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Sample records for parietal cortex abnormal

  1. Visual Categorization and the Parietal Cortex

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    Jamie K Fitzgerald

    2012-05-01

    Full Text Available The primate brain is adept at rapidly grouping items and events into functional classes, or categories, in order to recognize the significance of stimuli and guide behavior. Higher cognitive functions have traditionally been considered the domain of frontal areas. However, increasing evidence suggests that parietal cortex is also involved in categorical and associative processes. Previous work showed that the parietal cortex is highly involved in spatial processing, attention and saccadic eye movement planning, and more recent studies have found decision-making signals in LIP. We recently found that a subdivision of parietal cortex, the lateral intraparietal area (LIP, reflects learned categories for multiple types of visual stimuli. Additionally, a comparison of categorization signals in parietal and frontal areas found stronger and earlier categorization signals in parietal cortex, arguing that parietal abstract association or category signals are unlikely to arise via feedback from prefrontal cortex (PFC.

  2. Abnormal parietal function in conversion paresis.

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    Marije van Beilen

    Full Text Available The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study includes these different aspects in a single data set. In our study we included both normal controls and feigners to control for conversion paresis. We studied both movement execution and imagery, and we contrasted both within-group and between-group activation. Moreover, to reveal hemisphere-specific effects that have not been reported before, we performed these analyses using both flipped and unflipped data. This approach resulted in the identification of abnormal parietal activation which was specific for conversion paresis patients. Patients also showed reduced activity in the prefrontal cortex, supramarginal gyrus and precuneus, including hemisphere-specific activation that is lateralized in the same hemisphere, regardless of right- or left-sided paresis. We propose that these regions are candidates for an interface between psychological mechanisms and disturbed higher-order motor control. Our study presents an integrative neurophysiological view of the mechanisms that contribute to the etiology of this puzzling psychological disorder, which can be further investigated with other types of conversion symptoms.

  3. Navigating actions through the rodent parietal cortex

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    Jonathan R. Whitlock

    2014-05-01

    Full Text Available The posterior parietal cortex (PPC participates in a manifold of cognitive functions, including visual attention, working memory, spatial processing and movement planning. Given the vast interconnectivity of PPC with sensory and motor areas, it is not surprising that neuronal recordings show that PPC often encodes mixtures of spatial information as well as the movements required to reach a goal. Recent work sought to discern the relative strength of spatial versus motor signaling in PPC by recording single unit activity in PPC of freely behaving rats during selective changes in either the spatial layout of the local environment or in the pattern of locomotor behaviors executed during navigational tasks. The results revealed unequivocally a predominant sensitivity of PPC neurons to locomotor action structure, with subsets of cells even encoding upcoming movements more than 1 second in advance. In light of these and other recent findings in the field, I propose that one of the key contributions of PPC to navigation is the synthesis of goal-directed behavioral sequences, and that the rodent PPC may serve as an apt system to investigate cellular mechanisms for spatial motor planning as traditionally studied in humans and monkeys.

  4. Attenuating illusory binding with TMS of the right parietal cortex

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    Esterman, Michael; Verstynen, Timothy; Robertson, Lynn C.

    2007-01-01

    A number of neuroimaging and neuropsychology studies have implicated various regions of parietal cortex as playing a critical role in the binding of color and form into conjunctions. The current study investigates the role of two such regions by examining how parietal transcranial magnetic stimulation (TMS) influences binding errors known as ‘illusory conjunctions.’ Participants made fewer binding errors after 1 Hz rTMS of the right intraparietal sulcus (IPS), while basic perception of featur...

  5. Parietal cortex and representation of the mental Self

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    Lou, Hans C; Luber, Bruce; Crupain, Michael

    2004-01-01

    For a coherent and meaningful life, conscious self-representation is mandatory. Such explicit "autonoetic consciousness" is thought to emerge by retrieval of memory of personally experienced events ("episodic memory"). During episodic retrieval, functional imaging studies consistently show....... The medial parietal region may, then, be conceived of as a nodal structure in self-representation, functionally connected to both the right parietal and the medial prefrontal cortices. To determine whether medial parietal cortex in this network is essential for episodic memory retrieval with self...

  6. Neuronal synchronization in human parietal cortex during saccade planning

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    Werf, J. van der; Buchholz, V.N.; Jensen, O.; Medendorp, W.P.

    2009-01-01

    Neuropsychological and neuroimaging studies have implicated the human posterior parietal cortex (PPC) in sensorimotor integration and saccade planning However, the temporal dynamics of the underlying physiology and its relationship to observations in non-human primates have been difficult to pin

  7. Uncertain relational reasoning in the parietal cortex.

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    Ragni, Marco; Franzmeier, Imke; Maier, Simon; Knauff, Markus

    2016-04-01

    The psychology of reasoning is currently transitioning from the study of deductive inferences under certainty to inferences that have degrees of uncertainty in both their premises and conclusions; however, only a few studies have explored the cortical basis of uncertain reasoning. Using transcranial magnetic stimulation (TMS), we show that areas in the right superior parietal lobe (rSPL) are necessary for solving spatial relational reasoning problems under conditions of uncertainty. Twenty-four participants had to decide whether a single presented order of objects agreed with a given set of indeterminate premises that could be interpreted in more than one way. During the presentation of the order, 10-Hz TMS was applied over the rSPL or a sham control site. Right SPL TMS during the inference phase disrupted performance in uncertain relational reasoning. Moreover, we found differences in the error rates between preferred mental models, alternative models, and inconsistent models. Our results suggest that different mechanisms are involved when people reason spatially and evaluate different kinds of uncertain conclusions. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Functional connectivity of parietal cortex during temporal selective attention.

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    Tyler, Sarah C; Dasgupta, Samhita; Agosta, Sara; Battelli, Lorella; Grossman, Emily D

    2015-04-01

    Perception of natural experiences requires allocation of attention towards features, objects, and events that are moving and changing over time. This allocation of attention is controlled by large-scale brain networks that, when damaged, cause widespread cognitive deficits. In particular, damage to ventral parietal cortex (right lateralized TPJ, STS, supramarginal and angular gyri) is associated with failures to selectively attend to and isolate features embedded within rapidly changing visual sequences (Battelli, Pascual-Leone, & Cavanagh, 2007; Husain, Shapiro, Martin, & Kennard, 1997). In this study, we used fMRI to investigate the neural activity and functional connectivity of intact parietal cortex while typical subjects judged the relative onsets and offsets of rapidly flickering tokens (a phase discrimination task in which right parietal patients are impaired). We found two regions in parietal cortex correlated with task performance: a bilateral posterior TPJ (pTPJ) and an anterior right-lateralized TPJ (R aTPJ). Both regions were deactivated when subjects engaged in the task but showed different patterns of functional connectivity. The bilateral pTPJ was strongly connected to nodes within the default mode network (DMN) and the R aTPJ was connected to the attention network. Accurate phase discriminations were associated with increased functional correlations between sensory cortex (hMT+) and the bilateral pTPJ, whereas accuracy on a control task was associated with yoked activity in the hMT+ and the R aTPJ. We conclude that temporal selective attention is particularly sensitive for revealing information pathways between sensory and core cognitive control networks that, when damaged, can lead to nonspatial attention impairments in right parietal stroke patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Evolution of posterior parietal cortex and parietal-frontal networks for specific actions in primates.

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    Kaas, Jon H; Stepniewska, Iwona

    2016-02-15

    Posterior parietal cortex (PPC) is an extensive region of the human brain that develops relatively late and is proportionally large compared with that of monkeys and prosimian primates. Our ongoing comparative studies have led to several conclusions about the evolution of this posterior parietal region. In early placental mammals, PPC likely was a small multisensory region much like PPC of extant rodents and tree shrews. In early primates, PPC likely resembled that of prosimian galagos, in which caudal PPC (PPCc) is visual and rostral PPC (PPCr) has eight or more multisensory domains where electrical stimulation evokes different complex motor behaviors, including reaching, hand-to-mouth, looking, protecting the face or body, and grasping. These evoked behaviors depend on connections with functionally matched domains in premotor cortex (PMC) and motor cortex (M1). Domains in each region compete with each other, and a serial arrangement of domains allows different factors to influence motor outcomes successively. Similar arrangements of domains have been retained in New and Old World monkeys, and humans appear to have at least some of these domains. The great expansion and prolonged development of PPC in humans suggest the addition of functionally distinct territories. We propose that, across primates, PMC and M1 domains are second and third levels in a number of parallel, interacting networks for mediating and selecting one type of action over others. © 2015 Wiley Periodicals, Inc.

  10. Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation

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    Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin

    2011-01-01

    Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…

  11. Transient contribution of left posterior parietal cortex to cognitive restructuring.

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    Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

    2015-03-17

    Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring.

  12. Visual perception is dependent on visuospatial working memory and thus on the posterior parietal cortex.

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    Pisella, Laure

    2017-06-01

    Visual perception involves complex and active processes. We will start by explaining why visual perception is dependent on visuospatial working memory, especially the spatiotemporal integration of the perceived elements through the ocular exploration of visual scenes. Then we will present neuropsychology, transcranial magnetic stimulation and neuroimaging data yielding information on the specific role of the posterior parietal cortex of the right hemisphere in visuospatial working memory. Within the posterior parietal cortex, neuropsychology data also suggest that there might be dissociated neural substrates for deployment of attention (superior parietal lobules) and spatiotemporal integration (right inferior parietal lobule). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Motor role of parietal cortex in a monkey model of hemispatial neglect.

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    Kubanek, Jan; Li, Jingfeng M; Snyder, Lawrence H

    2015-04-21

    Parietal cortex is central to spatial cognition. Lesions of parietal cortex often lead to hemispatial neglect, an impairment of choices of targets in space. It has been unclear whether parietal cortex implements target choice at the general cognitive level, or whether parietal cortex subserves the choice of targets of particular actions. To address this question, monkeys engaged in choice tasks in two distinct action contexts--eye movements and arm movements. We placed focused reversible lesions into specific parietal circuits using the GABAA receptor agonist muscimol and validated the lesion placement using MRI. We found that lesions on the lateral bank of the intraparietal sulcus [lateral intraparietal area (LIP)] specifically biased choices made using eye movements, whereas lesions on the medial bank of the intraparietal sulcus [parietal reach region (PRR)] specifically biased choices made using arm movements. This double dissociation suggests that target choice is implemented in dedicated parietal circuits in the context of specific actions. This finding emphasizes a motor role of parietal cortex in spatial choice making and contributes to our understanding of hemispatial neglect.

  14. Subtle gray matter changes in temporo-parietal cortex associated with cardiovascular risk factors.

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    de Toledo Ferraz Alves, Tânia Corrêa; Scazufca, Márcia; Squarzoni, Paula; de Souza Duran, Fábio Luiz; Tamashiro-Duran, Jaqueline Hatsuko; Vallada, Homero P; Andrei, Anna; Wajngarten, Mauricio; Menezes, Paulo R; Busatto, Geraldo F

    2011-01-01

    Vascular risk factors may play an important role in the pathophysiology of Alzheimer's disease (AD). While there is consistent evidence of gray matter (GM) abnormalities in earlier stages of AD, the presence of more subtle GM changes associated with vascular risk factors in the absence of clinically significant vascular events has been scarcely investigated. This study aimed to examine GM changes in elderly subjects with cardiovascular risk factors. We predicted that the presence of cardiovascular risk would be associated with GM abnormalities involving the temporal-parietal cortices and limbic structures. We recruited 248 dementia-free subjects, age range 66-75 years, from the population-based "São Paulo Ageing and Health Study", classified in accordance to their Framingham Coronary Heart Disease Risk (FCHDR) score to undergo an MRI scan. We performed an overall analysis of covariance, controlled to total GM and APOE4 status, to investigate the presence of regional GM abnormalities in association with FCHDR subgroups (high-risk, medium-risk, and low-risk), and followed by post hoc t-test. We also applied a co-relational design in order to investigate the presence of linear progression of the GM vulnerability in association with cardiovascular risk factor. Voxel-based morphometry showed that the presence of cardiovascular risk factors were associated with regional GM loss involving the temporal cortices bilaterally. Those results retained statistical significance after including APOE4 as a covariate of interest. We also observed that there was a negative correlation between FCHDR scores and rGM distribution in the parietal cortex. Subclinical cerebrovascular abnormalities involving GM loss may provide an important link between cardiovascular risk factors and AD.

  15. The contribution of the human posterior parietal cortex to episodic memory

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    Sestieri, Carlo; Shulman, Gordon L.; Corbetta, Maurizio

    2017-01-01

    The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional–anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push–pull relationship, poten...

  16. Unique and shared roles of the posterior parietal and dorsolateral prefrontal cortex in cognitive functions

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    Fumi eKatsuki

    2012-05-01

    Full Text Available The dorsolateral prefrontal and posterior parietal cortex are two parts of a broader brain network involved in the control of cognitive functions such as working memory, spatial attention, and decision making. The two areas share many functional properties and exhibit similar patterns of activation during the execution of mental operations. However, neurophysiological experiments in non-human primates have also documented subtle differences, revealing functional specialization within the fronto-parietal network. These differences include the ability of the dorsolateral prefrontal cortex to influence memory performance, attention allocation and motor responses to a greater extent, and to resist interference by distracting stimuli. In recent years, distinct cellular and anatomical differences have been identified, offering insights into how functional specialization is achieved. This article reviews the common functions and functional differences between the dorsolateral prefrontal and posterior parietal cortex, and their underlying mechanisms.

  17. Right parietal cortex mediates recognition memory for melodies.

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    Schaal, Nora K; Javadi, Amir-Homayoun; Halpern, Andrea R; Pollok, Bettina; Banissy, Michael J

    2015-07-01

    Functional brain imaging studies have highlighted the significance of right-lateralized temporal, frontal and parietal brain areas for memory for melodies. The present study investigated the involvement of bilateral posterior parietal cortices (PPCs) for the recognition memory of melodies using transcranial direct current stimulation (tDCS). Participants performed a recognition task before and after tDCS. The task included an encoding phase (12 melodies), a retention period, as well as a recognition phase (24 melodies). Experiment 1 revealed that anodal tDCS over the right PPC led to a deterioration of overall memory performance compared with sham. Experiment 2 confirmed the results of Experiment 1 and further showed that anodal tDCS over the left PPC did not show a modulatory effect on memory task performance, indicating a right lateralization for musical memory. Furthermore, both experiments revealed that the decline in memory for melodies can be traced back to an interference of anodal stimulation on the recollection process (remember judgements) rather than to familiarity judgements. Taken together, this study revealed a causal involvement of the right PPC for memory for melodies and demonstrated a key role for this brain region in the recollection process of the memory task. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  18. Seeing is not feeling: posterior parietal but not somatosensory cortex engagement during touch observation.

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    Chan, Annie W-Y; Baker, Chris I

    2015-01-28

    Observing touch has been reported to elicit activation in human primary and secondary somatosensory cortices and is suggested to underlie our ability to interpret other's behavior and potentially empathy. However, despite these reports, there are a large number of inconsistencies in terms of the precise topography of activation, the extent of hemispheric lateralization, and what aspects of the stimulus are necessary to drive responses. To address these issues, we investigated the localization and functional properties of regions responsive to observed touch in a large group of participants (n = 40). Surprisingly, even with a lenient contrast of hand brushing versus brushing alone, we did not find any selective activation for observed touch in the hand regions of somatosensory cortex but rather in superior and inferior portions of neighboring posterior parietal cortex, predominantly in the left hemisphere. These regions in the posterior parietal cortex required the presence of both brush and hand to elicit strong responses and showed some selectivity for the form of the object or agent of touch. Furthermore, the inferior parietal region showed nonspecific tactile and motor responses, suggesting some similarity to area PFG in the monkey. Collectively, our findings challenge the automatic engagement of somatosensory cortex when observing touch, suggest mislocalization in previous studies, and instead highlight the role of posterior parietal cortex. Copyright © 2015 the authors 0270-6474/15/351468-13$15.00/0.

  19. Transcranial direct current stimulation over the parietal cortex alters bias in item and source memory tasks.

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    Pergolizzi, Denise; Chua, Elizabeth F

    2016-10-01

    Neuroimaging data have shown that activity in the lateral posterior parietal cortex (PPC) correlates with item recognition and source recollection, but there is considerable debate about its specific contributions. Performance on both item and source memory tasks were compared between participants who were given bilateral transcranial direct current stimulation (tDCS) over the parietal cortex to those given prefrontal or sham tDCS. The parietal tDCS group, but not the prefrontal group, showed decreased false recognition, and less bias in item and source discrimination tasks compared to sham stimulation. These results are consistent with a causal role of the PPC in item and source memory retrieval, likely based on attentional and decision-making biases. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Induction of motor associative plasticity in the posterior parietal cortex-primary motor network

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    Chao, Chi-Chao; Karabanov, Anke Ninija; Paine, Rainer

    2015-01-01

    There is anatomical and functional connectivity between the primary motor cortex (M1) and posterior parietal cortex (PPC) that plays a role in sensorimotor integration. In this study, we applied corticocortical paired-associative stimuli to ipsilateral PPC and M1 (parietal ccPAS) in healthy right......-handed subjects to test if this procedure could modulate M1 excitability and PPC–M1 connectivity. One hundred and eighty paired transcranial magnetic stimuli to the PPC and M1 at an interstimulus interval (ISI) of 8 ms were delivered at 0.2 Hz. We found that parietal ccPAS in the left hemisphere increased...... the excitability of conditioned left M1 assessed by motor evoked potentials (MEPs) and the input–output curve. Motor behavior assessed by the Purdue pegboard task was unchanged compared with controls. At baseline, conditioning stimuli over the left PPC potentiated MEPs from left M1 when ISI was 8 ms...

  1. Intrinsic connections and architectonics of posterior parietal cortex in the rhesus monkey

    International Nuclear Information System (INIS)

    Pandya, D.N.; Seltzer, B.

    1982-01-01

    By means of autoradiographic and ablation-degeneration techniques, the intrinsic cortical connections of the posterior parietal cortex in the rhesus monkey were traced and correlated with a reappraisal of cerebral architectonics. Two major rostral-to-caudal connectional sequences exist. One begins in the dorsal postcentral gyrus (area 2) and proceeds, through architectonic divisions of the superior parietal lobule (areas PE and PEc), to a cortical region on the medial surface of the parietal lobe (area PGm). This area has architectonic features similar to those of the caudal inferior parietal lobule (area PG). The second sequence begins in the ventral post/central gyrus (area 2) and passes through the rostral inferior parietal lobule (areas PG and PFG) to reach the caudal inferior parietal lobule (area PG). Both the superior parietal lobule and the rostral inferior parietal lobule also send projections to various other zones located in the parietal opercular region, the intraparietal sulcus, and the caudalmost portion of the cingulate sulcus. Areas PGm and PG, on the other hand, project to each other, to the cingulate region, to the caudalmost portion of the superior temporal gyrus, and to the upper bank of the superior temporal sulcus. Finally, a reciprocal sequence of connections, directed from caudal to rostral, links together many of the above-mentioned parietal zones. With regard to the laminar pattern of termination, the rostral-to-caudal connections are primarily distributed in the form of cortical ''columns'' while the caudal-to-rostral connections are found mainly over the first cortical cell layer

  2. Attentional Demands Predict Short-Term Memory Load Response in Posterior Parietal Cortex

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    Magen, Hagit; Emmanouil, Tatiana-Aloi; McMains, Stephanie A.; Kastner, Sabine; Treisman, Anne

    2009-01-01

    Limits to the capacity of visual short-term memory (VSTM) indicate a maximum storage of only 3 or 4 items. Recently, it has been suggested that activity in a specific part of the brain, the posterior parietal cortex (PPC), is correlated with behavioral estimates of VSTM capacity and might reflect a capacity-limited store. In three experiments that…

  3. Differential Recruitment of Parietal Cortex during Spatial and Non-spatial Reach Planning

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    Pierre-Michel Bernier

    2017-05-01

    Full Text Available The planning of goal-directed arm reaching movements is associated with activity in the dorsal parieto-frontal cortex, within which multiple regions subserve the integration of arm- and target-related sensory signals to encode a motor goal. Surprisingly, many of these regions show sustained activity during reach preparation even when target location is not specified, i.e., when a motor goal cannot be unambiguously formed. The functional role of these non-spatial preparatory signals remains unresolved. Here this process was investigated in humans by comparing reach preparatory activity in the presence or absence of information regarding upcoming target location. In order to isolate the processes specific to reaching and to control for visuospatial attentional factors, the reaching task was contrasted to a finger movement task. Functional MRI and electroencephalography (EEG were used to characterize the spatio-temporal pattern of reach-related activity in the parieto-frontal cortex. Reach planning with advance knowledge of target location induced robust blood oxygenated level dependent and EEG responses across parietal and premotor regions contralateral to the reaching arm. In contrast, reach preparation without knowledge of target location was associated with a significant BOLD response bilaterally in the parietal cortex. Furthermore, EEG alpha- and beta-band activity was restricted to parietal scalp sites, the magnitude of the latter being correlated with reach reaction times. These results suggest an intermediate stage of sensorimotor transformations in bilateral parietal cortex when target location is not specified.

  4. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

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    Andreas A Ioannides

    2013-08-01

    Full Text Available Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1 and motor (M1 cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45 to 70 Hz activity at latencies of 20 to 50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occured in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

  5. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject.

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    Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe; Saridis, George A; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

    2013-01-01

    Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

  6. Grasp movement decoding from premotor and parietal cortex.

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    Townsend, Benjamin R; Subasi, Erk; Scherberger, Hansjörg

    2011-10-05

    Despite recent advances in harnessing cortical motor-related activity to control computer cursors and robotic devices, the ability to decode and execute different grasping patterns remains a major obstacle. Here we demonstrate a simple Bayesian decoder for real-time classification of grip type and wrist orientation in macaque monkeys that uses higher-order planning signals from anterior intraparietal cortex (AIP) and ventral premotor cortex (area F5). Real-time decoding was based on multiunit signals, which had similar tuning properties to cells in previous single-unit recording studies. Maximum decoding accuracy for two grasp types (power and precision grip) and five wrist orientations was 63% (chance level, 10%). Analysis of decoder performance showed that grip type decoding was highly accurate (90.6%), with most errors occurring during orientation classification. In a subsequent off-line analysis, we found small but significant performance improvements (mean, 6.25 percentage points) when using an optimized spike-sorting method (superparamagnetic clustering). Furthermore, we observed significant differences in the contributions of F5 and AIP for grasp decoding, with F5 being better suited for classification of the grip type and AIP contributing more toward decoding of object orientation. However, optimum decoding performance was maximal when using neural activity simultaneously from both areas. Overall, these results highlight quantitative differences in the functional representation of grasp movements in AIP and F5 and represent a first step toward using these signals for developing functional neural interfaces for hand grasping.

  7. Distinct Oscillatory Frequencies Underlie Excitability of Human Occipital and Parietal Cortex.

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    Samaha, Jason; Gosseries, Olivia; Postle, Bradley R

    2017-03-15

    Transcranial magnetic stimulation (TMS) of human occipital and posterior parietal cortex can give rise to visual sensations called phosphenes. We used near-threshold TMS with concurrent EEG recordings to measure how oscillatory brain dynamics covary, on single trials, with the perception of phosphenes after occipital and parietal TMS. Prestimulus power and phase, predominantly in the alpha band (8-13 Hz), predicted occipital TMS phosphenes, whereas higher-frequency beta-band (13-20 Hz) power (but not phase) predicted parietal TMS phosphenes. TMS-evoked responses related to phosphene perception were similar across stimulation sites and were characterized by an early (200 ms) posterior negativity and a later (>300 ms) parietal positivity in the time domain and an increase in low-frequency (∼5-7 Hz) power followed by a broadband decrease in alpha/beta power in the time-frequency domain. These correlates of phosphene perception closely resemble known electrophysiological correlates of conscious perception of near-threshold visual stimuli. The regionally differential pattern of prestimulus predictors of phosphene perception suggests that distinct frequencies may reflect cortical excitability in occipital versus posterior parietal cortex, calling into question the broader assumption that the alpha rhythm may serve as a general index of cortical excitability. SIGNIFICANCE STATEMENT Alpha-band oscillations are thought to reflect cortical excitability and are therefore ascribed an important role in gating information transmission across cortex. We probed cortical excitability directly in human occipital and parietal cortex and observed that, whereas alpha-band dynamics indeed reflect excitability of occipital areas, beta-band activity was most predictive of parietal cortex excitability. Differences in the state of cortical excitability predicted perceptual outcomes (phosphenes), which were manifest in both early and late patterns of evoked activity, revealing the time

  8. The role of parietal cortex in the formation of colour and motion based concepts

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    Samuel William Cheadle

    2014-07-01

    Full Text Available Imaging evidence shows that separate subdivisions of parietal cortex, in and around the intraparietal sulcus (IPS, are engaged when stimuli are grouped according to colour and to motion (Zeki and Stutters 2013. Since grouping is an essential step in the formation of concepts, we wanted to learn whether parietal cortex is also engaged in the formation of concepts according to these two attributes. Using functional magnetic resonance imaging (fMRI, and choosing the recognition of concept-based colour or motion stimuli as our paradigm, we found that there was strong concept-related activity in and around the intraparietal sulcus (IPS, a region whose homologue in the macaque monkey is known to receive direct but segregated anatomical inputs from V4 and V5. Parietal activity related to colour concepts was juxtaposed but did not overlap with activity related to motion concepts, thus emphasizing the continuation of the segregation of colour and motion into the conceptual system. Concurrent retinotopic mapping experiments showed that within the parietal cortex, concept-related activity increases within later stage IPS areas.

  9. Enhanced Working Memory Binding by Direct Electrical Stimulation of the Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Agustina Birba

    2017-06-01

    Full Text Available Recent works evince the critical role of visual short-term memory (STM binding deficits as a clinical and preclinical marker of Alzheimer’s disease (AD. These studies suggest a potential role of posterior brain regions in both the neurocognitive deficits of Alzheimer’s patients and STM binding in general. Thereupon, we surmised that stimulation of the posterior parietal cortex (PPC might be a successful approach to tackle working memory deficits in this condition, especially at early stages. To date, no causal evidence exists of the role of the parietal cortex in STM binding. A unique approach to assess this issue is afforded by single-subject direct intracranial electrical stimulation of specific brain regions during a relevant cognitive task. Electrical stimulation has been used both for clinical purposes and to causally probe brain mechanisms. Previous evidence of electrical currents spreading through white matter along well defined functional circuits indicates that visual working memory mechanisms are subserved by a specific widely distributed network. Here, we stimulated the parietal cortex of a subject with intracranial electrodes as he performed the visual STM task. We compared the ensuing results to those from a non-stimulated condition and to the performance of a matched control group. In brief, direct stimulation of the parietal cortex induced a selective improvement in STM. These results, together with previous studies, provide very preliminary but promising ground to examine behavioral changes upon parietal stimulation in AD. We discuss our results regarding: (a the usefulness of the task to target prodromal stages of AD; (b the role of a posterior network in STM binding and in AD; and (c the potential opportunity to improve STM binding through brain stimulation.

  10. The contribution of the human posterior parietal cortex to episodic memory.

    Science.gov (United States)

    Sestieri, Carlo; Shulman, Gordon L; Corbetta, Maurizio

    2017-02-17

    The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional-anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push-pull relationship, potentially mediated by prefrontal regions. Moreover, different PPC regions carry out specific functions during retrieval - for example, representing retrieved information, recoding this information based on task demands, or accumulating evidence for memory decisions.

  11. Timing-dependent modulation of the posterior parietal cortex-primary motor cortex pathway by sensorimotor training

    DEFF Research Database (Denmark)

    Karabanov, Anke Ninija; Jin, Seung-Hyun; Joutsen, Atte

    2012-01-01

    at baseline and at four time points (0, 30, 60, and 180 min) after training. For EEG, task-related power and coherence were calculated for early and late training phases. The conditioned MEP was facilitated at a 2-ms conditioning-test interval before training. However, facilitation was abolished immediately...... following training, but returned to baseline at subsequent time points. Regional EEG activity and interregional connectivity between PPC and M1 showed an initial increase during early training followed by a significant decrease in the late phases. The findings indicate that parietal-motor interactions......Interplay between posterior parietal cortex (PPC) and ipsilateral primary motor cortex (M1) is crucial during execution of movements. The purpose of the study was to determine whether functional PPC-M1 connectivity in humans can be modulated by sensorimotor training. Seventeen participants...

  12. Neural sources of visual working memory maintenance in human parietal and ventral extrastriate visual cortex.

    Science.gov (United States)

    Becke, Andreas; Müller, Notger; Vellage, Anne; Schoenfeld, Mircea Ariel; Hopf, Jens-Max

    2015-04-15

    Maintaining information in visual working memory is reliably indexed by the contralateral delay activity (CDA) - a sustained modulation of the event-related potential (ERP) with a topographical maximum over posterior scalp regions contralateral to the memorized input. Based on scalp topography, it is hypothesized that the CDA reflects neural activity in the parietal cortex, but the precise cortical origin of underlying electric activity was never determined. Here we combine ERP recordings with magnetoencephalography based source localization to characterize the cortical current sources generating the CDA. Observers performed a cued delayed match to sample task where either the color or the relative position of colored dots had to be maintained in memory. A detailed source-localization analysis of the magnetic activity in the retention interval revealed that the magnetic analog of the CDA (mCDA) is generated by current sources in the parietal cortex. Importantly, we find that the mCDA also receives contribution from current sources in the ventral extrastriate cortex that display a time-course similar to the parietal sources. On the basis of the magnetic responses, forward modeling of ERP data reveals that the ventral sources have non-optimal projections and that these sources are therefore concealed in the ERP by overlapping fields with parietal projections. The present observations indicate that visual working memory maintenance, as indexed by the CDA, involves the parietal cortical regions as well as the ventral extrastriate regions, which code the sensory representation of the memorized content. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Neural representations of social status hierarchy in human inferior parietal cortex.

    Science.gov (United States)

    Chiao, Joan Y; Harada, Tokiko; Oby, Emily R; Li, Zhang; Parrish, Todd; Bridge, Donna J

    2009-01-01

    Mental representations of social status hierarchy share properties with that of numbers. Previous neuroimaging studies have shown that the neural representation of numerical magnitude lies within a network of regions within inferior parietal cortex. However the neural basis of social status hierarchy remains unknown. Using fMRI, we studied subjects while they compared social status magnitude of people, objects and symbols, as well as numerical magnitude. Both social status and number comparisons recruited bilateral intraparietal sulci. We also observed a semantic distance effect whereby neural activity within bilateral intraparietal sulci increased for semantically close relative to far numerical and social status comparisons. These results demonstrate that social status and number comparisons recruit distinct and overlapping neuronal representations within human inferior parietal cortex.

  14. Characterization of visual percepts evoked by noninvasive stimulation of the human posterior parietal cortex.

    Directory of Open Access Journals (Sweden)

    Peter J Fried

    Full Text Available Phosphenes are commonly evoked by transcranial magnetic stimulation (TMS to study the functional organization, connectivity, and excitability of the human visual brain. For years, phosphenes have been documented only from stimulating early visual areas (V1-V3 and a handful of specialized visual regions (V4, V5/MT+ in occipital cortex. Recently, phosphenes were reported after applying TMS to a region of posterior parietal cortex involved in the top-down modulation of visuo-spatial processing. In the present study, we systematically characterized parietal phosphenes to determine if they are generated directly by local mechanisms or emerge through indirect activation of other visual areas. Using technology developed in-house to record the subjective features of phosphenes, we found no systematic differences in the size, shape, location, or frame-of-reference of parietal phosphenes when compared to their occipital counterparts. In a second experiment, discrete deactivation by 1 Hz repetitive TMS yielded a double dissociation: phosphene thresholds increased at the deactivated site without producing a corresponding change at the non-deactivated location. Overall, the commonalities of parietal and occipital phosphenes, and our ability to independently modulate their excitability thresholds, lead us to conclude that they share a common neural basis that is separate from either of the stimulated regions.

  15. Posterior parietal cortex and long-term memory: some data from laboratory animals

    OpenAIRE

    Myskiw, Jociane C.; Izquierdo, Iván

    2012-01-01

    The posterior parietal cortex (PPC) was long viewed as just involved in the perception of spatial relationships between the body and its surroundings and of movements related to them. In recent years the PPC has been shown to participate in many other cognitive processes, among which working memory and the consolidation and retrieval of episodic memory. The neurotransmitter and other molecular processes involved have been determined to a degree in rodents. More research will no doubt determin...

  16. Connections of the medial posterior parietal cortex (area 7m) in the monkey.

    Science.gov (United States)

    Leichnetz, G R

    2001-06-01

    The afferent and efferent cortical and subcortical connections of the medial posterior parietal cortex (area 7m) were studied in cebus (Cebus apella) and macaque (Macaca fascicularis) monkeys using the retrograde and anterograde capabilities of the horseradish peroxidase (HRP) technique. The principal intraparietal corticocortical connections of area 7m in both cebus and macaque cases were with the ipsilateral medial bank of the intraparietal sulcus (MIP) and adjacent superior parietal lobule (area 5), inferior parietal lobule (area 7a), lateral bank of the IPS (area 7ip), caudal parietal operculum (PGop), dorsal bank of the caudal superior temporal sulcus (visual area MST), and medial prestriate cortex (including visual area PO and caudal medial lobule). Its principal frontal corticocortical connections were with the prefrontal cortex in the shoulder above the principal sulcus and the cortex in the shoulder above the superior ramus of the arcuate sulcus (SAS), the area purported to contain the smooth eye movement-related frontal eye field (FEFsem) in the cebus monkey by other investigators. There were moderate connections with the cortex in the rostral bank of the arcuate sulcus (purported to contain the saccade-related frontal eye field; FEFsac), supplementary eye field (SEF), and rostral dorsal premotor area (PMDr). Area 7m also had major connections with the cingulate cortex (area 23), particularly the ventral bank of the cingulate sulcus. The principal subcortical connections of area 7m were with the dorsal portion of the ventrolateral thalamic (VLc) nucleus, lateral posterior thalamic nucleus, lateral pulvinar, caudal mediodorsal thalamic nucleus and medial pulvinar, central lateral, central superior lateral, and central inferior intralaminar thalamic nuclei, dorsolateral caudate nucleus and putamen, middle region of the claustrum, nucleus of the diagonal band, zona incerta, pregeniculate nucleus, anterior and posterior pretectal nuclei, intermediate layer of

  17. Asymmetric multisensory interactions of visual and somatosensory responses in a region of the rat parietal cortex.

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    Michael T Lippert

    Full Text Available Perception greatly benefits from integrating multiple sensory cues into a unified percept. To study the neural mechanisms of sensory integration, model systems are required that allow the simultaneous assessment of activity and the use of techniques to affect individual neural processes in behaving animals. While rodents qualify for these requirements, little is known about multisensory integration and areas involved for this purpose in the rodent. Using optical imaging combined with laminar electrophysiological recordings, the rat parietal cortex was identified as an area where visual and somatosensory inputs converge and interact. Our results reveal similar response patterns to visual and somatosensory stimuli at the level of current source density (CSD responses and multi-unit responses within a strip in parietal cortex. Surprisingly, a selective asymmetry was observed in multisensory interactions: when the somatosensory response preceded the visual response, supra-linear summation of CSD was observed, but the reverse stimulus order resulted in sub-linear effects in the CSD. This asymmetry was not present in multi-unit activity however, which showed consistently sub-linear interactions. These interactions were restricted to a specific temporal window, and pharmacological tests revealed significant local intra-cortical contributions to this phenomenon. Our results highlight the rodent parietal cortex as a system to model the neural underpinnings of multisensory processing in behaving animals and at the cellular level.

  18. Posterior parietal cortex mediates encoding and maintenance processes in change blindness.

    Science.gov (United States)

    Tseng, Philip; Hsu, Tzu-Yu; Muggleton, Neil G; Tzeng, Ovid J L; Hung, Daisy L; Juan, Chi-Hung

    2010-03-01

    It is commonly accepted that right posterior parietal cortex (PPC) plays an important role in updating spatial representations, directing visuospatial attention, and planning actions. However, recent studies suggest that right PPC may also be involved in processes that are more closely associated with our visual awareness as its activation level positively correlates with successful conscious change detection (Beck, D.M., Rees, G., Frith, C.D., & Lavie, N. (2001). Neural correlates of change detection and change blindness. Nature Neuroscience, 4, 645-650.). Furthermore, disruption of its activity increases the occurrences of change blindness, thus suggesting a causal role for right PPC in change detection (Beck, D.M., Muggleton, N., Walsh, V., & Lavie, N. (2006). Right parietal cortex plays a critical role in change blindness. Cerebral Cortex, 16, 712-717.). In the context of a 1-shot change detection paradigm, we applied transcranial magnetic stimulation (TMS) during different time intervals to elucidate the temporally precise involvement of PPC in change detection. While subjects attempted to detect changes between two image sets separated by a brief time interval, TMS was applied either during the presentation of picture 1 when subjects were encoding and maintaining information into visual short-term memory, or picture 2 when subjects were retrieving information relating to picture 1 and comparing it to picture 2. Our results show that change blindness occurred more often when TMS was applied during the viewing of picture 1, which implies that right PPC plays a crucial role in the processes of encoding and maintaining information in visual short-term memory. In addition, since our stimuli did not involve changes in spatial locations, our findings also support previous studies suggesting that PPC may be involved in the processes of encoding non-spatial visual information (Todd, J.J. & Marois, R. (2004). Capacity limit of visual short-term memory in human

  19. Prediction of Reach Goals in Depth and Direction from the Parietal Cortex

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    Matteo Filippini

    2018-04-01

    Full Text Available Summary: The posterior parietal cortex is well known to mediate sensorimotor transformations during the generation of movement plans, but its ability to control prosthetic limbs in 3D environments has not yet been fully demonstrated. With this aim, we trained monkeys to perform reaches to targets located at various depths and directions and tested whether the reach goal position can be extracted from parietal signals. The reach goal location was reliably decoded with accuracy close to optimal (>90%, and this occurred also well before movement onset. These results, together with recent work showing a reliable decoding of hand grip in the same area, suggest that this is a suitable site to decode the entire prehension action, to be considered in the development of brain-computer interfaces. : Filippini et al. show that it is possible to use parietal cortex activity to predict in which direction the arm will move and how far it will reach. This opens up the possibility of neural prostheses that can accurately guide reach and grasp using signals from this part of the brain. Keywords: neuroprosthetics, offline neural decoding, reaching in depth, monkey, V6A, machine learning, visuomotor transformations, hand guidance, prehension, robotics

  20. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

    DEFF Research Database (Denmark)

    Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe

    2013-01-01

    magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified...... reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann...... of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first...

  1. Integration of Visual and Proprioceptive Limb Position Information in Human Posterior Parietal, Premotor, and Extrastriate Cortex.

    Science.gov (United States)

    Limanowski, Jakub; Blankenburg, Felix

    2016-03-02

    The brain constructs a flexible representation of the body from multisensory information. Previous work on monkeys suggests that the posterior parietal cortex (PPC) and ventral premotor cortex (PMv) represent the position of the upper limbs based on visual and proprioceptive information. Human experiments on the rubber hand illusion implicate similar regions, but since such experiments rely on additional visuo-tactile interactions, they cannot isolate visuo-proprioceptive integration. Here, we independently manipulated the position (palm or back facing) of passive human participants' unseen arm and of a photorealistic virtual 3D arm. Functional magnetic resonance imaging (fMRI) revealed that matching visual and proprioceptive information about arm position engaged the PPC, PMv, and the body-selective extrastriate body area (EBA); activity in the PMv moreover reflected interindividual differences in congruent arm ownership. Further, the PPC, PMv, and EBA increased their coupling with the primary visual cortex during congruent visuo-proprioceptive position information. These results suggest that human PPC, PMv, and EBA evaluate visual and proprioceptive position information and, under sufficient cross-modal congruence, integrate it into a multisensory representation of the upper limb in space. The position of our limbs in space constantly changes, yet the brain manages to represent limb position accurately by combining information from vision and proprioception. Electrophysiological recordings in monkeys have revealed neurons in the posterior parietal and premotor cortices that seem to implement and update such a multisensory limb representation, but this has been difficult to demonstrate in humans. Our fMRI experiment shows that human posterior parietal, premotor, and body-selective visual brain areas respond preferentially to a virtual arm seen in a position corresponding to one's unseen hidden arm, while increasing their communication with regions conveying visual

  2. Improving ideomotor limb apraxia by electrical stimulation of the left posterior parietal cortex.

    Science.gov (United States)

    Bolognini, Nadia; Convento, Silvia; Banco, Elisabetta; Mattioli, Flavia; Tesio, Luigi; Vallar, Giuseppe

    2015-02-01

    Limb apraxia, a deficit of planning voluntary gestures, is most frequently caused by damage to the left hemisphere, where, according to an influential neurofunctional model, gestures are planned, before being executed through the motor cortex of the hemisphere contralateral to the acting hand. We used anodal transcranial direct current stimulation delivered to the left posterior parietal cortex (PPC), the right motor cortex (M1), and a sham stimulation condition, to modulate the ability of six left-brain-damaged patients with ideomotor apraxia, and six healthy control subjects, to imitate hand gestures, and to perform skilled hand movements using the left hand. Transcranial direct current stimulation delivered to the left PPC reduced the time required to perform skilled movements, and planning, but not execution, times in imitating gestures, in both patients and controls. In patients, the amount of decrease of planning times brought about by left PPC transcranial direct current stimulation was influenced by the size of the parietal lobe damage, with a larger parietal damage being associated with a smaller improvement. Of interest from a clinical perspective, left PPC stimulation also ameliorated accuracy in imitating hand gestures in patients. Instead, transcranial direct current stimulation to the right M1 diminished execution, but not planning, times in both patients and healthy controls. In conclusion, by using a transcranial stimulation approach, we temporarily improved ideomotor apraxia in the left hand of left-brain-damaged patients, showing a role of the left PPC in planning gestures. This evidence opens up novel perspectives for the use of transcranial direct current stimulation in the rehabilitation of limb apraxia. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Role of the right inferior parietal cortex in auditory selective attention: An rTMS study.

    Science.gov (United States)

    Bareham, Corinne A; Georgieva, Stanimira D; Kamke, Marc R; Lloyd, David; Bekinschtein, Tristan A; Mattingley, Jason B

    2018-02-01

    Selective attention is the process of directing limited capacity resources to behaviourally relevant stimuli while ignoring competing stimuli that are currently irrelevant. Studies in healthy human participants and in individuals with focal brain lesions have suggested that the right parietal cortex is crucial for resolving competition for attention. Following right-hemisphere damage, for example, patients may have difficulty reporting a brief, left-sided stimulus if it occurs with a competitor on the right, even though the same left stimulus is reported normally when it occurs alone. Such "extinction" of contralesional stimuli has been documented for all the major sense modalities, but it remains unclear whether its occurrence reflects involvement of one or more specific subregions of the temporo-parietal cortex. Here we employed repetitive transcranial magnetic stimulation (rTMS) over the right hemisphere to examine the effect of disruption of two candidate regions - the supramarginal gyrus (SMG) and the superior temporal gyrus (STG) - on auditory selective attention. Eighteen neurologically normal, right-handed participants performed an auditory task, in which they had to detect target digits presented within simultaneous dichotic streams of spoken distractor letters in the left and right channels, both before and after 20 min of 1 Hz rTMS over the SMG, STG or a somatosensory control site (S1). Across blocks, participants were asked to report on auditory streams in the left, right, or both channels, which yielded focused and divided attention conditions. Performance was unchanged for the two focused attention conditions, regardless of stimulation site, but was selectively impaired for contralateral left-sided targets in the divided attention condition following stimulation of the right SMG, but not the STG or S1. Our findings suggest a causal role for the right inferior parietal cortex in auditory selective attention. Copyright © 2017 Elsevier Ltd. All rights

  4. The flexible use of multiple cue relationships in spatial navigation : A comparison of water maze performance following hippocampal, medial septal, prefrontal cortex, or posterior parietal cortex lesions

    NARCIS (Netherlands)

    Compton, DM; Griffith, HR; McDaniel, WF; Foster, RA; Davis, BK

    Rats prepared with lesions of the prefrontal cortex, posterior parietal cortex, hippocampus, or medial septal area were tested for acquisition of a number of variations of the open-field water maze using a version of place learning assessment described by Eichenbaum, Stewart, and Morris (1991).

  5. Mechanisms within the Parietal Cortex Correlate with the Benefits of Random Practice in Motor Adaptation

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    Benjamin Thürer

    2017-08-01

    Full Text Available The motor learning literature shows an increased retest or transfer performance after practicing under unstable (random conditions. This random practice effect (also known as contextual interference effect is frequently investigated on the behavioral level and discussed in the context of mechanisms of the dorsolateral prefrontal cortex and increased cognitive efforts during movement planning. However, there is a lack of studies examining the random practice effect in motor adaptation tasks and, in general, the underlying neural processes of the random practice effect are not fully understood. We tested 24 right-handed human subjects performing a reaching task using a robotic manipulandum. Subjects learned to adapt either to a blocked or a random schedule of different force field perturbations while subjects’ electroencephalography (EEG was recorded. The behavioral results showed a distinct random practice effect in terms of a more stabilized retest performance of the random compared to the blocked practicing group. Further analyses showed that this effect correlates with changes in the alpha band power in electrodes over parietal areas. We conclude that the random practice effect in this study is facilitated by mechanisms within the parietal cortex during movement execution which might reflect online feedback mechanisms.

  6. Effect of transcranial magnetic stimulation (TMS on parietal and premotor cortex during planning of reaching movements.

    Directory of Open Access Journals (Sweden)

    Pierpaolo Busan

    Full Text Available BACKGROUND: Cerebral activation during planning of reaching movements occurs both in the superior parietal lobule (SPL and premotor cortex (PM, and their activation seems to take place in parallel. METHODOLOGY: The activation of the SPL and PM has been investigated using transcranial magnetic stimulation (TMS during planning of reaching movements under visual guidance. PRINCIPAL FINDINGS: A facilitory effect was found when TMS was delivered on the parietal cortex at about half of the time from sight of the target to hand movement, independently of target location in space. Furthermore, at the same stimulation time, a similar facilitory effect was found in PM, which is probably related to movement preparation. CONCLUSIONS: This data contributes to the understanding of cortical dynamics in the parieto-frontal network, and suggests that it is possible to interfere with the planning of reaching movements at different cortical points within a particular time window. Since similar effects may be produced at similar times on both the SPL and PM, parallel processing of visuomotor information is likely to take place in these regions.

  7. Endoplasmic reticulum stress responses differ in meninges and associated vasculature, striatum, and parietal cortex after a neurotoxic amphetamine exposure.

    Science.gov (United States)

    Thomas, Monzy; George, Nysia I; Saini, Upasana T; Patterson, Tucker A; Hanig, Joseph P; Bowyer, John F

    2010-08-01

    Amphetamine (AMPH) is used to treat attention deficit and hyperactivity disorders, but it can produce neurotoxicity and adverse vascular effects at high doses. The endoplasmic reticulum (ER) stress response (ERSR) entails the unfolded protein response, which helps to avoid or minimize ER dysfunction. ERSR is often associated with toxicities resulting from the accumulation of unfolded or misfolded proteins and has been associated with methamphetamine toxicity in the striatum. The present study evaluates the effect of AMPH on several ERSR elements in meninges and associated vasculature (MAV), parietal cortex, and striatum. Adult, male Sprague-Dawley rats were exposed to saline, environmentally induced hyperthermia (EIH) or four consecutive doses of AMPH that produce hyperthermia. Expression changes (mRNA and protein levels) of key ERSR-related genes in MAV, striatum, and parietal cortex at 3 h or 1 day postdosing were monitored. AMPH increased the expression of some ERSR-related genes in all tissues. Atf4 (activating transcription factor 4, an indicator of Perk pathway activation), Hspa5/Grp78 (Glucose regulated protein 78, master regulator of ERSR), Pdia4 (protein disulfide isomerase, protein-folding enzyme), and Nfkb1 (nuclear factor of kappa b, ERSR sensor) mRNA increased significantly in MAV and parietal cortex 3 h after AMPH. In striatum, Atf4 and Hspa5/Grp78 mRNA significantly increased 3 h after AMPH, but Pdia4 and Nfkb11 did not. Thus, AMPH caused a robust activation of the Perk pathway in all tissues, but significant Ire1 pathway activation occurred only after AMPH treatment in the parietal cortex and striatum. Ddit3/Chop, a downstream effector of the ERSR pathway related to the neurotoxicity, was only increased in striatum and parietal cortex. Conversely, Pdia4, an enzyme protective in the ERSR, was only increased in MAV. The overall ERSR manifestation varied significantly between MAV, striatum, and parietal cortex after a neurotoxic exposure to AMPH.

  8. The role of inferior parietal and inferior frontal cortex in working memory.

    Science.gov (United States)

    Baldo, Juliana V; Dronkers, Nina F

    2006-09-01

    Verbal working memory involves two major components: a phonological store that holds auditory-verbal information very briefly and an articulatory rehearsal process that allows that information to be refreshed and thus held longer in short-term memory (A. Baddeley, 1996, 2000; A. Baddeley & G. Hitch, 1974). In the current study, the authors tested two groups of patients who were chosen on the basis of their relatively focal lesions in the inferior parietal (IP) cortex or inferior frontal (IF) cortex. Patients were tested on a series of tasks that have been previously shown to tap phonological storage (span, auditory rhyming, and repetition) and articulatory rehearsal (visual rhyming and a 2-back task). As predicted, IP patients were disproportionately impaired on the span, rhyming, and repetition tasks and thus demonstrated a phonological storage deficit. IF patients, however, did not show impairment on these storage tasks but did exhibit impairment on the visual rhyming task, which requires articulatory rehearsal. These findings lend further support to the working memory model and provide evidence of the roles of IP and IF cortex in separable working memory processes. ((c) 2006 APA, all rights reserved).

  9. Activation of right parietal cortex during memory retrieval of nonlinguistic auditory stimuli.

    Science.gov (United States)

    Klostermann, Ellen C; Loui, Psyche; Shimamura, Arthur P

    2009-09-01

    In neuroimaging studies, the left ventral posterior parietal cortex (PPC) is particularly active during memory retrieval. However, most studies have used verbal or verbalizable stimuli. We investigated neural activations associated with the retrieval of short, agrammatical music stimuli (Blackwood, 2004), which have been largely associated with right hemisphere processing. At study, participants listened to music stimuli and rated them on pleasantness. At test, participants made old/new recognition judgments with high/low confidence ratings. Right, but not left, ventral PPC activity was observed during the retrieval of these music stimuli. Thus, rather than indicating a special status of left PPC in retrieval, both right and left ventral PPC participate in memory retrieval, depending on the type of information that is to be remembered.

  10. Functional Heterogeneity in Posterior Parietal Cortex Across Attention and Episodic Memory Retrieval

    Science.gov (United States)

    Hutchinson, J. Benjamin; Uncapher, Melina R.; Weiner, Kevin S.; Bressler, David W.; Silver, Michael A.; Preston, Alison R.; Wagner, Anthony D.

    2014-01-01

    While attention is critical for event memory, debate has arisen regarding the extent to which posterior parietal cortex (PPC) activation during episodic retrieval reflects engagement of PPC-mediated mechanisms of attention. Here, we directly examined the relationship between attention and memory, within and across subjects, using functional magnetic resonance imaging attention-mapping and episodic retrieval paradigms. During retrieval, 4 functionally dissociable PPC regions were identified. Specifically, 2 PPC regions positively tracked retrieval outcomes: lateral intraparietal sulcus (latIPS) indexed graded item memory strength, whereas angular gyrus (AnG) tracked recollection. By contrast, 2 other PPC regions demonstrated nonmonotonic relationships with retrieval: superior parietal lobule (SPL) tracked retrieval reaction time, consistent with a graded engagement of top-down attention, whereas temporoparietal junction displayed a complex pattern of below-baseline retrieval activity, perhaps reflecting disengagement of bottom-up attention. Analyses of retrieval effects in PPC topographic spatial attention maps (IPS0-IPS5; SPL1) revealed that IPS5 and SPL1 exhibited a nonmonotonic relationship with retrieval outcomes resembling that in the SPL region, further suggesting that SPL activation during retrieval reflects top-down attention. While demands on PPC attention mechanisms vary during retrieval attempts, the present functional parcellation of PPC indicates that 2 additional mechanisms (mediated by latIPS and AnG) positively track retrieval outcomes. PMID:23019246

  11. Differential contributions of the superior and inferior parietal cortex to feedback versus feedforward control of tools.

    Science.gov (United States)

    Macuga, Kristen L; Frey, Scott H

    2014-05-15

    Damage to the superior and/or inferior parietal lobules (SPL, IPL) (Sirigu et al., 1996) or cerebellum (Grealy and Lee, 2011) can selectively disrupt motor imagery, motivating the hypothesis that these regions participate in predictive (i.e., feedforward) control. If so, then the SPL, IPL, and cerebellum should show greater activity as the demands on feedforward control increase from visually-guided execution (closed-loop) to execution without visual feedback (open-loop) to motor imagery. Using fMRI and a Fitts' reciprocal aiming task with tools directed at targets in far space, we found that the SPL and cerebellum exhibited greater activity during closed-loop control. Conversely, open-loop and imagery conditions were associated with increased activity within the IPL and prefrontal areas. These results are consistent with a superior-to-inferior gradient in the representation of feedback-to-feedforward control within the posterior parietal cortex. Additionally, the anterior SPL displayed greater activity when aiming movements were performed with a stick vs. laser pointer. This may suggest that it is involved in the remapping of far into near (reachable) space (Maravita and Iriki, 2004), or in distalization of the end-effector from hand to stick (Arbib et al., 2009). Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Abnormal prefrontal and parietal activity linked to deficient active binding in working memory in schizophrenia.

    Science.gov (United States)

    Grot, Stéphanie; Légaré, Virginie Petel; Lipp, Olivier; Soulières, Isabelle; Dolcos, Florin; Luck, David

    2017-10-01

    Working memory deficits have been widely reported in schizophrenia, and may result from inefficient binding processes. These processes, and their neural correlates, remain understudied in schizophrenia. Thus, we designed an FMRI study aimed at investigating the neural correlates of both passive and active binding in working memory in schizophrenia. Nineteen patients with schizophrenia and 23 matched controls were recruited to perform a working memory binding task, in which they were instructed to memorize three letters and three spatial locations. In the passive binding condition, letters and spatial locations were directly presented as bound. Conversely, in the active binding condition, words and spatial locations were presented as separated, and participants were instructed to intentionally create associations between them. Patients exhibited a similar performance to the controls for the passive binding condition, but a significantly lower performance for the active binding. FMRI analyses revealed that this active binding deficit was related to aberrant activity in the posterior parietal cortex and the ventrolateral prefrontal cortex. This study provides initial evidence of a specific deficit for actively binding information in schizophrenia, which is linked to dysfunctions in the neural networks underlying attention, manipulation of information, and encoding strategies. Together, our results suggest that all these dysfunctions may be targets for neuromodulation interventions known to improve cognitive deficits in schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Lateralization of the posterior parietal cortex for internal monitoring of self- versus externally generated movements.

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    Ogawa, Kenji; Inui, Toshio

    2007-11-01

    Internal monitoring or state estimation of movements is essential for human motor control to compensate for inherent delays and noise in sensorimotor loops. Two types of internal estimation of movements exist: self-generated movements, and externally generated movements. We used functional magnetic resonance imaging to investigate differences in brain activity for internal monitoring of self- versus externally generated movements during visual occlusion. Participants tracked a sinusoidally moving target with a mouse cursor. On some trials, vision of either target (externally generated) or cursor (self-generated) movement was transiently occluded, during which subjects continued tracking by estimating current position of either the invisible target or cursor on screen. Analysis revealed that both occlusion conditions were associated with increased activity in the presupplementary motor area and decreased activity in the right lateral occipital cortex compared to a control condition with no occlusion. Moreover, the right and left posterior parietal cortex (PPC) showed greater activation during occlusion of target and cursor movements, respectively. This study suggests lateralization of the PPC for internal monitoring of internally versus externally generated movements, fully consistent with previously reported clinical findings.

  14. 10 Hz rTMS over right parietal cortex alters sense of agency during self-controlled movements

    DEFF Research Database (Denmark)

    Ritterband-Rosenbaum, Anina; Karabanov, Anke N; Christensen, Mark Schram

    2014-01-01

    A large body of fMRI and lesion-literature has provided evidence that the Inferior Parietal Cortex (IPC) is important for sensorimotor integration and sense of agency (SoA). We used repetitive transcranial magnetic stimulation (rTMS) to explore the role of the IPC during a validated SoA detection...

  15. Changes in cerebral activations during movement execution and imagery after parietal cortex TMS interleaved with 3T MRI

    NARCIS (Netherlands)

    de Vries, Paulien M.; de Jong, Bauke M.; Bohning, Daryl E.; Walker, John A.; George, Mark S.; Leenders, Klaus L.

    2009-01-01

    The left parietal cortex contributes to goal-directed hand movement. In this study, we targeted this region with transcranial magnetic stimulation (TMS) to assess the effects on a wider distributed circuitry related to motor control. Ten healthy subjects underwent 3 Tesla functional magnetic

  16. Partial clinical response to 2 weeks of 2 Hz repetitive transcranial magnetic stimulation to the right parietal cortex in depression

    NARCIS (Netherlands)

    Schutter, D.J.L.G.; Laman, D.M.; Honk, E.J. van; Vergouwen, A.C.M.; Koerselman, F.

    2009-01-01

    The aim of this treatment study was to evaluate the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) over the right parietal cortex in depression. In a double-blind, sham-controlled design ten consecutive sessions of 2 Hz rTMS (inter-pulse interval 0.5 s) at 90% motor

  17. Amygdala, Pulvinar & Inferior Parietal Cortex Contribute to Early Processing of Faces without Awareness

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    Vanessa eTroiani

    2013-06-01

    Full Text Available The goals of the present study were twofold. First, we wished to investigate the neural correlates of stimulus-driven processing of stimuli strongly suppressed from awareness and in the absence of top-down influences. We accomplished this using a novel approach in which participants performed an orthogonal task atop a flash suppression noise image to prevent top-down search. Second, we wished to investigate the extent to which amygdala responses differentiate between suppressed stimuli (fearful faces and houses based on their motivational relevance. Using continuous flash suppression in conjunction with fMRI, we presented fearful faces, houses, and a no stimulus control to one eye while participants performed an orthogonal task that appeared atop the flashing Mondrian image presented to the opposite eye. In 29 adolescents, we show activation in subcortical regions, including the superior colliculus, amygdala, thalamus, and hippocampus for suppressed objects (fearful faces and houses compared to a no stimulus control. Suppressed stimuli showed less activation compared to a no stimulus control in early visual cortex, indicating that object information was being suppressed from this region. Additionally, we find no activation in regions associated with conscious processing of these percepts (fusiform gyrus and/or parahippocampal cortex as assessed by mean activations and multi-voxel patterns. A psychophysiological interaction analysis that seeded the amygdala showed task-specific (fearful faces greater than houses modulation of right pulvinar and left inferior parietal cortex. Taken together, our results support a role for the amygdala in stimulus-driven attentional guidance towards objects of relevance and a potential mechanism for successful suppression of rivalrous stimuli.

  18. Meta-analysis: how does posterior parietal cortex contribute to reasoning?

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    Wendelken, Carter

    2015-01-01

    Reasoning depends on the contribution of posterior parietal cortex (PPC). But PPC is involved in many basic operations—including spatial attention, mathematical cognition, working memory, long-term memory, and language—and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: (1) reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing; (2) reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC; and (3) reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest (ROI). Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL). Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific to

  19. Meta-analysis: How does posterior parietal cortex contribute to reasoning?

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    Carter eWendelken

    2015-01-01

    Full Text Available Reasoning depends on the contribution of posterior parietal cortex (PPC. But PPC is involved in many basic operations -- including spatial attention, mathematical cognition, working memory, long-term memory, and language -- and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: 1 reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing, 2 reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC, and 3 reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest. Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL. Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific

  20. Increased parietal circuit-breaker activity in delta frequency band and abnormal delta/theta band connectivity in salience network in hyperacusis subjects.

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    Jae Joon Han

    Full Text Available Recent studies have suggested that hyperacusis, an abnormal hypersensitivity to ordinary environmental sounds, may be characterized by certain resting-state cortical oscillatory patterns, even with no sound stimulus. However, previous studies are limited in that most studied subjects with other comorbidities that may have affected cortical activity. In this regard, to assess ongoing cortical oscillatory activity in idiopathic hyperacusis patients with no comorbidities, we compared differences in resting-state cortical oscillatory patterns between five idiopathic hyperacusis subjects and five normal controls. The hyperacusis group demonstrated significantly higher electrical activity in the right auditory-related cortex for the gamma frequency band and left superior parietal lobule (SPL for the delta frequency band versus the control group. The hyperacusis group also showed significantly decreased functional connectivity between the left auditory cortex (AC and left orbitofrontal cortex (OFC, between the left AC and left subgenual anterior cingulate cortex (sgACC for the gamma band, and between the right insula and bilateral dorsal anterior cingulate cortex (dACC and between the left AC and left sgACC for the theta band versus the control group. The higher electrical activity in the SPL may indicate a readiness of "circuit-breaker" activity to shift attention to forthcoming sound stimuli. Also, because of the disrupted salience network, consisting of the dACC and insula, abnormally increased salience to all sound stimuli may emerge, as a consequence of decreased top-down control of the AC by the dACC and dysfunctional emotional weight attached to auditory stimuli by the OFC. Taken together, abnormally enhanced attention and salience to forthcoming sound stimuli may render hyperacusis subjects hyperresponsive to non-noxious auditory stimuli.

  1. Functional specialization of the left ventral parietal cortex in working memory

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    Jennifer Lou Langel

    2014-06-01

    Full Text Available The function of the ventral parietal cortex (VPC is subject to much debate. Many studies suggest a lateralization of function in the VPC, with the left hemisphere facilitating verbal working memory and the right subserving stimulus-driven attention. However, many attentional tasks elicit activity in the VPC bilaterally. To elucidate the potential divides across the VPC in function, we assessed the pattern of activity in the VPC bilaterally across two tasks that require different demands, an oddball attentional task with low working memory demands and a working memory task. An anterior region of the VPC was bilaterally active during novel targets in the oddball task and during retrieval in WM, while more posterior regions of the VPC displayed dissociable functions in the left and right hemisphere, with the left being active during the encoding and retrieval of WM, but not during the oddball task and the right showing the reverse pattern. These results suggest that bilateral regions of the anterior VPC subserve non-mnemonic processes, such as stimulus-driven attention during WM retrieval and oddball detection. The left posterior VPC may be important for speech-related processing important for both working memory and perception, while the right hemisphere is more lateralized for attention.

  2. Virtual lesions of the inferior parietal cortex induce fast changes of implicit religiousness/spirituality.

    Science.gov (United States)

    Crescentini, Cristiano; Aglioti, Salvatore M; Fabbro, Franco; Urgesi, Cosimo

    2014-05-01

    Religiousness and spirituality (RS) are two ubiquitous aspects of human experience typically considered impervious to scientific investigation. Nevertheless, associations between RS and frontoparietal neural activity have been recently reported. However, much less is known about whether such activity is causally involved in modulating RS or just epiphenomenal to them. Here we combined two-pulse (10 Hz) Transcranial Magnetic Stimulation (TMS) with a novel, ad-hoc developed RS-related, Implicit Association Test (IAT) to investigate whether implicit RS representations, although supposedly rather stable, can be rapidly modified by a virtual lesion of inferior parietal lobe (IPL) and dorsolateral prefrontal cortex (DLPFC). A self-esteem (SE) IAT, focused on self-concepts nonrelated to RS representations, was developed as control. A specific increase of RS followed inhibition of IPL demonstrating its causative role in inducing fast plastic changes of religiousness/spirituality. In contrast, DLPFC inhibition had more widespread effects probably reflecting a general role in the acquisition or maintenance of task-rules or in controlling the expression of self-related representations not specific to RS. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Theta, mental flexibility, and post-traumatic stress disorder: connecting in the parietal cortex.

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    Benjamin T Dunkley

    Full Text Available Post-traumatic stress disorder (PTSD is a mental health injury characterised by re-experiencing, avoidance, numbing and hyperarousal. Whilst the aetiology of the disorder is relatively well understood, there is debate about the prevalence of cognitive sequelae that manifest in PTSD. In particular, there are conflicting reports about deficits in executive function and mental flexibility. Even less is known about the neural changes that underlie such deficits. Here, we used magnetoencephalography to study differences in functional connectivity during a mental flexibility task in combat-related PTSD (all males, mean age = 37.4, n = 18 versus a military control (all males, mean age = 33.05, n = 19 group. We observed large-scale increases in theta connectivity in the PTSD group compared to controls. The PTSD group performance was compromised in the more attentionally-demanding task and this was characterised by 'late-stage' theta hyperconnectivity, concentrated in network connections involving right parietal cortex. Furthermore, we observed significant correlations with the connectivity strength in this region with a number of cognitive-behavioural outcomes, including measures of attention, depression and anxiety. These findings suggest atypical coordination of neural synchronisation in large scale networks contributes to deficits in mental flexibility for PTSD populations in timed, attentionally-demanding tasks, and this propensity toward network hyperconnectivity may play a more general role in the cognitive sequelae evident in this disorder.

  4. Parietal cortex integrates contextual and saliency signals during the encoding of natural scenes in working memory.

    Science.gov (United States)

    Santangelo, Valerio; Di Francesco, Simona Arianna; Mastroberardino, Serena; Macaluso, Emiliano

    2015-12-01

    The Brief presentation of a complex scene entails that only a few objects can be selected, processed indepth, and stored in memory. Both low-level sensory salience and high-level context-related factors (e.g., the conceptual match/mismatch between objects and scene context) contribute to this selection process, but how the interplay between these factors affects memory encoding is largely unexplored. Here, during fMRI we presented participants with pictures of everyday scenes. After a short retention interval, participants judged the position of a target object extracted from the initial scene. The target object could be either congruent or incongruent with the context of the scene, and could be located in a region of the image with maximal or minimal salience. Behaviourally, we found a reduced impact of saliency on visuospatial working memory performance when the target was out-of-context. Encoding-related fMRI results showed that context-congruent targets activated dorsoparietal regions, while context-incongruent targets de-activated the ventroparietal cortex. Saliency modulated activity both in dorsal and ventral regions, with larger context-related effects for salient targets. These findings demonstrate the joint contribution of knowledge-based and saliency-driven attention for memory encoding, highlighting a dissociation between dorsal and ventral parietal regions. © 2015 Wiley Periodicals, Inc.

  5. Activity in human visual and parietal cortex reveals object-based attention in working memory.

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    Peters, Benjamin; Kaiser, Jochen; Rahm, Benjamin; Bledowski, Christoph

    2015-02-25

    Visual attention enables observers to select behaviorally relevant information based on spatial locations, features, or objects. Attentional selection is not limited to physically present visual information, but can also operate on internal representations maintained in working memory (WM) in service of higher-order cognition. However, only little is known about whether attention to WM contents follows the same principles as attention to sensory stimuli. To address this question, we investigated in humans whether the typically observed effects of object-based attention in perception are also evident for object-based attentional selection of internal object representations in WM. In full accordance with effects in visual perception, the key behavioral and neuronal characteristics of object-based attention were observed in WM. Specifically, we found that reaction times were shorter when shifting attention to memory positions located on the currently attended object compared with equidistant positions on a different object. Furthermore, functional magnetic resonance imaging and multivariate pattern analysis of visuotopic activity in visual (areas V1-V4) and parietal cortex revealed that directing attention to one position of an object held in WM also enhanced brain activation for other positions on the same object, suggesting that attentional selection in WM activates the entire object. This study demonstrated that all characteristic features of object-based attention are present in WM and thus follows the same principles as in perception. Copyright © 2015 the authors 0270-6474/15/353360-10$15.00/0.

  6. Mental reversal of imagined melodies: a role for the posterior parietal cortex.

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    Zatorre, Robert J; Halpern, Andrea R; Bouffard, Marc

    2010-04-01

    Two fMRI experiments explored the neural substrates of a musical imagery task that required manipulation of the imagined sounds: temporal reversal of a melody. Musicians were presented with the first few notes of a familiar tune (Experiment 1) or its title (Experiment 2), followed by a string of notes that was either an exact or an inexact reversal. The task was to judge whether the second string was correct or not by mentally reversing all its notes, thus requiring both maintenance and manipulation of the represented string. Both experiments showed considerable activation of the superior parietal lobe (intraparietal sulcus) during the reversal process. Ventrolateral and dorsolateral frontal cortices were also activated, consistent with the memory load required during the task. We also found weaker evidence for some activation of right auditory cortex in both studies, congruent with results from previous simpler music imagery tasks. We interpret these results in the context of other mental transformation tasks, such as mental rotation in the visual domain, which are known to recruit the intraparietal sulcus region, and we propose that this region subserves general computations that require transformations of a sensory input. Mental imagery tasks may thus have both task or modality-specific components as well as components that supersede any specific codes and instead represent amodal mental manipulation.

  7. Perception of Upright: Multisensory Convergence and the Role of Temporo-Parietal Cortex

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    Amir Kheradmand

    2017-10-01

    Full Text Available We inherently maintain a stable perception of the world despite frequent changes in the head, eye, and body positions. Such “orientation constancy” is a prerequisite for coherent spatial perception and sensorimotor planning. As a multimodal sensory reference, perception of upright represents neural processes that subserve orientation constancy through integration of sensory information encoding the eye, head, and body positions. Although perception of upright is distinct from perception of body orientation, they share similar neural substrates within the cerebral cortical networks involved in perception of spatial orientation. These cortical networks, mainly within the temporo-parietal junction, are crucial for multisensory processing and integration that generate sensory reference frames for coherent perception of self-position and extrapersonal space transformations. In this review, we focus on these neural mechanisms and discuss (i neurobehavioral aspects of orientation constancy, (ii sensory models that address the neurophysiology underlying perception of upright, and (iii the current evidence for the role of cerebral cortex in perception of upright and orientation constancy, including findings from the neurological disorders that affect cortical function.

  8. The impact of top-down spatial attention on laterality and hemispheric asymmetry in the human parietal cortex.

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    Jeong, Su Keun; Xu, Yaoda

    2016-08-01

    The human parietal cortex exhibits a preference to contralaterally presented visual stimuli (i.e., laterality) as well as an asymmetry between the two hemispheres with the left parietal cortex showing greater laterality than the right. Using visual short-term memory and perceptual tasks and varying target location predictability, this study examined whether hemispheric laterality and asymmetry are fixed characteristics of the human parietal cortex or whether they are dynamic and modulated by the deployment of top-down attention to the target present hemifield. Two parietal regions were examined here that have previously been shown to be involved in visual object individuation and identification and are located in the inferior and superior intraparietal sulcus (IPS), respectively. Across three experiments, significant laterality was found in both parietal regions regardless of attentional modulation with laterality being greater in the inferior than superior IPS, consistent with their roles in object individuation and identification, respectively. Although the deployment of top-down attention had no effect on the superior IPS, it significantly increased laterality in the inferior IPS. The deployment of top-down spatial attention can thus amplify the strength of laterality in the inferior IPS. Hemispheric asymmetry, on the other hand, was absent in both brain regions and only emerged in the inferior but not the superior IPS with the deployment of top-down attention. Interestingly, the strength of hemispheric asymmetry significantly correlated with the strength of laterality in the inferior IPS. Hemispheric asymmetry thus seems to only emerge when there is a sufficient amount of laterality present in a brain region.

  9. Posterior Parietal Cortex and Episodic Encoding: Insights from fMRI Subsequent Memory Effects and Dual Attention Theory

    Science.gov (United States)

    Uncapher, Melina; Wagner, Anthony D.

    2010-01-01

    The formation of episodic memories –– memories for life events –– is affected by attention during event processing. A leading neurobiological model of attention posits two separate yet interacting systems that depend on distinct regions in lateral posterior parietal cortex (PPC). From this dual-attention perspective, dorsal PPC is thought to support the goal-directed allocation of attention, whereas ventral PPC is thought to support reflexive orienting to information that automatically captures attention. To advance understanding of how parietal mechanisms may impact event encoding, we review functional MRI studies that document the relationship between lateral PPC activation during encoding and subsequent memory performance (e.g., later remembering or forgetting). This review reveals that (a) encoding-related activity is frequently observed in human lateral PPC, (b) increased activation in dorsal PPC is associated with later memory success, and (c) increased activation in ventral PPC predominantly correlates with later memory failure. From a dual-attention perspective, these findings suggest that allocating goal-directed attention during event processing increases the probability that the event will be remembered later, whereas the capture of reflexive attention during event processing may have negative consequences for event encoding. The prevalence of encoding-related activation in parietal cortex suggests that neurobiological models of episodic memory should consider how parietal-mediated attentional mechanisms regulate encoding. PMID:19028591

  10. Posterior parietal cortex and episodic encoding: insights from fMRI subsequent memory effects and dual-attention theory.

    Science.gov (United States)

    Uncapher, Melina R; Wagner, Anthony D

    2009-02-01

    The formation of episodic memories--memories for life events--is affected by attention during event processing. A leading neurobiological model of attention posits two separate yet interacting systems that depend on distinct regions in lateral posterior parietal cortex (PPC). From this dual-attention perspective, dorsal PPC is thought to support the goal-directed allocation of attention, whereas ventral PPC is thought to support reflexive orienting to information that automatically captures attention. To advance understanding of how parietal mechanisms may impact event encoding, we review functional MRI studies that document the relationship between lateral PPC activation during encoding and subsequent memory performance (e.g., later remembering or forgetting). This review reveals that (a) encoding-related activity is frequently observed in human lateral PPC, (b) increased activation in dorsal PPC is associated with later memory success, and (c) increased activation in ventral PPC predominantly correlates with later memory failure. From a dual-attention perspective, these findings suggest that allocating goal-directed attention during event processing increases the probability that the event will be remembered later, whereas the capture of reflexive attention during event processing may have negative consequences for event encoding. The prevalence of encoding-related activation in parietal cortex suggests that neurobiological models of episodic memory should consider how parietal-mediated attentional mechanisms regulate encoding.

  11. Right parietal cortex and calculation processing: intraoperative functional mapping of multiplication and addition in patients affected by a brain tumor.

    Science.gov (United States)

    Della Puppa, Alessandro; De Pellegrin, Serena; d'Avella, Elena; Gioffrè, Giorgio; Munari, Marina; Saladini, Marina; Salillas, Elena; Scienza, Renato; Semenza, Carlo

    2013-11-01

    The role of parietal areas in number processing is well known. The significance of intraoperative functional mapping of these areas has been only partially explored, however, and only a few discordant data are available in the surgical literature with regard to the right parietal lobe. The purpose of this study was to evaluate the clinical impact of simple calculation in cortical electrostimulation of right-handed patients affected by a right parietal brain tumor. Calculation mapping in awake surgery was performed in 3 right-handed patients affected by high-grade gliomas located in the right parietal lobe. Preoperatively, none of the patients presented with calculation deficits. In all 3 cases, after sensorimotor and language mapping, cortical and intraparietal sulcus areas involved in single-digit multiplication and addition calculations were mapped using bipolar electrostimulation. In all patients, different sites of the right parietal cortex, mainly in the inferior lobule, were detected as being specifically related to calculation (multiplication or addition). In 2 patients the intraparietal sulcus was functionally specific for multiplication. No functional sites for language were detected. All sites functional for calculation were spared during tumor resection, which was complete in all cases without postoperative neurological deficits. These findings provide intraoperative data in support of an anatomofunctional organization for multiplication and addition within the right parietal area. Furthermore, the study shows the potential clinical relevance of intraoperative mapping of calculation in patients undergoing surgery in the right parietal area. Further and larger studies are needed to confirm these data and assess whether mapped areas are effectively essential for function.

  12. Transcranial direct current stimulation of the posterior parietal cortex modulates arithmetic learning.

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    Grabner, Roland H; Rütsche, Bruno; Ruff, Christian C; Hauser, Tobias U

    2015-07-01

    The successful acquisition of arithmetic skills is an essential step in the development of mathematical competencies and has been associated with neural activity in the left posterior parietal cortex (PPC). It is unclear, however, whether this brain region plays a causal role in arithmetic skill acquisition and whether arithmetic learning can be modulated by means of non-invasive brain stimulation of this key region. In the present study we addressed these questions by applying transcranial direct current stimulation (tDCS) over the left PPC during a short-term training that simulates the typical path of arithmetic skill acquisition (specifically the transition from effortful procedural to memory-based problem-solving strategies). Sixty participants received either anodal, cathodal or sham tDCS while practising complex multiplication and subtraction problems. The stability of the stimulation-induced learning effects was assessed in a follow-up test 24 h after the training. Learning progress was modulated by tDCS. Cathodal tDCS (compared with sham) decreased learning rates during training and resulted in poorer performance which lasted over 24 h after stimulation. Anodal tDCS showed an operation-specific improvement for subtraction learning. Our findings extend previous studies by demonstrating that the left PPC is causally involved in arithmetic learning (and not only in arithmetic performance) and that even a short-term tDCS application can modulate the success of arithmetic knowledge acquisition. Moreover, our finding of operation-specific anodal stimulation effects suggests that the enhancing effects of tDCS on learning can selectively affect just one of several cognitive processes mediated by the stimulated area. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  13. Modulation of motor control in saccadic behaviors by TMS over the posterior parietal cortex.

    Science.gov (United States)

    Liang, Wei-Kuang; Juan, Chi-Hung

    2012-08-01

    The right posterior parietal cortex (rPPC) has been found to be critical in shaping visual selection and distractor-induced saccade curvature in the context of predictive as well as nonpredictive visual cues by means of transcranial magnetic stimulation (TMS) interference. However, the dynamic details of how distractor-induced saccade curvatures are affected by rPPC TMS have not yet been investigated. This study aimed to elucidate the key dynamic properties that cause saccades to curve away from distractors with different degrees of curvature in various TMS and target predictability conditions. Stochastic optimal feedback control theory was used to model the dynamics of the TMS saccade data. This allowed estimation of torques, which was used to identify the critical dynamic mechanisms producing saccade curvature. The critical mechanisms of distractor-induced saccade curvatures were found to be the motor commands and torques in the transverse direction. When an unpredictable saccade target occurred with rPPC TMS, there was an initial period of greater distractor-induced torque toward the side opposite the distractor in the transverse direction, immediately followed by a relatively long period of recovery torque that brought the deviated trace back toward the target. The results imply that the mechanisms of distractor-induced saccade curvature may be comprised of two mechanisms: the first causing the initial deviation and the second bringing the deviated trace back toward the target. The pattern of the initial torque in the transverse direction revealed the former mechanism. Conversely, the later mechanism could be well explained as a consequence of the control policy in this model. To summarize, rPPC TMS increased the initial torque away from the distractor as well as the recovery torque toward the target.

  14. Attention and alcohol cues: a role for medial parietal cortex and shifting away from alcohol features?

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    Thomas Edward Gladwin

    2013-12-01

    Full Text Available Attention plays a central role in theories of alcohol dependence; however, its precise role in alcohol-related biases is not yet clear. In the current study, social drinkers performed a spatial cueing task designed to evoke conflict between automatic processes due to incentive salience and control exerted to follow task-related goals. Such conflict is a potentially important task feature from the perspective of dual-process models of addiction. Subjects received instructions either to direct their attention towards pictures of alcoholic beverages, and away from non-alcohol beverages; or to direct their attention towards pictures of non-alcoholic beverages, and away from alcohol beverages. A probe stimulus was likely to appear at the attended location, so that both spatial and non-spatial interference was possible. Activation in medial parietal cortex was found during Approach Alcohol versus Avoid Alcohol blocks. This region is associated with the, possibly automatic, shifting of attention between stimulus features, suggesting that subjects may have shifted attention away from certain features of alcoholic cues when attention had to be directed towards an upcoming stimulus at their location. Further, activation in voxels close to this region was negatively correlated with riskier drinking behavior. A tentative interpretation of the results is that risky drinking may be associated with a reduced tendency to shift attention away from potentially distracting task-irrelevant alcohol cues. The results suggest novel hypotheses and directions for future study, in particular towards the potential therapeutic use of training the ability to shifting attention away from alcohol-related stimulus features.

  15. Anodal transcranial direct current stimulation of parietal cortex enhances action naming in Corticobasal Syndrome

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    Rosa eManenti

    2015-04-01

    Full Text Available Background: Corticobasal Syndrome (CBS is a neurodegenerative disorder that overlaps both clinically and neuropathologically with Frontotemporal dementia and is characterized by apraxia, alien limb phenomena, cortical sensory loss, cognitive impairment, behavioural changes and aphasia. It has been recently demonstrated that transcranial direct current stimulation (tDCS improves naming in healthy subjects and in subjects with language deficits.Objective: The aim of the present study was to explore the extent to which anodal transcranial direct current stimulation (anodal tDCS over the parietal cortex (PARC could facilitate naming performance in CBS subjects. Methods: Anodal tDCS was applied to the left and right PARC during object and action naming in seventeen patients with a diagnosis of possible CBS. Participants underwent two sessions of anodal tDCS (left and right and one session of placebo tDCS. Vocal responses were recorded and analyzed for accuracy and vocal Reaction Times (vRTs. Results: A shortening of naming latency for actions was observed only after active anodal stimulation over the left PARC, as compared to placebo and right stimulations. No effects have been reported for accuracy.Conclusions: Our preliminary finding demonstrated that tDCS decreased vocal reaction time during action naming in a sample of patients with CBS. A possible explanation of our results is that anodal tDCS over the left PARC effects the brain network implicated in action observation and representation. Further studies, based on larger patient samples, should be conducted to investigate the usefulness of tDCS as an additional treatment of linguistic deficits in CBS patients.

  16. The Importance of Lateral Connections in the Parietal Cortex for Generating Motor Plans.

    Directory of Open Access Journals (Sweden)

    Derrik E Asher

    Full Text Available Substantial evidence has highlighted the significant role of associative brain areas, such as the posterior parietal cortex (PPC in transforming multimodal sensory information into motor plans. However, little is known about how different sensory information, which can have different delays or be absent, combines to produce a motor plan, such as executing a reaching movement. To address these issues, we constructed four biologically plausible network architectures to simulate PPC: 1 feedforward from sensory input to the PPC to a motor output area, 2 feedforward with the addition of an efference copy from the motor area, 3 feedforward with the addition of lateral or recurrent connectivity across PPC neurons, and 4 feedforward plus efference copy, and lateral connections. Using an evolutionary strategy, the connectivity of these network architectures was evolved to execute visually guided movements, where the target stimulus provided visual input for the entirety of each trial. The models were then tested on a memory guided motor task, where the visual target disappeared after a short duration. Sensory input to the neural networks had sensory delays consistent with results from monkey studies. We found that lateral connections within the PPC resulted in smoother movements and were necessary for accurate movements in the absence of visual input. The addition of lateral connections resulted in velocity profiles consistent with those observed in human and non-human primate visually guided studies of reaching, and allowed for smooth, rapid, and accurate movements under all conditions. In contrast, Feedforward or Feedback architectures were insufficient to overcome these challenges. Our results suggest that intrinsic lateral connections are critical for executing accurate, smooth motor plans.

  17. Endogenous BDNF is required for long-term memory formation in the rat parietal cortex.

    Science.gov (United States)

    Alonso, Mariana; Bekinschtein, Pedro; Cammarota, Martín; Vianna, Monica R M; Izquierdo, Iván; Medina, Jorge H

    2005-01-01

    Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory consolidation in the neocortex. Brain-derived neurotrophic factor (BDNF) modulates both short-term synaptic function and activity-dependent synaptic plasticity in hippocampal and cortical neurons. We have recently demonstrated that endogenous BDNF in the hippocampus is involved in memory formation. Here we examined the role of BDNF in the parietal cortex (PCx) in short-term (STM) and long-term memory (LTM) formation of a one-trial fear-motivated learning task in rats. Bilateral infusions of function-blocking anti-BDNF antibody into the PCx impaired both STM and LTM retention scores and decreased the phosphorylation state of cAMP response element-binding protein (CREB). In contrast, intracortical administration of recombinant human BDNF facilitated LTM and increased CREB activation. Moreover, inhibitory avoidance training is associated with a rapid and transient increase in phospho-CREB/total CREB ratio in the PCx. Thus, our results indicate that endogenous BDNF is required for both STM and LTM formation of inhibitory avoidance learning, possibly involving CREB activation-dependent mechanisms. The present data support the idea that early sensory areas constitute important components of the networks subserving memory formation and that information processing in neocortex plays an important role in memory formation.

  18. Neural representation of hand kinematics during prehension in posterior parietal cortex of the macaque monkey.

    Science.gov (United States)

    Chen, Jessie; Reitzen, Shari D; Kohlenstein, Jane B; Gardner, Esther P

    2009-12-01

    Studies of hand manipulation neurons in posterior parietal cortex of monkeys suggest that their spike trains represent objects by the hand postures needed for grasping or by the underlying patterns of muscle activation. To analyze the role of hand kinematics and object properties in a trained prehension task, we correlated the firing rates of neurons in anterior area 5 with hand behaviors as monkeys grasped and lifted knobs of different shapes and locations in the workspace. Trials were divided into four classes depending on the approach trajectory: forward, lateral, and local approaches, and regrasps. The task factors controlled by the animal-how and when he used the hand-appeared to play the principal roles in modulating firing rates of area 5 neurons. In all, 77% of neurons studied (58/75) showed significant effects of approach style on firing rates; 80% of the population responded at higher rates and for longer durations on forward or lateral approaches that included reaching, wrist rotation, and hand preshaping prior to contact, but only 13% distinguished the direction of reach. The higher firing rates in reach trials reflected not only the arm movements needed to direct the hand to the target before contact, but persisted through the contact, grasp, and lift stages. Moreover, the approach style exerted a stronger effect on firing rates than object features, such as shape and location, which were distinguished by half of the population. Forty-three percent of the neurons signaled both the object properties and the hand actions used to acquire them. However, the spread in firing rates evoked by each knob on reach and no-reach trials was greater than distinctions between different objects grasped with the same approach style. Our data provide clear evidence for synergies between reaching and grasping that may facilitate smooth, coordinated actions of the arm and hand.

  19. The organization of the posterior parietal cortex devoted to upper limb actions: An fMRI study

    Science.gov (United States)

    Ferri, Stefania; Rizzolatti, Giacomo

    2015-01-01

    Abstract The present fMRI study examined whether upper‐limb action classes differing in their motor goal are encoded by different PPC sectors. Action observation was used as a proxy for action execution. Subjects viewed actors performing object‐related (e.g., grasping), skin‐displacing (e.g., rubbing the skin), and interpersonal upper limb actions (e.g., pushing someone). Observation of the three action classes activated a three‐level network including occipito‐temporal, parietal, and premotor cortex. The parietal region common to observing all three action classes was located dorsally to the left intraparietal sulcus (DIPSM/DIPSA border). Regions specific for observing an action class were obtained by combining the interaction between observing action classes and stimulus types with exclusive masking for observing the other classes, while for regions considered preferentially active for a class the interaction was exclusively masked with the regions common to all observed actions. Left putative human anterior intraparietal was specific for observing manipulative actions, and left parietal operculum including putative human SII region, specific for observing skin‐displacing actions. Control experiments demonstrated that this latter activation depended on seeing the skin being moved and not simply on seeing touch. Psychophysiological interactions showed that the two specific parietal regions had similar connectivities. Finally, observing interpersonal actions preferentially activated a dorsal sector of left DIPSA, possibly the homologue of ventral intraparietal coding the impingement of the target person's body into the peripersonal space of the actor. These results support the importance of segregation according to the action class as principle of posterior parietal cortex organization for action observation and by implication for action execution. Hum Brain Mapp 36:3845–3866, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley

  20. Collaborative activity between parietal and dorso-lateral prefrontal cortex in dynamic spatial working memory revealed by fMRI.

    Science.gov (United States)

    Diwadkar, V A; Carpenter, P A; Just, M A

    2000-07-01

    Functional MRI was used to determine how the constituents of the cortical network subserving dynamic spatial working memory respond to two types of increases in task complexity. Participants mentally maintained the most recent location of either one or three objects as the three objects moved discretely in either a two- or three-dimensional array. Cortical activation in the dorsolateral prefrontal (DLPFC) and the parietal cortex increased as a function of the number of object locations to be maintained and the dimensionality of the display. An analysis of the response characteristics of the individual voxels showed that a large proportion were activated only when both the variables imposed the higher level of demand. A smaller proportion were activated specifically in response to increases in task demand associated with each of the independent variables. A second experiment revealed the same effect of dimensionality in the parietal cortex when the movement of objects was signaled auditorily rather than visually, indicating that the additional representational demands induced by 3-D space are independent of input modality. The comodulation of activation in the prefrontal and parietal areas by the amount of computational demand suggests that the collaboration between areas is a basic feature underlying much of the functionality of spatial working memory. Copyright 2000 Academic Press.

  1. Normal and abnormal neuronal migration in the developing cerebral cortex.

    Science.gov (United States)

    Sun, Xue-Zhi; Takahashi, Sentaro; Cui, Chun; Zhang, Rui; Sakata-Haga, Hiromi; Sawada, Kazuhiko; Fukui, Yoshihiro

    2002-08-01

    Neuronal migration is the critical cellular process which initiates histogenesis of cerebral cortex. Migration involves a series of complex cell interactions and transformation. After completing their final mitosis, neurons migrate from the ventricular zone into the cortical plate, and then establish neuronal lamina and settle onto the outermost layer, forming an "inside-out" gradient of maturation. This process is guided by radial glial fibers, requires proper receptors, ligands, other unknown extracellular factors, and local signaling to stop neuronal migration. This process is also highly sensitive to various physical, chemical and biological agents as well as to genetic mutations. Any disturbance of the normal process may result in neuronal migration disorder. Such neuronal migration disorder is believed as major cause of both gross brain malformation and more special cerebral structural and functional abnormalities in experimental animals and in humans. An increasing number of instructive studies on experimental models and several genetic model systems of neuronal migration disorder have established the foundation of cortex formation and provided deeper insights into the genetic and molecular mechanisms underlying normal and abnormal neuronal migration.

  2. Clinical evidence of parietal cortex dysfunction and correlation with extent of allodynia in CRPS type 1.

    Science.gov (United States)

    Cohen, H; McCabe, C; Harris, N; Hall, J; Lewis, J; Blake, D R

    2013-04-01

    Unusual symptoms such as digit misidentification and neglect-like phenomena have been reported in complex regional pain syndrome (CRPS), which we hypothesized could be explained by parietal lobe dysfunction. Twenty-two patients with chronic CRPS attending an in-patient rehabilitation programme underwent standard neurological examination followed by clinical assessment of parietal lobe function and detailed sensory testing. Fifteen (68%) patients had evidence of parietal lobe dysfunction. Six (27%) subjects failed six or more test categories and demonstrated new clinical signs consistent with their parietal testing impairments, which were impacting significantly on activities of daily living. A higher incidence was noted in subjects with >1 limb involvement, CRPS affecting the dominant side and in left-handed subjects. Eighteen patients (82%) had mechanical allodynia covering 3-57.5% of the body surface area. Allochiria (unilateral tactile stimulation perceived only in the analogous location on the opposite limb), sensory extinction (concurrent bilateral tactile stimulation perceived only in one limb), referred sensations (unilateral tactile stimulation perceived concurrently in another discrete body area) and dysynchiria (unilateral non-noxious tactile stimulation perceived bilaterally as noxious) were present in some patients. Greater extent of body surface allodynia was correlated with worse parietal function (Spearman's rho = -0.674, p = 0.001). In patients with chronic CRPS, detailed clinical examination may reveal parietal dysfunction, with severity relating to the extent of allodynia. © 2012 European Federation of International Association for the Study of Pain Chapters.

  3. Lower Choline and Myo-Inositol in Temporo-Parietal Cortex Is Associated With Apathy in Amnestic MCI

    Directory of Open Access Journals (Sweden)

    Shankar Tumati

    2018-04-01

    Full Text Available Apathy is a common symptom in patients with amnestic mild cognitive impairment (aMCI and is associated with an increased risk of progression to Alzheimer’s disease (AD. The neural substrates underlying apathy in aMCI may involve multiple brain regions, including the anterior cingulate cortex and the temporo-parietal region. Here we investigated neurometabolites in brain regions that may underlie apathy in aMCI patients using proton magnetic resonance spectroscopy (1H-MRS. Twenty-eight aMCI patients with varying degrees of apathy and 20 matched controls underwent 1H-MRS. Spectra were acquired from single voxels in the posterior cingulate cortex (PCC, dorsal anterior cingulate cortex (DACC, right dorsolateral prefrontal cortex (DLPFC, and right temporo-parietal cortex (TPC. Apathy was measured with the Apathy Evaluation Scale (AES. Spearman partial correlations between metabolite concentrations in each region and severity of apathy were determined. Additionally, analyses of covariance (ANCOVA were performed to determine whether metabolite changes differed between patients with or without clinically-diagnosed apathy. The degree of apathy was found to be negatively correlated with choline and myo-inositol (mI in the TPC. Additional exploratory analyses suggested that N-acetylaspartate (NAA/mI ratio was reduced in aMCI without clinical apathy but not in aMCI with clinical apathy. In the DACC, glutamate and glutamine (Glx levels tended to be higher in the aMCI with apathy group compared to controls and reduced in association with depression scores. In conclusion, apathy in aMCI patients was associated with neurometabolite changes indicative of altered membranal integrity and glial function in the right TPC. Findings also indicated that in a clinically-diagnosed aMCI cohort, apathy symptoms may be suggestive of neural changes that are distinct from aMCI without apathy.

  4. Lower Choline and Myo-Inositol in Temporo-Parietal Cortex Is Associated With Apathy in Amnestic MCI.

    Science.gov (United States)

    Tumati, Shankar; Opmeer, Esther M; Marsman, Jan-Bernard C; Martens, Sander; Reesink, Fransje E; De Deyn, Peter P; Aleman, André

    2018-01-01

    Apathy is a common symptom in patients with amnestic mild cognitive impairment (aMCI) and is associated with an increased risk of progression to Alzheimer's disease (AD). The neural substrates underlying apathy in aMCI may involve multiple brain regions, including the anterior cingulate cortex and the temporo-parietal region. Here we investigated neurometabolites in brain regions that may underlie apathy in aMCI patients using proton magnetic resonance spectroscopy ( 1 H-MRS). Twenty-eight aMCI patients with varying degrees of apathy and 20 matched controls underwent 1 H-MRS. Spectra were acquired from single voxels in the posterior cingulate cortex (PCC), dorsal anterior cingulate cortex (DACC), right dorsolateral prefrontal cortex (DLPFC), and right temporo-parietal cortex (TPC). Apathy was measured with the Apathy Evaluation Scale (AES). Spearman partial correlations between metabolite concentrations in each region and severity of apathy were determined. Additionally, analyses of covariance (ANCOVA) were performed to determine whether metabolite changes differed between patients with or without clinically-diagnosed apathy. The degree of apathy was found to be negatively correlated with choline and myo-inositol (mI) in the TPC. Additional exploratory analyses suggested that N-acetylaspartate (NAA)/mI ratio was reduced in aMCI without clinical apathy but not in aMCI with clinical apathy. In the DACC, glutamate and glutamine (Glx) levels tended to be higher in the aMCI with apathy group compared to controls and reduced in association with depression scores. In conclusion, apathy in aMCI patients was associated with neurometabolite changes indicative of altered membranal integrity and glial function in the right TPC. Findings also indicated that in a clinically-diagnosed aMCI cohort, apathy symptoms may be suggestive of neural changes that are distinct from aMCI without apathy.

  5. Phosphene-guided transcranial magnetic stimulation of occipital but not parietal cortex suppresses stimulus visibility

    Science.gov (United States)

    Tapia, Evelina; Mazzi, Chiara; Savazzi, Silvia; Beck, Diane M.

    2014-01-01

    Transcranial magnetic stimulation (TMS) applied over the occipital lobe approximately 100 ms after the onset of a stimulus decreases its visibility if it appears in the location of the phosphene. Because phosphenes can also be elicited by stimulation of the parietal regions, we asked if the same procedure that is used to reduce visibility of stimuli with occipital TMS will lead to decreased stimulus visibility when TMS is applied to parietal regions. TMS was randomly applied at 0 to 130 ms after the onset of the stimulus (SOA) in steps of 10 ms in occipital and parietal regions. Participants responded to the orientation of the line stimulus and rated its visibility. We replicate previous reports of phosphenes from both occipital and parietal TMS. As previously reported, we also observed visual suppression around the classical 100 ms window both in the objective line orientation and subjective visibility responses with occipital TMS. Parietal stimulation, on the other hand, did not consistently reduce stimulus visibility in any time window. PMID:24584900

  6. Glucose phosphorylation rate in rat parietal cortex during normoglycemia, hypoglycemia, acute hyperglycemia, and in diabetes-prone rats

    Energy Technology Data Exchange (ETDEWEB)

    Broendsted, H.E.; Gjedde, A. (Department of General Physiology and Biophysics, Panum Institute, University of Copenhagen (Denmark))

    1990-01-01

    Cerebral metabolic rate for glucose (CMRglc) was studied in rats using (6-{sup 14}C)glucose. After intravenous injection the radioactivity of the parietal cortex was corrected for loss of labeled CO{sub 2} and divided by the integral of the arterial plasma glucose concentration, determined during tracer circulation. Treatment with insulin, resulting in plasma glucose concentrations less than 2.6 mmol/l, reduced CMRglc to 64% of the values found in control animals. CMRglc did not change in animals with acute hyper-glycemia produced by intraperiotoneal injection of a glucose solution or in diabetes-prone rats with or withour insulin treatment. (author).

  7. Differential roles of polar orbital prefrontal cortex and parietal lobes in logical reasoning with neutral and negative emotional content.

    Science.gov (United States)

    Eimontaite, Iveta; Goel, Vinod; Raymont, Vanessa; Krueger, Frank; Schindler, Igor; Grafman, Jordan

    2018-05-14

    To answer the question of how brain pathology affects reasoning about negative emotional content, we administered a disjunctive logical reasoning task involving arguments with neutral content (e.g. Either there are tigers or women in NYC, but not both; There are no tigers in NYC; There are women in NYC) and emotionally laden content (e.g. Either there are pedophiles or politicians in Texas, but not both; There are politicians in Texas; There are no pedophiles in Texas) to 92 neurological patients with focal lesions to various parts of the brain. A Voxel Lesion Symptom Mapping (VLSM) analysis identified 16 patients, all with lesions to the orbital polar prefrontal cortex (BA 10 & 11), as being selectively impaired in the emotional reasoning condition. Another 17 patients, all with lesions to the parietal cortex, were identified as being impaired in the neutral content condition. The reasoning scores of these two patient groups, along with 23 matched normal controls, underwent additional analysis to explore the effect of belief bias. This analysis revealed that the differences identified above were largely driven by trials where there was an incongruency between the believability of the conclusion and the validity of the argument (i.e. valid argument /false conclusion or invalid argument /true conclusion). Patients with lesions to polar orbital prefrontal cortex underperformed in incongruent emotional content trials and over performed in incongruent neutral content trials (compared to both normal controls and patients with parietal lobe lesions). Patients with lesions to parietal lobes underperformed normal controls (at a trend level) in neutral trials where there was a congruency between the believability of the conclusion and the validity of the argument (i.e. valid argument/true conclusion or invalid argument/false conclusion). We conclude that lesions to the polar orbital prefrontal cortex (i) prevent these patients from enjoying any emotionally induced cognitive

  8. Autoimmune gastritis and parietal cell reactivity in two children with abnormal intestinal permeability

    NARCIS (Netherlands)

    Greenwood, Deanne L. V.; Crock, Patricia; Braye, Stephen; Davidson, Patricia; Sentry, John W.

    Autoimmune gastritis is characterised by lymphocytic infiltration of the gastric submucosa, with loss of parietal and chief cells and achlorhydria. Often, gastritis is expressed clinically as cobalamin deficiency with megaloblastic anaemia, which is generally described as a disease of the elderly.

  9. Interlaminar differences in the pyramidal cell phenotype in parietal cortex of an Indian bat, cynopterus sphinx.

    Science.gov (United States)

    Srivastava, U C; Pathak, S V

    2010-10-30

    To study interlaminar phenotypic variations in the pyramidal neurons of parietal isocortex in bat (Cynopterus sphinx), Golgi and Nissl methods have been employed. The parietal isocortex is relatively thin in the bat as compared to prototheria with layer III, V and VI accounting for more than two—thirds of total cortical thickness. Thick cell free layer I and thinnest accentuated layer II are quite in connotation with other chiropterids. Poor demarcation of layer III/IV in the present study is also in connotation with primitive eutherian mammal (i.e. prototherian) and other chiropterids. Most of the pyramidal cells in the different layers of the parietal isocortex are of typical type as seen in other eutherians but differ significantly in terms of soma shape and size, extent of dendritic arbor, diameter of dendrites and spine density. Percentage of pyramidal neurons, diameter of apical dendrite and spine density on apical dendrite appear to follow an increasing trend from primitive to advanced mammals; but extent of dendrites are probably governed by the specific life patterns of these mammals. It is thus concluded that 'typical' pyramidal neurons in parietal isocortex are similar in therians but different from those in prototherians. It is possible that these cells might have arisen among early eutherians after divergence from prototherian stock.

  10. Posterior parietal cortex is critical for the encoding, consolidation, and retrieval of a memory that guides attention for learning.

    Science.gov (United States)

    Schiffino, Felipe L; Zhou, Vivian; Holland, Peter C

    2014-02-01

    Within most contemporary learning theories, reinforcement prediction error, the difference between the obtained and expected reinforcer value, critically influences associative learning. In some theories, this prediction error determines the momentary effectiveness of the reinforcer itself, such that the same physical event produces more learning when its presentation is surprising than when it is expected. In other theories, prediction error enhances attention to potential cues for that reinforcer by adjusting cue-specific associability parameters, biasing the processing of those stimuli so that they more readily enter into new associations in the future. A unique feature of these latter theories is that such alterations in stimulus associability must be represented in memory in an enduring fashion. Indeed, considerable data indicate that altered associability may be expressed days after its induction. Previous research from our laboratory identified brain circuit elements critical to the enhancement of stimulus associability by the omission of an expected event, and to the subsequent expression of that altered associability in more rapid learning. Here, for the first time, we identified a brain region, the posterior parietal cortex, as a potential site for a memorial representation of altered stimulus associability. In three experiments using rats and a serial prediction task, we found that intact posterior parietal cortex function was essential during the encoding, consolidation, and retrieval of an associability memory enhanced by surprising omissions. We discuss these new results in the context of our previous findings and additional plausible frontoparietal and subcortical networks. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. High-alpha band synchronization across frontal, parietal and visual cortex mediates behavioral and neuronal effects of visuospatial attention.

    Science.gov (United States)

    Lobier, Muriel; Palva, J Matias; Palva, Satu

    2018-01-15

    Visuospatial attention prioritizes processing of attended visual stimuli. It is characterized by lateralized alpha-band (8-14 Hz) amplitude suppression in visual cortex and increased neuronal activity in a network of frontal and parietal areas. It has remained unknown what mechanisms coordinate neuronal processing among frontoparietal network and visual cortices and implement the attention-related modulations of alpha-band amplitudes and behavior. We investigated whether large-scale network synchronization could be such a mechanism. We recorded human cortical activity with magnetoencephalography (MEG) during a visuospatial attention task. We then identified the frequencies and anatomical networks of inter-areal phase synchronization from source localized MEG data. We found that visuospatial attention is associated with robust and sustained long-range synchronization of cortical oscillations exclusively in the high-alpha (10-14 Hz) frequency band. This synchronization connected frontal, parietal and visual regions and was observed concurrently with amplitude suppression of low-alpha (6-9 Hz) band oscillations in visual cortex. Furthermore, stronger high-alpha phase synchronization was associated with decreased reaction times to attended stimuli and larger suppression of alpha-band amplitudes. These results thus show that high-alpha band phase synchronization is functionally significant and could coordinate the neuronal communication underlying the implementation of visuospatial attention. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Automatic and Intentional Number Processing Both Rely on Intact Right Parietal Cortex: A Combined fMRI and Neuronavigated TMS Study

    Science.gov (United States)

    Cohen Kadosh, Roi; Bien, Nina; Sack, Alexander T.

    2012-01-01

    Practice and training usually lead to performance increase in a given task. In addition, a shift from intentional toward more automatic processing mechanisms is often observed. It is currently debated whether automatic and intentional processing is subserved by the same or by different mechanism(s), and whether the same or different regions in the brain are recruited. Previous correlational evidence provided by behavioral, neuroimaging, modeling, and neuropsychological studies addressing this question yielded conflicting results. Here we used transcranial magnetic stimulation (TMS) to compare the causal influence of disrupting either left or right parietal cortex during automatic and intentional numerical processing, as reflected by the size congruity effect and the numerical distance effect, respectively. We found a functional hemispheric asymmetry within parietal cortex with only the TMS-induced right parietal disruption impairing both automatic and intentional numerical processing. In contrast, disrupting the left parietal lobe with TMS, or applying sham stimulation, did not affect performance during automatic or intentional numerical processing. The current results provide causal evidence for the functional relevance of right, but not left, parietal cortex for intentional, and automatic numerical processing, implying that at least within the parietal cortices, automatic, and intentional numerical processing rely on the same underlying hemispheric lateralization. PMID:22347175

  13. Transcranial magnetic stimulation of right inferior parietal cortex causally influences prefrontal activation for visual detection

    DEFF Research Database (Denmark)

    Leitao, Joana; Thielscher, Axel; Lee, Hweeling

    2017-01-01

    -parietal areas integrating the evidence into a decision variable that is compared to a decisional threshold. This concurrent transcranial magnetic stimulation (TMS)-fMRI study applied 10 Hz bursts of four TMS (or Sham) pulses to the intraparietal sulcus (IPS) to investigate the causal influence of IPS...... affect participants' performance accuracy, it affected how observers adjusted their response times after making an error. We therefore suggest that activation increases in superior frontal gyri for misses relative to correct responses may not be critical for signal detection performance, but rather...

  14. Increased gray matter density in the parietal cortex of mathematicians: a voxel-based morphometry study.

    Science.gov (United States)

    Aydin, K; Ucar, A; Oguz, K K; Okur, O O; Agayev, A; Unal, Z; Yilmaz, S; Ozturk, C

    2007-01-01

    The training to acquire or practicing to perform a skill, which may lead to structural changes in the brain, is called experience-dependent structural plasticity. The main purpose of this cross-sectional study was to investigate the presence of experience-dependent structural plasticity in mathematicians' brains, which may develop after long-term practice of mathematic thinking. Twenty-six volunteer mathematicians, who have been working as academicians, were enrolled in the study. We applied an optimized method of voxel-based morphometry in the mathematicians and the age- and sex-matched control subjects. We assessed the gray and white matter density differences in mathematicians and the control subjects. Moreover, the correlation between the cortical density and the time spent as an academician was investigated. We found that cortical gray matter density in the left inferior frontal and bilateral inferior parietal lobules of the mathematicians were significantly increased compared with the control subjects. Furthermore, increase in gray matter density in the right inferior parietal lobule of the mathematicians was strongly correlated with the time spent as an academician (r = 0.84; P mathematicians' brains revealed increased gray matter density in the cortical regions related to mathematic thinking. The correlation between cortical density increase and the time spent as an academician suggests experience-dependent structural plasticity in mathematicians' brains.

  15. Seeing without the Occipito-Parietal Cortex: Simultagnosia as a Shrinkage of the Attentional Visual Field

    Directory of Open Access Journals (Sweden)

    François Michel

    2004-01-01

    Full Text Available Following bi-parietal lesions patient AT showed a severe inability to relocate her attention within a visual field which perimetry proved to be near-normal. An experimental approach with tasks testing visuo-spatial attention demonstrated a shrinkage of A.T.’s attentional visual field. With her visual attention narrowed to a kind of functional tunnel vision, the patient exhibited simultanagnosia (Wolpert, 1924, a symptom previously described in 1909 by Balint under the label of Psychic paralysis of “Gaze”. In striking contrast AT showed an efficient and effortless perception of complex natural scenes, which, according to recent work in normal subjects, necessitate few if any attentional resources.

  16. Distinct contribution of the parietal and temporal cortex to hand configuration and contextual judgements about tools.

    Science.gov (United States)

    Andres, Michael; Pelgrims, Barbara; Olivier, Etienne

    2013-09-01

    Neuropsychological studies showed that manipulatory and semantic knowledge can be independently impaired in patients with upper-limb apraxia, leading to different tool use disorders. The present study aimed to dissociate the brain regions involved in judging the hand configuration or the context associated to tool use. We focussed on the left supramarginalis gyrus (SMG) and left middle temporal gyrus (MTG), whose activation, as evidenced by functional magnetic resonance imaging (fMRI) studies, suggests that they may play a critical role in tool use. The distinctive location of SMG in the dorsal visual stream led us to postulate that this parietal region could play a role in processing incoming information about tools to shape hand posture. In contrast, we hypothesized that MTG, because of its interconnections with several cortical areas involved in semantic memory, could contribute to retrieving semantic information necessary to create a contextual representation of tool use. To test these hypotheses, we used neuronavigated transcranial magnetic stimulation (TMS) to interfere transiently with the function of either left SMG or left MTG in healthy participants performing judgement tasks about either hand configuration or context of tool use. We found that SMG virtual lesions impaired hand configuration but not contextual judgements, whereas MTG lesions selectively interfered with judgements about the context of tool use while leaving hand configuration judgements unaffected. This double dissociation demonstrates that the ability to infer a context of use or a hand posture from tool perception relies on distinct processes, performed in the temporal and parietal regions. The present findings suggest that tool use disorders caused by SMG lesions will be characterized by difficulties in selecting the appropriate hand posture for tool use, whereas MTG lesions will yield difficulties in using tools in the appropriate context. Copyright © 2012. Published by Elsevier Ltd.

  17. Activity in inferior parietal and medial prefrontal cortex signals the accumulation of evidence in a probability learning task.

    Directory of Open Access Journals (Sweden)

    Mathieu d'Acremont

    Full Text Available In an uncertain environment, probabilities are key to predicting future events and making adaptive choices. However, little is known about how humans learn such probabilities and where and how they are encoded in the brain, especially when they concern more than two outcomes. During functional magnetic resonance imaging (fMRI, young adults learned the probabilities of uncertain stimuli through repetitive sampling. Stimuli represented payoffs and participants had to predict their occurrence to maximize their earnings. Choices indicated loss and risk aversion but unbiased estimation of probabilities. BOLD response in medial prefrontal cortex and angular gyri increased linearly with the probability of the currently observed stimulus, untainted by its value. Connectivity analyses during rest and task revealed that these regions belonged to the default mode network. The activation of past outcomes in memory is evoked as a possible mechanism to explain the engagement of the default mode network in probability learning. A BOLD response relating to value was detected only at decision time, mainly in striatum. It is concluded that activity in inferior parietal and medial prefrontal cortex reflects the amount of evidence accumulated in favor of competing and uncertain outcomes.

  18. Low-frequency rTMS in the superior parietal cortex affects the working memory in horizontal axis during the spatial task performance.

    Science.gov (United States)

    Ribeiro, Jéssica Alves; Marinho, Francisco Victor Costa; Rocha, Kaline; Magalhães, Francisco; Baptista, Abrahão Fontes; Velasques, Bruna; Ribeiro, Pedro; Cagy, Mauricio; Bastos, Victor Hugo; Gupta, Daya; Teixeira, Silmar

    2018-03-01

    Spatial working memory has been extensively investigated with different tasks, treatments, and analysis tools. Several studies suggest that low frequency of the repetitive transcranial magnetic stimulation (rTMS) applied to the parietal cortex may influence spatial working memory (SWM). However, it is not yet known if after low-frequency rTMS applied to the superior parietal cortex, according to Pz electroencephalography (EEG) electrode, would change the orientation interpretation about the vertical and horizontal axes coordinates in an SWM task. The current study aims at filling this gap and obtains a better understanding of the low-frequency rTMS effect in SWM. In this crossover study, we select 20 healthy subjects in two conditions (control and 1-Hz rTMS). The subjects performed an SWM task with two random coordinates. Our results presented that low-frequency rTMS applied over the superior parietal cortex may influence the SWM to lead to a larger distance of axes interception point (p low-frequency rTMS over the superior parietal cortex (SPC) changes the SWM performance, and it has more predominance in horizontal axis.

  19. Excitatory stimulation of the right inferior parietal cortex lessens implicit religiousness/spirituality.

    Science.gov (United States)

    Crescentini, Cristiano; Di Bucchianico, Marilena; Fabbro, Franco; Urgesi, Cosimo

    2015-04-01

    Although religiousness and spirituality (RS) are considered two fundamental constituents of human life, neuroscientific investigation has long avoided the study of their neurocognitive basis. Nevertheless, recent investigations with brain imaging and brain damaged patients, and more recently with brain stimulation methods, have documented important associations between RS beliefs and experiences and frontoparietal neural activity. In this study, we further investigated how individuals' implicit RS self-representations can be modulated by changes in right inferior parietal lobe (IPL) excitability, a key region associated to RS. To this end, we combined continuous theta burst stimulation (cTBS), intermittent TBS (iTBS), and sham TBS with RS-related, Implicit Association Test (IAT) and with a control self-esteem (SE) IAT in a group of fourteen healthy adult individuals. A specific decrease of implicit RS, as measured with the IAT effect, was induced by increasing IPL excitability with iTBS; conversely cTBS, which is supposedly inhibitory, left participants' implicit RS unchanged. The performance in the control SE-IAT was left unchanged by any TBS stimulation. These data showed the causative role of right IPL functional state in mediating plastic changes of implicit RS. Implications of these results are also discussed in the light of the variability of behavioral effects associated with TBS. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Temporal structure in neuronal activity during working memory in Macaque parietal cortex

    CERN Document Server

    Pesaran, B; Sahami, M; Mitra, P; Andersen, R A

    2000-01-01

    A number of cortical structures are reported to have elevated single unit firing rates sustained throughout the memory period of a working memory task. How the nervous system forms and maintains these memories is unknown but reverberating neuronal network activity is thought to be important. We studied the temporal structure of single unit (SU) activity and simultaneously recorded local field potential (LFP) activity from area LIP in the inferior parietal lobe of two awake macaques during a memory-saccade task. Using multitaper techniques for spectral analysis, which play an important role in obtaining the present results, we find elevations in spectral power in a 50--90 Hz (gamma) frequency band during the memory period in both SU and LFP activity. The activity is tuned to the direction of the saccade providing evidence for temporal structure that codes for movement plans during working memory. We also find SU and LFP activity are coherent during the memory period in the 50--90 Hz gamma band and no consisten...

  1. Functional connectivity between prefrontal and parietal cortex drives visuo-spatial attention shifts.

    Science.gov (United States)

    Heinen, Klaartje; Feredoes, Eva; Ruff, Christian C; Driver, Jon

    2017-05-01

    It is well established that the frontal eye-fields (FEF) in the dorsal attention network (DAN) guide top-down selective attention. In addition, converging evidence implies a causal role for the FEF in attention shifting, which is also known to recruit the ventral attention network (VAN) and fronto-striatal regions. To investigate the causal influence of the FEF as (part of) a central hub between these networks, we applied thetaburst transcranial magnetic stimulation (TBS) off-line, combined with functional magnetic resonance (fMRI) during a cued visuo-spatial attention shifting paradigm. We found that TBS over the right FEF impaired performance on a visual discrimination task in both hemifields following attention shifts, while only left hemifield performance was affected when participants were cued to maintain the focus of attention. These effects recovered ca. 20min post stimulation. Furthermore, particularly following attention shifts, TBS suppressed the neural signal in bilateral FEF, right inferior and superior parietal lobule (IPL/SPL) and bilateral supramarginal gyri (SMG). Immediately post stimulation, functional connectivity was impaired between right FEF and right SMG as well as right putamen. Importantly, the extent of decreased connectivity between right FEF and right SMG correlated with behavioural impairment following attention shifts. The main finding of this study demonstrates that influences from right FEF on SMG in the ventral attention network causally underly attention shifts, presumably by enabling disengagement from the current focus of attention. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Reward value-based gain control: divisive normalization in parietal cortex.

    Science.gov (United States)

    Louie, Kenway; Grattan, Lauren E; Glimcher, Paul W

    2011-07-20

    The representation of value is a critical component of decision making. Rational choice theory assumes that options are assigned absolute values, independent of the value or existence of other alternatives. However, context-dependent choice behavior in both animals and humans violates this assumption, suggesting that biological decision processes rely on comparative evaluation. Here we show that neurons in the monkey lateral intraparietal cortex encode a relative form of saccadic value, explicitly dependent on the values of the other available alternatives. Analogous to extra-classical receptive field effects in visual cortex, this relative representation incorporates target values outside the response field and is observed in both stimulus-driven activity and baseline firing rates. This context-dependent modulation is precisely described by divisive normalization, indicating that this standard form of sensory gain control may be a general mechanism of cortical computation. Such normalization in decision circuits effectively implements an adaptive gain control for value coding and provides a possible mechanistic basis for behavioral context-dependent violations of rationality.

  3. Parietal operculum and motor cortex activities predict motor recovery in moderate to severe stroke

    Directory of Open Access Journals (Sweden)

    Firdaus Fabrice Hannanu

    2017-01-01

    In subacute stroke, fMRI brain activity related to passive movement measured in a sensorimotor network defined by activity during voluntary movement predicted motor recovery better than baseline motor-FMS alone. Furthermore, fMRI sensorimotor network activity measures considered alone allowed excellent clinical recovery prediction and may provide reliable biomarkers for assessing new therapies in clinical trial contexts. Our findings suggest that neural reorganization related to motor recovery from moderate to severe stroke results from balanced changes in ipsilesional MI (BA4a and a set of phylogenetically more archaic sensorimotor regions in the ventral sensorimotor trend, in which OP1 and OP4 processes may complement the ipsilesional dorsal motor cortex in achieving compensatory sensorimotor recovery.

  4. Dissociable contribution of the parietal and frontal cortex to coding movement direction and amplitude

    Directory of Open Access Journals (Sweden)

    Marco eDavare

    2015-05-01

    Full Text Available To reach for an object, we must convert its spatial location into an appropriate motor command, merging movement direction and amplitude. In humans, it has been suggested that this visuo-motor transformation occurs in a dorsomedial parieto-frontal pathway, although the causal contribution of the areas constituting the reaching circuit remains unknown. Here we used transcranial magnetic stimulation (TMS in healthy volunteers to disrupt the function of either the medial intraparietal area (mIPS or dorsal premotor cortex (PMd, in each hemisphere. The task consisted in performing step-tracking movements with the right wrist towards targets located in different directions and eccentricities; the targets were either visible for the whole trial (Target-ON or flashed for 200 ms (Target-OFF. Left and right mIPS disruption led to errors in the initial direction of movements performed towards contralateral targets. These errors were corrected online in the Target-ON condition but when the target was flashed for 200 ms, mIPS TMS manifested as a larger endpoint spreading. In contrast, left PMd virtual lesions led to higher acceleration and velocity peaks - two parameters typically used to probe the planned movement amplitude - irrespective of the target position, hemifield and presentation condition; in the Target-OFF condition, left PMd TMS induced overshooting and increased the endpoint dispersion along the axis of the target direction. These results indicate that left PMd intervenes in coding amplitude during movement preparation. The critical TMS timings leading to errors in direction and amplitude were different, namely 160-100 ms before movement onset for mIPS and 100-40 ms for left PMd. TMS applied over right PMd had no significant effect. These results indicate that, during motor preparation, direction and amplitude of goal-directed movements are processed by different cortical areas, at distinct timings, and according to a specific hemispheric

  5. 10 Hz rTMS over right parietal cortex alters sense of agency during self-generated movements

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    Anina eRitterband-Rosenbaum

    2014-06-01

    Full Text Available A large body of fMRI and lesion-literature has provided evidence that the Inferior Parietal Cortex (IPC is important for sensorimotor integration and sense of agency (SoA. We used repetitive transcranial magnetic stimulation (rTMS to explore the role of the IPC during a validated SoA detection task. 12 healthy, right-handed adults were included. The effects of rTMS on subjects’ SoA during self-generated movements were explored. The experiment consisted of 1/3 self-generated movements and 2/3 computer manipulated movements that introduced uncertainty as to whether the subjects were agents of an observed movement. Subjects completed three sessions, in which subjects received online rTMS over the right IPC (active condition, over the vertex (CZ (sham condition or no TMS but a sound-matched control. We found that rTMS over right IPC significantly altered SoA of the non-perturbed movements. Following IPC stimulation subjects were more likely to experience self-generated movements as being externally perturbed compared to the control site (P=0.002 and the stimulation-free control (P=0.042. The data support the importance of IPC activation during sensorimotor comparison in order to correctly determine the agent of movements.

  6. Disturbance of visual search by stimulating to posterior parietal cortex in the brain using transcranial magnetic stimulation

    Science.gov (United States)

    Iramina, Keiji; Ge, Sheng; Hyodo, Akira; Hayami, Takehito; Ueno, Shoogo

    2009-04-01

    In this study, we applied a transcranial magnetic stimulation (TMS) to investigate the temporal aspect for the functional processing of visual attention. Although it has been known that right posterior parietal cortex (PPC) in the brain has a role in certain visual search tasks, there is little knowledge about the temporal aspect of this area. Three visual search tasks that have different difficulties of task execution individually were carried out. These three visual search tasks are the "easy feature task," the "hard feature task," and the "conjunction task." To investigate the temporal aspect of the PPC involved in the visual search, we applied various stimulus onset asynchronies (SOAs) and measured the reaction time of the visual search. The magnetic stimulation was applied on the right PPC or the left PPC by the figure-eight coil. The results show that the reaction times of the hard feature task are longer than those of the easy feature task. When SOA=150 ms, compared with no-TMS condition, there was a significant increase in target-present reaction time when TMS pulses were applied. We considered that the right PPC was involved in the visual search at about SOA=150 ms after visual stimulus presentation. The magnetic stimulation to the right PPC disturbed the processing of the visual search. However, the magnetic stimulation to the left PPC gives no effect on the processing of the visual search.

  7. Normal and abnormal neuronal migration in the developing cerebral cortex

    OpenAIRE

    Sun, Xue-Zhi; Takahashi, Sentaro; Cui, Chun; Zhang, Rui; Sakata-Haga, Hiromi; Sawada, Kazuhiko; Fukui, Yoshihiro

    2002-01-01

    Neuronal migration is the critical cellular process which initiates histogenesis of cerebral cortex. Migration involves a series of complex cell interactions and transformation. After completing their final mitosis, neurons migrate from the ventricular zone into the cortical plate, and then establish neuronal lamina and settle onto the outermost layer, forming an “inside-out” gradient of maturation. This process is guided by radial glial fibers, requires proper receptors, ligands, other unkno...

  8. Relationship between cortex and pulvinar abnormalities on diffusion-weighted imaging in status epilepticus.

    Science.gov (United States)

    Nakae, Yoshiharu; Kudo, Yosuke; Yamamoto, Ryoo; Dobashi, Yuichi; Kawabata, Yuichi; Ikeda, Shingo; Yokoyama, Mutsumi; Higashiyama, Yuichi; Doi, Hiroshi; Johkura, Ken; Tanaka, Fumiaki

    2016-01-01

    The aim of this study was to analyze the pattern of magnetic resonance diffusion-weighted imaging (DWI) findings in status epilepticus in terms of clinical characteristics. Participants comprised 106 patients with status epilepticus who were admitted to our hospital and underwent DWI. Forty-five patients (42.5 %) showed abnormal findings on DWI and were divided into two groups, comprising 26 patients (24.5 %) with cortex lesions alone and 19 patients (17.9 %) with cortex and pulvinar lesions in the same hemisphere. A long duration of status epilepticus (>120 min) tended to be more prevalent among patients with cortex and pulvinar lesions (57.9 %) than among patients with cortex lesions alone (30.8 %) by univariate and multivariate analyses. Todd's palsy tended to be more frequent in patients with abnormalities on DWI (24/45, 53.3 %) than in patients with normal DWI (21/61, 34.4 %). Six of the 26 patients with cortex lesions alone (23.1 %) had taken anti-epileptic drugs before the attack compared to none of the 19 patients with both cortex and pulvinar lesions. The trend toward a longer duration of status epilepticus in patients with both cortex and pulvinar lesions favors a spreading pattern of seizure discharge from cortex to pulvinar via cortico-pulvinar pathways, and anti-epileptic drugs might, to some extent, prevent spreading of seizure discharge from cortex to pulvinar. In addition, existence of high-intensity areas on DWI at the onset of epilepsy may be a predictive factor for the occurrence of Todd's palsy.

  9. Abnormal activation of the primary somatosensory cortex in spasmodic dysphonia: an fMRI study.

    Science.gov (United States)

    Simonyan, Kristina; Ludlow, Christy L

    2010-11-01

    Spasmodic dysphonia (SD) is a task-specific focal dystonia of unknown pathophysiology, characterized by involuntary spasms in the laryngeal muscles during speaking. Our aim was to identify symptom-specific functional brain activation abnormalities in adductor spasmodic dysphonia (ADSD) and abductor spasmodic dysphonia (ABSD). Both SD groups showed increased activation extent in the primary sensorimotor cortex, insula, and superior temporal gyrus during symptomatic and asymptomatic tasks and decreased activation extent in the basal ganglia, thalamus, and cerebellum during asymptomatic tasks. Increased activation intensity in SD patients was found only in the primary somatosensory cortex during symptomatic voice production, which showed a tendency for correlation with ADSD symptoms. Both SD groups had lower correlation of activation intensities between the primary motor and sensory cortices and additional correlations between the basal ganglia, thalamus, and cerebellum during symptomatic and asymptomatic tasks. Compared with ADSD patients, ABSD patients had larger activation extent in the primary sensorimotor cortex and ventral thalamus during symptomatic task and in the inferior temporal cortex and cerebellum during symptomatic and asymptomatic voice production. The primary somatosensory cortex shows consistent abnormalities in activation extent, intensity, correlation with other brain regions, and symptom severity in SD patients and, therefore, may be involved in the pathophysiology of SD.

  10. Basal ganglia impairments in autism spectrum disorder are related to abnormal signal gating to prefrontal cortex.

    Science.gov (United States)

    Prat, Chantel S; Stocco, Andrea; Neuhaus, Emily; Kleinhans, Natalia M

    2016-10-01

    Research on the biological basis of autism spectrum disorder has yielded a list of brain abnormalities that are arguably as diverse as the set of behavioral symptoms that characterize the disorder. Among these are patterns of abnormal cortical connectivity and abnormal basal ganglia development. In attempts to integrate the existing literature, the current paper tests the hypothesis that impairments in the basal ganglia's function to flexibly select and route task-relevant neural signals to the prefrontal cortex underpins patterns of abnormal synchronization between the prefrontal cortex and other cortical processing centers observed in individuals with autism spectrum disorder (ASD). We tested this hypothesis using a Dynamic Causal Modeling analysis of neuroimaging data collected from 16 individuals with ASD (mean age=25.3 years; 6 female) and 17 age- and IQ-matched neurotypical controls (mean age=25.6, 6 female), who performed a Go/No-Go test of executive functioning. Consistent with the hypothesis tested, a random-effects Bayesian model selection procedure determined that a model of network connectivity in which basal ganglia activation modulated connectivity between the prefrontal cortex and other key cortical processing centers best fit the data of both neurotypicals and individuals with ASD. Follow-up analyses suggested that the largest group differences were observed for modulation of connectivity between prefrontal cortex and the sensory input region in the occipital lobe [t(31)=2.03, p=0.025]. Specifically, basal ganglia activation was associated with a small decrease in synchronization between the occipital region and prefrontal cortical regions in controls; however, in individuals with ASD, basal ganglia activation resulted in increased synchronization between the occipital region and the prefrontal cortex. We propose that this increased synchronization may reflect a failure in basal ganglia signal gating mechanisms, resulting in a non-selective copying

  11. Abnormal anatomical connectivity between the amygdala and orbitofrontal cortex in conduct disorder.

    Directory of Open Access Journals (Sweden)

    Luca Passamonti

    Full Text Available Previous research suggested that structural and functional abnormalities within the amygdala and orbitofrontal cortex contribute to the pathophysiology of Conduct Disorder (CD. Here, we investigated whether the integrity of the white-matter pathways connecting these regions is abnormal and thus may represent a putative neurobiological marker for CD.Diffusion Tensor Imaging (DTI was used to investigate white-matter microstructural integrity in male adolescents with childhood-onset CD, compared with healthy controls matched in age, sex, intelligence, and socioeconomic status. Two approaches were employed to analyze DTI data: voxel-based morphometry of fractional anisotropy (FA, an index of white-matter integrity, and virtual dissection of white-matter pathways using tractography.Adolescents with CD displayed higher FA within the right external capsule relative to controls (T = 6.08, P<0.05, Family-Wise Error, whole-brain correction. Tractography analyses showed that FA values within the uncinate fascicle (connecting the amygdala and orbitofrontal cortex were abnormally increased in individuals with CD relative to controls. This was in contrast with the inferior frontal-occipital fascicle, which showed no significant group differences in FA. The finding of increased FA in the uncinate fascicle remained significant when factoring out the contribution of attention-deficit/hyperactivity disorder symptoms. There were no group differences in the number of streamlines in either of these anatomical tracts.These results provide evidence that CD is associated with white-matter microstructural abnormalities in the anatomical tract that connects the amygdala and orbitofrontal cortex, the uncinate fascicle. These results implicate abnormal maturation of white-matter pathways which are fundamental in the regulation of emotional behavior in CD.

  12. Posterior parietal cortex role in a sensorimotor task performance Papel do córtex parietal posterior na realização de uma tarefa sensório-motora

    Directory of Open Access Journals (Sweden)

    Sergio Nader

    2008-06-01

    Full Text Available This study aimed to elucidate electrophysiological and cortical mechanisms involved in anticipatory actions when individuals had to catch balls in free drop; specifically through quantitative electroencephalography (qEEG alpha absolute power changes. The sample was composed for 23 health subjects, both sexes, with ages varying between 25 and 40 years, absence of mental and physical illness, right handed and don't make use of any psychoactive or psychotropic substance at the time of the study. The experiment consisted of a task of catching balls in free drop. The three-way ANOVA analysis demonstrated an interaction between moment and position factors in left parietal posterior cortex (PPC (p=0.001. Through the experimental task employed, this area demonstrated a differentiated activity involving expectation, planning and preparedness in the ball's drop task.O estudo tentou elucidar mecanismos eletrofisiológicos e corticais envolvidos em ações antecipatórias quando os sujeitos testados tiveram que apreender bolas em queda livre; especificamente através de mudanças na potência absoluta na banda alfa da eletrencefalografia quantitativa (EEGq. A amostra foi composta por 23 sujeitos sadios, ambos os sexos, idade entre variando entre 25 e 40 anos, sem comprometimento físico e mental, destros, e não fazer uso de nenhuma substância psicoativa ou psicotrópicos até o momento do estudo. O experimento consistiu de uma tarefa de apreensão de bolas em queda livre. A análise three-way ANOVA demonstrou uma interação entre os fatores momento e posição no córtex parietal posterior (CPP esquerdo (p=0,001. Através da tarefa experimental empregada, esta área demonstrou uma atividade diferenciada envolvendo expectativa, planejamento e prontidão na tarefa de queda de bolas.

  13. Abnormal prefrontal cortex resting state functional connectivity and severity of internet gaming disorder.

    Science.gov (United States)

    Jin, Chenwang; Zhang, Ting; Cai, Chenxi; Bi, Yanzhi; Li, Yangding; Yu, Dahua; Zhang, Ming; Yuan, Kai

    2016-09-01

    Internet Gaming Disorder (IGD) among adolescents has become an important public concern and gained more and more attention internationally. Recent studies focused on IGD and revealed brain abnormalities in the IGD group, especially the prefrontal cortex (PFC). However, the role of PFC-striatal circuits in pathology of IGD remains unknown. Twenty-five adolescents with IGD and 21 age- and gender-matched healthy controls were recruited in our study. Voxel-based morphometric (VBM) and functional connectivity analysis were employed to investigate the abnormal structural and resting-state properties of several frontal regions in individuals with online gaming addiction. Relative to healthy comparison subjects, IGD subjects showed significant decreased gray matter volume in PFC regions including the bilateral dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC) and the right supplementary motor area (SMA) after controlling for age and gender effects. We chose these regions as the seeding areas for the resting-state analysis and found that IGD subjects showed decreased functional connectivity between several cortical regions and our seeds, including the insula, and temporal and occipital cortices. Moreover, significant decreased functional connectivity between some important subcortical regions, i.e., dorsal striatum, pallidum, and thalamus, and our seeds were found in the IGD group and some of those changes were associated with the severity of IGD. Our results revealed the involvement of several PFC regions and related PFC-striatal circuits in the process of IGD and suggested IGD may share similar neural mechanisms with substance dependence at the circuit level.

  14. Abnormal excitability and episodic low-frequency oscillations in the cerebral cortex of the tottering mouse.

    Science.gov (United States)

    Cramer, Samuel W; Popa, Laurentiu S; Carter, Russell E; Chen, Gang; Ebner, Timothy J

    2015-04-08

    The Ca(2+) channelopathies caused by mutations of the CACNA1A gene that encodes the pore-forming subunit of the human Cav2.1 (P/Q-type) voltage-gated Ca(2+) channel include episodic ataxia type 2 (EA2). Although, in EA2 the emphasis has been on cerebellar dysfunction, patients also exhibit episodic, nonmotoric abnormalities involving the cerebral cortex. This study demonstrates episodic, low-frequency oscillations (LFOs) throughout the cerebral cortex of tottering (tg/tg) mice, a widely used model of EA2. Ranging between 0.035 and 0.11 Hz, the LFOs in tg/tg mice can spontaneously develop very high power, referred to as a high-power state. The LFOs in tg/tg mice are mediated in part by neuronal activity as tetrodotoxin decreases the oscillations and cortical neuron discharge contain the same low frequencies. The high-power state involves compensatory mechanisms because acutely decreasing P/Q-type Ca(2+) channel function in either wild-type (WT) or tg/tg mice does not induce the high-power state. In contrast, blocking l-type Ca(2+) channels, known to be upregulated in tg/tg mice, reduces the high-power state. Intriguingly, basal excitatory glutamatergic neurotransmission constrains the high-power state because blocking ionotropic or metabotropic glutamate receptors results in high-power LFOs in tg/tg but not WT mice. The high-power LFOs are decreased markedly by acetazolamide and 4-aminopyridine, the primary treatments for EA2, suggesting disease relevance. Together, these results demonstrate that the high-power LFOs in the tg/tg cerebral cortex represent a highly abnormal excitability state that may underlie noncerebellar symptoms that characterize CACNA1A mutations. Copyright © 2015 the authors 0270-6474/15/355664-16$15.00/0.

  15. Maternal Sevoflurane Exposure Causes Abnormal Development of Fetal Prefrontal Cortex and Induces Cognitive Dysfunction in Offspring

    Directory of Open Access Journals (Sweden)

    Ruixue Song

    2017-01-01

    Full Text Available Maternal sevoflurane exposure during pregnancy is associated with increased risk for behavioral deficits in offspring. Several studies indicated that neurogenesis abnormality may be responsible for the sevoflurane-induced neurotoxicity, but the concrete impact of sevoflurane on fetal brain development remains poorly understood. We aimed to investigate whether maternal sevoflurane exposure caused learning and memory impairment in offspring through inducing abnormal development of the fetal prefrontal cortex (PFC. Pregnant mice at gestational day 15.5 received 2.5% sevoflurane for 6 h. Learning function of the offspring was evaluated with the Morris water maze test at postnatal day 30. Brain tissues of fetal mice were subjected to immunofluorescence staining to assess differentiation, proliferation, and cell cycle dynamics of the fetal PFC. We found that maternal sevoflurane anesthesia impaired learning ability in offspring through inhibiting deep-layer immature neuron output and neuronal progenitor replication. With the assessment of cell cycle dynamics, we established that these effects were mediated through cell cycle arrest in neural progenitors. Our research has provided insights into the cell cycle-related mechanisms by which maternal sevoflurane exposure can induce neurodevelopmental abnormalities and learning dysfunction and appeals people to consider the neurotoxicity of anesthetics when considering the benefits and risks of nonobstetric surgical procedures.

  16. Sparse coding can predict primary visual cortex receptive field changes induced by abnormal visual input.

    Science.gov (United States)

    Hunt, Jonathan J; Dayan, Peter; Goodhill, Geoffrey J

    2013-01-01

    Receptive fields acquired through unsupervised learning of sparse representations of natural scenes have similar properties to primary visual cortex (V1) simple cell receptive fields. However, what drives in vivo development of receptive fields remains controversial. The strongest evidence for the importance of sensory experience in visual development comes from receptive field changes in animals reared with abnormal visual input. However, most sparse coding accounts have considered only normal visual input and the development of monocular receptive fields. Here, we applied three sparse coding models to binocular receptive field development across six abnormal rearing conditions. In every condition, the changes in receptive field properties previously observed experimentally were matched to a similar and highly faithful degree by all the models, suggesting that early sensory development can indeed be understood in terms of an impetus towards sparsity. As previously predicted in the literature, we found that asymmetries in inter-ocular correlation across orientations lead to orientation-specific binocular receptive fields. Finally we used our models to design a novel stimulus that, if present during rearing, is predicted by the sparsity principle to lead robustly to radically abnormal receptive fields.

  17. Abnormal ventral tegmental area-anterior cingulate cortex connectivity in Parkinson's disease with depression.

    Science.gov (United States)

    Wei, Luqing; Hu, Xiao; Yuan, Yonggui; Liu, Weiguo; Chen, Hong

    2018-07-16

    Neuropathology suggests that Parkinson's disease (PD) with depression may involve a progressive degeneration of the nigrostriatal and mesocorticolimbic dopaminergic systems. Previous positron emission tomography (PET) and single-photon emission computed tomography (SPECT) studies have shown that dopamine changes in individual brain regions constituting the nigrostriatal and mesocorticolimbic circuits are associated with depression in PD. However, few studies have been conducted on the circuit-level alterations in this disease. The present study used resting-state fMRI and seed-based functional connectivity of putative dopaminergic midbrain regions (i.e., substantia nigra (SN) and ventral tegmental area (VTA)) to investigate the circuit-related abnormalities in PD with depression. The results showed that depressed PD (DPD) patients relative to healthy controls (HC) and non-depressed PD (NDPD) patients had increased functional connectivity between VTA and anterior cingulate cortex (ACC), demonstrating that dysfunctional mesocorticolimbic dopaminergic neurotransmission may be associated with depression in PD. Compared with HC, DPD and NDPD patients showed increased functional connectivity from SN to sensorimotor cortex, validating that alterations in the nigrostriatal circuitry could be responsible for cardinal motor features in PD. In addition, aberrant connectivity between VTA and ACC was correlated with the severity of depression in PD patients, further supporting that abnormal mesocorticolimbic system may account for depressive symptoms in PD. These results have provided potential circuit-level biomarkers of depression in PD, and suggested that resting state functional connectivity of midbrain dopaminergic nuclei may be useful for understanding the underlying pathology in PD with depression. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Gamma-radiation produces abnormal Bergmann fibers and ectopic granule cells in mouse cerebellar cortex

    International Nuclear Information System (INIS)

    Inouye, Minoru; Hayasaka, Shizu; Funahashi, Atsushi; Yamamura, Hideki

    1992-01-01

    Morphological changes in Bergmann glial fibers in the developing cerebellar cortex produced by exposure to gamma-rays were investigated in association with ectopic granule cells. Six-day-old mice that had been exposed to 3 Gy of gamma-radiation were killed 6 hours after exposure or at 7 through 30 days of age. Their cerebella were examined histologically and immunohistochemically for glial fibrillary acidic protein in Bergmann fibers. Extensive cell death took place in the external granular layer (EGL) of the cerebellum from 6 through 24 hours after exposure. This led to the thinning of the EGL and a decrease in the number of migrating cells in the molecular layer. The number of Bergmann cells was not decreased, but the fibers in the molecular layer were distorted; whereas, in the control these fibers were straight and perpendicular to the pial surface. The EGL began to recover 2 days after exposure, and abnormally oriented migrating cells were seen. At 17 days of age, some cell clustering was observed in the molecular layer of the irradiated cerebellum. Distortion of the Bergmann fibers was marked in regions where ectopic granule cells appeared at 30 days of age. These findings suggest that the distortion of Bergmann fibers leads to the production of ectopic granule cells after exposure to gamma-radiation. (author)

  19. Abnormal motor cortex excitability during linguistic tasks in adductor-type spasmodic dysphonia.

    Science.gov (United States)

    Suppa, A; Marsili, L; Giovannelli, F; Di Stasio, F; Rocchi, L; Upadhyay, N; Ruoppolo, G; Cincotta, M; Berardelli, A

    2015-08-01

    In healthy subjects (HS), transcranial magnetic stimulation (TMS) applied during 'linguistic' tasks discloses excitability changes in the dominant hemisphere primary motor cortex (M1). We investigated 'linguistic' task-related cortical excitability modulation in patients with adductor-type spasmodic dysphonia (ASD), a speech-related focal dystonia. We studied 10 ASD patients and 10 HS. Speech examination included voice cepstral analysis. We investigated the dominant/non-dominant M1 excitability at baseline, during 'linguistic' (reading aloud/silent reading/producing simple phonation) and 'non-linguistic' tasks (looking at non-letter strings/producing oral movements). Motor evoked potentials (MEPs) were recorded from the contralateral hand muscles. We measured the cortical silent period (CSP) length and tested MEPs in HS and patients performing the 'linguistic' tasks with different voice intensities. We also examined MEPs in HS and ASD during hand-related 'action-verb' observation. Patients were studied under and not-under botulinum neurotoxin-type A (BoNT-A). In HS, TMS over the dominant M1 elicited larger MEPs during 'reading aloud' than during the other 'linguistic'/'non-linguistic' tasks. Conversely, in ASD, TMS over the dominant M1 elicited increased-amplitude MEPs during 'reading aloud' and 'syllabic phonation' tasks. CSP length was shorter in ASD than in HS and remained unchanged in both groups performing 'linguistic'/'non-linguistic' tasks. In HS and ASD, 'linguistic' task-related excitability changes were present regardless of the different voice intensities. During hand-related 'action-verb' observation, MEPs decreased in HS, whereas in ASD they increased. In ASD, BoNT-A improved speech, as demonstrated by cepstral analysis and restored the TMS abnormalities. ASD reflects dominant hemisphere excitability changes related to 'linguistic' tasks; BoNT-A returns these excitability changes to normal. © 2015 Federation of European Neuroscience Societies and John

  20. Temporal abnormalities in children with developmental dyscalculia.

    Science.gov (United States)

    Vicario, Carmelo Mario; Rappo, Gaetano; Pepi, Annamaria; Pavan, Andrea; Martino, Davide

    2012-01-01

    Recent imaging studies have associated Developmental dyscalculia (DD) to structural and functional alterations corresponding Parietal and the Prefrontal cortex (PFC). Since these areas were shown also to be involved in timing abilities, we hypothesized that time processing is abnormal in DD. We compared time processing abilities between 10 children with pure DD (8 years old) and 11 age-matched healthy children. Results show that the DD group underestimated duration of a sub-second scale when asked to perform a time comparison task. The timing abnormality observed in our DD participants is consistent with evidence of a shared fronto-parietal neural network for representing time and quantity.

  1. Abnormal retinoid and TrkB signaling in the prefrontal cortex in mood disorders

    NARCIS (Netherlands)

    Qi, Xin-Rui; Zhao, Juan; Liu, Ji; Fang, Hui; Swaab, Dick F; Zhou, Jiang-Ning

    The prefrontal cortex shows structural and functional alterations in mood disorders. Retinoid signaling, brain-derived neurotrophic factor (BDNF), and its receptor TrkB are reported to be involved in depression. Here, we found that mRNA levels of key elements of retinoid signaling were significantly

  2. Abnormal Amygdala and Prefrontal Cortex Activation to Facial Expressions in Pediatric Bipolar Disorder

    Science.gov (United States)

    Garrett, Amy S.; Reiss, Allan L.; Howe, Meghan E.; Kelley, Ryan G.; Singh, Manpreet K.; Adleman, Nancy E.; Karchemskiy, Asya; Chang, Kiki D.

    2012-01-01

    Objective: Previous functional magnetic resonance imaging (fMRI) studies in pediatric bipolar disorder (BD) have reported greater amygdala and less dorsolateral prefrontal cortex (DLPFC) activation to facial expressions compared to healthy controls. The current study investigates whether these differences are associated with the early or late…

  3. Cerebellar cortex development in the weaver condition presents regional and age-dependent abnormalities without differences in Purkinje cells neurogenesis.

    Science.gov (United States)

    Martí, Joaquín; Santa-Cruz, María C; Hervás, José P; Bayer, Shirley A; Villegas, Sandra

    2016-01-01

    Ataxias are neurological disorders associated with the degeneration of Purkinje cells (PCs). Homozygous weaver mice (wv/wv) have been proposed as a model for hereditary cerebellar ataxia because they present motor abnormalities and PC loss. To ascertain the physiopathology of the weaver condition, the development of the cerebellar cortex lobes was examined at postnatal day (P): P8, P20 and P90. Three approaches were used: 1) quantitative determination of several cerebellar features; 2) qualitative evaluation of the developmental changes occurring in the cortical lobes; and 3) autoradiographic analyses of PC generation and placement. Our results revealed a reduction in the size of the wv/wv cerebellum as a whole, confirming previous results. However, as distinguished from these reports, we observed that quantified parameters contribute differently to the abnormal growth of the wv/wv cerebellar lobes. Qualitative analysis showed anomalies in wv/wv cerebellar cytoarchitecture, depending on the age and lobe analyzed. Such abnormalities included the presence of the external granular layer after P20 and, at P90, ectopic cells located in the molecular layer following several placement patterns. Finally, we obtained autoradiographic evidence that wild-type and wv/wv PCs presented similar neurogenetic timetables, as reported. However, the innovative character of this current work lies in the fact that the neurogenetic gradients of wv/wv PCs were not modified from P8 to P90. A tendency for the accumulation of late-formed PCs in the anterior and posterior lobes was found, whereas early-generated PCs were concentrated in the central and inferior lobes. These data suggested that wv/wv PCs may migrate properly to their final destinations. The extrapolation of our results to patients affected with cerebellar ataxias suggests that all cerebellar cortex lobes are affected with several age-dependent alterations in cytoarchitectonics. We also propose that PC loss may be regionally

  4. Anatomic abnormalities of the anterior cingulate cortex before psychosis onset: an MRI study of ultra-high-risk individuals.

    Science.gov (United States)

    Fornito, Alex; Yung, Alison R; Wood, Stephen J; Phillips, Lisa J; Nelson, Barnaby; Cotton, Sue; Velakoulis, Dennis; McGorry, Patrick D; Pantelis, Christos; Yücel, Murat

    2008-11-01

    Abnormalities of the anterior cingulate cortex (ACC) are frequently implicated in the pathophysiology of psychotic disorders, but whether such changes are apparent before psychosis onset remains unclear. In this study, we characterized prepsychotic ACC abnormalities in a sample of individuals at ultra-high-risk (UHR) for psychosis. Participants underwent baseline magnetic resonance imaging and were followed-up over 12-24 months to ascertain diagnostic outcomes. Baseline ACC morphometry was then compared between UHR individuals who developed psychosis (UHR-P; n = 35), those who did not (UHR-NP; n = 35), and healthy control subjects (n = 33). Relative to control subjects, UHR-P individuals displayed bilateral thinning of a rostral paralimbic ACC region that was negatively correlated with negative symptoms, whereas UHR-NP individuals displayed a relative thickening of dorsal and rostral limbic areas that was correlated with anxiety ratings. Baseline ACC differences between the two UHR groups predicted time to psychosis onset, independently of symptomatology. Subdiagnostic comparisons revealed that changes in the UHR-P group were driven by individuals subsequently diagnosed with a schizophrenia spectrum psychosis. These findings indicate that anatomic abnormalities of the ACC precede psychosis onset and that baseline ACC differences distinguish between UHR individuals who do and do not subsequently develop frank psychosis. They also indicate that prepsychotic changes are relatively specific to individuals who develop a schizophrenia spectrum disorder, suggesting they may represent a diagnostically specific risk marker.

  5. Reduced parietal activation in cervical dystonia after parietal TMS interleaved with fMRI

    NARCIS (Netherlands)

    de Vries, Paulien M.; de Jong, Bauke M.; Bohning, Daryl E.; Hinson, Vanessa K.; George, Mark S.; Leenders, Klaus L.

    Objective: Clinically normal hand movement with altered cerebral activation patterns in cervical dystonia (CD) may imply cerebral adaptation. Since impaired sensorimotor integration appears to play a role in dystonia, left superior parietal cortex modulation with repetitive transcranial magnetic

  6. Abnormal functional activation and maturation of ventromedial prefrontal cortex and cerebellum during temporal discounting in autism spectrum disorder.

    Science.gov (United States)

    Murphy, Clodagh M; Christakou, Anastasia; Giampietro, Vincent; Brammer, Michael; Daly, Eileen M; Ecker, Christine; Johnston, Patrick; Spain, Debbie; Robertson, Dene M; Murphy, Declan G; Rubia, Katya

    2017-11-01

    People with autism spectrum disorder (ASD) have poor decision-making and temporal foresight. This may adversely impact on their everyday life, mental health, and productivity. However, the neural substrates underlying poor choice behavior in people with ASD, or its' neurofunctional development from childhood to adulthood, are unknown. Despite evidence of atypical structural brain development in ASD, investigation of functional brain maturation in people with ASD is lacking. This cross-sectional developmental fMRI study investigated the neural substrates underlying performance on a temporal discounting (TD) task in 38 healthy (11-35 years old) male adolescents and adults with ASD and 40 age, sex, and IQ-matched typically developing healthy controls. Most importantly, we assessed group differences in the neurofunctional maturation of TD across childhood and adulthood. Males with ASD had significantly poorer task performance and significantly lower brain activation in typical regions that mediate TD for delayed choices, in predominantly right hemispheric regions of ventrolateral/dorsolateral prefrontal cortices, ventromedial prefrontal cortex, striatolimbic regions, and cerebellum. Importantly, differential activation in ventromedial frontal cortex and cerebellum was associated with abnormal functional brain maturation; controls, in contrast to people with ASD, showed progressively increasing activation with increasing age in these regions; which furthermore was associated with performance measures and clinical ASD measures (stereotyped/restricted interests). Findings provide first cross-sectional evidence that reduced activation of TD mediating brain regions in people with ASD during TD is associated with abnormal functional brain development in these regions between childhood and adulthood, and this is related to poor task performance and clinical measures of ASD. Hum Brain Mapp 38:5343-5355, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. T174. STRUCTURAL ABNORMALITIES IN THE CINGULATE CORTEX IN ADOLESCENTS AT ULTRA-HIGH RISK WHO LATER DEVELOP PSYCHOSIS

    Science.gov (United States)

    Fortea, Adriana; van Eindhjoven, Phillip; Pariente, Jose; Calvo, Anna; Batalla, Albert; de la Serna, Elena; Ilzarbe, Daniel; Tor, Jordina; Dolz, Montserrat; Baeza, Inmaculada; Sugranyes, Gisela

    2018-01-01

    Abstract Background Identification of biomarkers of transition to psychosis in individuals at ultra-high risk (UHR) has the potential to improve future outcomes (McGorry, 2008). Structural MRI studies with UHR samples have revealed steeper rates of cortical thinning in temporal, prefrontal and cingulate cortices in individuals who later develop psychosis in both baseline and longitudinal comparisons (Fusar-Poli, 2011; Cannon, 2014). However, little is known about how onset of prodromal symptoms during adolescence impacts on changes in cortical thickness (CTH) (Ziermans, 2012). Methods Multicentre cross-sectional case-control study, including youth aged 10–17 years, recruited from two child and adolescent mental health centres. UHR individuals were identified using the Structured Interview for Prodromal Syndromes criteria with some modifications. Healthy controls (HC) were recruited from the same geographical area. Exclusion criteria comprised personal history of psychotic symptoms, IQ.6) for CTH measures. Images were pre-processed employing automated procedures implemented in FreeSurfer 5.3.0, cortical parcellation employed the Desikan-Killiany brain atlas. Analyses: First, mean global and lobar (frontal, parietal, temporal, occipital, insula and cingulate) CTH measurements were computed. Then, within lobes showing group effects, CTH was measured for each parcellation. ANCOVA was performed to test differences between groups in SPSS 22.0, including gender, age, total intracranial volume and site as covariates. Significance was set at p<.05, corrected using the false discovery rate (FDR). Results 122 subjects were included (59 UHR-NP vs. 18 UHR-P vs. 45 HC, mean ages: 15.2 ± 1.5 vs. 15.0 ± 1.8 vs. 15.8 ± 1.5, F=1.9, p=.15; gender (%female): 61.0% vs 61.1% vs 68.9%, χ2=.76, p=.68). There were no significant differences in case-control proportion between centres: χ2=1.3, p=.25. No significant differences in global CTH in UHR-P (2.57 ± 0.13mm) relative to UHR

  8. [Neuroanatomy of the Parietal Association Areas].

    Science.gov (United States)

    Kobayashi, Yasushi

    2016-11-01

    The parietal association cortex comprises the superior and inferior parietal lobules, the precuneus and the cortices in the intraparietal, parietooccipital and lunate sulci. By processing somatic, visual, acoustic and vestibular sensory information, the parietal association cortex plays a pivotal role in spatial cognition and motor control of the eyes and the extremities. Sensory information from the primary and secondary somatosensory areas enters the superior parietal lobule and is transferred to the inferior parietal lobule. Visual information is processed through the dorsal visual pathway and it reaches the inferior parietal lobule, the intraparietal sulcus and the precuneus. Acoustic information is transferred posteriorly from the primary acoustic area, and it reaches the posterior region of the inferior parietal lobule. The areas in the intraparietal sulcus project to the premotor area, the frontal eye fields, and the prefrontal area. These areas are involved in the control of ocular movements, reaching and grasping of the upper extremities, and spatial working memory. The posterior region of the inferior parietal lobule and the precuneus both project either directly, or indirectly via the posterior cingulate gyrus, to the parahippocampal and entorhinal cortices. Both these areas are strongly associated with hippocampal functions for long-term memory formation.

  9. Purine-related metabolites and their converting enzymes are altered in frontal, parietal and temporal cortex at early stages of Alzheimer's disease pathology.

    Science.gov (United States)

    Alonso-Andrés, Patricia; Albasanz, José Luis; Ferrer, Isidro; Martín, Mairena

    2018-01-24

    Adenosine, hypoxanthine, xanthine, guanosine and inosine levels were assessed by HPLC, and the activity of related enzymes 5'-nucleotidase (5'-NT), adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) measured in frontal (FC), parietal (PC) and temporal (TC) cortices at different stages of disease progression in Alzheimer's disease (AD) and in age-matched controls. Significantly decreased levels of adenosine, guanosine, hypoxanthine and xanthine, and apparently less inosine, are found in FC from the early stages of AD; PC and TC show an opposing pattern, as adenosine, guanosine and inosine are significantly increased at least at determinate stages of AD whereas hypoxanthine and xanthine levels remain unaltered. 5'-NT is reduced in membranes and cytosol in FC mainly at early stages but not in PC, and only at advanced stages in cytosol in TC. ADA activity is decreased in AD when considered as a whole but increased at early stages in TC. Finally, PNP activity is increased only in TC at early stages. Purine metabolism alterations occur at early stages of AD independently of neurofibrillary tangles and β-amyloid plaques. Alterations are stage dependent and region dependent, the latter showing opposite patterns in FC compared with PC and TC. Adenosine is the most affected of the assessed purines. © 2018 International Society of Neuropathology.

  10. Cognitive control dysfunction and abnormal frontal cortex activation in stimulant drug users and their biological siblings.

    Science.gov (United States)

    Smith, D G; Jones, P S; Bullmore, E T; Robbins, T W; Ersche, K D

    2013-05-14

    Cognitive and neural abnormalities are known to accompany chronic drug abuse, with impairments in cognition and changes in cortical structure seen in stimulant-dependent individuals. However, premorbid differences have also been observed in the brains and behavior of individuals at risk for substance abuse, before they develop dependence. Endophenotype research has emerged as a useful method for assessing preclinical traits that may be risk factors for pathology by studying patient populations and their undiagnosed first-degree relatives. This study used the color-word Stroop task to assess executive functioning in stimulant-dependent individuals, their unaffected biological siblings and unrelated healthy control volunteers using a functional magnetic resonance imaging paradigm. Both the stimulant-dependent and sibling participants demonstrated impairments in cognitive control and processing speed on the task, registering significantly longer response latencies. However, the two groups generated very different neural responses, with the sibling participants exhibiting a significant decrease in activation in the inferior frontal gyrus compared with both stimulant-dependent individuals and control participants. Both target groups also demonstrated a decrease in hemispheric laterality throughout the task, exhibiting a disproportionate increase in right hemispheric activation, which was associated with their behavioral inefficiencies. These findings not only suggest a possible risk factor for stimulant abuse of poor inhibitory control and cortical inefficiency but they also demonstrate possible adaptations in the brains of stimulant users.

  11. Abnormal functional connectivity of the medial cortex in euthymic bipolar II disorder.

    Science.gov (United States)

    Marchand, William R; Lee, James N; Johnson, Susanna; Gale, Phillip; Thatcher, John

    2014-06-03

    This project utilized functional MRI (fMRI) and a motor activation paradigm to investigate neural circuitry in euthymic bipolar II disorder. We hypothesized that circuitry involving the cortical midline structures (CMS) would demonstrate abnormal functional connectivity. Nineteen subjects with recurrent bipolar disorder and 18 controls were studied using fMRI and a motor activation paradigm. We used functional connectivity analyses to identify circuits with aberrant connectivity. We found increased functional connectivity among bipolar subjects compared to healthy controls in two CMS circuits. One circuit included the medial aspect of the left superior frontal gyrus and the dorsolateral region of the left superior frontal gyrus. The other included the medial aspect of the right superior frontal gyrus, the dorsolateral region of the left superior frontal gyrus and the right medial frontal gyrus and surrounding region. Our results indicate that CMS circuit dysfunction persists in the euthymic state and thus may represent trait pathology. Future studies should address whether these circuits contribute to relapse of illness. Our results also suggest the possibility that aberrations of superior frontal circuitry may impact default mode network and cognitive processes. Published by Elsevier Inc.

  12. Overlapping Parietal Activity in Memory and Perception: Evidence for the Attention to Memory Model

    Science.gov (United States)

    Cabeza, Roberto; Mazuz, Yonatan S.; Stokes, Jared; Kragel, James E.; Woldorff, Marty G.; Ciaramelli, Elisa; Olson, Ingrid R.; Moscovitch, Morris

    2011-01-01

    The specific role of different parietal regions to episodic retrieval is a topic of intense debate. According to the Attention to Memory (AtoM) model, dorsal parietal cortex (DPC) mediates top-down attention processes guided by retrieval goals, whereas ventral parietal cortex (VPC) mediates bottom-up attention processes captured by the retrieval…

  13. Near-Infrared Spectroscopy Reveals Abnormal Hemodynamics in the Left Dorsolateral Prefrontal Cortex of Menopausal Depression Patients

    Directory of Open Access Journals (Sweden)

    Xiang-Yun Ma

    2017-01-01

    Full Text Available Background/Objective. Menopausal depression (MD is characterized by depressive symptoms along with hormonal fluctuations. We investigate brain function alteration between major depressive disorder (MDD and MD. Methods. The difference in oxygenated hemoglobin (Oxy-Hb for the prefrontal cortex (PFC was compared retrospectively among 90 females presented with 30 MDD, 30 MD, and 30 healthy controls (HCs using verbal fluency task (VFT with near-infrared spectroscopy (NIRS. Results. We observed a significant difference in Oxy-Hb alteration in the left dorsolateral PFC (DLPFC using VFT with NIRS (channel 18, P=0.007 between the MD and MDD groups. A significant difference in Oxy-Hb levels was observed among the three groups in the bilateral DLPFC (channels 18, 27, 33, 39, 41, and 45; P<0.05. Compared to the HCs, the MD group presented lower Oxy-Hb activation in the right DLPFC (channel 41; P=0.048 and the left DLPFC (channels 18, 39, and 45; P<0.05, and the MDD group presented lower Oxy-Hb activation in the right DLPFC (channels 27, 33, and 41; P<0.05 and the left DLPFC (channels 39 and 45; P<0.05. Conclusion. Abnormal hemodynamics of the left DLPFC can differentiate MD from MDD by NIRS.

  14. Abnormal asymmetry of white matter tracts between ventral posterior cingulate cortex and middle temporal gyrus in recent-onset schizophrenia.

    Science.gov (United States)

    Joo, Sung Woo; Chon, Myong-Wuk; Rathi, Yogesh; Shenton, Martha E; Kubicki, Marek; Lee, Jungsun

    2018-02-01

    Previous studies have reported abnormalities in the ventral posterior cingulate cortex (vPCC) and middle temporal gyrus (MTG) in schizophrenia patients. However, it remains unclear whether the white matter tracts connecting these structures are impaired in schizophrenia. Our study investigated the integrity of these white matter tracts (vPCC-MTG tract) and their asymmetry (left versus right side) in patients with recent onset schizophrenia. Forty-seven patients and 24 age-and sex-matched healthy controls were enrolled in this study. We extracted left and right vPCC-MTG tract on each side from T1W and diffusion MRI (dMRI) at 3T. We then calculated the asymmetry index of diffusion measures of vPCC-MTG tracts as well as volume and thickness of vPCC and MTG using the formula: 2×(right-left)/(right+left). We compared asymmetry indices between patients and controls and evaluated their correlations with the severity of psychiatric symptoms and cognition in patients using the Positive and Negative Syndrome Scale (PANSS), video-based social cognition scale (VISC) and the Wechsler Adult Intelligence Scale (WAIS-III). Asymmetry of fractional anisotropy (FA) and radial diffusivity (RD) in the vPCC-MTG tract, while present in healthy controls, was not evident in schizophrenia patients. Also, we observed that patients, not healthy controls, had a significant FA decrease and RD increase in the left vPCC-MTG tract. There was no significant association between the asymmetry indices of dMRI measures and IQ, VISC, or PANSS scores in schizophrenia. Disruption of asymmetry of the vPCC-MTG tract in schizophrenia may contribute to the pathophysiology of schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Abnormal Parietal Function in Conversion Paresis

    NARCIS (Netherlands)

    van Beilen, Marije; de Jong, Bauke M.; Gieteling, Esther W.; Renken, Remco; Leenders, Klaus L.

    2011-01-01

    The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study

  16. Downstream targets of methyl CpG binding protein 2 and their abnormal expression in the frontal cortex of the human Rett syndrome brain

    Directory of Open Access Journals (Sweden)

    Minchenko Dimitri

    2010-04-01

    Full Text Available Abstract Background The Rett Syndrome (RTT brain displays regional histopathology and volumetric reduction, with frontal cortex showing such abnormalities, whereas the occipital cortex is relatively less affected. Results Using microarrays and quantitative PCR, the mRNA expression profiles of these two neuroanatomical regions were compared in postmortem brain tissue from RTT patients and normal controls. A subset of genes was differentially expressed in the frontal cortex of RTT brains, some of which are known to be associated with neurological disorders (clusterin and cytochrome c oxidase subunit 1 or are involved in synaptic vesicle cycling (dynamin 1. RNAi-mediated knockdown of MeCP2 in vitro, followed by further expression analysis demonstrated that the same direction of abnormal expression was recapitulated with MeCP2 knockdown, which for cytochrome c oxidase subunit 1 was associated with a functional respiratory chain defect. Chromatin immunoprecipitation (ChIP analysis showed that MeCP2 associated with the promoter regions of some of these genes suggesting that loss of MeCP2 function may be responsible for their overexpression. Conclusions This study has shed more light on the subset of aberrantly expressed genes that result from MECP2 mutations. The mitochondrion has long been implicated in the pathogenesis of RTT, however it has not been at the forefront of RTT research interest since the discovery of MECP2 mutations. The functional consequence of the underexpression of cytochrome c oxidase subunit 1 indicates that this is an area that should be revisited.

  17. Abnormal Concentration of GABA and Glutamate in The Prefrontal Cortex in Schizophrenia.-An in Vivo 1H-MRS Study.

    Science.gov (United States)

    Chen, Tianyi; Wang, Yingchan; Zhang, Jianye; Wang, Zuowei; Xu, Jiale; Li, Yao; Yang, Zhilei; Liu, Dengtang

    2017-10-25

    The etiology and pathomechanism of schizophrenia are unknown. The traditional dopamine (DA) hypothesis is unable to fully explain its pathology and therapeutics. The glutamate (Glu) and γ-aminobutyric acid (GABA) hypotheses suggest Glu or GABA concentrations are abnormal in the brains of patients with schizophrenia. Magnetic resonance spectroscopy (MRS) show glutamate level increases in the ventromedial prefrontal cortex (vmPFC) including the anterior cingulated cortex (ACC) in those with schizophrenia. To investigate the function of the glutamate system (glutamate and γ-aminobutyric acid) in the etiology and pathomechanism of schizophrenia. 24 drug naïve patients with schizophrenia and 24 healthy volunteers were matched by gender, age, and educational level. The Siemens 3T MRI system was used to collect the magnetic resonance spectroscopy (MRS) data of the subjects. The regions of interest included the left dorsolateral prefrontal cortex (IDLPFC), ventromedial prefrontal cortex (vmPFC), and anterior cingulate cortex (ACC). LCModel software was used to analyze the concentrations of γ-aminobutyric acid (GABA), glutamate (Glu), glutamine (Gln), N-acetylaspartate (NAA), and N-acetylaspartylglutamate (NAAG) in the region of interest. Meanwhile, the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression Scale (CGI) were used to assess the mental symptoms and severity of the disease. The median GABA concentrations in the anterior cingulate cortex of the schizophrenia group and the healthy control group were 1.90 (Q1=1.55, Q3=2.09) and 2.16 (Q1=1.87, Q3=2.59) respectively; the mean (sd) Glu concentrations were 6.07 (2.48) and 6.54 (1.99); the median Gln concentrations were 0.36 (Q1=0.00, Q3=0.74) and 0.29 (Q1=0.00, Q3=0.59); the between-group difference of the GABA concentrations was statistically significant ( Z =-2.95, p =0.003); the between-group difference of the GABA/(NAA+NAAG) was statistically significant ( Z =-2.72, p =0.012); the

  18. Bold-functional MRI study of the abnormal cortex and the relationship between the inpairment of vision and the decreased activation of the visual cortex in anisometropic amblyopia

    International Nuclear Information System (INIS)

    Wang Jian; Li Chuanming; Zhou Yang; Xie Bing; Yu Qiongwu; Wang Hui; Qiu Mingguo; Weng Xuchu

    2006-01-01

    Objective: To assess the activation changes on Brodmann areas 17, 18 and 19 in anisometropic amblyopia and compare the features of the cortex activations before and after refractive correction on amblyopic eyes. Methods: Bold-fMRI technique on 1.5 T Simens Sonata MRI and the blocks designation mode was used. The visual stimulation task was a black and white checkerboard with frequencies of 1 cycle/degree and 8 Hz. The baseline stimulus is a white cross-line at the center of the screen with black background. No other light or influence was allowed in the scanning room. The distance between the eyes and screen was 0.6 m. The experimental group included 10 anisometropic amblyopes. TSE and EPI sequence were used for the anatomical and functional data acquisitions. For experimental group, the activation areas of the visual cortex on both eyes were consequently measured before and after refractive correction. All data were analyzed online with t-test and offline with AFNI software. The threshold value was set to 0.001. During data processing, motion correction and three-dimensional smooth were used in all data. The time-signal intensity curves and the functional images were obtained. After Talairach coordinated the function images of every one, the activation areas were measured in Brodmann areas 17, 18 and 19. The SPSS 12.0 software was used for statistic analysis. The difference of the cortical activations of amblyopic eyes before and after refractive correction was analyzed. The cortical activations of amblyopic eyes and the fellow eyes after refractive correction were compared. The visual acuity of the amblyopia eyes was measured. And the correlation between the lesion of cortical activation and visual acuity was analyzed. Results: It was found that the cortex was activated obviously in the calcarine cortex around, occipital lobe, LGN and temporal lobe. The activation areas of amblyopic eyes was (3.7±0.4) x 10 4 voxels, and (4.1±0.5 ) x 10 4 voxets after corrected

  19. [Successive subcortical hemorrhages in the superior parietal lobule and postcentral gyrus in a 23-year-old female].

    Science.gov (United States)

    Sato, K; Yoshikawa, H; Komai, K; Takamori, M

    1998-04-01

    We report a non-hypertensive 23-year-old female with successive hemorrhages in parietal subcortical regions. She had first experienced a transient pain in the left upper extremity one month before admission. She noticed dysesthesia in the same limb and weakness on her left hand, and, five days after, visited our hospital because of suddenly developed convulsion in the limb and loss of consciousness for a few minutes. Neurological examination revealed distal dominant flaccid paresis, positive pathological reflex and touch and position sense disturbances in the affected limb. Brain CT detected two high-density areas in the parietal lobe. Brain MRI demonstrated an acute phase subcortical hematoma in the left postcentral gyrus and a subacute phase one in the left superior parietal lobule. SPECT indicated hypoperfusion in the left frontal and parietal cortex. Cerebral angiography showed no abnormal findings. Her symptoms gradually improved, but left ulnar-type pseudoradicular sensory impairment remained on discharge. We considered the hemorrhage in this patient have arisen from rupture of cavernous hemangioma, because she was relatively young, the hematomas were oval in shape and successively developed in the left parietal lobe. Our patient suggests that a subcortical hemorrhage in the post-central gyrus causes flaccid paresis and pyramidal tract involvement.

  20. Abnormalities in the fatty acid composition of the postmortem entorhinal cortex of patients with schizophrenia, bipolar disorder, and major depressive disorder.

    Science.gov (United States)

    Hamazaki, Kei; Hamazaki, Tomohito; Inadera, Hidekuni

    2013-11-30

    Previous studies of postmortem orbitofrontal cortex have shown abnormalities in levels of n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA), in individuals with schizophrenia, bipolar disorder, and major depressive disorder (MDD). We have previously measured PUFA levels in the postmortem hippocampus from patients with schizophrenia or bipolar disorder and control subjects; however, we found no significant differences between the groups except for small changes in n-6 PUFAs. Furthermore, our study of the postmortem amygdala showed no significant differences in major PUFAs in individuals with schizophrenia, bipolar disorder, or MDD in comparison with controls. In the present study, we investigated whether there were any changes in PUFAs in the entorhinal cortexes of patients with schizophrenia (n=15), bipolar disorder (n=15), or MDD (n=15) compared with unaffected controls (n=15) matched for characteristics including age and sex. In contrast to previous studies of the orbitofrontal cortex and hippocampus, we found no significant differences in major PUFAs. However, we found a 34.3% decrease in docosapentaenoic acid (DPA) (22:5n-3) in patients with MDD and an 8.7% decrease in docosatetraenoic acid (22:4n-6) in those with schizophrenia, compared with controls. Changes in PUFAs in patients with these psychiatric disorders may be specific to certain brain regions. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Abnormal Functional Connectivity of Anterior Cingulate Cortex in Patients With Primary Insomnia: A Resting-State Functional Magnetic Resonance Imaging Study

    Directory of Open Access Journals (Sweden)

    Chao-Qun Yan

    2018-06-01

    Full Text Available Background: Recently, there have been many reports about abnormalities regarding structural and functional brain connectivity of the patients with primary insomnia. However, the alterations in functional interaction between the left and right cerebral hemispheres have not been well understood. The resting-state fMRI approach, which reveals spontaneous neural fluctuations in blood-oxygen-level-dependent signals, offers a method to quantify functional interactions between the hemispheres directly.Methods: We compared interhemispheric functional connectivity (FC between 26 patients with primary insomnia (48.85 ± 12.02 years and 28 healthy controls (49.07 ± 11.81 years using a voxel-mirrored homotopic connectivity (VMHC method. The patients with primary insomnia and healthy controls were matched for age, gender, and education. Brain regions, which had significant differences in VMHC maps between the primary insomnia and healthy control groups, were defined as seed region of interests. A seed-based approach was further used to reveal significant differences of FC between the seeds and the whole contralateral hemisphere.Results: The patients with primary insomnia showed higher VMHC than healthy controls in the anterior cingulate cortex (ACC bilaterally. The seed-based analyses demonstrated increased FC between the left ACC and right thalamus (and the right ACC and left orbitofrontal cortex in patients with primary insomnia, revealing abnormal connectivity between the two cerebral hemispheres. The VMHC values in the ACC were positively correlated with the time to fall asleep and Self-Rating Depression Scale scores (SDS.Conclusions: The results demonstrate that there is abnormal interhemispheric resting-state FC in the brain regions of patients with primary insomnia, especially in the ACC. Our finding demonstrates valid evidence that the ACC is an area of interest in the neurobiology of primary insomnia.

  2. Effect of Panax notoginseng saponins on the expression of beta-amyloid protein in the cortex of the parietal lobe and hippocampus, and spatial learning and memory in a mouse model of senile dementia

    Institute of Scientific and Technical Information of China (English)

    Zhenguo Zhong; Dengpan Wu; Liang Lü; Jinsheng Wang; Wenyan Zhang; Zeqiang Qu

    2008-01-01

    immunohistochemistry. The mRNA content of App, tau, acetylcholinesterase, and synaptophysin (Syp) was tested by real time PCR and RT-PCR.RESULTS: The PCR results show that PNS can downregulate the expression of the App gene and upregulate the expression of the Syp gene in the parietal cortex and hippocampus of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than those of the PNS low-dosage group and the huperzine A group (P < 0.05). The results of the Morris water maze and immunohistochemistry indicated that PNS can improve the capacity for spatial learning and memory in SAMP8 mice, and reduce the content of A β1-40,A β1-42 and expression of App in the brains of SAMP8 mice. The therapeutic effects of the PNS high-dosage group were greater than that of the PNS low-dosage group and the huperzine A group (P < 0.05).CONCLUSION: These results support the hypothesis that PNS plays a therapeutic and protective role on the pathological lesions and learning dysfunction of Alzheimer's disease. The therapeutic effects of PNS for Alzheimer's disease are possibly achieved through downregulating the expression of the App gene and upregulating the expression of the Syp gene. The therapeutic effects of PNS are dose-dependent and are greater than the effect of huperzine A.

  3. Abnormal Brain Activation During Theory of Mind Tasks in Schizophrenia: A Meta-Analysis.

    Science.gov (United States)

    Kronbichler, Lisa; Tschernegg, Melanie; Martin, Anna Isabel; Schurz, Matthias; Kronbichler, Martin

    2017-10-21

    Social cognition abilities are severely impaired in schizophrenia (SZ). The current meta-analysis used foci of 21 individual studies on functional abnormalities in the schizophrenic brain in order to identify regions that reveal convergent under- or over-activation during theory of mind (TOM) tasks. Studies were included in the analyses when contrasting tasks that require the processing of mental states with tasks which did not. Only studies that investigated patients with an ICD or DSM diagnosis were included. Quantitative voxel-based meta-analyses were done using Seed-based d Mapping software. Common TOM regions like medial-prefrontal cortex and temporo-parietal junction revealed abnormal activation in schizophrenic patients: Under-activation was identified in the medial prefrontal cortex, left orbito-frontal cortex, and in a small section of the left posterior temporo-parietal junction. Remarkably, robust over-activation was identified in a more dorsal, bilateral section of the temporo-parietal junction. Further abnormal activation was identified in medial occipito-parietal cortex, right premotor areas, left cingulate gyrus, and lingual gyrus. The findings of this study suggest that SZ patients simultaneously show over- and under-activation in TOM-related regions. Especially interesting, temporo-parietal junction reveals diverging activation patterns with an under-activating left posterior and an over-activating bilateral dorsal section. In conclusion, SZ patients show less specialized brain activation in regions linked to TOM and increased activation in attention-related networks suggesting compensatory effects. © The Author 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.

  4. The effects of abnormalities of glucose homeostasis on the expression and binding of muscarinic receptors in cerebral cortex of rats.

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    Sherin, Antony; Peeyush, Kumar T; Naijil, George; Nandhu, Mohan Sobhana; Jayanarayanan, Sadanandan; Jes, Paul; Paulose, Cheramadathikudiyil Skaria

    2011-01-25

    Glucose homeostasis in humans is an important factor for the functioning of nervous system. Both hypo and hyperglycemia contributes to neuronal functional deficit. In the present study, effect of insulin induced hypoglycemia and streptozotocin induced diabetes on muscarinic receptor binding, cholinergic enzymes; AChE, ChAT expression and GLUT3 in the cerebral cortex of experimental rats were analysed. Total muscarinic, muscarinic M(1) receptor showed a significant decrease and muscarinic M(3) receptor subtype showed a significant increased binding in the cerebral cortex of hypoglycemic rats compared to diabetic and control. Real-Time PCR analysis of muscarinic M(1), M(3) receptor subtypes confirmed the receptor binding studies. Immunohistochemistry of muscarinic M(1), M(3) receptors using specific antibodies were also carried out. AChE and GLUT3 expression up regulated and ChAT expression down regulated in hypoglycemic rats compared to diabetic and control rats. Our results showed that hypo/hyperglycemia caused impaired glucose transport in neuronal cells as shown by altered expression of GLUT3. Increased AChE and decreased ChAT expression is suggested to alter cortical acetylcholine metabolism in experimental rats along with altered muscarinic receptor binding in hypo/hyperglycemic rats, impair cholinergic transmission, which subsequently lead to cholinergic dysfunction thereby causing learning and memory deficits. We observed a prominent cholinergic functional disturbance in hypoglycemic condition than in hyperglycemia. Hypoglycemia exacerbated the neurochemical changes in cerebral cortex induced by hyperglycemia. These findings have implications for both therapy and identification of causes contributing to neuronal dysfunction in diabetes. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Switching between internally and externally focused attention in obsessive-compulsive disorder: Abnormal visual cortex activation and connectivity.

    Science.gov (United States)

    Stern, Emily R; Muratore, Alexandra F; Taylor, Stephan F; Abelson, James L; Hof, Patrick R; Goodman, Wayne K

    2017-07-30

    Obsessive-compulsive disorder (OCD) is characterized by excessive absorption with internally-generated distressing thoughts and urges, with difficulty incorporating external information running counter to their fears and concerns. In the present study, we experimentally probed this core feature of OCD through the use of a novel attention switching task that investigates transitions between internally focused (IF) and externally focused (EF) attentional states. Eighteen OCD patients and 18 controls imagined positive and negative personal event scenarios (IF state) or performed a color-word Stroop task (EF state). The IF/EF states were followed by a target detection (TD) task requiring responses to external stimuli. Compared to controls, OCD patients made significantly more errors and showed reduced activation of superior and inferior occipital cortex, thalamus, and putamen during TD following negative IF, with the inferior occipital hypoactivation being significantly greater for TD following negative IF compared to TD following the other conditions. Patients showed stronger functional connectivity between the inferior occipital region and dorsomedial prefrontal cortex. These findings point to an OCD-related impairment in the visual processing of external stimuli specifically when they follow a period of negative internal focus, and suggest that future treatments may wish to target the transition between attentional states. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Predicting oculomotor behaviour from correlated populations of posterior parietal neurons.

    Science.gov (United States)

    Graf, Arnulf B A; Andersen, Richard A

    2015-01-23

    Oculomotor function critically depends on how signals representing saccade direction and eye position are combined across neurons in the lateral intraparietal (LIP) area of the posterior parietal cortex. Here we show that populations of parietal neurons exhibit correlated variability, and that using these interneuronal correlations yields oculomotor predictions that are more accurate and also less uncertain. The structure of LIP population responses is therefore essential for reliable read-out of oculomotor behaviour.

  7. Spatial imagery relies on a sensory independent, though sensory sensitive, functional organization within the parietal cortex: a fMRI study of angle discrimination in sighted and congenitally blind individuals.

    Science.gov (United States)

    Bonino, Daniela; Ricciardi, Emiliano; Bernardi, Giulio; Sani, Lorenzo; Gentili, Claudio; Vecchi, Tomaso; Pietrini, Pietro

    2015-02-01

    Although vision offers distinctive information to space representation, individuals who lack vision since birth often show perceptual and representational skills comparable to those found in sighted individuals. However, congenitally blind individuals may result in impaired spatial analysis, when engaging in 'visual' spatial features (e.g., perspective or angle representation) or complex spatial mental abilities. In the present study, we measured behavioral and brain responses using functional magnetic resonance imaging in sighted and congenitally blind individuals during spatial imagery based on a modified version of the mental clock task (e.g., angle discrimination) and a simple recognition control condition, as conveyed across distinct sensory modalities: visual (sighted individuals only), tactile and auditory. Blind individuals were significantly less accurate during the auditory task, but comparable-to-sighted during the tactile task. As expected, both groups showed common neural activations in intraparietal and superior parietal regions across visual and non-visual spatial perception and imagery conditions, indicating the more abstract, sensory independent functional organization of these cortical areas, a property that we named supramodality. At the same time, however, comparisons in brain responses and functional connectivity patterns across experimental conditions demonstrated also a functional lateralization, in a way that correlated with the distinct behavioral performance in blind and sighted individuals. Specifically, blind individuals relied more on right parietal regions, mainly in the tactile and less in the auditory spatial processing. In sighted, spatial representation across modalities relied more on left parietal regions. In conclusions, intraparietal and superior parietal regions subserve supramodal spatial representations in sighted and congenitally blind individuals. Differences in their recruitment across non-visual spatial processing in

  8. Abnormal development of sensory-motor, visual temporal and parahippocampal cortex in children with learning disabilities and borderline intellectual functioning

    Directory of Open Access Journals (Sweden)

    Francesca eBaglio

    2014-10-01

    Full Text Available Borderline intellectual functioning (BIF is a condition characterized by an intelligence quotient (IQ between 70 and 85. BIF children present with cognitive, motor, social and adaptive limitations that result in learning disabilities and are more likely to develop psychiatric disorders later in life. Aim of this study was to investigate brain morphometry and its relation to IQ level in borderline intellectual functioning children.Thirteen children with BIF and 14 age- and sex-matched typically developing children were enrolled. All children underwent a full IQ assessment (WISC-III scale and a Magnetic Resonance (MR examination including conventional sequences to assess brain structural abnormalities and high resolution 3D images for voxel based morphometry (VBM analysis. To investigate to what extent the group influenced gray matter volumes, both univariate and multivariate generalized linear model analysis of variance were used, and the varimax factor analysis was used to explore variable correlations and clusters among subjects. Results showed that BIF children, compared to controls have increased regional gray matter volume in bilateral sensori-motor and right posterior temporal cortices and decreased gray matter volume in right parahippocampal gyrus. Gray matter volumes were highly correlated with IQ indices.Our is a case study of a group of BIF children showing that BIF is associated with abnormal cortical development in brain areas that have a pivotal role in motor, learning and behavioral processes. Our findings, although allowing for little generalization to general population, contributes to the very limited knowledge in this field. Future longitudinal MR studies will be useful in verifying whether cortical features can be modified over time even in association with rehabilitative intervention.

  9. The mirror mechanism in the parietal lobe.

    Science.gov (United States)

    Rizzolatti, Giacomo; Rozzi, Stefano

    2018-01-01

    The mirror mechanism is a basic mechanism that transforms sensory representations of others' actions into motor representations of the same actions in the brain of the observer. The mirror mechanism plays an important role in understanding actions of others. In the present chapter we discuss first the basic organization of the posterior parietal lobe in the monkey, stressing that it is best characterized as a motor scaffold, on the top of which sensory information is organized. We then describe the location of the mirror mechanism in the posterior parietal cortex of the monkey, and its functional role in areas PFG, and anterior, ventral, and lateral intraparietal areas. We will then present evidence that a similar functional organization is present in humans. We will conclude by discussing the role of the mirror mechanism in the recognition of action performed with tools. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Cortical thickness abnormalities in late adolescence with online gaming addiction.

    Science.gov (United States)

    Yuan, Kai; Cheng, Ping; Dong, Tao; Bi, Yanzhi; Xing, Lihong; Yu, Dahua; Zhao, Limei; Dong, Minghao; von Deneen, Karen M; Liu, Yijun; Qin, Wei; Tian, Jie

    2013-01-01

    Online gaming addiction, as the most popular subtype of Internet addiction, had gained more and more attention from the whole world. However, the structural differences in cortical thickness of the brain between adolescents with online gaming addiction and healthy controls are not well unknown; neither was its association with the impaired cognitive control ability. High-resolution magnetic resonance imaging scans from late adolescence with online gaming addiction (n = 18) and age-, education- and gender-matched controls (n = 18) were acquired. The cortical thickness measurement method was employed to investigate alterations of cortical thickness in individuals with online gaming addiction. The color-word Stroop task was employed to investigate the functional implications of the cortical thickness abnormalities. Imaging data revealed increased cortical thickness in the left precentral cortex, precuneus, middle frontal cortex, inferior temporal and middle temporal cortices in late adolescence with online gaming addiction; meanwhile, the cortical thicknesses of the left lateral orbitofrontal cortex (OFC), insula, lingual gyrus, the right postcentral gyrus, entorhinal cortex and inferior parietal cortex were decreased. Correlation analysis demonstrated that the cortical thicknesses of the left precentral cortex, precuneus and lingual gyrus correlated with duration of online gaming addiction and the cortical thickness of the OFC correlated with the impaired task performance during the color-word Stroop task in adolescents with online gaming addiction. The findings in the current study suggested that the cortical thickness abnormalities of these regions may be implicated in the underlying pathophysiology of online gaming addiction.

  11. Cortical thickness abnormalities in late adolescence with online gaming addiction.

    Directory of Open Access Journals (Sweden)

    Kai Yuan

    Full Text Available Online gaming addiction, as the most popular subtype of Internet addiction, had gained more and more attention from the whole world. However, the structural differences in cortical thickness of the brain between adolescents with online gaming addiction and healthy controls are not well unknown; neither was its association with the impaired cognitive control ability. High-resolution magnetic resonance imaging scans from late adolescence with online gaming addiction (n = 18 and age-, education- and gender-matched controls (n = 18 were acquired. The cortical thickness measurement method was employed to investigate alterations of cortical thickness in individuals with online gaming addiction. The color-word Stroop task was employed to investigate the functional implications of the cortical thickness abnormalities. Imaging data revealed increased cortical thickness in the left precentral cortex, precuneus, middle frontal cortex, inferior temporal and middle temporal cortices in late adolescence with online gaming addiction; meanwhile, the cortical thicknesses of the left lateral orbitofrontal cortex (OFC, insula, lingual gyrus, the right postcentral gyrus, entorhinal cortex and inferior parietal cortex were decreased. Correlation analysis demonstrated that the cortical thicknesses of the left precentral cortex, precuneus and lingual gyrus correlated with duration of online gaming addiction and the cortical thickness of the OFC correlated with the impaired task performance during the color-word Stroop task in adolescents with online gaming addiction. The findings in the current study suggested that the cortical thickness abnormalities of these regions may be implicated in the underlying pathophysiology of online gaming addiction.

  12. Abnormal functional connectivity of the posterior cingulate cortex is associated with depressive symptoms in patients with Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Zhang J

    2017-10-01

    Full Text Available Jiangtao Zhang,1,2 Zhongwei Guo,2 Xiaozheng Liu,3 Xize Jia,4 Jiapeng Li,2 Yaoyao Li,1,5 Danmei Lv,1,5 Wei Chen1,5 1Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine and the Collaborative Innovation Center for Brain Science, Hangzhou, Zhejiang, China; 2Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang, China; 3China-USA Neuroimaging Research Institute & Department of Radiology, the Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, China; 4Center for Cognitive Brain Disorders & Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou Normal University, Hangzhou, China; 5Key Laboratory of Medical Neurobiology of Chinese Ministry of Health, Hangzhou, Zhejiang, China Background: Depressive symptoms are significant and very common psychiatric complications in patients with Alzheimer’s disease (AD, which can aggravate the decline in social function. However, changes in the functional connectivity (FC of the brain in AD patients with depressive symptoms (D-AD remain unclear.Objective: To investigate whether any differences exist in the FC of the posterior cingulate cortex (PCC between D-AD patients and non-depressed AD patients (nD-AD.Materials and methods: We recruited 15 D-AD patients and 17 age-, sex-, educational level-, and Mini-Mental State Examination (MMSE-matched nD-AD patients to undergo tests using the Neuropsychiatric Inventory, Hamilton Depression Rating Scale, and 3.0T resting-state functional magnetic resonance imaging. Bilateral PCC were selected as the regions of interest and between-group differences in the PCC FC network were assessed using Student’s t-test.Results: Compared with the nD-AD group, D-AD patients showed increased PCC FC in the right amygdala, right parahippocampus, right superior temporal pole, right middle temporal lobe, right middle temporal pole, and right hippocampus (AlphaSim correction; P<0.05. In the nD-AD group, MMSE

  13. Xenomelia: a new right parietal lobe syndrome.

    Science.gov (United States)

    McGeoch, Paul D; Brang, David; Song, Tao; Lee, Roland R; Huang, Mingxiong; Ramachandran, V S

    2011-12-01

    Damage to the right parietal lobe has long been associated with various disorders of body image. The authors have recently suggested that an unusual behavioural condition in which otherwise rational individuals desire the amputation of a healthy limb might also arise from right parietal dysfunction. Four subjects who desired the amputation of healthy legs (two right, one left and one, at first, bilateral and then left only) were recruited and underwent magnetoencephalography (MEG) scans during tactile stimulation of sites above and below the desired amputation line. Regions of interest (ROIs) in each hemisphere (superior parietal lobule (SPL), inferior parietal lobule, S1, M1, insula, premotor cortex and precuneus) were defined using FreeSurfer software. Analysis of average MEG activity across the 40-140 ms post-stimulation timeframe was carried out using an unpaired t test. This revealed significantly reduced activation only in the right SPL ROI for the subjects' affected legs when compared with both subjects' unaffected legs and that of controls. The right SPL is a cortical area that appears ideally placed to unify disparate sensory inputs to create a coherent sense of having a body. The authors propose that inadequate activation of the right SPL leads to the unnatural situation in which the sufferers can feel the limb in question being touched without it actually incorporating into their body image, with a resulting desire for amputation. The authors introduce the term 'xenomelia' as a more appropriate name than apotemnophilia or body integrity identity disorder, for what appears to be an unrecognised right parietal lobe syndrome.

  14. Parietal lesion effects on cued recall following pair associate learning.

    Science.gov (United States)

    Ben-Zvi, Shir; Soroker, Nachum; Levy, Daniel A

    2015-07-01

    We investigated the involvement of the posterior parietal cortex in episodic memory in a lesion-effects study of cued recall following pair-associate learning. Groups of patients who had experienced first-incident stroke, generally in middle cerebral artery territory, and exhibited damage that included lateral posterior parietal regions, were tested within an early post-stroke time window. In three experiments, patients and matched healthy comparison groups executed repeated study and cued recall test blocks of pairs of words (Experiment 1), pairs of object pictures (Experiment 2), or pairs of object pictures and environmental sounds (Experiment 3). Patients' brain CT scans were subjected to quantitative analysis of lesion volumes. Behavioral and lesion data were used to compute correlations between area lesion extent and memory deficits, and to conduct voxel-based lesion-symptom mapping. These analyses implicated lateral ventral parietal cortex, especially the angular gyrus, in cued recall deficits, most pronouncedly in the cross-modal picture-sound pairs task, though significant parietal lesion effects were also found in the unimodal word pairs and picture pairs tasks. In contrast to an earlier study in which comparable parietal lesions did not cause deficits in item recognition, these results indicate that lateral posterior parietal areas make a substantive contribution to demanding forms of recollective retrieval as represented by cued recall, especially for complex associative representations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Intradiploic encephalocele of the left parietal bone: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok [Myongji St. Mary' s Hospital, Seoul (Korea, Republic of)

    2015-06-15

    Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood.

  16. Intradiploic encephalocele of the left parietal bone: A case report

    International Nuclear Information System (INIS)

    Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok

    2015-01-01

    Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood

  17. Abnormal Functional Connectivity Density in Post-traumatic Stress Disorder.

    Science.gov (United States)

    Zhang, Youxue; Xie, Bing; Chen, Heng; Li, Meiling; Liu, Feng; Chen, Huafu

    2016-05-01

    Post-traumatic stress disorder (PTSD) is a psychiatric disorder that occurs in individuals who have experienced life-threatening mental traumas. Previous neuroimaging studies have indicated that the pathology of PTSD may be associated with the abnormal functional integration among brain regions. In the current study, we used functional connectivity density (FCD) mapping, a novel voxel-wise data-driven approach based on graph theory, to explore aberrant FC through the resting-state functional magnetic resonance imaging of the PTSD. We calculated both short- and long-range FCD in PTSD patients and healthy controls (HCs). Compared with HCs, PTSD patients showed significantly increased long-range FCD in the left dorsolateral prefrontal cortex (DLPFC), but no abnormal short-range FCD was found in PTSD. Furthermore, seed-based FC analysis of the left DLPFC showed increased connectivity in the left superior parietal lobe and visual cortex of PTSD patients. The results suggested that PTSD patients experienced a disruption of intrinsic long-range functional connections in the fronto-parietal network and visual cortex, which are associated with attention control and visual information processing.

  18. Abnormal gray matter volume and impulsivity in young adults with Internet gaming disorder.

    Science.gov (United States)

    Lee, Deokjong; Namkoong, Kee; Lee, Junghan; Jung, Young-Chul

    2017-09-08

    Reduced executive control is one of the central components of model on the development and maintenance of Internet gaming disorder (IGD). Among the various executive control problems, high impulsivity has consistently been associated with IGD. We performed voxel-based morphometric analysis with diffeomorphic anatomical registration by using an exponentiated Lie algebra algorithm (DARTEL) to investigate the relationship of gray matter abnormalities to impulsivity in IGD. Thirty-one young male adults whose excessive Internet gaming began in early adolescence, and 30 age-matched male healthy controls were examined. IGD subjects showed smaller gray matter volume (GMV) in brain regions implicated in executive control, such as the anterior cingulate cortex and the supplementary motor area. The GMVs in the anterior cingulate cortex and the supplementary motor area were negatively correlated with self-reporting scales of impulsiveness. IGD subjects also exhibited smaller GMV in lateral prefrontal and parietal cortices comprising the left ventrolateral prefrontal cortex and the left inferior parietal lobule when compared with healthy controls. The GMVs in the left ventrolateral prefrontal cortex were negatively correlated with lifetime usage of Internet gaming. These findings suggest that gray matter abnormalities in areas related to executive control may contribute to high impulsivity of young adults with IGD. Furthermore, alterations in the prefrontal cortex were related with long-term excessive Internet gaming during adolescence. © 2017 Society for the Study of Addiction.

  19. Development of parietal bone surrogates for parietal graft lift training

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    Hollensteiner Marianne

    2016-09-01

    Full Text Available Currently the surgical training of parietal bone graft techniques is performed on patients or specimens. Commercially available bone models do not deliver realistic haptic feedback. Thus customized parietal skull surrogates were developed for surgical training purposes. Two human parietal bones were used as reference. Based on the measurement of insertion forces of drilling, milling and saw procedures suitable material compositions for molding cortical and cancellous calvarial layers were found. Artificial skull caps were manufactured and tested. Additionally microtomograpy images of human and artificial parietal bones were performed to analyze outer table and diploe thicknesses. Significant differences between human and artificial skulls were not detected with the mechanical procedures tested. Highly significant differences were found for the diploe thickness values. In conclusion, an artificial bone has been created, mimicking the properties of human parietal bone thus being suitable for tabula externa graft lift training.

  20. Bilateral, posterior parietal polymicrogyria as part of speech therapy ...

    African Journals Online (AJOL)

    in abnormal development of the deep layers of the cerebral cortex and production ... focal, unilateral, bilateral or asymmetrical, and have been described in all areas of .... did not recognise food in the mouth, no tongue movement was observed.

  1. Distinct timescales of population coding across cortex.

    Science.gov (United States)

    Runyan, Caroline A; Piasini, Eugenio; Panzeri, Stefano; Harvey, Christopher D

    2017-08-03

    The cortex represents information across widely varying timescales. For instance, sensory cortex encodes stimuli that fluctuate over few tens of milliseconds, whereas in association cortex behavioural choices can require the maintenance of information over seconds. However, it remains poorly understood whether diverse timescales result mostly from features intrinsic to individual neurons or from neuronal population activity. This question remains unanswered, because the timescales of coding in populations of neurons have not been studied extensively, and population codes have not been compared systematically across cortical regions. Here we show that population codes can be essential to achieve long coding timescales. Furthermore, we find that the properties of population codes differ between sensory and association cortices. We compared coding for sensory stimuli and behavioural choices in auditory cortex and posterior parietal cortex as mice performed a sound localization task. Auditory stimulus information was stronger in auditory cortex than in posterior parietal cortex, and both regions contained choice information. Although auditory cortex and posterior parietal cortex coded information by tiling in time neurons that were transiently informative for approximately 200 milliseconds, the areas had major differences in functional coupling between neurons, measured as activity correlations that could not be explained by task events. Coupling among posterior parietal cortex neurons was strong and extended over long time lags, whereas coupling among auditory cortex neurons was weak and short-lived. Stronger coupling in posterior parietal cortex led to a population code with long timescales and a representation of choice that remained consistent for approximately 1 second. In contrast, auditory cortex had a code with rapid fluctuations in stimulus and choice information over hundreds of milliseconds. Our results reveal that population codes differ across cortex

  2. Sylvian Fissure and Parietal Anatomy in Children with Autism Spectrum Disorder

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    Tracey A. Knaus

    2012-01-01

    Full Text Available Autism spectrum disorder (ASD is characterized by deficits in social functioning and language and communication, with restricted interests or stereotyped behaviors. Anatomical differences have been found in the parietal cortex in children with ASD, but parietal subregions and associations between Sylvian fissure (SF and parietal anatomy have not been explored. In this study, SF length and anterior and posterior parietal volumes were measured on MRI in 30 right-handed boys with ASD and 30 right-handed typically developing boys (7–14 years, matched on age and non-verbal IQ. There was leftward SF and anterior parietal asymmetry, and rightward posterior parietal asymmetry, across groups. There were associations between SF and parietal asymmetries, with slight group differences. Typical SF asymmetry was associated with typical anterior and posterior parietal asymmetry, in both groups. In the atypical SF asymmetry group, controls had atypical parietal asymmetry, whereas in ASD there were more equal numbers of individuals with typical as atypical anterior parietal asymmetry. We did not find significant anatomical-behavioral associations. Our findings of more individuals in the ASD group having a dissociation between cortical asymmetries warrants further investigation of these subgroups and emphasizes the importance of investigating anatomical relationships in addition to group differences in individual regions.

  3. Choline acetyltransferase-containing neurons in the human parietal neocortex

    Directory of Open Access Journals (Sweden)

    V Benagiano

    2009-06-01

    Full Text Available A number of immunocytochemical studies have indicated the presence of cholinergic neurons in the cerebral cortex of various species of mammals. Whether such cholinergic neurons in the human cerebral cortex are exclusively of subcortical origin is still debated. In this immunocytochemical study, the existence of cortical cholinergic neurons was investigated on surgical samples of human parietal association neocortex using a highly specific monoclonal antibody against choline acetyltransferase (ChAT, the acetylcholine biosynthesising enzyme. ChAT immunoreactivity was detected in a subpopulation of neurons located in layers II and III. These were small or medium-sized pyramidal neurons which showed cytoplasmic immunoreactivity in the perikarya and processes, often in close association to blood microvessels. This study, providing demonstration of ChAT neurons in the human parietal neocortex, strongly supports the existence of intrinsic cholinergic innervation of the human neocortex. It is likely that these neurons contribute to the cholinergic innervation of the intracortical microvessels.

  4. Brain abnormalities in murderers indicated by positron emission tomography.

    Science.gov (United States)

    Raine, A; Buchsbaum, M; LaCasse, L

    1997-09-15

    Murderers pleading not guilty by reason of insanity (NGRI) are thought to have brain dysfunction, but there have been no previous studies reporting direct measures of both cortical and subcortical brain functioning in this specific group. Positron emission tomography brain imaging using a continuous performance challenge task was conducted on 41 murderers pleading not guilty by reason of insanity and 41 age- and sex-matched controls. Murderers were characterized by reduced glucose metabolism in the prefrontal cortex, superior parietal gyrus, left angular gyrus, and the corpus callosum, while abnormal asymmetries of activity (left hemisphere lower than right) were also found in the amygdala, thalamus, and medial temporal lobe. These preliminary findings provide initial indications of a network of abnormal cortical and subcortical brain processes that may predispose to violence in murderers pleading NGRI.

  5. Changes in Cerebral Cortex of Children Treated for Medulloblastoma

    International Nuclear Information System (INIS)

    Liu, Arthur K.; Marcus, Karen J.; Fischl, Bruce; Grant, P. Ellen; Young Poussaint, Tina; Rivkin, Michael J.; Davis, Peter; Tarbell, Nancy J.; Yock, Torunn I.

    2007-01-01

    Purpose: Children with medulloblastoma undergo surgery, radiotherapy, and chemotherapy. After treatment, these children have numerous structural abnormalities. Using high-resolution magnetic resonance imaging, we measured the thickness of the cerebral cortex in a group of medulloblastoma patients and a group of normally developing children. Methods and Materials: We obtained magnetic resonance imaging scans and measured the cortical thickness in 9 children after treatment of medulloblastoma. The measurements from these children were compared with the measurements from age- and gender-matched normally developing children previously scanned. For additional comparison, the pattern of thickness change was compared with the cortical thickness maps from a larger group of 65 normally developing children. Results: In the left hemisphere, relatively thinner cortex was found in the perirolandic region and the parieto-occipital lobe. In the right hemisphere, relatively thinner cortex was found in the parietal lobe, posterior superior temporal gyrus, and lateral temporal lobe. These regions of cortical thinning overlapped with the regions of cortex that undergo normal age-related thinning. Conclusion: The spatial distribution of cortical thinning suggested that the areas of cortex that are undergoing development are more sensitive to the effects of treatment of medulloblastoma. Such quantitative methods may improve our understanding of the biologic effects that treatment has on the cerebral development and their neuropsychological implications

  6. Regional cerebral blood flow abnormalities in patients with primary hyperparathyroidism

    International Nuclear Information System (INIS)

    Cermik, Tevfik F.; Kaya, Meryem; Bedel, Deniz; Berkarda, Sakir; Yigitbasi, Oemer N.; Ugur-Altun, Betuel

    2007-01-01

    We assessed the alterations in regional cerebral blood flow (rCBF) in patients with primary hyperparathyroidism (PHP) before parathyroidectomy by semiquantitative analysis of brain single photon emission computed tomography (SPECT) images. Included in this prospective study were 14 patients (mean age 47.6 ± 10.4 years; 3 male, 11 female) and 10 control subjects (mean age 36.0 ± 8.5 years, 6 male, 4 female) were SPECT imaging was performed using a dual-headed gamma camera 60-90 min after intravenous administration of 925 MBq Tc-99m HMPAO. The corticocerebellar rCBF ratios were calculated from 52 brain areas and reference lower values (RLVs) were calculated from the rCBF ratios of control subjects. The regional ratios that were below the corresponding RLV were considered abnormal (hypoperfused). Hypoperfusion was shown in 171 out of 728 regions (23%) and there was a significant correlation between serum calcium, PTH levels and the sum of hypoperfused regions in the patient group (R = 0.75 and P = 0.001, and R = 0.75, P = 0.001, respectively). Significantly reduced rCBF were found in the following cortical regions: bilateral cingulate cortex, superior and inferior frontal cortex, anterior temporal cortex, precentral gyrus, postcentral gyrus and parietal cortex, and right posterior temporal cortex. Our results indicate that alterations in rCBF in patients with PHP can be demonstrated with brain SPECT. The correlation between serum calcium, PTH levels and the sum of hypoperfused regions indicates that there may be a strong relationship between rCBF abnormalities and increased levels of serum calcium and PTH. In addition, the degree of rCBF abnormalities could be determined by brain SPECT in PHP patients with or without psychiatric symptoms. (orig.)

  7. Regional cerebral blood flow abnormalities in patients with primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Cermik, Tevfik F. [Hospital of the University of Trakya, Department of Nuclear Medicine, Edirne (Turkey); Trakya Universitesi Hastanesi, Nukleer Tip Anabilim Dali, Gullapoglu Yerleskesi, Edirne (Turkey); Kaya, Meryem; Bedel, Deniz; Berkarda, Sakir; Yigitbasi, Oemer N. [Hospital of the University of Trakya, Department of Nuclear Medicine, Edirne (Turkey); Ugur-Altun, Betuel [Hospital of the University of Trakya, Department of Internal Medicine, Division of Endocrinology, Edirne (Turkey)

    2007-04-15

    We assessed the alterations in regional cerebral blood flow (rCBF) in patients with primary hyperparathyroidism (PHP) before parathyroidectomy by semiquantitative analysis of brain single photon emission computed tomography (SPECT) images. Included in this prospective study were 14 patients (mean age 47.6 {+-} 10.4 years; 3 male, 11 female) and 10 control subjects (mean age 36.0 {+-} 8.5 years, 6 male, 4 female) were SPECT imaging was performed using a dual-headed gamma camera 60-90 min after intravenous administration of 925 MBq Tc-99m HMPAO. The corticocerebellar rCBF ratios were calculated from 52 brain areas and reference lower values (RLVs) were calculated from the rCBF ratios of control subjects. The regional ratios that were below the corresponding RLV were considered abnormal (hypoperfused). Hypoperfusion was shown in 171 out of 728 regions (23%) and there was a significant correlation between serum calcium, PTH levels and the sum of hypoperfused regions in the patient group (R = 0.75 and P = 0.001, and R = 0.75, P = 0.001, respectively). Significantly reduced rCBF were found in the following cortical regions: bilateral cingulate cortex, superior and inferior frontal cortex, anterior temporal cortex, precentral gyrus, postcentral gyrus and parietal cortex, and right posterior temporal cortex. Our results indicate that alterations in rCBF in patients with PHP can be demonstrated with brain SPECT. The correlation between serum calcium, PTH levels and the sum of hypoperfused regions indicates that there may be a strong relationship between rCBF abnormalities and increased levels of serum calcium and PTH. In addition, the degree of rCBF abnormalities could be determined by brain SPECT in PHP patients with or without psychiatric symptoms. (orig.)

  8. [Neuroanatomy of Frontal Association Cortex].

    Science.gov (United States)

    Takada, Masahiko

    2016-11-01

    The frontal association cortex is composed of the prefrontal cortex and the motor-related areas except the primary motor cortex (i.e., the so-called higher motor areas), and is well-developed in primates, including humans. The prefrontal cortex receives and integrates large bits of diverse information from the parietal, temporal, and occipital association cortical areas (termed the posterior association cortex), and paralimbic association cortical areas. This information is then transmitted to the primary motor cortex via multiple motor-related areas. Given these facts, it is likely that the prefrontal cortex exerts executive functions for behavioral control. The functional input pathways from the posterior and paralimbic association cortical areas to the prefrontal cortex are classified primarily into six groups. Cognitive signals derived from the prefrontal cortex are conveyed to the rostral motor-related areas to transform them into motor signals, which finally enter the primary motor cortex via the caudal motor-related areas. Furthermore, it has been shown that, similar to the primary motor cortex, areas of the frontal association cortex form individual networks (known as "loop circuits") with the basal ganglia and cerebellum via the thalamus, and hence are extensively involved in the expression and control of behavioral actions.

  9. Differentiated parietal connectivity of frontal regions for "what" and "where" memory.

    Science.gov (United States)

    Rottschy, C; Caspers, S; Roski, C; Reetz, K; Dogan, I; Schulz, J B; Zilles, K; Laird, A R; Fox, P T; Eickhoff, S B

    2013-11-01

    In a previous meta-analysis across almost 200 neuroimaging experiments, working memory for object location showed significantly stronger convergence on the posterior superior frontal gyrus, whereas working memory for identity showed stronger convergence on the posterior inferior frontal gyrus (dorsal to, but overlapping with Brodmann's area BA 44). As similar locations have been discussed as part of a dorsal frontal-superior parietal reach system and an inferior frontal grasp system, the aim of the present study was to test whether the regions of working-memory related "what" and "where" processing show a similar distinction in parietal connectivity. The regions that were found in the previous meta-analysis were used as seeds for functional connectivity analyses using task-based meta-analytic connectivity modelling and task-independent resting state correlations. While the ventral seed showed significantly stronger connectivity with the bilateral intraparietal sulcus (IPS), the dorsal seed showed stronger connectivity with the bilateral posterior inferior parietal and the medial superior parietal lobule. The observed connections of regions involved in memory for object location and identity thus clearly demonstrate a distinction into separate pathways that resemble the parietal connectivity patterns of the dorsal and ventral premotor cortex in non-human primates and humans. It may hence be speculated that memory for a particular location and reaching towards it as well as object memory and finger positioning for manipulation may rely on shared neural systems. Moreover, the ensuing regions, in turn, featured differential connectivity with the bilateral ventral and dorsal extrastriate cortex, suggesting largely segregated bilateral connectivity pathways from the dorsal visual cortex via the superior and inferior parietal lobules to the dorsal posterior frontal cortex and from the ventral visual cortex via the IPS to the ventral posterior frontal cortex that may

  10. Abnormal short-latency synaptic plasticity in the motor cortex of subjects with Becker muscular dystrophy: a rTMS study.

    Science.gov (United States)

    Golaszewski, Stefan; Schwenker, Kerstin; Bergmann, Jürgen; Brigo, Francesco; Christova, Monica; Trinka, Eugen; Nardone, Raffaele

    2016-01-01

    We used repetitive transcranial magnetic stimulation (rTMS) to further investigate motor cortex excitability in 13 patients with Becker muscular dystrophy (BMD), six of them with slight mental retardation. RTMS delivered at 5Hz frequency and suprathreshold intensity progressively increases the size of motor evoked potentials (MEPs) in healthy subjects; the rTMS-induced facilitation of MEPs was significantly reduced in the BMD patients mentally retarded or classified as borderline when compared with age-matched control subjects and the BMD patients with normal intelligence. The increase in the duration of the cortical silent period was similar in both patient groups and controls. These findings suggest an altered cortical short-term synaptic plasticity in glutamate-dependent excitatory circuits within the motor cortex in BMD patients with intellectual disabilities. RTMS studies may shed new light on the physiological mechanisms of cortical involvement in dystrophinopathies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. True and False Memories, Parietal Cortex, and Confidence Judgments

    Science.gov (United States)

    Urgolites, Zhisen J.; Smith, Christine N.; Squire, Larry R.

    2015-01-01

    Recent studies have asked whether activity in the medial temporal lobe (MTL) and the neocortex can distinguish true memory from false memory. A frequent complication has been that the confidence associated with correct memory judgments (true memory) is typically higher than the confidence associated with incorrect memory judgments (false memory).…

  12. Dysconnection of right parietal and frontal cortex in neglect syndrome

    DEFF Research Database (Denmark)

    Dietz, Martin; Nielsen, Jørgen Feldbæk; Roepstorff, Andreas

    2017-01-01

    A lesion to the right hemisphere of the brain often leads to perceptual neglect of the left side of the sensorium. The fact that lesions to different cortical regions lead to the same symptoms points to neglect as a dysconnection syndrome that may result from the dysconnection of a distributed...... network, rather than a disruption of computation in any particular brain region. To test this hypothesis, we used Bayesian analysis of effective connectivity based on electroencephalographic recordings in patients with left-sided neglect after a right-hemisphere lesion. While age-matched healthy controls...... connectivity in the left hemisphere when stimuli appeared on their right. Crucially, this parieto-frontal feedback connectivity was aggravated in patients with more severe symptoms. In contrast, patients and controls did not show differences in the local connectivity within regions. These findings suggest...

  13. Visual Short-Term Memory Activity in Parietal Lobe Reflects Cognitive Processes beyond Attentional Selection.

    Science.gov (United States)

    Sheremata, Summer L; Somers, David C; Shomstein, Sarah

    2018-02-07

    Visual short-term memory (VSTM) and attention are distinct yet interrelated processes. While both require selection of information across the visual field, memory additionally requires the maintenance of information across time and distraction. VSTM recruits areas within human (male and female) dorsal and ventral parietal cortex that are also implicated in spatial selection; therefore, it is important to determine whether overlapping activation might reflect shared attentional demands. Here, identical stimuli and controlled sustained attention across both tasks were used to ask whether fMRI signal amplitude, functional connectivity, and contralateral visual field bias reflect memory-specific task demands. While attention and VSTM activated similar cortical areas, BOLD amplitude and functional connectivity in parietal cortex differentiated the two tasks. Relative to attention, VSTM increased BOLD amplitude in dorsal parietal cortex and decreased BOLD amplitude in the angular gyrus. Additionally, the tasks differentially modulated parietal functional connectivity. Contrasting VSTM and attention, intraparietal sulcus (IPS) 1-2 were more strongly connected with anterior frontoparietal areas and more weakly connected with posterior regions. This divergence between tasks demonstrates that parietal activation reflects memory-specific functions and consequently modulates functional connectivity across the cortex. In contrast, both tasks demonstrated hemispheric asymmetries for spatial processing, exhibiting a stronger contralateral visual field bias in the left versus the right hemisphere across tasks, suggesting that asymmetries are characteristic of a shared selection process in IPS. These results demonstrate that parietal activity and patterns of functional connectivity distinguish VSTM from more general attention processes, establishing a central role of the parietal cortex in maintaining visual information. SIGNIFICANCE STATEMENT Visual short-term memory (VSTM) and

  14. Counteracting fatigue in multiple sclerosis with right parietal anodal transcranial direct current stimulation

    Directory of Open Access Journals (Sweden)

    Katrin Hanken

    2016-09-01

    Full Text Available Background: Fatigue in multiple sclerosis (MS patients appears to correlate with vigilance decrement as reflected in an increase in reaction time and errors with prolonged time-on-task. Objectives: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. Methods: In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1,5mA was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20min of a 40min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5mA over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. TDCS was delivered for 20min before patients performed a 20min lasting visual vigilance task.Results: Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in reaction time associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation.Conclusions: Anodal tDCS over the right parietal cortex can counteract the increase in reaction times during vigilance performance but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

  15. Counteracting Fatigue in Multiple Sclerosis with Right Parietal Anodal Transcranial Direct Current Stimulation.

    Science.gov (United States)

    Hanken, Katrin; Bosse, Mona; Möhrke, Kim; Eling, Paul; Kastrup, Andreas; Antal, Andrea; Hildebrandt, Helmut

    2016-01-01

    Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time (RT) and errors with prolonged time-on-task. The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1.5 mA) was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20 min of a 40-min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5 mA) over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. tDCS was delivered for 20 min before patients performed a 20-min lasting visual vigilance task. Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in RT associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation. Anodal tDCS over the right parietal cortex can counteract the increase in RTs during vigilance performance, but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

  16. Parietal epithelial cells: their role in health and disease.

    Science.gov (United States)

    Romagnani, Paola

    2011-01-01

    Parietal epithelial cells of Bowman's capsules were first described by Sir William Bowman in 1842 in his paper On the Structure and Use of the Malpighian Bodies of the Kidney [London, Taylor, 1842], but since then their functions have remained poorly understood. A large body of evidence has recently suggested that parietal epithelial cells represent a reservoir of renal progenitors in adult human kidney which generate novel podocytes during childhood and adolescence, and can regenerate injured podocytes. The discovery that parietal epithelial cells represent a potential source for podocyte regeneration suggests that podocyte injury can be repaired. However, recent results also suggest that an abnormal proliferative response of renal progenitors to podocyte injury can generate hyperplastic glomerular lesions that are observed in crescentic glomerulonephritis and other types of glomerular disorders. Taken together, these results establish an entirely novel view that changes the way of thinking about renal physiology and pathophysiology, and suggest that understanding how self-renewal and fate decision of parietal epithelial cells in response to podocyte injury may be perturbed or modulated will be crucial for obtaining novel tools for prevention and treatment of glomerulosclerosis. Copyright © 2011 S. Karger AG, Basel.

  17. Encefalomenigocele atrésico parietal Parietal atresic encephalomeningocele

    Directory of Open Access Journals (Sweden)

    Liliana Rivera Oliva

    2011-09-01

    Full Text Available El encefalocele es una anomalía congénita rara, en la que una porción del encéfalo protruye a través de un orificio craneal (evaginación, generalmente situado en la línea media. Clínicamente se caracteriza por una masa epicraneal, de consistencia blanda, muchas veces acompañada de trastornos psicomotores, convulsiones y trastornos de la visión. Se presenta el caso de un recién nacido con diagnóstico de encefalomeningocele atrésico parietal, intervenido quirúrgicamente y con evolución satisfactoria.The encephalocele is a uncommon congenital anomaly where a portion of encephalon protrudes through a cranial orifice (evagination, generally located in the middle line. Clinically, it is characterized by a soft epicranial mass often accompanied or psychomotor disorders, convulsions and vision disorders. This is the case of a newborn diagnosed with parietal atresic encephalomeningocele operated on with a satisfactory evolution.

  18. Abnormal regional homogeneity in patients with essential tremor revealed by resting-state functional MRI.

    Directory of Open Access Journals (Sweden)

    Weidong Fang

    Full Text Available Essential tremor (ET is one of the most common movement disorders in human adults. It can be characterized as a progressive neurological disorder of which the most recognizable feature is a tremor of the arms or hands that is apparent during voluntary movements such as eating and writing. The pathology of ET remains unclear. Resting-state fMRI (RS-fMRI, as a non-invasive imaging technique, was employed to investigate abnormalities of functional connectivity in ET in the brain. Regional homogeneity (ReHo was used as a metric of RS-fMRI to assess the local functional connectivity abnormality in ET with 20 ET patients and 20 age- and gender-matched healthy controls (HC. The ET group showed decreased ReHo in the anterior and posterior bilateral cerebellar lobes, the bilateral thalamus and the insular lobe, and increased ReHo in the bilateral prefrontal and parietal cortices, the left primary motor cortex and left supplementary motor area. The abnormal ReHo value of ET patients in the bilateral anterior cerebellar lobes and the right posterior cerebellar lobe were negatively correlated with the tremor severity score, while positively correlated with that in the left primary motor cortex. These findings suggest that the abnormality in cerebello-thalamo-cortical motor pathway is involved in tremor generation and propagation, which may be related to motor-related symptoms in ET patients. Meanwhile, the abnormality in the prefrontal and parietal regions may be associated with non-motor symptoms in ET. These findings suggest that the ReHo could be utilized for investigations of functional-pathological mechanism of ET.

  19. Spatial summation in macaque parietal area 7a follows a winner-take-all rule

    NARCIS (Netherlands)

    Oleksiak, Anna; Klink, P. Christiaan; Postma, Albert; van der Ham, Ineke J.M.; Lankheet, Martin J.M.; van Wezel, Richard Jack Anton

    2011-01-01

    While neurons in posterior parietal cortex have been found to signal the presence of a salient stimulus among multiple items in a display, spatial summation within their receptive field in the absence of an attentional bias has never been investigated. This information, however, is indispensable

  20. The Role of the Parietal Lobe in Visual Extinction Studied with Transcranial Magnetic Stimulation

    Science.gov (United States)

    Battelli, Lorella; Alvarez, George A.; Carlson, Thomas; Pascual-Leone, Alvaro

    2009-01-01

    Interhemispheric competition between homologous areas in the human brain is believed to be involved in a wide variety of human behaviors from motor activity to visual perception and particularly attention. For example, patients with lesions in the posterior parietal cortex are unable to selectively track objects in the contralesional side of…

  1. The role of frontal and parietal brain areas in bistable perception

    NARCIS (Netherlands)

    Knapen, T.; Brascamp, J.; Pearson, J.; van Ee, R.; Blake, R.

    2011-01-01

    When sensory input allows for multiple, competing perceptual interpretations, observers' perception can fluctuate over time, which is called bistable perception. Imaging studies in humans have revealed transient responses in a right-lateralized network in the frontal-parietal cortex (rFPC) around

  2. Increased premotor cortex activation in high functioning autism during action observation.

    Science.gov (United States)

    Perkins, Tom J; Bittar, Richard G; McGillivray, Jane A; Cox, Ivanna I; Stokes, Mark A

    2015-04-01

    The mirror neuron (MN) hypothesis of autism has received considerable attention, but to date has produced inconsistent findings. Using functional MRI, participants with high functioning autism or Asperger's syndrome were compared to typically developing individuals (n=12 in each group). Participants passively observed hand gestures that included waving, pointing, and grasping. Concerning the MN network, both groups activated similar regions including prefrontal, inferior parietal and superior temporal regions, with the autism group demonstrating significantly greater activation in the dorsal premotor cortex. Concerning other regions, participants with autism demonstrated increased activity in the anterior cingulate and medial frontal gyrus, and reduced activation in calcarine, cuneus, and middle temporal gyrus. These results suggest that during observation of hand gestures, frontal cortex activation is affected in autism, which we suggest may be linked to abnormal functioning of the MN system. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Origin of parietal podocytes in atubular glomeruli mapped by lineage tracing.

    Science.gov (United States)

    Schulte, Kevin; Berger, Katja; Boor, Peter; Jirak, Peggy; Gelman, Irwin H; Arkill, Kenton P; Neal, Christopher R; Kriz, Wilhelm; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J

    2014-01-01

    Parietal podocytes are fully differentiated podocytes lining Bowman's capsule where normally only parietal epithelial cells (PECs) are found. Parietal podocytes form throughout life and are regularly observed in human biopsies, particularly in atubular glomeruli of diseased kidneys; however, the origin of parietal podocytes is unresolved. To assess the capacity of PECs to transdifferentiate into parietal podocytes, we developed and characterized a novel method for creating atubular glomeruli by electrocoagulation of the renal cortex in mice. Electrocoagulation produced multiple atubular glomeruli containing PECs as well as parietal podocytes that projected from the vascular pole and lined Bowman's capsule. Notably, induction of cell death was evident in some PECs. In contrast, Bowman's capsules of control animals and normal glomeruli of electrocoagulated kidneys rarely contained podocytes. PECs and podocytes were traced by inducible and irreversible genetic tagging using triple transgenic mice (PEC- or Pod-rtTA/LC1/R26R). Examination of serial cryosections indicated that visceral podocytes migrated onto Bowman's capsule via the vascular stalk; direct transdifferentiation from PECs to podocytes was not observed. Similar results were obtained in a unilateral ureter obstruction model and in human diseased kidney biopsies, in which overlap of PEC- or podocyte-specific antibody staining indicative of gradual differentiation did not occur. These results suggest that induction of atubular glomeruli leads to ablation of PECs and subsequent migration of visceral podocytes onto Bowman's capsule, rather than transdifferentiation from PECs to parietal podocytes.

  4. Does shape discrimination by the mouth activate the parietal and occipital lobes? - near-infrared spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Tomonori Kagawa

    Full Text Available A cross-modal association between somatosensory tactile sensation and parietal and occipital activities during Braille reading was initially discovered in tests with blind subjects, with sighted and blindfolded healthy subjects used as controls. However, the neural background of oral stereognosis remains unclear. In the present study, we investigated whether the parietal and occipital cortices are activated during shape discrimination by the mouth using functional near-infrared spectroscopy (fNIRS. Following presentation of the test piece shape, a sham discrimination trial without the test pieces induced posterior parietal lobe (BA7, extrastriate cortex (BA18, BA19, and striate cortex (BA17 activation as compared with the rest session, while shape discrimination of the test pieces markedly activated those areas as compared with the rest session. Furthermore, shape discrimination of the test pieces specifically activated the posterior parietal cortex (precuneus/BA7, extrastriate cortex (BA18, 19, and striate cortex (BA17, as compared with sham sessions without a test piece. We concluded that oral tactile sensation is recognized through tactile/visual cross-modal substrates in the parietal and occipital cortices during shape discrimination by the mouth.

  5. Retinotopic maps and foveal suppression in the visual cortex of amblyopic adults.

    Science.gov (United States)

    Conner, Ian P; Odom, J Vernon; Schwartz, Terry L; Mendola, Janine D

    2007-08-15

    Amblyopia is a developmental visual disorder associated with loss of monocular acuity and sensitivity as well as profound alterations in binocular integration. Abnormal connections in visual cortex are known to underlie this loss, but the extent to which these abnormalities are regionally or retinotopically specific has not been fully determined. This functional magnetic resonance imaging (fMRI) study compared the retinotopic maps in visual cortex produced by each individual eye in 19 adults (7 esotropic strabismics, 6 anisometropes and 6 controls). In our standard viewing condition, the non-tested eye viewed a dichoptic homogeneous mid-level grey stimulus, thereby permitting some degree of binocular interaction. Regions-of-interest analysis was performed for extrafoveal V1, extrafoveal V2 and the foveal representation at the occipital pole. In general, the blood oxygenation level-dependent (BOLD) signal was reduced for the amblyopic eye. At the occipital pole, population receptive fields were shifted to represent more parafoveal locations for the amblyopic eye, compared with the fellow eye, in some subjects. Interestingly, occluding the fellow eye caused an expanded foveal representation for the amblyopic eye in one early-onset strabismic subject with binocular suppression, indicating real-time cortical remapping. In addition, a few subjects actually showed increased activity in parietal and temporal cortex when viewing with the amblyopic eye. We conclude that, even in a heterogeneous population, abnormal early visual experience commonly leads to regionally specific cortical adaptations.

  6. Multimodal responses induced by cortical stimulation of the parietal lobe: a stereo-electroencephalography study.

    Science.gov (United States)

    Balestrini, Simona; Francione, Stefano; Mai, Roberto; Castana, Laura; Casaceli, Giuseppe; Marino, Daniela; Provinciali, Leandro; Cardinale, Francesco; Tassi, Laura

    2015-09-01

    The functional complexity of the parietal lobe still represents a challenge for neurophysiological and functional neuroimaging studies. While the somatosensory functions of the anterior parietal cortex are well established, the posterior parietal cortex has a relevant role in processing the sensory information, including visuo-spatial perception, visual attention, visuo-motor transformations and other complex and not completely understood functions. We retrospectively analysed all the clinical manifestations induced by intracerebral bipolar electrical stimulation in 172 patients suffering from drug-resistant focal epilepsy (mean age 25.6, standard deviation 11.6; 44% females and 56% males) with at least one electrode stereotactically implanted in the parietal cortex. A total of 1186 electrical stimulations were included in the analysis, of which 88 were subsequently excluded because of eliciting pathological electric activity or inducing ictal symptomatology. In the dominant parietal lobe, clinical responses were observed for 56 (25%) of the low-frequency stimulations and for 76 (50%) of the high-frequency stimulations. In the non-dominant parietal lobe, 111 (27%) low-frequency and 176 (55%) high-frequency stimulations were associated with a clinical response. Body scheme alteration was the only clinical effect showing a lateralization, as they were evoked only in the non-dominant hemisphere. The occurrence of somatosensory sensations, motor symptoms, dysarthria and multimodal responses were significantly associated with stimulation of the postcentral gyrus (odds ratio: 5.83, P < 0.001; odds ratio: 8.77, P < 0.001; odds ratio: 5.44, P = 0.011; odds ratio: 8.33, P = 0.006; respectively). Stimulation of the intraparietal sulcus was associated with the occurrence of sensory illusions or hallucinations (odds ratio: 8.68, P < 0.001) and eyeball/eyelid movements or sensations (odds ratio: 4.35, P = 0.047). To our knowledge, this is the only currently available complete

  7. Regional cerebral blood flow abnormalities in late-life depression. Relation to refractoriness and chronification

    International Nuclear Information System (INIS)

    Awata, Shuichi; Konno, Michiko; Sato, Mitsumoto; Ito, Hiroshi; Ono, Shuichi; Kawashima, Ryuta; Fukuda, Hiroshi

    1998-01-01

    We examined patterns of regional cerebral blood flow (rCBF) abnormalities in 18 patients with major depressive disorder in late life using single photon emission computed tomography (SPECT) and 99m Tc-hexamethyl-propylenamine oxime ( 99m Tc-HMPAO). Compared with 13 age-matched controls, relative rCBF was significantly decreased bilaterally in the anterior cingulate gyrus, the prefrontal cortex, the temporal cortex, the parietal cortex, the hippocampus and the caudate nucleus. However, it was not correlated with the severity of depression or global cognitive dysfunction. In 10 patients with a prolonged depressive episode or prolonged residual symptoms (the refractory subgroup), robust and extensive decreases in rCBF were found compared with controls and the rCBF decreased significantly in the anterior cingulate gyrus and the prefrontal cortex compared with that in the non-refractory subgroup. In the non-reflactory subgroup, rCBF decreased significantly in the caudate nucleus and tended to decrease in the anterior cingulate gyrus compared with controls. These findings indicate that dysfunction of the limbic system, the cerebral association cortex and the caudate nucleus may be implicated in late-life depression and that robust and extensive hypoperfusion, especially in the anterior cingulate and the prefrontal regions, may relate to refractoriness or chronification of depression. (author). 60 refs

  8. Regional cerebral blood flow abnormalities in late-life depression. Relation to refractoriness and chronification

    Energy Technology Data Exchange (ETDEWEB)

    Awata, Shuichi; Konno, Michiko; Sato, Mitsumoto [Tohoku Univ., Sendai (Japan). School of Medicine; Ito, Hiroshi; Ono, Shuichi; Kawashima, Ryuta; Fukuda, Hiroshi

    1998-02-01

    We examined patterns of regional cerebral blood flow (rCBF) abnormalities in 18 patients with major depressive disorder in late life using single photon emission computed tomography (SPECT) and {sup 99m}Tc-hexamethyl-propylenamine oxime ({sup 99m}Tc-HMPAO). Compared with 13 age-matched controls, relative rCBF was significantly decreased bilaterally in the anterior cingulate gyrus, the prefrontal cortex, the temporal cortex, the parietal cortex, the hippocampus and the caudate nucleus. However, it was not correlated with the severity of depression or global cognitive dysfunction. In 10 patients with a prolonged depressive episode or prolonged residual symptoms (the refractory subgroup), robust and extensive decreases in rCBF were found compared with controls and the rCBF decreased significantly in the anterior cingulate gyrus and the prefrontal cortex compared with that in the non-refractory subgroup. In the non-reflactory subgroup, rCBF decreased significantly in the caudate nucleus and tended to decrease in the anterior cingulate gyrus compared with controls. These findings indicate that dysfunction of the limbic system, the cerebral association cortex and the caudate nucleus may be implicated in late-life depression and that robust and extensive hypoperfusion, especially in the anterior cingulate and the prefrontal regions, may relate to refractoriness or chronification of depression. (author). 60 refs.

  9. Optimized gamma synchronization enhances functional binding of fronto-parietal cortices in mathematically gifted adolescents during deductive reasoning

    Directory of Open Access Journals (Sweden)

    Li eZhang

    2014-06-01

    Full Text Available As enhanced fronto-parietal network has been suggested to support reasoning ability of math-gifted adolescents, the main goal of this EEG source analysis is to investigate the temporal binding of the gamma-band (30-60Hz synchronization between frontal and parietal cortices in adolescents with exceptional mathematical ability, including the functional connectivity of gamma neurocognitive network, the temporal dynamics of fronto-parietal network (phase-locking durations and network lability in time domain, and the self-organized criticality of synchronizing oscillation. Compared with the average-ability subjects, the math-gifted adolescents show a highly integrated fronto-parietal network due to distant gamma phase-locking oscillations, which is indicated by lower modularity of the global network topology, more connector bridges between the frontal and parietal cortices and less connector hubs in the sensorimotor cortex. The time-domain analysis finds that, while maintaining more stable phase dynamics of the fronto-parietal coupling, the math-gifted adolescents are characterized by more extensive fronto-parietal connection reconfiguration. The results from sample fitting in the power-law model further find that the phase-locking durations in the math-gifted brain abides by a wider interval of the power-law distribution. This phase-lock distribution mechanism could represent a relatively optimized pattern for the functional binding of frontal-parietal network, which underlies stable fronto-parietal connectivity and increases flexibility of timely network reconfiguration.

  10. Parietal podocytes in normal human glomeruli.

    Science.gov (United States)

    Bariety, Jean; Mandet, Chantal; Hill, Gary S; Bruneval, Patrick

    2006-10-01

    Although parietal podocytes along the Bowman's capsule have been described by electron microscopy in the normal human kidney, their molecular composition remains unknown. Ten human normal kidneys that were removed for cancer were assessed for the presence and the extent of parietal podocytes along the Bowman's capsule. The expression of podocyte-specific proteins (podocalyxin, glomerular epithelial protein-1, podocin, nephrin, synaptopodin, and alpha-actinin-4), podocyte synthesized proteins (vascular endothelial growth factor and novH), transcription factors (WT1 and PAX2), cyclin-dependent kinase inhibitor p57, and intermediate filaments (cytokeratins and vimentin) was tested. In addition, six normal fetal kidneys were studied to track the ontogeny of parietal podocytes. The podocyte protein labeling detected parietal podocytes in all of the kidneys, was found in 76.6% on average of Bowman's capsule sections, and was prominent at the vascular pole. WT1 and p57 were expressed in some parietal cells, whereas PAX2 was present in all or most of them, so some parietal cells coexpressed WT1 and PAX2. Furthermore, parietal podocytes coexpressed WT1 and podocyte proteins. Cytokeratin-positive cells covered a variable part of the capsule and did not express podocyte proteins. Tuft-capsular podocyte bridges were present in 15.5 +/- 3.7% of the glomerular sections. Parietal podocytes often covered the juxtaglomerular arterioles and were present within the extraglomerular mesangium. Parietal podocytes were present in fetal kidneys. Parietal podocytes that express the same epitopes as visceral podocytes do exist along Bowman's capsule in the normal adult kidney. They are a constitutive cell type of the Bowman's capsule. Therefore, their role in physiology and pathology should be investigated.

  11. Parietal Lobe Volume Deficits in Adolescents with Schizophrenia and Adolescents with Cannabis Use Disorders

    Science.gov (United States)

    Kumra, Sanjiv; Robinson, Paul; Tambyraja, Rabindra; Jensen, Daniel; Schimunek, Caroline; Houri, Alaa; Reis, Tiffany; Lim, Kelvin

    2012-01-01

    Objective: In early-onset schizophrenia (EOS), the earliest structural brain volumetric abnormalities appear in the parietal cortices. Early exposure to cannabis may represent an environmental risk factor for developing schizophrenia. This study characterized cerebral cortical gray matter structure in adolescents in regions of interest (ROIs) that…

  12. Connectivity changes underlying neurofeedback training of visual cortex activity.

    Directory of Open Access Journals (Sweden)

    Frank Scharnowski

    Full Text Available Neurofeedback based on real-time functional magnetic resonance imaging (fMRI is a new approach that allows training of voluntary control over regionally specific brain activity. However, the neural basis of successful neurofeedback learning remains poorly understood. Here, we assessed changes in effective brain connectivity associated with neurofeedback training of visual cortex activity. Using dynamic causal modeling (DCM, we found that training participants to increase visual cortex activity was associated with increased effective connectivity between the visual cortex and the superior parietal lobe. Specifically, participants who learned to control activity in their visual cortex showed increased top-down control of the superior parietal lobe over the visual cortex, and at the same time reduced bottom-up processing. These results are consistent with efficient employment of top-down visual attention and imagery, which were the cognitive strategies used by participants to increase their visual cortex activity.

  13. Modulation of fronto-parietal connections during the rubber hand illusion

    DEFF Research Database (Denmark)

    Karabanov, Anke Ninija; Ritterband-Rosenbaum, Anina; Christensen, Mark Schram

    2017-01-01

    Accumulating evidence suggests that parieto-frontal connections play a role in adjusting body ownership during the Rubber Hand Illusion (RHI). Using a motor version of the rubber hand illusion paradigm, we applied single-site and dual-site transcranial magnetic stimulation (TMS) to investigate...... and during three RHI conditions: a) agency and ownership, b) agency but no ownership and c) neither agency nor ownership. Parietal-motor communication differed among experimental conditions. The induction of action ownership was associated with an inhibitory parietal-to-motor connectivity, which...... cortico-spinal and parietal-frontal connectivity during perceived rubber hand ownership. Healthy volunteers received a conditioning TMS pulse over left anterior intraparietal sulcus (aIPS) and a test TMS pulse over left primary motor cortex (M1). Motor Evoked Potentials (MEPs) were recorded at rest...

  14. Fractionation of parietal function in bistable perception probed with concurrent TMS-EEG.

    Science.gov (United States)

    Schauer, Georg; Chang, Acer; Schwartzman, David; Rae, Charlotte L; Iriye, Heather; Seth, Anil K; Kanai, Ryota

    2016-08-16

    When visual input has conflicting interpretations, conscious perception can alternate spontaneously between these possible interpretations. This is called bistable perception. Previous neuroimaging studies have indicated the involvement of two right parietal areas in resolving perceptual ambiguity (ant-SPLr and post-SPLr). Transcranial magnetic stimulation (TMS) studies that selectively interfered with the normal function of these regions suggest that they play opposing roles in this type of perceptual switch. In the present study, we investigated this fractionation of parietal function by use of combined TMS with electroencephalography (EEG). Specifically, while participants viewed either a bistable stimulus, a replay stimulus, or resting-state fixation, we applied single pulse TMS to either location independently while simultaneously recording EEG. Combined with participant's individual structural magnetic resonance imaging (MRI) scans, this dataset allows for complex analyses of the effect of TMS on neural time series data, which may further elucidate the causal role of the parietal cortex in ambiguous perception.

  15. Parietal theta burst TMS: Functional fractionation observed during bistable perception not evident in attention tasks.

    Science.gov (United States)

    Schauer, Georg; Kanai, Ryota; Brascamp, Jan W

    2016-02-01

    When visual input is ambiguous, perception spontaneously alternates between interpretations: bistable perception. Studies have identified two distinct sites near the right intraparietal sulcus where inhibitory transcranial magnetic stimulation (TMS) affects the frequency of occurrence of these alternations, but strikingly with opposite directions of effect for the two sites. Lesion and TMS studies on spatial and sustained attention have also indicated a parcellation of right parietal cortex, into areas serving distinct attentional functions. We used the exact TMS procedure previously employed to affect bistable perception, yet measured its effect on spatial and sustained attention tasks. Although there was a trend for TMS to affect performance, trends were consistently similar for both parietal sites, with no indication of opposite effects. We interpret this as signifying that the previously observed parietal fractionation of function regarding the perception of ambiguous stimuli is not due to TMS-induced modification of spatial or sustained attention. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Abnormal Brain Responses to Action Observation in Complex Regional Pain Syndrome.

    Science.gov (United States)

    Hotta, Jaakko; Saari, Jukka; Koskinen, Miika; Hlushchuk, Yevhen; Forss, Nina; Hari, Riitta

    2017-03-01

    Patients with complex regional pain syndrome (CRPS) display various abnormalities in central motor function, and their pain is intensified when they perform or just observe motor actions. In this study, we examined the abnormalities of brain responses to action observation in CRPS. We analyzed 3-T functional magnetic resonance images from 13 upper limb CRPS patients (all female, ages 31-58 years) and 13 healthy, age- and sex-matched control subjects. The functional magnetic resonance imaging data were acquired while the subjects viewed brief videos of hand actions shown in the first-person perspective. A pattern-classification analysis was applied to characterize brain areas where the activation pattern differed between CRPS patients and healthy subjects. Brain areas with statistically significant group differences (q frontal gyrus, secondary somatosensory cortex, inferior parietal lobule, orbitofrontal cortex, and thalamus. Our findings indicate that CRPS impairs action observation by affecting brain areas related to pain processing and motor control. This article shows that in CRPS, the observation of others' motor actions induces abnormal neural activity in brain areas essential for sensorimotor functions and pain. These results build the cerebral basis for action-observation impairments in CRPS. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

  17. Abnormal resting state effective connectivity within the default mode network in major depressive disorder: A spectral dynamic causal modeling study.

    Science.gov (United States)

    Li, Liang; Li, Baojuan; Bai, Yuanhan; Liu, Wenlei; Wang, Huaning; Leung, Hoi-Chung; Tian, Ping; Zhang, Linchuan; Guo, Fan; Cui, Long-Biao; Yin, Hong; Lu, Hongbing; Tan, Qingrong

    2017-07-01

    Understanding the neural basis underlying major depressive disorder (MDD) is essential for the diagnosis and treatment of this mental disorder. Aberrant activation and functional connectivity of the default mode network (DMN) have been consistently found in patients with MDD. It is not known whether effective connectivity within the DMN is altered in MDD. The primary object of this study is to investigate the effective connectivity within the DMN during resting state in MDD patients before and after eight weeks of antidepressant treatment. We defined four regions of the DMN (medial frontal cortex, posterior cingulate cortex, left parietal cortex, and right parietal cortex) for each participant using a group independent component analysis. The coupling parameters reflecting the causal interactions among the DMN regions were estimated using spectral dynamic causal modeling (DCM). Twenty-seven MDD patients and 27 healthy controls were included in the statistical analysis. Our results showed declined influences from the left parietal cortex to other DMN regions in the pre-treatment patients as compared with healthy controls. After eight weeks of treatment, the influence from the right parietal cortex to the posterior cingulate cortex significantly decreased. These findings suggest that the reduced excitatory causal influence of the left parietal cortex is the key alteration of the DMN in patients with MDD, and the disrupted causal influences that parietal cortex exerts on the posterior cingulate cortex is responsive to antidepressant treatment.

  18. Effects of Preweaning Polysensorial Enrichment upon Development of the Parietal Cortical Plate of Undernourished Rats: A Stereological Study

    OpenAIRE

    González, Héctor; Adaro, Luis; Hernández, Alejandro; Fernández, Víctor

    2014-01-01

    This investigation was undertaken in order to quantify the effects of early polysensorial enrichment on the development of cortical pyramids, located in the parietal cortex of rats simultaneously submitted to protein-energy undernutrition. A short period of stimulation during suckling significantly decreases the cellular density in the cortical plate (phylogenetic-ontogenetic evolutionary index). Results suggest that the cerebral cortex develops according to a sophisticated neuronal network, ...

  19. Potential role of monkey inferior parietal neurons coding action semantic equivalences as precursors of parts of speech.

    Science.gov (United States)

    Yamazaki, Yumiko; Yokochi, Hiroko; Tanaka, Michio; Okanoya, Kazuo; Iriki, Atsushi

    2010-01-01

    The anterior portion of the inferior parietal cortex possesses comprehensive representations of actions embedded in behavioural contexts. Mirror neurons, which respond to both self-executed and observed actions, exist in this brain region in addition to those originally found in the premotor cortex. We found that parietal mirror neurons responded differentially to identical actions embedded in different contexts. Another type of parietal mirror neuron represents an inverse and complementary property of responding equally to dissimilar actions made by itself and others for an identical purpose. Here, we propose a hypothesis that these sets of inferior parietal neurons constitute a neural basis for encoding the semantic equivalence of various actions across different agents and contexts. The neurons have mirror neuron properties, and they encoded generalization of agents, differentiation of outcomes, and categorization of actions that led to common functions. By integrating the activities of these mirror neurons with various codings, we further suggest that in the ancestral primates' brains, these various representations of meaningful action led to the gradual establishment of equivalence relations among the different types of actions, by sharing common action semantics. Such differential codings of the components of actions might represent precursors to the parts of protolanguage, such as gestural communication, which are shared among various members of a society. Finally, we suggest that the inferior parietal cortex serves as an interface between this action semantics system and other higher semantic systems, through common structures of action representation that mimic language syntax.

  20. Thalamic and parietal brain morphology predicts auditory category learning.

    Science.gov (United States)

    Scharinger, Mathias; Henry, Molly J; Erb, Julia; Meyer, Lars; Obleser, Jonas

    2014-01-01

    Auditory categorization is a vital skill involving the attribution of meaning to acoustic events, engaging domain-specific (i.e., auditory) as well as domain-general (e.g., executive) brain networks. A listener's ability to categorize novel acoustic stimuli should therefore depend on both, with the domain-general network being particularly relevant for adaptively changing listening strategies and directing attention to relevant acoustic cues. Here we assessed adaptive listening behavior, using complex acoustic stimuli with an initially salient (but later degraded) spectral cue and a secondary, duration cue that remained nondegraded. We employed voxel-based morphometry (VBM) to identify cortical and subcortical brain structures whose individual neuroanatomy predicted task performance and the ability to optimally switch to making use of temporal cues after spectral degradation. Behavioral listening strategies were assessed by logistic regression and revealed mainly strategy switches in the expected direction, with considerable individual differences. Gray-matter probability in the left inferior parietal lobule (BA 40) and left precentral gyrus was predictive of "optimal" strategy switch, while gray-matter probability in thalamic areas, comprising the medial geniculate body, co-varied with overall performance. Taken together, our findings suggest that successful auditory categorization relies on domain-specific neural circuits in the ascending auditory pathway, while adaptive listening behavior depends more on brain structure in parietal cortex, enabling the (re)direction of attention to salient stimulus properties. © 2013 Published by Elsevier Ltd.

  1. Functional activity of the sensorimotor cortex and cerebellum relates to cervical dystonia symptoms.

    Science.gov (United States)

    Burciu, Roxana G; Hess, Christopher W; Coombes, Stephen A; Ofori, Edward; Shukla, Priyank; Chung, Jae Woo; McFarland, Nikolaus R; Wagle Shukla, Aparna; Okun, Michael S; Vaillancourt, David E

    2017-09-01

    Cervical dystonia (CD) is the most common type of focal dystonia, causing abnormal movements of the neck and head. In this study, we used noninvasive imaging to investigate the motor system of patients with CD and uncover the neural correlates of dystonic symptoms. Furthermore, we examined whether a commonly prescribed anticholinergic medication in CD has an effect on the dystonia-related brain abnormalities. Participants included 16 patients with CD and 16 healthy age-matched controls. We collected functional MRI scans during a force task previously shown to extensively engage the motor system, and diffusion and T1-weighted MRI scans from which we calculated free-water and brain tissue densities. The dystonia group was also scanned ca. 2 h after a 2-mg dose of trihexyphenidyl. Severity of dystonia was assessed pre- and post-drug using the Burke-Fahn-Marsden Dystonia Rating Scale. Motor-related activity in CD was altered relative to controls in the primary somatosensory cortex, cerebellum, dorsal premotor and posterior parietal cortices, and occipital cortex. Most importantly, a regression model showed that increased severity of symptoms was associated with decreased functional activity of the somatosensory cortex and increased activity of the cerebellum. Structural imaging measures did not differ between CD and controls. The single dose of trihexyphenidyl altered the fMRI signal in the somatosensory cortex but not in the cerebellum. Symptom severity was not significantly reduced post-treatment. Findings show widespread changes in functional brain activity in CD and most importantly that dystonic symptoms relate to disrupted activity in the somatosensory cortex and cerebellum. Hum Brain Mapp 38:4563-4573, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Cortical Abnormalities Associated With Pediatric and Adult Obsessive-Compulsive Disorder: Findings From the ENIGMA Obsessive-Compulsive Disorder Working Group.

    Science.gov (United States)

    Boedhoe, Premika S W; Schmaal, Lianne; Abe, Yoshinari; Alonso, Pino; Ameis, Stephanie H; Anticevic, Alan; Arnold, Paul D; Batistuzzo, Marcelo C; Benedetti, Francesco; Beucke, Jan C; Bollettini, Irene; Bose, Anushree; Brem, Silvia; Calvo, Anna; Calvo, Rosa; Cheng, Yuqi; Cho, Kang Ik K; Ciullo, Valentina; Dallaspezia, Sara; Denys, Damiaan; Feusner, Jamie D; Fitzgerald, Kate D; Fouche, Jean-Paul; Fridgeirsson, Egill A; Gruner, Patricia; Hanna, Gregory L; Hibar, Derrek P; Hoexter, Marcelo Q; Hu, Hao; Huyser, Chaim; Jahanshad, Neda; James, Anthony; Kathmann, Norbert; Kaufmann, Christian; Koch, Kathrin; Kwon, Jun Soo; Lazaro, Luisa; Lochner, Christine; Marsh, Rachel; Martínez-Zalacaín, Ignacio; Mataix-Cols, David; Menchón, José M; Minuzzi, Luciano; Morer, Astrid; Nakamae, Takashi; Nakao, Tomohiro; Narayanaswamy, Janardhanan C; Nishida, Seiji; Nurmi, Erika; O'Neill, Joseph; Piacentini, John; Piras, Fabrizio; Piras, Federica; Reddy, Y C Janardhan; Reess, Tim J; Sakai, Yuki; Sato, Joao R; Simpson, H Blair; Soreni, Noam; Soriano-Mas, Carles; Spalletta, Gianfranco; Stevens, Michael C; Szeszko, Philip R; Tolin, David F; van Wingen, Guido A; Venkatasubramanian, Ganesan; Walitza, Susanne; Wang, Zhen; Yun, Je-Yeon; Thompson, Paul M; Stein, Dan J; van den Heuvel, Odile A

    2018-05-01

    Brain imaging studies of structural abnormalities in OCD have yielded inconsistent results, partly because of limited statistical power, clinical heterogeneity, and methodological differences. The authors conducted meta- and mega-analyses comprising the largest study of cortical morphometry in OCD ever undertaken. T 1 -weighted MRI scans of 1,905 OCD patients and 1,760 healthy controls from 27 sites worldwide were processed locally using FreeSurfer to assess cortical thickness and surface area. Effect sizes for differences between patients and controls, and associations with clinical characteristics, were calculated using linear regression models controlling for age, sex, site, and intracranial volume. In adult OCD patients versus controls, we found a significantly lower surface area for the transverse temporal cortex and a thinner inferior parietal cortex. Medicated adult OCD patients also showed thinner cortices throughout the brain. In pediatric OCD patients compared with controls, we found significantly thinner inferior and superior parietal cortices, but none of the regions analyzed showed significant differences in surface area. However, medicated pediatric OCD patients had lower surface area in frontal regions. Cohen's d effect sizes varied from -0.10 to -0.33. The parietal cortex was consistently implicated in both adults and children with OCD. More widespread cortical thickness abnormalities were found in medicated adult OCD patients, and more pronounced surface area deficits (mainly in frontal regions) were found in medicated pediatric OCD patients. These cortical measures represent distinct morphological features and may be differentially affected during different stages of development and illness, and possibly moderated by disease profile and medication.

  3. Frontal and parietal cortical interactions with distributed visual representations during selective attention and action selection.

    Science.gov (United States)

    Nelissen, Natalie; Stokes, Mark; Nobre, Anna C; Rushworth, Matthew F S

    2013-10-16

    Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity.

  4. Frontal and Parietal Cortical Interactions with Distributed Visual Representations during Selective Attention and Action Selection

    Science.gov (United States)

    Stokes, Mark; Nobre, Anna C.; Rushworth, Matthew F. S.

    2013-01-01

    Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity. PMID:24133250

  5. Counteracting fatigue in multiple sclerosis with right parietal anodal transcranial direct current stimulation

    OpenAIRE

    Katrin Hanken; Katrin Hanken; Mona Bosse; Kim Möhrke; Paul Eling; Andreas Kastrup; Andrea Antal; Helmut Hildebrandt; Helmut Hildebrandt

    2016-01-01

    Background: Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time and errors with prolonged time-on-task. Objectives: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. Methods: In study I, a randomized double-blind placebo-controlled study, anoda...

  6. Counteracting Fatigue in Multiple Sclerosis with Right Parietal Anodal Transcranial Direct Current Stimulation

    OpenAIRE

    Hanken, Katrin; Bosse, Mona; M?hrke, Kim; Eling, Paul; Kastrup, Andreas; Antal, Andrea; Hildebrandt, Helmut

    2016-01-01

    BACKGROUND: Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time (RT) and errors with prolonged time-on-task. OBJECTIVES: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. METHODS: In study I, a randomized double-blind placebo-controll...

  7. Metabolic Hyperactivity of the Medial Posterior Parietal Lobes in Psychogenic Tremor

    Directory of Open Access Journals (Sweden)

    Peter Hedera

    2012-05-01

    Full Text Available Background: The pathophysiology of psychogenic movement disorders, including psychogenic tremor (PT, is only emerging. Case Report: This is a single case report of a patient who met diagnostic criteria for PT. He underwent positron emission tomography (PET of brain with 18F-deoxyglucose at resting state. His PET study showed symmetrically increased 18F-deoxyglucose uptake in both posterior medial parietal lobes. There was no corresponding abnormality on structural imaging. Discussion: Hypermetabolism of the medial aspects of posterior parietal lobes bilaterally may reflect abnormal activity of sensory integration that is important in the pathogenesis of PT. This further supports the idea that non-organic movement disorders may be associated with detectable functional brain abnormalities.

  8. Sensory-parietal cortical stimulation improves motor recovery in severe capsular infarct.

    Science.gov (United States)

    Kim, Ra Gyung; Cho, Jongwook; Ree, Jinkyue; Kim, Hyung-Sun; Rosa-Neto, Pedro; Kim, Jin-Myung; Lee, Min-Cheol; Kim, Hyoung-Ihl

    2016-12-01

    The prevalence of subcortical white matter strokes in elderly patients is on the rise, but these patients show mixed responses to conventional rehabilitative interventions. To examine whether cortical electrical stimulation can promote motor recovery after white matter stroke, we delivered stimulation to a small or wide region of sensory-parietal cortex for two weeks in a rodent model of circumscribed subcortical capsular infarct. The sham-operated group (SOG) showed persistent and severe motor impairments together with decreased activation in bilateral sensorimotor cortices and striatum. In contrast, sensory-parietal cortex stimulation significantly improved motor recovery: final recovery levels were 72.9% of prelesion levels in the wide stimulation group (WSG) and 37% of prelesion levels in the small stimulation group (SSG). The microPET imaging showed reversal of cortical diaschisis in both groups: in both hemispheres for the WSG, and in the hemisphere ipsilateral to stimulation in the SSG. In addition, we observed activation of the corpus callosum and subcortical corticostriatal structures after stimulation. The results from the c-Fos mapping study were grossly consistent with the microPET imaging. Sensory-parietal cortex stimulation may therefore be a useful strategy for overcoming the limits of rehabilitative training in patients with severe forms of subcortical capsular infarct. © The Author(s) 2015.

  9. The role of prefrontal and parietal cortices in esthetic appreciation of representational and abstract art: a TMS study.

    Science.gov (United States)

    Cattaneo, Zaira; Lega, Carlotta; Gardelli, Chiara; Merabet, Lotfi B; Cela-Conde, Camilo J; Nadal, Marcos

    2014-10-01

    To explain the biological foundations of art appreciation is to explain one of our species' distinctive traits. Previous neuroimaging and electrophysiological studies have pointed to the prefrontal and the parietal cortex as two critical regions mediating esthetic appreciation of visual art. In this study, we applied transcranial magnetic stimulation (TMS) over the left prefrontal cortex and the right posterior parietal cortex while participants were evaluating whether they liked, and by how much, a particular painting. By depolarizing cell membranes in the targeted regions, TMS transiently interferes with the activity of specific cortical areas, which allows clarifying their role in a given task. Our results show that both regions play a fundamental role in mediating esthetic appreciation. Critically though, the effects of TMS varied depending on the type of art considered (i.e. representational vs. abstract) and on participants' a-priori inclination toward one or the other. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Abnormal Intrinsic Functional Hubs in Severe Male Obstructive Sleep Apnea: Evidence from a Voxel-Wise Degree Centrality Analysis.

    Science.gov (United States)

    Li, Haijun; Li, Lan; Shao, Yi; Gong, Honghan; Zhang, Wei; Zeng, Xianjun; Ye, Chenglong; Nie, Si; Chen, Liting; Peng, Dechang

    2016-01-01

    Obstructive sleep apnea (OSA) has been associated with changes in brain structure and regional function in certain brain areas. However, the functional features of network organization in the whole brain remain largely uncertain. The purpose of this study was to identify the OSA-related spatial centrality distribution of the whole brain functional network and to investigate the potential altered intrinsic functional hubs. Forty male patients with newly confirmed severe OSA on polysomnography, and well-matched good sleepers, participated in this study. All participants underwent a resting-state functional MRI scan and clinical and cognitive evaluation. Voxel-wise degree centrality (DC) was measured across the whole brain, and group difference in DC was compared. The relationship between the abnormal DC value and clinical variables was assessed using a linear correlation analysis. Remarkably similar spatial distributions of the functional hubs (high DC) were found in both groups. However, OSA patients exhibited a pattern of significantly reduced regional DC in the left middle occipital gyrus, posterior cingulate cortex, left superior frontal gyrus, and bilateral inferior parietal lobule, and DC was increased in the right orbital frontal cortex, bilateral cerebellum posterior lobes, and bilateral lentiform nucleus, including the putamen, extending to the hippocampus, and the inferior temporal gyrus, which overlapped with the functional hubs. Furthermore, a linear correlation analysis revealed that the DC value in the posterior cingulate cortex and left superior frontal gyrus were positively correlated with Montreal cognitive assessment scores, The DC value in the left middle occipital gyrus and bilateral inferior parietal lobule were negatively correlated with apnea-hypopnea index and arousal index in OSA patients. Our findings suggest that OSA patients exhibited specific abnormal intrinsic functional hubs including relatively reduced and increased DC. This expands

  11. An enlarged parietal foramen in the late archaic Xujiayao 11 neurocranium from Northern China, and rare anomalies among Pleistocene Homo.

    Science.gov (United States)

    Wu, Xiu-Jie; Xing, Song; Trinkaus, Erik

    2013-01-01

    We report here a neurocranial abnormality previously undescribed in Pleistocene human fossils, an enlarged parietal foramen (EPF) in the early Late Pleistocene Xujiayao 11 parietal bones from the Xujiayao (Houjiayao) site, northern China. Xujiayao 11 is a pair of partial posteromedial parietal bones from an adult. It exhibits thick cranial vault bones, arachnoid granulations, a deviated posterior sagittal suture, and a unilateral (right) parietal lacuna with a posteriorly-directed and enlarged endocranial vascular sulcus. Differential diagnosis indicates that the perforation is a congenital defect, an enlarged parietal foramen, commonly associated with cerebral venous and cranial vault anomalies. It was not lethal given the individual's age-at-death, but it may have been associated with secondary neurological deficiencies. The fossil constitutes the oldest evidence in human evolution of this very rare condition (a single enlarged parietal foramen). In combination with developmental and degenerative abnormalities in other Pleistocene human remains, it suggests demographic and survival patterns among Pleistocene Homo that led to an elevated frequency of conditions unknown or rare among recent humans.

  12. An enlarged parietal foramen in the late archaic Xujiayao 11 neurocranium from Northern China, and rare anomalies among Pleistocene Homo.

    Directory of Open Access Journals (Sweden)

    Xiu-Jie Wu

    Full Text Available We report here a neurocranial abnormality previously undescribed in Pleistocene human fossils, an enlarged parietal foramen (EPF in the early Late Pleistocene Xujiayao 11 parietal bones from the Xujiayao (Houjiayao site, northern China. Xujiayao 11 is a pair of partial posteromedial parietal bones from an adult. It exhibits thick cranial vault bones, arachnoid granulations, a deviated posterior sagittal suture, and a unilateral (right parietal lacuna with a posteriorly-directed and enlarged endocranial vascular sulcus. Differential diagnosis indicates that the perforation is a congenital defect, an enlarged parietal foramen, commonly associated with cerebral venous and cranial vault anomalies. It was not lethal given the individual's age-at-death, but it may have been associated with secondary neurological deficiencies. The fossil constitutes the oldest evidence in human evolution of this very rare condition (a single enlarged parietal foramen. In combination with developmental and degenerative abnormalities in other Pleistocene human remains, it suggests demographic and survival patterns among Pleistocene Homo that led to an elevated frequency of conditions unknown or rare among recent humans.

  13. Central and peripheral components of writing critically depend on a defined area of the dominant superior parietal gyrus.

    Science.gov (United States)

    Magrassi, Lorenzo; Bongetta, Daniele; Bianchini, Simonetta; Berardesca, Marta; Arienta, Cesare

    2010-07-30

    Classical neuropsychological models of writing separate central (linguistic) processes common to oral spelling, writing and typing from peripheral (motor) processes that are modality specific. Damage to the left superior parietal gyrus, an area of the cortex involved in peripheral processes specific to handwriting, should generate distorted graphemes but not misspelled words, while damage to other areas of the cortex like the frontal lobe should produce alterations in written and oral spelling without distorted graphemes. We describe the clinical and neuropsychological features of a patient with combined agraphia for handwriting and typewriting bearing a small glioblastoma in the left parietal lobe. His agraphia resolved after antiedema therapy and we tested by bipolar cortical stimulation his handwriting abilities during an awake neurosurgical procedure. We found that we could reversibly re-induce the same defects of writing by stimulating during surgery a limited area of the superior parietal gyrus in the same patient and in an independent patient that was never agraphic before the operation. In those patients stimulation caused spelling errors, poorly formed letters and in some cases a complete cessation of writing with minimal or no effects on oral spelling. Our results suggest that stimulating a specific area in the superior parietal gyrus we can generate different patterns of agraphia. Moreover, our findings also suggest that some of the central processes specific for typing and handwriting converge with motor processes at least in the limited portion of the superior parietal gyrus we mapped in our patients. Copyright 2010 Elsevier B.V. All rights reserved.

  14. Deficits in visual search for conjunctions of motion and form after parietal damage but with spared hMT+/V5.

    Science.gov (United States)

    Dent, Kevin; Lestou, Vaia; Humphreys, Glyn W

    2010-02-01

    It has been argued that area hMT+/V5 in humans acts as a motion filter, enabling targets defined by a conjunction of motion and form to be efficiently selected. We present data indicating that (a) damage to parietal cortex leads to a selective problem in processing motion-form conjunctions, and (b) that the presence of a structurally and functional intact hMT+/V5 is not sufficient for efficient search for motion-form conjunctions. We suggest that, in addition to motion-processing areas (e.g., hMT+/V5), the posterior parietal cortex is necessary for efficient search with motion-form conjunctions, so that damage to either brain region may bring about deficits in search. We discuss the results in terms of the involvement of the posterior parietal cortex in the top-down guidance of search or in the binding of motion and form information.

  15. Abnormal brain glucose metabolism and depressive mood in patients with pre-dialytic chronic kidney disease: SPM analysis of F-18 FDG positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Sung Min; Song, Sang Heon; Kim, Seong Jang; Kim, Ji Hoon; Kwak, Ihm Soo; Kim, In Ju; Kim, Yong Ki [Pusan National University Hospital, Pusan (Korea, Republic of)

    2007-07-01

    The aim of this study was to investigate the relationship between depressive mood and pre-dialytic CKD, to localize and quantify depressive mood -related lesions in pre-dialytic CKD patients through statistical parametric mapping (SPM) analysis of brain positron emission tomography (PET), and to examine the usefulness of brain PET for early detection and proper treatment of depressive mood. Twenty one patients with stage 5 CKD and 22 healthy volunteers were analyzed by depressive mood assessment and statistical parametric mapping (SPM) analysis of 18F-FDG PET. Depressive mood assessment was done by Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HDRS). The largest clusters were areas including precentral gyrus, prefrontal cortex, and anterior cingulated cortex of left hemisphere. Other clusters were left transverse temporal gyrus, left superior temporal gyrus, right prefrontal cortex, right dorsolateral prefrontal cortex (BA 46, 44), right inferior frontal gyrus, right inferior parietal lobule, left angular gyrus. In addition, correlation was found between hypometabolized areas and HDRS scores of CKD patients in right prefrontal cortex (BA 11) and right anterior cingulated gyrus (BA 24). In conclusion, this study demonstrated specific depressive mood-related abnormal metabolic lesion. Interestingly, in CKD patients with severe depressive mood, cerebral metabolism was similar to that of MDD.

  16. Abnormal brain glucose metabolism and depressive mood in patients with pre-dialytic chronic kidney disease: SPM analysis of F-18 FDG positron emission tomography

    International Nuclear Information System (INIS)

    Jun, Sung Min; Song, Sang Heon; Kim, Seong Jang; Kim, Ji Hoon; Kwak, Ihm Soo; Kim, In Ju; Kim, Yong Ki

    2007-01-01

    The aim of this study was to investigate the relationship between depressive mood and pre-dialytic CKD, to localize and quantify depressive mood -related lesions in pre-dialytic CKD patients through statistical parametric mapping (SPM) analysis of brain positron emission tomography (PET), and to examine the usefulness of brain PET for early detection and proper treatment of depressive mood. Twenty one patients with stage 5 CKD and 22 healthy volunteers were analyzed by depressive mood assessment and statistical parametric mapping (SPM) analysis of 18F-FDG PET. Depressive mood assessment was done by Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HDRS). The largest clusters were areas including precentral gyrus, prefrontal cortex, and anterior cingulated cortex of left hemisphere. Other clusters were left transverse temporal gyrus, left superior temporal gyrus, right prefrontal cortex, right dorsolateral prefrontal cortex (BA 46, 44), right inferior frontal gyrus, right inferior parietal lobule, left angular gyrus. In addition, correlation was found between hypometabolized areas and HDRS scores of CKD patients in right prefrontal cortex (BA 11) and right anterior cingulated gyrus (BA 24). In conclusion, this study demonstrated specific depressive mood-related abnormal metabolic lesion. Interestingly, in CKD patients with severe depressive mood, cerebral metabolism was similar to that of MDD

  17. Abnormal regional spontaneous neuronal activity associated with symptom severity in treatment-naive patients with obsessive-compulsive disorder revealed by resting-state functional MRI.

    Science.gov (United States)

    Qiu, Linlin; Fu, Xiangshuai; Wang, Shuai; Tang, Qunfeng; Chen, Xingui; Cheng, Lin; Zhang, Fuquan; Zhou, Zhenhe; Tian, Lin

    2017-02-15

    A large number of neuroimaging studies have revealed the dysfunction of brain activities in obsessive-compulsive disorder (OCD) during various tasks. However, regional spontaneous activity abnormalities in OCD are gradually being revealed. In this current study, we aimed to investigate cerebral regions with abnormal spontaneous activity using resting-state functional magnetic resonance imaging (fMRI) and further explored the relationship between the spontaneous neuronal activity and symptom severity of patients with OCD. Thirty-one patients with OCD and 32 age-and sex-matched normal controls received the fMRI scans and fractional amplitude of low-frequency fluctuation (fALFF) approach was applied to identify the abnormal brain activity. We found that patients with OCD showed decreased fALFF not only in the cortical-striato-thalamo-cortical (CSTC) circuits like the thalamus, but also in other cerebral systems like the cerebellum, the parietal cortex and the temporal cortex. Additionally, OCD patients demonstrated significant associations between decreased fALFF and obsessive-compulsive symptom severity in the thalamus, the paracentral lobule and the cerebellum. Our results provide evidence for abnormal spontaneous neuronal activity in distributed cerebral areas and support the notion that brain areas outside the CSTC circuits may also play an important role in the pathophysiology of OCD. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. The Neuroanatomical Basis for Posterior Superior Parietal Lobule Control Lateralization of visuospatial Attention

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    Yan eWu

    2016-03-01

    Full Text Available The right hemispheric dominance in visuospatial attention in human brain has been well established. Converging evidence has documented that ventral posterior parietal cortex (PPC plays an important role in visuospatial attention. The role of dorsal PPC subregions, especially the superior parietal lobule (SPL in visuospatial attention is still controversial. In the current study, we used repetitive transcranial magnetic stimulation (rTMS and diffusion magnetic resonance imaging (MRI techniques to test the role of posterior SPL in visuospatial attention and to investigate the potential neuroanatomical basis for right hemisphere dominance in visuospatial function. TMS results unraveled that the right SPL predominantly mediated visuospatial attention compared to left SPL. Anatomical connections analyses between the posterior SPL and the intrahemispheric frontal subregions and the contralateral PPC revealed that right posterior SPL has stronger anatomical connections with the ipsilateral middle frontal gyrus, with the ipsilateral inferior frontal gyrus, and with contralateral PPC than that of the left posterior SPL. Furthermore, these asymmetric anatomical connections were closely related to behavioral performances. Our findings indicate that SPL plays a crucial role in regulating visuospatial attention, and dominance of visuospatial attention results from unbalanced interactions between the bilateral fronto-parietal networks and the interhemispheric parietal network.

  19. Dissociable Changes of Frontal and Parietal Cortices in Inherent Functional Flexibility across the Human Life Span.

    Science.gov (United States)

    Yin, Dazhi; Liu, Wenjing; Zeljic, Kristina; Wang, Zhiwei; Lv, Qian; Fan, Mingxia; Cheng, Wenhong; Wang, Zheng

    2016-09-28

    Extensive evidence suggests that frontoparietal regions can dynamically update their pattern of functional connectivity, supporting cognitive control and adaptive implementation of task demands. However, it is largely unknown whether this flexibly functional reconfiguration is intrinsic and occurs even in the absence of overt tasks. Based on recent advances in dynamics of resting-state functional resonance imaging (fMRI), we propose a probabilistic framework in which dynamic reconfiguration of intrinsic functional connectivity between each brain region and others can be represented as a probability distribution. A complexity measurement (i.e., entropy) was used to quantify functional flexibility, which characterizes heterogeneous connectivity between a particular region and others over time. Following this framework, we identified both functionally flexible and specialized regions over the human life span (112 healthy subjects from 13 to 76 years old). Across brainwide regions, we found regions showing high flexibility mainly in the higher-order association cortex, such as the lateral prefrontal cortex (LPFC), lateral parietal cortex, and lateral temporal lobules. In contrast, visual, auditory, and sensory areas exhibited low flexibility. Furthermore, we observed that flexibility of the right LPFC improved during maturation and reduced due to normal aging, with the opposite occurring for the left lateral parietal cortex. Our findings reveal dissociable changes of frontal and parietal cortices over the life span in terms of inherent functional flexibility. This study not only provides a new framework to quantify the spatiotemporal behavior of spontaneous brain activity, but also sheds light on the organizational principle behind changes in brain function across the human life span. Recent neuroscientific research has demonstrated that the human capability of adaptive task control is primarily the result of the flexible operation of frontal brain networks. However

  20. Regional intercostal bulging of the parietal pleura

    International Nuclear Information System (INIS)

    Jantsch, H.; Greene, R.; Lechner, G.; Mavritz, W.; Pichler, W.; Winkler, M.; Zadrobilek, E.

    1989-01-01

    This paper describes bedside radiographs with localized intercostal bulging as the sole indication of tension pneumothorax in six patients with acute deterioration in gas exchange. Relief of the pneumothorax was followed by a rush of gas from the tension space and a prompt improvement in gas exchange. The authors concluded the regional intercostal bulging of the parietal pleura may be the sole indicator of life-threatening tension pneumothorax in patients on mechanical ventilation

  1. Auditory and visual connectivity gradients in frontoparietal cortex.

    Science.gov (United States)

    Braga, Rodrigo M; Hellyer, Peter J; Wise, Richard J S; Leech, Robert

    2017-01-01

    A frontoparietal network of brain regions is often implicated in both auditory and visual information processing. Although it is possible that the same set of multimodal regions subserves both modalities, there is increasing evidence that there is a differentiation of sensory function within frontoparietal cortex. Magnetic resonance imaging (MRI) in humans was used to investigate whether different frontoparietal regions showed intrinsic biases in connectivity with visual or auditory modalities. Structural connectivity was assessed with diffusion tractography and functional connectivity was tested using functional MRI. A dorsal-ventral gradient of function was observed, where connectivity with visual cortex dominates dorsal frontal and parietal connections, while connectivity with auditory cortex dominates ventral frontal and parietal regions. A gradient was also observed along the posterior-anterior axis, although in opposite directions in prefrontal and parietal cortices. The results suggest that the location of neural activity within frontoparietal cortex may be influenced by these intrinsic biases toward visual and auditory processing. Thus, the location of activity in frontoparietal cortex may be influenced as much by stimulus modality as the cognitive demands of a task. It was concluded that stimulus modality was spatially encoded throughout frontal and parietal cortices, and was speculated that such an arrangement allows for top-down modulation of modality-specific information to occur within higher-order cortex. This could provide a potentially faster and more efficient pathway by which top-down selection between sensory modalities could occur, by constraining modulations to within frontal and parietal regions, rather than long-range connections to sensory cortices. Hum Brain Mapp 38:255-270, 2017. © 2016 Wiley Periodicals, Inc. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  2. Distinct parietal sites mediate the influences of mood, arousal, and their interaction on human recognition memory.

    Science.gov (United States)

    Greene, Ciara M; Flannery, Oliver; Soto, David

    2014-12-01

    The two dimensions of emotion, mood valence and arousal, have independent effects on recognition memory. At present, however, it is not clear how those effects are reflected in the human brain. Previous research in this area has generally dealt with memory for emotionally valenced or arousing stimuli, but the manner in which interacting mood and arousal states modulate responses in memory substrates remains poorly understood. We investigated memory for emotionally neutral items while independently manipulating mood valence and arousal state by means of music exposure. Four emotional conditions were created: positive mood/high arousal, positive mood/low arousal, negative mood/high arousal, and negative mood/low arousal. We observed distinct effects of mood valence and arousal in parietal substrates of recognition memory. Positive mood increased activity in ventral posterior parietal cortex (PPC) and orbitofrontal cortex, whereas arousal condition modulated activity in dorsal PPC and the posterior cingulate. An interaction between valence and arousal was observed in left ventral PPC, notably in a parietal area distinct from the those identified for the main effects, with a stronger effect of mood on recognition memory responses here under conditions of relative high versus low arousal. We interpreted the PPC activations in terms of the attention-to-memory hypothesis: Increased arousal may lead to increased top-down control of memory, and hence dorsal PPC activation, whereas positive mood valence may result in increased activity in ventral PPC regions associated with bottom-up attention to memory. These findings indicate that distinct parietal sites mediate the influences of mood, arousal, and their interplay during recognition memory.

  3. Temporo-Parietal and Fronto-Parietal Lobe Contributions to Theory of Mind and Executive Control: An fMRI Study of Verbal Jokes

    Directory of Open Access Journals (Sweden)

    Yu-Chen eChan

    2015-09-01

    Full Text Available ‘Getting a joke’ always requires resolving an apparent incongruity but the particular cognitive operations called upon vary depending on the nature of the joke itself. Previous research has identified the primary neural correlates of the cognitive and affective processes called upon to respond to humor generally, but little work has been done on the substrates underlying the distinct cognitive operations required to comprehend particular joke types. This study explored the neural correlates of the cognitive processes required to successfully comprehend three joke types: bridging-inference jokes, exaggeration jokes and ambiguity jokes. For all joke types, the left dlPFC appeared to support common cognitive mechanisms, such as script-shifting, while the vACC was associated with affective appreciation. The temporo-parietal lobe (TPJ and MTG was associated with bridging-inference jokes, suggesting involvement of these regions with ‘theory of mind’ processing. The ventral fronto-parietal lobe (IPL and IFG was associated with both exaggeration and ambiguity jokes, suggesting that it supports executive control processes such as retrieval from episodic memory, self-awareness, and language-based decoding. The social-affective appreciation of verbal jokes was associated with activity in the orbitofrontal cortex, amygdala, ventral anterior cingulate cortex (vACC, and parahippocampal gyrus. These results allow a more precise account of the neural

  4. Sustained attention is associated with right superior longitudinal fasciculus and superior parietal white matter microstructure in children

    DEFF Research Database (Denmark)

    Klarborg, Brith; Skak Madsen, Kathrine; Vestergaard, Martin

    2013-01-01

    Sustained attention develops during childhood and has been linked to the right fronto-parietal cortices in functional imaging studies; however, less is known about its relation to white matter (WM) characteristics. Here we investigated whether the microstructure of the WM underlying and connecting...... the right fronto-parietal cortices was associated with sustained attention performance in a group of 76 typically developing children aged 7-13 years. Sustained attention was assessed using a rapid visual information processing paradigm. The two behavioral measures of interest were the sensitivity index d......' and the coefficient of variation in reaction times (RT(CV) ). Diffusion-weighted imaging was performed. Mean fractional anisotropy (FA) was extracted from the WM underlying right dorsolateral prefrontal (DLPFC) and parietal cortex (PC), and the right superior longitudinal fasciculus (SLF), as well as equivalent...

  5. Haptically guided grasping. FMRI shows right-hemisphere parietal stimulus encoding, and bilateral dorso-ventral parietal gradients of object- and action-related processing during grasp execution

    Directory of Open Access Journals (Sweden)

    Mattia eMarangon

    2016-01-01

    Full Text Available The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks. None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

  6. Examining the role of the temporo-parietal network in memory, imagery and viewpoint transformations

    Directory of Open Access Journals (Sweden)

    Kiret eDhindsa

    2014-09-01

    Full Text Available The traditional view of the medial temporal lobe (MTL focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g. O’Keefe (1976; Ekstrom et al. (2003; King et al. (2002. According to our BBB model (Byrne et al. (2007, these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal ’window’. Such imagery is necessarily egocentric and forms part of visuospatial working memory, where it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al. (2012; Zhang et al. (2012 supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object 1 from visuospatial working memory (we assume working memory due to the order of tasks and the consistency viewpoint, but long-term memory is also possible, 2 after a rotation of viewpoint, or 3 after a rotation and translation (judgement of relative direction. We found performance-related activity in both tasks requiring viewpoint rotation in the core medial temporal to medial parietal. These results are consistent with the BBB model and shed further light on the mechanisms underlying spatial memory, mental imagery and viewpoint

  7. Larger right posterior parietal volume in action video game experts: a behavioral and voxel-based morphometry (VBM study.

    Directory of Open Access Journals (Sweden)

    Satoshi Tanaka

    Full Text Available Recent studies suggest that action video game players exhibit superior performance in visuospatial cognitive tasks compared with non-game players. However, the neural basis underlying this visuospatial cognitive performance advantage remains largely unknown. The present human behavioral and imaging study compared gray matter volume in action video game experts and non-experts using structural magnetic resonance imaging and voxel-based morphometry analysis. The results revealed significantly larger gray matter volume in the right posterior parietal cortex in experts compared with non-experts. Furthermore, the larger gray matter volume in the right posterior parietal cortex significantly correlated with individual performance in a visual working memory task in experts. These results suggest that differences in brain structure may be linked to extensive video game play, leading to superior visuospatial cognitive performance in action video game experts.

  8. Increased contextual cue utilization with tDCS over the prefrontal cortex during a recognition task

    Science.gov (United States)

    Pergolizzi, Denise; Chua, Elizabeth F.

    2016-01-01

    The precise role of the prefrontal and posterior parietal cortices in recognition performance remains controversial, with questions about whether these regions contribute to recognition via the availability of mnemonic evidence or via decision biases and retrieval orientation. Here we used an explicit memory cueing paradigm, whereby external cues probabilistically predict upcoming memoranda as old or new, in our case with 75% validity, and these cues affect recognition decision biases in the direction of the cue. The present study applied bilateral transcranial direct current stimulation (tDCS) over prefrontal or posterior parietal cortex, or sham tDCS, to test the causal role of these regions in recognition accuracy or decision biasing. Participants who received tDCS over prefrontal cortex showed increased cue utilization compared to tDCS over posterior parietal cortex and sham tDCS, suggesting that the prefrontal cortex is involved in processes that contribute to decision biases in memory. PMID:27845032

  9. Nuclear Glycogen Inclusions in Canine Parietal Cells.

    Science.gov (United States)

    Silvestri, S; Lepri, E; Dall'Aglio, C; Marchesi, M C; Vitellozzi, G

    2017-05-01

    Nuclear glycogen inclusions occur infrequently in pathologic conditions but also in normal human and animal tissues. Their function or significance is unclear. To the best of the authors' knowledge, no reports of nuclear glycogen inclusions in canine parietal cells exist. After initial observations of nuclear inclusions/pseudoinclusions during routine histopathology, the authors retrospectively examined samples of gastric mucosa from dogs presenting with gastrointestinal signs for the presence of intranuclear inclusions/pseudoinclusions and determined their composition using histologic and electron-microscopic methods. In 24 of 108 cases (22%), the authors observed various numbers of intranuclear inclusions/pseudoinclusions within scattered parietal cells. Nuclei were characterized by marked karyomegaly and chromatin margination around a central optically empty or slightly eosinophilic area. The intranuclear inclusions/pseudoinclusions stained positive with periodic acid-Schiff (PAS) and were diastase sensitive, consistent with glycogen. Several PAS-positive/diastase-sensitive sections were further examined by transmission electron microscopy, also using periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining to identify polysaccharides. Ultrastructurally, the nuclear inclusions were composed of electron-dense particles that were not membrane bound, without evidence of nuclear membrane invaginations or cytoplasmic organelles in the nuclei, and positive staining with PA-TCH-SP, confirming a glycogen composition. No cytoplasmic glycogen deposits were observed, suggesting that the intranuclear glycogen inclusions were probably synthesized in loco. Nuclear glycogen inclusions were not associated with gastritis or colonization by Helicobacter-like organisms ( P > .05). Our findings suggest that nuclear glycogen inclusions in canine parietal cells could be an incidental finding. Nevertheless, since nuclear glycogen is present in several pathologic

  10. Transcriptional landscape of glomerular parietal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Sina A Gharib

    Full Text Available Very little is known about the function of glomerular parietal epithelial cells (PECs. In this study, we performed genome-wide expression analysis on PEC-enriched capsulated vs. PEC-deprived decapsulated rat glomeruli to determine the transcriptional state of PECs under normal conditions. We identified hundreds of differentially expressed genes that mapped to distinct biologic modules including development, tight junction, ion transport, and metabolic processes. Since developmental programs were highly enriched in PECs, we characterized several of their candidate members at the protein level. Collectively, our findings confirm that PECs are multifaceted cells and help define their diverse functional repertoire.

  11. The fMRI study on the front-parietal activation in abacus mental calculation trained children

    International Nuclear Information System (INIS)

    Zhao Kunyuan; Wang Bin; Long Jinfeng; Li Lixin; Shen Xiaojun

    2010-01-01

    Objective: To investigate the difference in front-parietal activation between the trained and untrained children engaged in addition and multiplication with functional magnetic resonance imaging (fMRI), and to explore the role of abacus mental calculation in brain development. Methods: Twenty-four children trained with abacus mental calculation and twelve untrained children performed mental calculation tasks including addition, multiplication and number-object control judging tasks. Blood oxygenation level dependence (BOLD) fMRI was performed when they were calculating. All data were analyzed by SPM2 (statistical parametric mapping 2) to generate the brain activation map. Results: The performance of the trained group had better correctness and shorter reaction time than that of the untrained group. The front-parietal activation between two groups had obvious difference. The activation involved less prefrontal cortex in the trained group than in the untrained group (P<0.05). The parietal activation in the trained group was mainly in the posterior superior parietal lobe/ precuneus, whereas the activation areas focused on the inferior parietal lobule in the untrained group. Conclusion: Abacus mental calculation involves multiple functional areas. and these areas may work together as a whole in processing arithmetic problems. Abacus mental calculation not only enhances the information processing in some brain areas and improves the utilization efficiency of neural resources, but also plays an important role in developing brain. (authors)

  12. Congenital Abnormalities

    Science.gov (United States)

    ... tube defects. However, there is also a genetic influence to this type of congenital anomaly. Unknown Causes The vast majority of congenital abnormalities have no known cause. This is particularly troubling for parents who plan to have more children, because there is no way to predict if ...

  13. Frontoparietal regions may become hypoactive after intermittent theta burst stimulation over the contralateral homologous cortex in humans.

    Science.gov (United States)

    He, Xiaofei; Lan, Yue; Xu, Guangqing; Mao, Yurong; Chen, Zhenghong; Huang, Dongfeng; Pei, Zhong

    2013-12-01

    Brain injury to the dorsal frontoparietal networks, including the posterior parietal cortex (PPC) and dorsolateral prefrontal cortex (DLPFC), commonly cause spatial neglect. However, the interaction of these different regions in spatial attention is unclear. The aim of the present study was to investigate whether hyperexcitable neural networks can cause an abnormal interhemispheric inhibition. The Attention Network Test was used to test subjects following intermittent theta burst stimulation (iTBS) to the left or right frontoparietal networks. During the Attention Network Test task, all subjects tolerated each conditioning iTBS without any obvious iTBS-related side effects. Subjects receiving real-right-PPC iTBS showed significant enhancement in both alerting and orienting efficiency compared with those receiving either sham-right-PPC iTBS or real-left-PPC iTBS. Moreover, subjects exposed to the real-right-DLPFC iTBS exhibited significant improvement in both alerting and executive control efficiency, compared with those exposed to either the sham-right-DLPFC or real-left-DLPFC conditioning. Interestingly, compared with subjects exposed to the sham-left-PPC stimuli, subjects exposed to the real-left-PPC iTBS had a significant deficit in the orienting index. The present study indicates that iTBS over the contralateral homologous cortex may induce the hypoactivity of the right PPC through interhemispheric competition in spatial orienting attention.

  14. Dissociable parietal regions facilitate successful retrieval of recently learned and personally familiar information.

    Science.gov (United States)

    Elman, Jeremy A; Cohn-Sheehy, Brendan I; Shimamura, Arthur P

    2013-03-01

    In fMRI analyses, the posterior parietal cortex (PPC) is particularly active during the successful retrieval of episodic memory. To delineate the neural correlates of episodic retrieval more succinctly, we compared retrieval of recently learned spatial locations (photographs of buildings) with retrieval of previously familiar locations (photographs of familiar campus buildings). Episodic retrieval of recently learned locations activated a circumscribed region within the ventral PPC (anterior angular gyrus and adjacent regions in the supramarginal gyrus) as well as medial PPC regions (posterior cingulated gyrus and posterior precuneus). Retrieval of familiar locations activated more posterior regions in the ventral PPC (posterior angular gyrus, LOC) and more anterior regions in the medial PPC (anterior precuneus and retrosplenial cortex). These dissociable effects define more precisely PPC regions involved in the retrieval of recent, contextually bound information as opposed to regions involved in other processes, such as visual imagery, scene reconstruction, and self-referential processing. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Temporary interference over the posterior parietal cortices disrupts thermoregulatory control in humans.

    Directory of Open Access Journals (Sweden)

    Alberto Gallace

    Full Text Available The suggestion has recently been made that certain higher-order cortical areas involved in supporting multisensory representations of the body, and of the space around it, might also play a role in controlling thermoregulatory functions. Here we demonstrate that temporary interference with the function of one of these areas, the posterior parietal cortex, by repetitive transcranial magnetic stimulation, results in a decrease in limb temperature. By contrast, interference with the activity of a sensory-specific area (the primary somatosensory cortex had no effect on temperature. The results of this experiment suggest that associative multisensory brain areas might exert a top-down modulation over basic physiological control. Such a function might be part of a larger neural circuit responsible for maintaining the integrity of the body at both a homeostatic and a psychological level.

  16. Attention enhances multi-voxel representation of novel objects in frontal, parietal and visual cortices.

    Science.gov (United States)

    Woolgar, Alexandra; Williams, Mark A; Rich, Anina N

    2015-04-01

    Selective attention is fundamental for human activity, but the details of its neural implementation remain elusive. One influential theory, the adaptive coding hypothesis (Duncan, 2001, An adaptive coding model of neural function in prefrontal cortex, Nature Reviews Neuroscience 2:820-829), proposes that single neurons in certain frontal and parietal regions dynamically adjust their responses to selectively encode relevant information. This selective representation may in turn support selective processing in more specialized brain regions such as the visual cortices. Here, we use multi-voxel decoding of functional magnetic resonance images to demonstrate selective representation of attended--and not distractor--objects in frontal, parietal, and visual cortices. In addition, we highlight a critical role for task demands in determining which brain regions exhibit selective coding. Strikingly, representation of attended objects in frontoparietal cortex was highest under conditions of high perceptual demand, when stimuli were hard to perceive and coding in early visual cortex was weak. Coding in early visual cortex varied as a function of attention and perceptual demand, while coding in higher visual areas was sensitive to the allocation of attention but robust to changes in perceptual difficulty. Consistent with high-profile reports, peripherally presented objects could also be decoded from activity at the occipital pole, a region which corresponds to the fovea. Our results emphasize the flexibility of frontoparietal and visual systems. They support the hypothesis that attention enhances the multi-voxel representation of information in the brain, and suggest that the engagement of this attentional mechanism depends critically on current task demands. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Attention as the 'glue' for object integration in parietal extinction.

    Science.gov (United States)

    Conci, Markus; Groß, Julia; Keller, Ingo; Müller, Hermann J; Finke, Kathrin

    2018-04-01

    Patients with unilateral, parietal brain damage frequently show visual extinction, which manifests in a failure to identify contralesional stimuli when presented simultaneously with other, ipsilesional stimuli (but full awareness for single stimulus presentations). Extinction reflects an impairment of spatial selective attention, leaving basic preattentive processing unaffected. For instance, access to bilaterally grouped objects is usually spared in extinction, suggesting that grouping occurs at a stage preceding (in the patients: abnormally biased) spatial-attentional selection. Here, we reinvestigated this notion by comparing (largely between participants, but also within a single-case participant) conditions with objects that varied in their dominant direction of grouping: from the attended to the non-attended hemifield (data from Conci et al., 2009) versus from the non-attended to the attended hemifield (new data). We observe complete absence of extinction when shape completion extended from the attended hemifield. By contrast, extinction was not diminished when object groupings propagate from the unattended hemifield. Moreover, we found the individual severity of the attentional impairment (assessed by a standard "inattention" test) to be directly related to the degree of completion in the unattended hemifield. This pattern indicates that grouping can overcome visual extinction only when object integration departs from the attended visual field, implying, contrary to many previous accounts, that attention is crucial for grouping to be initiated. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Parietal and premotor cortices: activation reflects imitation accuracy during observation, delayed imitation and concurrent imitation.

    Science.gov (United States)

    Krüger, Britta; Bischoff, Matthias; Blecker, Carlo; Langhanns, Christine; Kindermann, Stefan; Sauerbier, Isabell; Reiser, Mathias; Stark, Rudolf; Munzert, Jörn; Pilgramm, Sebastian

    2014-10-15

    This study investigated whether activation within areas belonging to the action observation and imitation network reveals a linear relation to the subsequent accuracy of imitating a bimanual rhythmic movement measured via a motion capturing system. 20 participants were scanned with functional magnetic resonance imaging (fMRI) when asked to imitate observed bimanual movements either concurrently versus with a delay (2s) or simply to observe the movements without imitation. Results showed that action observation relates to activation within classic mirror-related areas. Activation patterns were more widespread when participants were asked to imitate the movement. During observation with concurrent imitation, activation in the left inferior parietal lobe (IPL) was associated negatively with imitation accuracy. During observation in the delayed imitation condition, higher subsequent imitation accuracy was coupled with higher activation in the right superior parietal lobe (SPL) and the left parietal operculum (POp). During the delayed imitation itself, a negative association between imitation accuracy and brain activation was revealed in the right ventral premotor cortex (vPMC). We conclude that the IPL is involved in online comparison and visuospatial attention processes during imitation, the SPL provides a kinesthetic blueprint during movement observation, the POp preserves body identity, and the vPMC recruits motor representations--especially when no concurrent visual guidance is possible. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Fronto-Parietal Network Reconfiguration Supports the Development of Reasoning Ability.

    Science.gov (United States)

    Wendelken, Carter; Ferrer, Emilio; Whitaker, Kirstie J; Bunge, Silvia A

    2016-05-01

    The goal of this fMRI study was to examine how well developmental improvements in reasoning ability can be explained by changes in functional connectivity between specific nodes in prefrontal and parietal cortices. To this end, we examined connectivity within the lateral fronto-parietal network (LFPN) and its relation to reasoning ability in 132 children and adolescents aged 6-18 years, 56 of whom were scanned twice over the course of 1.5 years. Developmental changes in strength of connections within the LFPN were most prominent in late childhood and early adolescence. Reasoning ability was related to functional connectivity between left rostrolateral prefrontal cortex (RLPFC) and inferior parietal lobule (IPL), but only among 12-18-year olds. For 9-11-year olds, reasoning ability was most strongly related to connectivity between left and right RLPFC; this relationship was mediated by working memory. For 6-8-year olds, significant relationships between connectivity and performance were not observed; in this group, processing speed was the primary mediator of improvement in reasoning ability. We conclude that different connections best support reasoning at different points in development and that RLPFC-IPL connectivity becomes an important predictor of reasoning during adolescence. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Frontal and parietal theta burst TMS impairs working memory for visual-spatial conjunctions.

    Science.gov (United States)

    Morgan, Helen M; Jackson, Margaret C; van Koningsbruggen, Martijn G; Shapiro, Kimron L; Linden, David E J

    2013-03-01

    In tasks that selectively probe visual or spatial working memory (WM) frontal and posterior cortical areas show a segregation, with dorsal areas preferentially involved in spatial (e.g. location) WM and ventral areas in visual (e.g. object identity) WM. In a previous fMRI study [1], we showed that right parietal cortex (PC) was more active during WM for orientation, whereas left inferior frontal gyrus (IFG) was more active during colour WM. During WM for colour-orientation conjunctions, activity in these areas was intermediate to the level of activity for the single task preferred and non-preferred information. To examine whether these specialised areas play a critical role in coordinating visual and spatial WM to perform a conjunction task, we used theta burst transcranial magnetic stimulation (TMS) to induce a functional deficit. Compared to sham stimulation, TMS to right PC or left IFG selectively impaired WM for conjunctions but not single features. This is consistent with findings from visual search paradigms, in which frontal and parietal TMS selectively affects search for conjunctions compared to single features, and with combined TMS and functional imaging work suggesting that parietal and frontal regions are functionally coupled in tasks requiring integration of visual and spatial information. Our results thus elucidate mechanisms by which the brain coordinates spatially segregated processing streams and have implications beyond the field of working memory. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Muscarinic responses of gastric parietal cells

    International Nuclear Information System (INIS)

    Wilkes, J.M.; Kajimura, M.; Scott, D.R.; Hersey, S.J.; Sachs, G.

    1991-01-01

    Isolated rabbit gastric glands were used to study the nature of the muscarinic cholinergic responses of parietal cells. Carbachol stimulation of acid secretion, as measured by the accumulation of aminopyrine, was inhibited by the M1 antagonist, pirenzepine, with an IC50 of 13 microM; by the M2 antagonist, 11,2-(diethylamino)methyl-1 piperidinyl acetyl-5,11-dihydro-6H-pyrido 2,3-b 1,4 benzodiazepin-6-one (AF-DX 116), with an IC50 of 110 microM; and by the M1/M3 antagonist, diphenyl-acetoxy-4-methylpiperidinemethiodide, with an IC50 of 35 nM. The three antagonists displayed equivalent IC50 values for the inhibition of carbachol-stimulated production of 14CO2 from radiolabeled glucose, which is a measure of the turnover of the H,K-ATPase, the final step of acid secretion. Intracellular calcium levels were measured in gastric glands loaded with FURA 2. Carbachol was shown to both release calcium from an intracellular pool and to promote calcium entry across the plasma membrane. The calcium entry was inhibitable by 20 microM La3+. The relative potency of the three muscarinic antagonists for inhibition of calcium entry was essentially the same as for inhibition of acid secretion or pump related glucose oxidation. Image analysis of the glands showed the effects of carbachol, and of the antagonists, on intracellular calcium were occurring largely in the parietal cell. The rise in cell calcium due to release of calcium from intracellular stores was inhibited by 4-DAMP with an IC50 of 1.7 nM, suggesting that the release pathway was regulated by a low affinity M3 muscarinic receptor or state; Ca entry and acid secretion are regulated by a high affinity M3 muscarinic receptor or state, inhibited by higher 4-DAMP concentrations, suggesting that it is the steady-state elevation of Ca that is related to parietal cell function rather than the [Ca]i transient

  2. Propofol Compared to Isoflurane Inhibits Mitochondrial Metabolism in Immature Swine Cerebral Cortex

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    Kajimoto, Masaki; Atkinson, D. B.; Ledee, Dolena R.; Kayser, Ernst-Bernhard; Morgan, Phil G.; Sedensky, Margaret M.; Isern, Nancy G.; Des Rosiers, Christine; Portman, Michael A.

    2014-01-08

    Anesthetics used in infants and children are implicated in development of neurocognitive disorders. Although propofol induces neuroapoptosis in developing brain, the underlying mechanisms require elucidation and may have an energetic basis. We studied substrate utilization in an immature swine model anesthetized with either propofol or isoflurane for 4 hours. Piglets were infused with 13-Carbon labeled glucose and leucine in the common carotid artery in order to assess citric acid cycle (CAC) metabolism in the parietal cortex. The anesthetics produced similar systemic hemodynamics and cerebral oxygen saturation by near-infrared-spectroscopy. Compared to isoflurane, propofol depleted ATP and glycogen stores. Propofol also decreased pools of the CAC intermediates, citrate and α-ketoglutarate, while markedly increasing succinate along with decreasing mitochondrial complex II activity. Propofol also inhibited acetyl-CoA entry into the CAC through pyruvate dehydrogenase, while promoting glycolytic flux with marked accumulation of lactate. Although oxygen supply appeared similar between the anesthetic groups, propofol yielded a metabolic phenotype which resembled a hypoxic state. Propofol impairs substrate flux through the CAC in the immature cerebral cortex. These impairments occurred without systemic metabolic perturbations which typically accompany propofol infusion syndrome. These metabolic abnormalities may play a role in neurotoxity observed with propofol in the vulnerable immature brain.

  3. Frontal and parietal transcranial magnetic stimulation (TMS) disturbs programming of saccadic eye movements.

    Science.gov (United States)

    Zangemeister, W H; Canavan, A G; Hoemberg, V

    1995-11-01

    Transcranial magnetic stimulation (TMS) of human motor cortex typically evoked motor responses. TMS has failed to elicit eye movements in humans, whereas prolongations of saccadic latency have been reported with TMS. In previous studied we demonstrated that saccades can be abolished or saccadic trajectories can be changed through TMS in the 100 msec before saccade onset. This effect was especially marked when TMS was applied parietally. TMS never influenced a saccade in flight. Simulations of predictive experimental saccades that were impaired through TMS of the frontal or parietal cortex demonstrated especially that the dynamics of small saccades were markedly influenced, resulting in a significant decrease in acceleration and amplitude, or an almost complete inhibition. The impact of inhibition through TMS was critically dependent on timing: early TMS (-70 msec) had a much larger inhibitory effect than late TMS (-20 msec) on experimental saccades. Differential timing of TMS in influencing the cortical control signal is demonstrated through simulations of a reciprocally innervated eye movement model that paralleled empirically determined changes in eye movement dynamics after real TMS. There is a reasonable match between the model and the experimental data. We conclude that the inhibitory action of a presaccadic disturbance, such as a TMS pulse, on saccadic programming is inversely related to timing and amplitude of the predicted saccade.

  4. Perceptual difficulty in source memory encoding and retrieval: prefrontal versus parietal electrical brain activity.

    Science.gov (United States)

    Kuo, Trudy Y; Van Petten, Cyma

    2008-01-01

    It is well established that source memory retrieval--remembering relationships between a core item and some additional attribute of an event--engages prefrontal cortex (PFC) more than simple item memory. In event-related potentials (ERPs), this is manifest in a late-onset difference over PFC between studied items which mandate retrieval of a second attribute, and unstudied items which can be immediately rejected. Although some sorts of attribute conjunctions are easier to remember than others, the role of source retrieval difficulty on prefrontal activity has received little attention. We examined memory for conjunctions of object shape and color when color was an integral part of the depicted object, and when monochrome objects were surrounded by colored frames. Source accuracy was reliably worse when shape and color were spatially separated, but prefrontal activity did not vary across the object-color and frame-color conditions. The insensitivity of prefrontal ERPs to this perceptual manipulation of difficulty stands in contrast to their sensitivity to encoding task: deliberate voluntary effort to integrate objects and colors during encoding reduced prefrontal activity during retrieval, but perceptual organization of stimuli did not. The amplitudes of ERPs over parietal cortex were larger for frame-color than object-color stimuli during both study and test phases of the memory task. Individual variability in parietal ERPs was strongly correlated with memory accuracy, which we suggest reflects a contribution of visual working memory to long-term memory. We discuss multiple bottlenecks for source memory performance.

  5. Ictal Cardiac Ryhthym Abnormalities.

    Science.gov (United States)

    Ali, Rushna

    2016-01-01

    Cardiac rhythm abnormalities in the context of epilepsy are a well-known phenomenon. However, they are under-recognized and often missed. The pathophysiology of these events is unclear. Bradycardia and asystole are preceded by seizure onset suggesting ictal propagation into the cortex impacting cardiac autonomic function, and the insula and amygdala being possible culprits. Sudden unexpected death in epilepsy (SUDEP) refers to the unanticipated death of a patient with epilepsy not related to status epilepticus, trauma, drowning, or suicide. Frequent refractory generalized tonic-clonic seizures, anti-epileptic polytherapy, and prolonged duration of epilepsy are some of the commonly identified risk factors for SUDEP. However, the most consistent risk factor out of these is an increased frequency of generalized tonic-clonic seizures (GTC). Prevention of SUDEP is extremely important in patients with chronic, generalized epilepsy. Since increased frequency of GTCS is the most consistently reported risk factor for SUDEP, effective seizure control is the most important preventive strategy.

  6. The Effects of Maternal Hyperthyroidism on Histologic Changes in Parietal Lobe in Rat Embryos

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    Fatemeh Mirsafi

    2017-05-01

    Full Text Available Background Maternal hyperthyroidism causes developmental defects on the nervous system of fetuses. Objectives The present study was designed to study the effects of maternal hyperthyroidism on the development of the parietal lobe in the brain of rat embryos. Methods In this experimental study, thirty Sprague-Dawley rats were randomly divided into three groups. The control group received no injections, the sham group received intraperitoneal injections of distilled water solution containing salt and polysorbate (solvent of levothyroxine, and the experimental group received once-daily, intraperitoneal injections of 0.5 mg/kg levothyroxine for a 10-day period to become hyperthyroid rats. The hyperthyroid rats were then mated, and all pregnant rats were killed on the 20th day of gestation. Fetuses were removed, fixed, and processed for histological procedures. The fetuses were sagitally sectioned at 5 µ thickness and stained with hematoxylin-eosin (H and E technique. The sections were examined using a light microscope and Motic software. Results The results showed no significant difference in the studied variables between the sham and control groups. A significantly increase in body weight and a significant decrease in crown-rump length of embryos was observed in the experimental group when compared to the control group. The mean total thickness of the parietal cortex, ventricular layer, and intermediate layer of embryos showed a significant decrease in the experimental group compared to the control and sham groups. The mean number of cells also showed a significant decrease in the intermediate and ventricular layers in the experimental group compared to the control and sham groups. Conclusions This study showed that maternal hyperthyroidism leads to a reduction in development of the parietal cortex in embryos. Maternal hyperthyroidism can disturb the growth and development of embryos.

  7. Fronto-parietal coding of goal-directed actions performed by artificial agents.

    Science.gov (United States)

    Kupferberg, Aleksandra; Iacoboni, Marco; Flanagin, Virginia; Huber, Markus; Kasparbauer, Anna; Baumgartner, Thomas; Hasler, Gregor; Schmidt, Florian; Borst, Christoph; Glasauer, Stefan

    2018-03-01

    With advances in technology, artificial agents such as humanoid robots will soon become a part of our daily lives. For safe and intuitive collaboration, it is important to understand the goals behind their motor actions. In humans, this process is mediated by changes in activity in fronto-parietal brain areas. The extent to which these areas are activated when observing artificial agents indicates the naturalness and easiness of interaction. Previous studies indicated that fronto-parietal activity does not depend on whether the agent is human or artificial. However, it is unknown whether this activity is modulated by observing grasping (self-related action) and pointing actions (other-related action) performed by an artificial agent depending on the action goal. Therefore, we designed an experiment in which subjects observed human and artificial agents perform pointing and grasping actions aimed at two different object categories suggesting different goals. We found a signal increase in the bilateral inferior parietal lobule and the premotor cortex when tool versus food items were pointed to or grasped by both agents, probably reflecting the association of hand actions with the functional use of tools. Our results show that goal attribution engages the fronto-parietal network not only for observing a human but also a robotic agent for both self-related and social actions. The debriefing after the experiment has shown that actions of human-like artificial agents can be perceived as being goal-directed. Therefore, humans will be able to interact with service robots intuitively in various domains such as education, healthcare, public service, and entertainment. © 2017 Wiley Periodicals, Inc.

  8. Parietal lesions produce illusory conjunction errors in rats

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    Raymond PIERRE Kesner

    2012-05-01

    Full Text Available When several different objects are presented, visual objects are perceived correctly only if their features are identified and then bound together. Illusory-conjunction errors result when an object is correctly identified but is combined incorrectly. The parietal cortex (PPC has been shown repeatedly to play an important role in feature binding. The present study builds on a series of recent studies that have made use of visual search paradigms to elucidate the neural system involved in feature binding. This experiment attempts to define the role the PPC plays in binding the properties of a visual object that varies on the features of color and size in rats. Rats with PPC lesions or control surgery were exposed to three blocks of 20 trials administered over a 1-week period, with each block containing ten-one feature and ten-two feature trials. The target object consisted of one color object (e.g. black and white and one size object (e.g. short and tall. Of the ten one feature trials, five of the trials were tailored specifically for size discrimination and five for color discrimination. In the two-feature condition, the animal was required to locate the targeted object among four objects with two objects differing in size and two objects differing in color. The results showed a significant decrease in learning the task for the PPC lesioned rats compared to controls, especially for the two-feature condition. Based on a subsequent error analysis for color and size, the results showed a significant increase in illusory conjunction errors for the PPC lesioned rats relative to controls for color and relative to color discrimination, suggesting that the PPC may support feature binding as it relates to color. There was an increase in illusory conjunctions errors for both the PPC lesioned and control animals for size, but this appeared to be due to a difficulty with size discrimination.

  9. Multimodal FMRI resting-state functional connectivity in granulin mutations: the case of fronto-parietal dementia.

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    Enrico Premi

    Full Text Available BACKGROUND: Monogenic dementias represent a great opportunity to trace disease progression from preclinical to symptomatic stages. Frontotemporal Dementia related to Granulin (GRN mutations presents a specific framework of brain damage, involving fronto-temporal regions and long inter-hemispheric white matter bundles. Multimodal resting-state functional MRI (rs-fMRI is a promising tool to carefully describe disease signature from the earliest disease phase. OBJECTIVE: To define local connectivity alterations in GRN related pathology moving from the presymptomatic (asymptomatic GRN mutation carriers to the clinical phase of the disease (GRN- related Frontotemporal Dementia. METHODS: Thirty-one GRN Thr272fs mutation carriers (14 patients with Frontotemporal Dementia and 17 asymptomatic carriers and 38 healthy controls were recruited. Local connectivity measures (Regional Homogeneity (ReHo, Fractional Amplitude of Low Frequency Fluctuation (fALFF and Degree Centrality (DC were computed, considering age and gender as nuisance variables as well as the influence of voxel-level gray matter atrophy. RESULTS: Asymptomatic GRN carriers had selective reduced ReHo in the left parietal region and increased ReHo in frontal regions compared to healthy controls. Considering Frontotemporal Dementia patients, all measures (ReHo, fALFF and DC were reduced in inferior parietal, frontal lobes and posterior cingulate cortex. Considering GRN mutation carriers, an inverse correlation with age in the posterior cingulate cortex, inferior parietal lobule and orbitofrontal cortex was found. CONCLUSIONS: GRN pathology is characterized by functional brain network alterations even decades before the clinical onset; they involve the parietal region primarily and then spread to the anterior regions of the brain, supporting the concept of molecular nexopathies.

  10. Right hemisphere dominance during spatial selective attention and target detection occurs outside the dorsal fronto-parietal network

    Science.gov (United States)

    Shulman, Gordon L.; Pope, Daniel L. W.; Astafiev, Serguei V.; McAvoy, Mark P.; Snyder, Abraham Z.; Corbetta, Maurizio

    2010-01-01

    Spatial selective attention is widely considered to be right hemisphere dominant. Previous functional magnetic resonance imaging (fMRI) studies, however, have reported bilateral blood-oxygenation-level-dependent (BOLD) responses in dorsal fronto-parietal regions during anticipatory shifts of attention to a location (Kastner et al., 1999; Corbetta et al., 2000; Hopfinger et al., 2000). Right-lateralized activity has mainly been reported in ventral fronto-parietal regions for shifts of attention to an unattended target stimulus (Arrington et al., 2000; Corbetta et al., 2000). However, clear conclusions cannot be drawn from these studies because hemispheric asymmetries were not assessed using direct voxel-wise comparisons of activity in left and right hemispheres. Here, we used this technique to measure hemispheric asymmetries during shifts of spatial attention evoked by a peripheral cue stimulus and during target detection at the cued location. Stimulus-driven shifts of spatial attention in both visual fields evoked right-hemisphere dominant activity in temporo-parietal junction (TPJ). Target detection at the attended location produced a more widespread right hemisphere dominance in frontal, parietal, and temporal cortex, including the TPJ region asymmetrically activated during shifts of spatial attention. However, hemispheric asymmetries were not observed during either shifts of attention or target detection in the dorsal fronto-parietal regions (anterior precuneus, medial intraparietal sulcus, frontal eye fields) that showed the most robust activations for shifts of attention. Therefore, right hemisphere dominance during stimulus-driven shifts of spatial attention and target detection reflects asymmetries in cortical regions that are largely distinct from the dorsal fronto-parietal network involved in the control of selective attention. PMID:20219998

  11. Maps of space in human frontoparietal cortex.

    Science.gov (United States)

    Jerde, Trenton A; Curtis, Clayton E

    2013-12-01

    Prefrontal cortex (PFC) and posterior parietal cortex (PPC) are neural substrates for spatial cognition. We here review studies in which we tested the hypothesis that human frontoparietal cortex may function as a priority map. According to priority map theory, objects or locations in the visual world are represented by neural activity that is proportional to their attentional priority. Using functional magnetic resonance imaging (fMRI), we first identified topographic maps in PFC and PPC as candidate priority maps of space. We then measured fMRI activity in candidate priority maps during the delay periods of a covert attention task, a spatial working memory task, and a motor planning task to test whether the activity depended on the particular spatial cognition. Our hypothesis was that some, but not all, candidate priority maps in PFC and PPC would be agnostic with regard to what was being prioritized, in that their activity would reflect the location in space across tasks rather than a particular kind of spatial cognition (e.g., covert attention). To test whether patterns of delay period activity were interchangeable during the spatial cognitive tasks, we used multivariate classifiers. We found that decoders trained to predict the locations on one task (e.g., working memory) cross-predicted the locations on the other tasks (e.g., covert attention and motor planning) in superior precentral sulcus (sPCS) and in a region of intraparietal sulcus (IPS2), suggesting that these patterns of maintenance activity may be interchangeable across the tasks. Such properties make sPCS in frontal cortex and IPS2 in parietal cortex viable priority map candidates, and suggest that these areas may be the human homologs of the monkey frontal eye field (FEF) and lateral intraparietal area (LIP). Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Bilateral, posterior parietal polymicrogyria as part of speech therapy ...

    African Journals Online (AJOL)

    SA Journal of Radiology ... Magnetic resonance imaging (MRI) has been associated with either diffuse polymicrogyria around the entire extent of the sylvian fissure or in the posterior aspects of the parietal regions, in which case it is called posterior parietal ... This article discusses the possible embryological origin of these

  13. Use of explicit memory cues following parietal lobe lesions.

    Science.gov (United States)

    Dobbins, Ian G; Jaeger, Antonio; Studer, Bettina; Simons, Jon S

    2012-11-01

    The putative role of the lateral parietal lobe in episodic memory has recently become a topic of considerable debate, owing primarily to its consistent activation for studied materials during functional magnetic resonance imaging studies of recognition. Here we examined the performance of patients with parietal lobe lesions using an explicit memory cueing task in which probabilistic cues ("Likely Old" or "Likely New"; 75% validity) preceded the majority of verbal recognition memory probes. Without cues, patients and control participants did not differ in accuracy. However, group differences emerged during the "Likely New" cue condition with controls responding more accurately than parietal patients when these cues were valid (preceding new materials) and trending towards less accuracy when these cues were invalid (preceding old materials). Both effects suggest insufficient integration of external cues into memory judgments on the part of the parietal patients whose cued performance largely resembled performance in the complete absence of cues. Comparison of the parietal patients to a patient group with frontal lobe lesions suggested the pattern was specific to parietal and adjacent area lesions. Overall, the data indicate that parietal lobe patients fail to appropriately incorporate external cues of novelty into recognition attributions. This finding supports a role for the lateral parietal lobe in the adaptive biasing of memory judgments through the integration of external cues and internal memory evidence. We outline the importance of such adaptive biasing through consideration of basic signal detection predictions regarding maximum possible accuracy with and without informative environmental cues. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. White matter abnormalities in young males with antisocial personality disorder Evidence from voxel-based morphometry-diffeomorphic anatomical registration using exponentiated lie algebra analysis

    Institute of Scientific and Technical Information of China (English)

    Daxing Wu; Ying Zhao; Jian Liao; Huifang Yin; Wei Wang

    2011-01-01

    Voxel-based morphometry-diffeomorphic anatomical registration using exponentiated lie algebra analysis was used to investigate the structural characteristics of white matter in young males with antisocial personality disorder (APD) and healthy controls without APD. The results revealed that APD subjects, relative to healthy subjects, exhibited increased white matter volume in the bilateral prefrontal lobe, right insula, precentral gyrus, bilateral superior temporal gyrus, right postcentral gyrus, right inferior parietal lobule, right precuneus, right middle occipital lobe, right parahippocampal gyrus and bilateral cingulate, and decreased volume in the middle temporal cortex and right cerebellum. The white matter volume in the medial frontal gyrus was significantly correlated with antisocial type scores on the Personality Diagnostic Questionnaire in APD subjects. These experimental findings indicate that white matter abnormalities in several brain areas may contribute to antisocial behaviors in APD subjects.

  15. Caracterización del injerto parietal

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    José Manuel Díaz Fernández

    1996-12-01

    Full Text Available Se realizó un estudio descriptivo, longitudinal y prospectivo de 22 pacientes en los que se utilizó el injerto parietal autógeno para reconstruir defectos del cráneo, en los servicios de Cirugía Maxilofacial y Neurocirugía del Hospital Clinicoquirúrgico Docente "Saturnino Lora", de Santiago de Cuba, desde 1988 hasta 1991. El método de extracción del injerto con división in situ resultó el más empleado y el que ofreció las mejores posibilidades de reconstrucción en cuanto a forma, volumen y flexibilidad, por lo que se recomienda en los defectos pequeños y medianos, sobre todo de la región frontal y áreas adyacentes, donde el contorno y la simetría son los 2 aspectos fundamentales que se deben conseguir. El método de división, in vitro se utilizó en las reconstrucciones de las deformidades de grandes dimensiones, particularmente en aquellas que no incluían la frente. El índice de complicaciones fue bajoIt was carried out a descriptive, longitudinal and prospective study of 22 patients in whom an autogenous parietal graft was used to reconstruct cranial defects at the Maxillofacial Surgery and Neurosurgery Department of the "Saturnino Lora" Clinical and Surgical Teaching Hospital, in Santiago de Cuba, from 1988 to 1991. The graft extraction method with division in situ was the most used and offered the best possibilities for reconstruction as regards form, volume and flexibility. Therefore, it is recommended for small and medium defects, particularly of the frontal region and adjacent areas, where contour and symmetry are the two fundamental aspects to be taken into consideration. The method of division in vitro was used to reconstruct large deformities, specially those in which the forehead was not included. The complications index was low

  16. Resting-state functional connectivity of ventral parietal regions associated with attention reorienting and episodic recollection

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    Sander M Daselaar

    2013-02-01

    Full Text Available In functional neuroimaging studies, ventral parietal cortex (VPC is recruited by very different cognitive tasks. Explaining the contributions VPC to these tasks has become a topic of intense study and lively debate. Perception studies frequently find VPC activations during tasks involving attention-reorienting, and memory studies frequently find them during tasks involving episodic recollection. According to the Attention to Memory (AtoM model, both phenomena can be explained by the same VPC function: bottom-up attention. Yet, a recent functional MRI (fMRI meta-analysis suggested that attention-reorienting activations are more frequent in anterior VPC, whereas recollection activations are more frequent in posterior VPC. Also, there is evidence that anterior and posterior VPC regions have different functional connectivity patterns. To investigate these issues, we conducted a resting-state functional connectivity analysis using as seeds the center-of-mass of attention-reorienting and recollection activations in the meta-analysis, which were located in the supramarginal gyrus (SMG, around the temporo-parietal junction—TPJ and in the angular gyrus (AG, respectively. The SMG seed showed stronger connectivity with ventrolateral prefrontal cortex (VLPFC and occipito-temporal cortex, whereas the AG seed showed stronger connectivity with the hippocampus and default network regions. To investigate whether these connectivity differences were graded or sharp, VLPFC and hippocampal connectivity was measured in VPC regions traversing through the SMG and AG seeds. The results showed a graded pattern: VLPFC connectivity gradually decreases from SMG to AG, whereas hippocampal connectivity gradually increases from SMG to AG. Importantly, both gradients showed an abrupt break when extended beyond VPC borders. This finding suggests that functional differences between SMG and AG are more subtle than previously thought. These connectivity differences can be

  17. Dysregulated left inferior parietal activity in schizophrenia and depression: functional connectivity and characterization

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    Veronika I. Müller

    2013-06-01

    Full Text Available The inferior parietal cortex (IPC is a heterogeneous region that is known to be involved in a multitude of diverse different tasks and processes, though its contribution to these often-complex functions is yet poorly understood. In a previous study we demonstrated that patients with depression failed to deactivate the left IPC during processing of congruent audiovisual information. We now found the same dysregulation (same region and condition in schizophrenia. By using task-independent (resting state and task-dependent (MACM analyses we aimed at characterizing this particular region with regard to its connectivity and function. Across both approaches, results revealed functional connectivity of the left inferior parietal seed region with bilateral IPC, precuneus and posterior cingulate cortex (PrC/PCC, medial orbitofrontal cortex (mOFC, left middle frontal (MFG as well as inferior frontal (IFG gyrus. Network-level functional characterization further revealed that on the one hand, all interconnected regions are part of a network involved in memory processes. On the other hand, sub-networks are formed when emotion, language, social cognition and reasoning processes are required. Thus, the IPC-region that is dysregulated in both depression and schizophrenia is functionally connected to a network of regions which, depending on task demands may form sub-networks. These results therefore indicate that dysregulation of left IPC in depression and schizophrenia might not only be connected to deficits in audiovisual integration, but is possibly also associated to impaired memory and deficits in emotion processing in these patient groups.

  18. The parietal memory network activates similarly for true and associative false recognition elicited via the DRM procedure.

    Science.gov (United States)

    McDermott, Kathleen B; Gilmore, Adrian W; Nelson, Steven M; Watson, Jason M; Ojemann, Jeffrey G

    2017-02-01

    Neuroimaging investigations of human memory encoding and retrieval have revealed that multiple regions of parietal cortex contribute to memory. Recently, a sparse network of regions within parietal cortex has been identified using resting state functional connectivity (MRI techniques). The regions within this network exhibit consistent task-related responses during memory formation and retrieval, leading to its being called the parietal memory network (PMN). Among its signature patterns are: deactivation during initial experience with an item (e.g., encoding); activation during subsequent repetitions (e.g., at retrieval); greater activation for successfully retrieved familiar words than novel words (e.g., hits relative to correctly-rejected lures). The question of interest here is whether novel words that are subjectively experienced as having been recently studied would elicit PMN activation similar to that of hits. That is, we compared old items correctly recognized to two types of novel items on a recognition test: those correctly identified as new and those incorrectly labeled as old due to their strong associative relation to the studied words (in the DRM false memory protocol). Subjective oldness plays a strong role in driving activation, as hits and false alarms activated similarly (and greater than correctly-rejected lures). Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Brain Abnormalities in Congenital Fibrosis of the Extraocular Muscles Type 1: A Multimodal MRI Imaging Study.

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    Wen Miao

    Full Text Available To explore the possible brain structural and functional alterations in congenital fibrosis of extraocular muscles type 1 (CFEOM1 patients using multimodal MRI imaging.T1-weighted, diffusion tensor images and functional MRI data were obtained from 9 KIF21A positive patients and 19 age- and gender-matched healthy controls. Voxel based morphometry and tract based spatial statistics were applied to the T1-weighted and diffusion tensor images, respectively. Amplitude of low frequency fluctuations and regional homogeneity were used to process the functional MRI data. We then compared these multimodal characteristics between CFEOM1 patients and healthy controls.Compared with healthy controls, CFEOM1 patients demonstrated increased grey matter volume in bilateral frontal orbital cortex and in the right temporal pole. No diffusion indices changes were detected, indicating unaffected white matter microstructure. In addition, from resting state functional MRI data, trend of amplitude of low-frequency fluctuations increases were noted in the right inferior parietal lobe and in the right frontal cortex, and a trend of ReHo increase (p<0.001 uncorrected in the left precentral gyrus, left orbital frontal cortex, temporal pole and cingulate gyrus.CFEOM1 patients had structural and functional changes in grey matter, but the white matter was unaffected. These alterations in the brain may be due to the abnormality of extraocular muscles and their innervating nerves. Future studies should consider the possible correlations between brain morphological/functional findings and clinical data, especially pertaining to eye movements, to obtain more precise answers about the role of brain area changes and their functional consequence in CFEOM1.

  20. Brain Abnormalities in Congenital Fibrosis of the Extraocular Muscles Type 1: A Multimodal MRI Imaging Study.

    Science.gov (United States)

    Miao, Wen; Man, Fengyuan; Wu, Shaoqin; Lv, Bin; Wang, Zhenchang; Xian, Junfang; Sabel, Bernhard A; He, Huiguang; Jiao, Yonghong

    2015-01-01

    To explore the possible brain structural and functional alterations in congenital fibrosis of extraocular muscles type 1 (CFEOM1) patients using multimodal MRI imaging. T1-weighted, diffusion tensor images and functional MRI data were obtained from 9 KIF21A positive patients and 19 age- and gender-matched healthy controls. Voxel based morphometry and tract based spatial statistics were applied to the T1-weighted and diffusion tensor images, respectively. Amplitude of low frequency fluctuations and regional homogeneity were used to process the functional MRI data. We then compared these multimodal characteristics between CFEOM1 patients and healthy controls. Compared with healthy controls, CFEOM1 patients demonstrated increased grey matter volume in bilateral frontal orbital cortex and in the right temporal pole. No diffusion indices changes were detected, indicating unaffected white matter microstructure. In addition, from resting state functional MRI data, trend of amplitude of low-frequency fluctuations increases were noted in the right inferior parietal lobe and in the right frontal cortex, and a trend of ReHo increase (pleft precentral gyrus, left orbital frontal cortex, temporal pole and cingulate gyrus. CFEOM1 patients had structural and functional changes in grey matter, but the white matter was unaffected. These alterations in the brain may be due to the abnormality of extraocular muscles and their innervating nerves. Future studies should consider the possible correlations between brain morphological/functional findings and clinical data, especially pertaining to eye movements, to obtain more precise answers about the role of brain area changes and their functional consequence in CFEOM1.

  1. Brain Abnormalities in Congenital Fibrosis of the Extraocular Muscles Type 1: A Multimodal MRI Imaging Study

    Science.gov (United States)

    Wu, Shaoqin; Lv, Bin; Wang, Zhenchang; Xian, Junfang; Sabel, Bernhard A.; He, Huiguang; Jiao, Yonghong

    2015-01-01

    Purpose To explore the possible brain structural and functional alterations in congenital fibrosis of extraocular muscles type 1 (CFEOM1) patients using multimodal MRI imaging. Methods T1-weighted, diffusion tensor images and functional MRI data were obtained from 9 KIF21A positive patients and 19 age- and gender- matched healthy controls. Voxel based morphometry and tract based spatial statistics were applied to the T1-weighted and diffusion tensor images, respectively. Amplitude of low frequency fluctuations and regional homogeneity were used to process the functional MRI data. We then compared these multimodal characteristics between CFEOM1 patients and healthy controls. Results Compared with healthy controls, CFEOM1 patients demonstrated increased grey matter volume in bilateral frontal orbital cortex and in the right temporal pole. No diffusion indices changes were detected, indicating unaffected white matter microstructure. In addition, from resting state functional MRI data, trend of amplitude of low-frequency fluctuations increases were noted in the right inferior parietal lobe and in the right frontal cortex, and a trend of ReHo increase (pleft precentral gyrus, left orbital frontal cortex, temporal pole and cingulate gyrus. Conclusions CFEOM1 patients had structural and functional changes in grey matter, but the white matter was unaffected. These alterations in the brain may be due to the abnormality of extraocular muscles and their innervating nerves. Future studies should consider the possible correlations between brain morphological/functional findings and clinical data, especially pertaining to eye movements, to obtain more precise answers about the role of brain area changes and their functional consequence in CFEOM1. PMID:26186732

  2. Inactivation of Parietal Reach Region Affects Reaching But Not Saccade Choices in Internally Guided Decisions.

    Science.gov (United States)

    Christopoulos, Vassilios N; Bonaiuto, James; Kagan, Igor; Andersen, Richard A

    2015-08-19

    The posterior parietal cortex (PPC) has traditionally been considered important for awareness, spatial perception, and attention. However, recent findings provide evidence that the PPC also encodes information important for making decisions. These findings have initiated a running argument of whether the PPC is critically involved in decision making. To examine this issue, we reversibly inactivated the parietal reach region (PRR), the area of the PPC that is specialized for reaching movements, while two monkeys performed a memory-guided reaching or saccade task. The task included choices between two equally rewarded targets presented simultaneously in opposite visual fields. Free-choice trials were interleaved with instructed trials, in which a single cue presented in the peripheral visual field defined the reach and saccade target unequivocally. We found that PRR inactivation led to a strong reduction of contralesional choices, but only for reaches. On the other hand, saccade choices were not affected by PRR inactivation. Importantly, reaching and saccade movements to single instructed targets remained largely intact. These results cannot be explained as an effector-nonspecific deficit in spatial attention or awareness, since the temporary "lesion" had an impact only on reach choices. Hence, the PPR is a part of a network for reach decisions and not just reach planning. There has been an ongoing debate on whether the posterior parietal cortex (PPC) represents only spatial awareness, perception, and attention or whether it is also involved in decision making for actions. In this study we explore whether the parietal reach region (PRR), the region of the PPC that is specialized for reaches, is involved in the decision process. We inactivated the PRR while two monkeys performed reach and saccade choices between two targets presented simultaneously in both hemifields. We found that inactivation affected only the reach choices, while leaving saccade choices intact

  3. Reduced N-acetylaspartate levels in the frontal cortex of 3,4-methylenedioxymethamphetamine (Ecstasy) users: preliminary results.

    Science.gov (United States)

    Reneman, Liesbeth; Majoie, Charles B L M; Flick, Herman; den Heeten, Gerard J

    2002-02-01

    The perceived safety of the recreational drug methylenedioxymethamphetamine (MDMA), or Ecstasy, conflicts with animal evidence indicating that MDMA damages cortical serotonin (5-HT) neurons at doses similar to those used by humans. Few data are available about the effects of MDMA on the human brain. This study was designed to evaluate MDMA-related alterations in metabolite ratios with single-voxel proton ((1)H) MR spectroscopy. Fifteen male MDMA users (mean lifetime exposure, 723 tablets; mean time since last tablet, 12.0 weeks) and 12 age-matched control subjects underwent single-voxel (1)H MR spectroscopy. N-Acetylaspartate (NAA)/creatine (Cr), NAA/Choline (Cho), and myoinositol (MI)/Cr ratios were measured in midfrontal gray matter, midoccipital gray matter, and right parietal white matter. Data were analyzed with linear model-based multivariate analysis of variance. NAA/Cr (P =.04) and NAA/Cho (P =.03) ratios, markers associated with neuronal loss or dysfunction, were reduced in the frontal cortex of MDMA users. Neither NAA/Cr (P =.72) nor NAA/Cho (P =.12) ratios were different between both groups in occipital gray matter and parietal white matter (P =.18). Extent of previous MDMA use and frontal cortical NAA/Cr (rho = -.50, P =.012) or NAA/Cho (rho = -.550, P spectroscopy provide evidence for neuronal abnormality in the frontal cortex of MDMA users; these are correlated with the degree of MDMA exposure. These data suggest that MDMA may be a neurotoxin in humans, as it is in animals.

  4. Examining the role of the temporo-parietal network in memory, imagery, and viewpoint transformations.

    Science.gov (United States)

    Dhindsa, Kiret; Drobinin, Vladislav; King, John; Hall, Geoffrey B; Burgess, Neil; Becker, Suzanna

    2014-01-01

    The traditional view of the medial temporal lobe (MTL) focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g., O'Keefe, 1976; King et al., 2002; Ekstrom et al., 2003). According to our BBB model (Byrne et al., 2007), these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal "window." Such imagery is necessarily egocentric and forms part of visuospatial working memory, in which it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al., 2012; Zhang et al., 2012) supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object (1) from visuospatial working memory (we assume transient working memory due to the order of tasks and the absence of change in viewpoint, but long-term memory retrieval is also possible), (2) after a rotation of viewpoint, or (3) after a rotation and translation of viewpoint (judgment of relative direction). We found performance-related activity in both tasks requiring viewpoint rotation (ROT and JRD, i.e., conditions 2 and 3) in the core medial temporal to medial parietal circuit identified by the BBB model. These results are consistent with the

  5. Monkey cortex through fMRI glasses.

    Science.gov (United States)

    Vanduffel, Wim; Zhu, Qi; Orban, Guy A

    2014-08-06

    In 1998 several groups reported the feasibility of fMRI experiments in monkeys, with the goal to bridge the gap between invasive nonhuman primate studies and human functional imaging. These studies yielded critical insights in the neuronal underpinnings of the BOLD signal. Furthermore, the technology has been successful in guiding electrophysiological recordings and identifying focal perturbation targets. Finally, invaluable information was obtained concerning human brain evolution. We here provide a comprehensive overview of awake monkey fMRI studies mainly confined to the visual system. We review the latest insights about the topographic organization of monkey visual cortex and discuss the spatial relationships between retinotopy and category- and feature-selective clusters. We briefly discuss the functional layout of parietal and frontal cortex and continue with a summary of some fascinating functional and effective connectivity studies. Finally, we review recent comparative fMRI experiments and speculate about the future of nonhuman primate imaging. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Gravity influences the visual representation of object tilt in parietal cortex.

    Science.gov (United States)

    Rosenberg, Ari; Angelaki, Dora E

    2014-10-22

    Sensory systems encode the environment in egocentric (e.g., eye, head, or body) reference frames, creating inherently unstable representations that shift and rotate as we move. However, it is widely speculated that the brain transforms these signals into an allocentric, gravity-centered representation of the world that is stable and independent of the observer's spatial pose. Where and how this representation may be achieved is currently unknown. Here we demonstrate that a subpopulation of neurons in the macaque caudal intraparietal area (CIP) visually encodes object tilt in nonegocentric coordinates defined relative to the gravitational vector. Neuronal responses to the tilt of a visually presented planar surface were measured with the monkey in different spatial orientations (upright and rolled left/right ear down) and then compared. This revealed a continuum of representations in which planar tilt was encoded in a gravity-centered reference frame in approximately one-tenth of the comparisons, intermediate reference frames ranging between gravity-centered and egocentric in approximately two-tenths of the comparisons, and in an egocentric reference frame in less than half of the comparisons. Altogether, almost half of the comparisons revealed a shift in the preferred tilt and/or a gain change consistent with encoding object orientation in nonegocentric coordinates. Through neural network modeling, we further show that a purely gravity-centered representation of object tilt can be achieved directly from the population activity of CIP-like units. These results suggest that area CIP may play a key role in creating a stable, allocentric representation of the environment defined relative to an "earth-vertical" direction. Copyright © 2014 the authors 0270-6474/14/3414170-11$15.00/0.

  7. Medial parietal cortex activation related to attention control involving alcohol cues

    NARCIS (Netherlands)

    Gladwin, Thomas E.; ter Mors-Schulte, Mieke H. J.; Ridderinkhof, K. Richard; Wiers, Reinout W.

    2013-01-01

    Automatic attentional engagement toward and disengagement from alcohol cues play a role in alcohol use and dependence. In the current study, social drinkers performed a spatial cueing task designed to evoke conflict between such automatic processes and task instructions, a potentially important task

  8. Endogenous BDNF Is Required for Long-Term Memory Formation in the Rat Parietal Cortex

    Science.gov (United States)

    Alonso, Mariana; Bekinschtein, Pedro, Cammarota, Martin; Vianna, Monica R. M.; Izquierdo, Ivan; Medina, Jorge H.

    2005-01-01

    Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory…

  9. A key region in the human parietal cortex for processing proprioceptive hand feedback during reaching movements

    DEFF Research Database (Denmark)

    Reichenbach, Alexandra; Thielscher, Axel; Peer, Angelika

    2014-01-01

    of proprioceptive-only and of multi-sensory information about hand position when reaching for a visual target. TMS over two distinct stimulation sites elicited differential effects: TMS applied over the posterior part of the medial intraparietal sulcus (mIPS) compromised reaching accuracy when proprioception...... was the only sensory information available for correcting the reaching error. When visual feedback of the hand was available, TMS over the anterior intraparietal sulcus (aIPS) prolonged reaching time. Our results show for the first time the causal involvement of the posterior mIPS in processing proprioceptive...

  10. Physical experience leads to enhanced object perception in parietal cortex: Insights from knot tying

    NARCIS (Netherlands)

    Cross, E.S.; Cohen, N.R.; Hamilton, A.F.D.C.; Ramsey, R.; Wolford, G.; Grafton, S.T.

    2012-01-01

    What does it mean to "know" what an object is? Viewing objects from different categories (e.g., tools vs. animals) engages distinct brain regions, but it is unclear whether these differences reflect object categories themselves or the tendency to interact differently with objects from different

  11. Left Posterior Parietal Cortex Participates in Both Task Preparation and Episodic Retrieval

    OpenAIRE

    Phillips, Jeffrey S.; Velanova, Katerina; Wolk, David A.; Wheeler, Mark E.

    2009-01-01

    Optimal memory retrieval depends not only on the fidelity of stored information, but also on the attentional state of the subject. Factors such as mental preparedness to engage in stimulus processing can facilitate or hinder memory retrieval. The current study used functional magnetic resonance imaging (fMRI) to distinguish preparatory brain activity before episodic and semantic retrieval tasks from activity associated with retrieval itself. A catch-trial imaging paradigm permitted separation...

  12. The posterior parietal cortex as integrative hub for whisker sensorimotor information

    NARCIS (Netherlands)

    Mohan, Hemanth; de Haan, Roel; Mansvelder, Huibert D; de Kock, Christiaan P J

    2018-01-01

    Our daily life consists of a continuous interplay between incoming sensory information and outgoing motor plans. Particularly during goal-directed behavior and active exploration of the sensory environment, brain circuits are merging sensory and motor signals. This is referred to as sensorimotor

  13. Neural correlates and neural computations in posterior parietal cortex during perceptual decision-making

    Directory of Open Access Journals (Sweden)

    Alexander eHuk

    2012-10-01

    Full Text Available A recent line of work has found remarkable success in relating perceptual decision-making and the spiking activity in the macaque lateral intraparietal area (LIP. In this review, we focus on questions about the neural computations in LIP that are not answered by demonstrations of neural correlates of psychological processes. We highlight three areas of limitations in our current understanding of the precise neural computations that might underlie neural correlates of decisions: (1 empirical questions not yet answered by existing data; (2 implementation issues related to how neural circuits could actually implement the mechanisms suggested by both physiology and psychology; and (3 ecological constraints related to the use of well-controlled laboratory tasks and whether they provide an accurate window on sensorimotor computation. These issues motivate the adoption of a more general encoding-decoding framework that will be fruitful for more detailed contemplation of how neural computations in LIP relate to the formation of perceptual decisions.

  14. Lateral prefrontal cortex subregions make dissociable contributions during fluid reasoning.

    Science.gov (United States)

    Hampshire, Adam; Thompson, Russell; Duncan, John; Owen, Adrian M

    2011-01-01

    Reasoning is a key component of adaptable "executive" behavior and is known to depend on a network of frontal and parietal brain regions. However, the mechanisms by which this network supports reasoning and adaptable behavior remain poorly defined. Here, we examine the relationship between reasoning, executive control, and frontoparietal function in a series of nonverbal reasoning experiments. Our results demonstrate that, in accordance with previous studies, a network of frontal and parietal brain regions is recruited during reasoning. Our results also reveal that this network can be fractionated according to how different subregions respond when distinct reasoning demands are manipulated. While increased rule complexity modulates activity within a right lateralized network including the middle frontal gyrus and the superior parietal cortex, analogical reasoning demand-or the requirement to remap rules on to novel features-recruits the left inferior rostrolateral prefrontal cortex and the lateral occipital complex. In contrast, the posterior extent of the inferior frontal gyrus, associated with simpler executive demands, is not differentially sensitive to rule complexity or analogical demand. These findings accord well with the hypothesis that different reasoning demands are supported by different frontal and parietal subregions.

  15. Lateral Prefrontal Cortex Subregions Make Dissociable Contributions during Fluid Reasoning

    Science.gov (United States)

    Thompson, Russell; Duncan, John; Owen, Adrian M.

    2011-01-01

    Reasoning is a key component of adaptable “executive” behavior and is known to depend on a network of frontal and parietal brain regions. However, the mechanisms by which this network supports reasoning and adaptable behavior remain poorly defined. Here, we examine the relationship between reasoning, executive control, and frontoparietal function in a series of nonverbal reasoning experiments. Our results demonstrate that, in accordance with previous studies, a network of frontal and parietal brain regions is recruited during reasoning. Our results also reveal that this network can be fractionated according to how different subregions respond when distinct reasoning demands are manipulated. While increased rule complexity modulates activity within a right lateralized network including the middle frontal gyrus and the superior parietal cortex, analogical reasoning demand—or the requirement to remap rules on to novel features—recruits the left inferior rostrolateral prefrontal cortex and the lateral occipital complex. In contrast, the posterior extent of the inferior frontal gyrus, associated with simpler executive demands, is not differentially sensitive to rule complexity or analogical demand. These findings accord well with the hypothesis that different reasoning demands are supported by different frontal and parietal subregions. PMID:20483908

  16. Altered resting-state effective connectivity of fronto-parietal motor control systems on the primary motor network following stroke

    Science.gov (United States)

    Inman, Cory S.; James, G. Andrew; Hamann, Stephan; Rajendra, Justin K.; Pagnoni, Giuseppe; Butler, Andrew J.

    2011-01-01

    Previous brain imaging work suggests that stroke alters the effective connectivity (the influence neural regions exert upon each other) of motor execution networks. The present study examines the intrinsic effective connectivity of top-down motor control in stroke survivors (n=13) relative to healthy participants (n=12). Stroke survivors exhibited significant deficits in motor function, as assessed by the Fugl-Meyer Motor Assessment. We used structural equation modeling (SEM) of resting-state fMRI data to investigate the relationship between motor deficits and the intrinsic effective connectivity between brain regions involved in motor control and motor execution. An exploratory adaptation of SEM determined the optimal model of motor execution effective connectivity in healthy participants, and confirmatory SEM assessed stroke survivors’ fit to that model. We observed alterations in spontaneous resting-state effective connectivity from fronto-parietal guidance systems to the motor network in stroke survivors. More specifically, diminished connectivity was found in connections from the superior parietal cortex to primary motor cortex and supplementary motor cortex. Furthermore, the paths demonstrated large individual variance in stroke survivors but less variance in healthy participants. These findings suggest that characterizing the deficits in resting-state connectivity of top-down processes in stroke survivors may help optimize cognitive and physical rehabilitation therapies by individually targeting specific neural pathway. PMID:21839174

  17. No evidence for enhancements to visual working memory with transcranial direct current stimulation to prefrontal or posterior parietal cortices.

    Science.gov (United States)

    Robison, Matthew K; McGuirk, William P; Unsworth, Nash

    2017-08-01

    The present study examined the relative contributions of the prefrontal cortex (PFC) and posterior parietal cortex (PPC) to visual working memory. Evidence from a number of different techniques has led to the theory that the PFC controls access to working memory (i.e., filtering), determining which information is encoded and maintained for later use whereas the parietal cortex determines how much information is held at 1 given time, regardless of relevance (i.e., capacity; McNab & Klingberg, 2008; Vogel, McCollough, & Machizawa, 2005). To test this theory, we delivered transcranial DC stimulation (tDCS) to the right PFC and right PPC and measured visual working memory capacity and filtering abilities both during and immediately following stimulation. We observed no evidence that tDCS to either the PFC or PPC significantly improved visual working memory. Although the present results did not allow us to make firm theoretical conclusions about the roles of the PFC and PPC in working memory, the results add to the growing body of literature surrounding tDCS and its associated behavioral and neurophysiological effects. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. Altered functional connectivity of the dorsolateral prefrontal cortex in first-episode patients with major depressive disorder

    International Nuclear Information System (INIS)

    Ye, Ting; Peng, Jing; Nie, Binbin; Gao, Juan; Liu, Jiangtao; Li, Yang; Wang, Gang; Ma, Xin; Li, Kuncheng

    2012-01-01

    Background: The aim of this study was to investigate resting-state functional connectivity alteration of the right dorsolateral prefrontal cortex (DLPFC) in patients with first-episode major depressive disorder (MDD). Methods: Twenty-two first-episode MDD patients and thirty age-, gender- and education-matched healthy control subjects were enrolled. Rest state functional magnetic resonance images and structure magnetic resonance images were scanned. The functional connectivity analysis was done based on the result of voxel-based morphometry (VBM). And the right DLPFC was chosen as the seed region of interests (ROI), as its gray matter density (GMD) decreased in the MDD patients compared with controls and its GMD values were negative correlation with the Hamilton Depression Rating Scale (HDRS) scores. Results: Compared to healthy controls, the MDD patients showed increased functional connectivity with right the DLPFC in the left dorsal anterior cingulate cortex (ACC), left parahippocampal gyrus (PHG), thalamus and precentral gyrus. In contrast, there were decreased functional connectivity between the right DLPFC and right parietal lobe. Conclusions: By applying the VBM results to the functional connectivity analysis, the study suggested that abnormality of GMD in right DLPFC might be related to the functional connectivity alteration in the pathophysiology of MDD, which might be useful in further characterizing structure–function relations in this disorder.

  19. Altered functional connectivity of the dorsolateral prefrontal cortex in first-episode patients with major depressive disorder

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Ting, E-mail: yeting@ihep.ac.cn [Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Graduate School of Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Peng, Jing, E-mail: ppengjjing@sina.com.cn [Department of Radiology, Xuanwu Hospital of Capital Medical University, No. 45, Chang-Chun St, Xuanwu District, Beijing 100053 (China); Nie, Binbin, E-mail: niebb@ihep.ac.cn [Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Gao, Juan, E-mail: gaojuan@ihep.ac.cn [Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Graduate School of Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Liu, Jiangtao, E-mail: Liujiangtao813@sina.com [Department of Radiology, Xuanwu Hospital of Capital Medical University, No. 45, Chang-Chun St, Xuanwu District, Beijing 100053 (China); Li, Yang, E-mail: Liyang2007428@hotmail.com [Department of Psychiatry, Anding Hospital of Capital Medical University, No. 5, An Kang Hutong, Deshengmen wai, Xicheng District, Beijing 100088 (China); Wang, Gang, E-mail: gangwang@gmail.com [Department of Psychiatry, Anding Hospital of Capital Medical University, No. 5, An Kang Hutong, Deshengmen wai, Xicheng District, Beijing 100088 (China); Ma, Xin, E-mail: lijianshe@medmail.com.cn [Department of Psychiatry, Anding Hospital of Capital Medical University, No. 5, An Kang Hutong, Deshengmen wai, Xicheng District, Beijing 100088 (China); Li, Kuncheng [Department of Radiology, Xuanwu Hospital of Capital Medical University, No. 45, Chang-Chun St, Xuanwu District, Beijing 100053 (China); and others

    2012-12-15

    Background: The aim of this study was to investigate resting-state functional connectivity alteration of the right dorsolateral prefrontal cortex (DLPFC) in patients with first-episode major depressive disorder (MDD). Methods: Twenty-two first-episode MDD patients and thirty age-, gender- and education-matched healthy control subjects were enrolled. Rest state functional magnetic resonance images and structure magnetic resonance images were scanned. The functional connectivity analysis was done based on the result of voxel-based morphometry (VBM). And the right DLPFC was chosen as the seed region of interests (ROI), as its gray matter density (GMD) decreased in the MDD patients compared with controls and its GMD values were negative correlation with the Hamilton Depression Rating Scale (HDRS) scores. Results: Compared to healthy controls, the MDD patients showed increased functional connectivity with right the DLPFC in the left dorsal anterior cingulate cortex (ACC), left parahippocampal gyrus (PHG), thalamus and precentral gyrus. In contrast, there were decreased functional connectivity between the right DLPFC and right parietal lobe. Conclusions: By applying the VBM results to the functional connectivity analysis, the study suggested that abnormality of GMD in right DLPFC might be related to the functional connectivity alteration in the pathophysiology of MDD, which might be useful in further characterizing structure–function relations in this disorder.

  20. Bilateral parietal extradural metastatic ewing's sarcoma simulating acute epidural hematoma

    International Nuclear Information System (INIS)

    Aslam, E.; Imran, M.; Faridi, N.M.

    2006-01-01

    Sarcomas usually metastasize to lugs. The following case report describes an unusual metastasis of Ewing's sarcoma to extradural parietal region bilaterally. The primary was found at lower end of ulna. (author)

  1. Fronto-parietal contributions to phonological processes in successful artificial grammar learning

    Directory of Open Access Journals (Sweden)

    Dariya Goranskaya

    2016-11-01

    Full Text Available Sensitivity to regularities plays a crucial role in the acquisition of various linguistic features from spoken language input. Artificial grammar (AG learning paradigms explore pattern recognition abilities in a set of structured sequences (i.e. of syllables or letters. In the present study, we investigated the functional underpinnings of learning phonological regularities in auditorily presented syllable sequences. While previous neuroimaging studies either focused on functional differences between the processing of correct vs. incorrect sequences or between different levels of sequence complexity, here the focus is on the neural foundation of the actual learning success. During functional magnetic resonance imaging (fMRI, participants were exposed to a set of syllable sequences with an underlying phonological rule system, known to ensure performance differences between participants. We expected that successful learning and rule application would require phonological segmentation and phoneme comparison. As an outcome of four alternating learning and test fMRI sessions, participants split into successful learners and non-learners. Relative to non-learners, successful learners showed increased task-related activity in a fronto-parietal network of brain areas encompassing the left lateral premotor cortex as well as bilateral superior and inferior parietal cortices during both learning and rule application. These areas were previously associated with phonological segmentation, phoneme comparison and verbal working memory. Based on these activity patterns and the phonological strategies for rule acquisition and application, we argue that successful learning and processing of complex phonological rules in our paradigm is mediated via a fronto-parietal network for phonological processes.

  2. It's how you get there: Walking down a virtual alley activates premotor and parietal areas

    Directory of Open Access Journals (Sweden)

    Johanna eWagner

    2014-02-01

    Full Text Available Voluntary drive is crucial for motor learning, therefore we are interested in the role that motor planning plays in gait movements. In this study we examined the impact of an interactive Virtual Environment (VE feedback task on the EEG patterns during robot assisted walking. We compared walking in the VE modality to two control conditions: walking with a visual attention paradigm, in which visual stimuli were unrelated to the motor task; and walking with mirror feedback, in which participants observed their own movements. Eleven healthy participants were considered. Application of independent component analysis to the EEG revealed three independent component clusters in premotor and parietal areas showing increased activity during walking with the adaptive VE training paradigm compared to the control conditions. During the interactive VE walking task spectral power in frequency ranges 8-12Hz, 15-20Hz and 23-40Hz was significantly (p ≤ 0.05 decreased. This power decrease is interpreted as a correlate of an active cortical area. Furthermore activity in the premotor cortex revealed gait cycle related modulations significantly different (p ≤ 0.05 from baseline in the frequency range 23-40Hz during walking. These modulations were significantly (p ≤ 0.05 reduced depending on gait cycle phases in the interactive VE walking task compared to the control conditions.We demonstrate that premotor and parietal areas show increased activity during walking with the adaptive VE training paradigm, when compared to walking with mirror- and movement unrelated feedback. Previous research has related a premotor-parietal network to motor planning and motor intention. We argue that movement related interactive feedback enhances motor planning and motor intention. We hypothesize that this might improve gait recovery during rehabilitation.

  3. Orbitofrontal cortex contribution to working memory. N-back ERP study

    International Nuclear Information System (INIS)

    Nakao, Yoshiaki; Tamura, Toshiyo; Kodabashi, Atsushi; Fujimoto, Toshiro; Yarita, Masaru

    2011-01-01

    Remarkable progress in cognitive neuroscience has revealed the involvement of the prefrontal cortex and the orbitofrontal cortex in human working memory, but the orbitofrontal cortex is still one of the least understood regions in the human brain. To elucidate the contribution of the orbitofrontal cortex to human working memory, we studied electroencephalography (EEG) P300 activity in n-back task. We elicited early P3 around 300 ms and late P3 around 360 ms of P300 components in n-back event related potentials (ERP). The amplitudes of the respective peaks changed depending on the working memory load (0-back, 1-back, 2-back, 3-back). We used source analysis to evaluate the orbitofrontal cortex in P3 components. A source model was constructed with the sources seeded from fMRI meta-analysis of n-back task and additional sources in the orbitofrontal cortex and the visual cortex estimated with P100 and late P3 components in the n-back ERP. This source model had more than 99% of GOF (goodness of fit) in n-back ERP. It gave us an insight of brain activity at the positions where sources existed. Early P3 was mainly produced by the dorsolateral prefrontal cortex, the ventrolateral prefrontal cortex, the inferior parietal lobule, the medial posterior parietal and the visual cortex. Late P3 was mainly produced by the medial premotor, the lateral premotor, the frontal pole and the orbitofrontal cortex. The contribution of the frontal pole and the orbitofrontal cortex had peaks around 390 ms which were later than late P3 component. In this study, the method to evaluate the orbitofrontal cortex activity in n-back ERP was provided. Our results elicited the involvement of the orbitofrontal cortex in late P3 component of n-back ERP. (author)

  4. Parietal and early visual cortices encode working memory content across mental transformations.

    Science.gov (United States)

    Christophel, Thomas B; Cichy, Radoslaw M; Hebart, Martin N; Haynes, John-Dylan

    2015-02-01

    Active and flexible manipulations of memory contents "in the mind's eye" are believed to occur in a dedicated neural workspace, frequently referred to as visual working memory. Such a neural workspace should have two important properties: The ability to store sensory information across delay periods and the ability to flexibly transform sensory information. Here we used a combination of functional MRI and multivariate decoding to indentify such neural representations. Subjects were required to memorize a complex artificial pattern for an extended delay, then rotate the mental image as instructed by a cue and memorize this transformed pattern. We found that patterns of brain activity already in early visual areas and posterior parietal cortex encode not only the initially remembered image, but also the transformed contents after mental rotation. Our results thus suggest that the flexible and general neural workspace supporting visual working memory can be realized within posterior brain regions. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Reduced activation in lateral prefrontal cortex and anterior cingulate during attention and cognitive control functions in medication-naïve adolescents with depression compared to controls.

    Science.gov (United States)

    Halari, Rozmin; Simic, Mima; Pariante, Carmine M; Papadopoulos, Andrew; Cleare, Anthony; Brammer, Michael; Fombonne, Eric; Rubia, Katya

    2009-03-01

    There is increasing recognition of major depressive disorder (MDD) in adolescence. In adult MDD, abnormalities of fronto-striatal and fronto-cingulate circuitries mediating cognitive control functions have been implicated in the pathogenesis and been related to problems with controlling negative thoughts. No neuroimaging studies of cognitive control functions, however, exist in paediatric depression. This study investigated whether medication-naïve adolescents with MDD show abnormal brain activation of fronto-striatal and fronto-cingulate networks when performing tasks of attentional and cognitive control. Event-related functional magnetic resonance imaging was used to compare brain activation between 21 medication-naïve adolescents with a first-episode of MDD aged 14-17 years and 21 healthy adolescents, matched for handedness, age, sex, demographics and IQ. Activation paradigms were tasks of selective attention (Simon task), attentional switching (Switch task), and motor response inhibition and error detection (Stop task). In all three tasks, adolescents with depression compared to healthy controls demonstrated reduced activation in task-relevant right dorsolateral (DLPFC), inferior prefrontal cortex (IFC) and anterior cingulate gyrus (ACG). Additional areas of relatively reduced activation were in the parietal lobes during the Stop and Switch tasks, putamen, insula and temporal lobes during the Switch task and precuneus during the Simon task. This study shows first evidence that medication-naïve adolescents with MDD are characterised by abnormal function in ACG and right lateral prefrontal cortex during tasks of attention and performance monitoring, suggesting an early pathogenesis of these functional abnormalities attributed to MDD.

  6. Recency Effects in the Inferior Parietal Lobe during Verbal Recognition Memory

    Directory of Open Access Journals (Sweden)

    Bradley Russell Buchsbaum

    2011-07-01

    Full Text Available The most recently encountered information is often most easily remembered in psychological tests of memory. Recent investigations of the neural basis of such recency effects have shown that activation in the lateral inferior parietal cortex (LIPC tracks the recency of a probe item when subjects make recognition memory judgments. A key question regarding recency effects in the LIPC is whether they fundamentally reflect the storage (and strength of information in memory, or whether such effects are a consequence of task difficulty or an upswing in resting state network activity. Using functional magnetic resonance imaging (fMRI we show that recency effects in the LIPC are independent of the difficulty of recognition memory decisions, that they are not a by-product of an increase in resting state network activity, and that they appear to dissociate from regions known to be involved in verbal working memory maintenance. We conclude with a discussion of two alternative explanations – the memory strength and expectancy hypotheses, respectively -- of the parietal lobe recency effect.

  7. Hippocampal and posterior parietal contributions to developmental increases in visual short-term memory capacity.

    Science.gov (United States)

    von Allmen, David Yoh; Wurmitzer, Karoline; Klaver, Peter

    2014-10-01

    Developmental increases in visual short-term memory (VSTM) capacity have been associated with changes in attention processing limitations and changes in neural activity within neural networks including the posterior parietal cortex (PPC). A growing body of evidence suggests that the hippocampus plays a role in VSTM, but it is unknown whether the hippocampus contributes to the capacity increase across development. We investigated the functional development of the hippocampus and PPC in 57 children, adolescents and adults (age 8-27 years) who performed a visuo-spatial change detection task. A negative relationship between age and VSTM related activity was found in the right posterior hippocampus that was paralleled by a positive age-activity relationship in the right PPC. In the posterior hippocampus, VSTM related activity predicted individual capacity in children, whereas neural activity in the right anterior hippocampus predicted individual capacity in adults. The findings provide first evidence that VSTM development is supported by an integrated neural network that involves hippocampal and posterior parietal regions.

  8. Parietal disruption alters audiovisual binding in the sound-induced flash illusion.

    Science.gov (United States)

    Kamke, Marc R; Vieth, Harrison E; Cottrell, David; Mattingley, Jason B

    2012-09-01

    Selective attention and multisensory integration are fundamental to perception, but little is known about whether, or under what circumstances, these processes interact to shape conscious awareness. Here, we used transcranial magnetic stimulation (TMS) to investigate the causal role of attention-related brain networks in multisensory integration between visual and auditory stimuli in the sound-induced flash illusion. The flash illusion is a widely studied multisensory phenomenon in which a single flash of light is falsely perceived as multiple flashes in the presence of irrelevant sounds. We investigated the hypothesis that extrastriate regions involved in selective attention, specifically within the right parietal cortex, exert an influence on the multisensory integrative processes that cause the flash illusion. We found that disruption of the right angular gyrus, but not of the adjacent supramarginal gyrus or of a sensory control site, enhanced participants' veridical perception of the multisensory events, thereby reducing their susceptibility to the illusion. Our findings suggest that the same parietal networks that normally act to enhance perception of attended events also play a role in the binding of auditory and visual stimuli in the sound-induced flash illusion. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Prefrontal and parietal activity is modulated by the rule complexity of inductive reasoning and can be predicted by a cognitive model.

    Science.gov (United States)

    Jia, Xiuqin; Liang, Peipeng; Shi, Lin; Wang, Defeng; Li, Kuncheng

    2015-01-01

    In neuroimaging studies, increased task complexity can lead to increased activation in task-specific regions or to activation of additional regions. How the brain adapts to increased rule complexity during inductive reasoning remains unclear. In the current study, three types of problems were created: simple rule induction (i.e., SI, with rule complexity of 1), complex rule induction (i.e., CI, with rule complexity of 2), and perceptual control. Our findings revealed that increased activations accompany increased rule complexity in the right dorsal lateral prefrontal cortex (DLPFC) and medial posterior parietal cortex (precuneus). A cognitive model predicted both the behavioral and brain imaging results. The current findings suggest that neural activity in frontal and parietal regions is modulated by rule complexity, which may shed light on the neural mechanisms of inductive reasoning. Copyright © 2014. Published by Elsevier Ltd.

  10. Abnormal Baseline Brain Activity in Drug-Naïve Patients with Tourette Syndrome: A Resting-state fMRI Study

    Directory of Open Access Journals (Sweden)

    Yonghua eCui

    2014-01-01

    Full Text Available Tourette Syndrome (TS is a childhood-onset chronic disorder characterized by the presence of multiple motor and vocal tics. This study investigated spontaneous low-frequency fluctuations in TS patients during resting-state functional magnetic resonance imaging (fMRI scans. We obtained resting-state fMRI scans from seventeen drug-naïve TS children and fifteen demographically matched healthy children. We computed the amplitude of low frequency fluctuation (ALFF and fractional ALFF (fALFF of resting-state fMRI data to measure spontaneous brain activity, and assessed the between-group differences in ALFF/fALFF and the relationship between ALFF/fALFF and tic severity scores. Our results showed that the children with TS exhibited significantly decreased ALFF in the posterior cingulate gyrus/precuneus and bilateral parietal gyrus. fALFF was decreased in TS children in the anterior cingulated cortex, bilateral middle and superior frontal cortices and superior parietal lobule, and increased in the left putamen and bilateral thalamus. Moreover, we found significantly positive correlations between fALFF and tic severity scores in the right thalamus. Our study provides empirical evidence for abnormal spontaneous neuronal activity in TS patients, which may implicate the underlying neurophysiological mechanism in TS and demonstrate the possibility of applying ALFF/fALFF for clinical TS studies.

  11. NEURAL CORRELATES FOR APATHY: FRONTAL - PREFRONTAL AND PARIETAL CORTICAL - SUBCORTICAL CIRCUITS

    Directory of Open Access Journals (Sweden)

    Rita Moretti

    2016-12-01

    Full Text Available Apathy is an uncertain nosographical entity, which includes reduced motivation, abulia, decreased empathy, and lack of emotional invovlement; it is an important and heavy-burden clinical condition which strongly impacts in every day life events, affects the common daily living abilities, reduced the inner goal directed behavior, and gives the heaviest burden on caregivers. Is a quite common comorbidity of many neurological disease, However, there is no definite consensus on the role of apathy in clinical practice, no definite data on anatomical circuits involved in its development, and no definite instrument to detect it at bedside. As a general observation, the occurrence of apathy is connected to damage of prefrontal cortex (PFC and basal ganglia; emotional affective apathy may be related to the orbitomedial PFC and ventral striatum; cognitive apathy may be associated with dysfunction of lateral PFC and dorsal caudate nuclei; deficit of autoactivation may be due to bilateral lesions of the internal portion of globus pallidus, bilateral paramedian thalamic lesions, or the dorsomedial portion of PFC. On the other hand, apathy severity has been connected to neurofibrillary tangles density in the anterior cingulate gyrus and to grey matter atrophy in the anterior cingulate (ACC and in the left medial frontal cortex, confirmed by functional imaging studies. These neural networks are linked to projects, judjing and planning, execution and selection common actions, and through the basolateral amygdala and nucleus accumbens projects to the frontostriatal and to the dorsolateral prefrontal cortex. Therefore, an alteration of these circuitry caused a lack of insight, a reduction of decision-making strategies and a reduced speedness in action decsion, major resposnible for apathy. Emergent role concerns also the parietal cortex, with its direct action motivation control.We will discuss the importance of these circuits in different pathologies

  12. Reorganization of the Human Somatosensory Cortex in Hand Dystonia

    Directory of Open Access Journals (Sweden)

    Maria Jose Catalan

    2012-05-01

    Full Text Available Background and Purpose: Abnormalities of finger representations in the somatosensory cortex have been identified in patients with focal hand dystonia. Measuring blood flow with positron emission tomography (PET can be use to demonstrate functional localization of receptive fields. Methods: A vibratory stimulus was applied to the right thumb and little finger of six healthy volunteers and six patients with focal hand dystonia to map their receptive fields using H215O PET. Results: The cortical finger representations in the primary somatosensory cortex were closer to each other in patients than in normal subjects. No abnormalities were found in secondary somatosensory cortex, but the somatotopy there is less well distinguished. Conclusions: These data confirm prior electrophysiological and functional neuroimaging observations showing abnormalities of finger representations in somatosensory cortex of patients with focal hand dystonia.

  13. Downregulation of GABA[Subscript A] Receptor Protein Subunits a6, ß2, d, e, ?2, ?, and ?2 in Superior Frontal Cortex of Subjects with Autism

    Science.gov (United States)

    Fatemi, S. Hossein; Reutiman, Teri J.; Folsom, Timothy D.; Rustan, Oyvind G.; Rooney, Robert J.; Thuras, Paul D.

    2014-01-01

    We measured protein and mRNA levels for nine gamma-aminobutyric acid A (GABA[subscript A]) receptor subunits in three brain regions (cerebellum, superior frontal cortex, and parietal cortex) in subjects with autism versus matched controls. We observed changes in mRNA for a number of GABA[subscript A] and GABA[subscript B] subunits and overall…

  14. Abnormal interhemispheric connectivity in male psychopathic offenders.

    Science.gov (United States)

    Hoppenbrouwers, Sylco S; De Jesus, Danilo R; Sun, Yinming; Stirpe, Tania; Hofman, Dennis; McMaster, Jeff; Hughes, Ginny; Daskalakis, Zafiris J; Schutter, Dennis J L G

    2014-01-01

    Psychopathic offenders inevitably violate interpersonal norms and frequently resort to aggressive and criminal behaviour. The affective and cognitive deficits underlying these behaviours have been linked to abnormalities in functional interhemispheric connectivity. However, direct neurophysiological evidence for dysfunctional connectivity in psychopathic offenders is lacking. We used transcranial magnetic stimulation combined with electroencephalography to examine interhemispheric connectivity in the dorsolateral and motor cortex in a sample of psychopathic offenders and healthy controls. We also measured intracortical inhibition and facilitation over the left and right motor cortex to investigate the effects of local cortical processes on interhemispheric connectivity. We enrolled 17 psychopathic offenders and 14 controls in our study. Global abnormalities in right to left functional connectivity were observed in psychopathic offenders compared with controls. Furthermore, in contrast to controls, psychopathic offenders showed increased intracortical inhibition in the right, but not the left, hemisphere. The relatively small sample size limited the sensitivity to show that the abnormalities in interhemispheric connectivity were specifically related to the dorsolateral prefrontal cortex in psychopathic offenders. To our knowledge, this study provides the first neurophysiological evidence for abnormal interhemispheric connectivity in psychopathic offenders and may further our understanding of the disruptive antisocial behaviour of these offenders.

  15. Abnormal resting-state connectivity of motor and cognitive networks in early manifest Huntington's disease.

    Science.gov (United States)

    Wolf, R C; Sambataro, F; Vasic, N; Depping, M S; Thomann, P A; Landwehrmeyer, G B; Süssmuth, S D; Orth, M

    2014-11-01

    Functional magnetic resonance imaging (fMRI) of multiple neural networks during the brain's 'resting state' could facilitate biomarker development in patients with Huntington's disease (HD) and may provide new insights into the relationship between neural dysfunction and clinical symptoms. To date, however, very few studies have examined the functional integrity of multiple resting state networks (RSNs) in manifest HD, and even less is known about whether concomitant brain atrophy affects neural activity in patients. Using MRI, we investigated brain structure and RSN function in patients with early HD (n = 20) and healthy controls (n = 20). For resting-state fMRI data a group-independent component analysis identified spatiotemporally distinct patterns of motor and prefrontal RSNs of interest. We used voxel-based morphometry to assess regional brain atrophy, and 'biological parametric mapping' analyses to investigate the impact of atrophy on neural activity. Compared with controls, patients showed connectivity changes within distinct neural systems including lateral prefrontal, supplementary motor, thalamic, cingulate, temporal and parietal regions. In patients, supplementary motor area and cingulate cortex connectivity indices were associated with measures of motor function, whereas lateral prefrontal connectivity was associated with cognition. This study provides evidence for aberrant connectivity of RSNs associated with motor function and cognition in early manifest HD when controlling for brain atrophy. This suggests clinically relevant changes of RSN activity in the presence of HD-associated cortical and subcortical structural abnormalities.

  16. Temporal order processing of syllables in the left parietal lobe.

    Science.gov (United States)

    Moser, Dana; Baker, Julie M; Sanchez, Carmen E; Rorden, Chris; Fridriksson, Julius

    2009-10-07

    Speech processing requires the temporal parsing of syllable order. Individuals suffering from posterior left hemisphere brain injury often exhibit temporal processing deficits as well as language deficits. Although the right posterior inferior parietal lobe has been implicated in temporal order judgments (TOJs) of visual information, there is limited evidence to support the role of the left inferior parietal lobe (IPL) in processing syllable order. The purpose of this study was to examine whether the left inferior parietal lobe is recruited during temporal order judgments of speech stimuli. Functional magnetic resonance imaging data were collected on 14 normal participants while they completed the following forced-choice tasks: (1) syllable order of multisyllabic pseudowords, (2) syllable identification of single syllables, and (3) gender identification of both multisyllabic and monosyllabic speech stimuli. Results revealed increased neural recruitment in the left inferior parietal lobe when participants made judgments about syllable order compared with both syllable identification and gender identification. These findings suggest that the left inferior parietal lobe plays an important role in processing syllable order and support the hypothesized role of this region as an interface between auditory speech and the articulatory code. Furthermore, a breakdown in this interface may explain some components of the speech deficits observed after posterior damage to the left hemisphere.

  17. Functional segregation and integration within fronto-parietal networks.

    Science.gov (United States)

    Parlatini, Valeria; Radua, Joaquim; Dell'Acqua, Flavio; Leslie, Anoushka; Simmons, Andy; Murphy, Declan G; Catani, Marco; Thiebaut de Schotten, Michel

    2017-02-01

    Experimental data on monkeys and functional studies in humans support the existence of a complex fronto-parietal system activating for cognitive and motor tasks, which may be anatomically supported by the superior longitudinal fasciculus (SLF). Advanced tractography methods have recently allowed the separation of the three branches of the SLF but are not suitable for their functional investigation. In order to gather comprehensive information about the functional organisation of these fronto-parietal connections, we used an innovative method, which combined tractography of the SLF in the largest dataset so far (129 participants) with 14 meta-analyses of functional magnetic resonance imaging (fMRI) studies. We found that frontal and parietal functions can be clustered into a dorsal spatial/motor network associated with the SLF I, and a ventral non-spatial/motor network associated with the SLF III. Further, all the investigated functions activated a middle network mostly associated with the SLF II. Our findings suggest that dorsal and ventral fronto-parietal networks are segregated but also share regions of activation, which may support flexible response properties or conscious processing. In sum, our novel combined approach provided novel findings on the functional organisation of fronto-parietal networks, and may be successfully applied to other brain connections. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Distribution of catecholamines and serotonin in the rat cerebral cortex:

    International Nuclear Information System (INIS)

    Reader, T.A.

    1981-01-01

    The rat cerebral cortex was dissected in five regions and analyzed for the catecholamines noradrenaline, adrenaline and dopamine, and for the indoleamine seroton in using sensitive radioenzymatic assay methods with thin-layer-chromatography. The noradrenaline concentration was highest in the ventral cortex, lateral to the hypothalamus, had intermediate values for the prefrontal, frontal and parietal cortical areas and was lowest in the occipital cortex. Dopamine levels were also highest in the cortex lateral to the hypothalamus, and moderate in the prefrontal and frontal cortical areas, with the lowest values measured for the occipital cortex. The ratios dopamine/noradrenaline further support the hypothesis that they are independent transmitters. Traces of adrenaline were measured in all regions examined. The serotonin distribution was found to be non-homogeneous, with the highest values for the prefrontal cortex and ventral cortex lateral to the hypothalamus. The functional significance of these amines and their ratios are discussed in relation to their role as putative modulators of cortical neuronal excitability. (author)

  19. Differential Medial Temporal Lobe and Parietal Cortical Contributions to Real-world Autobiographical Episodic and Autobiographical Semantic Memory.

    Science.gov (United States)

    Brown, Thackery I; Rissman, Jesse; Chow, Tiffany E; Uncapher, Melina R; Wagner, Anthony D

    2018-04-18

    Autobiographical remembering can depend on two forms of memory: episodic (event) memory and autobiographical semantic memory (remembering personally relevant semantic knowledge, independent of recalling a specific experience). There is debate about the degree to which the neural signals that support episodic recollection relate to or build upon autobiographical semantic remembering. Pooling data from two fMRI studies of memory for real-world personal events, we investigated whether medial temporal lobe (MTL) and parietal subregions contribute to autobiographical episodic and semantic remembering. During scanning, participants made memory judgments about photograph sequences depicting past events from their life or from others' lives, and indicated whether memory was based on episodic or semantic knowledge. Results revealed several distinct functional patterns: activity in most MTL subregions was selectively associated with autobiographical episodic memory; the hippocampal tail, superior parietal lobule, and intraparietal sulcus were similarly engaged when memory was based on retrieval of an autobiographical episode or autobiographical semantic knowledge; and angular gyrus demonstrated a graded pattern, with activity declining from autobiographical recollection to autobiographical semantic remembering to correct rejections of novel events. Collectively, our data offer insights into MTL and parietal cortex functional organization, and elucidate circuitry that supports different forms of real-world autobiographical memory.

  20. Short parietal lobe connections of the human and monkey brain

    DEFF Research Database (Denmark)

    Catani, Marco; Robertsson, Naianna; Beyh, Ahmad

    2017-01-01

    projections were reconstructed for both species and results compared to identify similarities or differences in tract anatomy (i.e., trajectories and cortical projections). In addition, post-mortem dissections were performed in a human brain. The largest tract identified in both human and monkey brains...... and angular gyri of the inferior parietal lobule in humans but only to the supramarginal gyrus in the monkey brain. The third tract connects the postcentral gyrus to the anterior region of the superior parietal lobule and is more prominent in monkeys compared to humans. Finally, short U-shaped fibres...... and monkeys with some differences for those areas that have cytoarchitectonically distinct features in humans. The overall pattern of intraparietal connectivity supports the special role of the inferior parietal lobule in cognitive functions characteristic of humans....

  1. Mapping human temporal and parietal neuronal population activity and functional coupling during mathematical cognition

    Science.gov (United States)

    Daitch, Amy L.; Foster, Brett L.; Schrouff, Jessica; Rangarajan, Vinitha; Kaşikçi, Itır; Gattas, Sandra; Parvizi, Josef

    2016-01-01

    Brain areas within the lateral parietal cortex (LPC) and ventral temporal cortex (VTC) have been shown to code for abstract quantity representations and for symbolic numerical representations, respectively. To explore the fast dynamics of activity within each region and the interaction between them, we used electrocorticography recordings from 16 neurosurgical subjects implanted with grids of electrodes over these two regions and tracked the activity within and between the regions as subjects performed three different numerical tasks. Although our results reconfirm the presence of math-selective hubs within the VTC and LPC, we report here a remarkable heterogeneity of neural responses within each region at both millimeter and millisecond scales. Moreover, we show that the heterogeneity of response profiles within each hub mirrors the distinct patterns of functional coupling between them. Our results support the existence of multiple bidirectional functional loops operating between discrete populations of neurons within the VTC and LPC during the visual processing of numerals and the performance of arithmetic functions. These findings reveal information about the dynamics of numerical processing in the brain and also provide insight into the fine-grained functional architecture and connectivity within the human brain. PMID:27821758

  2. [Brodmann Areas 39 and 40: Human Parietal Association Area and Higher Cortical Function].

    Science.gov (United States)

    Sakurai, Yasuhisa

    2017-04-01

    The anatomy and function of the angular gyrus (Brodmann Area 39) and supramarginal gyrus (Brodmann Area 40) are described here. Both gyri constitute the inferior part of the parietal lobe. Association fibers from the angular gyrus project to the dorsolateral prefrontal cortex via the superior longitudinal fasciculus (SLF) II/arcuate fasciculus (AF), whereas those from the supramarginal gyrus project to the ventrolateral prefrontal cortex via SLF III/AF. Damage to the left angular gyrus causes kanji agraphia (lexical agraphia) and mild anomia, whereas damage to the left supramarginal gyrus causes kana alexia (phonological dyslexia) and kana agraphia (phonological agraphia). Damage to either gyrus causes Gerstmann's syndrome (finger agnosia, left-right disorientation, agraphia and acalculia) and verbal short-term memory impairment. "Angular alexia with agraphia" results from damage to the middle occipital gyrus posterior to the angular gyrus. Alexia and agraphia, with lesions in the angular or supramarginal gyrus, are characterized by kana transposition errors in reading words, which suggests the impairment of sequential phonological processing.

  3. Haptically Guided Grasping. fMRI Shows Right-Hemisphere Parietal Stimulus Encoding, and Bilateral Dorso-Ventral Parietal Gradients of Object- and Action-Related Processing during Grasp Execution.

    Science.gov (United States)

    Marangon, Mattia; Kubiak, Agnieszka; Króliczak, Gregory

    2015-01-01

    The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI) to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation, and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC) of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks). None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial) parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

  4. Cingulate, Frontal and Parietal Cortical Dysfunction in Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Bush, George

    2011-01-01

    Functional and structural neuroimaging have identified abnormalities of the brain that are likely to contribute to the neuropathophysiology of attention-deficit/hyperactivity disorder (ADHD). In particular, hypofunction of the brain regions comprising the cingulo-frontal-parietal (CFP) cognitive-attention network have been consistently observed across studies. These are major components of neural systems that are relevant to ADHD, including cognitive/attention networks, motor systems and reward/feedback-based processing systems. Moreover, these areas interact with other brain circuits that have been implicated in ADHD, such as the “default mode” resting state network. ADHD imaging data related to CFP network dysfunction will be selectively highlighted here to help facilitate its integration with the other information presented in this special issue. Together, these reviews will help shed light on the neurobiology of ADHD. PMID:21489409

  5. Visual cortex entrains to sign language.

    Science.gov (United States)

    Brookshire, Geoffrey; Lu, Jenny; Nusbaum, Howard C; Goldin-Meadow, Susan; Casasanto, Daniel

    2017-06-13

    Despite immense variability across languages, people can learn to understand any human language, spoken or signed. What neural mechanisms allow people to comprehend language across sensory modalities? When people listen to speech, electrophysiological oscillations in auditory cortex entrain to slow ([Formula: see text]8 Hz) fluctuations in the acoustic envelope. Entrainment to the speech envelope may reflect mechanisms specialized for auditory perception. Alternatively, flexible entrainment may be a general-purpose cortical mechanism that optimizes sensitivity to rhythmic information regardless of modality. Here, we test these proposals by examining cortical coherence to visual information in sign language. First, we develop a metric to quantify visual change over time. We find quasiperiodic fluctuations in sign language, characterized by lower frequencies than fluctuations in speech. Next, we test for entrainment of neural oscillations to visual change in sign language, using electroencephalography (EEG) in fluent speakers of American Sign Language (ASL) as they watch videos in ASL. We find significant cortical entrainment to visual oscillations in sign language sign is strongest over occipital and parietal cortex, in contrast to speech, where coherence is strongest over the auditory cortex. Nonsigners also show coherence to sign language, but entrainment at frontal sites is reduced relative to fluent signers. These results demonstrate that flexible cortical entrainment to language does not depend on neural processes that are specific to auditory speech perception. Low-frequency oscillatory entrainment may reflect a general cortical mechanism that maximizes sensitivity to informational peaks in time-varying signals.

  6. Amodal processing in human prefrontal cortex.

    Science.gov (United States)

    Tamber-Rosenau, Benjamin J; Dux, Paul E; Tombu, Michael N; Asplund, Christopher L; Marois, René

    2013-07-10

    Information enters the cortex via modality-specific sensory regions, whereas actions are produced by modality-specific motor regions. Intervening central stages of information processing map sensation to behavior. Humans perform this central processing in a flexible, abstract manner such that sensory information in any modality can lead to response via any motor system. Cognitive theories account for such flexible behavior by positing amodal central information processing (e.g., "central executive," Baddeley and Hitch, 1974; "supervisory attentional system," Norman and Shallice, 1986; "response selection bottleneck," Pashler, 1994). However, the extent to which brain regions embodying central mechanisms of information processing are amodal remains unclear. Here we apply multivariate pattern analysis to functional magnetic resonance imaging (fMRI) data to compare response selection, a cognitive process widely believed to recruit an amodal central resource across sensory and motor modalities. We show that most frontal and parietal cortical areas known to activate across a wide variety of tasks code modality, casting doubt on the notion that these regions embody a central processor devoid of modality representation. Importantly, regions of anterior insula and dorsolateral prefrontal cortex consistently failed to code modality across four experiments. However, these areas code at least one other task dimension, process (instantiated as response selection vs response execution), ensuring that failure to find coding of modality is not driven by insensitivity of multivariate pattern analysis in these regions. We conclude that abstract encoding of information modality is primarily a property of subregions of the prefrontal cortex.

  7. Investigation of Parietal Polysaccharides from Retama raetam Roots ...

    African Journals Online (AJOL)

    These results indicate the presence of the homogalacturonans and rhamnogalacturonans in pectin. This study constitutes the preliminary data obtained in the biochemical analysis of the parietal compounds of the roots of a species which grows in an arid area in comparison with those of its aerial parts. Keywords: Retama ...

  8. Significance of parietal projection in radiosotope scintigraphy of the brain

    International Nuclear Information System (INIS)

    Fomchenkov, E.P.

    1978-01-01

    The diagnostic value of the isotope scintigraphy of the brain in the parieal projection with the change of the dip angle of the gamma-chamber detector to the plane of the physiological horizontal was revealed. The observation was made on 100 patients with suspected presence of the volumetric process of the brain. Three variants of placing were studied: the parietal projection - standard (collimator plane parallel to the plane of physiological horizontal and strictly perpendicular to the sagittal plane); the placing with an angle of 30 deg between the detector plane and the physiological horizontal, opened at the front (posterio-parietal); placing with an angle of 30 deg between the detector plane and the physiological horizontal opened at the back (anterio-parietal). A comparative analysis of scintigrams with focal processes of the brain showed the largest informativeness of the proposed modification of the parietal projection in the form of a change of the dip angle of the gamma-chamber detector plane to the plane of the physiological horizontal opened at the back; this makes it possible to reveal more thoroughly the focus of the increased, pathological accumulation of the isotope in different parts of the skull, where the use of as standard placing is of small informativeness

  9. Subtotal ablation of parietal epithelial cells induces crescent formation.

    NARCIS (Netherlands)

    Sicking, E.M.; Fuss, A.; Uhlig, S.; Jirak, P.; Dijkman, H.; Wetzels, J.; Engel, D.R.; Urzynicok, T.; Heidenreich, S.; Kriz, W.; Kurts, C.; Ostendorf, T.; Floege, J.; Smeets, B.; Moeller, M.J.

    2012-01-01

    Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established

  10. Parietal epithelial cells and podocytes in glomerular diseases

    NARCIS (Netherlands)

    Smeets, B.; Moeller, M.J.

    2012-01-01

    In recent years, it has become apparent that parietal epithelial cells (PECs) play an important role within the renal glomerulus, in particular in diseased conditions. In this review, we examine current knowledge about the role of PECs and their interactions with podocytes in development and under

  11. Parietal cells-new perspectives in glomerular disease

    NARCIS (Netherlands)

    Miesen, L.; Steenbergen, E.; Smeets, B.

    2017-01-01

    In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman's capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and

  12. The regenerative potential of parietal epithelial cells in adult mice

    NARCIS (Netherlands)

    Berger, K.; Schulte, K.; Boor, P.; Kuppe, C.; Kuppevelt, T.H. van; Floege, J.; Smeets, B.; Moeller, M.J.

    2014-01-01

    Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman's capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically

  13. Abnormal functional connectivity of brain network hubs associated with symptom severity in treatment-naive patients with obsessive-compulsive disorder: A resting-state functional MRI study.

    Science.gov (United States)

    Tian, Lin; Meng, Chun; Jiang, Ying; Tang, Qunfeng; Wang, Shuai; Xie, Xiyao; Fu, Xiangshuai; Jin, Chunhui; Zhang, Fuquan; Wang, Jidong

    2016-04-03

    Abnormal brain networks have been observed in patients with obsessive-compulsive disorder (OCD). However, detailed network hub and connectivity changes remained unclear in treatment-naive patients with OCD. Here, we sought to determine whether patients show hub-related connectivity changes in their whole-brain functional networks. We used resting-state functional magnetic resonance imaging data and voxel-based graph-theoretic analysis to investigate functional connectivity strength and hubs of whole-brain networks in 29 treatment-naive patients with OCD and 29 age- and gender-matched healthy controls. Correlation analysis was applied for potential associations with OCD symptom severity. OCD selectively targeted brain regions of higher functional connectivity strength than the average including brain network hubs, mainly distributed in the cortico-striato-thalamo-cortical (CSTC) circuits and additionally parietal, occipital, temporal and cerebellar regions. Moreover, affected functional connectivity strength in the cerebellum, the medial orbitofrontal cortex and superior occipital cortex was significantly associated with global OCD symptom severity. Our results provide the evidence about OCD-related brain network hub changes, not only in the CSTC circuits but more distributed in whole brain networks. Data suggest that whole brain network hub analysis is useful for understanding the pathophysiology of OCD. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Magnetic stimulation of visual cortex impairs perceptual learning.

    Science.gov (United States)

    Baldassarre, Antonello; Capotosto, Paolo; Committeri, Giorgia; Corbetta, Maurizio

    2016-12-01

    The ability to learn and process visual stimuli more efficiently is important for survival. Previous neuroimaging studies have shown that perceptual learning on a shape identification task differently modulates activity in both frontal-parietal cortical regions and visual cortex (Sigman et al., 2005;Lewis et al., 2009). Specifically, fronto-parietal regions (i.e. intra parietal sulcus, pIPS) became less activated for trained as compared to untrained stimuli, while visual regions (i.e. V2d/V3 and LO) exhibited higher activation for familiar shape. Here, after the intensive training, we employed transcranial magnetic stimulation over both visual occipital and parietal regions, previously shown to be modulated, to investigate their causal role in learning the shape identification task. We report that interference with V2d/V3 and LO increased reaction times to learned stimuli as compared to pIPS and Sham control condition. Moreover, the impairment observed after stimulation over the two visual regions was positive correlated. These results strongly support the causal role of the visual network in the control of the perceptual learning. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Prefrontal, posterior parietal and sensorimotor network activity underlying speed control during walking

    Directory of Open Access Journals (Sweden)

    Thomas C Bulea

    2015-05-01

    Full Text Available Accumulating evidence suggests cortical circuits may contribute to control of human locomotion. Here, noninvasive electroencephalography (EEG recorded from able-bodied volunteers during a novel treadmill walking paradigm was used to assess neural correlates of walking. A systematic processing method, including a recently developed subspace reconstruction algorithm, reduced movement-related EEG artifact prior to independent component analysis and dipole source localization. We quantified cortical activity while participants tracked slow and fast target speeds across two treadmill conditions: an active mode that adjusted belt speed based on user movements and a passive mode reflecting a typical treadmill. Our results reveal frequency specific, multi-focal task related changes in cortical oscillations elicited by active walking. Low γ band power, localized to the prefrontal and posterior parietal cortices, was significantly increased during double support and early swing phases, critical points in the gait cycle since the active controller adjusted speed based on pelvis position and swing foot velocity. These phasic γ band synchronizations provide evidence that prefrontal and posterior parietal networks, previously implicated in visuo-spatial and somotosensory integration, are engaged to enhance lower limb control during gait. Sustained μ and β band desynchronization within sensorimotor cortex, a neural correlate for movement, was observed during walking thereby validating our methods for isolating cortical activity. Our results also demonstrate the utility of EEG recorded during locomotion for probing the multi-regional cortical networks which underpin its execution. For example, the cortical network engagement elicited by the active treadmill suggests that it may enhance neuroplasticity for more effective motor training.

  16. Development of rostral inferior parietal lobule area functional connectivity from late childhood to early adulthood.

    Science.gov (United States)

    Wang, Mengxing; Zhang, Jilei; Dong, Guangheng; Zhang, Hui; Lu, Haifeng; Du, Xiaoxia

    2017-06-01

    Although the mirror neuron system (MNS) has been extensively studied in monkeys and adult humans, very little is known about its development. Previous studies suggest that the MNS is present by infancy and that the brain and MNS-related cognitive abilities (such as language, empathy, and imitation learning) continue to develop after childhood. In humans, the PFt area of the inferior parietal lobule (IPL) seems to particularly correlate with the functional properties of the PF area in primates, which contains mirror neurons. However, little is known about the functional connectivity (FC) of the PFt area with other brain areas and whether these networks change over time. Here, we investigated the FC development of the PFt area-based network in 59 healthy subjects aged 7-26 years at resting-state to study brain development from late childhood through adolescence to early adulthood. The bilateral PFt showed similar core FC networks, which included the frontal lobe, the cingulate gyri, the insula, the somatosensory cortex, the precuneus, the superior and inferior parietal lobules, the temporal lobe, and the cerebellum posterior lobes. Furthermore, the FC between the left PFt and the left IPL exhibited a significantly positive correlation with age, and the FC between the left PFt and the right postcentral gyrus exhibited a significantly negative correlation with age. In addition, the FC between the right PFt and the right putamen exhibited a significantly negative correlation with age. Our findings suggest that the PFt area-based network develops and is reorganized with age. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

  17. Dissociated roles of the parietal and frontal cortices in the scope and control of attention during visual working memory.

    Science.gov (United States)

    Li, Siyao; Cai, Ying; Liu, Jing; Li, Dawei; Feng, Zifang; Chen, Chuansheng; Xue, Gui

    2017-04-01

    Mounting evidence suggests that multiple mechanisms underlie working memory capacity. Using transcranial direct current stimulation (tDCS), the current study aimed to provide causal evidence for the neural dissociation of two mechanisms underlying visual working memory (WM) capacity, namely, the scope and control of attention. A change detection task with distractors was used, where a number of colored bars (i.e., two red bars, four red bars, or two red plus two blue bars) were presented on both sides (Experiment 1) or the center (Experiment 2) of the screen for 100ms, and participants were instructed to remember the red bars and to ignore the blue bars (in both Experiments), as well as to ignore the stimuli on the un-cued side (Experiment 1 only). In both experiments, participants finished three sessions of the task after 15min of 1.5mA anodal tDCS administered on the right prefrontal cortex (PFC), the right posterior parietal cortex (PPC), and the primary visual cortex (VC), respectively. The VC stimulation served as an active control condition. We found that compared to stimulation on the VC, stimulation on the right PPC specifically increased the visual WM capacity under the no-distractor condition (i.e., 4 red bars), whereas stimulation on the right PFC specifically increased the visual WM capacity under the distractor condition (i.e., 2 red bars plus 2 blue bars). These results suggest that the PPC and PFC are involved in the scope and control of attention, respectively. We further showed that compared to central presentation of the stimuli (Experiment 2), bilateral presentation of the stimuli (on both sides of the fixation in Experiment 1) led to an additional demand for attention control. Our results emphasize the dissociated roles of the frontal and parietal lobes in visual WM capacity, and provide a deeper understanding of the neural mechanisms of WM. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Bilateral front-parietal polymicrogyria accompanied by cobblestone lissencephaly: 3T MR imaging findings of a case

    International Nuclear Information System (INIS)

    Bozkurt, Y.; Battal, B.; Ozcan, E.; Kocaoglu, M.

    2012-01-01

    Full text: Background: The cerebral cortex develops in three overlapping stages: cell proliferation, neuronal migration, and cortical organization. Lissencephaly (smooth brain) is a severe malformation of the cerebral cortex that results from impaired neuronal migration. Polymicrogyria is a disorder of late migration or cortical organization, and supposed to reflect a disruption of normal neuronal migration with subsequent disordered cortical organization. A combination of cobblestone lissencephaly and polymicrogyria is very rare in the same patient's brain. Objective: To present clinical and 3T magnetic resonance (MR) imaging findings of a 17-year-old male with bilateral fronto-parietal polimicrogyria accompanied by cobblestone lissencaphaly. Materials and methods: A 17-year-old male who had seizures and involuntary muscular spasm from birth, was referred to our Hospital. The patient was evaluated by a complete history, physical examination, a laboratory work-up, and cranial MR examination for evaluate the central nervous system. Results: A sharp wave paroxysm in the left temporal area was observed in the electroencephalogram (EEG). The neurological examination of our patient was normal. A slight increase have seen in the aspartate aminotransferase (SGOT) levels. The other biochemical tests were found to be normal. Cranial MR imaging showed an irregular nodular cortex with hypomyelination of the white matter at the lateral and posterior part of the right occipital lobe. We also observed the changes compatible with polymicrogyria in a large area of the medial parts of the bilateral temporal and parietal lobes. Conclusion: The role of radiological modalities for diagnosis of cortical formation disorders are very important. MR imaging are fairly useful for evaluation of these anomalies

  19. Separating recognition processes of declarative memory via anodal tDCS: boosting old item recognition by temporal and new item detection by parietal stimulation.

    Science.gov (United States)

    Pisoni, Alberto; Turi, Zsolt; Raithel, Almuth; Ambrus, Géza Gergely; Alekseichuk, Ivan; Schacht, Annekathrin; Paulus, Walter; Antal, Andrea

    2015-01-01

    There is emerging evidence from imaging studies that parietal and temporal cortices act together to achieve successful recognition of declarative information; nevertheless, the precise role of these regions remains elusive. To evaluate the role of these brain areas in declarative memory retrieval, we applied bilateral tDCS, with anode over the left and cathode over the right parietal or temporal cortices separately, during the recognition phase of a verbal learning paradigm using a balanced old-new decision task. In a parallel group design, we tested three different groups of healthy adults, matched for demographic and neurocognitive status: two groups received bilateral active stimulation of either the parietal or the temporal cortex, while a third group received sham stimulation. Accuracy, discriminability index (d') and reaction times of recognition memory performance were measurements of interest. The d' sensitivity index and accuracy percentage improved in both active stimulation groups, as compared with the sham one, while reaction times remained unaffected. Moreover, the analysis of accuracy revealed a different effect of tDCS for old and new item recognition. While the temporal group showed enhanced performance for old item recognition, the parietal group was better at correctly recognising new ones. Our results support an active role of both of these areas in memory retrieval, possibly underpinning different stages of the recognition process.

  20. Urine - abnormal color

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003139.htm Urine - abnormal color To use the sharing features on this page, please enable JavaScript. The usual color of urine is straw-yellow. Abnormally colored urine ...

  1. Tooth - abnormal colors

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003065.htm Tooth - abnormal colors To use the sharing features on this page, please enable JavaScript. Abnormal tooth color is any color other than white to yellowish- ...

  2. Abnormal uterine bleeding

    Science.gov (United States)

    Anovulatory bleeding; Abnormal uterine bleeding - hormonal; Polymenorrhea - dysfunctional uterine bleeding ... ACOG committee opinion no. 557: Management of acute abnormal uterine bleeding in nonpregnant reproductive-aged women. Reaffirmed 2015. www. ...

  3. Mapping visual cortex in monkeys and humans using surface-based atlases

    Science.gov (United States)

    Van Essen, D. C.; Lewis, J. W.; Drury, H. A.; Hadjikhani, N.; Tootell, R. B.; Bakircioglu, M.; Miller, M. I.

    2001-01-01

    We have used surface-based atlases of the cerebral cortex to analyze the functional organization of visual cortex in humans and macaque monkeys. The macaque atlas contains multiple partitioning schemes for visual cortex, including a probabilistic atlas of visual areas derived from a recent architectonic study, plus summary schemes that reflect a combination of physiological and anatomical evidence. The human atlas includes a probabilistic map of eight topographically organized visual areas recently mapped using functional MRI. To facilitate comparisons between species, we used surface-based warping to bring functional and geographic landmarks on the macaque map into register with corresponding landmarks on the human map. The results suggest that extrastriate visual cortex outside the known topographically organized areas is dramatically expanded in human compared to macaque cortex, particularly in the parietal lobe.

  4. Effect of camphor essential oil on rat cerebral cortex activity as manifested by fractal dimension changes

    Directory of Open Access Journals (Sweden)

    Grbić G.

    2008-01-01

    Full Text Available The aim of our study was to investigate the effect of camphor essential oil on rat cerebral cortex activity by fractal analysis. Fractal dimension (FD values of the parietal electrocortical activity were calculated before and after intra-peritoneal administration of camphor essential oil (450-675 μl/kg in anesthetized rats. Camphor oil induced seizure-like activity with single and multiple spiking of high amplitudes in the parietal electrocorticogram and occasional clonic limb convulsions. The FD values of cortical activity after camphor oil administration increased on the average. Only FD values of cortical ECoG sequences were lower than those before camphor oil administration.

  5. Parietal seeding of unsuspected gallbladder carcinoma after laparoscopic cholecystectomy.

    Science.gov (United States)

    Marmorale, C; Scibé, R; Siquini, W; Massa, M; Brunelli, A; Landi, E

    1998-01-01

    Laparoscopic cholecystectomy (VALC) represents the treatment of choice for the symptomatic gallstones. However the occurrence of an adenocarcinoma of the gallbladder results a controindication for this surgical technique. We present a case of a 52 years old woman who underwent a VALC; histology revealed a gallbladder adenocarcinoma. For this reason the patient underwent a second operation that is right hepatic trisegmentectomy. Six months later the patient presented with a parietal recurrence at the extraction site of the gallbladder. We discuss the possible mechanism responsible for carcinomatous dissemination during laparoscopic surgery and we raccommend the use of some procedures in order to limit the risk and eventually to treat a neoplastic parietal seeding. These complications suggest the problem about the utility and the future played by video assisted laparoscopic surgery in the diagnosis and treatment of intraabdominal malignancies.

  6. Kinesthetic alexia due to left parietal lobe lesions.

    Science.gov (United States)

    Ihori, Nami; Kawamura, Mitsuru; Araki, Shigeo; Kawachi, Juro

    2002-01-01

    To investigate the neuropsychological mechanisms of kinesthetic alexia, we asked 7 patients who showed kinesthetic alexia with preserved visual reading after damage to the left parietal region to perform tasks consisting of kinesthetic written reproduction (writing down the same letter as the kinesthetic stimulus), kinesthetic reading aloud, visual written reproduction (copying letters), and visual reading aloud of hiragana (Japanese phonograms). We compared the performance in these tasks and the lesion sites in each patient. The results suggested that deficits in any one of the following functions might cause kinesthetic alexia: (1) the retrieval of kinesthetic images (motor engrams) of characters from kinesthetic stimuli, (2) kinesthetic images themselves, (3) access to cross-modal association from kinesthetic images, and (4) cross-modal association itself (retrieval of auditory and visual images from kinesthetic images of characters). Each of these factors seemed to be related to different lesion sites in the left parietal lobe. Copyright 2002 S. Karger AG, Basel

  7. Cognitive correlates of neuroimaging abnormalities in the onset of schizophrenia: A case report

    OpenAIRE

    Grassi, Silvia; Orsenigo, Giulia; Serati, Marta; Caletti, Elisabetta; Altamura, Alfredo Carlo; Buoli, Massimiliano

    2017-01-01

    Increasing evidence shows that cognitive impairment and brain abnormalities can appear early in the first episodes of schizophrenia, but it is currently debated how brain changes can correlate with clinical presentation of schizophrenic patients. Of note, this report describes the case of a young schizophrenic male presenting parietal magnetic resonance/positron emission tomography abnormalities and cognitive impairment, documented by specific neuropsychological tests. In our knowledge only f...

  8. Neuronal oscillations form parietal/frontal networks during contour integration.

    Science.gov (United States)

    Castellano, Marta; Plöchl, Michael; Vicente, Raul; Pipa, Gordon

    2014-01-01

    The ability to integrate visual features into a global coherent percept that can be further categorized and manipulated are fundamental abilities of the neural system. While the processing of visual information involves activation of early visual cortices, the recruitment of parietal and frontal cortices has been shown to be crucial for perceptual processes. Yet is it not clear how both cortical and long-range oscillatory activity leads to the integration of visual features into a coherent percept. Here, we will investigate perceptual grouping through the analysis of a contour categorization task, where the local elements that form contour must be linked into a coherent structure, which is then further processed and manipulated to perform the categorization task. The contour formation in our visual stimulus is a dynamic process where, for the first time, visual perception of contours is disentangled from the onset of visual stimulation or from motor preparation, cognitive processes that until now have been behaviorally attached to perceptual processes. Our main finding is that, while local and long-range synchronization at several frequencies seem to be an ongoing phenomena, categorization of a contour could only be predicted through local oscillatory activity within parietal/frontal sources, which in turn, would synchronize at gamma (>30 Hz) frequency. Simultaneously, fronto-parietal beta (13-30 Hz) phase locking forms a network spanning across neural sources that are not category specific. Both long range networks, i.e., the gamma network that is category specific, and the beta network that is not category specific, are functionally distinct but spatially overlapping. Altogether, we show that a critical mechanism underlying contour categorization involves oscillatory activity within parietal/frontal cortices, as well as its synchronization across distal cortical sites.

  9. Parietal cells?new perspectives in glomerular disease

    OpenAIRE

    Miesen, Laura; Steenbergen, Eric; Smeets, Bart

    2017-01-01

    In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman?s capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and podocytes have a common mesenchymal origin and are the result of divergent differentiation during embryogenesis. Podocytes and PTECs are highly differentiated cells with well-established functions pertain...

  10. Pneumothorax simulated by detachment of parietal pleura associated with pneumomediastinum

    International Nuclear Information System (INIS)

    Rozeik, C.; Kotterer, O.; Deininger, H.K.

    1994-01-01

    We report a case of blunt chest trauma, where findings on repeated conventional chest radiographs were compatible with pneumothorax developing after 2 days of mechanical high-pressure ventilation. CT showed that the appearance was due to a detachment of the parietal pleura along the lateral, mediastinal and diaphragmatic boundaries of the lungs, imitating a pneumothorax. The case report illustrates the key role of CT in the differential diagnosis of epipleural interstitial air collection versus pneumothorax. (orig./MG)

  11. Pneumothorax simulated by detachment of parietal pleura associated with pneumomediastinum

    Energy Technology Data Exchange (ETDEWEB)

    Rozeik, C. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany); Kotterer, O. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany); Deininger, H.K. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany)

    1994-10-01

    We report a case of blunt chest trauma, where findings on repeated conventional chest radiographs were compatible with pneumothorax developing after 2 days of mechanical high-pressure ventilation. CT showed that the appearance was due to a detachment of the parietal pleura along the lateral, mediastinal and diaphragmatic boundaries of the lungs, imitating a pneumothorax. The case report illustrates the key role of CT in the differential diagnosis of epipleural interstitial air collection versus pneumothorax. (orig./MG)

  12. Glomerular parietal epithelial cells in kidney physiology, pathology, and repair

    OpenAIRE

    Shankland, Stuart J.; Anders, Hans-Joachim; Romagnani, Paola

    2013-01-01

    Purpose of review We have summarized recently published glomerular parietal epithelial cell (PEC) research, focusing on their roles in glomerular development and physiology, and in certain glomerular diseases. The rationale is that PECs have been largely ignored until the recent availability of cell lineage tracing studies, human and murine PEC culture systems, and potential therapeutic interventions of PECs. Recent findings Several new paradigms involving PECs have emerged demonstrating thei...

  13. The Regenerative Potential of Parietal Epithelial Cells in Adult Mice

    OpenAIRE

    Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H.; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J.

    2014-01-01

    Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman’s capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glo...

  14. Fetal frontal cortex transplant (14C) 2-deoxyglucose uptake and histology: survival in cavities of host rat brain motor cortex

    International Nuclear Information System (INIS)

    Sharp, F.R.; Gonzalez, M.F.

    1984-01-01

    Fetal frontal neocortex from 18-day-old rat embryonic brain was transplanted into cavities in 30-day-old host motor cortex. Sixty days after transplantation, 5 of 15 transplanted rats had surviving fetal transplants. The fetal cortex transplants were physically attached to the host brain, completely filled the original cavity, and had numerous surviving cells including pyramidal neurons. Cell lamination within the fetal transplant was abnormal. The ( 14 C) 2-deoxyglucose uptake of all five of the fetal neocortex transplants was less than adjacent cortex and contralateral host motor-sensory cortex, but more than adjacent corpus callosum white matter. The results indicate that fetal frontal neocortex can be transplanted into damaged rat motor cortex. The metabolic rate of the transplants suggests they could be partially functional

  15. Abnormalities in cortical gray matter density in borderline personality disorder

    Science.gov (United States)

    Rossi, Roberta; Lanfredi, Mariangela; Pievani, Michela; Boccardi, Marina; Rasser, Paul E; Thompson, Paul M; Cavedo, Enrica; Cotelli, Maria; Rosini, Sandra; Beneduce, Rossella; Bignotti, Stefano; Magni, Laura R; Rillosi, Luciana; Magnaldi, Silvia; Cobelli, Milena; Rossi, Giuseppe; Frisoni, Giovanni B

    2015-01-01

    Background Borderline personality disorder (BPD) is a chronic condition with a strong impact on patients‘ affective,cognitive and social functioning. Neuroimaging techniques offer invaluable tools to understand the biological substrate of the disease. We aimed to investigate gray matter alterations over the whole cortex in a group of Borderline Personality Disorder (BPD) patients compared to healthy controls (HC). Methods Magnetic resonance-based cortical pattern matching was used to assess cortical gray matter density (GMD) in 26 BPD patients and in their age- and sex-matched HC (age: 38±11; females: 16, 61%). Results BPD patients showed widespread lower cortical GMD compared to HC (4% difference) with peaks of lower density located in the dorsal frontal cortex, in the orbitofrontal cortex, the anterior and posterior cingulate, the right parietal lobe, the temporal lobe (medial temporal cortex and fusiform gyrus) and in the visual cortex (p<0.005). Our BPD subjects displayed a symmetric distribution of anomalies in the dorsal aspect of the cortical mantle, but a wider involvement of the left hemisphere in the mesial aspect in terms of lower density. A few restricted regions of higher density were detected in the right hemisphere. All regions remained significant after correction for multiple comparisons via permutation testing. Conclusions BPD patients feature specific morphology of the cerebral structures involved in cognitive and emotional processing and social cognition/mentalization, consistent with clinical and functional data. PMID:25561291

  16. Evaluation of glucose metabolic abnormality in postlingually deaf patients using F-18-FDG positron emission tomography and statistical parametric mapping

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Sung; Lee, Dong Soo; Oh, Seung Ha; Kim, Chong Sun; Park, Kwang Suk; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2000-07-01

    We have previously reported the prognostic relevance of cross-modal cortical plasticity in prelingual deaf patients revealed by F-18-FDG PET and SPM analysis. In this study, we investigated metabolic abnormality in postlingual deaf patients, whose clinical features are different from prelingual deafness. Nine postlingual deaf patients (age: 30.5 {+-}14.0) were performed on F-18-FDG brain PET. We compared their PET images with those of age-matched 20 normal controls (age: 27.1 {+-}8.6), and performed correlation analysis to investigate the relationship between glucose metabolism and deaf duration using SPM99. Glucose metabolism of deaf patients was significantly (p<0.05, corrected) decreased in both anterior cingulate, inferior frontal cortices, and superior temporal cortices, and left hippocampus. Metabolism in both superior temporal cortices and association area in inferior parietal cortices showed significant (p<0.01, uncorrected) positive correlation with deaf duration. Decreased metabolism in hippocampus accompanied with hypometabolism in auditory related areas can be explained by recent finding of anatomical connectivity between them, and may be the evidence indicating their functional connectivity. Metabolism recovery in auditory cortex after long deaf duration suggests that cortical plasticity takes place also in postlingual deafness.

  17. Evaluation of glucose metabolic abnormality in postlingually deaf patients using F-18-FDG positron emission tomography and statistical parametric mapping

    International Nuclear Information System (INIS)

    Lee, Jae Sung; Lee, Dong Soo; Oh, Seung Ha; Kim, Chong Sun; Park, Kwang Suk; Chung, June Key; Lee, Myung Chul

    2000-01-01

    We have previously reported the prognostic relevance of cross-modal cortical plasticity in prelingual deaf patients revealed by F-18-FDG PET and SPM analysis. In this study, we investigated metabolic abnormality in postlingual deaf patients, whose clinical features are different from prelingual deafness. Nine postlingual deaf patients (age: 30.5 ±14.0) were performed on F-18-FDG brain PET. We compared their PET images with those of age-matched 20 normal controls (age: 27.1 ±8.6), and performed correlation analysis to investigate the relationship between glucose metabolism and deaf duration using SPM99. Glucose metabolism of deaf patients was significantly (p<0.05, corrected) decreased in both anterior cingulate, inferior frontal cortices, and superior temporal cortices, and left hippocampus. Metabolism in both superior temporal cortices and association area in inferior parietal cortices showed significant (p<0.01, uncorrected) positive correlation with deaf duration. Decreased metabolism in hippocampus accompanied with hypometabolism in auditory related areas can be explained by recent finding of anatomical connectivity between them, and may be the evidence indicating their functional connectivity. Metabolism recovery in auditory cortex after long deaf duration suggests that cortical plasticity takes place also in postlingual deafness

  18. The role of human parietal area 7A as a link between sequencing in hand actions and in overt speech production

    Directory of Open Access Journals (Sweden)

    Stefan eHeim

    2012-12-01

    Full Text Available Research on the evolutionary basis of the human language faculty has proposed the mirror neuron system as a link between motor processing and speech development. Consequently, most work has focussed on the left inferior frontal cortex, in particular Broca's region, and the left inferior parietal cortex. However, the direct link between planning of hand motor and speech actions remains to be elucidated. Thus, the present study investigated whether sequencing of hand motor actions vs. speech motor actions has a common neural denominator. For the hand motor task, 25 subjects performed single, repeated, or sequenced button presses with either the left or right hand. The speech task was in analogy; the same subjects produced the syllable "po" once or repeatedly, or a sequence of different syllables (po-pi-po. Speech motor vs. hand motor effectors resulted in increased perisylvian activation including Broca's region (left area 44 and areas medially adjacent to left area 45. In contrast, common activation for sequenced vs. repeated production of button presses and syllables revealed the effector-independent involvement of left area 7A in the superior parietal lobule (SPL in sequencing. These data demonstrate that sequencing of vocal gestures, an important precondition for ordered utterances and ultimately human speech, shares area 7A, rather than inferior parietal regions, as a common cortical module with hand motor sequencing. Interestingly, area 7A has previously also been shown to be involved in the observation of hand and non-hand actions. In combination with the literature, the present data thus suggest a distinction between area 44, which is specifically recruited for (cognitive aspects of speech, and SPL area 7A for general aspects of motor sequencing. In sum, the study demonstrates a yet little considered role of the superior parietal lobule in the origins of speech, and may be discussed in the light of embodiment of speech and language in the

  19. Functional development of fronto-striato-parietal networks associated with time perception

    Directory of Open Access Journals (Sweden)

    Anna eSmith

    2011-11-01

    Full Text Available Compared to our understanding of the functional maturation of executive functions, little is known about the neurofunctional development of perceptive functions. Time perception develops during late adolescence, underpinning many functions including motor and verbal processing, as well as late maturing higher order cognitive skills such as forward planning and future-related decision-making. Nothing, however, is known about the neurofunctional changes associated with time perception from childhood to adulthood. Using functional magnetic resonance imaging we explored the effects of age on the brain activation and functional connectivity of 32 male participants from 10 to 53 years of age during a time discrimination task that required the discrimination of temporal intervals of seconds differing by several hundred milliseconds. Increasing development was associated with progressive activation increases within left lateralised dorsolateral and inferior fronto-parieto-striato-thalamic brain regions. Furthermore, despite comparable task performance, adults showed increased functional connectivity between inferior/dorsolateral interhemispheric fronto-frontal activation as well as between inferior fronto-parietal regions compared with adolescents. Activation in caudate, specifically, was associated with both increasing age and better temporal discrimination. Progressive decreases in activation with age were observed in ventromedial prefrontal cortex, limbic regions and cerebellum. The findings demonstrate age-dependent developmentally dissociated neural networks for time discrimination. With increasing age there is progressive recruitment of later maturing left hemispheric and lateralised fronto-parieto-striato-thalamic networks, known to mediate time discrimination in adults, while earlier developing brain regions such as ventromedial prefrontal cortex, limbic and paralimbic areas and cerebellum subserve fine-temporal processing functions in children

  20. Differential effects of parietal and frontal inactivations on reaction times distributions in a visual search task

    Directory of Open Access Journals (Sweden)

    Claire eWardak

    2012-06-01

    Full Text Available The posterior parietal cortex participates to numerous cognitive functions, from perceptual to attentional and decisional processes. However, the same functions have also been attributed to the frontal cortex. We previously conducted a series of reversible inactivations of the lateral intraparietal area (LIP and of the frontal eye field (FEF in the monkey which showed impairments in covert visual search performance, characterized mainly by an increase in the mean reaction time (RT necessary to detect a contralesional target. Only subtle differences were observed between the inactivation effects in both areas. In particular, the magnitude of the deficit was dependant of search task difficulty for LIP, but not for FEF.In the present study, we re-examine these data in order to try to dissociate the specific involvement of these two regions, by considering the entire RT distribution instead of mean RT. We use the LATER model to help us interpret the effects of the inactivations with regard to information accumulation rate and decision processes. We show that: 1 different search strategies can be used by monkeys to perform visual search, either by processing the visual scene in parallel, or by combining parallel and serial processes; 2 LIP and FEF inactivations have very different effects on the RT distributions in the two monkeys. Although our results are not conclusive with regards to the exact functional mechanisms affected by the inactivations, the effects we observe on RT distributions could be accounted by an involvement of LIP in saliency representation or decision-making, and an involvement of FEF in attentional shifts and perception. Finally, we observe that the use of the LATER model is limited in the context of a visual search as it cannot fit all the behavioural strategies encountered. We propose that the diversity in search strategies observed in our monkeys also exists in individual human subjects and should be considered in future

  1. Electroencephalographic abnormalities in antisocial personality disorder.

    Science.gov (United States)

    Calzada-Reyes, Ana; Alvarez-Amador, Alfredo; Galán-García, Lídice; Valdés-Sosa, Mitchell

    2012-01-01

    The presence of brain dysfunction in violent offenders has been frequently examined with inconsistent results. The aim of the study was to assess the EEG of 84 violent offenders by visual inspection and frequency-domain quantitative analysis in 84 violent prisoners. Low-resolution electromagnetic tomography (LORETA) was also employed for theta band of the EEG spectra. Antisocial personality disorder (ASPD) was present in 50 of the offenders and it was absent in the remaining 34. The prevalence of EEG abnormalities, by visual inspection, was similar for both the ASPD group (82%) and non-ASPD group (79%). The brain topography of these anomalies also did not differ between groups, in contrast to results of the EEG quantitative analysis (QEEG) and LORETA that showed remarkable regional differences between both groups. QEEG analysis showed a pattern of excess of theta-delta activities and decrease of alpha band on the right fronto-temporal and left temporo-parietal regions in the ASPD group. LORETA signified an increase of theta activity (5.08 Hz) in ASPD group relative to non-ASPD group within left temporal and parietal regions. Findings indicate that QEEG analysis and techniques of source localization may reveal differences in brain electrical activity among offenders with ASPD, which was not obvious to visual inspection. Copyright © 2011 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  2. Effects of marijuana use on prefrontal and parietal volumes and cognition in emerging adults.

    Science.gov (United States)

    Price, Jenessa S; McQueeny, Tim; Shollenbarger, Skyler; Browning, Erin L; Wieser, Jon; Lisdahl, Krista M

    2015-08-01

    Chronic marijuana (MJ) use among adolescents has been associated with structural and functional abnormalities, particularly in developing regions responsible for higher order cognition. This study investigated prefrontal (PFC) and parietal volumes and executive function in emerging adult MJ users and explored potential gender differences. Participants (ages 18-25) were 27 MJ users and 32 controls without neurologic or psychiatric disorders or heavy other drug use. A series of multiple regressions examined whether group status, past year MJ use, and their interactions with gender predicted ROI volumes. Post hoc analyses consisted of brain-behavior correlations between volumes and cognitive variables and Fisher's z tests to assess group differences. MJ users demonstrated significantly smaller medial orbitofrontal (mOFC; p = 0.004, FDR p = 0.024) and inferior parietal volumes (p = 0.04, FDR p = 0.12); follow-up regressions found that increased past year MJ use did not significantly dose-dependently predict smaller mOFC volume in a sub-sample of individuals with at least one past year MJ use. There were no significant gender interactions. There was a significant brain-behavior difference by group, such that smaller mOFC volumes were associated with poorer complex attention for MJ users (p < 0.05). Smaller mOFC volumes among MJ users suggest disruption of typical neurodevelopmental processes associated with regular MJ use for both genders. These results highlight the need for longitudinal, multi-modal imaging studies providing clearer information on timing of neurodevelopmental processes and neurocognitive impacts of youth MJ initiation.

  3. Functional neuroimaging abnormalities in idiopathic generalized epilepsy

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    Megan L. McGill

    2014-01-01

    Full Text Available Magnetic resonance imaging (MRI techniques have been used to quantitatively assess focal and network abnormalities. Idiopathic generalized epilepsy (IGE is characterized by bilateral synchronous spike–wave discharges on electroencephalography (EEG but normal clinical MRI. Dysfunctions involving the neocortex, particularly the prefrontal cortex, and thalamus likely contribute to seizure activity. To identify possible morphometric and functional differences in the brains of IGE patients and normal controls, we employed measures of thalamic volumes, cortical thickness, gray–white blurring, fractional anisotropy (FA measures from diffusion tensor imaging (DTI and fractional amplitude of low frequency fluctuations (fALFF in thalamic subregions from resting state functional MRI. Data from 27 patients with IGE and 27 age- and sex-matched controls showed similar thalamic volumes, cortical thickness and gray–white contrast. There were no differences in FA values on DTI in tracts connecting the thalamus and prefrontal cortex. Functional analysis revealed decreased fALFF in the prefrontal cortex (PFC subregion of the thalamus in patients with IGE. We provide minimum detectable effect sizes for each measure used in the study. Our analysis indicates that fMRI-based methods are more sensitive than quantitative structural techniques for characterizing brain abnormalities in IGE.

  4. Cognitive Control Signals in Posterior Cingulate Cortex

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    Benjamin eHayden

    2010-12-01

    Full Text Available Efficiently shifting between tasks is a central function of cognitive control. The role of the default network—a constellation of areas with high baseline activity that declines during task performance—in cognitive control remains poorly understood. We hypothesized that task switching demands cognitive control to shift the balance of processing towards the external world, and therefore predicted that switching between the two tasks would require suppression of activity of neurons within the CGp. To test this idea, we recorded the activity of single neurons in posterior cingulate cortex (CGp, a central node in the default network, in monkeys performing two interleaved tasks. As predicted, we found that basal levels of neuronal activity were reduced following a switch from one task to another and gradually returned to pre-switch baseline on subsequent trials. We failed to observe these effects in lateral intraparietal cortex (LIP, part of the dorsal fronto-parietal cortical attention network directly connected to CGp. These findings indicate that suppression of neuronal activity in CGp facilitates cognitive control, and suggest that activity in the default network reflects processes that directly compete with control processes elsewhere in the brain..

  5. Fronto-Parietal Brain Responses to Visuotactile Congruence in an Anatomical Reference Frame

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    Jakub Limanowski

    2018-03-01

    Full Text Available Spatially and temporally congruent visuotactile stimulation of a fake hand together with one’s real hand may result in an illusory self-attribution of the fake hand. Although this illusion relies on a representation of the two touched body parts in external space, there is tentative evidence that, for the illusion to occur, the seen and felt touches also need to be congruent in an anatomical reference frame. We used functional magnetic resonance imaging and a somatotopical, virtual reality-based setup to isolate the neuronal basis of such a comparison. Participants’ index or little finger was synchronously touched with the index or little finger of a virtual hand, under congruent or incongruent orientations of the real and virtual hands. The left ventral premotor cortex responded significantly more strongly to visuotactile co-stimulation of the same versus different fingers of the virtual and real hand. Conversely, the left anterior intraparietal sulcus responded significantly more strongly to co-stimulation of different versus same fingers. Both responses were independent of hand orientation congruence and of spatial congruence of the visuotactile stimuli. Our results suggest that fronto-parietal areas previously associated with multisensory processing within peripersonal space and with tactile remapping evaluate the congruence of visuotactile stimulation on the body according to an anatomical reference frame.

  6. Agnosia for mirror stimuli: a new case report with a small parietal lesion.

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    Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Lebas, Axel; Gerardin, Emmanuel; Hannequin, Didier

    2014-11-01

    Only seven cases of agnosia for mirror stimuli have been reported, always with an extensive lesion. We report a new case of an agnosia for mirror stimuli due to a circumscribed lesion. An extensive battery of neuropsychological tests and a new experimental procedure to assess visual object mirror and orientation discrimination were assessed 10 days after the onset of clinical symptoms, and 5 years later. The performances of our patient were compared with those of four healthy control subjects matched for age. This test revealed an agnosia for mirror stimuli. Brain imaging showed a small right occipitoparietal hematoma, encompassing the extrastriate cortex adjoining the inferior parietal lobe. This new case suggests that: (i) agnosia for mirror stimuli can persist for 5 years after onset and (ii) the posterior part of the right intraparietal sulcus could be critical in the cognitive process of mirror stimuli discrimination. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Fronto-Parietal Brain Responses to Visuotactile Congruence in an Anatomical Reference Frame.

    Science.gov (United States)

    Limanowski, Jakub; Blankenburg, Felix

    2018-01-01

    Spatially and temporally congruent visuotactile stimulation of a fake hand together with one's real hand may result in an illusory self-attribution of the fake hand. Although this illusion relies on a representation of the two touched body parts in external space, there is tentative evidence that, for the illusion to occur, the seen and felt touches also need to be congruent in an anatomical reference frame. We used functional magnetic resonance imaging and a somatotopical, virtual reality-based setup to isolate the neuronal basis of such a comparison. Participants' index or little finger was synchronously touched with the index or little finger of a virtual hand, under congruent or incongruent orientations of the real and virtual hands. The left ventral premotor cortex responded significantly more strongly to visuotactile co-stimulation of the same versus different fingers of the virtual and real hand. Conversely, the left anterior intraparietal sulcus responded significantly more strongly to co-stimulation of different versus same fingers. Both responses were independent of hand orientation congruence and of spatial congruence of the visuotactile stimuli. Our results suggest that fronto-parietal areas previously associated with multisensory processing within peripersonal space and with tactile remapping evaluate the congruence of visuotactile stimulation on the body according to an anatomical reference frame.

  8. Prospective relations between resting-state connectivity of parietal subdivisions and arithmetic competence.

    Science.gov (United States)

    Price, Gavin R; Yeo, Darren J; Wilkey, Eric D; Cutting, Laurie E

    2018-04-01

    The present study investigates the relation between resting-state functional connectivity (rsFC) of cytoarchitectonically defined subdivisions of the parietal cortex at the end of 1st grade and arithmetic performance at the end of 2nd grade. Results revealed a dissociable pattern of relations between rsFC and arithmetic competence among subdivisions of intraparietal sulcus (IPS) and angular gyrus (AG). rsFC between right hemisphere IPS subdivisions and contralateral IPS subdivisions positively correlated with arithmetic competence. In contrast, rsFC between the left hIP1 and the right medial temporal lobe, and rsFC between the left AG and left superior frontal gyrus, were negatively correlated with arithmetic competence. These results suggest that strong inter-hemispheric IPS connectivity is important for math development, reflecting either neurocognitive mechanisms specific to arithmetic processing, domain-general mechanisms that are particularly relevant to arithmetic competence, or structural 'cortical maturity'. Stronger connectivity between IPS, and AG, subdivisions and frontal and temporal cortices, however, appears to be negatively associated with math development, possibly reflecting the ability to disengage suboptimal problem-solving strategies during mathematical processing, or to flexibly reorient task-based networks. Importantly, the reported results pertain even when controlling for reading, spatial attention, and working memory, suggesting that the observed rsFC-behavior relations are specific to arithmetic competence. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. The role of the right temporo-parietal junction in social decision-making.

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    Bitsch, Florian; Berger, Philipp; Nagels, Arne; Falkenberg, Irina; Straube, Benjamin

    2018-03-26

    Identifying someone else's noncooperative intentions can prevent exploitation in social interactions. Hence, the inference of another person's mental state might be most pronounced in order to improve social decision-making. Here, we tested the hypothesis that brain regions associated with Theory of Mind (ToM), particularly the right temporo-parietal junction (rTPJ), show higher neural responses when interacting with a selfish person and that the rTPJ-activity as well as cooperative tendencies will change over time. We used functional magnetic resonance imaging (fMRI) and a modified prisoner's dilemma game in which 20 participants interacted with three fictive playing partners who behaved according to stable strategies either competitively, cooperatively or randomly during seven interaction blocks. The rTPJ and the posterior-medial prefrontal cortex showed higher activity during the interaction with a competitive compared with a cooperative playing partner. Only the rTPJ showed a high response during an early interaction phase, which preceded participants increase in defective decisions. Enhanced functional connectivity between the rTPJ and the left hippocampus suggests that social cognition and learning processes co-occur when behavioral adaptation seems beneficial. © 2018 Wiley Periodicals, Inc.

  10. Inconsistent Effects of Parietal α-tACS on Pseudoneglect across Two Experiments: A Failed Internal Replication

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    Domenica Veniero

    2017-06-01

    Full Text Available Transcranial electrical stimulation (tES is being investigated as an experimental and clinical interventional technique in human participants. While promising, important limitations have been identified, including weak effect sizes and high inter- and intra-individual variability of outcomes. Here, we compared two “inhibitory” tES-techniques with supposedly different mechanisms of action as to their effects on performance in a visuospatial attention task, and report on a direct replication attempt. In two experiments, 2 × 20 healthy participants underwent tES in three separate sessions testing different protocols (10 min stimulation each with a montage targeting right parietal cortex (right parietal–left frontal, electrode-sizes: 3cm × 3cm–7 cm × 5 cm, while performing a perceptual line bisection (landmark task. The tES-protocols were compared as to their ability to modulate pseudoneglect (thought to be under right hemispheric control. In experiment 1, sham-tES was compared to transcranial alternating current stimulation at alpha frequency (10 Hz; α-tACS (expected to entrain “inhibitory” alpha oscillations and to cathodal transcranial direct current stimulation (c-tDCS (shown to suppress neuronal spiking activity. In experiment 2, we attempted to replicate the findings of experiment 1, and establish frequency-specificity by adding a 45 Hz-tACS condition to α-tACS and sham. In experiment 1, right parietal α-tACS led to the expected changes in spatial attention bias, namely a rightward shift in subjective midpoint estimation (relative to sham. However, this was not confirmed in experiment 2 and in the complete sample. Right parietal c-tDCS and 45 Hz-tACS had no effect. These results highlight the importance of replication studies, adequate statistical power and optimizing tES-interventions for establishing the robustness and reliability of electrical stimulation effects, and best practice.

  11. Individual Differences in Reasoning and Visuospatial Attention are Associated with Prefrontal and Parietal White Matter Tracts in Healthy Older Adults

    Science.gov (United States)

    Monge, Zachary A.; Greenwood, Pamela M.; Parasuraman, Raja; Strenziok, Maren

    2016-01-01

    Objective Although reasoning and attention are two cognitive processes necessary for ensuring the efficiency of many everyday activities in older adults, the role of white matter integrity in these processes has been little studied. This is an important question due to the role of white matter integrity as a neural substrate of cognitive aging. Here, we sought to examine the white matter tracts subserving reasoning and visuospatial attention in healthy older adults. Method Sixty-one adults aged 60 and older completed a battery of cognitive tests to assess reasoning and visuospatial attention. In addition, diffusion tensor images were collected to assess Fractional Anisotropy (FA) – a measure of white matter integrity. A principle component analysis of the test scores yielded two components: reasoning and visuospatial attention. Whole-brain correlations between FA and the cognitive components were submitted to probabilistic tractography analyses for visualization of cortical targets of tracts. Results For reasoning, bilateral thalamo-anterior prefrontal, anterior corpus callosum, and corpus callosum body tracts interconnecting the superior frontal cortices and right cingulum bundle were found. For visuospatial attention, a right inferior fronto-parietal tract, and bilateral parietal and temporal connections were found. Conclusions We conclude that in older adults, prefrontal cortex white matter tracts and interhemispheric communication are important in higher order cognitive functioning. On the other hand, right-sided fronto-parietal tracts appear to be critical for supporting control of cognitive processes, such as redirecting attention. Researchers may use our results to develop neuroscience-based interventions for older adults targeting brain mechanisms involved in cognitive plasticity. PMID:26986750

  12. Plant abnormality inspection device

    International Nuclear Information System (INIS)

    Takenaka, Toshio.

    1990-01-01

    The present invention concerns a plant abnormality inspection device for conducting remote or automatic patrolling inspection in a plant and, more particularly, relates to such a device as capable of detecting abnormal odors. That is, the device comprises a moving device for moving to a predetermined position in the plant, a plurality of gas sensors for different kind of gases to be inspected mounted thereon, a comparator for comparing the concentration of a gas detected by the gas sensor with the normal gas concentration at the predetermined position and a judging means for judging the absence or presence of abnormality depending on the combination of the result of the comparison and deliverying a signal if the state is abnormal. As a result, a slight amount of gas responsible to odors released upon abnormality of the plant can be detected by a plurality of gas sensors for different kinds gases to rapidly and easily find abnormal portions in the plant. (I.S.)

  13. Sequential inference as a mode of cognition and its correlates in fronto-parietal and hippocampal brain regions.

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    Thomas H B FitzGerald

    2017-05-01

    Full Text Available Normative models of human cognition often appeal to Bayesian filtering, which provides optimal online estimates of unknown or hidden states of the world, based on previous observations. However, in many cases it is necessary to optimise beliefs about sequences of states rather than just the current state. Importantly, Bayesian filtering and sequential inference strategies make different predictions about beliefs and subsequent choices, rendering them behaviourally dissociable. Taking data from a probabilistic reversal task we show that subjects' choices provide strong evidence that they are representing short sequences of states. Between-subject measures of this implicit sequential inference strategy had a neurobiological underpinning and correlated with grey matter density in prefrontal and parietal cortex, as well as the hippocampus. Our findings provide, to our knowledge, the first evidence for sequential inference in human cognition, and by exploiting between-subject variation in this measure we provide pointers to its neuronal substrates.

  14. Williams Syndrome Hypersociability: A Neuropsychological Study of the Amygdala and Prefrontal Cortex Hypotheses

    Science.gov (United States)

    Capitao, Liliana; Sampaio, Adriana; Fernandez, Montse; Sousa, Nuno; Pinheiro, Ana; Goncalves, Oscar F.

    2011-01-01

    Individuals with Williams syndrome display indiscriminate approach towards strangers. Neuroimaging studies conducted so far have linked this social profile to structural and/or functional abnormalities in WS amygdala and prefrontal cortex. In this study, the neuropsychological hypotheses of amygdala and prefrontal cortex involvement in WS…

  15. Syndecan-1 in the mouse parietal peritoneum microcirculation in inflammation.

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    Paulina M Kowalewska

    Full Text Available BACKGROUND: The heparan sulfate proteoglycan syndecan-1 (CD138 was shown to regulate inflammatory responses by binding chemokines and cytokines and interacting with adhesion molecules, thereby modulating leukocyte trafficking to tissues. The objectives of this study were to examine the expression of syndecan-1 and its role in leukocyte recruitment and chemokine presentation in the microcirculation underlying the parietal peritoneum. METHODS: Wild-type BALB/c and syndecan-1 null mice were stimulated with an intraperitoneal injection of Staphylococcus aureus LTA, Escherichia coli LPS or TNFα and the microcirculation of the parietal peritoneum was examined by intravital microscopy after 4 hours. Fluorescence confocal microscopy was used to examine syndecan-1 expression in the peritoneal microcirculation using fluorescent antibodies. Blocking antibodies to adhesion molecules were used to examine the role of these molecules in leukocyte-endothelial cell interactions in response to LTA. To determine whether syndecan-1 co-localizes with chemokines in vivo, fluorescent antibodies to syndecan-1 were co-injected intravenously with anti-MIP-2 (CXCL2, anti-KC (CXCL1 or anti-MCP-1 (CCL2. RESULTS AND CONCLUSION: Syndecan-1 was localized to the subendothelial region of peritoneal venules and the mesothelial layer. Leukocyte rolling was significantly decreased with LPS treatment while LTA and TNFα significantly increased leukocyte adhesion compared with saline control. Leukocyte-endothelial cell interactions were not different in syndecan-1 null mice. Antibody blockade of β2 integrin (CD18, ICAM-1 (CD54 and VCAM-1 (CD106 did not decrease leukocyte adhesion in response to LTA challenge while blockade of P-selectin (CD62P abrogated leukocyte rolling. Lastly, MIP-2 expression in the peritoneal venules was not dependent on syndecan-1 in vivo. Our data suggest that syndecan-1 is expressed in the parietal peritoneum microvasculature but does not regulate leukocyte

  16. Distinct antigenic characteristics of murine parietal yolk sac laminin

    DEFF Research Database (Denmark)

    Wewer, U M; Tichy, D; Damjanov, A

    1987-01-01

    Two monoclonal antibodies (LAM-A and LAM-B) specific for laminin from normal and neoplastic parietal yolk sac (PYS) cells were produced in rats immunized with a mouse yolk sac carcinoma cell line. Both antibodies immunoprecipitated the 400,000- and 200,000-Da chains of laminin and reacted...... with purified PYS laminin in ELISA. LAM-A reacted with mouse and rat PYS laminin, whereas LAM-B reacted only with mouse PYS laminin. Formaldehyde- and methanol-fixed adult and fetal somatic tissues were immunohistochemically unreactive with either of the two antibodies. In acetone-fixed tissue sections, both...

  17. Laminar thickness alterations in the fronto-parietal cortical mantle of patients with attention-deficit/hyperactivity disorder.

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    Elseline Hoekzema

    Full Text Available Although Attention-Deficit/Hyperactivity Disorder (ADHD was initially regarded as a disorder exclusive to childhood, nowadays its prevalence in adulthood is well established. The development of novel techniques for quantifying the thickness of the cerebral mantle allows the further exploration of the neuroanatomical profiles underlying the child and adult form of the disorder. To examine the cortical mantle in children and adults with ADHD, we applied a vertex-wise analysis of cortical thickness to anatomical brain MRI scans acquired from children with (n = 43 and without ADHD (n = 41, as well as a group of adult neurotypical individuals (n = 31, adult patients with a history of stimulant treatment (n = 31 and medication-naïve adults with ADHD (n = 24. We observed several clusters of reduced laminar cortical thickness in ADHD patients in comparison to neurotypical individuals. These differences were primarily located in the dorsal attention network, including the bilateral inferior and superior parietal cortex and a section of the frontal cortex (centered on the superior frontal and precentral gyrus bilaterally. Further laminar thickness deficits were observed in the bilateral orbitofrontal cortex and medial occipital cortex. The deficits in the cortical surface were especially pronounced in the child sample, while adult patients showed a more typical laminar thickness across the cerebral mantle. These findings show that the neuroanatomical profile of ADHD, especially the childhood form of the disorder, involves robust alterations in the cortical mantle, which are most prominent in brain regions subserving attentional processing.

  18. Altered intrinsic connectivity of the auditory cortex in congenital amusia.

    Science.gov (United States)

    Leveque, Yohana; Fauvel, Baptiste; Groussard, Mathilde; Caclin, Anne; Albouy, Philippe; Platel, Hervé; Tillmann, Barbara

    2016-07-01

    Congenital amusia, a neurodevelopmental disorder of music perception and production, has been associated with abnormal anatomical and functional connectivity in a right frontotemporal pathway. To investigate whether spontaneous connectivity in brain networks involving the auditory cortex is altered in the amusic brain, we ran a seed-based connectivity analysis, contrasting at-rest functional MRI data of amusic and matched control participants. Our results reveal reduced frontotemporal connectivity in amusia during resting state, as well as an overconnectivity between the auditory cortex and the default mode network (DMN). The findings suggest that the auditory cortex is intrinsically more engaged toward internal processes and less available to external stimuli in amusics compared with controls. Beyond amusia, our findings provide new evidence for the link between cognitive deficits in pathology and abnormalities in the connectivity between sensory areas and the DMN at rest. Copyright © 2016 the American Physiological Society.

  19. Defining Abnormally Low Tenders

    DEFF Research Database (Denmark)

    Ølykke, Grith Skovgaard; Nyström, Johan

    2017-01-01

    The concept of an abnormally low tender is not defined in EU public procurement law. This article takes an interdisciplinary law and economics approach to examine a dataset consisting of Swedish and Danish judgments and verdicts concerning the concept of an abnormally low tender. The purpose...

  20. The role of prefrontal cortex in psychopathy

    Science.gov (United States)

    Koenigs, Michael

    2014-01-01

    Psychopathy is a personality disorder characterized by remorseless and impulsive antisocial behavior. Given the significant societal costs of the recidivistic criminal activity associated with the disorder, there is a pressing need for more effective treatment strategies, and hence, a better understanding of the psychobiological mechanisms underlying the disorder. The prefrontal cortex (PFC) is likely to play an important role in psychopathy. In particular, the ventromedial and anterior cingulate sectors of PFC are theorized to mediate a number of social and affective decision-making functions that appear to be disrupted in psychopathy. This article provides a critical summary of human neuroimaging data implicating prefrontal dysfunction in psychopathy. A growing body of evidence associates psychopathy with structural and functional abnormalities in ventromedial PFC and anterior cingulate cortex. Although this burgeoning field still faces a number of methodological challenges and outstanding questions that will need to be resolved by future studies, the research to date has established a link between psychopathy and PFC. PMID:22752782

  1. Excitatory Neuronal Hubs Configure Multisensory Integration of Slow Waves in Association Cortex

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    Satoshi Kuroki

    2018-03-01

    Full Text Available Summary: Multisensory integration (MSI is a fundamental emergent property of the mammalian brain. During MSI, perceptual information encoded in patterned activity is processed in multimodal association cortex. The systems-level neuronal dynamics that coordinate MSI, however, are unknown. Here, we demonstrate intrinsic hub-like network activity in the association cortex that regulates MSI. We engineered calcium reporter mouse lines based on the fluorescence resonance energy transfer sensor yellow cameleon (YC2.60 expressed in excitatory or inhibitory neurons. In medial and parietal association cortex, we observed spontaneous slow waves that self-organized into hubs defined by long-range excitatory and local inhibitory circuits. Unlike directional source/sink-like flows in sensory areas, medial/parietal excitatory and inhibitory hubs had net-zero balanced inputs. Remarkably, multisensory stimulation triggered rapid phase-locking mainly of excitatory hub activity persisting for seconds after the stimulus offset. Therefore, association cortex tends to form balanced excitatory networks that configure slow-wave phase-locking for MSI. Video Abstract: : Kuroki et al. performed cell-type-specific, wide-field FRET-based calcium imaging to visualize cortical network activity induced by multisensory inputs. They observed phase-locking of cortical slow waves in excitatory neuronal hubs in association cortical areas that may underlie multisensory integration. Keywords: wide-field calcium imaging, multisensory integration, cortical slow waves, association cortex, phase locking, fluorescence resonance energy transfer, spontaneous activity, excitatory neuron, inhibitory neuron, mouse

  2. Abnormal Ventral and Dorsal Attention Network Activity During Single and Dual Target Detection in Schizophrenia

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    Amy M. Jimenez

    2016-03-01

    Full Text Available Early visual perception and attention are impaired in schizophrenia, and these deficits can be observed on target detection tasks. These tasks activate distinct ventral and dorsal brain networks which support stimulus-driven and goal-directed attention, respectively. We used single and dual target rapid serial visual presentation (RSVP tasks during fMRI with an ROI approach to examine regions within these networks associated with target detection and the attentional blink (AB in 21 schizophrenia outpatients and 25 healthy controls. In both tasks, letters were targets and numbers were distractors. For the dual target task, the second target (T2 was presented at 3 different lags after the first target (T1 (lag1=100ms, lag3=300ms, lag7=700ms. For both single and dual target tasks, patients identified fewer targets than controls. For the dual target task, both groups showed the expected AB effect with poorer performance at lag 3 than at lags 1 or 7, and there was no group by lag interaction. During the single target task, patients showed abnormally increased deactivation of the temporo-parietal junction (TPJ, a key region of the ventral network. When attention demands were increased during the dual target task, patients showed overactivation of the posterior intraparietal cortex, a key dorsal network region, along with failure to deactivate TPJ. Results suggest inefficient and faulty suppression of salience-oriented processing regions, resulting in increased sensitivity to stimuli in general, and difficulty distinguishing targets from non-targets.

  3. Boosting Memory by tDCS to Frontal or Parietal Brain Regions? A Study of the Enactment Effect Shows No Effects for Immediate and Delayed Recognition

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    Beat Meier

    2018-06-01

    Full Text Available Boosting memory with transcranial direct current stimulation (tDCS seems to be an elegant way to optimize learning. Here we tested whether tDCS to the left dorsolateral prefrontal cortex or to the left posterior parietal cortex would boost recognition memory in general and/or particularly for action phrases enacted at study. During study, 48 young adults either read or enacted simple action phrases. Memory for the action phrases was assessed after a retention interval of 45 min and again after 7-days to investigate the long-term consequences of brain stimulation. The results showed a robust enactment effect in both test sessions. Moreover, the decrease in performance was more pronounced for reading than for enacting the phrases at study. However, tDCS did not reveal any effect on subsequent recognition memory performance. We conclude that memory benefits of tDCS are not easily replicated. In contrast, enactment at study reliably boosts subsequent memory.

  4. Reduced dorso-lateral prefrontal cortex in treatment resistant schizophrenia.

    Science.gov (United States)

    Zugman, André; Gadelha, Ary; Assunção, Idaiane; Sato, João; Ota, Vanessa K; Rocha, Deyvis L; Mari, Jair J; Belangero, Sintia I; Bressan, Rodrigo A; Brietzke, Elisa; Jackowski, Andrea P

    2013-08-01

    Treatment resistance affects up to one third of patients with schizophrenia (SCZ). A better understanding of its biological underlying processes could improve treatment. The aim of this study was to compare cortical thickness between non-resistant SCZ (NR-SCZ), treatment-resistant SCZ (TR-SCZ) patients and healthy controls (HC). Structural MRI scans were obtained from 3 groups of individuals: 61 treatment resistant SCZ individuals, 67 non-resistant SCZ and 80 healthy controls. Images were analyzed using cortical surface modelling (implemented in freesurfer package) to identify group differences in cortical thickness. Statistical significant differences were identified using Monte-Carlo simulation method with a corrected p-cluster<0.01. Patients in the TR-SCZ group showed a widespread reduction in cortical thickness in frontal, parietal, temporal and occipital regions bilaterally. NR-SCZ group had reduced cortex in two regions (left superior frontal cortex and left caudal middle frontal cortex). TR-SCZ group also showed decreased thickness in the left dorsolateral prefrontal cortex (DLPFC) when compared with patients from NR-SCZ group. The reduction in cortical thickness in DLPFC indicates a more severe form of the disease or a specific finding for this group. Alterations in this region should be explored as a putative marker for treatment resistance. Prospective studies, with individuals being followed from first episode psychosis until refractoriness is diagnosed, are needed to clarify these hypotheses. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Prefrontal and parietal correlates of cognitive control related to the adult outcome of attention-deficit/hyperactivity disorder diagnosed in childhood.

    Science.gov (United States)

    Schulz, Kurt P; Li, Xiaobo; Clerkin, Suzanne M; Fan, Jin; Berwid, Olga G; Newcorn, Jeffrey H; Halperin, Jeffrey M

    2017-05-01

    The protracted and highly variable development of prefrontal cortex regions that support cognitive control has been purported to shape the adult outcome of attention-deficit/hyperactivity disorder (ADHD). This neurodevelopmental model was tested in a prospectively followed sample of 27 adult probands who were diagnosed with ADHD in childhood and 28 carefully matched comparison subjects aged 21-28 years. Probands were classified with persistent ADHD or remitted ADHD. Behavioral and neural responses to the Stimulus and Response Conflict Task (SRCT) performed during functional magnetic resonance imaging (fMRI) were compared in probands and comparison subjects and in probands with persistent and remitted ADHD. Response speed and accuracy for stimulus, response, and combined conflicts did not differ across groups. Orbitofrontal, inferior frontal and parietal activation was lower in probands than comparison subjects, but only for combined conflicts, when demand for cognitive control was highest. Reduced activation for combined conflicts in probands was almost wholly attributable to the persistence of ADHD; orbitofrontal, inferior frontal, anterior cingulate and parietal activation was lower in probands with persistent ADHD than both probands with remitted ADHD and comparison subjects, but did not differ between probands with remitted ADHD and comparison subjects. These data provide the first evidence that prefrontal and parietal activation during cognitive control parallels the adult outcome of ADHD diagnosed in childhood, with persistence of symptoms linked to reduced activation and symptom recovery associated with activation indistinguishable from adults with no history of ADHD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Laparoscopic adrenal cortex

    International Nuclear Information System (INIS)

    Peyrolou, A.; Salom, A.; Harguindeguy; Taroco, L.; Ardao, G.; Broli, F. . E mail: andresssss@adinet.com.uy

    2005-01-01

    The paper presents the case of a female patient who carried an aldosterone-secreting tumor of adrenal cortex.In the analysis of diagnosis and para clinical examinations there is particular reference to the laparoscopic surgery mode of treatment.Diagnosis should be established on the basis of clinical and laboratory tests (hypopotassemia and hyperaldosteronism).Tumor topography was confirmed through CT scan, MRI and Scintiscan in left adrenal cortex.Resection was consequently made through laparoscopic surgery.The patients evolution was excellent from the surgical viewpoint,with I levels of blood pressure, potassium and aldosterone returned to normal

  7. Task context impacts visual object processing differentially across the cortex

    Science.gov (United States)

    Harel, Assaf; Kravitz, Dwight J.; Baker, Chris I.

    2014-01-01

    Perception reflects an integration of “bottom-up” (sensory-driven) and “top-down” (internally generated) signals. Although models of visual processing often emphasize the central role of feed-forward hierarchical processing, less is known about the impact of top-down signals on complex visual representations. Here, we investigated whether and how the observer’s goals modulate object processing across the cortex. We examined responses elicited by a diverse set of objects under six distinct tasks, focusing on either physical (e.g., color) or conceptual properties (e.g., man-made). Critically, the same stimuli were presented in all tasks, allowing us to investigate how task impacts the neural representations of identical visual input. We found that task has an extensive and differential impact on object processing across the cortex. First, we found task-dependent representations in the ventral temporal and prefrontal cortex. In particular, although object identity could be decoded from the multivoxel response within task, there was a significant reduction in decoding across tasks. In contrast, the early visual cortex evidenced equivalent decoding within and across tasks, indicating task-independent representations. Second, task information was pervasive and present from the earliest stages of object processing. However, although the responses of the ventral temporal, prefrontal, and parietal cortex enabled decoding of both the type of task (physical/conceptual) and the specific task (e.g., color), the early visual cortex was not sensitive to type of task and could only be used to decode individual physical tasks. Thus, object processing is highly influenced by the behavioral goal of the observer, highlighting how top-down signals constrain and inform the formation of visual representations. PMID:24567402

  8. Chromosomal abnormalities and autism

    Directory of Open Access Journals (Sweden)

    Farida El-Baz

    2016-01-01

    Conclusion: Chromosomal abnormalities were not detected in the studied autistic children, and so the relation between the genetics and autism still needs further work up with different study methods and techniques.

  9. Chromosomal Abnormalities in ADHD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2002-07-01

    Full Text Available The prevalence of fragile X syndrome, velocardiofacial syndrome (VCFS, and other cytogenetic abnormalities among 100 children (64 boys with combined type ADHD and normal intelligence was assessed at the NIMH and Georgetown University Medical Center.

  10. "Jeopardy" in Abnormal Psychology.

    Science.gov (United States)

    Keutzer, Carolin S.

    1993-01-01

    Describes the use of the board game, Jeopardy, in a college level abnormal psychology course. Finds increased student interaction and improved application of information. Reports generally favorable student evaluation of the technique. (CFR)

  11. Abnormal Uterine Bleeding

    Science.gov (United States)

    ... especially the progestin-only pill (also called the “mini-pill”) can actually cause abnormal bleeding for some ... Basics Sports Safety Injury Rehabilitation Emotional Well-Being Mental Health Sex and Birth Control Sex and Sexuality ...

  12. Interleukin-17A Promotes Parietal Cell Atrophy by Inducing ApoptosisSummary

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    Kevin A. Bockerstett

    Full Text Available Background & Aims: Atrophic gastritis caused by chronic inflammation in the gastric mucosa leads to the loss of gastric glandular cells, including acid-secreting parietal cells. Parietal cell atrophy in a setting of chronic inflammation induces spasmolytic polypeptide expressing metaplasia, a critical step in gastric carcinogenesis. However, the mechanisms by which inflammation causes parietal cell atrophy and spasmolytic polypeptide expressing metaplasia are not well defined. We investigated the role of interleukin-17A (IL-17A in causing parietal cell atrophy. Methods: A mouse model of autoimmune atrophic gastritis was used to examine IL-17A production during early and late stages of disease. Organoids derived from corpus glands were used to determine the direct effects of IL-17A on gastric epithelial cells. Immunofluorescent staining was used to examine IL-17A receptors and the direct effect of signaling on parietal cells. Mice were infected with an IL-17A-producing adenovirus to determine the effects of IL-17A on parietal cells in vivo. Finally, IL-17A neutralizing antibodies were administered to mice with active atrophic gastritis to evaluate the effects on parietal cell atrophy and metaplasia. Results: Increased IL-17A correlated with disease severity in mice with chronic atrophic gastritis. IL-17A caused caspase-dependent gastric organoid degeneration, which could not be rescued with a necroptosis inhibitor. Parietal cells expressed IL-17A receptors and IL-17A treatment induced apoptosis in parietal cells. Overexpressing IL-17A in vivo induced caspase-3 activation and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling staining in parietal cells. Finally, IL-17A neutralizing antibody decreased parietal cell atrophy and metaplasia in mice with chronic atrophic gastritis. Conclusions: These data identify IL-17A as a cytokine that promotes parietal cell apoptosis during atrophic gastritis, a

  13. An impaired attentional dwell time after parietal and frontal lesions related to impaired selective attention not unilateral neglect.

    Science.gov (United States)

    Correani, Alessia; Humphreys, Glyn W

    2011-07-01

    The attentional blink, a measure of the temporal dynamics of visual processing, has been documented to be more pronounced following brain lesions that are associated with visual neglect. This suggests that, in addition to their spatial bias in attention, neglect patients may have a prolonged dwell time for attention. Here the attentional dwell time was examined in patients with damage focused on either posterior parietal or frontal cortices. In three experiments, we show that there is an abnormally pronounced attentional dwell time, which does not differ in patients with posterior parietal and with frontal lobe lesions, and this is associated with a measure of selective attention but not with measures of spatial bias in selection. These data occurred both when we attempted to match patients and controls for overall differences in performance and when a single set stimulus exposure was used across participants. In Experiments 1 and 2, requiring report of colour-form conjunctions, there was evidence that the patients were also impaired at temporal binding, showing errors in feature combination across stimuli and in reporting in the correct temporal order. In Experiment 3, requiring only the report of features but introducing task switching led to similar results. The data suggest that damage to a frontoparietal network can compromise temporal selection of visual stimuli; however, this is not necessarily related to a deficit in hemispatial visual attention but it is to impaired target selection. We discuss the implications for understanding visual selection.

  14. Abnormal sound detection device

    International Nuclear Information System (INIS)

    Yamada, Izumi; Matsui, Yuji.

    1995-01-01

    Only components synchronized with rotation of pumps are sampled from detected acoustic sounds, to judge the presence or absence of abnormality based on the magnitude of the synchronized components. A synchronized component sampling means can remove resonance sounds and other acoustic sounds generated at a synchronously with the rotation based on the knowledge that generated acoustic components in a normal state are a sort of resonance sounds and are not precisely synchronized with the number of rotation. On the other hand, abnormal sounds of a rotating body are often caused by compulsory force accompanying the rotation as a generation source, and the abnormal sounds can be detected by extracting only the rotation-synchronized components. Since components of normal acoustic sounds generated at present are discriminated from the detected sounds, reduction of the abnormal sounds due to a signal processing can be avoided and, as a result, abnormal sound detection sensitivity can be improved. Further, since it is adapted to discriminate the occurrence of the abnormal sound from the actually detected sounds, the other frequency components which are forecast but not generated actually are not removed, so that it is further effective for the improvement of detection sensitivity. (N.H.)

  15. The Role of Medial Frontal Cortex in Action Anticipation in Professional Badminton Players.

    Science.gov (United States)

    Xu, Huan; Wang, Pin; Ye, Zhuo'er; Di, Xin; Xu, Guiping; Mo, Lei; Lin, Huiyan; Rao, Hengyi; Jin, Hua

    2016-01-01

    , right inferior parietal lobule, left insula and particularly, and left medial frontal cortex.

  16. The Role of Medial Frontal Cortex in Action Anticipation in Professional Badminton Players

    Science.gov (United States)

    Xu, Huan; Wang, Pin; Ye, Zhuo’er; Di, Xin; Xu, Guiping; Mo, Lei; Lin, Huiyan; Rao, Hengyi; Jin, Hua

    2016-01-01

    , right inferior parietal lobule, left insula and particularly, and left medial frontal cortex. PMID:27909422

  17. Projections to early visual areas V1 and V2 in the calcarine fissure from parietal association areas in the macaque.

    Directory of Open Access Journals (Sweden)

    Elena eBorra

    2011-06-01

    Full Text Available Non-extrastriate projections to area V1 in monkeys, now demonstrated by several anatomical studies, are potential substrates of physiologically documented multisensory effects in primary sensory areas. The full network of projections among association and primary areas, however, is likely to be complex and is still only partially understood. In the present report, we used the anterograde tracer biotinylated dextran amine to investigate projections to areas V1 and V2 from subdivisions of the parietal association cortex in macaque. Parietal cortex was chosen to allow comparisons between projections from this higher association area and from other previously reported areas. In addition, we were interested in further elucidating pathways to areas V1 and V2 from parietal areas, as potentially contributing to attention and active vision. Of eight cases, three brains had projections only to area V2, and the five others projected to both areas V1 and V2. Terminations in area V1 were sparse. These were located in supragranular layers I, II, upper III; occasionally in IVB; and in layer VI. Terminations in V2 were denser, and slightly more prevalent in the supragranular layers. For both areas, terminations were in the calcarine region, corresponding to the representation of the peripheral visual field. By reconstructions of single axons, we demonstrated that four of nine axons had collaterals, either to V1 and V2 (n=1 or to area V1 and a ventral area likely to be TEO (n=3. In area V1, axons extended divergently in layer VI as well as layer I. Overall, these and previous results suggest a nested connectivity architecture, consisting of multiple direct and indirect recurrent projections from association areas to area V1. Terminations in area V1 are not abundant, but could be potentiated by the network of indirect connections.

  18. The impact of auditory working memory training on the fronto-parietal working memory network.

    Science.gov (United States)

    Schneiders, Julia A; Opitz, Bertram; Tang, Huijun; Deng, Yuan; Xie, Chaoxiang; Li, Hong; Mecklinger, Axel

    2012-01-01

    Working memory training has been widely used to investigate working memory processes. We have shown previously that visual working memory benefits only from intra-modal visual but not from across-modal auditory working memory training. In the present functional magnetic resonance imaging study we examined whether auditory working memory processes can also be trained specifically and which training-induced activation changes accompany theses effects. It was investigated whether working memory training with strongly distinct auditory materials transfers exclusively to an auditory (intra-modal) working memory task or whether it generalizes to a (across-modal) visual working memory task. We used adaptive n-back training with tonal sequences and a passive control condition. The memory training led to a reliable training gain. Transfer effects were found for the (intra-modal) auditory but not for the (across-modal) visual transfer task. Training-induced activation decreases in the auditory transfer task were found in two regions in the right inferior frontal gyrus. These effects confirm our previous findings in the visual modality and extents intra-modal effects in the prefrontal cortex to the auditory modality. As the right inferior frontal gyrus is frequently found in maintaining modality-specific auditory information, these results might reflect increased neural efficiency in auditory working memory processes. Furthermore, task-unspecific (amodal) activation decreases in the visual and auditory transfer task were found in the right inferior parietal lobule and the superior portion of the right middle frontal gyrus reflecting less demand on general attentional control processes. These data are in good agreement with amodal activation decreases within the same brain regions on a visual transfer task reported previously.

  19. Lower Parietal Encoding Activation Is Associated with Sharper Information and Better Memory.

    Science.gov (United States)

    Lee, Hongmi; Chun, Marvin M; Kuhl, Brice A

    2017-04-01

    Mean fMRI activation in ventral posterior parietal cortex (vPPC) during memory encoding often negatively predicts successful remembering. A popular interpretation of this phenomenon is that vPPC reflects "off-task" processing. However, recent fMRI studies considering distributed patterns of activity suggest that vPPC actively represents encoded material. Here, we assessed the relationships between pattern-based content representations in vPPC, mean activation in vPPC, and subsequent remembering. We analyzed data from two fMRI experiments where subjects studied then recalled word-face or word-scene associations. For each encoding trial, we measured 1) mean univariate activation within vPPC and 2) the strength of face/scene information as indexed by pattern analysis. Mean activation in vPPC negatively predicted subsequent remembering, but the strength of pattern-based information in the same vPPC voxels positively predicted later memory. Indeed, univariate amplitude averaged across vPPC voxels negatively correlated with pattern-based information strength. This dissociation reflected a tendency for univariate reductions to maximally occur in voxels that were not strongly tuned for the category of encoded stimuli. These results indicate that vPPC activity patterns reflect the content and quality of memory encoding and constitute a striking example of lower univariate activity corresponding to stronger pattern-based information. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. The impact of auditory working memory training on the fronto-parietal working memory network

    Science.gov (United States)

    Schneiders, Julia A.; Opitz, Bertram; Tang, Huijun; Deng, Yuan; Xie, Chaoxiang; Li, Hong; Mecklinger, Axel

    2012-01-01

    Working memory training has been widely used to investigate working memory processes. We have shown previously that visual working memory benefits only from intra-modal visual but not from across-modal auditory working memory training. In the present functional magnetic resonance imaging study we examined whether auditory working memory processes can also be trained specifically and which training-induced activation changes accompany theses effects. It was investigated whether working memory training with strongly distinct auditory materials transfers exclusively to an auditory (intra-modal) working memory task or whether it generalizes to a (across-modal) visual working memory task. We used adaptive n-back training with tonal sequences and a passive control condition. The memory training led to a reliable training gain. Transfer effects were found for the (intra-modal) auditory but not for the (across-modal) visual transfer task. Training-induced activation decreases in the auditory transfer task were found in two regions in the right inferior frontal gyrus. These effects confirm our previous findings in the visual modality and extents intra-modal effects in the prefrontal cortex to the auditory modality. As the right inferior frontal gyrus is frequently found in maintaining modality-specific auditory information, these results might reflect increased neural efficiency in auditory working memory processes. Furthermore, task-unspecific (amodal) activation decreases in the visual and auditory transfer task were found in the right inferior parietal lobule and the superior portion of the right middle frontal gyrus reflecting less demand on general attentional control processes. These data are in good agreement with amodal activation decreases within the same brain regions on a visual transfer task reported previously. PMID:22701418

  1. Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia.

    Science.gov (United States)

    Iuculano, Teresa; Cohen Kadosh, Roi

    2014-01-01

    Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD), which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small-yet constant-current through the brain, a non-invasive technique named transcranial electrical stimulation (tES). Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS) in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC). The first subject (DD1) received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance's improvements in healthy subjects. The second subject (DD2) received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i) automaticity of number processing; and (ii) mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation, and education.

  2. Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia

    Directory of Open Access Journals (Sweden)

    Teresa eIuculano

    2014-02-01

    Full Text Available Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD, which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small – yet constant – current through the brain, a non-invasive technique named transcranial electrical stimulation (tES. Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC. The first subject (DD1 received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance’s improvements in healthy subjects. The second subject (DD2 received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i automaticity of number processing; and (ii mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation

  3. Low intensity areas observed T2-weighted magnetic resonance imaging of the cerebral cortex in various neurological diseases

    Energy Technology Data Exchange (ETDEWEB)

    Imon, Yukari [Hiroshima Univ. (Japan). School of Medicine

    1996-02-01

    We retrospectively studied magnetic resonance images of the brain in 158 patients (8 cases of amyotrophic lateral sclerosis, 16 cases of Alzheimer`s disease, 8 cases of Parkinson`s disease, 53 cases of multiple cerebral infarct, 20 cases of other central nervous system (CNS) diseases, and 53 cases without any CNS disease) to examine the appearance of T2-weighted low signal intensity areas (LIA) in the cerebral cortex. The age of subjects ranged from 36 to 85 years with the mean 65.0 and SD 9.9 years. LIA in the motor and sensory cortices, and brain atrophy were evaluated visually on axial images of the spin-echo sequence obtained with a 1.5 tesla system. The incidence of LIA in the motor cortex was significantly higher in all CNS diseases than in cases without any CNS disease, but not significantly different among CNS diseases. LIA in the motor cortex showed a correlation with age, temporal and parietal atrophy. The appearance of LIA in the sensory cortex correlated with that of LIA in the motor cortex, and parietal atrophy. These results suggest that LIA may appear according to age and be associated with the accumulation of nonheme iron in the cortex, especially in patients with CNS diseases. (author)

  4. Developmental specialization of the left parietal cortex for the semantic representation of Arabic numerals: An fMR-adaptation study

    Directory of Open Access Journals (Sweden)

    Stephan E. Vogel

    2015-04-01

    Full Text Available The way the human brain constructs representations of numerical symbols is poorly understood. While increasing evidence from neuroimaging studies has indicated that the intraparietal sulcus (IPS becomes increasingly specialized for symbolic numerical magnitude representation over developmental time, the extent to which these changes are associated with age-related differences in symbolic numerical magnitude representation or with developmental changes in non-numerical processes, such as response selection, remains to be uncovered. To address these outstanding questions we investigated developmental changes in the cortical representation of symbolic numerical magnitude in 6- to 14-year-old children using a passive functional magnetic resonance imaging adaptation design, thereby mitigating the influence of response selection. A single-digit Arabic numeral was repeatedly presented on a computer screen and interspersed with the presentation of novel digits deviating as a function of numerical ratio (smaller/larger number. Results demonstrated a correlation between age and numerical ratio in the left IPS, suggesting an age-related increase in the extent to which numerical symbols are represented in the left IPS. Brain activation of the right IPS was modulated by numerical ratio but did not correlate with age, indicating hemispheric differences in IPS engagement during the development of symbolic numerical representation.

  5. Number-space interactions in the human parietal cortex: Enlightening the SNARC effect with functional near-infrared spectroscopy.

    Science.gov (United States)

    Cutini, Simone; Scarpa, Fabio; Scatturin, Pietro; Dell'Acqua, Roberto; Zorzi, Marco

    2014-02-01

    Interactions between numbers and space have become a major issue in cognitive neuroscience, because they suggest that numerical representations might be deeply rooted in cortical networks that also subserve spatial cognition. The spatial-numerical association of response codes (SNARC) is the most robust and widely replicated demonstration of the link between numbers and space: in magnitude comparison or parity judgments, participants' reaction times to small numbers are faster with left than right effectors, whereas the converse is found for large numbers. However, despite the massive body of research on number-space interactions, the nature of the SNARC effect remains controversial and no study to date has identified its hemodynamic correlates. Using functional near-infrared spectroscopy, we found a hemodynamic signature of the SNARC effect in the bilateral intraparietal sulcus, a core region for numerical magnitude representation, and left angular gyrus (ANG), a region implicated in verbal number processing. Activation of intraparietal sulcus was also modulated by numerical distance. Our findings point to number semantics as cognitive locus of number-space interactions, thereby revealing the intrinsic spatial nature of numerical magnitude representation. Moreover, the involvement of left ANG is consistent with the mediating role of verbal/cultural factors in shaping interactions between numbers and space.

  6. Lesion of posterior parietal cortex in rats does not disrupt place avoidance based on either distal or proximal orienting cues

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Jan; Telenský, Petr; Blahna, Karel; Zach, P.; Bureš, Jan; Stuchlík, Aleš

    2008-01-01

    Roč. 445, č. 1 (2008), s. 73-77 ISSN 0304-3940 R&D Projects: GA MŠk(CZ) 1M0517; GA ČR(CZ) GA309/07/0341; GA ČR(CZ) GD206/05/H012 Institutional research plan: CEZ:AV0Z50110509 Keywords : learning * memory * rat Subject RIV: FH - Neurology Impact factor: 2.200, year: 2008

  7. Impact of cannabis use on prefrontal and parietal cortex gyrification and surface area in adolescents and emerging adults

    Directory of Open Access Journals (Sweden)

    Skyler G. Shollenbarger

    2015-12-01

    Conclusions: Cannabis use was associated with reduced gyrification in PFC regions implicated in self-referential thought and social cognition. Results suggest that these gyrification characteristics may have cognitive implications.

  8. Orbitofrontal cortex function and structure in depression.

    Science.gov (United States)

    Drevets, Wayne C

    2007-12-01

    The orbitofrontal cortex (OFC) has been implicated in the pathophysiology of major depression by evidence obtained using neuroimaging, neuropathologic, and lesion analysis techniques. The abnormalities revealed by these techniques show a regional specificity, and suggest that some OFC regions which appear cytoarchitectonically distinct also are functionally distinct with respect to mood regulation. For example, the severity of depression correlates inversely with physiological activity in parts of the posterior lateral and medial OFC, consistent with evidence that dysfunction of the OFC associated with cerebrovascular lesions increases the vulnerability for developing the major depressive syndrome. The posterior lateral and medial OFC function may also be impaired in individuals who develop primary mood disorders, as these patients show grey-matter volumetric reductions, histopathologic abnormalities, and altered hemodynamic responses to emotionally valenced stimuli, probabilistic reversal learning, and reward processing. In contrast, physiological activity in the anteromedial OFC situated in the ventromedial frontal polar cortex increases during the depressed versus the remitted phases of major depressive disorder to an extent that is positively correlated with the severity of depression. Effective antidepressant treatment is associated with a reduction in activity in this region. Taken together these data are compatible with evidence from studies in experimental animals indicating that some orbitofrontal and medial prefrontal cortex regions function to inhibit, while others function to enhance, emotional expression. Alterations in the functional balance between these regions and the circuits they form with anatomically related areas of the temporal lobe, striatum, thalamus, and brain stem thus may underlie the pathophysiology of mood disorders, such as major depression.

  9. [Walking abnormalities in children].

    Science.gov (United States)

    Segawa, Masaya

    2010-11-01

    Walking is a spontaneous movement termed locomotion that is promoted by activation of antigravity muscles by serotonergic (5HT) neurons. Development of antigravity activity follows 3 developmental epochs of the sleep-wake (S-W) cycle and is modulated by particular 5HT neurons in each epoch. Activation of antigravity activities occurs in the first epoch (around the age of 3 to 4 months) as restriction of atonia in rapid eye movement (REM) stage and development of circadian S-W cycle. These activities strengthen in the second epoch, with modulation of day-time sleep and induction of crawling around the age of 8 months and induction of walking by 1 year. Around the age of 1 year 6 months, absence of guarded walking and interlimb cordination is observed along with modulation of day-time sleep to once in the afternoon. Bipedal walking in upright position occurs in the third epoch, with development of a biphasic S-W cycle by the age of 4-5 years. Patients with infantile autism (IA), Rett syndrome (RTT), or Tourette syndrome (TS) show failure in the development of the first, second, or third epoch, respectively. Patients with IA fail to develop interlimb coordination; those with RTT, crawling and walking; and those with TS, walking in upright posture. Basic pathophysiology underlying these condition is failure in restricting atonia in REM stage; this induces dysfunction of the pedunculopontine nucleus and consequently dys- or hypofunction of the dopamine (DA) neurons. DA hypofunction in the developing brain, associated with compensatory upward regulation of the DA receptors causes psychobehavioral disorders in infancy (IA), failure in synaptogenesis in the frontal cortex and functional development of the motor and associate cortexes in late infancy through the basal ganglia (RTT), and failure in functional development of the prefrontal cortex through the basal ganglia (TS). Further, locomotion failure in early childhood causes failure in development of functional

  10. Abnormal resting-state functional connectivity study in unilateral pulsatile tinnitus patients with single etiology: A seed-based functional connectivity study

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Han [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Neuroradiology Division, Department of Radiology, Stanford University, CA, 94305 (United States); Zhao, Pengfei [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Liu, Zhaohui [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 (China); Li, Rui; Zhang, Ling; Wang, Peng [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Yan, Fei [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 (China); Liu, Liheng [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Wang, Guopeng; Zeng, Rong [Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Li, Ting [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 (China); Dong, Cheng [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Gong, Shusheng, E-mail: gongss@ccmu.edu.cn [Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Wang, Zhenchang, E-mail: cjr.wzhch@vip.163.com [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China)

    2016-11-15

    Objective: Previous studies demonstrated altered regional neural activations in several brain areas in patients with pulsatile tinnitus (PT), especially indicating an important role of posterior cingulate cortex (PCC). However, few studies focused on the degree of functional connectivity (FC) of this area in PT patients. In this study, we will compare the FC of PCC in patients affected with this condition and normal controls by using resting-state functional magnetic resonance imaging (fMRI). Methods: Structural and functional MRI data were obtained from 36 unilateral PT patients with single etiology and 36 matched healthy controls. FC feature of the region of interest (PCC) were characterized using a seed-based correlation method with the voxels in the whole-brain. Results: Compared with healthy controls, patients showed significant decreased FC to the right middle temporal gyrus (MTG), right thalamus and bilateral insula. By contrast, PCC demonstrated increased functional connectivity between the precuneus, bilateral inferior parietal lobule and middle occipital gyrus. We also found correlations between the disease duration of PT and FC of PCC-right MTG (r = −0.616, p < 0.001). Conclusions: Unilateral PT patients could have abnormal FC to the PCC bilaterally in the brain. PCC, as a highly integrated brain area, is an example of nucleus that was involved in mediation between different neural networks. It might be a modulation core between visual network and auditory network. The decreased FC of MTG to PCC may indicate a down regulation of activity between PCC and auditory associated brain cortex. Decreased FC between limbic system (bilateral AI) and PCC may reflect the emotional message control in patient group. This study facilitated understanding of the underlying neuropathological process in patients with pulsatile tinnitus.

  11. Abnormal resting-state functional connectivity study in unilateral pulsatile tinnitus patients with single etiology: A seed-based functional connectivity study

    International Nuclear Information System (INIS)

    Lv, Han; Zhao, Pengfei; Liu, Zhaohui; Li, Rui; Zhang, Ling; Wang, Peng; Yan, Fei; Liu, Liheng; Wang, Guopeng; Zeng, Rong; Li, Ting; Dong, Cheng; Gong, Shusheng; Wang, Zhenchang

    2016-01-01

    Objective: Previous studies demonstrated altered regional neural activations in several brain areas in patients with pulsatile tinnitus (PT), especially indicating an important role of posterior cingulate cortex (PCC). However, few studies focused on the degree of functional connectivity (FC) of this area in PT patients. In this study, we will compare the FC of PCC in patients affected with this condition and normal controls by using resting-state functional magnetic resonance imaging (fMRI). Methods: Structural and functional MRI data were obtained from 36 unilateral PT patients with single etiology and 36 matched healthy controls. FC feature of the region of interest (PCC) were characterized using a seed-based correlation method with the voxels in the whole-brain. Results: Compared with healthy controls, patients showed significant decreased FC to the right middle temporal gyrus (MTG), right thalamus and bilateral insula. By contrast, PCC demonstrated increased functional connectivity between the precuneus, bilateral inferior parietal lobule and middle occipital gyrus. We also found correlations between the disease duration of PT and FC of PCC-right MTG (r = −0.616, p < 0.001). Conclusions: Unilateral PT patients could have abnormal FC to the PCC bilaterally in the brain. PCC, as a highly integrated brain area, is an example of nucleus that was involved in mediation between different neural networks. It might be a modulation core between visual network and auditory network. The decreased FC of MTG to PCC may indicate a down regulation of activity between PCC and auditory associated brain cortex. Decreased FC between limbic system (bilateral AI) and PCC may reflect the emotional message control in patient group. This study facilitated understanding of the underlying neuropathological process in patients with pulsatile tinnitus.

  12. Aspirin induces morphological transformation to the secretory state in isolated rabbit parietal cells.

    Science.gov (United States)

    Murthy, U K; Levine, R A

    1991-08-01

    The morphological response of rabbit parietal cells to aspirin was evaluated by grading several ultra-structural features including the extent of the tubulovesicular system, intracellular secretory canaliculi, and microvilli. After exposure of isolated parietal cells and gastric glands to aspirin or histamine, there was an approximately twofold increase in the ratio of secretory to nonsecretory parietal cells, and depletion of extracellular Ca2+ abolished the aspirin-induced morphological changes. Morphometry in parietal cells showed that aspirin induced a sixfold increase in secretory canalicular membrane elaboration. Aspirin potentiated histamine-induced parietal cell respiration and aminopyrine uptake ratio but did not increase basal respiration or aminopyrine uptake, suggesting an apparent dissociation from aspirin-induced morphological changes.

  13. CT of pleural abnormalities

    International Nuclear Information System (INIS)

    Webb, W.R.

    1995-01-01

    Briefly discussed were CT diagnosis of pleural thickening, CT technique for examining the pleura or pleuro-pulmonary disease, diagnosis of pleural collections, diagnosis of pleural fluid abnormalities in patients with pneumonia, pleural neoplasms, malignant (diffuse) mesothelioma, metastases, local fibrous tumor of the pleura (benign mesothelioma) (21 refs.)

  14. CT of pleural abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Webb, W R [California Univ., San Francisco, CA (United States). Dept. of Radiology

    1996-12-31

    Briefly discussed were CT diagnosis of pleural thickening, CT technique for examining the pleura or pleuro-pulmonary disease, diagnosis of pleural collections, diagnosis of pleural fluid abnormalities in patients with pneumonia, pleural neoplasms, malignant (diffuse) mesothelioma, metastases, local fibrous tumor of the pleura (benign mesothelioma) (21 refs.).

  15. Neurologic abnormalities in murderers.

    Science.gov (United States)

    Blake, P Y; Pincus, J H; Buckner, C

    1995-09-01

    Thirty-one individuals awaiting trial or sentencing for murder or undergoing an appeal process requested a neurologic examination through legal counsel. We attempted in each instance to obtain EEG, MRI or CT, and neuropsychological testing. Neurologic examination revealed evidence of "frontal" dysfunction in 20 (64.5%). There were symptoms or some other evidence of temporal lobe abnormality in nine (29%). We made a specific neurologic diagnosis in 20 individuals (64.5%), including borderline or full mental retardation (9) and cerebral palsy (2), among others. Neuropsychological testing revealed abnormalities in all subjects tested. There were EEG abnormalities in eight of the 20 subjects tested, consisting mainly of bilateral sharp waves with slowing. There were MRI or CT abnormalities in nine of the 19 subjects tested, consisting primarily of atrophy and white matter changes. Psychiatric diagnoses included paranoid schizophrenia (8), dissociative disorder (4), and depression (9). Virtually all subjects had paranoid ideas and misunderstood social situations. There was a documented history of profound, protracted physical abuse in 26 (83.8%) and of sexual abuse in 10 (32.3%). It is likely that prolonged, severe physical abuse, paranoia, and neurologic brain dysfunction interact to form the matrix of violent behavior.

  16. Using imaging to target the prefrontal cortex for transcranial magnetic stimulation studies in treatment-resistant depression

    OpenAIRE

    Johnson, Kevin A.; Ramsey, Dave; Kozel, Frank A.; Bohning, Daryl E.; Anderson, Berry; Nahas, Ziad; Sacke?m, Harold A.; George, Mark S.

    2006-01-01

    Structural imaging studies of the brains of patients with treatment-resistant depression (TRD) have found several abnormalities, including smaller hippocampus, orbitofrontal cortex, or pre?frontal cortex. Transcranial magnetic stimulation (TMS) is a noninvasive means of modulating brain activity, and has shown antidepressant treatment efficacy. 1 The initial methods used for targeting the prefrontal cortex are most likely insufficient. Herwig et al found that a common rule-based approach (the...

  17. Subtotal Ablation of Parietal Epithelial Cells Induces Crescent Formation

    Science.gov (United States)

    Sicking, Eva-Maria; Fuss, Astrid; Uhlig, Sandra; Jirak, Peggy; Dijkman, Henry; Wetzels, Jack; Engel, Daniel R.; Urzynicok, Torsten; Heidenreich, Stefan; Kriz, Wilhelm; Kurts, Christian; Ostendorf, Tammo; Floege, Jürgen; Smeets, Bart

    2012-01-01

    Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established an inducible transgenic mouse to allow subtotal ablation of PECs. Proteinuria developed during doxycycline-induced cellular ablation but fully reversed 26 days after termination of doxycycline administration. The ablation of PECs was focal, with only 30% of glomeruli exhibiting histologic changes; however, the number of PECs was reduced up to 90% within affected glomeruli. Ultrastructural analysis revealed disruption of PEC plasma membranes with cytoplasm shedding into Bowman’s space. Podocytes showed focal foot process effacement, which was the most likely cause for transient proteinuria. After >9 days of cellular ablation, the remaining PECs formed cellular extensions to cover the denuded Bowman’s capsule and expressed the activation marker CD44 de novo. The induced proliferation of PECs persisted throughout the observation period, resulting in the formation of typical cellular crescents with periglomerular infiltrate, albeit without accompanying proteinuria. In summary, subtotal ablation of PECs leads the remaining PECs to react with cellular activation and proliferation, which ultimately forms cellular crescents. PMID:22282596

  18. Parietal cells-new perspectives in glomerular disease.

    Science.gov (United States)

    Miesen, Laura; Steenbergen, Eric; Smeets, Bart

    2017-07-01

    In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman's capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and podocytes have a common mesenchymal origin and are the result of divergent differentiation during embryogenesis. Podocytes and PTECs are highly differentiated cells with well-established functions pertaining to the maintenance of the filtration barrier and transport, respectively. For PECs, no specific function other than a structural one has been known until recently. Possible important functions for PECs in the fate of the glomerulus in glomerular disease have now become apparent: (1) PECs may be involved in the replacement of lost podocytes; (2) PECs form the basis of extracapillary proliferative lesions and subsequent sclerosis in glomerular disease. In addition to the acknowledgement that PECs are crucial in glomerular disease, knowledge has been gained regarding the molecular processes driving the phenotypic changes and behavior of PECs. Understanding these molecular processes is important for the development of specific therapeutic approaches aimed at either stimulation of the regenerative function of PECs or inhibition of the pro-sclerotic action of PECs. In this review, we discuss recent advances pertaining to the role of PECs in glomerular regeneration and disease and address the major molecular processes involved.

  19. The regenerative potential of parietal epithelial cells in adult mice.

    Science.gov (United States)

    Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J

    2014-04-01

    Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman's capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glomerular hypertrophy was induced by progressive partial nephrectomies. Again, no significant podocyte replenishment was observed. Rather, labeled PECs exclusively invaded segments of the tuft affected by glomerulosclerosis, consistent with our previous findings. We next reassessed PEC recruitment in juvenile mice using a different reporter mouse and confirmed significant recruitment of labeled PECs onto the glomerular tuft. Moreover, some labeled cells on Bowman's capsule expressed podocyte markers, and cells on Bowman's capsule were also directly labeled in juvenile podocyte-specific Pod-rtTA transgenic mice. In 6-week-old mice, however, cells on Bowman's capsule no longer expressed podocyte-specific markers. Similarly, in human kidneys, some cells on Bowman's capsule expressed the podocyte marker synaptopodin from 2 weeks to 2 years of age but not at 7 years of age. In summary, podocyte regeneration from PECs could not be detected in aging mice or models of glomerular hypertrophy. We propose that a small fraction of committed podocytes reside on Bowman's capsule close to the vascular stalk and are recruited onto the glomerular tuft during infancy to adolescence in mice and humans.

  20. A Model of Representational Spaces in Human Cortex.

    Science.gov (United States)

    Guntupalli, J Swaroop; Hanke, Michael; Halchenko, Yaroslav O; Connolly, Andrew C; Ramadge, Peter J; Haxby, James V

    2016-06-01

    Current models of the functional architecture of human cortex emphasize areas that capture coarse-scale features of cortical topography but provide no account for population responses that encode information in fine-scale patterns of activity. Here, we present a linear model of shared representational spaces in human cortex that captures fine-scale distinctions among population responses with response-tuning basis functions that are common across brains and models cortical patterns of neural responses with individual-specific topographic basis functions. We derive a common model space for the whole cortex using a new algorithm, searchlight hyperalignment, and complex, dynamic stimuli that provide a broad sampling of visual, auditory, and social percepts. The model aligns representations across brains in occipital, temporal, parietal, and prefrontal cortices, as shown by between-subject multivariate pattern classification and intersubject correlation of representational geometry, indicating that structural principles for shared neural representations apply across widely divergent domains of information. The model provides a rigorous account for individual variability of well-known coarse-scale topographies, such as retinotopy and category selectivity, and goes further to account for fine-scale patterns that are multiplexed with coarse-scale topographies and carry finer distinctions. © The Author 2016. Published by Oxford University Press.

  1. The structure of the parietal pleura and its relationship to pleural liquid dynamics in sheep.

    Science.gov (United States)

    Albertine, K H; Wiener-Kronish, J P; Staub, N C

    1984-03-01

    We studied the parietal pleura of six sheep to obtain information on pleural structure, blood supply, and lymphatic drainage. In the strict sense, the parietal pleura is composed of a single layer of mesothelial cells and a uniform layer of loose, irregular connective tissue (about 23 micron in width) subjacent to the mesothelial cells. The parietal pleural blood vessels are 10-15 micron from the pleural space. Tracer substances put in the pleural space are removed at specific locations. Colloidal carbon and chick red blood cells are cleared by the parietal pleural lymphatics located over the intercostal spaces at the caudal end of the thoracic wall and over the lateral sides of the pericardial sac. In these areas the mesothelial cells have specialized openings, the stomata, that directly communicate with the underlying lymphatic lacunae. Cells and particulate matter in the pleural space are cleared only by the parietal pleural lymphatics. Compared to the visceral pleura, we believe the thinness of the parietal pleura, the closeness of its blood vessels to the pleural space, and its specialized lymphatic clearance pathways, together indicate that the parietal pleura plays a major role in pleural liquid and protein dynamics in sheep.

  2. Increased density of DISC1-immunoreactive oligodendroglial cells in fronto-parietal white matter of patients with paranoid schizophrenia.

    Science.gov (United States)

    Bernstein, Hans-Gert; Jauch, Esther; Dobrowolny, Henrik; Mawrin, Christian; Steiner, Johann; Bogerts, Bernhard

    2016-09-01

    Profound white matter abnormalities have repeatedly been described in schizophrenia, which involve the altered expression of numerous oligodendrocyte-associated genes. Transcripts of the disrupted-in-schizophrenia 1 (DISC1) gene, a key susceptibility factor in schizophrenia, have recently been shown to be expressed by oligodendroglial cells and to negatively regulate oligodendrocyte differentiation and maturation. To learn more about the putative role(s) of oligodendroglia-associated DISC1 in schizophrenia, we analyzed the density of DISC1-immunoreactive oligodendrocytes in the fronto-parietal white matter in postmortem brains of patients with schizophrenia. Compared with controls (N = 12) and cases with undifferentiated/residual schizophrenia (N = 6), there was a significantly increased density of DISC1-expressing glial cells in paranoid schizophrenia (N = 12), which unlikely resulted from neuroleptic treatment. Pathophysiologically, over-expression of DISC1 protein(s) in white matter oligodendrocytes might add to the reduced levels of two myelin markers, 2',3'-cyclic-nucleotide 3'-phosphodiesterase and myelin basic protein in schizophrenia. Moreover, it might significantly contribute to cell cycle abnormalities as well as to deficits in oligodendroglial cell differentiation and maturation found in schizophrenia.

  3. Nitrofurantoin and congenital abnormalities

    DEFF Research Database (Denmark)

    Czeizel, A.E.; Rockenbauer, M.; Sørensen, Henrik Toft

    2001-01-01

    or fetuses with Down’s syndrome (patient controls), 23 (2.8%) pregnant women were treated with nitrofurantoin. The above differences between population controls and cases may be connected with recall bias, because the case-control pair analysis did not indicate a teratogenic potential of nitrofurantoin use......Objective: To study human teratogenic potential of oral nitrofurantoin treatment during pregnancy. Materials and Methods: Pair analysis of cases with congenital abnormalities and matched population controls in the population-based dataset of the Hungarian Case-Control Surveillance of Congenital...... during the second and the third months of gestation, i.e. in the critical period for major congenital abnormalities. Conclusion: Treatment with nitrofurantoin during pregnancy does not present detectable teratogenic risk to the fetus....

  4. Neurological abnormalities predict disability

    DEFF Research Database (Denmark)

    Poggesi, Anna; Gouw, Alida; van der Flier, Wiesje

    2014-01-01

    To investigate the role of neurological abnormalities and magnetic resonance imaging (MRI) lesions in predicting global functional decline in a cohort of initially independent-living elderly subjects. The Leukoaraiosis And DISability (LADIS) Study, involving 11 European centres, was primarily aimed...... at evaluating age-related white matter changes (ARWMC) as an independent predictor of the transition to disability (according to Instrumental Activities of Daily Living scale) or death in independent elderly subjects that were followed up for 3 years. At baseline, a standardized neurological examination.......0 years, 45 % males), 327 (51.7 %) presented at the initial visit with ≥1 neurological abnormality and 242 (38 %) reached the main study outcome. Cox regression analyses, adjusting for MRI features and other determinants of functional decline, showed that the baseline presence of any neurological...

  5. Live Imaging of Mitosis in the Developing Mouse Embryonic Cortex

    OpenAIRE

    Pilaz, Louis-Jan; Silver, Debra L.

    2014-01-01

    Although of short duration, mitosis is a complex and dynamic multi-step process fundamental for development of organs including the brain. In the developing cerebral cortex, abnormal mitosis of neural progenitors can cause defects in brain size and function. Hence, there is a critical need for tools to understand the mechanisms of neural progenitor mitosis. Cortical development in rodents is an outstanding model for studying this process. Neural progenitor mitosis is commonly examined in fixe...

  6. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  7. Regulating prefrontal cortex activation

    DEFF Research Database (Denmark)

    Aznar, Susana; Klein, Anders Bue

    2013-01-01

    The prefrontal cortex (PFC) is involved in mediating important higher-order cognitive processes such as decision making, prompting thereby our actions. At the same time, PFC activation is strongly influenced by emotional reactions through its functional interaction with the amygdala...... of emotion-based actions, such as addiction and other impulse-related behaviors. In this review, we give an overview of the 5-HT2A receptor distribution (neuronal, intracellular, and anatomical) along with its functional and physiological effect on PFC activation, and how that relates to more recent findings...... of a regulatory effect of the PFC on the emotional control of our actions....

  8. Hair Shaft Abnormality in Children: a Narrative Review

    Directory of Open Access Journals (Sweden)

    Ghasem Rahmatpour Rokni

    2017-08-01

    Full Text Available Background Hair is an ectodermal structure, and its formation is regulated by master genes important in embryology. Hair shaft consists of three major regions: the medulla, cortex and cuticle. Hair shaft abnormality will divide structural hair abnormalities into two broad categories - those associated with increased hair fragility and those not associated with increased hair fragility. We conducted a review study to assess hair shaft abnormality in children. Materials and Methods We conducted a review of all papers published on hair shaft abnormalities. A literature search was performed using PubMed, Scopus and Google Scholar on papers publish from 1990 to 2016. The search terms were: hair shaft abnormality, Hair loss, Hair fragility. All abstracts and full text English-language articles were studied. Results While common developmental and structural features are shared in hair follicles and hair shafts. Anomalies of the hair shaft are separated into those with and those without increased hair fragility. Conclusion Although hair has no vital function, it may serve as an indicator for human health. Clinical and morphological hair abnormalities can be clues to specific complex disorders. Hair shaft abnormalities can be inherited or acquired, can reflect a local problem or a systemic disease.

  9. Transient MRI abnormalities associated with partial status epilepticus: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Amato, Carmelo; Elia, Maurizio; Musumeci, Sebastiano A; Bisceglie, Pierluigi; Moschini, Massimo

    2001-04-01

    We report the case of an 18-year-old woman who presented a long-lasting cluster of partial seizures, and MRI cortical abnormalities localized in the left parietal lobe. The MRI changes correlated with the site of the epileptogenic focus, and disappeared within 2 weeks. The recognition of these reversible MRI abnormalities, which are presumably due to a temporary alteration of blood-brain barrier in the epileptogenic zone with subsequent edema, and are not associated with any underlying organic conditions, is extremely useful in the medical management of the patient and allows to avoid other invasive diagnostic procedures.

  10. Transient MRI abnormalities associated with partial status epilepticus: a case report

    International Nuclear Information System (INIS)

    Amato, Carmelo; Elia, Maurizio; Musumeci, Sebastiano A.; Bisceglie, Pierluigi; Moschini, Massimo

    2001-01-01

    We report the case of an 18-year-old woman who presented a long-lasting cluster of partial seizures, and MRI cortical abnormalities localized in the left parietal lobe. The MRI changes correlated with the site of the epileptogenic focus, and disappeared within 2 weeks. The recognition of these reversible MRI abnormalities, which are presumably due to a temporary alteration of blood-brain barrier in the epileptogenic zone with subsequent edema, and are not associated with any underlying organic conditions, is extremely useful in the medical management of the patient and allows to avoid other invasive diagnostic procedures

  11. Isolation, culture and adenoviral transduction of parietal cells from mouse gastric mucosa

    International Nuclear Information System (INIS)

    Gliddon, Briony L; Nguyen, Nhung V; Gunn, Priscilla A; Gleeson, Paul A; Driel, Ian R van

    2008-01-01

    Here we describe a method for the isolation of intact gastric glands from mice and primary culture and transfection of mouse gastric epithelial cells. Collagenase digestion of PBS-perfused mouse stomachs released large intact gastric glands that were plated on a basement membrane matrix. The heterogeneous gland cell cultures typically contain ∼60% parietal cells. Isolated mouse parietal cells remain viable in culture for up to 5 days and react strongly with an antibody specific to the gastric H + /K + ATPase. Isolated intact mouse gastric glands and primary cultures of mouse parietal cells respond to the secretagogue, histamine. Typical morphological changes from a resting to an acid-secreting active parietal cell were observed. In resting cultures of mouse parietal cells, the H + /K + ATPase displayed a cytoplasmic punctate staining pattern consistent with tubulovesicle element structures. Following histamine stimulation, an expansion of internal apical vacuole structures was observed together with a pronounced redistribution of the H + /K + ATPase from the cytoplasm to the apical vacuoles. A reproducible procedure to express genes of interest exogenously in these cultures of mouse parietal cells was also established. This method combines recombinant adenoviral transduction with magnetic field-assisted transfection resulting in ∼30% transduced parietal cells. Adenoviral-transduced parietal cells maintain their ability to undergo agonist-induced activation. This protocol will be useful for the isolation, culture and expression of genes in parietal cells from genetically modified mice and as such will be an invaluable tool for studying the complex exocytic and endocytic trafficking events of the H + /K + ATPase which underpin the regulation of acid secretion

  12. The Regenerative Potential of Parietal Epithelial Cells in Adult Mice

    Science.gov (United States)

    Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H.; Floege, Jürgen; Smeets, Bart

    2014-01-01

    Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman’s capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glomerular hypertrophy was induced by progressive partial nephrectomies. Again, no significant podocyte replenishment was observed. Rather, labeled PECs exclusively invaded segments of the tuft affected by glomerulosclerosis, consistent with our previous findings. We next reassessed PEC recruitment in juvenile mice using a different reporter mouse and confirmed significant recruitment of labeled PECs onto the glomerular tuft. Moreover, some labeled cells on Bowman’s capsule expressed podocyte markers, and cells on Bowman’s capsule were also directly labeled in juvenile podocyte-specific Pod-rtTA transgenic mice. In 6-week-old mice, however, cells on Bowman’s capsule no longer expressed podocyte-specific markers. Similarly, in human kidneys, some cells on Bowman’s capsule expressed the podocyte marker synaptopodin from 2 weeks to 2 years of age but not at 7 years of age. In summary, podocyte regeneration from PECs could not be detected in aging mice or models of glomerular hypertrophy. We propose that a small fraction of committed podocytes reside on Bowman’s capsule close to the vascular stalk and are recruited onto the glomerular tuft during infancy to adolescence in mice and humans. PMID:24408873

  13. Podocyte and Parietal Epithelial Cell Interactions in Health and Disease.

    Science.gov (United States)

    Al Hussain, Turki; Al Mana, Hadeel; Hussein, Maged H; Akhtar, Mohammed

    2017-01-01

    The glomerulus has 3 resident cells namely mesangial cells that produce the mesangial matrix, endothelial cells that line the glomerular capillaries, and podocytes that cover the outer surface of the glomerular basement membrane. Parietal epithelial cells (PrECs), which line the Bowman's capsule are not part of the glomerular tuft but may have an important role in the normal function of the glomerulus. A significant progress has been made in recent years regarding our understanding of the role and function of these cells in normal kidney and in kidneys with various types of glomerulopathy. In crescentic glomerulonephritis necrotizing injury of the glomerular tuft results in activation and leakage of fibrinogen which provides the trigger for excessive proliferation of PrECs giving rise to glomerular crescents. In cases of collapsing glomerulopathy, podocyte injury causes collapse of the glomerular capillaries and activation and proliferation of PrECs, which accumulate within the urinary space in the form of pseudocrescents. Many of the noninflammatory glomerular lesions such as focal segmental glomerulosclerosis and global glomerulosclerosis also result from podocyte injury which causes variable loss of podocytes. In these cases podocyte injury leads to activation of PrECs that extend on to the glomerular tuft where they cause segmental and/or global sclerosis by producing excess matrix, resulting in obliteration of the capillary lumina. In diabetic nephropathy, in addition to increased matrix production in the mesangium and glomerular basement membranes, increased loss of podocytes is an important determinant of long-term prognosis. Contrary to prior belief there is no convincing evidence for an active podocyte proliferation in any of the above mentioned glomerulopathies.

  14. Estimates of segregation and overlap of functional connectivity networks in the human cerebral cortex.

    Science.gov (United States)

    Yeo, B T Thomas; Krienen, Fenna M; Chee, Michael W L; Buckner, Randy L

    2014-03-01

    The organization of the human cerebral cortex has recently been explored using techniques for parcellating the cortex into distinct functionally coupled networks. The divergent and convergent nature of cortico-cortical anatomic connections suggests the need to consider the possibility of regions belonging to multiple networks and hierarchies among networks. Here we applied the Latent Dirichlet Allocation (LDA) model and spatial independent component analysis (ICA) to solve for functionally coupled cerebral networks without assuming that cortical regions belong to a single network. Data analyzed included 1000 subjects from the Brain Genomics Superstruct Project (GSP) and 12 high quality individual subjects from the Human Connectome Project (HCP). The organization of the cerebral cortex was similar regardless of whether a winner-take-all approach or the more relaxed constraints of LDA (or ICA) were imposed. This suggests that large-scale networks may function as partially isolated modules. Several notable interactions among networks were uncovered by the LDA analysis. Many association regions belong to at least two networks, while somatomotor and early visual cortices are especially isolated. As examples of interaction, the precuneus, lateral temporal cortex, medial prefrontal cortex and posterior parietal cortex participate in multiple paralimbic networks that together comprise subsystems of the default network. In addition, regions at or near the frontal eye field and human lateral intraparietal area homologue participate in multiple hierarchically organized networks. These observations were replicated in both datasets and could be detected (and replicated) in individual subjects from the HCP. © 2013.

  15. Equipment abnormality monitoring device

    International Nuclear Information System (INIS)

    Ando, Yasumasa

    1991-01-01

    When an operator hears sounds in a plantsite, the operator compares normal sounds of equipment which he previously heard and remembered with sounds he actually hears, to judge if they are normal or abnormal. According to the method, there is a worry that abnormal conditions can not be appropriately judged in a case where the number of objective equipments is increased and in a case that the sounds are changed gradually slightly. Then, the device of the present invention comprises a plurality of monitors for monitoring the operation sound of equipments, a recording/reproducing device for recording and reproducing the signals, a selection device for selecting the reproducing signals among the recorded signals, an acoustic device for converting the signals to sounds, a switching device for switching the signals to be transmitted to the acoustic device between to signals of the monitor and the recording/reproducing signals. The abnormality of the equipments can be determined easily by comparing the sounds representing the operation conditions of equipments for controlling the plant operation and the sounds recorded in their normal conditions. (N.H.)

  16. Similar cortical but not subcortical gray matter abnormalities in women with posttraumatic stress disorder with versus without dissociative identity disorder.

    Science.gov (United States)

    Chalavi, Sima; Vissia, Eline M; Giesen, Mechteld E; Nijenhuis, Ellert R S; Draijer, Nel; Barker, Gareth J; Veltman, Dick J; Reinders, Antje A T S

    2015-03-30

    Neuroanatomical evidence on the relationship between posttraumatic stress disorder (PTSD) and dissociative disorders is still lacking. We acquired brain structural magnetic resonance imaging (MRI) scans from 17 patients with dissociative identity disorder (DID) and co-morbid PTSD (DID-PTSD) and 16 patients with PTSD but without DID (PTSD-only), and 32 healthy controls (HC), and compared their whole-brain cortical and subcortical gray matter (GM) morphological measurements. Associations between GM measurements and severity of dissociative and depersonalization/derealization symptoms or lifetime traumatizing events were evaluated in the patient groups. DID-PTSD and PTSD-only patients, compared with HC, had similarly smaller cortical GM volumes of the whole brain and of frontal, temporal and insular cortices. DID-PTSD patients additionally showed smaller hippocampal and larger pallidum volumes relative to HC, and larger putamen and pallidum volumes relative to PTSD-only. Severity of lifetime traumatizing events and volume of the hippocampus were negatively correlated. Severity of dissociative and depersonalization/derealization symptoms correlated positively with volume of the putamen and pallidum, and negatively with volume of the inferior parietal cortex. Shared abnormal brain structures in DID-PTSD and PTSD-only, small hippocampal volume in DID-PTSD, more severe lifetime traumatizing events in DID-PTSD compared with PTSD-only, and negative correlations between lifetime traumatizing events and hippocampal volume suggest a trauma-related etiology for DID. Our results provide neurobiological evidence for the side-by-side nosological classification of PTSD and DID in the DSM-5. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Differential frontal-parietal phase synchrony during hypnosis as a function of hypnotic suggestibility.

    Science.gov (United States)

    Terhune, Devin Blair; Cardeña, Etzel; Lindgren, Magnus

    2011-10-01

    Spontaneous dissociative alterations in awareness and perception among highly suggestible individuals following a hypnotic induction may result from disruptions in the functional coordination of the frontal-parietal network. We recorded EEG and self-reported state dissociation in control and hypnosis conditions in two sessions with low and highly suggestible participants. Highly suggestible participants reliably experienced greater state dissociation and exhibited lower frontal-parietal phase synchrony in the alpha2 frequency band during hypnosis than low suggestible participants. These findings suggest that highly suggestible individuals exhibit a disruption of the frontal-parietal network that is only observable following a hypnotic induction. Copyright © 2011 Society for Psychophysiological Research.

  18. Abnormal pressures as hydrodynamic phenomena

    Science.gov (United States)

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  19. The role of human ventral visual cortex in motion perception

    Science.gov (United States)

    Saygin, Ayse P.; Lorenzi, Lauren J.; Egan, Ryan; Rees, Geraint; Behrmann, Marlene

    2013-01-01

    Visual motion perception is fundamental to many aspects of visual perception. Visual motion perception has long been associated with the dorsal (parietal) pathway and the involvement of the ventral ‘form’ (temporal) visual pathway has not been considered critical for normal motion perception. Here, we evaluated this view by examining whether circumscribed damage to ventral visual cortex impaired motion perception. The perception of motion in basic, non-form tasks (motion coherence and motion detection) and complex structure-from-motion, for a wide range of motion speeds, all centrally displayed, was assessed in five patients with a circumscribed lesion to either the right or left ventral visual pathway. Patients with a right, but not with a left, ventral visual lesion displayed widespread impairments in central motion perception even for non-form motion, for both slow and for fast speeds, and this held true independent of the integrity of areas MT/V5, V3A or parietal regions. In contrast with the traditional view in which only the dorsal visual stream is critical for motion perception, these novel findings implicate a more distributed circuit in which the integrity of the right ventral visual pathway is also necessary even for the perception of non-form motion. PMID:23983030

  20. Motor demand-dependent activation of ipsilateral motor cortex.

    Science.gov (United States)

    Buetefisch, Cathrin M; Revill, Kate Pirog; Shuster, Linda; Hines, Benjamin; Parsons, Michael

    2014-08-15

    The role of ipsilateral primary motor cortex (M1) in hand motor control during complex task performance remains controversial. Bilateral M1 activation is inconsistently observed in functional (f)MRI studies of unilateral hand performance. Two factors limit the interpretation of these data. As the motor tasks differ qualitatively in these studies, it is conceivable that M1 contributions differ with the demand on skillfulness. Second, most studies lack the verification of a strictly unilateral execution of the motor task during the acquisition of imaging data. Here, we use fMRI to determine whether ipsilateral M1 activity depends on the demand for precision in a pointing task where precision varied quantitatively while movement trajectories remained equal. Thirteen healthy participants used an MRI-compatible joystick to point to targets of four different sizes in a block design. A clustered acquisition technique allowed simultaneous fMRI/EMG data collection and confirmed that movements were strictly unilateral. Accuracy of performance increased with target size. Overall, the pointing task revealed activation in contralateral and ipsilateral M1, extending into contralateral somatosensory and parietal areas. Target size-dependent activation differences were found in ipsilateral M1 extending into the temporal/parietal junction, where activation increased with increasing demand on accuracy. The results suggest that ipsilateral M1 is active during the execution of a unilateral motor task and that its activity is modulated by the demand on precision. Copyright © 2014 the American Physiological Society.

  1. Decreased Fronto-Parietal and Increased Default Mode Network Activation is Associated with Subtle Cognitive Deficits in Elderly Controls

    Directory of Open Access Journals (Sweden)

    Davide Zanchi

    2017-12-01

    Full Text Available Background: Cognitive functions progressively deteriorate during aging and neurodegenerative diseases. The present study aims at investigating differences in working memory performance as well as functional brain changes during the earliest stages of cognitive decline in health elderly individuals. Methods: 62 elderly individuals (41 females, including 41 controls (35 females and 21 middle cognitive impairment subjects (6 females, underwent neuropsychological assessment at baseline and an fMRI examination in a N-back paradigm contrasting 2-back vs. 0-back condition. Upon a 18 months follow-up, we identified stable controls (sCON with preserved cognition and deteriorating controls (dCON with -1SD decrease of performances in at least two neuropsychological tests. Data analyses included accuracy and reaction time (RT for the 2-back condition and general linear model (GLM for the fMRI sequence. Results: At the behavioral level, sCON and dCON performed better than MCI in terms of accuracy and reaction time. At the brain level, functional differences in regions of the fronto-parietal network (FPN and of the Default Mode Network (DFM were observed. Significantly lower neural activations in the bilateral inferior and middle frontal gyri were found in MCI versus both dCON / sCON and for dCON versus sCON. Significantly increased activations in the anterior cingulate cortex and posterior cingulate cortex and bilateral insula were found in MCI versus both dCON / sCON and in dCON versus sCON. Conclusion: The present study suggests that brain functional changes in FPN and DMN anticipate differences in cognitive performance in healthy elderly individuals with subsequent subtle cognitive decline.

  2. Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.

    Science.gov (United States)

    Fernald, Charles D.

    1980-01-01

    Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

  3. Modeling Conflict and Error in the Medial Frontal Cortex

    Science.gov (United States)

    Mayer, Andrew R.; Teshiba, Terri M.; Franco, Alexandre R.; Ling, Josef; Shane, Matthew S.; Stephen, Julia M.; Jung, Rex E.

    2014-01-01

    Despite intensive study, the role of the dorsal medial frontal cortex (dMFC) in error monitoring and conflict processing remains actively debated. The current experiment manipulated conflict type (stimulus conflict only or stimulus and response selection conflict) and utilized a novel modeling approach to isolate error and conflict variance during a multimodal numeric Stroop task. Specifically, hemodynamic response functions resulting from two statistical models that either included or isolated variance arising from relatively few error trials were directly contrasted. Twenty-four participants completed the task while undergoing event-related functional magnetic resonance imaging on a 1.5-Tesla scanner. Response times monotonically increased based on the presence of pure stimulus or stimulus and response selection conflict. Functional results indicated that dMFC activity was present during trials requiring response selection and inhibition of competing motor responses, but absent during trials involving pure stimulus conflict. A comparison of the different statistical models suggested that relatively few error trials contributed to a disproportionate amount of variance (i.e., activity) throughout the dMFC, but particularly within the rostral anterior cingulate gyrus (rACC). Finally, functional connectivity analyses indicated that an empirically derived seed in the dorsal ACC/pre-SMA exhibited strong connectivity (i.e., positive correlation) with prefrontal and inferior parietal cortex but was anticorrelated with the default-mode network. An empirically derived seed from the rACC exhibited the opposite pattern, suggesting that sub-regions of the dMFC exhibit different connectivity patterns with other large scale networks implicated in internal mentations such as daydreaming (default-mode) versus the execution of top-down attentional control (fronto-parietal). PMID:21976411

  4. Modeling conflict and error in the medial frontal cortex.

    Science.gov (United States)

    Mayer, Andrew R; Teshiba, Terri M; Franco, Alexandre R; Ling, Josef; Shane, Matthew S; Stephen, Julia M; Jung, Rex E

    2012-12-01

    Despite intensive study, the role of the dorsal medial frontal cortex (dMFC) in error monitoring and conflict processing remains actively debated. The current experiment manipulated conflict type (stimulus conflict only or stimulus and response selection conflict) and utilized a novel modeling approach to isolate error and conflict variance during a multimodal numeric Stroop task. Specifically, hemodynamic response functions resulting from two statistical models that either included or isolated variance arising from relatively few error trials were directly contrasted. Twenty-four participants completed the task while undergoing event-related functional magnetic resonance imaging on a 1.5-Tesla scanner. Response times monotonically increased based on the presence of pure stimulus or stimulus and response selection conflict. Functional results indicated that dMFC activity was present during trials requiring response selection and inhibition of competing motor responses, but absent during trials involving pure stimulus conflict. A comparison of the different statistical models suggested that relatively few error trials contributed to a disproportionate amount of variance (i.e., activity) throughout the dMFC, but particularly within the rostral anterior cingulate gyrus (rACC). Finally, functional connectivity analyses indicated that an empirically derived seed in the dorsal ACC/pre-SMA exhibited strong connectivity (i.e., positive correlation) with prefrontal and inferior parietal cortex but was anti-correlated with the default-mode network. An empirically derived seed from the rACC exhibited the opposite pattern, suggesting that sub-regions of the dMFC exhibit different connectivity patterns with other large scale networks implicated in internal mentations such as daydreaming (default-mode) versus the execution of top-down attentional control (fronto-parietal). Copyright © 2011 Wiley Periodicals, Inc.

  5. Modulation of Speech Motor Learning with Transcranial Direct Current Stimulation of the Inferior Parietal Lobe

    Directory of Open Access Journals (Sweden)

    Mickael L. D. Deroche

    2017-12-01

    Full Text Available The inferior parietal lobe (IPL is a region of the cortex believed to participate in speech motor learning. In this study, we investigated whether transcranial direct current stimulation (tDCS of the IPL could influence the extent to which healthy adults (1 adapted to a sensory alteration of their own auditory feedback, and (2 changed their perceptual representation. Seventy subjects completed three tasks: a baseline perceptual task that located the phonetic boundary between the vowels /e/ and /a/; a sensorimotor adaptation task in which subjects produced the word “head” under conditions of altered or unaltered feedback; and a post-adaptation perceptual task identical to the first. Subjects were allocated to four groups which differed in current polarity and feedback manipulation. Subjects who received anodal tDCS to their IPL (i.e., presumably increasing cortical excitability lowered their first formant frequency (F1 by 10% in opposition to the upward shift in F1 in their auditory feedback. Subjects who received the same stimulation with unaltered feedback did not change their production. Subjects who received cathodal tDCS to their IPL (i.e., presumably decreasing cortical excitability showed a 5% adaptation to the F1 alteration similar to subjects who received sham tDCS. A subset of subjects returned a few days later to reiterate the same protocol but without tDCS, enabling assessment of any facilitatory effects of the previous tDCS. All subjects exhibited a 5% adaptation effect. In addition, across all subjects and for the two recording sessions, the phonetic boundary was shifted toward the vowel /e/ being repeated, consistently with the selective adaptation effect, but a correlation between perception and production suggested that anodal tDCS had enhanced this perceptual shift. In conclusion, we successfully demonstrated that anodal tDCS could (1 enhance the motor adaptation to a sensory alteration, and (2 potentially affect the

  6. Exercises to Improve Gait Abnormalities

    Science.gov (United States)

    ... Articles Directories Videos Resources Contact Exercises to Improve Gait Abnormalities Home » Article Categories » Exercise and Fitness Font Size: A A A A Exercises to Improve Gait Abnormalities Next Page The manner of how a ...

  7. Pregnancy Complications: Umbilical Cord Abnormalities

    Science.gov (United States)

    ... Umbilical cord abnormalities Umbilical cord abnormalities Now playing: E-mail to a friend Please fill in all fields. ... blood supply) to the baby. The two arteries transport waste from the baby to the placenta (where ...

  8. The Oft-Neglected Role of Parietal EEG Asymmetry and Risk for Major Depressive Disorder

    Science.gov (United States)

    Stewart, Jennifer L.; Towers, David N.; Coan, James A.; Allen, John J.B.

    2010-01-01

    Relatively less right parietal activity may reflect reduced arousal and signify risk for major depressive disorder (MDD). Inconsistent findings with parietal electroencephalographic (EEG) asymmetry, however, suggest issues such as anxiety comorbidity and sex differences have yet to be resolved. Resting parietal EEG asymmetry was assessed in 306 individuals (31% male) with (n = 143) and without (n = 163) a DSM-IV diagnosis of lifetime MDD and no comorbid anxiety disorders. Past MDD+ women displayed relatively less right parietal activity than current MDD+ and MDD- women, replicating prior work. Recent caffeine intake, an index of arousal, moderated the relationship between depression and EEG asymmetry for women and men. Findings suggest that sex differences and arousal should be examined in studies of depression and regional brain activity. PMID:20525011

  9. Cortex and amygdala morphology in psychopathy.

    Science.gov (United States)

    Boccardi, Marina; Frisoni, Giovanni B; Hare, Robert D; Cavedo, Enrica; Najt, Pablo; Pievani, Michela; Rasser, Paul E; Laakso, Mikko P; Aronen, Hannu J; Repo-Tiihonen, Eila; Vaurio, Olli; Thompson, Paul M; Tiihonen, Jari

    2011-08-30

    Psychopathy is characterized by abnormal emotional processes, but only recent neuroimaging studies have investigated its cerebral correlates. The study aim was to map local differences of cortical and amygdalar morphology. Cortical pattern matching and radial distance mapping techniques were used to analyze the magnetic resonance images of 26 violent male offenders (age: 32±8) with psychopathy diagnosed using the Psychopathy Checklist-Revised (PCL-R) and no schizophrenia spectrum disorders, and in matched controls (age: 35± sp="0.12"/>11). The cortex displayed up to 20% reduction in the orbitofrontal and midline structures (corrected pamygdala (corrected p=0.05 on the right; and symmetrical pattern on the left). Psychopathy features specific morphology of the main cerebral structures involved in cognitive and emotional processing, consistent with clinical and functional data, and with a hypothesis of an alternative evolutionary brain development. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. The chronic encephalopathy of Parry Romberg Syndrome and en coupe de sabre with a 31-year-history in a West Indian woman: clinical, immunologic and neuroimaging abnormalities

    Directory of Open Access Journals (Sweden)

    Karan Seegobin

    2016-09-01

    Full Text Available We describe a case of Parry Romberg syndrome/ en coupe de sabre in a woman whose disease started as seizures at age 8 but was diagnosed at the age 39. During these 31 years she got married, completed a first degree at university, had two successful pregnancies and has been gainfully employed. The features of generalized tonic-clonic seizures, autoimmune abnormalities, ocular abnormalities, morphea en coup de sabre and brain imaging abnormalities were present. Areas of parietal lobe cerebral calcification were encountered on the computed tomographic scan and bilateral periventricular white matter changes on the magnetic resonance imaging with frontal, temporal and parietal lobe brain atrophy ipsilateral to the facial hemiatrophy. Clinical, immunologic and neuroradiological abnormalities are discussed. In some cases, this illness can run a benign and stable course.

  11. Levels of integration in cognitive control and sequence processing in the prefrontal cortex.

    Science.gov (United States)

    Bahlmann, Jörg; Korb, Franziska M; Gratton, Caterina; Friederici, Angela D

    2012-01-01

    Cognitive control is necessary to flexibly act in changing environments. Sequence processing is needed in language comprehension to build the syntactic structure in sentences. Functional imaging studies suggest that sequence processing engages the left ventrolateral prefrontal cortex (PFC). In contrast, cognitive control processes additionally recruit bilateral rostral lateral PFC regions. The present study aimed to investigate these two types of processes in one experimental paradigm. Sequence processing was manipulated using two different sequencing rules varying in complexity. Cognitive control was varied with different cue-sets that determined the choice of a sequencing rule. Univariate analyses revealed distinct PFC regions for the two types of processing (i.e. sequence processing: left ventrolateral PFC and cognitive control processing: bilateral dorsolateral and rostral PFC). Moreover, in a common brain network (including left lateral PFC and intraparietal sulcus) no interaction between sequence and cognitive control processing was observed. In contrast, a multivariate pattern analysis revealed an interaction of sequence and cognitive control processing, such that voxels in left lateral PFC and parietal cortex showed different tuning functions for tasks involving different sequencing and cognitive control demands. These results suggest that the difference between the process of rule selection (i.e. cognitive control) and the process of rule-based sequencing (i.e. sequence processing) find their neuronal underpinnings in distinct activation patterns in lateral PFC. Moreover, the combination of rule selection and rule sequencing can shape the response of neurons in lateral PFC and parietal cortex.

  12. At the intersection of attention and memory: the mechanistic role of the posterior parietal lobe in working memory

    Science.gov (United States)

    Berryhill, Marian E.; Chein, Jason; Olson, Ingrid R.

    2011-01-01

    Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The pure storage hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the internal attention hypothesis proposes that the PPC functions as an attention-based storage and refreshing mechanism deployable as an alternative to material-specific rehearsal. These models were tested in patients with bilateral PPC lesions. Our findings discount the pure storage hypothesis because variables indexing storage capacity and longevity were not disproportionately affected by PPC damage. Instead, our data support the internal attention account by showing that (a) normal participants tend to use a rehearsal-based WM maintenance strategy for recall tasks but not for recognition tasks; (b) patients with PPC lesions performed normally on WM tasks that relied on material-specific rehearsal strategies but poorly on WM tasks that relied on attention-based maintenance strategies and patient strategy usage could be shifted by task or instructions; (c) patients’ memory deficits extended into the long-term domain. These findings suggest that the PPC maintains or shifts internal attention among the representations of items in WM. PMID:21345344

  13. At the intersection of attention and memory: the mechanistic role of the posterior parietal lobe in working memory.

    Science.gov (United States)

    Berryhill, Marian E; Chein, Jason; Olson, Ingrid R

    2011-04-01

    Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The pure storage hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the internal attention hypothesis proposes that the PPC functions as an attention-based storage and refreshing mechanism deployable as an alternative to material-specific rehearsal. These models were tested in patients with bilateral PPC lesions. Our findings discount the pure storage hypothesis because variables indexing storage capacity and longevity were not disproportionately affected by PPC damage. Instead, our data support the internal attention account by showing that (a) normal participants tend to use a rehearsal-based WM maintenance strategy for recall tasks but not for recognition tasks; (b) patients with PPC lesions performed normally on WM tasks that relied on material-specific rehearsal strategies but poorly on WM tasks that relied on attention-based maintenance strategies and patient strategy usage could be shifted by task or instructions; (c) patients' memory deficits extended into the long-term domain. These findings suggest that the PPC maintains or shifts internal attention among the representations of items in WM. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. [Functional connectivity of temporal parietal junction in online game addicts:a resting-state functional magnetic resonance imaging study].

    Science.gov (United States)

    Yuan, Ji; Qian, Ruobing; Lin, Bin; Fu, Xianming; Wei, Xiangpin; Weng, Chuanbo; Niu, Chaoshi; Wang, Yehan

    2014-02-11

    To explore the functions of temporal parietal junction (TPJ) as parts of attention networks in the pathogenesis of online game addiction using resting-state functional magnetic resonance imaging (fMRI). A total of 17 online game addicts (OGA) were recruited as OGA group and 17 healthy controls during the same period were recruited as CON group. The neuropsychological tests were performed for all of them to compare the inter-group differences in the results of Internet Addiction Test (IAT) and attention functions. All fMRI data were preprocessed after resting-state fMRI scanning. Then left and right TPJ were selected as regions of interest (ROIs) to calculate the linear correlation between TPJ and entire brain to compare the inter-group differences. Obvious differences existed between OGA group (71 ± 5 scores) and CON group (19 ± 7 scores) in the IAT results and attention function (P online game addicts showed decreased functional connectivity with bilateral ventromedial prefrontal cortex (VMPFC), bilateral hippocampal gyrus and bilateral amygdaloid nucleus, but increased functional connectivity with right cuneus.However, left TPJ demonstrated decreased functional connectivity with bilateral superior frontal gyrus and bilateral middle frontal gyrus, but increased functional connectivity with bilateral cuneus (P online game addicts.It suggests that TPJ is an important component of attention networks participating in the generation of online game addiction.

  15. Interpersonal brain synchronization in the right temporo-parietal junction during face-to-face economic exchange.

    Science.gov (United States)

    Tang, Honghong; Mai, Xiaoqin; Wang, Shun; Zhu, Chaozhe; Krueger, Frank; Liu, Chao

    2016-01-01

    In daily life, interpersonal interactions are influenced by uncertainty about other people's intentions. Face-to-face (FF) interaction reduces such uncertainty by providing external visible cues such as facial expression or body gestures and facilitates shared intentionality to promote belief of cooperative decisions and actual cooperative behaviors in interaction. However, so far little is known about interpersonal brain synchronization between two people engaged in naturally occurring FF interactions. In this study, we combined an adapted ultimatum game with functional near-infrared spectroscopy (fNIRS) hyperscanning to investigate how FF interaction impacts interpersonal brain synchronization during economic exchange. Pairs of strangers interacted repeatedly either FF or face-blocked (FB), while their activation was simultaneously measured in the right temporo-parietal junction (rTPJ) and the control region, right dorsolateral prefrontal cortex (rDLPFC). Behaviorally, FF interactions increased shared intentionality between strangers, leading more positive belief of cooperative decisions and more actual gains in the game. FNIRS results indicated increased interpersonal brain synchronizations during FF interactions in rTPJ (but not in rDLPFC) with greater shared intentionality between partners. These results highlighted the importance of rTPJ in collaborative social interactions during FF economic exchange and warrant future research that combines FF interactions with fNIRS hyperscanning to study social brain disorders such as autism. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  16. The inferior parietal lobule and recognition memory : expectancy violation or successful retrieval?

    OpenAIRE

    O'Connor, Akira R.; Han, Sanghoon; Dobbins, Ian G.

    2010-01-01

    Functional neuroimaging studies of episodic recognition demonstrate an increased lateral parietal response for studied versus new materials, often termed a retrieval success effect. Using a novel memory analog of attentional cueing, we manipulated the correspondence between anticipated and actual recognition evidence by presenting valid or invalid anticipatory cues (e. g., "likely old") before recognition judgments. Although a superior parietal region demonstrated the retrieval success patter...

  17. Normal and abnormal growth plate

    International Nuclear Information System (INIS)

    Kumar, R.; Madewell, J.E.; Swischuk, L.E.

    1987-01-01

    Skeletal growth is a dynamic process. A knowledge of the structure and function of the normal growth plate is essential in order to understand the pathophysiology of abnormal skeletal growth in various diseases. In this well-illustrated article, the authors provide a radiographic classification of abnormal growth plates and discuss mechanisms that lead to growth plate abnormalities

  18. Word Recognition in Auditory Cortex

    Science.gov (United States)

    DeWitt, Iain D. J.

    2013-01-01

    Although spoken word recognition is more fundamental to human communication than text recognition, knowledge of word-processing in auditory cortex is comparatively impoverished. This dissertation synthesizes current models of auditory cortex, models of cortical pattern recognition, models of single-word reading, results in phonetics and results in…

  19. [Penile congenital abnormalities].

    Science.gov (United States)

    Boillot, B; Teklali, Y; Moog, R; Droupy, S

    2013-07-01

    Congenital abnormalities of the penis are usually diagnosed at birth and pose aesthetic and functional problems sometimes requiring surgical management. A literature review was conducted on Medline considering the articles listed until January 2012. Hypospadias is the most common malformation (1 in 250 boys. Familial forms: 7%). The causes remain hypothetical but the doubling of the incidence in 30 years could be linked to fetal exposure to endocrine disruptors "estrogen-like" used in the food industry in particular. Surgical treatment is usually intended to improve the aesthetic appearance but sometimes, in case of significant curvature or posterior meatus, necessary for normal sexual life and fertility. Other malformations (epispades, buried penis, transpositions, twists and preputial abnormalities) as well as management for functional or aesthetic consequences of these malformations in adulthood require complex surgical care in a specialized environment. The improvement of surgical techniques and pediatric anesthesia allows an early and effective specialized surgical approach of penile malformations. Management of sequelae in adulthood must be discussed and requires experience of surgical techniques on pediatric and adult penis. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  20. Visuo-spatial construction in patients with frontal and parietal lobe lesions

    Directory of Open Access Journals (Sweden)

    Himani Kashyap

    2011-04-01

    Full Text Available Visuospatial construction, traditionally viewed as a putative parietal function, also requires sustained attention, planning, organization strategies and error correction, and hence frontal lobe mediation. The relative contributions of the frontal and parietal lobes are poorly understood. To examine the contributions of parietal, frontal lobes, as well as right and left cerebral hemispheres to visuospatial construction. The Stick Construction Test for two-dimensional construction and the Block Construction Test for three-dimensional construction were administered pre-surgically to patients with lesions in the parietal lobe (n =9 and the frontal lobe (n=11, along with normal control subjects (n =20 matched to the patients on age (+/- 3 years, gender, education (+/- 3 years and handedness. The patients were significantly slower than the controls on both two-dimensional and three-dimensional tests. Patients with parietal lesions were slower than those with frontal lesions on the test of three-dimensional construction. Within each lobe patients with right and left sided lesions did not differ significantly. It appears that tests of three-dimensional construction might be most sensitive to visuospatial construction deficits. Visuospatial construction involves the mediation of both frontal and parietal lobes. The function does not appear to be lateralized. The networks arising from the parieto-occipital areas and projecting to the frontal cortices (e.g., occipito-frontal fasciculus may be the basis of the mediation of both lobes in visuospatial construction. The present findings need replication from studies with larger sample sizes.

  1. Patterns of morphological integration between parietal and temporal areas in the human skull.

    Science.gov (United States)

    Bruner, Emiliano; Pereira-Pedro, Ana Sofia; Bastir, Markus

    2017-10-01

    Modern humans have evolved bulging parietal areas and large, projecting temporal lobes. Both changes, largely due to a longitudinal expansion of these cranial and cerebral elements, were hypothesized to be the result of brain evolution and cognitive variations. Nonetheless, the independence of these two morphological characters has not been evaluated. Because of structural and functional integration among cranial elements, changes in the position of the temporal poles can be a secondary consequence of parietal bulging and reorientation of the head axis. In this study, we use geometric morphometrics to test the correlation between parietal shape and the morphology of the endocranial base in a sample of adult modern humans. Our results suggest that parietal proportions show no correlation with the relative position of the temporal poles within the spatial organization of the endocranial base. The vault and endocranial base are likely to be involved in distinct morphogenetic processes, with scarce or no integration between these two districts. Therefore, the current evidence rejects the hypothesis of reciprocal morphological influences between parietal and temporal morphology, suggesting that evolutionary spatial changes in these two areas may have been independent. However, parietal bulging exerts a visible effect on the rotation of the cranial base, influencing head position and orientation. This change can have had a major relevance in the reorganization of the head functional axis. © 2017 Wiley Periodicals, Inc.

  2. Brain activity dynamics in human parietal regions during spontaneous switches in bistable perception.

    Science.gov (United States)

    Megumi, Fukuda; Bahrami, Bahador; Kanai, Ryota; Rees, Geraint

    2015-02-15

    The neural mechanisms underlying conscious visual perception have been extensively investigated using bistable perception paradigms. Previous functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) studies suggest that the right anterior superior parietal (r-aSPL) and the right posterior superior parietal lobule (r-pSPL) have opposite roles in triggering perceptual reversals. It has been proposed that these two areas are part of a hierarchical network whose dynamics determine perceptual switches. However, how these two parietal regions interact with each other and with the rest of the brain during bistable perception is not known. Here, we investigated such a model by recording brain activity using fMRI while participants viewed a bistable structure-from-motion stimulus. Using dynamic causal modeling (DCM), we found that resolving such perceptual ambiguity was specifically associated with reciprocal interactions between these parietal regions and V5/MT. Strikingly, the strength of bottom-up coupling between V5/MT to r-pSPL and from r-pSPL to r-aSPL predicted individual mean dominance duration. Our findings are consistent with a hierarchical predictive coding model of parietal involvement in bistable perception and suggest that visual information processing underlying spontaneous perceptual switches can be described as changes in connectivity strength between parietal and visual cortical regions. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Neural mechanisms of oculomotor abnormalities in the infantile strabismus syndrome.

    Science.gov (United States)

    Walton, Mark M G; Pallus, Adam; Fleuriet, Jérome; Mustari, Michael J; Tarczy-Hornoch, Kristina

    2017-07-01

    Infantile strabismus is characterized by numerous visual and oculomotor abnormalities. Recently nonhuman primate models of infantile strabismus have been established, with characteristics that closely match those observed in human patients. This has made it possible to study the neural basis for visual and oculomotor symptoms in infantile strabismus. In this review, we consider the available evidence for neural abnormalities in structures related to oculomotor pathways ranging from visual cortex to oculomotor nuclei. These studies provide compelling evidence that a disturbance of binocular vision during a sensitive period early in life, whatever the cause, results in a cascade of abnormalities through numerous brain areas involved in visual functions and eye movements. Copyright © 2017 the American Physiological Society.

  4. The left visual-field advantage in rapid visual presentation is amplified rather than reduced by posterior-parietal rTMS

    DEFF Research Database (Denmark)

    Verleger, Rolf; Möller, Friderike; Kuniecki, Michal

    2010-01-01

    ) either as effective or as sham stimulation. In two experiments, either one of these two factors, hemisphere and effectiveness of rTMS, was varied within or between participants. Again, T2 was much better identified in the left than in the right visual field. This advantage of the left visual field......In the present task, series of visual stimuli are rapidly presented left and right, containing two target stimuli, T1 and T2. In previous studies, T2 was better identified in the left than in the right visual field. This advantage of the left visual field might reflect dominance exerted...... by the right over the left hemisphere. If so, then repetitive transcranial magnetic stimulation (rTMS) to the right parietal cortex might release the left hemisphere from right-hemispheric control, thereby improving T2 identification in the right visual field. Alternatively or additionally, the asymmetry in T2...

  5. Early sensitivity of left perisylvian cortex to relationality in nouns and verbs.

    Science.gov (United States)

    Williams, Adina; Reddigari, Samir; Pylkkänen, Liina

    2017-06-01

    The ability to track the relationality of concepts, i.e., their capacity to encode a relationship between entities, is one of the core semantic abilities humans possess. In language processing, we systematically leverage this ability when computing verbal argument structure, in order to link participants to the events they participate in. Previous work has converged on a large region of left posterior perisylvian cortex as a locus for such processing, but the wide range of experimental stimuli and manipulations has yielded an unclear picture of the region's exact role(s). Importantly, there is a tendency for effects of relationality in single-word studies to localize to posterior temporo-parietal cortex, while argument structure effects in sentences appear in left superior temporal cortex. To characterize these sensitivities, we designed two MEG experiments that cross the factors relationality and eventivity. The first used minimal noun phrases and tested for an effect of semantic composition, while the second employed full sentences and a manipulation of grammatical category. The former identified a region of the left inferior parietal lobe sensitive to relationality, but not eventivity or combination, beginning at 170ms. The latter revealed a similarly-timed effect of relationality in left mid-superior temporal cortex, independent of eventivity and category. The results suggest that i) multiple sub-regions of perisylvian cortex are sensitive to the relationality carried by concepts even in the absence of arguments, ii) linguistic context modulates the locus of this sensitivity, consistent with prior studies, and iii) relationality information is accessed early - before 200ms - regardless of the concept's event status or syntactic category. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Altered SPECT 123I-iomazenil Binding in the Cingulate Cortex of Children with Anorexia Nervosa

    Science.gov (United States)

    Nagamitsu, Shinichiro; Sakurai, Rieko; Matsuoka, Michiko; Chiba, Hiromi; Ozono, Shuichi; Tanigawa, Hitoshi; Yamashita, Yushiro; Kaida, Hayato; Ishibashi, Masatoshi; Kakuma, Tatsuki; Croarkin, Paul E.; Matsuishi, Toyojiro

    2016-01-01

    Several lines of evidence suggest that anxiety plays a key role in the development and maintenance of anorexia nervosa (AN) in children. The purpose of this study was to examine cortical GABA(A)-benzodiazepine receptor binding before and after treatment in children beginning intensive AN treatment. Brain single-photon emission computed tomography (SPECT) measurements using 123I-iomazenil, which binds to GABA(A)-benzodiazepine receptors, was performed in 26 participants with AN who were enrolled in a multimodal treatment program. Sixteen of the 26 participants underwent a repeat SPECT scan immediately before discharge at conclusion of the intensive treatment program. Eating behavior and mood disturbances were assessed using Eating Attitudes Test with 26 items (EAT-26) and the short form of the Profile of Mood States (POMS). Clinical outcome scores were evaluated after a 1-year period. We examined association between relative iomazenil-binding activity in cortical regions of interest and psychometric profiles and determined which psychometric profiles show interaction effects with brain regions. Further, we determined if binding activity could predict clinical outcome and treatment changes. Higher EAT-26 scores were significantly associated with lower iomazenil-binding activity in the anterior and posterior cingulate cortex. Higher POMS subscale scores were significantly associated with lower iomazenil-binding activity in the left frontal, parietal cortex, and posterior cingulate cortex (PCC). “Depression–Dejection” and “Confusion” POMS subscale scores, and total POMS score showed interaction effects with brain regions in iomazenil-binding activity. Decreased binding in the anterior cingulate cortex and left parietal cortex was associated with poor clinical outcomes. Relative binding increases throughout the PCC and occipital gyrus were observed after weight gain in children with AN. These findings suggest that cortical GABAergic receptor binding is altered

  7. The roles of superficial amygdala and auditory cortex in music-evoked fear and joy.

    Science.gov (United States)

    Koelsch, Stefan; Skouras, Stavros; Fritz, Thomas; Herrera, Perfecto; Bonhage, Corinna; Küssner, Mats B; Jacobs, Arthur M

    2013-11-01

    This study investigates neural correlates of music-evoked fear and joy with fMRI. Studies on neural correlates of music-evoked fear are scant, and there are only a few studies on neural correlates of joy in general. Eighteen individuals listened to excerpts of fear-evoking, joy-evoking, as well as neutral music and rated their own emotional state in terms of valence, arousal, fear, and joy. Results show that BOLD signal intensity increased during joy, and decreased during fear (compared to the neutral condition) in bilateral auditory cortex (AC) and bilateral superficial amygdala (SF). In the right primary somatosensory cortex (area 3b) BOLD signals increased during exposure to fear-evoking music. While emotion-specific activity in AC increased with increasing duration of each trial, SF responded phasically in the beginning of the stimulus, and then SF activity declined. Psychophysiological Interaction (PPI) analysis revealed extensive emotion-specific functional connectivity of AC with insula, cingulate cortex, as well as with visual, and parietal attentional structures. These findings show that the auditory cortex functions as a central hub of an affective-attentional network that is more extensive than previously believed. PPI analyses also showed functional connectivity of SF with AC during the joy condition, taken to reflect that SF is sensitive to social signals with positive valence. During fear music, SF showed functional connectivity with visual cortex and area 7 of the superior parietal lobule, taken to reflect increased visual alertness and an involuntary shift of attention during the perception of auditory signals of danger. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Roentgenologic abnormalities in Down's syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Higuchi, Takehiko; Russell, W J; Komatsuda, Michio; Neriishi, Shotaro

    1968-07-25

    Roentgenograms of 28 patients with Down's syndrome were reviewed with emphasis on all previously reported abnormalities and any possible additional ones. Most of the abnormalities occurred with the same frequency as previously reported, but some less frequently reported findings were also seen. One abnormal vertebral measurement found in this series may be an additional stigma of Down's syndrome. All of the 27 cases studied cytogenetically had chromosomal abnormalities consistent with this disease. This study emphasizes the need for roentgenologic norms for the Japanese, and the desirability of combining chromosome studies with roentgenological abnormalities and clinical observations in diagnosing Down's syndrome. 19 references, 2 figures, 5 tables.

  9. Structural brain abnormalities in Cushing's syndrome.

    Science.gov (United States)

    Bauduin, Stephanie E E C; van der Wee, Nic J A; van der Werff, Steven J A

    2018-05-08

    Alongside various physical symptoms, patients with Cushing's disease and Cushing's syndrome display a wide variety of neuropsychiatric and cognitive symptoms, which are indicative of involvement of the central nervous system. The aim of this review is to provide an overview of the structural brain abnormalities that are associated with Cushing's disease and Cushing's syndrome and their relation to behavioral and cognitive symptomatology. In this review, we discuss the gray matter structural abnormalities found in patients with active Cushing's disease and Cushing's syndrome, the reversibility and persistence of these changes and the white matter structural changes related to Cushing's syndrome. Recent findings are of particular interest because they provide more detailed information on localization of the structural changes as well as possible insights into the underlying biological processes. Active Cushing's disease and Cushing's syndrome is related to volume reductions of the hippocampus and in a prefrontal region involving the anterior cingulate cortex (ACC) and medial frontal gyrus (MFG). Whilst there are indications that the reductions in hippocampal volume are partially reversible, the changes in the ACC and MFG appear to be more persistent. In contrast to the volumetric findings, changes in white matter connectivity are typically widespread involving multiple tracts.

  10. Adams Oliver syndrome: Description of a new phenotype with cerebellar abnormalities in a family

    International Nuclear Information System (INIS)

    D’Amico, Alessandra; Melis, Daniela; D’Arco, Felice; Di Paolo, Nilde; Carotenuto, Barbara; D’Anna, Gennaro; Russo, Carmela; Boemio, Pasquale; Brunetti, Arturo

    2013-01-01

    To describe cerebellar abnormalities in a family composed by a father and two affected sibs with Adams Oliver syndrome (AOS) (OMIM 100300). Brain MRI and MR angiography were performed at 1.5T. The siblings presented cerebellar cortex dysplasia characterized by the presence of cysts. Abnormalities of CNS are an unusual manifestation of AOS. To our knowledge, this is the first report of cerebellar cortical dysplasia in a family with AOS

  11. Abnormalities of cortical structures in adolescent-onset conduct disorder.

    Science.gov (United States)

    Jiang, Y; Guo, X; Zhang, J; Gao, J; Wang, X; Situ, W; Yi, J; Zhang, X; Zhu, X; Yao, S; Huang, B

    2015-12-01

    Converging evidence has revealed both functional and structural abnormalities in adolescents with early-onset conduct disorder (EO-CD). The neurological abnormalities underlying EO-CD may be different from that of adolescent-onset conduct disorder (AO-CD) patients. However, the cortical structure in AO-CD patients remains largely unknown. The aim of the present study was to investigate the cortical alterations in AO-CD patients. We investigated T1-weighted brain images from AO-CD patients and age-, gender- and intelligence quotient-matched controls. Cortical structures including thickness, folding and surface area were measured using the surface-based morphometric method. Furthermore, we assessed impulsivity and antisocial symptoms using the Barratt Impulsiveness Scale (BIS) and the Antisocial Process Screening Device (APSD). Compared with the controls, we found significant cortical thinning in the paralimbic system in AO-CD patients. For the first time, we observed cortical thinning in the precuneus/posterior cingulate cortex (PCC) in AO-CD patients which has not been reported in EO-CD patients. Prominent folding abnormalities were found in the paralimbic structures and frontal cortex while diminished surface areas were shown in the precentral and inferior temporal cortex. Furthermore, cortical thickness of the paralimbic structures was found to be negatively correlated with impulsivity and antisocial behaviors measured by the BIS and APSD, respectively. The present study indicates that AO-CD is characterized by cortical structural abnormalities in the paralimbic system, and, in particular, we highlight the potential role of deficient structures including the precuneus and PCC in the etiology of AO-CD.

  12. A Rare Stapes Abnormality

    Directory of Open Access Journals (Sweden)

    Hala Kanona

    2015-01-01

    Full Text Available The aim of this study is to increase awareness of rare presentations, diagnostic difficulties alongside management of conductive hearing loss and ossicular abnormalities. We report the case of a 13-year-old female reporting progressive left-sided hearing loss and high resolution computed tomography was initially reported as normal. Exploratory tympanotomy revealed an absent stapedius tendon and lack of connection between the stapes superstructure and footplate. The footplate was fixed. Stapedotomy and stapes prosthesis insertion resulted in closure of the air-bone gap by 50 dB. A review of world literature was performed using MedLine. Middle ear ossicular discontinuity can result in significant conductive hearing loss. This can be managed effectively with surgery to help restore hearing. However, some patients may not be suitable or decline surgical intervention and can be managed safely conservatively.

  13. Listen, learn, like! Dorsolateral prefrontal cortex involved in the mere exposure effect in music

    DEFF Research Database (Denmark)

    Green, Anders Christian; Bærentsen, Klaus B.; Stødkilde-Jørgensen, Hans

    2012-01-01

    , participants rated liking for each melody and, later, their recognition of them. Participants showed learning effects, better recognising melodies heard more often. Melodies heard most often were most liked, consistent with the mere exposure effect. We found neural activations as a function of previous...... exposure in bilateral dorsolateral prefrontal and inferior parietal cortex, probably reflecting retrieval and working memory-related processes. This was despite the fact that the task during scanning was to judge liking, not recognition, thus suggesting that appreciation of music relies strongly on memory...

  14. Semantic strategy training increases memory performance and brain activity in patients with prefrontal cortex lesions.

    Science.gov (United States)

    Miotto, Eliane C; Savage, Cary R; Evans, Jonathan J; Wilson, Barbara A; Martin, Maria G M; Balardin, Joana B; Barros, Fabio G; Garrido, Griselda; Teixeira, Manoel J; Amaro Junior, Edson

    2013-03-01

    Memory deficit is a frequent cognitive disorder following acquired prefrontal cortex lesions. In the present study, we investigated the brain correlates of a short semantic strategy training and memory performance of patients with distinct prefrontal cortex lesions using fMRI and cognitive tests. Twenty-one adult patients with post-acute prefrontal cortex (PFC) lesions, twelve with left dorsolateral PFC (LPFC) and nine with bilateral orbitofrontal cortex (BOFC) were assessed before and after a short cognitive semantic training using a verbal memory encoding paradigm during scanning and neuropsychological tests outside the scanner. After the semantic strategy training both groups of patients showed significant behavioral improvement in verbal memory recall and use of semantic strategies. In the LPFC group, greater activity in left inferior and medial frontal gyrus, precentral gyrus and insula was found after training. For the BOFC group, a greater activation was found in the left parietal cortex, right cingulated and precuneus after training. The activation of these specific areas in the memory and executive networks following cognitive training was associated to compensatory brain mechanisms and application of the semantic strategy. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Lesions to polar/orbital prefrontal cortex selectively impair reasoning about emotional material.

    Science.gov (United States)

    Goel, Vinod; Lam, Elaine; Smith, Kathleen W; Goel, Amit; Raymont, Vanessa; Krueger, Frank; Grafman, Jordan

    2017-05-01

    While it is widely accepted that lesions to orbital prefrontal cortex lead to emotion related disruptions and poor decision-making, there is very little patient data on this issue involving actual logical reasoning tasks. We tested patients with circumscribed, focal lesions largely confined to polar/orbital prefrontal cortex (BA 10 & 11) (N=17) on logical reasoning tasks involving neutral and emotional content, and compared their performance to that of an age and education-matched normal control group (N=22) and a posterior lesion control group (N=24). Our results revealed a significant group by content interaction driven by a selective impairment in the polar/orbital prefrontal cortex group compared to healthy normal controls and to the parietal patient group, in the emotional content reasoning trials. Subsequent analyses of congruent and incongruent reasoning trials indicated that this impairment was driven by the poor performance of patients with polar/orbital lesions in the incongruent trials. We conclude that the polar/orbital prefrontal cortex plays a critical role in filtering emotionally charged content from the material before it is passed on to the reasoning system in lateral/dorsal regions of prefrontal cortex. Where unfiltered content is passed to the reasoning engine, either as a result of pathology (as in the case of our patients) or as a result of individual differences, reasoning performance suffers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Dissociation of object and spatial visual processing pathways in human extrastriate cortex

    Energy Technology Data Exchange (ETDEWEB)

    Haxby, J.V.; Grady, C.L.; Horwitz, B.; Ungerleider, L.G.; Mishkin, M.; Carson, R.E.; Herscovitch, P.; Schapiro, M.B.; Rapoport, S.I. (National Institutes of Health, Bethesda, MD (USA))

    1991-03-01

    The existence and neuroanatomical locations of separate extrastriate visual pathways for object recognition and spatial localization were investigated in healthy young men. Regional cerebral blood flow was measured by positron emission tomography and bolus injections of H2(15)O, while subjects performed face matching, dot-location matching, or sensorimotor control tasks. Both visual matching tasks activated lateral occipital cortex. Face discrimination alone activated a region of occipitotemporal cortex that was anterior and inferior to the occipital area activated by both tasks. The spatial location task alone activated a region of lateral superior parietal cortex. Perisylvian and anterior temporal cortices were not activated by either task. These results demonstrate the existence of three functionally dissociable regions of human visual extrastriate cortex. The ventral and dorsal locations of the regions specialized for object recognition and spatial localization, respectively, suggest some homology between human and nonhuman primate extrastriate cortex, with displacement in human brain, possibly related to the evolution of phylogenetically newer cortical areas.

  17. FGF-2 induces behavioral recovery after early adolescent injury to the motor cortex of rats.

    Science.gov (United States)

    Nemati, Farshad; Kolb, Bryan

    2011-11-20

    Motor cortex injuries in adulthood lead to poor performance in behavioral tasks sensitive to limb movements in the rat. We have shown previously that motor cortex injury on day 10 or day 55 allow significant spontaneous recovery but not injury in early adolescence (postnatal day 35 "P35"). Previous studies have indicated that injection of basic fibroblast growth factor (FGF-2) enhances behavioral recovery after neonatal cortical injury but such effect has not been studied following motor cortex lesions in early adolescence. The present study undertook to investigate the possibility of such behavioral recovery. Rats with unilateral motor cortex lesions were assigned to two groups in which they received FGF-2 or bovine serum albumin (BSA) and were tested in a number of behavioral tests (postural asymmetry, skilled reaching, sunflower seed manipulation, forepaw inhibition in swimming). Golgi-Cox analysis was used to examine the dendritic structure of pyramidal cells in the animals' parietal (layer III) and forelimb (layer V) area of the cortex. The results indicated that rats injected with FGF-2 (but not BSA) showed significant behavioral recovery that was associated with increased dendritic length and spine density. The present study suggests a role for FGF-2 in the recovery of function following injury during early adolescence. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Cerebral cortex modulation of pain

    Institute of Scientific and Technical Information of China (English)

    Yu-feng XIE; Fu-quan HUO; Jing-shi TANG

    2009-01-01

    Pain is a complex experience encompassing sensory-discriminative, affective-motivational and cognitiv e-emotional com-ponents mediated by different mechanisms. Contrary to the traditional view that the cerebral cortex is not involved in pain perception, an extensive cortical network associated with pain processing has been revealed using multiple methods over the past decades. This network consistently includes, at least, the anterior cingulate cortex, the agranular insular cortex, the primary (SⅠ) and secondary somatosensory (SⅡ) cortices, the ventrolateral orbital cortex and the motor cortex. These corti-cal structures constitute the medial and lateral pain systems, the nucleus submedius-ventrolateral orbital cortex-periaque-ductal gray system and motor cortex system, respectively. Multiple neurotransmitters, including opioid, glutamate, GABA and dopamine, are involved in the modulation of pain by these cortical structures. In addition, glial cells may also be in-volved in cortical modulation of pain and serve as one target for pain management research. This review discusses recent studies of pain modulation by these cerebral cortical structures in animals and human.

  19. Sex-dependent age modulation of frontostriatal and temporo-parietal activation during cognitive control.

    Science.gov (United States)

    Christakou, Anastasia; Halari, Rozmin; Smith, Anna B; Ifkovits, Eve; Brammer, Mick; Rubia, Katya

    2009-10-15

    Developmental functional imaging studies of cognitive control show progressive age-related increase in task-relevant fronto-striatal activation in male development from childhood to adulthood. Little is known, however, about how gender affects this functional development. In this study, we used event related functional magnetic resonance imaging to examine effects of sex, age, and their interaction on brain activation during attentional switching and interference inhibition, in 63 male and female adolescents and adults, aged 13 to 38. Linear age correlations were observed across all subjects in task-specific frontal, striatal and temporo-parietal activation. Gender analysis revealed increased activation in females relative to males in fronto-striatal areas during the Switch task, and laterality effects in the Simon task, with females showing increased left inferior prefrontal and temporal activation, and males showing increased right inferior prefrontal and parietal activation. Increased prefrontal activation clusters in females and increased parietal activation clusters in males furthermore overlapped with clusters that were age-correlated across the whole group, potentially reflecting more mature prefrontal brain activation patterns for females, and more mature parietal activation patterns for males. Gender by age interactions further supported this dissociation, revealing exclusive female-specific age correlations in inferior and medial prefrontal brain regions during both tasks, and exclusive male-specific age correlations in superior parietal (Switch task) and temporal regions (Simon task). These findings show increased recruitment of age-correlated prefrontal activation in females, and of age-correlated parietal activation in males, during tasks of cognitive control. Gender differences in frontal and parietal recruitment may thus be related to gender differences in the neurofunctional maturation of these brain regions.

  20. Pure apraxia of speech due to infarct in premotor cortex.

    Science.gov (United States)

    Patira, Riddhi; Ciniglia, Lauren; Calvert, Timothy; Altschuler, Eric L

    Apraxia of speech (AOS) is now recognized as an articulation disorder distinct from dysarthria and aphasia. Various lesions have been associated with AOS in studies that are limited in precise localization due to variability in size and type of pathology. We present a case of pure AOS in setting of an acute stroke to localize more precisely than ever before the brain area responsible for AOS, dorsal premotor cortex (dPMC). The dPMC is in unique position to plan and coordinate speech production by virtue of its connection with nearby motor cortex harboring corticobulbar tract, supplementary motor area, inferior frontal operculum, and temporo-parietal area via the dorsal stream of dual-stream model of speech processing. The role of dPMC is further supported as part of dorsal stream in the dual-stream model of speech processing as well as controller in the hierarchical state feedback control model. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  1. Neurodevelopmental origins of abnormal cortical morphology in dissociative identity disorder.

    Science.gov (United States)

    Reinders, A A T S; Chalavi, S; Schlumpf, Y R; Vissia, E M; Nijenhuis, E R S; Jäncke, L; Veltman, D J; Ecker, C

    2018-02-01

    To examine the two constitutes of cortical volume (CV), that is, cortical thickness (CT) and surface area (SA), in individuals with dissociative identity disorder (DID) with the view of gaining important novel insights into the underlying neurobiological mechanisms mediating DID. This study included 32 female patients with DID and 43 matched healthy controls. Between-group differences in CV, thickness, and SA, the degree of spatial overlap between differences in CT and SA, and their relative contribution to differences in regional CV were assessed using a novel spatially unbiased vertex-wise approach. Whole-brain correlation analyses were performed between measures of cortical anatomy and dissociative symptoms and traumatization. Individuals with DID differed from controls in CV, CT, and SA, with significantly decreased CT in the insula, anterior cingulate, and parietal regions and reduced cortical SA in temporal and orbitofrontal cortices. Abnormalities in CT and SA shared only about 3% of all significantly different cerebral surface locations and involved distinct contributions to the abnormality of CV in DID. Significant negative associations between abnormal brain morphology (SA and CV) and dissociative symptoms and early childhood traumatization (0 and 3 years of age) were found. In DID, neuroanatomical areas with decreased CT and SA are in different locations in the brain. As CT and SA have distinct genetic and developmental origins, our findings may indicate that different neurobiological mechanisms and environmental factors impact on cortical morphology in DID, such as early childhood traumatization. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. A 3 T event-related functional magnetic resonance imaging (fMRI) study of primary and secondary gustatory cortex localization using natural tastants

    International Nuclear Information System (INIS)

    Smits, Marion; Peeters, Ronald R.; Hecke, Paul van; Sunaert, Stefan

    2007-01-01

    It is known that taste is centrally represented in the insula, frontal and parietal operculum, as well as in the orbitofrontal cortex (secondary gustatory cortex). In functional MRI (fMRI) experiments activation in the insula has been confirmed, but activation in the orbitofrontal cortex is only infrequently found, especially at higher field strengths (3 T). Due to large susceptibility artefacts, the orbitofrontal cortex is a difficult region to examine with fMRI. Our aim was to localize taste in the human cortex at 3 T, specifically in the orbitofrontal cortex as well as in the primary gustatory cortex. Event-related fMRI was performed at 3 T in seven healthy volunteers. Taste stimuli consisted of lemon juice and chocolate. To visualize activation in the orbitofrontal cortex a dedicated 3D SENSE EPI fMRI sequence was used, in addition to a 2D SENSE EPI fMRI sequence for imaging the entire brain. Data were analyzed using a perception-based model. The dedicated 3D SENSE EPI sequence successfully reduced susceptibility artefacts in the orbitofrontal area. Significant taste-related activation was found in the orbitofrontal and insular cortices. fMRI of the orbitofrontal cortex is feasible at 3 T, using a dedicated sequence. Our results corroborate findings from previous studies. (orig.)

  3. A 3 T event-related functional magnetic resonance imaging (fMRI) study of primary and secondary gustatory cortex localization using natural tastants

    Energy Technology Data Exchange (ETDEWEB)

    Smits, Marion [Erasmus MC, University Medical Center Rotterdam, Department of Radiology, P.O. Box 2040, CA Rotterdam (Netherlands); K.U.Leuven, Department of Radiology, University Hospitals, Leuven (Belgium); Peeters, Ronald R.; Hecke, Paul van; Sunaert, Stefan [K.U.Leuven, Department of Radiology, University Hospitals, Leuven (Belgium)

    2007-01-15

    It is known that taste is centrally represented in the insula, frontal and parietal operculum, as well as in the orbitofrontal cortex (secondary gustatory cortex). In functional MRI (fMRI) experiments activation in the insula has been confirmed, but activation in the orbitofrontal cortex is only infrequently found, especially at higher field strengths (3 T). Due to large susceptibility artefacts, the orbitofrontal cortex is a difficult region to examine with fMRI. Our aim was to localize taste in the human cortex at 3 T, specifically in the orbitofrontal cortex as well as in the primary gustatory cortex. Event-related fMRI was performed at 3 T in seven healthy volunteers. Taste stimuli consisted of lemon juice and chocolate. To visualize activation in the orbitofrontal cortex a dedicated 3D SENSE EPI fMRI sequence was used, in addition to a 2D SENSE EPI fMRI sequence for imaging the entire brain. Data were analyzed using a perception-based model. The dedicated 3D SENSE EPI sequence successfully reduced susceptibility artefacts in the orbitofrontal area. Significant taste-related activation was found in the orbitofrontal and insular cortices. fMRI of the orbitofrontal cortex is feasible at 3 T, using a dedicated sequence. Our results corroborate findings from previous studies. (orig.)

  4. A prospective study of diffusion weighted magnetic resonance imaging abnormalities in patients with cluster of seizures and status epilepticus.

    Science.gov (United States)

    Jabeen, S A; Cherukuri, Pavankumar; Mridula, Rukmini; Harshavardhana, K R; Gaddamanugu, Padmaja; Sarva, Sailaja; Meena, A K; Borgohain, Rupam; Jyotsna Rani, Y

    2017-04-01

    To study the frequency, imaging characteristics, and clinical predictors for development of periictal diffusion weighted MRI abnormalities. We prospectively analyzed electro clinical and imaging characteristic of adult patients with cluster of seizures or status epilepticus between November 2013 and November 2015, in whom the diffusion weighted imaging was done within 24h after the end of last seizure (clinical or electrographic). There were thirty patients who fulfilled the inclusion and exclusion criteria. Twenty patients (66%) had periictal MRI abnormalities. Nine patients (34%) did not have any MRI abnormality. All the patients with PMA had abnormalities on diffusion weighted imaging (DWI). Hippocampal abnormalities were seen in nine (53%), perisylvian in two (11.7%), thalamic in five (30%), splenium involvement in two (11.7%) and cortical involvement (temporo-occipital, parieto-occipital, temporo-parietal, fronto-parietal and fronto-temporal) in sixteen (94.1%) patients. Complete reversal of DWI changes was noted in sixteen (80%) patients and four (20%) patients showed partial resolution of MRI abnormalities. Mean duration of seizures was significantly higher among patients with PMA (59.11+20.97h) compared to those without MRI changes (27.33+9.33h) (pstatus epilepticus and were highly concordant with clinical semiology and EEG activity. Patients with longer duration of seizures/status were more likely to have PMA. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Abstract Representations of Object-Directed Action in the Left Inferior Parietal Lobule.

    Science.gov (United States)

    Chen, Quanjing; Garcea, Frank E; Jacobs, Robert A; Mahon, Bradford Z

    2018-06-01

    Prior neuroimaging and neuropsychological research indicates that the left inferior parietal lobule in the human brain is a critical substrate for representing object manipulation knowledge. In the present functional MRI study we used multivoxel pattern analyses to test whether action similarity among objects can be decoded in the inferior parietal lobule independent of the task applied to objects (identification or pantomime) and stimulus format in which stimuli are presented (pictures or printed words). Participants pantomimed the use of objects, cued by printed words, or identified pictures of objects. Classifiers were trained and tested across task (e.g., training data: pantomime; testing data: identification), stimulus format (e.g., training data: word format; testing format: picture) and specific objects (e.g., training data: scissors vs. corkscrew; testing data: pliers vs. screwdriver). The only brain region in which action relations among objects could be decoded across task, stimulus format and objects was the inferior parietal lobule. By contrast, medial aspects of the ventral surface of the left temporal lobe represented object function, albeit not at the same level of abstractness as actions in the inferior parietal lobule. These results suggest compulsory access to abstract action information in the inferior parietal lobe even when simply identifying objects.

  6. Maps of the Auditory Cortex.

    Science.gov (United States)

    Brewer, Alyssa A; Barton, Brian

    2016-07-08

    One of the fundamental properties of the mammalian brain is that sensory regions of cortex are formed of multiple, functionally specialized cortical field maps (CFMs). Each CFM comprises two orthogonal topographical representations, reflecting two essential aspects of sensory space. In auditory cortex, auditory field maps (AFMs) are defined by the combination of tonotopic gradients, representing the spectral aspects of sound (i.e., tones), with orthogonal periodotopic gradients, representing the temporal aspects of sound (i.e., period or temporal envelope). Converging evidence from cytoarchitectural and neuroimaging measurements underlies the definition of 11 AFMs across core and belt regions of human auditory cortex, with likely homology to those of macaque. On a macrostructural level, AFMs are grouped into cloverleaf clusters, an organizational structure also seen in visual cortex. Future research can now use these AFMs to investigate specific stages of auditory processing, key for understanding behaviors such as speech perception and multimodal sensory integration.

  7. Autoshaping of abnormal children.

    Science.gov (United States)

    Deckner, C W; Wilcox, L M; Maisto, S A; Blanton, R L

    1980-09-01

    Three experimentally naive abnormal children were exposed to a terminal operant contingency, i.e., reinforcement was delivered only if the children pressed a panel during intervals when it was lighted. Despite the absence of both successive approximation and manual shaping, it was found that each child began to respond discriminatively within a small number of trials. These data replicated previous animal studies concerned with the phenomena of autoshaping and signal-controlled responding. It was also found, however, that one type of autoshaping, the classical conditioning procedure, had a powerful suppressive effect on the discriminative responding. An experimental analysis that consisted procedure, had a powerful suppressive effect on discriminative responding. An experimental analysis that consisted of intrasubject reversal an multiple baseline designs established the internal validity of the findings. The finding of rapid acquisition of signal-controlled responding obtained with the initial procedure is suggessted to have practical significance. The disruptive effects of the classical form of autoshaping are discussed in terms of negative behavioral contrast.

  8. Communication and abnormal behaviour.

    Science.gov (United States)

    Crown, S

    1979-01-01

    In this paper the similarities between normal and abnormal behaviour are emphasized and selected aspects of communication, normal and aberrant, between persons are explored. Communication in a social system may be verbal or non-verbal: one person's actions cause a response in another person. This response may be cognitive, behavioural or physiological. Communication may be approached through the individual, the social situation or social interaction. Psychoanalysis approaches the individual in terms of the coded communications of psychoneurotic symptoms or psychotic behaviour; the humanist-existential approach is concerned more with emotional expression. Both approaches emphasize the development of individual identity. The interaction between persons and their social background is stressed. Relevant are sociological concepts such as illness behaviour, stigma, labelling, institutionalization and compliance. Two approaches to social interactions are considered: the gamesplaying metaphor, e.g. back pain as a psychosocial manipulation--the 'pain game'; and the 'spiral of reciprocal perspectives' which emphasizes the interactional complexities of social perceptions. Communicatory aspects of psychological treatments are noted: learning a particular metaphor such as 'resolution' of the problem (psychotherapy), learning more 'rewarding' behaviour (learning theory) or learning authenticity or self-actualization (humanist-existential).

  9. Abnormally dark or light skin

    Science.gov (United States)

    Hyperpigmentation; Hypopigmentation; Skin - abnormally light or dark ... Normal skin contains cells called melanocytes. These cells produce melanin , the substance that gives skin its color. Skin with ...

  10. Chemosensory Learning in the Cortex

    Directory of Open Access Journals (Sweden)

    Edmund eRolls

    2011-09-01

    Full Text Available Taste is a primary reinforcer. Olfactory-taste and visual-taste association learning takes place in the primate including human orbitofrontal cortex to build representations of flavour. Rapid reversal of this learning can occur using a rule-based learning system that can be reset when an expected taste or flavour reward is not obtained, that is by negative reward prediction error, to which a population of neurons in the orbitofrontal cortex responds. The representation in the orbitofrontal cortex but not the primary taste or olfactory cortex is of the reward value of the visual / olfactory / taste / input as shown by devaluation experiments in which food is fed to satiety, and by correlations with the activations with subjective pleasantness ratings in humans. Sensory-specific satiety for taste, olfactory, visual, and oral somatosensory inputs produced by feeding a particular food to satiety are implemented it is proposed by medium-term synaptic adaptation in the orbitofrontal cortex. Cognitive factors, including word-level descriptions, modulate the representation of the reward value of food in the orbitofrontal cortex, and this effect is learned it is proposed by associative modification of top-down synapses onto neurons activated by bottom-up taste and olfactory inputs when both are active in the orbitofrontal cortex. A similar associative synaptic learning process is proposed to be part of the mechanism for the top-down attentional control to the reward value vs the sensory properties such as intensity of taste and olfactory inputs in the orbitofrontal cortex, as part of a biased activation theory of selective attention.

  11. Fatty acid composition of the postmortem prefrontal cortex of patients with schizophrenia, bipolar disorder, and major depressive disorder.

    Science.gov (United States)

    Hamazaki, Kei; Maekawa, Motoko; Toyota, Tomoko; Dean, Brian; Hamazaki, Tomohito; Yoshikawa, Takeo

    2015-06-30

    Postmortem brain studies have shown abnormal levels of n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid, in the frontal cortex (particularly the orbitofrontal cortex) of patients with depression, schizophrenia, or bipolar disorder. However, the results from regions in the frontal cortex other than the orbitofrontal cortex are inconsistent. In this study we investigated whether patients with schizophrenia, bipolar disorder, or major depressive disorder have abnormalities in PUFA levels in the prefrontal cortex [Brodmann area (BA) 8]. In postmortem studies, fatty acids in the phospholipids of the prefrontal cortex (BA8) were evaluated by thin layer chromatography and gas chromatography. Specimens were evaluated for patients with schizophrenia (n=15), bipolar disorder (n=15), or major depressive disorder (n=15) and compared with unaffected controls (n=15). In contrast to previous studies, we found no significant differences in the levels of PUFAs or other fatty acids in the prefrontal cortex (BA8) between patients and controls. Subanalysis by sex also showed no significant differences. No significant differences were found in any individual fatty acids between suicide and non-suicide cases. These psychiatric disorders might be characterized by very specific fatty acid compositions in certain areas of the brain, and BA8 might not be involved in abnormalities of PUFA metabolism. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Gray matter abnormalities in patients with narcissistic personality disorder.

    Science.gov (United States)

    Schulze, Lars; Dziobek, Isabel; Vater, Aline; Heekeren, Hauke R; Bajbouj, Malek; Renneberg, Babette; Heuser, Isabella; Roepke, Stefan

    2013-10-01

    Despite the relevance of narcissistic personality disorder (NPD) in clinical settings, there is currently no empirical data available regarding the neurobiological correlates of NPD. In the present stud