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

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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.

Anatomical substrates of the alerting, orienting and executive control components of attention: focus on the posterior parietal lobe.

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Xuntao Yin

Full Text Available Both neuropsychological and functional neuroimaging studies have identified that the posterior parietal lobe (PPL is critical for the attention function. However, the unique role of distinct parietal cortical subregions and their underlying white matter (WM remains in question. In this study, we collected both magnetic resonance imaging and diffusion tensor imaging (DTI data in normal participants, and evaluated their attention performance using attention network test (ANT, which could isolate three different attention components: alerting, orienting and executive control. Cortical thickness, surface area and DTI parameters were extracted from predefined PPL subregions and correlated with behavioural performance. Tract-based spatial statistics (TBSS was used for the voxel-wise statistical analysis. Results indicated structure-behaviour relationships on multiple levels. First, a link between the cortical thickness and WM integrity of the right inferior parietal regions and orienting performance was observed. Specifically, probabilistic tractography demonstrated that the integrity of WM connectivity between the bilateral inferior parietal lobules mediated the orienting performance. Second, the scores of executive control were significantly associated with the WM diffusion metrics of the right supramarginal gyrus. Finally, TBSS analysis revealed that alerting performance was significant correlated with the fractional anisotropy of local WM connecting the right thalamus and supplementary motor area. We conclude that distinct areas and features within PPL are associated with different components of attention. These findings could yield a more complete understanding of the nature of the PPL contribution to visuospatial attention.

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

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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

Changes in frontal lobe function before and after surgery in patients with unruptured intracranial aneurysm

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Ozaki, Saya; Kumon, Yoshiaki; Igase, Keiji; Watanabe, Hideaki; Ohnishi, Takanori

2008-01-01

We evaluated neuropsychological function in 18 patients with unruptured cerebral aneurysm who showed good postoperative outcomes. We paid particular attention to frontal lobe function. We also investigated relationships between cerebral blood flow (CBF) and frontal lobe function. Patients were examined using digit span, word fluency (WF), Stroop and trail-making tests to clarify frontal lobe function before and 1-2 months after surgery. We also used the mini-mental state examination (MMSE), Raven's colored progressive matrices (RCPM) and revised Wechsler adult intelligence scale (WAIS-R) to examine cognitive function. CBF was measured using 133 Xe-single photon emission computed tomography (SPECT) before and 1-2 months after surgery. Tests revealed that the patients' postoperative neuropsychological status was improved compared to the preoperative status for MMSE, RCPM and WAIS-R. Among the tests of frontal lobe function, WF results had deteriorated significantly after surgery. Resting CBF in the frontal lobe was significantly decreased. Regional CBF in the frontal lobe was decreased significantly in comparison with values in the parietal and temporal lobes in patients showing deterioration of WF. Deterioration of WF correlated with CBF changes in the frontal lobe. These results suggest that surgery for unruptured cerebral aneurysm exerts detrimental effects on frontal lobe function that may be related to CBF changes. (author)

Executive Functions in Healthy Older Adults Are Differentially Related to Macro- and Microstructural White Matter Characteristics of the Cerebral Lobes

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Sarah Hirsiger

2017-11-01

Full Text Available Aging is associated with microstructural white matter (WM changes. WM microstructural characteristics, measured with diffusion tensor imaging (DTI, are different in normal appearing white matter (NAWM and WM hyperintensities (WMH. It is largely unknown how the microstructural properties of WMH are associated with cognition and if there are regional effects for specific cognitive domains. We therefore examined within 200 healthy older participants (a differences in microstructural characteristics of NAWM and WMH per cerebral lobe; and (b the association of macrostructural (WMH volume and microstructural characteristics (within NAWM and WMH separately of each lobe with measures of executive function and processing speed. Multi-modal imaging (i.e., T1, DTI, and FLAIR was used to assess WM properties. The Stroop and the Trail Making Test were used to measure inhibition, task-switching (both components of executive function, and processing speed. We observed that age was associated with deterioration of white matter microstructure of the NAWM, most notably in the frontal lobe. Older participants had larger WMH volumes and lowest fractional anisotropy values within WMH were found in the frontal lobe. Task-switching was associated with cerebral NAWM volume and NAWM volume of all lobes. Processing speed was associated with total NAWM volume, and microstructural properties of parietal NAWM, the parietal WMH, and the temporal NAWM. Task-switching was related to microstructural properties of WMH of the frontal lobe and WMH volume of the parietal lobe. Our results confirm that executive functioning and processing speed are uniquely associated with macro- and microstructural properties of NAWM and WMH. We further demonstrate for the first time that these relationships differ by lobar region. This warrants the consideration of these distinct WM indices when investigating cognitive function.

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

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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

Short parietal lobe connections of the human and monkey brain

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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....

Abnormal activation of the occipital lobes during emotion picture processing in major depressive disorder patients

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Li, Jianying; Xu, Cheng; Cao, Xiaohua; Gao, Qiang; Wang, Yan; Wang, Yanfang; Peng, Juyi; Zhang, Kerang

2013-01-01

A large number of studies have demonstrated that depression patients have cognitive dysfunction. With recently developed brain functional imaging, studies have focused on changes in brain function to investigate cognitive changes. However, there is still controversy regarding abnormalities in brain functions or correlation between cognitive impairment and brain function changes. Thus, it is important to design an emotion-related task for research into brain function changes. We selected positive, neutral, and negative pictures from the International Affective Picture System. Patients with major depressive disorder were asked to judge emotion pictures. In addition, functional MRI was performed to synchronously record behavior data and imaging data. Results showed that the total correct rate for recognizing pictures was lower in patients compared with normal controls. Moreover, the consistency for recognizing pictures for depressed patients was worse than normal controls, and they frequently recognized positive pictures as negative pictures. The consistency for recognizing pictures was negatively correlated with the Hamilton Depression Rating Scale. Functional MRI suggested that the activation of some areas in the frontal lobe, temporal lobe, parietal lobe, limbic lobe, and cerebellum was enhanced, but that the activation of some areas in the frontal lobe, parietal lobe and occipital lobe was weakened while the patients were watching positive and neutral pictures compared with normal controls. The activation of some areas in the frontal lobe, temporal lobe, parietal lobe, and limbic lobe was enhanced, but the activation of some areas in the occipital lobe were weakened while the patients were watching the negative pictures compared with normal controls. These findings indicate that patients with major depressive disorder have negative cognitive disorder and extensive brain dysfunction. Thus, reduced activation of the occipital lobe may be an initiating factor for

Frontal lobe function in temporal lobe epilepsy

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Stretton, J.; Thompson, P.J.

2012-01-01

Summary Temporal lobe epilepsy (TLE) is typically associated with long-term memory dysfunction. The frontal lobes support high-level cognition comprising executive skills and working memory that is vital for daily life functioning. Deficits in these functions have been increasingly reported in TLE. Evidence from both the neuropsychological and neuroimaging literature suggests both executive function and working memory are compromised in the presence of TLE. In relation to executive impairment, particular focus has been paid to set shifting as measured by the Wisconsin Card Sorting Task. Other discrete executive functions such as decision-making and theory of mind also appear vulnerable but have received little attention. With regard to working memory, the medial temporal lobe structures appear have a more critical role, but with emerging evidence of hippocampal dependent and independent processes. The relative role of underlying pathology and seizure spread is likely to have considerable bearing upon the cognitive phenotype and trajectory in TLE. The identification of the nature of frontal lobe dysfunction in TLE thus has important clinical implications for prognosis and surgical management. Longitudinal neuropsychological and neuroimaging studies assessing frontal lobe function in TLE patients pre- and postoperatively will improve our understanding further. PMID:22100147

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

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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.

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

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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

Abstract Representations of Object-Directed Action in the Left Inferior Parietal Lobule.

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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.

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

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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.

Functional segregation and integration within fronto-parietal networks.

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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.

The frontal lobes and inhibitory function

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Konishi, Seiki

2011-01-01

Neuropsychological studies using traditional tasks of inhibitory functions, such as the Wisconsin card sorting test (WCST) and the Go/No-Go Task have revealed that the frontal lobe is responsible for several types of inhibitory functions. However, the detailed psychological nature of the inhibitory functions and the precise location of their critical foci within the frontal lobe remain to be investigated. Functional magnetic resonance imaging provides spatial and temporal resolution that allowed us to illuminate at least 4 frontal regions involved in inhibitory functions: the dorsolateral, ventrolateral, and rostral parts of the frontal lobe and the presupplementary motor area (preSMA). The ventrolateral part of the frontal lobe in the right hemisphere was activated during response inhibition. The preSMA in the left hemisphere was activated during inhibition of proactive interference immediately after the dimension changes of the WCST. The rostral part of the frontal lobe in the left hemisphere was activated during inhibition long after the dimension changes. The dorsolateral part of the frontal lobe in the left hemisphere was activated at the dimension changes in the first time, but not in the second time. These findings provide clues to our understanding of functional differentiation of inhibitory functions and their localization in the frontal lobe. (author)

Connectivity pattern differences bilaterally in the cerebellum posterior lobe in healthy subjects after normal sleep and sleep deprivation: a resting-state functional MRI study

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Liu XM

2015-05-01

Full Text Available Xuming Liu,1 Zhihan Yan,2 Tingyu Wang,1 Xiaokai Yang,1 Feng Feng,3 Luping Fan,1 Jian Jiang4 1Department of Radiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, 2Department of Radiology, The 2nd Affiliated Hospital of Wenzhou Medical University, Wenzhou, 3Peking Union Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 4Department of Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, People’s Republic of China Objective: The aim of this study was to use functional magnetic resonance imaging (fMRI technique to explore the resting-state functional connectivity (rsFC differences of the bilaterial cerebellum posterior lobe (CPL after normal sleep (NS and after sleep deprivation (SD. Methods: A total of 16 healthy subjects (eight males, eight females underwent an fMRI scan twice at random: once following NS and the other following 24 hours’ SD, with an interval of 1 month between the two scans. The fMRI scanning included resting state and acupuncture stimulation. The special activated regions located during the acupuncture stimulation were selected as regions of interest for rsFC analysis. Results: Bilateral CPLs were positively activated by acupuncture stimulation. In the NS group, the left CPL showed rsFC with the bilateral CPL, bilateral frontal lobe (BFL, left precuneus and right inferior parietal lobule, while the right CPL showed rsFC with the bilateral temporal lobe, right cerebellum anterior lobe, right CPL, left frontal lobe, left anterior cingulate, right posterior cingulate, and bilateral inferior parietal lobule. In the SD group, the left CPL showed rsFC with the left posterior cingulate gyrus bilateral CPL, left precuneus, left precentral gyrus, BFL, and the left parietal lobe, while the right CPL showed rsFC with bilateral cerebellum anterior lobe, bilateral CPL, left frontal lobe and left temporal lobe. Compared with the NS group, the

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.

Microsurgical anatomy of the central lobe.

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Frigeri, Thomas; Paglioli, Eliseu; de Oliveira, Evandro; Rhoton, Albert L

2015-03-01

The central lobe consists of the pre- and postcentral gyri on the lateral surface and the paracentral lobule on the medial surface and corresponds to the sensorimotor cortex. The objective of the present study was to define the neural features, craniometric relationships, arterial supply, and venous drainage of the central lobe. Cadaveric hemispheres dissected using microsurgical techniques provided the material for this study. The coronal suture is closer to the precentral gyrus and central sulcus at its lower rather than at its upper end, but they are closest at a point near where the superior temporal line crosses the coronal suture. The arterial supply of the lower two-thirds of the lateral surface of the central lobe was from the central, precentral, and anterior parietal branches that arose predominantly from the superior trunk of the middle cerebral artery. The medial surface and the superior third of the lateral surface were supplied by the posterior interior frontal, paracentral, and superior parietal branches of the pericallosal and callosomarginal arteries. The venous drainage of the superior two-thirds of the lateral surface and the central lobe on the medial surface was predominantly through the superior sagittal sinus, and the inferior third of the lateral surface was predominantly through the superficial sylvian veins to the sphenoparietal sinus or the vein of Labbé to the transverse sinus. The pre- and postcentral gyri and paracentral lobule have a morphological and functional anatomy that differentiates them from the remainder of their respective lobes and are considered by many as a single lobe. An understanding of the anatomical relationships of the central lobe can be useful in preoperative planning and in establishing reliable intraoperative landmarks.

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.

Cognitive dysfunctions in occipital lobe epilepsy compared to temporal lobe epilepsy.

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Santangelo, Gabriella; Trojano, Luigi; Vitale, Carmine; Improta, Ilaria; Alineri, Irma; Meo, Roberta; Bilo, Leonilda

2017-06-01

To compare cognitive profiles of occipital lobe epilepsy (OLE) and temporal lobe epilepsy (TLE) and to investigate whether impairment of visuospatial functions is a specific deficit of OLE. Eighteen patients with OLE, 18 patients with TLE, and 18 controls underwent a neuropsychological battery assessing memory, visuospatial functions, and frontal/executive functions. Multivariate analysis evidenced poorer performance of patients with TLE and patients with OLE relative to controls on tasks assessing verbal and non-verbal long-term memory, frontal functions, and visuospatial functions. Patients with OLE had poorer performance than patients with TLE on visuospatial tasks, whereas patients with TLE performed worse than patients with OLE on verbal long-term memory test. Discriminant analysis identified two canonical discriminant functions: The first explained 53.3% of the variance, and the second explained 46.7% of the variance. The first function included verbal and non-verbal memory tests distinguishing controls from both OLE and TLE, whereas the second factor including a visuoconstructional test distinguished OLE from TLE and controls. The results demonstrate that visuoconstructional dysfunction is related to OLE and support the idea that alterations of occipito-parietal stream may be specific to patients with OLE. © 2015 The British Psychological Society.

Visual interhemispheric communication and callosal connections of the occipital lobes.

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Berlucchi, Giovanni

2014-07-01

Callosal connections of the occipital lobes, coursing in the splenium of the corpus callosum, have long been thought to be crucial for interactions between the cerebral hemispheres in vision in both experimental animals and humans. Yet the callosal connections of the temporal and parietal lobes appear to have more important roles than those of the occipital callosal connections in at least some high-order interhemispheric visual functions. The partial intermixing and overlap of temporal, parietal and occipital callosal connections within the splenium has made it difficult to attribute the effects of splenial pathological lesions or experimental sections to splenial components specifically related to select cortical areas. The present review describes some current contributions from the modern techniques for the tracking of commissural fibers within the living human brain to the tentative assignation of specific visual functions to specific callosal tracts, either occipital or extraoccipital. Copyright © 2013 Elsevier Ltd. All rights reserved.

Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

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Andrew D. Robertson

2017-09-01

Full Text Available Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL magnetic resonance imaging (MRI in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF and the spatial coefficient of variation of CBF (sCoV were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73 and excellent reliability for sCoV (ICC = 0.94. In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036. The greatest change occurred in the parietal lobe (+18 ± 12%. Gray matter sCoV, however, did not change following training (P = 0.31. This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries.

Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

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Robertson, Andrew D.; Marzolini, Susan; Middleton, Laura E.; Basile, Vincenzo S.; Oh, Paul I.; MacIntosh, Bradley J.

2017-01-01

Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL) magnetic resonance imaging (MRI) in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF) and the spatial coefficient of variation of CBF (sCoV) were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC) indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73) and excellent reliability for sCoV (ICC = 0.94). In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036). The greatest change occurred in the parietal lobe (+18 ± 12%). Gray matter sCoV, however, did not change following training (P = 0.31). This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries. PMID:29033829

Emotion unfolded by motion: a role for parietal lobe in decoding dynamic facial expressions.

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Sarkheil, Pegah; Goebel, Rainer; Schneider, Frank; Mathiak, Klaus

2013-12-01

Facial expressions convey important emotional and social information and are frequently applied in investigations of human affective processing. Dynamic faces may provide higher ecological validity to examine perceptual and cognitive processing of facial expressions. Higher order processing of emotional faces was addressed by varying the task and virtual face models systematically. Blood oxygenation level-dependent activation was assessed using functional magnetic resonance imaging in 20 healthy volunteers while viewing and evaluating either emotion or gender intensity of dynamic face stimuli. A general linear model analysis revealed that high valence activated a network of motion-responsive areas, indicating that visual motion areas support perceptual coding for the motion-based intensity of facial expressions. The comparison of emotion with gender discrimination task revealed increased activation of inferior parietal lobule, which highlights the involvement of parietal areas in processing of high level features of faces. Dynamic emotional stimuli may help to emphasize functions of the hypothesized 'extended' over the 'core' system for face processing.

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…

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.

The relationship between neuropsychological tests of visuospatial function and lobar cortical thickness.

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Zink, Davor N; Miller, Justin B; Caldwell, Jessica Z K; Bird, Christopher; Banks, Sarah J

2018-06-01

Tests of visuospatial function are often administered in comprehensive neuropsychological evaluations. These tests are generally considered assays of parietal lobe function; however, the neural correlates of these tests, using modern imaging techniques, are not well understood. In the current study we investigated the relationship between three commonly used tests of visuospatial function and lobar cortical thickness in each hemisphere. Data from 374 patients who underwent a neuropsychological evaluation and MRI scans in an outpatient dementia clinic were included in the analysis. We examined the relationships between cortical thickness, as assessed with Freesurfer, and performance on three tests: Judgment of Line Orientation (JoLO), Block Design (BD) from the Fourth edition of the Wechsler Adult Intelligence Scale, and Brief Visuospatial Memory Test-Revised Copy Trial (BVMT-R-C) in patients who showed overall average performance on these tasks. Using a series of multiple regression models, we assessed which lobe's overall cortical thickness best predicted test performance. Among the individual lobes, JoLO performance was best predicted by cortical thickness in the right temporal lobe. BD performance was best predicted by cortical thickness in the right parietal lobe, and BVMT-R-C performance was best predicted by cortical thickness in the left parietal lobe. Performance on constructional tests of visuospatial function appears to correspond best with underlying cortical thickness of the parietal lobes, while performance on visuospatial judgment tests appears to correspond best to temporal lobe thickness. Future research using voxel-wise and connectivity techniques and including more diverse samples will help further understanding of the regions and networks involved in visuospatial tests.

Patterns of morphological integration between parietal and temporal areas in the human skull.

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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.

Decreased functional connectivity and structural deficit in alertness network with right-sided temporal lobe epilepsy.

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Gao, Yujun; Zheng, Jinou; Li, Yaping; Guo, Danni; Wang, Mingli; Cui, Xiangxiang; Ye, Wei

2018-04-01

Patients with temporal lobe epilepsy (TLE) often suffer from alertness alterations. However, specific regions connected with alertness remain controversial, and whether these regions have structural impairment is also elusive. This study aimed to investigate the characteristics and neural mechanisms underlying the functions and structures of alertness network in patients with right-sided temporal lobe epilepsy (rTLE) by performing the attentional network test (ANT), resting-state functional magnetic resonance imaging (R-SfMRI), and diffusion tensor imaging (DTI).A total of 47 patients with rTLE and 34 healthy controls underwent ANT, R-SfMRI, and DTI scan. The seed-based functional connectivity (FC) method and deterministic tractography were used to analyze the data.Patients with rTLE had longer reaction times in the no-cue and double-cue conditions. However, no differences were noted in the alertness effect between the 2 groups. The patient group had lower FC compared with the control group in the right inferior parietal lobe (IPL), amygdala, and insula. Structural deficits were found in the right parahippocampal gyrus, superior temporal pole, insula, and amygdala in the patient group compared with the control group. Also significantly negative correlations were observed between abnormal fractional anisotropy (between the right insula and the superior temporal pole) and illness duration in the patients with rTLE.The findings of this study suggested abnormal intrinsic and phasic alertness, decreased FC, and structural deficits within the alerting network in the rTLE. This study provided new insights into the mechanisms of alertness alterations in rTLE.

The extratemporal lobe epilepsies in the epilepsy monitoring unit

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Dash, Deepa; Tripathi, Manjari

2014-01-01

Extratemporal lobe epilepsies (ETLE) are characterized by the epileptogenic foci outside the temporal lobe. They have a wide spectrum of semiological presentation depending upon the site of origin. They can arise from frontal, parietal, occipital lobes and from hypothalamic hamartoma. We discuss in this review the semiology of different types of ETLE encountered in the epilepsy monitoring unit. PMID:24791090

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

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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.

Medical image of the week: azygous lobe

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Bhupinder Natt

2013-12-01

Full Text Available No abstract available. Article truncated at 150 words. A 59 year old man underwent chest radiography for evaluation of fever and cough. Imaging showed an accessory azygous lobe. An azygos lobe is found in 1% of anatomic specimens and forms when the right posterior cardinal vein, one of the precursors of the azygos vein, fails to migrate over the apex of the lung (1. Instead, the vein penetrates the lung carrying along pleural layers that entrap a portion of the right upper lobe. The vein appears to run within the lung, but is actually surrounded by both parietal and visceral pleura. The azygos fissure therefore consists of four layers of pleura, two parietal layers and two visceral layers, which wrap around the vein giving the appearance of a tadpole. Apart from an interesting incidental radiological finding, it is of limited clinical importance except that its presence should be recognized during thoracoscopic procedures. This patient was found to have …

Acupuncture at Waiguan (SJ5) and sham points influences activation of functional brain areas of ischemic stroke patients: a functional magnetic resonance imaging study.

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Qi, Ji; Chen, Junqi; Huang, Yong; Lai, Xinsheng; Tang, Chunzhi; Yang, Junjun; Chen, Hua; Qu, Shanshan

2014-02-01

Most studies addressing the specificity of meridians and acupuncture points have focused mainly on the different neural effects of acupuncture at different points in healthy individuals. This study examined the effects of acupuncture on brain function in a pathological context. Sixteen patients with ischemic stroke were randomly assigned to true point group (true acupuncture at right Waiguan (SJ5)) and sham point group (sham acupuncture). Results of functional magnetic resonance imaging revealed activation in right parietal lobe (Brodmann areas 7 and 19), the right temporal lobe (Brodmann area 39), the right limbic lobe (Brodmann area 23) and bilateral occipital lobes (Brodmann area 18). Furthermore, inhibition of bilateral frontal lobes (Brodmann area 4, 6, and 45), right parietal lobe (Brodmann areas 1 and 5) and left temporal lobe (Brodmann area 21) were observed in the true point group. Activation in the precuneus of right parietal lobe (Brodmann area 7) and inhibition of the left superior frontal gyrus (Brodmann area 10) was observed in the sham group. Compared with sham acupuncture, acupuncture at Waiguan in stroke patients inhibited Brodmann area 5 on the healthy side. Results indicated that the altered specificity of sensation-associated cortex (Brodmann area 5) is possibly associated with a central mechanism of acupuncture at Waiguan for stroke patients.

Magnetic resonance imaging of functional connectivity in Parkinson disease in the resting brain

International Nuclear Information System (INIS)

Liu Xian; Liu Bo; Luo Xiaodong; Li Ningna; Chen Zhiguang; Chen Jun

2009-01-01

Objective: To investigate functional connectivity changes in Parkinson disease in the resting brain using functional magnetic resonance imaging. Methods: Nine patients with Parkinson disease and eight age-matched healthy volunteers were entered into the study. The bilateral globus pallidus were chosen as seed points, the functional MR data acquired in the resting state were processed to investigate functional connectivity in PD patients and the results were compared with those of the controls. Results: In age-matched healthy controls, there are regions which had functional connectivity with bilateral globus pallidus, including bilateral temporal poles, bilateral hippocampus, bilateral thalami, posterior cingulate cortex, right middle occipital gyms and right superior parietal gyms. In PD patients, brain regions including bilateral cerebellum, left hippocampus, bilateral superior temporal gyri, left inferior frontal gyrus, left middle frontal gyrus, left precentral gyrus, left inferior parietal gyrus and left superior parietal gyrus, had functional connectivity with bilateral globus pallidus. Compared to healthy controls, increased functional connectivity in bilateral cerebellum, bilateral temporal lobes, left frontal lobe and left parietal lobe, and decreased functional connectivity in bilateral thalami were observed in PD patients. Conclusion: Abnormal changes of brain functional connectivity exists in Parkinson's disease in the resting state. (authors)

Inverted Lobes Have Satisfactory Functions Compared With Noninverted Lobes in Lung Transplantation.

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Kayawake, Hidenao; Chen-Yoshikawa, Toyofumi F; Motoyama, Hideki; Hamaji, Masatsugu; Hijiya, Kyoko; Aoyama, Akihiro; Goda, Yasufumi; Oda, Hiromi; Ueda, Satoshi; Date, Hiroshi

2018-04-01

To overcome the problem of small-for-size grafts in standard living-donor lobar lung transplantation (LDLLT), we developed inverted LDLLT, in which a right lower lobe from 1 donor is implanted as a right graft and another right lower lobe from another donor is implanted as a left graft. We retrospectively analyzed the functions of inverted grafts vs noninverted grafts. Between 2008 and 2015, 64 LDLLTs were performed. Included were 35 LDLLTs whose recipients were adults and monitored for more than 6 months without developing chronic lung allograft dysfunction. Among them, 65 implanted lobes were eligible for this analysis. There were 31 right lower lobes implanted as right grafts (right-to-right group), 7 right lower lobes as inverted left grafts (right-to-left group), and 27 left lower lobes as left grafts (left-to-left group). We evaluated the graft forced vital capacity (G-FVC) and graft volume of the 65 lobes before and 6 months after LDLLT and compared them among the three groups. Preoperatively, G-FVC in the right-to-left group (1,050 mL) was comparable to that in the right-to-right group (1,177 mL) and better than that in the left-to-left group (791 mL, p satisfactory compared with those of noninverted grafts. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Comparative proteomic analyses of the parietal lobe from rhesus monkeys fed a high-fat/sugar diet with and without resveratrol supplementation, relative to a healthy diet: Insights into the roles of unhealthy diets and resveratrol on function.

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Swomley, Aaron M; Triplett, Judy C; Keeney, Jeriel T; Warrier, Govind; Pearson, Kevin J; Mattison, Julie A; de Cabo, Rafael; Cai, Jian; Klein, Jon B; Butterfield, D Allan

2017-01-01

A diet consisting of a high intake of saturated fat and refined sugars is characteristic of a Western-diet and has been shown to have a substantial negative effect on human health. Expression proteomics were used to investigate changes to the parietal lobe proteome of rhesus monkeys consuming either a high fat and sugar (HFS) diet, a HFS diet supplemented with resveratrol (HFS+RSV), or a healthy control diet for 2 years. Here we discuss the modifications in the levels of 12 specific proteins involved in various cellular systems including metabolism, neurotransmission, structural integrity, and general cellular signaling following a nutritional intervention. Our results contribute to a better understanding of the mechanisms by which resveratrol functions through the up- or down-regulation of proteins in different cellular sub-systems to affect the overall health of the brain. Copyright © 2016 Elsevier Inc. All rights reserved.

Frontal lobe atrophy in motor neuron diseases.

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Kiernan, J A; Hudson, A J

1994-08-01

Neuronal degeneration in the precentral gyrus alone cannot account for the occurrence of spastic paresis in motor neuron diseases. To look for more extensive cortical atrophy we measured MRIs of the upper parts of the frontal and parietal lobes in 11 sporadic cases of classical amyotrophic lateral sclerosis (ALS), eight patients with primary lateral sclerosis (PLS) and an age- and sex-matched group of 49 neurologically normal people. None of the patients had overt dementia or other mental diseases. In PLS there is progressive spastic paresis but in contrast to ALS there is no lower motor neuron degeneration. The surface area of the precentral gyri and the amount of underlying white matter in PLS were consistently approximately 75% of the normal size. By contrast, there was some shrinkage of the precentral gyri in some of the ALS patients but the mean measurements for the group did not differ significantly from the controls. Anterior to the precentral sulci, the cortical surface area in PLS was approximately 85% of that of the controls, with correspondingly reduced white matter. In ALS the cortical surface areas of the anterior frontal lobes did not differ from those of the controls, but the amount of underlying white matter was reduced almost as much in ALS as it was in PLS. The measured changes in the frontal lobes suggest that in PLS there is simultaneous atrophy of the primary, premotor and supplementary motor areas of the cortex, with consequent degeneration of corticospinal and corticoreticular axons descending through the underlying white matter. These changes could account for the progressive upper motor neuron syndrome. In ALS, with no significant frontal cortical atrophy, the shrinkage of the white matter may be due to degeneration of axons projecting to the frontal cortex from elsewhere. Deprivation of afferents could explain the diminution of motor functions of the frontal lobes in ALS and also the changes in word fluency, judgement and attention that

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)

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

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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.

IMAGING OF BRAIN FUNCTION BASED ON THE ANALYSIS OF FUNCTIONAL CONNECTIVITY - IMAGING ANALYSIS OF BRAIN FUNCTION BY FMRI AFTER ACUPUNCTURE AT LR3 IN HEALTHY INDIVIDUALS.

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Zheng, Yu; Wang, Yuying; Lan, Yujun; Qu, Xiaodong; Lin, Kelin; Zhang, Jiping; Qu, Shanshan; Wang, Yanjie; Tang, Chunzhi; Huang, Yong

2016-01-01

This Study observed the relevant brain areas activated by acupuncture at the Taichong acupoint (LR3) and analyzed the functional connectivity among brain areas using resting state functional magnetic resonance imaging (fMRI) to explore the acupoint specificity of the Taichong acupoint. A total of 45 healthy subjects were randomly divided into the Taichong (LR3) group, sham acupuncture group and sham acupoint group. Subjects received resting state fMRI before acupuncture, after true (sham) acupuncture in each group. Analysis of changes in connectivity among the brain areas was performed using the brain functional connectivity method. The right cerebrum temporal lobe was selected as the seed point to analyze the functional connectivity. It had a functional connectivity with right cerebrum superior frontal gyrus, limbic lobe cingulate gyrus and left cerebrum inferior temporal gyrus (BA 37), inferior parietal lobule compared by before vs. after acupuncture at LR3, and right cerebrum sub-lobar insula and left cerebrum middle frontal gyrus, medial frontal gyrus compared by true vs. sham acupuncture at LR3, and right cerebrum occipital lobe cuneus, occipital lobe sub-gyral, parietal lobe precuneus and left cerebellum anterior lobe culmen by acupuncture at LR3 vs. sham acupoint. Acupuncture at LR3 mainly specifically activated the brain functional network that participates in visual function, associative function, and emotion cognition, which are similar to the features on LR3 in tradition Chinese medicine. These brain areas constituted a neural network structure with specific functions that had specific reference values for the interpretation of the acupoint specificity of the Taichong acupoint.

[Mirror movement due to the medial frontal lobe lesion].

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Takahashi, N; Kawamura, M; Hirayama, K

1995-01-01

We reported a case with acquired mirror movement in upper limbs due to the lesion of right medial frontal lobe including supplementary motor area, and also discussed a possible mechanism underlying it. A 59-year-old right-handed woman developed left hemiparesis caused by cerebral hemorrhage in the right frontoparietal lobe, on April 5, 1981. She had right hemiparesis and right hemianopsia due to cerebral hemorrhage in the left parieto-occipital lobe, 13 days later. As the patient was recovering from paresis, mirror movement appeared on upper limbs. The features of the mirror movement of this case are summarized as follows: (1) it appeared when using both proximal and distal region of upper limbs; (2) it appeared on left upper limb when the patient intended to move right upper limb or on right upper limb when intended to move left upper limb, while it appeared predominantly in the former; and (3) it was more remarkably found in habitual movement using gesture and pantomimic movement for the use of objects, and it was found in lower degree when actual object was used or when the patient tried to imitate the gesture of the examiner. The lesions in MRI were found in medial region of right frontal lobe (supplementary motor area, medial region of motor area, and cingulate gyrus), right medial parietal lobe, posterior region of right occipital lobe, and medial regions of left parietal and occipital lobes. There was no apparent abnormality in corpus callosum.(ABSTRACT TRUNCATED AT 250 WORDS)

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

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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

Cognitive deficits are associated with frontal and temporal lobe white matter lesions in middle-aged adults living in the community.

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David Bunce

Full Text Available BACKGROUND: The association between brain white matter lesions and cognitive impairment in old age is well established. However, little is known about this association in midlife. As this information will inform policy for early preventative healthcare initiatives, we investigated non-periventricular frontal, temporal, parietal and occipital lobe white matter hyperintensities (WMH in relation to cognitive function in 428 (232 women community-dwelling adults aged 44 to 48 years. RESULTS: Frontal white matter lesions were significantly associated with greater intraindividual RT variability in women, while temporal WMH were associated with face recognition deficits in men. Parietal and occipital lobe lesions were unrelated to cognitive performance. These findings did not differ when education and a range of health variables, including vascular risk factors, were taken into account. CONCLUSION: Gender differences in WMH-cognition associations are discussed, and we conclude that small vessel disease is present in midlife and has functional consequences which are generally not recognized. Preventative strategies should, therefore, begin early in life.

Functional interaction between right parietal and bilateral frontal cortices during visual search tasks revealed using functional magnetic imaging and transcranial direct current stimulation.

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Amanda Ellison

Full Text Available The existence of a network of brain regions which are activated when one undertakes a difficult visual search task is well established. Two primary nodes on this network are right posterior parietal cortex (rPPC and right frontal eye fields. Both have been shown to be involved in the orientation of attention, but the contingency that the activity of one of these areas has on the other is less clear. We sought to investigate this question by using transcranial direct current stimulation (tDCS to selectively decrease activity in rPPC and then asking participants to perform a visual search task whilst undergoing functional magnetic resonance imaging. Comparison with a condition in which sham tDCS was applied revealed that cathodal tDCS over rPPC causes a selective bilateral decrease in frontal activity when performing a visual search task. This result demonstrates for the first time that premotor regions within the frontal lobe and rPPC are not only necessary to carry out a visual search task, but that they work together to bring about normal function.

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.

Relation between fluid intelligence and frontal lobe functioning in older adults.

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Isingrini, M; Vazou, F

1997-01-01

This study reports the relations among normal aging, intelligence, and frontal lobe functioning. Intelligence tasks and frontal lobe functioning tasks were administered to 107 adults from two age groups (25 to 46 years and 70 to 99 years). Intelligence measures were assessed with two crystallized tests (WAIS Vocabulary and Information subtests), one fluid intelligence test (Cattell's Matrices), and one mixed, crystallized and fluid test (WAIS Similarities subtest). Frontal functioning was assessed using the Wisconsin Card Sorting Test (WCST) and two tests of verbal fluency. Significant age differences in favor of the young were found on the two intelligence tests with a fluid component and on all measures of frontal lobe functioning. Correlational analyses examining the relationship of intelligence measures to frontal variables indicated that these last measures were significantly correlated with only fluid intelligence tests in the elderly group. The implications for the relations among aging, fluid intelligence, and frontal lobe functioning are discussed.

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

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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.

Functional connectivity evidence of cortico-cortico inhibition in temporal lobe epilepsy.

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Tracy, Joseph I; Osipowicz, Karol; Spechler, Philip; Sharan, Ashwini; Skidmore, Christopher; Doucet, Gaelle; Sperling, Michael R

2014-01-01

Epileptic seizures can initiate a neural circuit and lead to aberrant neural communication with brain areas outside the epileptogenic region. We focus on interictal activity in focal temporal lobe epilepsy and evaluate functional connectivity (FC) differences that emerge as function of bilateral versus strictly unilateral epileptiform activity. We assess the strength of FC at rest between the ictal and non-ictal temporal lobes, in addition to whole brain connectivity with the ictal temporal lobe. Results revealed strong connectivity between the temporal lobes for both patient groups, but this did not vary as a function of unilateral versus bilateral interictal status. Both the left and right unilateral temporal lobe groups showed significant anti-correlated activity in regions outside the epileptogenic temporal lobe, primarily involving the contralateral (non-ictal/non-pathologic) hemisphere, with precuneus involvement prominent. The bilateral groups did not show this contralateral anti-correlated activity. This anti-correlated connectivity may represent a form of protective and adaptive inhibition, helping to constrain epileptiform activity to the pathologic temporal lobe. The absence of this activity in the bilateral groups may be indicative of flawed inhibitory mechanisms, helping to explain their more widespread epileptiform activity. Our data suggest that the location and build up of epilepsy networks in the brain are not truly random, and are not limited to the formation of strictly epileptogenic networks. Functional networks may develop to take advantage of the regulatory function of structures such as the precuneus to instantiate an anti-correlated network, generating protective cortico-cortico inhibition for the purpose of limiting seizure spread or epileptogenesis. Copyright © 2012 Wiley Periodicals, Inc.

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

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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.

Thalamo-Cortical Disruption Contributes to Short-Term Memory Deficits in Patients with Medial Temporal Lobe Damage.

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Voets, Natalie L; Menke, Ricarda A L; Jbabdi, Saad; Husain, Masud; Stacey, Richard; Carpenter, Katherine; Adcock, Jane E

2015-11-01

Short-term (STM) and long-term memory (LTM) have largely been considered as separate brain systems reflecting fronto-parietal and medial temporal lobe (MTL) functions, respectively. This functional dichotomy has been called into question by evidence of deficits on aspects of working memory in patients with MTL damage, suggesting a potentially direct hippocampal contribution to STM. As the hippocampus has direct anatomical connections with the thalamus, we tested the hypothesis that damage to thalamic nuclei regulating cortico-cortical interactions may contribute to STM deficits in patients with hippocampal dysfunction. We used diffusion-weighted magnetic resonance imaging-based tractography to identify anatomical subdivisions in patients with MTL epilepsy. From these, we measured resting-state functional connectivity with detailed cortical divisions of the frontal, temporal, and parietal lobes. Whereas thalamo-temporal functional connectivity reflected LTM performance, thalamo-prefrontal functional connectivity specifically predicted STM performance. Notably, patients with hippocampal volume loss showed thalamic volume loss, most prominent in the pulvinar region, not detected in patients with normal hippocampal volumes. Aberrant thalamo-cortical connectivity in the epileptic hemisphere was mirrored in a loss of behavioral association with STM performance specifically in patients with hippocampal atrophy. These findings identify thalamo-cortical disruption as a potential mechanism contributing to STM deficits in the context of MTL damage. © The Author 2015. Published by Oxford University Press.

Parallel Alterations of Functional Connectivity during Execution and Imagination after Motor Imagery Learning

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Zhang, Rushao; Hui, Mingqi; Long, Zhiying; Zhao, Xiaojie; Yao, Li

2012-01-01

Background Neural substrates underlying motor learning have been widely investigated with neuroimaging technologies. Investigations have illustrated the critical regions of motor learning and further revealed parallel alterations of functional activation during imagination and execution after learning. However, little is known about the functional connectivity associated with motor learning, especially motor imagery learning, although benefits from functional connectivity analysis attract more attention to the related explorations. We explored whether motor imagery (MI) and motor execution (ME) shared parallel alterations of functional connectivity after MI learning. Methodology/Principal Findings Graph theory analysis, which is widely used in functional connectivity exploration, was performed on the functional magnetic resonance imaging (fMRI) data of MI and ME tasks before and after 14 days of consecutive MI learning. The control group had no learning. Two measures, connectivity degree and interregional connectivity, were calculated and further assessed at a statistical level. Two interesting results were obtained: (1) The connectivity degree of the right posterior parietal lobe decreased in both MI and ME tasks after MI learning in the experimental group; (2) The parallel alterations of interregional connectivity related to the right posterior parietal lobe occurred in the supplementary motor area for both tasks. Conclusions/Significance These computational results may provide the following insights: (1) The establishment of motor schema through MI learning may induce the significant decrease of connectivity degree in the posterior parietal lobe; (2) The decreased interregional connectivity between the supplementary motor area and the right posterior parietal lobe in post-test implicates the dissociation between motor learning and task performing. These findings and explanations further revealed the neural substrates underpinning MI learning and supported that

Default network connectivity in medial temporal lobe amnesia.

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Hayes, Scott M; Salat, David H; Verfaellie, Mieke

2012-10-17

There is substantial overlap between the brain regions supporting episodic memory and the default network. However, in humans, the impact of bilateral medial temporal lobe (MTL) damage on a large-scale neural network such as the default mode network is unknown. To examine this issue, resting fMRI was performed with amnesic patients and control participants. Seed-based functional connectivity analyses revealed robust default network connectivity in amnesia in cortical default network regions such as medial prefrontal cortex, posterior medial cortex, and lateral parietal cortex, as well as evidence of connectivity to residual MTL tissue. Relative to control participants, decreased posterior cingulate cortex connectivity to MTL and increased connectivity to cortical default network regions including lateral parietal and medial prefrontal cortex were observed in amnesic patients. In contrast, somatomotor network connectivity was intact in amnesic patients, indicating that bilateral MTL lesions may selectively impact the default network. Changes in default network connectivity in amnesia were largely restricted to the MTL subsystem, providing preliminary support from MTL amnesic patients that the default network can be fractionated into functionally and structurally distinct components. To our knowledge, this is the first examination of the default network in amnesia.

Differential frontal-parietal phase synchrony during hypnosis as a function of hypnotic suggestibility.

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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.

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

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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.

Multimodal imaging of language reorganization in patients with left temporal lobe epilepsy.

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Chang, Yu-Hsuan A; Kemmotsu, Nobuko; Leyden, Kelly M; Kucukboyaci, N Erkut; Iragui, Vicente J; Tecoma, Evelyn S; Kansal, Leena; Norman, Marc A; Compton, Rachelle; Ehrlich, Tobin J; Uttarwar, Vedang S; Reyes, Anny; Paul, Brianna M; McDonald, Carrie R

2017-07-01

This study explored the relationships among multimodal imaging, clinical features, and language impairment in patients with left temporal lobe epilepsy (LTLE). Fourteen patients with LTLE and 26 controls underwent structural MRI, functional MRI, diffusion tensor imaging, and neuropsychological language tasks. Laterality indices were calculated for each imaging modality and a principal component (PC) was derived from language measures. Correlations were performed among imaging measures, as well as to the language PC. In controls, better language performance was associated with stronger left-lateralized temporo-parietal and temporo-occipital activations. In LTLE, better language performance was associated with stronger right-lateralized inferior frontal, temporo-parietal, and temporo-occipital activations. These right-lateralized activations in LTLE were associated with right-lateralized arcuate fasciculus fractional anisotropy. These data suggest that interhemispheric language reorganization in LTLE is associated with alterations to perisylvian white matter. These concurrent structural and functional shifts from left to right may help to mitigate language impairment in LTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

Cognitive Functioning in Temporal Lobe Epilepsy: A BOLD-fMRI Study.

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Guo, Lili; Bai, Genji; Zhang, Hui; Lu, Daoyan; Zheng, Jiyong; Xu, Gang

2017-12-01

We aimed to analyze the association between resting-state functional magnetic resonance imaging (re-fMRI) and cognitive function (including language, executive, and memory functions) in temporal lobe epilepsy (TLE) patients, which will help to explore the mechanism of brain function in patients. 15 TLE patients and 15 non-TLE patients were recruited. All subjects underwent neuropsychological testing and memory functional evaluation. Changes in verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), full intelligence quotient (FIQ), and memory quotient (MQ) were compared between two groups. Re-fMRI data were also collected from two groups to evaluate these changes. Each individual score of neuropsychological testing and memory functional evaluation were higher in control group, which was statistically different (all P temporal gyrus back, right superior temporal gyrus, left cerebellum, left angular gyrus, left wedge anterior lobe, and left central back; while the negatively activated brain regions were left prefrontal, right cerebellum, right corner back, and right anterior cingulate gyrus. During the language task, the activated brain regions of the TLE patients were right prefrontal lobe, the lateral temporal gyri, the left cerebellum, left cornu laterale gyrus, left precuneus, and the left postcentral gyrus, whereas the negatively activated brain areas were the left prefrontal cortex, the right cerebellum, right cornu laterale gyrus, and the right anterior cingulate gyrus. During the executive task, epilepsy patients showed activation difference in right prefrontal and right frontal lobe and right brain, left superior temporal gyrus, and right cerebellum anterior lobe compared with the control group; no negatively activated differences in brain areas. During the memory task, the difference lay in bilateral anterior cingulate gyrus and bilateral wedge anterior lobe while the negatively activated brain areas were the left inferior frontal

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.

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

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

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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

Human middle longitudinal fascicle: segregation and behavioral-clinical implications of two distinct fiber connections linking temporal pole and superior temporal gyrus with the angular gyrus or superior parietal lobule using multi-tensor tractography.

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Makris, N; Preti, M G; Wassermann, D; Rathi, Y; Papadimitriou, G M; Yergatian, C; Dickerson, B C; Shenton, M E; Kubicki, M

2013-09-01

The middle longitudinal fascicle (MdLF) is a major fiber connection running principally between the superior temporal gyrus and the parietal lobe, neocortical regions of great biological and clinical interest. Although one of the most prominent cerebral association fiber tracts, it has only recently been discovered in humans. In this high angular resolution diffusion imaging (HARDI) MRI study, we delineated the two major fiber connections of the human MdLF, by examining morphology, topography, cortical connections, biophysical measures, volume and length in seventy-four brains. These two fiber connections course together through the dorsal temporal pole and the superior temporal gyrus maintaining a characteristic topographic relationship in the mediolateral and ventrodorsal dimensions. As these pathways course towards the parietal lobe, they split to form separate fiber pathways, one following a ventrolateral trajectory and connecting with the angular gyrus and the other following a dorsomedial route and connecting with the superior parietal lobule. Based on the functions of their cortical affiliations, we suggest that the superior temporal-angular connection of the MdLF, i.e., STG(MdLF)AG plays a role in language and attention, whereas the superior temporal-superior parietal connection of the MdLF, i.e., STG(MdLF)SPL is involved in visuospatial and integrative audiovisual functions. Furthermore, the MdLF may have clinical implications in neurodegenerative disorders such as primary progressive aphasia, frontotemporal dementia, posterior cortical atrophy, corticobulbar degeneration and Alzheimer's disease as well as attention-deficit/hyperactivity disorder and schizophrenia.

Quantifying interictal metabolic activity in human temporal lobe epilepsy

International Nuclear Information System (INIS)

Henry, T.R.; Mazziotta, J.C.; Engel, J. Jr.; Christenson, P.D.; Zhang, J.X.; Phelps, M.E.; Kuhl, D.E.

1990-01-01

The majority of patients with complex partial seizures of unilateral temporal lobe origin have interictal temporal hypometabolism on [18F]fluorodeoxyglucose positron emission tomography (FDG PET) studies. Often, this hypometabolism extends to ipsilateral extratemporal sites. The use of accurately quantified metabolic data has been limited by the absence of an equally reliable method of anatomical analysis of PET images. We developed a standardized method for visual placement of anatomically configured regions of interest on FDG PET studies, which is particularly adapted to the widespread, asymmetric, and often severe interictal metabolic alterations of temporal lobe epilepsy. This method was applied by a single investigator, who was blind to the identity of subjects, to 10 normal control and 25 interictal temporal lobe epilepsy studies. All subjects had normal brain anatomical volumes on structural neuroimaging studies. The results demonstrate ipsilateral thalamic and temporal lobe involvement in the interictal hypometabolism of unilateral temporal lobe epilepsy. Ipsilateral frontal, parietal, and basal ganglial metabolism is also reduced, although not as markedly as is temporal and thalamic metabolism

Insight in psychotic disorder: relation with psychopathology and frontal lobe function.

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Kumar, Atmesh; Sharma, Pranjal; Das, Shyamanta; Nath, Kamal; Talukdar, Uddip; Bhagabati, Dipesh

2014-01-01

Through conceptualising poor insight in psychotic disorders as a form of anosognosia, frontal lobe dysfunction is often ascribed a vital role in its pathogenesis. The objective of this study was to compare the relation of insight in patients with psychotic illness to that of psychopathology and frontal lobe function. Forty patients with psychotic disorder were selected from those attending the Department of Psychiatry in a tertiary care teaching hospital. The evaluation of insight was carried out using the Schedule for Assessment of Insight (SAI), that of frontal lobe function by the Frontal Assessment Battery (FAB) and psychopathology by the Brief Psychiatric Rating Scale (BPRS). The correlation coefficients were determined. A negative correlation between SAI and BPRS scores means that the BPRS score is opposite to SAI scores. When the SAI total score was compared with the FAB total score, the correlation coefficient demonstrated a positive correlation. Better insight predicted lesser psychopathology and also that poor insight would exist with greater psychopathology. Better insight predicted a higher functional status of frontal lobes and prefrontal cortex in particular. Insight deficits in schizophrenia and other psychotic illnesses are multidimensional. Integration of different aetiological factors like biological, psychopathological, environmental ones and others are necessary for a better understanding of insight in psychosis. Copyright © 2013 S. Karger AG, Basel.

Body-centred map in parietal eye fields - functional MRI study

International Nuclear Information System (INIS)

Brotchie, P.; Chen, D.Y.; Bradley, W.G.

2002-01-01

Full text: In order for us to interact with our environment we need to know where objects are around us, relative to our body. In monkeys, a body-centred map of visual space is known to exist within the parietal eye fields. This map is formed by the modulation of neuronal activity by eye and head position (Brotchie et al, Nature 1995; Synder et al, Nature 1998). In humans no map of body centred space has been demonstrated. By using functional MRI we have localised a region along the intraparietal sulcus which has properties similar to the parietal eye fields of monkeys (Brotchie et al, ISMRM, 2000). The aim of this study was to determine if activity in this region is modulated by head position, consistent with a body centered representation of visual space. Functional MRI was performed on 6 subjects performing simple visually guided saccades using a 1.5 Tesla GE Echospeed scanner. 10 scans were performed on the 6 subjects at left and right body orientations. Regions of interest were selected around the intraparietal sulcus proper (IPSP) of both hemispheres and voxels with BOLD signal which correlated with the paradigm (r>0.35) were selected for further analysis. Comparisons of percentage signal change were made between the left and right IPSP using Student t test. Of the 10 MRI examinations, 6 demonstrated statistically significant differences in the amount of signal change between left and right IPSP. In each of these 6 cases, the signal change was greater within the IPSP contralateral to the direction of head position relative to the body. This indicates a modulation of activity within the IPSP related to head position, most likely reflecting modulation of the underlying neuronal activity and suggests the existence of a body-centred encoding of space within the parietal eye fields of humans. Copyright (2002) Blackwell Science Pty Ltd

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

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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.

Bilingualism Alters Children's Frontal Lobe Functioning for Attentional Control

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Arredondo, Maria M.; Hu, Xiao-Su; Satterfield, Teresa; Kovelman, Ioulia

2017-01-01

Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on children's cognitive and brain development. Theories of bilingualism suggest early dual-language acquisition can improve children's cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present much conflicting evidence, little is known about its effects on children's frontal lobe development. Using functional Near-Infrared Spectroscopy (fNIRS), the findings suggest that Spanish-English bilingual children (n=13, ages 7-13) had greater activation in left prefrontal cortex during a non-verbal attentional control task relative to age-matched English monolinguals. In contrast, monolinguals (n=14) showed greater right prefrontal activation than bilinguals. The present findings suggest early bilingualism yields significant changes to the functional organization of children's prefrontal cortex for attentional control and carry implications for understanding how early life experiences impact cognition and brain development. PMID:26743118

Neuromagnetic vistas into typical and atypical development of frontal lobe functions

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Margot J Taylor

2014-06-01

Full Text Available The frontal lobes are involved in many higher-order cognitive functions such as social cognition executive functions and language and speech. These functions are complex and follow a prolonged developmental course from childhood through to early adulthood. Magnetoencephalography (MEG is ideal for the study of development of these functions, due to its combination of temporal and spatial resolution which allows the determination of age-related changes in both neural timing and location. There are several challenges for MEG developmental studies: to design tasks appropriate to capture the neurodevelopmental trajectory of these cognitive functions, and to develop appropriate analysis strategies to capture various aspects of neuromagnetic frontal lobe activity. Here, we review our MEG research on social and executive functions, and speech in typically developing children and in two clinical groups – children with ASD and children born very preterm. The studies include facial emotional processing, inhibition, visual short-term memory, speech production and resting-state networks. We present data from event-related analyses as well as on oscillations and connectivity analyses and review their contributions to understanding frontal lobe cognitive development. We also discuss the challenges of testing young children in the MEG and the development of age-appropriate technologies and paradigms.

Frontal lobe function in chess players.

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Nejati, Majid; Nejati, Vahid

2012-01-01

Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST) data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players don't have any preference in any stage of Stroop test. Chess players don't have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

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

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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.

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

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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

[Neuroanatomy of the Parietal Association Areas].

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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.

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

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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…

Frontal Lobe Function in Chess Players

Directory of Open Access Journals (Sweden)

Vahid Nejati

2012-05-01

Full Text Available Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players dont have any preference in any stage of Stroop test. Chess players dont have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

Seizure Control and Memory Impairment Are Related to Disrupted Brain Functional Integration in Temporal Lobe Epilepsy.

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Park, Chang-Hyun; Choi, Yun Seo; Jung, A-Reum; Chung, Hwa-Kyoung; Kim, Hyeon Jin; Yoo, Jeong Hyun; Lee, Hyang Woon

2017-01-01

Brain functional integration can be disrupted in patients with temporal lobe epilepsy (TLE), but the clinical relevance of this disruption is not completely understood. The authors hypothesized that disrupted functional integration over brain regions remote from, as well as adjacent to, the seizure focus could be related to clinical severity in terms of seizure control and memory impairment. Using resting-state functional MRI data acquired from 48 TLE patients and 45 healthy controls, the authors mapped functional brain networks and assessed changes in a network parameter of brain functional integration, efficiency, to examine the distribution of disrupted functional integration within and between brain regions. The authors assessed whether the extent of altered efficiency was influenced by seizure control status and whether the degree of altered efficiency was associated with the severity of memory impairment. Alterations in the efficiency were observed primarily near the subcortical region ipsilateral to the seizure focus in TLE patients. The extent of regional involvement was greater in patients with poor seizure control: it reached the frontal, temporal, occipital, and insular cortices in TLE patients with poor seizure control, whereas it was limited to the limbic and parietal cortices in TLE patients with good seizure control. Furthermore, TLE patients with poor seizure control experienced more severe memory impairment, and this was associated with lower efficiency in the brain regions with altered efficiency. These findings indicate that the distribution of disrupted brain functional integration is clinically relevant, as it is associated with seizure control status and comorbid memory impairment.

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

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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…

The timing of associative memory formation: frontal lobe and anterior medial temporal lobe activity at associative binding predicts memory

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Hales, J. B.

2011-01-01

The process of associating items encountered over time and across variable time delays is fundamental for creating memories in daily life, such as for stories and episodes. Forming associative memory for temporally discontiguous items involves medial temporal lobe structures and additional neocortical processing regions, including prefrontal cortex, parietal lobe, and lateral occipital regions. However, most prior memory studies, using concurrently presented stimuli, have failed to examine the temporal aspect of successful associative memory formation to identify when activity in these brain regions is predictive of associative memory formation. In the current study, functional MRI data were acquired while subjects were shown pairs of sequentially presented visual images with a fixed interitem delay within pairs. This design allowed the entire time course of the trial to be analyzed, starting from onset of the first item, across the 5.5-s delay period, and through offset of the second item. Subjects then completed a postscan recognition test for the items and associations they encoded during the scan and their confidence for each. After controlling for item-memory strength, we isolated brain regions selectively involved in associative encoding. Consistent with prior findings, increased regional activity predicting subsequent associative memory success was found in anterior medial temporal lobe regions of left perirhinal and entorhinal cortices and in left prefrontal cortex and lateral occipital regions. The temporal separation within each pair, however, allowed extension of these findings by isolating the timing of regional involvement, showing that increased response in these regions occurs during binding but not during maintenance. PMID:21248058

Parietal cortex and representation of the mental Self

DEFF Research Database (Denmark)

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...

Bilingualism Alters Children's Frontal Lobe Functioning for Attentional Control

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Arredondo, Maria M.; Hu, Xiao-Su; Satterfield, Teresa; Kovelman, Ioulia

2017-01-01

Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on children's cognitive and brain development. Theories of bilingualism suggest that early dual-language acquisition can improve children's cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present…

MRI in patients with temporal lobe epilepsy

International Nuclear Information System (INIS)

Kodama, Kazuhiro

1992-01-01

The present study investigated magnetic resonance imaging (MRI) features in temporal lobe epilepsy and correlated them with clinical variables, such as age, illness duration, past history, and the frequency of seizure. Cerebral MRI was performed in 45 patients with temporal lobe epilepsy of unknown etiology, using a 0.5 T and/or a 1.5 T MRI systems. The temporal lobe was seen as high signal intensity on T2-weighted images and/or proton density-weighted images in 6 patients, although it was missed on CT and T1-weighted images. The high intensity area seemed to reflect sclerosis of the temporal lobe. This finding was significantly associated with partial seizure. Of these patients, 3 had a history of febrile convulsions. Ten patients had slight dilatation of the inferior horn of the lateral ventricle. They were significantly old at the time of onset and examination, as compared with those without dilatation. Furthermore, 6 patients with unilateral dilatation were significantly younger than the other 4 with bilateral dilatation. Nine patients had small multiple high signal areas in white matter, mainly in the parietal lobe, which suggested vascular origin. These patients were significantly old at the time of onset and examination, as compared with those having no such findings. In depicting high signal intensity areas, a 1.5 T MRI system was not always superior to a 0.5 T MRI system. Proton density-weighted images were better than T2-weighted images in some patients. (N.K.)

[Effects of temporal lobe epilepsy and idiopathic epilepsy on cognitive function and emotion in children].

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Yang, Xiao-Yan; Long, Li-Li; Xiao, Bo

2016-07-01

To investigate the effects of temporal lobe epilepsy and idiopathic epilepsy on cognitive function and emotion in children and the risk factors for cognitive impairment. A retrospective analysis was performed for the clinical data of 38 children with temporal lobe epilepsy and 40 children with idiopathic epilepsy. The controls were 42 healthy children. All subjects received the following neuropsychological tests: Montreal Cognitive Assessment (MoCA) scale, verbal fluency test, digit span test, block design test, Social Anxiety Scale for Children (SASC), and Depression Self-rating Scale for Children (DSRSC). Compared with the control group, the temporal lobe epilepsy and idiopathic epilepsy groups showed significantly lower scores of MoCA, verbal fluency, digit span, and block design (Pepilepsy group, the temporal lobe epilepsy group showed significantly lower scores of MoCA, verbal fluency, digit span, and block design (Ptemporal lobe epilepsy group, MoCA score was negatively correlated with SASC score, DSRSC score, and seizure frequency (r=-0.571, -0.529, and -0.545 respectively; Pepilepsy group, MoCA score was also negatively correlated with SASC score, DSRSC score, and seizure frequency (r=-0.542, -0.487, and -0.555 respectively; Ptemporal lobe epilepsy and idiopathic epilepsy show impaired whole cognition, verbal fluency, memory, and executive function and have anxiety and depression, which are more significant in children with temporal lobe epilepsy. High levels of anxiety, depression, and seizure frequency are risk factors for impaired cognitive function.

Graph theoretical analysis reveals disrupted topological properties of whole brain functional networks in temporal lobe epilepsy.

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Wang, Junjing; Qiu, Shijun; Xu, Yong; Liu, Zhenyin; Wen, Xue; Hu, Xiangshu; Zhang, Ruibin; Li, Meng; Wang, Wensheng; Huang, Ruiwang

2014-09-01

Temporal lobe epilepsy (TLE) is one of the most common forms of drug-resistant epilepsy. Previous studies have indicated that the TLE-related impairments existed in extensive local functional networks. However, little is known about the alterations in the topological properties of whole brain functional networks. In this study, we acquired resting-state BOLD-fMRI (rsfMRI) data from 26 TLE patients and 25 healthy controls, constructed their whole brain functional networks, compared the differences in topological parameters between the TLE patients and the controls, and analyzed the correlation between the altered topological properties and the epilepsy duration. The TLE patients showed significant increases in clustering coefficient and characteristic path length, but significant decrease in global efficiency compared to the controls. We also found altered nodal parameters in several regions in the TLE patients, such as the bilateral angular gyri, left middle temporal gyrus, right hippocampus, triangular part of left inferior frontal gyrus, left inferior parietal but supramarginal and angular gyri, and left parahippocampus gyrus. Further correlation analysis showed that the local efficiency of the TLE patients correlated positively with the epilepsy duration. Our results indicated the disrupted topological properties of whole brain functional networks in TLE patients. Our findings indicated the TLE-related impairments in the whole brain functional networks, which may help us to understand the clinical symptoms of TLE patients and offer a clue for the diagnosis and treatment of the TLE patients. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Neuropsychology and its correlation with cerebral blood flow in patients with Alzheimer's disease, vascular dementia and normal seniors

International Nuclear Information System (INIS)

Ang Qiuqing; Jiang Kaida; Huang Yanyan; Zhang Mingyuan; Zhao Jinghua; Lin Xiangtong; He Fengfeng; Gu Niufan

1999-01-01

Objective: To study the psychological, functional imaging findings and the relationship between them in patients with Alzheimer's disease (AD), vascular dementia (VD) and normal seniors (NS). Methods: Psychological evaluation with rating scales and functional imaging examination with single photon emission computed tomography were conducted to AD, VD (both met the DSM-IV diagnostic criteria) and NS. Results: In psychological examination, AD and VD showed significantly lower scores in every scale than NS, and in Fuld goods memory test (FOM), AD appeared even worse than VD. In functional imaging examination, at most brain areas, radioactive ratio (RAR) in AD and VD were obviously lower than that in NS. While in right parietal lobe and bilateral frontal lobes, RAR in AD showed significantly lower than in VD. FOM score of NS was correlated with RAR in several brain areas. RARs of right parietal lobe in AD and of left parietal lobe in VD showed correlation with scores of most rating scales. Conclusions: Hypoperfusion in right parietal lobe of AD and in left parietal lobe of VD contributes mainly to their cognitive deficiency, this may further suggest the different right or left hemisphere mechanism in AD and VD

Cognitive Function and Heat Shock Protein 70 in Children With Temporal Lobe Epilepsy.

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Oraby, Azza M; Raouf, Ehab R Abdol; El-Saied, Mostafa M; Abou-Khadra, Maha K; Helal, Suzette I; Hashish, Adel F

2017-01-01

We conducted the present study to examine cognitive function and serum heat shock protein 70 levels among children with temporal lobe epilepsy. The Stanford-Binet Intelligence Test was carried out to examine cognitive function in 30 children with temporal lobe epilepsy and 30 controls. Serum heat shock protein 70 levels were determined with an enzyme-linked immunosorbent assay. The epilepsy group had significantly lower cognitive function testing scores and significantly higher serum heat shock protein 70 levels than the control group; there were significant negative correlations between serum heat shock protein 70 levels and short-term memory and composite scores. Children with uncontrolled seizures had significantly lower verbal reasoning scores and significantly higher serum heat shock protein 70 levels than children with controlled seizures. Children with temporal lobe epilepsy have cognitive dysfunction and elevated levels of serum heat shock protein 70, which may be considered a stress biomarker.

Functional Clustering of the Human Inferior Parietal Lobule by Whole-Brain Connectivity Mapping of Resting-State Functional Magnetic Resonance Imaging Signals

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Li, Chiang-Shan R.

2014-01-01

Abstract The human inferior parietal lobule (IPL) comprised the lateral bank of the intraparietal sulcus, angular gyrus, and supramarginal gyrus, defined on the basis of anatomical landmarks and cytoarchitectural organization of neurons. However, it is not clear as to whether the three areas represent functional subregions within the IPL. For instance, imaging studies frequently identified clusters of activities that cut across areal boundaries. Here, we used resting-state functional magnetic resonance imaging (fMRI) data to examine how individual voxels within the IPL are best clustered according to their connectivity to the whole brain. The results identified a best estimate of seven clusters that are hierarchically arranged as the anterior, middle, and posterior subregions. The anterior, middle, and posterior IPL are each significantly connected to the somatomotor areas, superior/middle/inferior frontal gyri, and regions of the default mode network. This functional segregation is supported by recent cytoarchitechtonics and tractography studies. IPL showed hemispheric differences in connectivity that accord with a predominantly left parietal role in tool use and language processing and a right parietal role in spatial attention and mathematical cognition. The functional clusters may also provide a more parsimonious and perhaps even accurate account of regional activations of the IPL during a variety of cognitive challenges, as reported in earlier fMRI studies. PMID:24308753

The Influence of Frontal Lobe Tumors and Surgical Treatment on Advanced Cognitive Functions.

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Fang, Shengyu; Wang, Yinyan; Jiang, Tao

2016-07-01

Brain cognitive functions affect patient quality of life. The frontal lobe plays a crucial role in advanced cognitive functions, including executive function, meta-cognition, decision-making, memory, emotion, and language. Therefore, frontal tumors can lead to serious cognitive impairments. Currently, neurosurgical treatment is the primary method to treat brain tumors; however, the effects of the surgical treatments are difficult to predict or control. The treatment may both resolve the effects of the tumor to improve cognitive function or cause permanent disabilities resulting from damage to healthy functional brain tissue. Previous studies have focused on the influence of frontal lesions and surgical treatments on patient cognitive function. Here, we review cognitive impairment caused by frontal lobe brain tumors. Copyright © 2016 Elsevier Inc. All rights reserved.

Distributed patterns of occipito-parietal functional connectivity predict the precision of visual working memory.

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Galeano Weber, Elena M; Hahn, Tim; Hilger, Kirsten; Fiebach, Christian J

2017-02-01

Limitations in visual working memory (WM) quality (i.e., WM precision) may depend on perceptual and attentional limitations during stimulus encoding, thereby affecting WM capacity. WM encoding relies on the interaction between sensory processing systems and fronto-parietal 'control' regions, and differences in the quality of this interaction are a plausible source of individual differences in WM capacity. Accordingly, we hypothesized that the coupling between perceptual and attentional systems affects the quality of WM encoding. We combined fMRI connectivity analysis with behavioral modeling by fitting a variable precision and fixed capacity model to the performance data obtained while participants performed a visual delayed continuous response WM task. We quantified functional connectivity during WM encoding between occipital and parietal brain regions activated during both perception and WM encoding, as determined using a conjunction of two independent experiments. The multivariate pattern of voxel-wise inter-areal functional connectivity significantly predicted WM performance, most specifically the mean of WM precision but not the individual number of items that could be stored in memory. In particular, higher occipito-parietal connectivity was associated with higher behavioral mean precision. These results are consistent with a network perspective of WM capacity, suggesting that the efficiency of information flow between perceptual and attentional neural systems is a critical determinant of limitations in WM quality. Copyright © 2016 Elsevier Inc. All rights reserved.

Altered Parietal Activation during Non-symbolic Number Comparison in Children with Prenatal Alcohol Exposure

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Keri J. Woods

2018-01-01

Full Text Available Number processing is a cognitive domain particularly sensitive to prenatal alcohol exposure, which relies on intact parietal functioning. Alcohol-related alterations in brain activation have been found in the parietal lobe during symbolic number processing. However, the effects of prenatal alcohol exposure on the neural correlates of non-symbolic number comparison and the numerical distance effect have not been investigated. Using functional magnetic resonance imaging (fMRI, we examined differences in brain activation associated with prenatal alcohol exposure in five parietal regions involved in number processing during a non-symbolic number comparison task with varying degrees of difficulty. fMRI results are presented for 27 Cape Colored children (6 fetal alcohol syndome (FAS/partial FAS, 5 heavily exposed (HE non-sydromal, 16 controls; mean age ± SD = 11.7 ± 1.1 years. Fetal alcohol exposure was assessed by interviewing mothers using a timeline follow-back approach. Separate subject analyses were performed in each of five regions of interest, bilateral horizontal intraparietal sulci (IPS, bilateral posterior superior parietal lobules (PSPL, and left angular gyrus (left AG, using the general linear model with predictors for number comparison and difficulty level. Mean percent signal change for each predictor was extracted for each subject for each region to examine group differences and associations with continuous measures of alcohol exposure. Although groups did not differ in performance, controls activated the right PSPL more during non-symbolic number comparison than exposed children, but this was not significant after controlling for maternal smoking, and the right IPS more than children with fetal alcohol syndrome (FAS or partial FAS. More heavily exposed children recruited the left AG to a greater extent as task difficulty increased, possibly to compensate, in part, for impairments in function in the PSPL and IPS. Notably, in non

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

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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

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

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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

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

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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

[Advances in research on cognitive function related to temporal lobe epilepsy: focus on social cognitive function].

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Yamano, Mitsuhiko; Akamatsu, Naoki; Tsuji, Sadatoshi

2012-09-01

Research on cognitive function related to temporal lobe epilepsy has thus far focused on memory, language, and general intelligence. Recently, however, the concept of social cognitive function has been proposed in the field of neuropsychology. Social cognitive function refers collectively to the higher cognitive functions that are essential in our social lives, and its representative aspects are facial expression recognition and decision-making. Emotional processing centered around the amygdala is thought to play a key role in the neural mechanism of this function. We conducted a study on the social cognitive function (decision-making) of patients with temporal lobe epilepsy, and found that this function is reduced in these patients, and that the right amygdalo-hippocampal complexes play an important role. In order to ensure the best possible treatment for epilepsy patients, it is necessary not only to make an accurate diagnosis and provide appropriate treatment, but also to provide support for enabling a smoother social life from the perspective of social cognitive function. Future research developments in this field are expected to contribute to total management in medical care for epilepsy patients.

Effects of post-traumatic stress disorder on occipital lobe function and structure.

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Chao, Linda L; Lenoci, Maryann; Neylan, Thomas C

2012-05-09

Although there is evidence for strong connectivity between the amygdala and the visual cortex and some evidence for reduced occipital lobe gray matter volume in patients with post-traumatic stress disorder (PTSD), few studies have directly examined the effects of PTSD on occipital function. The current study used functional and structural MRI to examine occipital cortex function and structure in male combat veterans with and without PTSD. Left occipital gray matter volume was reduced in PTSD patients relative to the controls and correlated negatively with the severity of PTSD symptoms. Functional activity in the lateral occipital complex to aversive and nonaversive pictures presented in novel and repeated presentations was not altered by PTSD. These findings suggest that PTSD adversely affects occipital lobe volume but not the reactivity of the lateral occipital complex to generally aversive, trauma nonspecific stimuli.

Modulation of Speech Motor Learning with Transcranial Direct Current Stimulation of the Inferior Parietal Lobe

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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

Memory Functions following Surgery for Temporal Lobe Epilepsy in Children

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Jambaque, Isabelle; Dellatolas, Georges; Fohlen, Martine; Bulteau, Christine; Watier, Laurence; Dorfmuller, Georg; Chiron, Catherine; Delalande, Olivier

2007-01-01

Surgical treatment appears to improve the cognitive prognosis in children undergoing surgery for temporal lobe epilepsy (TLE). The beneficial effects of surgery on memory functions, particularly on material-specific memory, are more difficult to assess because of potentially interacting factors such as age range, intellectual level,…

Let's inhibit our excitement: the relationships between Stroop, behavioral disinhibition, and the frontal lobes.

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Heflin, Lara H; Laluz, Victor; Jang, Jung; Ketelle, Robin; Miller, Bruce L; Kramer, Joel H

2011-09-01

The Stroop (Stroop, 1935) is a frequently used neuropsychological test, with poor performance typically interpreted as indicative of disinhibition and frontal lobe damage. This study tested those interpretations by examining relationships between Stroop performance, behavioral disinhibition, and frontal lobe atrophy. Participants were 112 patients with mild cognitive impairment or dementia, recruited through UCSF's Memory and Aging Center. Participants received comprehensive dementia evaluations including structural MRI, neuropsychological testing, and informant interviews. Freesurfer, a semiautomated parcellation program, was used to analyze 1.5T MRI scans. Behavioral disinhibition was measured using the Neuropsychiatric Inventory (Cummings, 1997; Cummings et al., 1994) Disinhibition Scale. The sample (n = 112) mean age was 65.40 (SD = 8.60) years, education was 16.64 (SD = 2.54) years, and Mini-Mental State Examination (MMSE; Folstein et al., 1975) was 26.63 (SD = 3.32). Hierarchical linear regressions were used for data analysis. Controlling for age, MMSE, and color naming, Stroop performance was not significantly associated with disinhibition (β = 0.01, ΔR² = 0.01, p = .29). Hierarchical regressions controlling for age, MMSE, color naming, intracranial volume, and temporal and parietal lobes, examined whether left or right hemisphere regions predict Stroop performance. Bilaterally, parietal lobe atrophy best predicted poorer Stroop (left: β = 0.0004, ΔR² = 0.02, p = .002; right: β = 0.0004, ΔR² = 0.02, p = .002). Of frontal regions, only dorsolateral prefrontal cortex atrophy predicted poorer Stroop (β = 0.001, ΔR² = 0.01, p = .03); left and right anterior cingulate cortex atrophy predicted better Stroop (left: β = -0.003, ΔR² = 0.01, p = .02; right: β = -0.004, ΔR² = 0.01, p = .02). These findings suggest Stroop performance is a poor measure of behavioral disinhibition and frontal lobe atrophy even among a relatively high-risk population

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

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

Relationship between cortical resection and visual function after occipital lobe epilepsy surgery.

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Heo, Won; Kim, June Sic; Chung, Chun Kee; Lee, Sang Kun

2017-10-27

OBJECTIVE In this study, the authors investigated long-term clinical and visual outcomes of patients after occipital lobe epilepsy (OLE) surgery and analyzed the relationship between visual cortical resection and visual function after OLE surgery. METHODS A total of 42 consecutive patients who were diagnosed with OLE and underwent occipital lobe resection between June 1995 and November 2013 were included. Clinical, radiological, and histopathological data were reviewed retrospectively. Seizure outcomes were categorized according to the Engel classification. Visual function after surgery was assessed using the National Eye Institute Visual Functioning Questionnaire 25. The relationship between the resected area of the visual cortex and visual function was demonstrated by multivariate linear regression models. RESULTS After a mean follow-up period of 102.2 months, 27 (64.3%) patients were seizure free, and 6 (14.3%) patients had an Engel Class II outcome. Nineteen (57.6%) of 33 patients had a normal visual field or quadrantanopia after surgery (normal and quadrantanopia groups). Patients in the normal and quadrantanopia groups had better vision-related quality of life than those in the hemianopsia group. The resection of lateral occipital areas 1 and 2 of the occipital lobe was significantly associated with difficulties in general vision, peripheral vision, and vision-specific roles. In addition, the resection of intraparietal sulcus 3 or 4 was significantly associated with decreased social functioning. CONCLUSIONS The authors found a favorable seizure control rate (Engel Class I or II) of 78.6%, and 57.6% of the subjects had good visual function (normal vision or quadrantanopia) after OLE surgery. Lateral occipital cortical resection had a significant effect on visual function despite preservation of the visual field.

OCCIPITAL LOBE SYNDROME

OpenAIRE

Shahdevi Nandar Kurniawan

2016-01-01

The ability to recognize objects and words is not just depend on the integrity of visual pathway and primary vision area on cerebral cortex (Brodmann area 17), but also secondary vision area 18 and tertiary vision area 19 on occipital lobe. Lesion in occipital lobe could disturb of human visual function such as visual field defects, inability to recognize colors, inability to recognize words, visual hallucinations and illusions, occipital lobe epilepsy, and Anton’s syndrome. Some causes of oc...

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.

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.

Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

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Maeshima, S.; Matsumoto, T.; Ueyoshi, A.; Toshiro, H.; Sekiguchi, E.; Okita, R.; Yamaga, H.; Ozaki, F.; Moriwaki, H.; Roger, P.

2002-01-01

We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

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Maeshima, S.; Matsumoto, T.; Ueyoshi, A. [Department of Physical Medicine and Rehabilitation, Wakayama Medical University, Wakayama (Japan); Toshiro, H.; Sekiguchi, E.; Okita, R.; Yamaga, H.; Ozaki, F.; Moriwaki, H. [Department of Neurological Surgery, Hidaka General Hospital, Wakayama (Japan); Roger, P. [School of Communication Sciences and Disorders, University of Sydney, Sydney, NSW (Australia)

2002-02-01

We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

Correlation of neuropsychological and metabolic changes after epilepsy surgery in patients with left mesial temporal lobe epilepsy with hippocampal sclerosis.

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Güvenç, Canan; Dupont, Patrick; Van den Stock, Jan; Seynaeve, Laura; Porke, Kathleen; Dries, Eva; Van Bouwel, Karen; van Loon, Johannes; Theys, Tom; Goffin, Karolien E; Van Paesschen, Wim

2018-04-12

Epilepsy surgery often causes changes in cognition and cerebral glucose metabolism. Our aim was to explore relationships between pre- and postoperative cerebral metabolism as measured with 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) and neuropsychological test scores in patients with left mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS), who were rendered seizure-free after epilepsy surgery. Thirteen patients were included. All had neuropsychological testing and an interictal FDG-PET scan of the brain pre- and postoperative. Correlations between changes in neuropsychological test scores and metabolism were examined using statistical parametric mapping (SPM). There were no significant changes in the neuropsychological test scores pre- and postoperatively at the group level. Decreased metabolism was observed in the left mesial temporal regions and occipital lobe. Increased metabolism was observed in the bi-frontal and right parietal lobes, temporal lobes, occipital lobes, thalamus, cerebellum, and vermis. In these regions, we did not find a correlation between changes in metabolism and neuropsychological test scores. A significant negative correlation, however, was found between metabolic changes in the precuneus and Boston Naming Test (BNT) scores. There are significant metabolic decreases in the left mesial temporal regions and increases in the bi-frontal lobes; right parietal, temporal, and occipital lobes; right thalamus; cerebellum; and vermis in patients with left MTLE-HS who were rendered seizure-free after epilepsy surgery. We could not confirm that these changes translate into significant cognitive changes. A significant negative correlation was found between changes in confrontation naming and changes in metabolism in the precuneus. We speculate that the precuneus may play a compensatory role in patients with postoperative naming difficulties after left TLE surgery. Understanding of these neural mechanisms may aid in

Analysis of cognitive function and regional cerebral blood flow in Parkinson's disease by 123I-IMP SPECT

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Yamamoto, Kiyoshi

1992-01-01

To investigate the relationship between alterations of regional cerebral blood flow (rCBF) and cognitive impairment in parkinsonian patients, I studied 41 patients with Parkinson's disease (19 men and 22 women) using single photon emission computed tomography (SPECT) with N-isopropyl-p-[ 123 I]iodoamphetamine ( 123 I-IMP). I evaluated cognitive function with the Mini-Mental State examination (MMS), the Hasegawa's Dementia Scale (HDS), the Kana-pick up test (KT), and the figure drawing test (FDT). I evaluated motor impairment with the Hoehn and Yahr stage. SPECT scanning was performed with a rotating digital gamma camera TOSHIBA 901-A. A semiquantitative method of assessing regional tracer uptake was used. Regions of interest (ROI: 3x3 pixels, 15.9x15.9 mm 2 ) were drawn on the cerebellar hemispheres, cortical regions (frontal, temporal, parietal and occipital), and basal ganglia bilaterally. The RI count index was expressed as a ratio of activity in each ROI to mean counting rate over cerebellar regions. I considered the RI count index as the index of rCBF in each ROI. There were strong positive correlations between MMS and rCBF of frontal, parietal and occipital lobes (p<0.001). There were positive correlations between HDS and rCBF of frontal (p<0.01), parietal (p<0.001) and occipital lobes (p<0.01). There were positive correlations between KT and rCBF of frontal (p<0.01) and occipital (p<0.05) lobes. There were no correlations between FDT and rCBF. There were negative correlations between the Hoehn and Yahr stage and MMS (p<0.001), HDS (p<0.001), KT (p<0.001) and FDT (p<0.05). There seemed to be a relationship between cognitive function and rCBF of frontal, parietal and occipital cortex, between motor impairment and rCBF of frontal lobe and between cognitive and motor impairments in parkinsonian patients. These findings suggest that intellectual deterioration in Parkinson's disease may be caused by a specific mechanism different from Alzheimer's disease. (author)

Improved Cerebral Function in Mesial Temporal Lobe Epilepsy after Subtemporal Amygdalohippocampectomy

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Takaya, Shigetoshi; Mikuni, Nobuhiro; Mitsueda, Takahiro; Satow, Takeshi; Taki, Junya; Kinoshita, Masako; Miyamoto, Susumu; Hashimoto, Nobuo; Ikeda, Akio; Fukuyama, Hidenao

2009-01-01

The functional changes that occur throughout the human brain after the selective removal of an epileptogenic lesion remain unclear. Subtemporal selective amygdalohippocampectomy (SAH) has been advocated as a minimally invasive surgical procedure for patients with medically intractable mesial temporal lobe epilepsy (MTLE). We evaluated the effects…

Analysis of cognitive function and regional cerebral blood flow in Parkinson's disease by sup 123 I-IMP SPECT

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Yamamoto, Kiyoshi [Yamaguchi Univ., Ube (Japan). School of Medicine

1992-01-01

To investigate the relationship between alterations of regional cerebral blood flow (rCBF) and cognitive impairment in parkinsonian patients, I studied 41 patients with Parkinson's disease (19 men and 22 women) using single photon emission computed tomography (SPECT) with N-isopropyl-p-({sup 123}I)iodoamphetamine ({sup 123}I-IMP). I evaluated cognitive function with the Mini-Mental State examination (MMS), the Hasegawa's Dementia Scale (HDS), the Kana-pick up test (KT), and the figure drawing test (FDT). I evaluated motor impairment with the Hoehn and Yahr stage. SPECT scanning was performed with a rotating digital gamma camera TOSHIBA 901-A. A semiquantitative method of assessing regional tracer uptake was used. Regions of interest (ROI: 3x3 pixels, 15.9x15.9 mm{sup 2}) were drawn on the cerebellar hemispheres, cortical regions (frontal, temporal, parietal and occipital), and basal ganglia bilaterally. The RI count index was expressed as a ratio of activity in each ROI to mean counting rate over cerebellar regions. I considered the RI count index as the index of rCBF in each ROI. There were strong positive correlations between MMS and rCBF of frontal, parietal and occipital lobes (p<0.001). There were positive correlations between HDS and rCBF of frontal (p<0.01), parietal (p<0.001) and occipital lobes (p<0.01). There were positive correlations between KT and rCBF of frontal (p<0.01) and occipital (p<0.05) lobes. There were no correlations between FDT and rCBF. There were negative correlations between the Hoehn and Yahr stage and MMS (p<0.001), HDS (p<0.001), KT (p<0.001) and FDT (p<0.05). There seemed to be a relationship between cognitive function and rCBF of frontal, parietal and occipital cortex, between motor impairment and rCBF of frontal lobe and between cognitive and motor impairments in parkinsonian patients. (author).

The relationship between theory of mind and the executive functions: Evidence from patients with frontal lobe damage.

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Yeh, Zai-Ting; Tsai, Ming-Cheng; Tsai, Ming-Dar; Lo, Chiao-Yu; Wang, Kaw-Chen

2017-01-01

"Theory of mind" (ToM) refers to the ability to predict others' thoughts, intentions, beliefs, and feelings. Evidence from neuropsychology and functional imaging indicates that ToM is a domain-specific or modular architecture; however, research in development psychology has suggested that ToM is the full development of the executive functions in individuals. Therefore, the relationship between ToM and the executive functions needs to be clarified. Since the frontal lobe plays a critical role in the abilities of ToM and the executive functions, patients with frontal lobe damage were recruited for the present study. Assessments of ToM and the executive functions were performed on 23 patients with frontal lobe damage and 20 healthy controls. When controlling for the executive functions, significant differences between the patient and normal groups were found in the affective component of ToM, but not in the cognitive component. The present study suggests that in various social situations, executing ToM abilities requires logical reasoning processes provided by the executive functions. However, the reasoning processes of affective ToM are independent of executive functions.

Increase in left liver lobe function after preoperative right portal vein embolisation assessed with gadolinium-EOB-DTPA MRI.

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Geisel, Dominik; Lüdemann, Lutz; Keuchel, Thomas; Malinowski, Maciej; Seehofer, Daniel; Stockmann, Martin; Hamm, Bernd; Gebauer, Bernhard; Denecke, Timm

2013-09-01

To prospectively evaluate the early development of regional liver function after right portal vein embolisation (PVE) with Gd-EOB-DTPA-enhanced MRI in patients scheduled for extended right hemihepatectomy. Ten patients who received a PVE before an extended hemihepatectomy were examined before and 14 days after PVE using Gd-EOB-DTPA-enhanced MRI of the liver. In these sequences representative region of interest measurements were performed in the embolised right (RLL) and the non-embolised left liver lobe (LLL). The volume as well as hepatic uptake index (HUI) was calculated independently for each lobe. Relative enhancement 14 days after PVE decreased in the RLL and increased significantly in the LLL (P DTPA-enhanced MRI, which could reflect the redirected portal venous blood flow and the rapid utilisation of a hepatic functional reserve. • Preoperative portal vein embolisation (PVE) is widely performed before right-sided hepatic resection. • PVE increases intravenous contrast medium uptake in the left lobe of liver. • The hepatic uptake index for the left liver lobe increases rapidly after PVE. • Left liver lobe function increase may be visualised by Gd-EOB-DTPA-enhanced MRI.

Imaging structural and functional brain networks in temporal lobe epilepsy

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Bernhardt, Boris C.; Hong, SeokJun; Bernasconi, Andrea; Bernasconi, Neda

2013-01-01

Early imaging studies in temporal lobe epilepsy (TLE) focused on the search for mesial temporal sclerosis, as its surgical removal results in clinically meaningful improvement in about 70% of patients. Nevertheless, a considerable subgroup of patients continues to suffer from post-operative seizures. Although the reasons for surgical failure are not fully understood, electrophysiological and imaging data suggest that anomalies extending beyond the temporal lobe may have negative impact on outcome. This hypothesis has revived the concept of human epilepsy as a disorder of distributed brain networks. Recent methodological advances in non-invasive neuroimaging have led to quantify structural and functional networks in vivo. While structural networks can be inferred from diffusion MRI tractography and inter-regional covariance patterns of structural measures such as cortical thickness, functional connectivity is generally computed based on statistical dependencies of neurophysiological time-series, measured through functional MRI or electroencephalographic techniques. This review considers the application of advanced analytical methods in structural and functional connectivity analyses in TLE. We will specifically highlight findings from graph-theoretical analysis that allow assessing the topological organization of brain networks. These studies have provided compelling evidence that TLE is a system disorder with profound alterations in local and distributed networks. In addition, there is emerging evidence for the utility of network properties as clinical diagnostic markers. Nowadays, a network perspective is considered to be essential to the understanding of the development, progression, and management of epilepsy. PMID:24098281

Imaging structural and functional brain networks in temporal lobe epilepsy.

Science.gov (United States)

Bernhardt, Boris C; Hong, Seokjun; Bernasconi, Andrea; Bernasconi, Neda

2013-10-01

Early imaging studies in temporal lobe epilepsy (TLE) focused on the search for mesial temporal sclerosis, as its surgical removal results in clinically meaningful improvement in about 70% of patients. Nevertheless, a considerable subgroup of patients continues to suffer from post-operative seizures. Although the reasons for surgical failure are not fully understood, electrophysiological and imaging data suggest that anomalies extending beyond the temporal lobe may have negative impact on outcome. This hypothesis has revived the concept of human epilepsy as a disorder of distributed brain networks. Recent methodological advances in non-invasive neuroimaging have led to quantify structural and functional networks in vivo. While structural networks can be inferred from diffusion MRI tractography and inter-regional covariance patterns of structural measures such as cortical thickness, functional connectivity is generally computed based on statistical dependencies of neurophysiological time-series, measured through functional MRI or electroencephalographic techniques. This review considers the application of advanced analytical methods in structural and functional connectivity analyses in TLE. We will specifically highlight findings from graph-theoretical analysis that allow assessing the topological organization of brain networks. These studies have provided compelling evidence that TLE is a system disorder with profound alterations in local and distributed networks. In addition, there is emerging evidence for the utility of network properties as clinical diagnostic markers. Nowadays, a network perspective is considered to be essential to the understanding of the development, progression, and management of epilepsy.

Imaging structural and functional brain networks in temporal lobe epilepsy

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Boris eBernhardt

2013-10-01

Full Text Available Early imaging studies in temporal lobe epilepsy (TLE focused on the search for mesial temporal sclerosis, as its surgical removal results in clinically meaningful improvement in about 70% of patients. Nevertheless, a considerable subgroup of patients continues to suffer from post-operative seizures. Although the reasons for surgical failure are not fully understood, electrophysiological and imaging data suggest that anomalies extending beyond the temporal lobe may have negative impact on outcome. This hypothesis has revived the concept of human epilepsy as a disorder of distributed brain networks. Recent methodological advances in non-invasive neuroimaging have led to quantify structural and functional networks in vivo. While structural networks can be inferred from diffusion MRI tractography and inter-regional covariance patterns of structural measures such as cortical thickness, functional connectivity is generally computed based on statistical dependencies of neurophysiological time-series, measured through functional MRI or electroencephalographic techniques. This review considers the application of advanced analytical methods in structural and functional connectivity analyses in TLE. We will specifically highlight findings from graph-theoretical analysis that allow assessing topological organization of brain networks. These studies have provided compelling evidence that TLE is a system disorder with profound alterations in local and distributed networks. In addition, there is emerging evidence for the utility of network properties as clinical diagnostic markers. Nowadays, a network perspective is considered to be essential to the understanding of the development, progression, and management of epilepsy.

At the intersection of attention and memory: the mechanistic role of the posterior parietal lobe in working memory

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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

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.

Mesial temporal lobe epilepsy diminishes functional connectivity during emotion perception.

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Steiger, Bettina K; Muller, Angela M; Spirig, Esther; Toller, Gianina; Jokeit, Hennric

2017-08-01

Unilateral mesial temporal lobe epilepsy (MTLE) has been associated with impaired recognition of emotional facial expressions. Correspondingly, imaging studies showed decreased activity of the amygdala and cortical face processing regions in response to emotional faces. However, functional connectivity among regions involved in emotion perception has not been studied so far. To address this, we examined intrinsic functional connectivity (FC) modulated by the perception of dynamic fearful faces among the amygdala and limbic, frontal, temporal and brainstem regions. Regions of interest were identified in an activation analysis by presenting a block-design with dynamic fearful faces and dynamic landscapes to 15 healthy individuals. This led to 10 predominately right-hemispheric regions. Functional connectivity between these regions during the perception of fearful faces was examined in drug-refractory patients with left- (n=16) or right-sided (n=17) MTLE, epilepsy patients with extratemporal seizure onset (n=15) and a second group of 15 healthy controls. Healthy controls showed a widespread functional network modulated by the perception of fearful faces that encompassed bilateral amygdalae, limbic, cortical, subcortical and brainstem regions. In patients with left MTLE, a downsized network of frontal and temporal regions centered on the right amygdala was present. Patients with right MTLE showed almost no significant functional connectivity. A maintained network in the epilepsy control group indicates that findings in mesial temporal lobe epilepsy could not be explained by clinical factors such as seizures and antiepileptic medication. Functional networks underlying facial emotion perception are considerably changed in left and right MTLE. Alterations are present for both hemispheres in either MTLE group, but are more pronounced in right MTLE. Disruption of the functional network architecture possibly contributes to deficits in facial emotion recognition frequently

Memory Functioning in Children with Epilepsy: Frontal Lobe Epilepsy, Childhood Absence Epilepsy, and Benign Epilepsy with Centrotemporal Spikes

OpenAIRE

Lopes, Ana Filipa; Monteiro, José Paulo; Fonseca, Maria José; Robalo, Conceição; Simões, Mário Rodrigues

2014-01-01

Specific cognitive deficits have been identified in children with epilepsy irrespective of results on intelligence tests. Memory deficits are traditionally attributed to temporal lobe epilepsy, whereas the impact of frontal lobe epilepsy on memory functions has remained controversial. The aim of this study was the examination of memory abilities in other childhood common epilepsy syndromes (frontal lobe epilepsy (FLE), childhood absence epilepsy (CAE), and benign epilepsy with centrotemporal ...

Differential Effect of Left vs. Right White Matter Hyperintensity Burden on Functional Decline: The Northern Manhattan Study.

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Dhamoon, Mandip S; Cheung, Ying-Kuen; Bagci, Ahmet; Alperin, Noam; Sacco, Ralph L; Elkind, Mitchell S V; Wright, Clinton B

2017-01-01

Asymmetry of brain dysfunction may disrupt brain network efficiency. We hypothesized that greater left-right white matter hyperintensity volume (WMHV) asymmetry was associated with functional trajectories. Methods: In the Northern Manhattan Study, participants underwent brain MRI with axial T1, T2, and fluid attenuated inversion recovery sequences, with baseline interview and examination. Volumetric WMHV distribution across 14 brain regions was determined separately by combining bimodal image intensity distribution and atlas based methods. Participants had annual functional assessments with the Barthel index (BI, range 0-100) over a mean of 7.3 years. Generalized estimating equations (GEE) models estimated associations of regional WMHV and regional left-right asymmetry with baseline BI and change over time, adjusted for baseline medical risk factors, sociodemographics, and cognition, and stroke and myocardial infarction during follow-up. Results: Among 1,195 participants, greater WMHV asymmetry in the parietal lobes (-8.46 BI points per unit greater WMHV on the right compared to left, 95% CI -3.07, -13.86) and temporal lobes (-2.48 BI points, 95% CI -1.04, -3.93) was associated with lower overall function. Greater WMHV asymmetry in the parietal lobes (-1.09 additional BI points per year per unit greater WMHV on the left compared to right, 95% CI -1.89, -0.28) was independently associated with accelerated functional decline. Conclusions: In this large population-based study with long-term repeated measures of function, greater regional WMHV asymmetry was associated with lower function and functional decline. In addition to global WMHV, WHMV asymmetry may be an important predictor of long-term functional status.

Clinical-physiologic correlates of Alzheimer's disease and frontal lobe dementia

International Nuclear Information System (INIS)

Jagust, W.J.; Reed, B.R.; Seab, J.P.; Kramer, J.H.; Budinger, T.F.

1989-01-01

Thirty patients with degenerative dementia underwent clinical evaluation, neuropsychological testing, and single photon emission computed tomography (SPECT) with the blood flow tracer [ 123 I]-N-isopropyl-p-iodoamphetamine. Five of these patients were clinically and psychologically different from the others, demonstrating predominant behavioral disturbances with relative preservation of memory function. These five patients, who were felt to have a frontal lobe dementia (FLD), showed SPECT perfusion patterns which differed from the remaining 25 patients, who were diagnosed as having Alzheimer's disease (AD), and from 16 healthy control subjects. The FLD patients showed diminished perfusion in orbitofrontal, dorsolateral frontal, and temporal cortex relative to controls, while the AD patients showed lower perfusion in temporal and parietal cortex than controls. The FLD patients also showed hypoperfusion in both frontal cortical regions relative to AD patients. The pattern of performance on neuropsychological testing paralleled these differences in regional perfusion. These results suggest that clinical evaluation and physiological imaging may enable the differentiation of groups of degenerative dementia patients during life

Investigating the Functional Utility of the Left Parietal ERP Old/New Effect: Brain Activity Predicts within But Not between Participant Variance in Episodic Recollection

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Catherine A. MacLeod

2017-12-01

Full Text Available A success story within neuroimaging has been the discovery of distinct neural correlates of episodic retrieval, providing insight into the processes that support memory for past life events. Here we focus on one commonly reported neural correlate, the left parietal old/new effect, a positive going modulation seen in event-related potential (ERP data that is widely considered to index episodic recollection. Substantial evidence links changes in the size of the left parietal effect to changes in remembering, but the precise functional utility of the effect remains unclear. Here, using forced choice recognition of verbal stimuli, we present a novel population level test of the hypothesis that the magnitude of the left parietal effect correlates with memory performance. We recorded ERPs during old/new recognition, source accuracy and Remember/Know/Guess tasks in two large samples of healthy young adults, and successfully replicated existing within participant modulations of the magnitude of the left parietal effect with recollection. Critically, however, both datasets also show that across participants the magnitude of the left parietal effect does not correlate with behavioral measures of memory – including both subjective and objective estimates of recollection. We conclude that in these tasks, and across this healthy young adult population, the generators of the left parietal ERP effect do not index performance as expected. Taken together, these novel findings provide important constraints on the functional interpretation of the left parietal effect, suggesting that between group differences in the magnitude of old/new effects cannot always safely be used to infer differences in recollection.

The cognitive profile of occipital lobe epilepsy and the selective association of left temporal lobe hypometabolism with verbal memory impairment.

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Knopman, Alex A; Wong, Chong H; Stevenson, Richard J; Homewood, Judi; Mohamed, Armin; Somerville, Ernest; Eberl, Stefan; Wen, Lingfeng; Fulham, Michael; Bleasel, Andrew F

2014-08-01

We investigated the cognitive profile of structural occipital lobe epilepsy (OLE) and whether verbal memory impairment is selectively associated with left temporal lobe hypometabolism on [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET). Nine patients with OLE, ages 8-29 years, completed presurgical neuropsychological assessment. Composite measures were calculated for intelligence quotient (IQ), speed, attention, verbal memory, nonverbal memory, and executive functioning. In addition, the Wisconsin Card Sorting Test (WCST) was used as a specific measure of frontal lobe functioning. Presurgical FDG-PET was analyzed with statistical parametric mapping in 8 patients relative to 16 healthy volunteers. Mild impairments were evident for IQ, speed, attention, and executive functioning. Four patients demonstrated moderate or severe verbal memory impairment. Temporal lobe hypometabolism was found in seven of eight patients. Poorer verbal memory was associated with left temporal lobe hypometabolism (p = 0.002), which was stronger (p = 0.03 and p = 0.005, respectively) than the association of left temporal lobe hypometabolism with executive functioning or with performance on the WCST. OLE is associated with widespread cognitive comorbidity, suggesting cortical dysfunction beyond the occipital lobe. Verbal memory impairment is selectively associated with left temporal lobe hypometabolism in OLE, supporting a link between neuropsychological dysfunction and remote hypometabolism in focal epilepsy. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

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.

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

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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.

Abnormality of cerebral cortical glucose metabolism in temporal lobe epilepsy with cognitive function impairment

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Bang-Hung Yang; Tsung-Szu Yeh; Tung-Ping Su; Jyh-Cheng Chen; Ren-Shyan Liu

2004-01-01

Objective: People with epilepsy commonly report having problems with their memory. Many indicate that memory difficulties significantly hinder their functioning at work, in school, and at home. Besides, some studies have reported that memory performance as a prognostic factor is of most value in patients with risk of refractory epilepsy and when used in a multidisciplinary setting. However, the cerebral cortical areas involving memory impairment in epilepsy is still unknown. The purpose of this study was to access changes of cerebral glucose metabolism of epilepsy patients using [F-18] fluorodeoxyglucose positron emission tomography (FDG PET). Method: Nine temporal lobe epilepsy patients were studied. Each patient was confirmed with lesions in right mesial temporal lobe by MRI, PET and EEG. Serial cognition function tests were performed. Regional cerebral glucose metabolism (rCMRglc) was measured by PET at 45 minutes after injection of 370 MBq of FDG. Parametric images were generated by grand mean scaling each scan to 50. The images were then transformed into standard stereotactic space. Statistical parametric mapping (SPM2) was applied to find the correlations between verbal memory, figure memory, perception intelligent quotation (PIQ) and rCMRglc in epilepsy patients. The changes of rCMRglc were significant if corrected p value was less than 0.05. Results: There was no significant relationship between figure memory score and verbal memory score. FDG-PET scan showed changes of rCMRglc positive related with verbal memory score in precentral gyms of right frontal lobe (Brodmann area 4, corrected p < 0.001, voxel size 240) and cingulated gyms of right limbic lobe (Brodmann area 32, corrected p=0.002, voxel size 143). No negative relationship was demonstrable between verbal memory and rCMRglc in this study. Besides, significanfiy positive correlation between figure memory was shown in cuneus of right occipital lobe (Brodmann area 18, corrected p < 0.001, voxel size

A Combined Study of SLC6A15 Gene Polymorphism and the Resting-State Functional Magnetic Resonance Imaging in First-Episode Drug-Naive Major Depressive Disorder.

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Wang, Lijuan; Liu, Zhifen; Cao, Xiaohua; Li, Jianying; Zhang, Aixia; Sun, Ning; Yang, Chunxia; Zhang, Kerang

2017-09-01

The SLC6A15 gene has been identified as a novel candidate gene for major depressive disorder (MDD). However, the mechanism underlying the effects of how the SLC6A15 gene affects functional brain activity of patients with MDD remains unknown. In the present study, we investigated the effect of the SLC6A15 gene polymorphism, rs1545843, on resting-state brain function in MDD with the imaging genomic technology and the regional homogeneity (ReHo) method. Sixty-seven MDD patients and 44 healthy controls underwent functional magnetic resonance imaging scans and genotyping. The differences in ReHo between genotypes were initially tested using the student's t test. We then performed a 2 × 2 (genotypes × disease status) analysis of variance to identify the main effects of genotypes, disease status, and their interactions in MDD. MDD patients with A+ genotypes showed decreased ReHo in the medial cingulum compared with MDD patients with the GG genotype. This was in contrast to normal controls with A+ genotypes who showed increased ReHo in the posterior cingulum and the frontal, temporal, and parietal lobes and decreased ReHo in the left corpus callosum, compared with controls with the GG genotypes. The main effect of disease was found in the frontal, parietal, and temporal lobes. The main effect of genotypes was found in the left corpus callosum and the frontal lobe. There was no interaction between rs1545843 genotypes and disease status. We found that the left corpus callosum ReHo was positively correlated with total scores of the Hamilton Depression Scale (HAMD) (p = 0.021), so as was the left inferior parietal gyrus ReHo with cognitive disorder (p = 0.02). In addition, the right middle temporal gyrus had a negative correlation with retardation (p = 0.049). We observed an association between the SLC6A15 rs1545843 and resting-state brain function of the corpus callosum, cingulum and the frontal, parietal, and temporal lobes in MDD patients, which may be

Altered brain function in new onset childhood acute lymphoblastic leukemia before chemotherapy: A resting-state fMRI study.

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Hu, Zhanqi; Zou, Dongfang; Mai, Huirong; Yuan, Xiuli; Wang, Lihong; Li, Yue; Liao, Jianxiang; Liu, Liwei; Liu, Guosheng; Zeng, Hongwu; Wen, Feiqiu

2017-10-01

Cognitive impairments had been reported in childhood acute lymphoblastic leukemia, what caused the impairments needed to be demonstrated, chemotherapy-related or the disease itself. The primary aim of this exploratory investigation was to determine if there were changes in brain function of children with acute lymphoblastic leukemia before chemotherapy. In this study, we advanced a measure named regional homogeneity to evaluate the resting-state brain activities, intelligence quotient test was performed at same time. Using regional homogeneity, we first investigated the resting state brain function in patients with new onset childhood acute lymphoblastic leukemia before chemotherapy, healthy children as control. The decreased ReHo values were mainly founded in the default mode network and left frontal lobe, bilateral inferior parietal lobule, bilateral temporal lobe, bilateral occipital lobe, precentral gyrus, bilateral cerebellum in the newly diagnosed acute lymphoblastic leukemia patients compared with the healthy control. While in contrast, increased ReHo values were mainly shown in the right frontal lobe (language area), superior frontal gyrus-R, middle frontal gyrus-R and inferior parietal lobule-R for acute lymphoblastic leukemia patients group. There were no significant differences for intelligence quotient measurements between the acute lymphoblastic leukemia patient group and the healthy control in performance intelligence quotient, verbal intelligence quotient, total intelligence quotient. The altered brain functions are associated with cognitive change and language, it is suggested that there may be cognition impairment before the chemotherapy. Regional homogeneity by functional magnetic resonance image is a sensitive way for early detection on brain damage in childhood acute lymphoblastic leukemia. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Task activation and functional connectivity show concordant memory laterality in temporal lobe epilepsy.

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Sideman, Noah; Chaitanya, Ganne; He, Xiaosong; Doucet, Gaelle; Kim, Na Young; Sperling, Michael R; Sharan, Ashwini D; Tracy, Joseph I

2018-04-01

In epilepsy, asymmetries in the organization of mesial temporal lobe (MTL) functions help determine the cognitive risk associated with procedures such as anterior temporal lobectomy. Past studies have investigated the change/shift in a visual episodic memory laterality index (LI) in mesial temporal lobe structures through functional magnetic resonance imaging (fMRI) task activations. Here, we examine whether underlying task-related functional connectivity (FC) is concordant with such standard fMRI laterality measures. A total of 56 patients with temporal lobe epilepsy (TLE) (Left TLE [LTLE]: 31; Right TLE [RTLE]: 25) and 34 matched healthy controls (HC) underwent fMRI scanning during performance of a scene encoding task (SET). We assessed an activation-based LI of the hippocampal gyrus (HG) and parahippocampal gyrus (PHG) during the SET and its correspondence with task-related FC measures. Analyses involving the HG and PHG showed that the patients with LTLE had a consistently higher LI (right-lateralized) than that of the HC and group with RTLE, indicating functional reorganization. The patients with RTLE did not display a reliable contralateral shift away from the pathology, with the mesial structures showing quite distinct laterality patterns (HG, no laterality bias; PHG, no evidence of LI shift). The FC data for the group with LTLE provided confirmation of reorganization effects, revealing that a rightward task LI may be based on underlying connections between several left-sided regions (middle/superior occipital and left medial frontal gyri) and the right PHG. The FCs between the right HG and left anterior cingulate/medial frontal gyri were also observed in LTLE. Importantly, the data demonstrate that the areas involved in the LTLE task activation shift to the right hemisphere showed a corresponding increase in task-related FCs between the hemispheres. Altered laterality patterns based on mesial temporal lobe epilepsy (MTLE) pathology manifest as several

Convergent Findings of Altered Functional and Structural Brain Connectivity in Individuals with High Functioning Autism: A Multimodal MRI Study.

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Sophia Mueller

Full Text Available Brain tissue changes in autism spectrum disorders seem to be rather subtle and widespread than anatomically distinct. Therefore a multimodal, whole brain imaging technique appears to be an appropriate approach to investigate whether alterations in white and gray matter integrity relate to consistent changes in functional resting state connectivity in individuals with high functioning autism (HFA. We applied diffusion tensor imaging (DTI, voxel-based morphometry (VBM and resting state functional connectivity magnetic resonance imaging (fcMRI to assess differences in brain structure and function between 12 individuals with HFA (mean age 35.5, SD 11.4, 9 male and 12 healthy controls (mean age 33.3, SD 9.0, 8 male. Psychological measures of empathy and emotionality were obtained and correlated with the most significant DTI, VBM and fcMRI findings. We found three regions of convergent structural and functional differences between HFA participants and controls. The right temporo-parietal junction area and the left frontal lobe showed decreased fractional anisotropy (FA values along with decreased functional connectivity and a trend towards decreased gray matter volume. The bilateral superior temporal gyrus displayed significantly decreased functional connectivity that was accompanied by the strongest trend of gray matter volume decrease in the temporal lobe of HFA individuals. FA decrease in the right temporo-parietal region was correlated with psychological measurements of decreased emotionality. In conclusion, our results indicate common sites of structural and functional alterations in higher order association cortex areas and may therefore provide multimodal imaging support to the long-standing hypothesis of autism as a disorder of impaired higher-order multisensory integration.

Parietal and temporal activity during a multimodal dance video game: an fNIRS study.

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Tachibana, Atsumichi; Noah, J Adam; Bronner, Shaw; Ono, Yumie; Onozuka, Minoru

2011-10-03

Using functional near infrared spectroscopy (fNIRS) we studied how playing a dance video game employs coordinated activation of sensory-motor integration centers of the superior parietal lobe (SPL) and superior temporal gyrus (STG). Subjects played a dance video game, in a block design with 30s of activity alternating with 30s of rest, while changes in oxy-hemoglobin (oxy-Hb) levels were continuously measured. The game was modified to compare difficult (4-arrow), simple (2-arrow), and stepping conditions. Oxy-Hb levels were greatest with increased task difficulty. The quick-onset, trapezoidal time-course increase in SPL oxy-Hb levels reflected the on-off neuronal response of spatial orienting and rhythmic motor timing that were required during the activity. Slow-onset, bell-shaped increases in oxy-Hb levels observed in STG suggested the gradually increasing load of directing multisensory information to downstream processing centers associated with motor behavior and control. Differences in temporal relationships of SPL and STG oxy-Hb concentration levels may reflect the functional roles of these brain structures during the task period. NIRS permits insights into temporal relationships of cortical hemodynamics during real motor tasks. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Altered pattern of spontaneous brain activity in the patients with end-stage renal disease: a resting-state functional MRI study with regional homogeneity analysis.

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Xue Liang

Full Text Available PURPOSE: To investigate the pattern of spontaneous neural activity in patients with end-stage renal disease (ESRD with and without neurocognitive dysfunction using resting-state functional magnetic resonance imaging (rs-fMRI with a regional homogeneity (ReHo algorithm. MATERIALS AND METHODS: rs-fMRI data were acquired in 36 ESRD patients (minimal nephro-encephalopathy [MNE], n = 19, 13 male, 37±12.07 years; non-nephro-encephalopathy [non-NE], n = 17, 11 male, 38±12.13 years and 20 healthy controls (13 male, 7 female, 36±10.27 years. Neuropsychological (number connection test type A [NCT-A], digit symbol test [DST] and laboratory tests were performed in all patients. The Kendall's coefficient of concordance (KCC was used to measure the regional homogeneity for each subject. The regional homogeneity maps were compared using ANOVA tests among MNE, non-NE, and healthy control groups and post hoc t -tests between each pair in a voxel-wise way. A multiple regression analysis was performed to evaluate the relationships between ReHo index and NCT-A, DST scores, serum creatinine and urea levels, disease and dialysis duration. RESULTS: Compared with healthy controls, both MNE and non-NE patients showed decreased ReHo in the multiple areas of bilateral frontal, parietal and temporal lobes. Compared with the non-NE, MNE patients showed decreased ReHo in the right inferior parietal lobe (IPL, medial frontal cortex (MFC and left precuneus (PCu. The NCT-A scores and serum urea levels of ESRD patients negatively correlated with ReHo values in the frontal and parietal lobes, while DST scores positively correlated with ReHo values in the bilateral PCC/precuneus, MFC and inferior parietal lobe (IPL (all P0.05, AlphaSim corrected. CONCLUSION: Diffused decreased ReHo values were found in both MNE and non-NE patients. The progressively decreased ReHo in the default mode network (DMN, frontal and parietal lobes might be trait-related in MNE. The Re

The functional neuroanatomy of language

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Hickok, Gregory

2009-09-01

There has been substantial progress over the last several years in understanding aspects of the functional neuroanatomy of language. Some of these advances are summarized in this review. It will be argued that recognizing speech sounds is carried out in the superior temporal lobe bilaterally, that the superior temporal sulcus bilaterally is involved in phonological-level aspects of this process, that the frontal/motor system is not central to speech recognition although it may modulate auditory perception of speech, that conceptual access mechanisms are likely located in the lateral posterior temporal lobe (middle and inferior temporal gyri), that speech production involves sensory-related systems in the posterior superior temporal lobe in the left hemisphere, that the interface between perceptual and motor systems is supported by a sensory-motor circuit for vocal tract actions (not dedicated to speech) that is very similar to sensory-motor circuits found in primate parietal lobe, and that verbal short-term memory can be understood as an emergent property of this sensory-motor circuit. These observations are considered within the context of a dual stream model of speech processing in which one pathway supports speech comprehension and the other supports sensory-motor integration. Additional topics of discussion include the functional organization of the planum temporale for spatial hearing and speech-related sensory-motor processes, the anatomical and functional basis of a form of acquired language disorder, conduction aphasia, the neural basis of vocabulary development, and sentence-level/grammatical processing.

Investigating the effects of nitrous oxide sedation on frontal-parietal interactions.

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Ryu, Ji-Ho; Kim, Pil-Jong; Kim, Hong-Gee; Koo, Yong-Seo; Shin, Teo Jeon

2017-06-09

Although functional connectivity has received considerable attention in the study of consciousness, few studies have investigated functional connectivity limited to the sedated state where consciousness is maintained but impaired. The aim of the present study was to investigate changes in functional connectivity of the parietal-frontal network resulting from nitrous oxide-induced sedation, and to determine the neural correlates of cognitive impairment during consciousness transition states. Electroencephalography was acquired from healthy adult patients who underwent nitrous oxide inhalation to induce cognitive impairment, and was analyzed using Granger causality (GC). Periods of awake, sedation and recovery for GC between frontal and parietal areas in the delta, theta, alpha, beta, gamma and total frequency bands were obtained. The Friedman test with post-hoc analysis was conducted for GC values of each period for comparison. As a sedated state was induced by nitrous oxide inhalation, power in the low frequency band showed increased activity in frontal regions that was reversed with discontinuation of nitrous oxide. Feedback and feedforward connections analyzed in spectral GC were changed differently in accordance with EEG frequency bands in the sedated state by nitrous oxide administration. Calculated spectral GC of the theta, alpha, and beta frequency regions in the parietal-to-frontal direction was significantly decreased in the sedated state while spectral GC in the reverse direction did not show significant change. Frontal-parietal functional connectivity is significantly affected by nitrous oxide inhalation. Significantly decreased parietal-to-frontal interaction may induce a sedated state. Copyright © 2017 Elsevier B.V. All rights reserved.

Differential Effect of Left vs. Right White Matter Hyperintensity Burden on Functional Decline: The Northern Manhattan Study

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Mandip S. Dhamoon

2017-09-01

Full Text Available Asymmetry of brain dysfunction may disrupt brain network efficiency. We hypothesized that greater left-right white matter hyperintensity volume (WMHV asymmetry was associated with functional trajectories.Methods: In the Northern Manhattan Study, participants underwent brain MRI with axial T1, T2, and fluid attenuated inversion recovery sequences, with baseline interview and examination. Volumetric WMHV distribution across 14 brain regions was determined separately by combining bimodal image intensity distribution and atlas based methods. Participants had annual functional assessments with the Barthel index (BI, range 0–100 over a mean of 7.3 years. Generalized estimating equations (GEE models estimated associations of regional WMHV and regional left-right asymmetry with baseline BI and change over time, adjusted for baseline medical risk factors, sociodemographics, and cognition, and stroke and myocardial infarction during follow-up.Results: Among 1,195 participants, greater WMHV asymmetry in the parietal lobes (−8.46 BI points per unit greater WMHV on the right compared to left, 95% CI −3.07, −13.86 and temporal lobes (−2.48 BI points, 95% CI −1.04, −3.93 was associated with lower overall function. Greater WMHV asymmetry in the parietal lobes (−1.09 additional BI points per year per unit greater WMHV on the left compared to right, 95% CI −1.89, −0.28 was independently associated with accelerated functional decline.Conclusions: In this large population-based study with long-term repeated measures of function, greater regional WMHV asymmetry was associated with lower function and functional decline. In addition to global WMHV, WHMV asymmetry may be an important predictor of long-term functional status.

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

Herpes zoster chronification to postherpetic neuralgia induces brain activity and grey matter volume change

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Cao, Song; Qin, Bangyong; Zhang, Yi; Yuan, Jie; Fu, Bao; Xie, Peng; Song, Ganjun; Li, Ying; Yu, Tian

2018-01-01

Objective: Herpes zoster (HZ) can develop into postherpetic neuralgia (PHN), which is a chronic neuropathic pain (NP). Whether the chronification from HZ to PHN induced brain functional or structural change is unknown and no study compared the changes of the same brains of patients who transited from HZ to PHN. We minimized individual differences and observed whether the chronification of HZ to PHN induces functional and pain duration dependent grey matter volume (GMV) change in HZ-PHN patients. Methods: To minimize individual differences induced error, we enrolled 12 patients with a transition from HZ to PHN. The functional and structural changes of their brains between the two states were identified with resting-state functional MRI (rs-fMRI) technique (i.e., the regional homogeneity (ReHo) and fractional aptitude of low-frequency fluctuation (fALFF) method) and the voxel based morphometry (VBM) technology respectively. The correlations between MRI parameters (i.e., ΔReHo, ΔfALFF and ΔVBM) and Δpain duration were analyzed too. Results: Compared with HZ brains, PHN brains exhibited abnormal ReHo, fALFF and VBM values in pain matrix (the frontal lobe, parietal lobe, thalamus, limbic lobe and cerebellum) as well as the occipital lobe and temporal lobe. Nevertheless, the activity of vast area of cerebellum and frontal lobe significantly increased while that of occipital lobe and limbic lobe showed apparent decrease when HZ developed to PHN. In addition, PHN brain showed decreased GMV in the frontal lobe, the parietal lobe and the occipital lobe but increased in the cerebellum and the temporal lobe. Correlation analyses showed that some of the ReHo, fALFF and VBM differential areas (such as the cerebellum posterior lobe, the thalamus extra-nuclear and the middle temporal gyrus) correlated well with Δpain duration. Conclusions: HZ chronification induced functional and structural change in cerebellum, occipital lobe, temporal lobe, parietal lobe and limbic lobe

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.

Does polycystic ovary syndrome affect cognition? A functional magnetic resonance imaging study exploring working memory.

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Soleman, Remi S; Kreukels, Baudewijntje P C; Veltman, Dick J; Cohen-Kettenis, Peggy T; Hompes, Peter G A; Drent, Madeleine L; Lambalk, Cornelis B

2016-05-01

To study effects of overexposure to androgens and subsequent antiandrogenic treatment on brain activity during working memory processes in women with polycystic ovary syndrome (PCOS). In this longitudinal study, working memory function was evaluated with the use of functional magnetic resonance imaging (MRI) in women with PCOS before and after antiandrogenic treatment. Department of reproductive medicine, university medical center. Fourteen women with PCOS and with hyperandrogenism and 20 healthy control women without any features of PCOS or other hormonal disorders. Antiandrogenic hormone treatment. Functional MRI response during a working memory task. At baseline women with PCOS showed more activation than the control group within the right superior parietal lobe and the inferior parietal lobe during task (all memory conditions). Task performance (speed and accuracy) did not differ between the groups. After antiandrogenic treatment the difference in overall brain activity between the groups disappeared and accuracy in the high memory load condition of the working memory task increased in women with PCOS. Women with PCOS may need additional neural resources during a working memory task compared with women without PCOS, suggesting less efficient executive functioning. This inefficiency may have effects on daily life functioning of women with PCOS. Antiandrogenic treatment appears to have a beneficial effect on this area of cognitive functioning. NTR2493. Copyright © 2016. Published by Elsevier Inc.

Memory Functioning in Children with Epilepsy: Frontal Lobe Epilepsy, Childhood Absence Epilepsy, and Benign Epilepsy with Centrotemporal Spikes

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Ana Filipa Lopes

2014-01-01

Full Text Available Specific cognitive deficits have been identified in children with epilepsy irrespective of results on intelligence tests. Memory deficits are traditionally attributed to temporal lobe epilepsy, whereas the impact of frontal lobe epilepsy on memory functions has remained controversial. The aim of this study was the examination of memory abilities in other childhood common epilepsy syndromes (frontal lobe epilepsy (FLE, childhood absence epilepsy (CAE, and benign epilepsy with centrotemporal spikes (BECTS and the influence of epilepsy-related variables. Memory was examined in 90 children with epilepsy (each epilepsy group consisted of 30 children, aged 6–15, and compared with 30 control children. Children with FLE showed significant deficits in verbal and visual memory. In addition, type of epilepsy, earlier age at epilepsy onset, and longer active duration of epilepsy were associated with memory problems. Seizure frequency and treatment, however, did not influence memory performance. This study indicates that children with FLE show greater risk of developing memory deficits than children with CAE or BECTS, thus highlighting the importance of assessing also memory functions in frontal lobe epilepsy.

Progressively Disrupted Intrinsic Functional Connectivity of Basolateral Amygdala in Very Early Alzheimer’s Disease

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Marion Ortner

2016-09-01

Full Text Available Abstract:Very early Alzheimer’s disease (AD - i.e., AD at stages of mild cognitive impairment (MCI and mild dementia - is characterized by progressive structural and neuropathologic changes such as atrophy or tangle deposition in medial temporal lobes, including hippocampus and entorhinal cortex but also adjacent amygdala. While progressively disrupted intrinsic connectivity of hippocampus with other brain areas has been demonstrated by many studies, amygdala connectivity was rarely investigated in AD, notwithstanding its known relevance for emotion processing and mood disturbances, which are both important in early AD. Intrinsic functional connectivity (iFC patterns of hippocampus and amygdala overlap in healthy persons. Thus, we hypothesized that increased alteration of iFC patterns along AD is not limited to the hippocampus but also concerns the amygdala, independent from atrophy. To address this hypothesis, we applied structural and functional resting-state MRI in healthy controls (CON, n=33 and patients with AD in the stages of MCI (AD-MCI, n=38 and mild dementia (AD-D, n=36. Outcome measures were voxel-based morphometry (VBM values and region of interest-based intrinsic functional connectivity maps (iFC of basolateral amygdala, which has extended cortical connectivity. Amygdala VBM values were progressively reduced in patients (CON > AD-MCI and AD-D. Amygdala iFC was progressively reduced along impairment severity (CON > AD-MCI > AD-D, particularly for hippocampus, temporal lobes, and fronto-parietal areas. Notably, decreased iFC was independent of amygdala atrophy. Results demonstrate progressively impaired amygdala intrinsic connectivity in temporal and fronto-parietal lobes independent from increasing amygdala atrophy in very early AD. Data suggest that early AD disrupts intrinsic connectivity of medial temporal lobe key regions including that of amygdala.

Clinical value of CT-based preoperative software assisted lung lobe volumetry for predicting postoperative pulmonary function after lung surgery

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Wormanns, Dag; Beyer, Florian; Hoffknecht, Petra; Dicken, Volker; Kuhnigk, Jan-Martin; Lange, Tobias; Thomas, Michael; Heindel, Walter

2005-04-01

This study was aimed to evaluate a morphology-based approach for prediction of postoperative forced expiratory volume in one second (FEV1) after lung resection from preoperative CT scans. Fifteen Patients with surgically treated (lobectomy or pneumonectomy) bronchogenic carcinoma were enrolled in the study. A preoperative chest CT and pulmonary function tests before and after surgery were performed. CT scans were analyzed by prototype software: automated segmentation and volumetry of lung lobes was performed with minimal user interaction. Determined volumes of different lung lobes were used to predict postoperative FEV1 as percentage of the preoperative values. Predicted FEV1 values were compared to the observed postoperative values as standard of reference. Patients underwent lobectomy in twelve cases (6 upper lobes; 1 middle lobe; 5 lower lobes; 6 right side; 6 left side) and pneumonectomy in three cases. Automated calculation of predicted postoperative lung function was successful in all cases. Predicted FEV1 ranged from 54% to 95% (mean 75% +/- 11%) of the preoperative values. Two cases with obviously erroneous LFT were excluded from analysis. Mean error of predicted FEV1 was 20 +/- 160 ml, indicating absence of systematic error; mean absolute error was 7.4 +/- 3.3% respective 137 +/- 77 ml/s. The 200 ml reproducibility criterion for FEV1 was met in 11 of 13 cases (85%). In conclusion, software-assisted prediction of postoperative lung function yielded a clinically acceptable agreement with the observed postoperative values. This method might add useful information for evaluation of functional operability of patients with lung cancer.

Functional anatomy of top-down visuospatial processing in the human brain : evidence from rTMS

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Aleman, A; Schutter, DJLG; Ramsey, NF; van Honk, J; Kessels, RPC; Hoogduin, JM; Postma, A; Kahn, RS; de Haan, EHF

The hypothesis was tested that visuospatial mental imagery relies on processing in the posterior parietal lobe. Using repetitive transcranial magnetic stimulation (rTMS) in a cross-over, sham-controlled design, we compared involvement of right posterior parietal cortex with primary visual cortex.

Functional development of fronto-striato-parietal networks associated with time perception

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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

Frontal lobe functioning during a simple response conflict task in first-episode psychosis and its relationship to treatment response.

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Shafritz, Keith M; Ikuta, Toshikazu; Greene, Allison; Robinson, Delbert G; Gallego, Juan; Lencz, Todd; DeRosse, Pamela; Kingsley, Peter B; Szeszko, Philip R

2018-05-09

Prior functional magnetic resonance imaging (fMRI) studies have investigated the neural mechanisms underlying cognitive control in patients with psychosis with findings of both hypo- and hyperfrontality. One factor that may contribute to inconsistent findings is the use of complex and polyfactorial tasks to investigate frontal lobe functioning. In the current study we employed a simple response conflict task during fMRI to examine differences in brain activation between patients experiencing their first-episode of psychosis (n = 33) and age- and sex-matched healthy volunteers (n = 33). We further investigated whether baseline brain activation among patients predicted changes in symptom severity and treatment response following 12 weeks of controlled antipsychotic treatment. During the task subjects were instructed to press a response button on the same side or opposite side of a circle that appeared on either side of a central fixation point. Imaging data revealed that for the contrast of opposite-side vs. same-side, patients showed significantly greater activation compared with healthy volunteers in the anterior cingulate cortex and intraparietal sulcus. Among patients, greater baseline anterior cingulate cortex, temporal-parietal junction, and superior temporal cortex activation predicted greater symptom reduction and therapeutic response following treatment. All findings remained significant after covarying for task performance. Intact performance on this relatively parsimonious task was associated with frontal hyperactivity suggesting the need for patients to utilize greater neural resources to achieve task performance comparable to healthy individuals. Moreover, frontal hyperactivity observed using a simple fMRI task may provide a biomarker for predicting treatment response in first-episode psychosis.

Confabulation and memory impairments following frontal lobe lesions

OpenAIRE

Turner, Martha

2005-01-01

Neuroimaging studies have provided considerable evidence for frontal lobe involvement in memory processing. Memory impairments arc also frequently reported in patients with frontal lobe lesions. However detailed anatomical localisation is rare, making integration of lesion and imaging findings difficult. An investigation of the functional and anatomical contributions of the frontal lobes to memory was conducted in 42 patients with frontal lobe lesions, examining memory processes identified in...

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.

Neuroanatomical Substrates of Executive Functions: Beyond Prefrontal Structures

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Bettcher, Brianne M.; Mungas, Dan; Patel, Nihar; Elofson, Jonathan; Dutt, Shubir; Wynn, Matthew; Watson, Christa L.; Stephens, Melanie; Walsh, Christine M.; Kramer, Joel H.

2016-01-01

Executive functions are often considered lynchpin “frontal lobe tasks”, despite accumulating evidence that a broad network of anterior and posterior brain structures supports them. Using a latent variable modeling approach, we assessed whether prefrontal grey matter volumes independently predict executive function performance when statistically differentiated from global atrophy and individual non-frontal lobar volume contributions. We further examined whether fronto-parietal white matter microstructure underlies and independently contributes to executive functions. We developed a latent variable model to decompose lobar grey matter volumes into a global grey matter factor and specific lobar volumes (i.e. prefrontal, parietal, temporal, occipital) that were independent of global grey matter. We then added mean fractional anisotropy (FA) for the superior longitudinal fasciculus (dorsal portion), corpus callosum, and cingulum bundle (dorsal portion) to models that included grey matter volumes related to cognitive variables in previous analyses. Results suggested that the 2-factor model (shifting/inhibition, updating/working memory) plus an information processing speed factor best explained our executive function data in a sample of 202 community dwelling older adults, and was selected as the base measurement model for further analyses. Global grey matter was related to the executive function and speed variables in all four lobar models, but independent contributions of the frontal lobes were not significant. In contrast, when assessing the effect of white matter microstructure, cingulum FA made significant independent contributions to all three executive function and speed variables and corpus callosum FA was independently related to shifting/inhibition and speed. Findings from the current study indicate that while prefrontal grey matter volumes are significantly associated with cognitive neuroscience measures of shifting/inhibition and working memory in healthy

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.

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.

Altered structural and functional thalamocortical networks in secondarily generalized extratemporal lobe seizures

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Syu-Jyun Peng

2017-01-01

Full Text Available Structural and functional abnormalities in the thalamocortical network in primary generalized epilepsies or mesial temporal lobe epilepsy have recently been identified by voxel-wise analyses of neuroimaging. However, evidence is needed regarding the profiles of the thalamocortical network in patients with secondarily generalized seizures from focal neocortical sources. We used high-resolution T1-weighted, diffusion-tensor and resting-state functional MR imaging (rs-fMRI to examine 16 patients with secondarily generalized extratemporal lobe seizures and 16 healthy controls. All the patients were medically effective and MRI-negative. Using whole brain voxel-based morphometry (VBM to compare the patients with the normal controls, we observed significantly decreased gray matter (GM density in the thalamus and 3 frontal gyri and significantly reduced white matter (WM fractional anisotropy (FA in the bilateral anterior corona radiata of the patients. Alterations in the thalamocortical functional connectivity with different cortices were identified by the rs-fMRI analysis seeding of the whole thalamus. The prefrontal gyri with the greatest functional connectivity were also traced by seeding a sub-thalamic region that is demarcated in an atlas, in which the thalamic parcellation is based on the WM connectivity to the cortices. This sub-thalamic region anatomically contains the mediodorsal thalamic nucleus where, concordantly, there was a significant decrease in thalamic GM density in the VBM study. In contrast to the negative correlation between the disease duration and reduced thalamic densities and subcortical FA values, the strength of the functional thalamocortical connectivity had a paradoxical correlation. Our results conclusively indicate that generalized seizures with a focal cortical source are associated with structural and functional alterations in the thalamocortical network.

Abnormal Functional Connectivity Density in Post-traumatic Stress Disorder.

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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.

Predicting oculomotor behaviour from correlated populations of posterior parietal neurons.

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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.

Hurst Exponent Analysis of Resting-State fMRI Signal Complexity across the Adult Lifespan

Directory of Open Access Journals (Sweden)

Jianxin Dong

2018-02-01

Full Text Available Exploring functional information among various brain regions across time enables understanding of healthy aging process and holds great promise for age-related brain disease diagnosis. This paper proposed a method to explore fractal complexity of the resting-state functional magnetic resonance imaging (rs-fMRI signal in the human brain across the adult lifespan using Hurst exponent (HE. We took advantage of the examined rs-fMRI data from 116 adults 19 to 85 years of age (44.3 ± 19.4 years, 49 females from NKI/Rockland sample. Region-wise and voxel-wise analyses were performed to investigate the effects of age, gender, and their interaction on complexity. In region-wise analysis, we found that the healthy aging is accompanied by a loss of complexity in frontal and parietal lobe and increased complexity in insula, limbic, and temporal lobe. Meanwhile, differences in HE between genders were found to be significant in parietal lobe (p = 0.04, corrected. However, there was no interaction between gender and age. In voxel-wise analysis, the significant complexity decrease with aging was found in frontal and parietal lobe, and complexity increase was found in insula, limbic lobe, occipital lobe, and temporal lobe with aging. Meanwhile, differences in HE between genders were found to be significant in frontal, parietal, and limbic lobe. Furthermore, we found age and sex interaction in right parahippocampal gyrus (p = 0.04, corrected. Our findings reveal HE variations of the rs-fMRI signal across the human adult lifespan and show that HE may serve as a new parameter to assess healthy aging process.

Temporal Lobe Seizure

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... functions, including having odd feelings — such as euphoria, deja vu or fear. Temporal lobe seizures are sometimes called ... sudden sense of unprovoked fear or joy A deja vu experience — a feeling that what's happening has happened ...

Statistical parametric mapping for analyzing interictal magnetoencephalography in patients with left frontal lobe epilepsy.

Science.gov (United States)

Zhu, Haitao; Zhu, Jinlong; Bao, Forrest Sheng; Liu, Hongyi; Zhu, Xuchuang; Wu, Ting; Yang, Lu; Zou, Yuanjie; Zhang, Rui; Zheng, Gang

2016-01-01

Frontal lobe epilepsy is a common epileptic disorder and is characterized by recurring seizures that arise in the frontal lobes. The purpose of this study is to identify the epileptogenic regions and other abnormal regions in patients with left frontal lobe epilepsy (LFLE) based on the magnetoencephalogram (MEG), and to understand the effects of clinical variables on brain activities in patients with LFLE. Fifteen patients with LFLE (23.20 ± 8.68 years, 6 female and 9 male) and 16 healthy controls (23.13 ± 7.66 years, 6 female and 10 male) were included in resting-stage MEG examinations. Epileptogenic regions of LFLE patients were confirmed by surgery. Regional brain activations were quantified using statistical parametric mapping (SPM). The correlation between the activations of the abnormal brain regions and the clinical seizure parameters were computed for LFLE patients. Brain activations of LFLE patients were significantly elevated in left superior/middle/inferior frontal gyri, postcentral gyrus, inferior temporal gyrus, insula, parahippocampal gyrus and amygdala, including the epileptogenic regions. Remarkable decreased activations were found mainly in the left parietal gyrus and precuneus. There is a positive correlation between the duration of the epilepsy (in month) and activations of the abnormal regions, while no relation was found between age of seizure onset (year), seizure frequency and the regions of the abnormal activity of the epileptic patients. Our findings suggest that the aberrant brain activities of LFLE patients were not restricted to the epileptogenic zones. Long duration of epilepsy might induce further functional damage in patients with LFLE. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Impact of emotional salience on episodic memory in attention-deficit/hyperactivity disorder: a functional magnetic resonance imaging study.

Science.gov (United States)

Krauel, Kerstin; Duzel, Emrah; Hinrichs, Hermann; Santel, Stephanie; Rellum, Thomas; Baving, Lioba

2007-06-15

Patients with attention-deficit/hyperactivity disorder (ADHD) show episodic memory deficits especially in complex memory tasks. We investigated the neural correlates of memory formation in ADHD and their modulation by stimulus salience. We recorded event-related functional magnetic resonance imaging during an episodic memory paradigm with neutral and emotional pictures in 12 male ADHD subjects and 12 healthy adolescents. Emotional salience did significantly augment memory performance in ADHD patients. Successful encoding of neutral pictures was associated with activation of the anterior cingulate cortex (ACC) in healthy adolescents but with activation of the superior parietal lobe (SPL) and precuneus in ADHD patients. Successful encoding of emotional pictures was associated with prefrontal and inferior temporal cortex activation in both groups. Healthy adolescents, moreover, showed deactivation in the inferior parietal lobe. From a pathophysiological point of view, the most striking functional differences between healthy adolescents and ADHD patients were in the ACC and SPL. We suggest that increased SPL activation in ADHD reflected attentional compensation for low ACC activation during the encoding of neutral pictures. The higher salience of emotional stimuli, in contrast, regulated the interplay between ACC and SPL in conjunction with improving memory to the level of healthy adolescents.

Developing a comprehensive presurgical functional MRI protocol for patients with intractable temporal lobe epilepsy: a pilot study

International Nuclear Information System (INIS)

Deblaere, K.; Vandemaele, P.; Achten, E.; Backes, W.H.; Hofman, P.; Wilmink, J.; Boon, P.A.; Vonck, K.; Boon, P.; Troost, J.; Vermeulen, J.; Aldenkamp, A.

2002-01-01

Our aim was to put together and test a comprehensive functional MRI (fMRI) protocol which could compete with the intracarotid amytal (IAT) or Wada test for the localisation of language and memory function in patients with intractable temporal lobe epilepsy. The protocol was designed to be performed in under 1 h on a standard 1.5 tesla imager. We used five paradigms to test nine healthy right-handed subjects: complex scene-encoding, picture-naming, reading, word-generation and semantic-decision tasks. The combination of these tasks generated two activation maps related to memory in the mesial temporal lobes, and three language-related maps of activation in a major part of the known language network. The functional maps from the encoding and naming tasks showed typical and symmetrical posterior mesial temporal lobe activation related to memory in all subjects. Only four of nine subjects also showed symmetrical anterior hippocampal activation. Language lateralisation was best with the word generation and reading paradigms and proved possible in all subjects. The reading paradigm enables localisation of language function in the left anterior temporal pole and middle temporal gyrus, areas typically resected during epilepsy surgery. The combined results of this comprehensive f MRI protocol are adequate for a comparative study with the IAT in patients with epilepsy being assessed for surgery. (orig.)

Developing a comprehensive presurgical functional MRI protocol for patients with intractable temporal lobe epilepsy: a pilot study

Energy Technology Data Exchange (ETDEWEB)

Deblaere, K.; Vandemaele, P.; Achten, E. [MRI Department -1 K12, Department of Radiology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Backes, W.H.; Hofman, P.; Wilmink, J. [Department of Neuroradiology, University Hospital Maastricht, Postbus 5800, 6202 AZ Maastricht (Netherlands); Boon, P.A.; Vonck, K. [Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Boon, P. [Department of Medical Psychology, University Hospital Maastricht (Netherlands); Troost, J. [Department of Neurology, University Hospital Maastricht (Netherlands); Vermeulen, J. [S.E.I.N Heemstede, Psychological Laboratory, Achterweg 5, 2103 SW Heemstede (Netherlands); Aldenkamp, A. [Epilepsy Center ' Kempenhaeghe' , Postbus 61, 5900 AB Heeze (Netherlands)

2002-08-01

Our aim was to put together and test a comprehensive functional MRI (fMRI) protocol which could compete with the intracarotid amytal (IAT) or Wada test for the localisation of language and memory function in patients with intractable temporal lobe epilepsy. The protocol was designed to be performed in under 1 h on a standard 1.5 tesla imager. We used five paradigms to test nine healthy right-handed subjects: complex scene-encoding, picture-naming, reading, word-generation and semantic-decision tasks. The combination of these tasks generated two activation maps related to memory in the mesial temporal lobes, and three language-related maps of activation in a major part of the known language network. The functional maps from the encoding and naming tasks showed typical and symmetrical posterior mesial temporal lobe activation related to memory in all subjects. Only four of nine subjects also showed symmetrical anterior hippocampal activation. Language lateralisation was best with the word generation and reading paradigms and proved possible in all subjects. The reading paradigm enables localisation of language function in the left anterior temporal pole and middle temporal gyrus, areas typically resected during epilepsy surgery. The combined results of this comprehensive f MRI protocol are adequate for a comparative study with the IAT in patients with epilepsy being assessed for surgery. (orig.)

[Intracranial remote epidural haematoma as a complication after resection of an occipital lobe metastatic tumour from a testicular embryonal carcinoma – a case report].

Science.gov (United States)

Andrusewicz, Wojciech; Limanówka, Bartosz; Sagan, Leszek; Kojder, Ireneusz

We present the case of a patient who suffered from intracranial epidural haematoma in the left fronto -temporo -parietal region as a complication after left parieto -occipital craniotomy and a resection of a metastatic lesion from a testicular embryonal carcinoma to the left occipital lobe. We also discuss possible causes of this complication.

Turner syndrome: neuroimaging findings: structural and functional.

LENUS (Irish Health Repository)

Mullaney, Ronan

2009-01-01

Neuroimaging studies of Turner syndrome can advance our understanding of the X chromosome in brain development, and the modulatory influence of endocrine factors. There is increasing evidence from neuroimaging studies that TX individuals have significant differences in the anatomy, function, and metabolism of a number of brain regions; including the parietal lobe; cerebellum, amygdala, hippocampus; and basal ganglia; and perhaps differences in "connectivity" between frontal and parieto-occipital regions. Finally, there is preliminary evidence that genomic imprinting, sex hormones and growth hormone have significant modulatory effects on brain maturation in TS.

Alterations of the occipital lobe in schizophrenia.

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Tohid, Hassaan; Faizan, Muhammad; Faizan, Uzma

2015-07-01

The relationship of the occipital lobe of the brain with schizophrenia is not commonly studied; however, this topic is considered an essential subject matter among clinicians and scientists. We conducted this systematic review to elaborate the relationship in depth. We found that most schizophrenic patients show normal occipital anatomy and physiology, a minority showed dwindled values, and some demonstrated augmented function and structure. The findings are laborious to incorporate within single disease models that present the involvement of the occipital lobe in schizophrenia. Schizophrenia progresses clinically in the mid-twenties and thirties and its prognosis is inadequate. Changes in the volume, the gray matter, and the white matter in the occipital lobe are quite evident; however, the mechanism behind this involvement is not yet fully understood. Therefore, we recommend further research to explore the occipital lobe functions and volumes across the different stages of schizophrenia.

Alterations of the occipital lobe in schizophrenia

Science.gov (United States)

Tohid, Hassaan; Faizan, Muhammad; Faizan, Uzma

2015-01-01

The relationship of the occipital lobe of the brain with schizophrenia is not commonly studied; however, this topic is considered an essential subject matter among clinicians and scientists. We conducted this systematic review to elaborate the relationship in depth. We found that most schizophrenic patients show normal occipital anatomy and physiology, a minority showed dwindled values, and some demonstrated augmented function and structure. The findings are laborious to incorporate within single disease models that present the involvement of the occipital lobe in schizophrenia. Schizophrenia progresses clinically in the mid-twenties and thirties and its prognosis is inadequate. Changes in the volume, the gray matter, and the white matter in the occipital lobe are quite evident; however, the mechanism behind this involvement is not yet fully understood. Therefore, we recommend further research to explore the occipital lobe functions and volumes across the different stages of schizophrenia. PMID:26166588

Temporal lobe origin is common in patients who have undergone epilepsy surgery for hypermotor seizures.

Science.gov (United States)

Arain, Amir M; Azar, Nabil J; Lagrange, Andre H; McLean, Michael; Singh, Pradumna; Sonmezturk, Hasan; Konrad, Peter; Neimat, Joseph; Abou-Khalil, Bassel

2016-11-01

Hypermotor seizures are most often reported from the frontal lobe but may also have temporal, parietal, or insular origin. We noted a higher proportion of patients with temporal lobe epilepsy in our surgical cohort who had hypermotor seizures. We evaluated the anatomic localization and surgical outcome in patient with refractory hypermotor seizures who had epilepsy surgery in our center. We identified twenty three patients with refractory hypermotor seizures from our epilepsy surgery database. We analyzed demographics, presurgical evaluation including semiology, MRI, PET scan, interictal/ictal scalp video-EEG, intracranial recording, and surgical outcomes. We evaluated preoperative variables as predictors of outcome. Most patients (65%) had normal brain MRI. Intracranial EEG was required in 20 patients (86.9%). Based on the presurgical evaluation, the resection was anterior temporal in fourteen patients, orbitofrontal in four patients, cingulate in four patients, and temporoparietal in one patient. The median duration of follow-up after surgery was 76.4months. Fourteen patients (60%) had been seizure free at the last follow up while 3 patients had rare disabling seizures. Hypermotor seizures often originated from the temporal lobe in this series of patients who had epilepsy surgery. This large proportion of temporal lobe epilepsy may be the result of a selection bias, due to easier localization and expected better outcome in temporal lobe epilepsy. With extensive presurgical evaluation, including intracranial EEG when needed, seizure freedom can be expected in the majority of patients. Copyright © 2016. Published by Elsevier Inc.

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.

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.

Brain networks governing the golf swing in professional golfers.

Science.gov (United States)

Kim, Jin Hyun; Han, Joung Kyue; Kim, Bung-Nyun; Han, Doug Hyun

2015-01-01

Golf, as with most complex motor skills, requires multiple different brain functions, including attention, motor planning, coordination, calculation of timing, and emotional control. In this study we assessed the correlation between swing components and brain connectivity from the cerebellum to the cerebrum. Ten female golf players and 10 age-matched female controls were recruited. In order to determine swing consistency among participants, the standard deviation (SD) of the mean swing speed time and the SD of the mean swing angle were assessed over 30 swings. Functional brain connectivity was assessed by resting state functional MRI. Pro-golfers showed greater positive left cerebellum connectivity to the occipital lobe, temporal lobe, parietal lobe and both frontal lobes compared to controls. The SD of play scores was positively correlated with the SD of the impact angle. Constant swing speed and back swing angle in professional golfers were associated with functional connectivity (FC) between the cerebellum and parietal and frontal lobes. In addition, the constant impact angle in professional golfers was associated with improved golf scores and additional FC of the thalamus.

Functional magnetic resonance imaging study of neuronal activation during cognitive tasks related to frontal lobe functions in patients with obsessive-compulsive disorder

International Nuclear Information System (INIS)

Koizumi, Hazuki

2010-01-01

Previous neurological studies and brain activation studies using functional magnetic resonance imaging (f-MRI) have suggested frontal lobe dysfunctions in patients with obsessive-compulsive disorder (OCD). However, no f-MRI study has used cognitive tasks reflecting fluency of ideas and memory related to frontal lobe functions. The purposes of this study are to assess the neuropsychological examinations and brain activities of OCD patients using f-MRI, as well as, to investigate the relationship between the severity of obsessive-compulsive symptoms and frontal lobe functions. The subjects were 22 right-handed persons consisting of 11 outpatients who had received a diagnosis of OCD based on diagnostic and statistical manual of mental disorders-fourth edition (DMS-IV) and age- and sex-matched 11 healthy controls. All subjects were examined using Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Wechsler Adult Intelligence Scale-3 rd edition (WAIS-III), Wisconsin Card Sorting Test (WCST), Modified Stroop Test (MST), Verbal Fluency Test (VFT), Idea Fluency Test (IFT), and Rey-Auditory Verbal Learning Test (RAVLT). The brain activities were measured with f-MRI during three cognitive tasks; Task 1: idea generation (IFT), Task 2: word generation (VFT), and Task 3: remembrance of words (RAVLT). The block design was used in the trials, in which rest and activating tasks were alternated for five times in each task. The neuropsychological examinations revealed significant differences in the numbers of categories achieved and total errors in WCST, times of Part I in MST, scores of VFT and IFT, and the results of RAVLT between the OCD patients and healthy controls. Using functional brain imaging with f-MRI, noticeable activations were found in the superior, middle, inferior frontal gyri, and the cingulate gyrus during all tasks in both the OCD and control groups. The OCD patients had significantly higher activation in the cingulate gyrus than normal controls during Task 1 (IFT

Functional and structural brain correlates of theory of mind and empathy deficits in schizophrenia.

Science.gov (United States)

Benedetti, Francesco; Bernasconi, Alessandro; Bosia, Marta; Cavallaro, Roberto; Dallaspezia, Sara; Falini, Andrea; Poletti, Sara; Radaelli, Daniele; Riccaboni, Roberta; Scotti, Giuseppe; Smeraldi, Enrico

2009-10-01

Patients affected by schizophrenia show deficits in social cognition, with abnormal performance on tasks targeting theory of mind (ToM) and empathy (Emp). Brain imaging studies suggested that ToM and Emp depend on the activation of brain networks mainly localized at the superior temporal lobe and temporo-parietal junction. Participants included 24 schizophrenia patients and 20 control subjects. We used brain blood oxygen level dependent fMRI to study the neural responses to tasks targeting ToM and Emp. We then studied voxel-based morphometry of grey matter in areas where diagnosis influenced functional activation to both tasks. Outcomes were analyzed in the context of the general linear model, with global grey matter volume as nuisance covariate for structural MRI. Patients showed worse performance on both tasks. We found significant effects of diagnosis on neural responses to the tasks in a wide cluster in right posterior superior temporal lobe (encompassing BA 22-42), in smaller clusters in left temporo-parietal junction and temporal pole (BA 38 and 39), and in a white matter region adjacent to medial prefrontal cortex (BA 10). A pattern of double dissociation of the effects of diagnosis and task on neural responses emerged. Among these areas, grey matter volume was found to be reduced in right superior temporal lobe regions of patients. Functional and structural abnormalities were observed in areas affected by the schizophrenic process early in the illness course, and known to be crucial for social cognition, suggesting a biological basis for social cognition deficits in schizophrenia.

Bilateral front-parietal polymicrogyria accompanied by cobblestone lissencephaly: 3T MR imaging findings of a case

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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

Evaluation of Cerebral Cortex Function in Clients with Bipolar Mood Disorder I (BMD I Compared With BMD II Using QEEG Analysis

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Ali Khaleghi

2015-10-01

Full Text Available Objective: Early diagnosis of type I and type II bipolar mood disorder is very challenging particularly in adolescence. Hence, we aimed to investigate the cerebral cortex function in these patients, using quantitative electroencephalography analysis to obtain significant differences between them.Methods: Thirty- eight adolescents (18 patients with bipolar disorder I and 20 with BMD II participated in this study. We recorded the electroencephalogram signals based on 10-20 international system by 21 electrodes in eyes open and eyes closed condition resting conditions. Forty seconds segments were selected from each recorded signals with minimal noise and artifacts. Periodogram Welch was used to estimate power spectrum density from each segment. Analysis was performed in five frequency bands (delta, theta, alpha, beta and gamma, and we assessed power, mean, entropy, variance and skewness of the spectrums, as well as mean of the thresholded spectrum and thresholded spectrogram. We only used focal montage for comparison. Eventually, data were analyzed by independent Mann-Whitney test and independent t test.Results: We observed significant differences in some brain regions and in all frequency bands. There were significant differences in prefrontal lobe, central lobe, left parietal lobe, occipital lobe and temporal lobe between BMD I and BMD II (P < 0.05. In patients with BMD I, spectral entropy was compared to patients with BMD II. The most significant difference was observed in the gamma frequency band. Also, the power and entropy of delta frequency band was larger in the left parietal lobe in the BMD I patients compared to BMD II patients (P < 0.05. In the temporal lobe, significant differences were observed in the spectrum distribution of beta and gamma frequency bands (P < 0.05.Conclusion: The QEEG and entropy measure are simple and available tools to help detect cerebral cortex deficits and distinguish BMD I from BMD II.

Functional discrepancy between two liver lobes after hemilobe biliary drainage in patients with jaundice and bile duct cancer: an appraisal using (99m)Tc-GSA SPECT/CT fusion imaging.

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Sumiyoshi, Tatsuaki; Shima, Yasuo; Okabayashi, Takehiro; Noda, Yoshihiro; Hata, Yasuhiro; Murata, Yoriko; Kozuki, Akihito; Tokumaru, Teppei; Nakamura, Toshio; Uka, Kiminori

2014-11-01

To determine the functional discrepancy between the two liver lobes using technetium 99m ((99m)Tc) diethylenetriamine-pentaacetic acid-galactosyl human serum albumin ( GSA diethylenetriamine-pentaacetic acid-galactosyl human serum albumin ) single photon emission computed tomography (SPECT)/computed tomography (CT) fusion imaging following preoperative biliary drainage and portal vein embolization ( PVE portal vein embolization ) in patients with jaundice who have bile duct cancer ( BDC bile duct cancer ). This retrospective study was approved by the institutional review board, with waiver of informed consent. Preoperative (99m)Tc- GSA diethylenetriamine-pentaacetic acid-galactosyl human serum albumin SPECT/CT fusion images from 32 patients with extrahepatic BDC bile duct cancer were retrospectively reviewed. Patients were classified into four groups according to the extent of biliary drainage and presence of a preoperative right PVE portal vein embolization : right lobe drainage group (right drainage), bilateral lobe drainage group (bilateral drainage), left lobe drainage group (left drainage), and left lobe drainage with right PVE portal vein embolization group (left drainage with right PVE portal vein embolization ). Percentage volume and percentage function were measured in each lobe using fusion imaging. The ratio between percentage function and percentage volume (the function-to-volume ratio) was calculated for each lobe, and the results were compared among the four groups. Statistical analysis was performed with Wilcoxon signed-rank tests and Mann-Whitney U tests. The median values for the function-to-volume ratio in the right drainage, bilateral drainage, left drainage, and left drainage with right PVE portal vein embolization group were 1.12, 1.05, 1.02, and 0.81 in the right lobe; and 0.51, 0.88, 0.96, and 1.17 in the left lobe. Significant differences in the function-to-volume ratio were observed among the four groups (right drainage vs bilateral

Altered resting-state functional connectivity in patients with chronic bilateral vestibular failure.

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Göttlich, Martin; Jandl, Nico M; Wojak, Jann F; Sprenger, Andreas; von der Gablentz, Janina; Münte, Thomas F; Krämer, Ulrike M; Helmchen, Christoph

2014-01-01

Patients with bilateral vestibular failure (BVF) suffer from gait unsteadiness, oscillopsia and impaired spatial orientation. Brain imaging studies applying caloric irrigation to patients with BVF have shown altered neural activity of cortical visual-vestibular interaction: decreased bilateral neural activity in the posterior insula and parietal operculum and decreased deactivations in the visual cortex. It is unknown how this affects functional connectivity in the resting brain and how changes in connectivity are related to vestibular impairment. We applied a novel data driven approach based on graph theory to investigate altered whole-brain resting-state functional connectivity in BVF patients (n= 22) compared to age- and gender-matched healthy controls (n= 25) using resting-state fMRI. Changes in functional connectivity were related to subjective (vestibular scores) and objective functional parameters of vestibular impairment, specifically, the adaptive changes during active (self-guided) and passive (investigator driven) head impulse test (HIT) which reflects the integrity of the vestibulo-ocular reflex (VOR). BVF patients showed lower bilateral connectivity in the posterior insula and parietal operculum but higher connectivity in the posterior cerebellum compared to controls. Seed-based analysis revealed stronger connectivity from the right posterior insula to the precuneus, anterior insula, anterior cingulate cortex and the middle frontal gyrus. Excitingly, functional connectivity in the supramarginal gyrus (SMG) of the inferior parietal lobe and posterior cerebellum correlated with the increase of VOR gain during active as compared to passive HIT, i.e., the larger the adaptive VOR changes the larger was the increase in regional functional connectivity. Using whole brain resting-state connectivity analysis in BVF patients we show that enduring bilateral deficient or missing vestibular input leads to changes in resting-state connectivity of the brain. These

Frontal Lobe Contusion in Mice Chronically Impairs Prefrontal-Dependent Behavior.

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Austin Chou

Full Text Available Traumatic brain injury (TBI is a major cause of chronic disability in the world. Moderate to severe TBI often results in damage to the frontal lobe region and leads to cognitive, emotional, and social behavioral sequelae that negatively affect quality of life. More specifically, TBI patients often develop persistent deficits in social behavior, anxiety, and executive functions such as attention, mental flexibility, and task switching. These deficits are intrinsically associated with prefrontal cortex (PFC functionality. Currently, there is a lack of analogous, behaviorally characterized TBI models for investigating frontal lobe injuries despite the prevalence of focal contusions to the frontal lobe in TBI patients. We used the controlled cortical impact (CCI model in mice to generate a frontal lobe contusion and studied behavioral changes associated with PFC function. We found that unilateral frontal lobe contusion in mice produced long-term impairments to social recognition and reversal learning while having only a minor effect on anxiety and completely sparing rule shifting and hippocampal-dependent behavior.

Altered functional connectivity to stressful stimuli in prenatally cocaine-exposed adolescents.

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Zakiniaeiz, Yasmin; Yip, Sarah W; Balodis, Iris M; Lacadie, Cheryl M; Scheinost, Dustin; Constable, R Todd; Mayes, Linda C; Sinha, Rajita; Potenza, Marc N

2017-11-01

Prenatal cocaine exposure (PCE) is linked to addiction and obesity vulnerability. Neural responses to stressful and appetitive cues in adolescents with PCE versus those without have been differentially linked to substance-use initiation. However, no prior studies have assessed cue-reactivity responses among PCE adolescents using a connectivity-based approach. Twenty-two PCE and 22 non-prenatally drug-exposed (NDE) age-, sex-, IQ- and BMI-matched adolescents participated in individualized guided imagery with appetitive (favorite-food), stressful and neutral-relaxing cue scripts during functional magnetic resonance imaging. Subjective favorite-food craving scores were collected before and after script exposure. A data-driven voxel-wise intrinsic connectivity distribution analysis was used to identify between-group differences and examine relationships with craving scores. A group-by-cue interaction effect identified a parietal lobe cluster where PCE versus NDE adolescents showed less connectivity during stressful and more connectivity during neutral-relaxing conditions. Follow-up seed-based connectivity analyses revealed that, among PCE adolescents, the parietal seed was positively connected to inferior parietal and sensory areas and negatively connected to corticolimbic during both stress and neutral-relaxing conditions. For NDE, greater parietal connectivity to parietal, cingulate and sensory areas and lesser parietal connectivity to medial prefrontal areas were found during stress compared to neutral-relaxing cueing. Craving scores inversely correlated with corticolimbic connectivity in PCE, but not NDE adolescents, during the favorite-food condition. Findings from this first data-driven intrinsic connectivity analysis of PCE influences on adolescent brain function indicate differences relating to PCE status and craving. These findings provide insight into the developmental impact of in utero drug exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

The inferior parietal lobule and recognition memory : expectancy violation or successful retrieval?

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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...

[Functional connectivity of temporal parietal junction in online game addicts:a resting-state functional magnetic resonance imaging study].

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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.

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.

Microsurgical techniques in temporal lobe epilepsy.

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Alonso Vanegas, Mario A; Lew, Sean M; Morino, Michiharu; Sarmento, Stenio A

2017-04-01

Temporal lobe resection is the most prevalent epilepsy surgery procedure. However, there is no consensus on the best surgical approach to treat temporal lobe epilepsy. Complication rates are low and efficacy is very high regarding seizures after such procedures. However, there is still ample controversy regarding the best surgical approach to warrant maximum seizure control with minimal functional deficits. We describe the most frequently used microsurgical techniques for removal of both the lateral and mesial temporal lobe structures in the treatment of medically intractable temporal lobe epilepsy (TLE) due to mesial temporal sclerosis (corticoamygdalohippocampectomy and selective amygdalohippocampectomy). The choice of surgical technique appears to remain a surgeon's preference for the near future. Meticulous surgical technique and thorough three-dimensional microsurgical knowledge are essentials for obtaining the best results. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

White matter impairments in autism, evidence from voxel-based morphometry and diffusion tensor imaging.

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Ke, Xiaoyan; Tang, Tianyu; Hong, Shanshan; Hang, Yueyue; Zou, Bing; Li, Huiguo; Zhou, Zhenyu; Ruan, Zongcai; Lu, Zuhong; Tao, Guotai; Liu, Yijun

2009-04-10

This study explored white matter abnormalities in a group of Chinese children with high functioning autism (HFA). Twelve male children with HFA and ten matched typically developing children underwent diffusion tensor imaging (DTI) as well three-dimensional T1-weighted MRI for voxel-based morphometry (VBM). We found a significant decrease of the white matter density in the right frontal lobe, left parietal lobe and right anterior cingulate and a significant increase in the right frontal lobe, left parietal lobe and left cingulate gyrus in the HFA group compared with the control group. The HFA group also had decreased FA in the frontal lobe and left temporal lobe. By combining DT-MRI FA and MRI volumetric analyses based on the VBM model, the results showed consistent white matter abnormalities in a group of Chinese children with HFA.

Mapping brain development during childhood, adolescence and young adulthood

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Guo, Xiaojuan; Jin, Zhen; Chen, Kewei; Peng, Danling; Li, Yao

2009-02-01

Using optimized voxel-based morphometry (VBM), this study systematically investigated the differences and similarities of brain structural changes during the early three developmental periods of human lives: childhood, adolescence and young adulthood. These brain changes were discussed in relationship to the corresponding cognitive function development during these three periods. Magnetic Resonance Imaging (MRI) data from 158 Chinese healthy children, adolescents and young adults, aged 7.26 to 22.80 years old, were included in this study. Using the customized brain template together with the gray matter/white matter/cerebrospinal fluid prior probability maps, we found that there were more age-related positive changes in the frontal lobe, less in hippocampus and amygdala during childhood, but more in bilateral hippocampus and amygdala and left fusiform gyrus during adolescence and young adulthood. There were more age-related negative changes near to central sulcus during childhood, but these changes extended to the frontal and parietal lobes, mainly in the parietal lobe, during adolescence and young adulthood, and more in the prefrontal lobe during young adulthood. So gray matter volume in the parietal lobe significantly decreased from childhood and continued to decrease till young adulthood. These findings may aid in understanding the age-related differences in cognitive function.

Analysis of anatomic variability in children with low mathematical skills

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Han, Zhaoying; Fuchs, Lynn; Davis, Nikki; Cannistraci, Christopher J.; Anderson, Adam W.; Gore, John C.; Dawant, Benoit M.

2008-03-01

Mathematical difficulty affects approximately 5-9% of the population. Studies on individuals with dyscalculia, a neurologically based math disorder, provide important insight into the neural correlates of mathematical ability. For example, cognitive theories, neuropsychological studies, and functional neuroimaging studies in individuals with dyscalculia suggest that the bilateral parietal lobes and intraparietal sulcus are central to mathematical performance. The purpose of the present study was to investigate morphological differences in a group of third grade children with poor math skills. We compare population averages of children with low math skill (MD) to gender and age matched controls with average math ability. Anatomical data were gathered with high resolution MRI and four different population averaging methods were used to study the effect of the normalization technique on the results. Statistical results based on the deformation fields between the two groups show anatomical differences in the bilateral parietal lobes, right frontal lobe, and left occipital/parietal lobe.

Asymmetry of cerebral blood flow in patients with senile dementia of Alzheimer type by SPECT using I-123 IMP

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Arai, Hisayuki; Hanyu, Haruo; Kobayashi, Yasutaka; Hatano, Nobuyoshi; Katsunuma, Hideyo; Suzuki, Takanari; Amino, Saburo [Tokyo Medical Coll. (Japan)

1990-12-01

Regional cerebral blood flow (rCBF) was determined by single photon emission CT (SPECT) with N-isopropyl-p-({sup 123}I)iodoamphetamine in 22 patients with clinically diagnosed senile dementia of Alzheimer type (SDAT) and in 18 age matched controls. We calculated asymmetry indices (AIs) of rCBF for matched right-left regions of interest. rCBF of parietal lobe in SDAT patients was significantly most laterally asymmetrycal, but the least in occipital lobe. Lateral asymmetry of rCBF in SDAT patients correlated with asymmetry of language and visuospatial functions; decreased rCBF in the left parietal lobe was associated with language dysfunction, and that in the right parietal lobe, with viduospatial dysfunction. Furthermore cerebellar AIs correlated negatively with those of the cerebral hemisphere and lower frontal region in SDAT patients. The results demonstrate that rCBF measurement by {sup 123}I-IMP SPECT is useful to detect lateral asymmetry in reduction of rCBF in SDAT. (author).

Asymmetry of cerebral blood flow in patients with senile dementia of Alzheimer type by SPECT using I-123 IMP

International Nuclear Information System (INIS)

Arai, Hisayuki; Hanyu, Haruo; Kobayashi, Yasutaka; Hatano, Nobuyoshi; Katsunuma, Hideyo; Suzuki, Takanari; Amino, Saburo

1990-01-01

Regional cerebral blood flow (rCBF) was determined by single photon emission CT (SPECT) with N-isopropyl-p-[ 123 I]iodoamphetamine in 22 patients with clinically diagnosed senile dementia of Alzheimer type (SDAT) and in 18 age matched controls. We calculated asymmetry indices (AIs) of rCBF for matched right-left regions of interest. rCBF of parietal lobe in SDAT patients was significantly most laterally asymmetrycal, but the least in occipital lobe. Lateral asymmetry of rCBF in SDAT patients correlated with asymmetry of language and visuospatial functions; decreased rCBF in the left parietal lobe was associated with language dysfunction, and that in the right parietal lobe, with viduospatial dysfunction. Furthermore cerebellar AIs correlated negatively with those of the cerebral hemisphere and lower frontal region in SDAT patients. The results demonstrate that rCBF measurement by 123 I-IMP SPECT is useful to detect lateral asymmetry in reduction of rCBF in SDAT. (author)

Methodology for functional MRI of simulated driving.

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Kan, Karen; Schweizer, Tom A; Tam, Fred; Graham, Simon J

2013-01-01

The developed world faces major socioeconomic and medical challenges associated with motor vehicle accidents caused by risky driving. Functional magnetic resonance imaging (fMRI) of individuals using virtual reality driving simulators may provide an important research tool to assess driving safety, based on brain activity and behavior. A fMRI-compatible driving simulator was developed and evaluated in the context of straight driving, turning, and stopping in 16 young healthy adults. Robust maps of brain activity were obtained, including activation of the primary motor cortex, cerebellum, visual cortex, and parietal lobe, with limited head motion (driving is a feasible undertaking.

Encefalomenigocele atrésico parietal Parietal atresic encephalomeningocele

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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.

A clinical case of the schizophrenia-like organic personality syndrome after neck hanging with special reference to the brain positron CT showing the lowered functioning in frontal lobe

International Nuclear Information System (INIS)

Koizumi, Junzo; Takeuchi, Tatsuo; Ono, Yukio; Kozuki, Hideki; Iio, Masaaki.

1985-01-01

A 21-year-old woman developed schizophrenia-like organic personality syndrome subsequent to neck hanging. Brain positron CT with 11 CO, 15 O 2 , and C 15 O 2 showed decreased blood flow in the frontal lobe, decreased glucose metabolism in the frontal and lateral lobes, decreased cerebral metabolic rate of oxygen, and decreased cerebral blood flow, suggesting lowered functioning in the frontal lobe. Since these CT findings were very similar to those in patients with chronic sphizophrenia, clinical symptoms of sphizophrenia seems to be related to lowered functioning in the frontal lobe. (Namekawa, K.)

18F-FDG uptake changes in the brain functional loop in patients with refractory obsessive compulsive disorder

International Nuclear Information System (INIS)

Qiu Chun; Guan Yihui; Chen Limin; Sun Bomin; Li Dianyou; Huang Zhemin; Zhao Jun; Zuo Chuantao

2011-01-01

Objective: To investigate the glucose metabolic pattern of brain functional loop in patients with refractory obsessive compulsive disorder (OCD) using 18 F-FDG PET. Methods: Eight patients with refractory OCD and 8 age- and gender-matched healthy volunteers underwent 18 F-FDG PET brain imaging. SPM software was used for image post-processing and quantitative analysis. Correlation analysis between 18 F-FDG uptake and Yale-Brown obsessive compulsive scale(Y-BOCS) score was performed. Results: Compared with the controls, the glucose metabolism of bilateral frontal cortices (including the rectal gyrus,orbital gyrus and cingulate gyrus), left thalamus,right temporal lobe and bilateral cerebellum in refractory OCD patients increased significantly (Z max =3.45-5.80, all P<0.001). Bilateral motor cortices and bilateral parietal lobes (BA7), however, showed decreased glucose metabolism (Z max =3.44-4.46, all P<0.001). Y-BOCS score was positively correlated with the glucose metabolism of the bilateral anterior cingulate cortex (Z max =3.77, 3.48 and 2.97, all P<0.01). Conclusions: There is a characteristic metabolic pattern of increased glucose utilization in the fronto-striato-thalamic loop and decreased glucose utilization in bilateral motor cortices and parietal lobes in patients with OCD. The glucose metabolism in the anterior cingulate cortex might serve as a quantitative parameter for the assessment of the severity of OCD. (authors)

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

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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

Preservation of episodic memory in semantic dementia: The importance of regions beyond the medial temporal lobes.

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Irish, Muireann; Bunk, Steffie; Tu, Sicong; Kamminga, Jody; Hodges, John R; Hornberger, Michael; Piguet, Olivier

2016-01-29

Episodic memory impairment represents one of the hallmark clinical features of patients with Alzheimer's disease (AD) attributable to the degeneration of medial temporal and parietal regions of the brain. In contrast, a somewhat paradoxical profile of relatively intact episodic memory, particularly for non-verbal material, is observed in semantic dementia (SD), despite marked atrophy of the hippocampus. This retrospective study investigated the neural substrates of episodic memory retrieval in 20 patients with a diagnosis of SD and 21 disease-matched cases of AD and compared their performance to that of 35 age- and education-matched healthy older Controls. Participants completed the Rey Complex Figure and the memory subscale of the Addenbrooke's Cognitive Examination-Revised as indices of visual and verbal episodic recall, respectively. Relative to Controls, AD patients showed compromised memory performance on both visual and verbal memory tasks. In contrast, memory deficits in SD were modality-specific occurring exclusively on the verbal task. Controlling for semantic processing ameliorated these deficits in SD, while memory impairments persisted in AD. Voxel-based morphometry analyses revealed significant overlap in the neural correlates of verbal episodic memory in AD and SD with predominantly anteromedial regions, including the bilateral hippocampus, strongly implicated. Controlling for semantic processing negated this effect in SD, however, a distributed network of frontal, medial temporal, and parietal regions was implicated in AD. Our study corroborates the view that episodic memory deficits in SD arise very largely as a consequence of the conceptual loading of traditional tasks. We propose that the functional integrity of frontal and parietal regions enables new learning to occur in SD in the face of significant hippocampal and anteromedial temporal lobe pathology, underscoring the inherent complexity of the episodic memory circuitry. Copyright © 2015

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.

Vulnerability of the frontal and parietal regions in hypertensive patients during working memory task.

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Li, Xin; Wang, Wenxiao; Wang, Ailin; Li, Peng; Zhang, Junying; Tao, Wuhai; Zhang, Zhanjun

2017-05-01

Hypertension is related with cognitive decline in the elderly. The frontal-parietal executive system plays an important role in cognitive aging and is also vulnerable to damage in elderly patients with hypertension. Examination of the brain's functional characteristics in frontal-parietal regions of hypertension is likely to be important for understanding the neural mechanisms of hypertension's effect on cognitive aging. We address this issue by comparing hypertension and control-performers in a functional MRI study. Twenty-eight hypertensive patients and 32 elderly controls were tested with n-back task with two load levels. The hypertensive patients exhibited worse executive and memory abilities than control subjects. The patterns of brain activation changed under different working memory loads in the hypertensive patients, who exhibited reduced activation only in the precentral gyrus under low loads and reduced activation in the middle frontal gyrus, left medial superior frontal gyrus and right precuneus under high loads. Thus, more regions of diminished activation were observed in the frontal and parietal regions with increasing task difficulty. More importantly, we found that lower activation in changed frontal and parietal regions was associated with worse cognitive function in high loads. The results demonstrate the relationship between cognitive function and frontoparietal functional activation in hypertension and their relevance to cognitive aging risk. Our findings provide a better understanding of the mechanism of cognitive decline in hypertension and highlight the importance of brain protection in hypertension.

Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy.

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Lambon Ralph, Matthew A; Ehsan, Sheeba; Baker, Gus A; Rogers, Timothy T

2012-01-01

Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients' accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency

Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia.

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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.

Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia

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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

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

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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.

Influence of electroencephalograph bionic electrical stimulation on neuronal activities in patients with Alzheimer's disease: A functional magnetic resonance imaging study

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Liling Jiang

2018-03-01

Full Text Available Purpose: To investigate the influence of electroencephalograph bionic electrical stimulation on neuronal activity in patients with Alzheimer's disease (AD using resting-state blood oxygen level dependent functional MRI (BOLD-fMRI and amplitude of low-frequency fluctuation (ALFF and fraction ALFF (fALFF analysis. Methods: 42 AD patients were divided into two groups in accordance with the randomized double blind principle, every group was 21. Treatment group received electroencephalograph bionic electrical stimulation. Both groups received resting-state BOLD-fMRI scanning before and after treatment and comparing differences in ALFF and fALFF in each group by statistical methods. Correlation analysis was performed between ALFF or fALFF images and neuropsychological tests scale after treatment. Results: Post-therapy brain regions with higher ALFF included left cerebellum posterior lobe, right cerebellum posterior lobe, left hippocampus/parahippocampus, left posterior cingulated cortex, left dorsolateral prefrontal cortex, right inferior parietal lobule in treatment group. Higher fALFF was observed in the right inferior parietal lobule. In the placebo group lower ALFF was observed in bilateral cerebellum posterior lobe and left posterior cingulated cortex. Alzheimer's Disease Assessment Scale-Cognitive section was closely correlated with ALFF in left cerebellum posterior lobe and right cerebellum posterior lobe. Conclusion: These results indicated improved neuronal activity in some brain areas could be achieved in AD after treatment of electroencephalograph bionic electrical stimulation. The change of BOLD-fMRI signal might provide a potential imaging strategy for studying neural mechanisms of electroencephalograph bionic electrical stimulation for AD. Keywords: Electroencephalograph bionic electrical stimulation, Alzheimer's disease, Low-frequency fluctuation, Fraction low-frequency fluctuation

Functional network-based statistics in depression: Theory of mind subnetwork and importance of parietal region.

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Lai, Chien-Han; Wu, Yu-Te; Hou, Yuh-Ming

2017-08-01

The functional network analysis of whole brain is an emerging field for research in depression. We initiated this study to investigate which subnetwork is significantly altered within the functional connectome in major depressive disorder (MDD). The study enrolled 52 first-episode medication-naïve patients with MDD and 40 controls for functional network analysis. All participants received the resting-state functional imaging using a 3-Tesla magnetic resonance scanner. After preprocessing, we calculated the connectivity matrix of functional connectivity in whole brain for each subject. The network-based statistics of connectome was used to perform group comparisons between patients and controls. The correlations between functional connectivity and clinical parameters were also performed. MDD patients had significant alterations in the network involving "theory of mind" regions, such as the left precentral gyrus, left angular gyrus, bilateral rolandic operculums and left inferior frontal gyrus. The center node of significant network was the left angular gyrus. No significant correlations of functional connectivity within the subnetwork and clinical parameters were noted. Functional connectivity of "theory of mind" subnetwork may be the core issue for pathophysiology in MDD. In addition, the center role of parietal region should be emphasized in future study. Copyright © 2017. Published by Elsevier B.V.

White matter integrity in dyskinetic cerebral palsy: Relationship with intelligence quotient and executive function

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Olga Laporta-Hoyos

2017-01-01

Conclusion: The widespread loss in the integrity of WM tissue is mainly located in the parietal lobe and related to IQ in dyskinetic CP. Unexpectedly, executive functions are only related with WM microstructure in regions containing fronto-cortical and posterior cortico-subcortical pathways, and not being specifically related to the state of fronto-striatal pathways which might be due to brain reorganization. Further studies of this nature may improve our understanding of the neurobiological bases of cognitive impairments after early brain insult.

Flash visual evoked potentials are not specific enough to identify parieto-occipital lobe involvement in term neonates after significant hypoglycaemia.

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Hu, Liyuan; Gu, Qiufang; Zhu, Zhen; Yang, Chenhao; Chen, Chao; Cao, Yun; Zhou, Wenhao

2014-08-01

Hypoglycaemia is a significant problem in high-risk neonates and predominant parieto-occipital lobe involvement has been observed after severe hypoglycaemic insult. We explored the use of flash visual evoked potentials (FVEP) in detecting parieto-occipital lobe involvement after significant hypoglycaemia. Full-term neonates (n = 15) who underwent FVEP from January 2008 to May 2013 were compared with infants (n = 11) without hypoglycaemia or parietal-occipital lobe injury. Significant hypoglycaemia was defined as being symptomatic or needing steroids, glucagon or a glucose infusion rate of ≥12 mg/kg/min. The hypoglycaemia group exhibited delayed latency of the first positive waveform on FVEP. The initial detected time for hypoglycaemia was later in the eight subjects with seizures (median 51-h-old) than those without (median 22-h-old) (P = 0.003). Magnetic resonance imaging showed that 80% of the hypoglycaemia group exhibited occipital-lobe injuries, and they were more likely to exhibit abnormal FVEP morphology (P = 0.007) than the controls. FVEP exhibited 100% sensitivity, but only 25% specificity, for detecting injuries to the parieto-occipital lobes. Flash visual evoked potential (FVEP) was sensitive, but not sufficiently specific, in identifying parieto-occipital lobe injuries among term neonates exposed to significant hypoglycaemia. Larger studies exploring the potential role of FVEP in neonatal hypoglycaemia are required. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Temporal and extra-temporal hypoperfusion in medial temporal lobe epilepsy evaluated by arterial-spin-labeling based MRI

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Shen Lianfang; Zhang Zhiqiang; Lu Guangming; Yuan Cuiping; Wang Zhengge; Wang Haoxue; Huang Wei; Wei Fangyuan; Chen Guanghui; Tan Qifu

2012-01-01

Objective: To evaluate the feasibility of the lateralization of unilateral medial temporal lobe epilepsy (mTLE) by using arterial-spin-labeling (ASL) based perfusion MR imaging and investigate the changes of perfusion in the regions related to mTLE network and the relationship between the perfusion and the clinical status. Methods: Twenty-five patients with left-sided and 23 with right-sided mTLE were enrolled, and 30 healthy volunteers were recruited. The cerebral blood flow (CBF) of related region was measured based on pulsed-ASL sequence on Siemens 3 T scanner. The CBF of the mTLE group were compared with that in the controls by using ANOVA analysis. The asymmetric indices of CBF in the medial temporal lobe were calculated as the lesion side compared with the normal side in matched region in mTLE group. Results: Compared with the volunteers, the patients with mTLE showed the decrease of CBF in the bilateral medial and lateral temporal, the frontal and parietal regions relating to the default-mode network and more serious in lesion side. The CBF values of the medial temporal lobe were negatively correlated with the epilepsy duration (r=-0.51, P<0.01). The asymmetric index of CBF as-0.01 has a 76.0% (19/25) sensitivity and a 78.3% (18/23) specificity to distinguish the lesion side. Conclusions: The decrease of CBF in the temporal and extra-temporal region by ASL-based MRI suggests the functional abnormalities in the network involved by mTLE. The ASL technique is a useful tool for lateralizing the unilateral mTLE. (authors)

[Different patterns of brain activation between patients of Alzheimer's disease with and without depression: a functional MRI study during emotion Stroop task].

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Wang, Hai-tao; Jia, Jian-ping

2007-04-03

To examine whether emotional factor influences the depression onset in Alzheimer's disease (AD). Twenty mild AD patients conforming to the of DSM-IV criteria with a clinical dementia rating score of 1.0 were divided into 2 groups: 11 patients without depression (AD group), and 9 patients with depression confirming to the National Institute of Mental Health-dAD criteria with a Cornell scale for depression in dementia score>12 (dAD group), without significant differences in age, gender, educational level, onset duration, and MMSE scores between these 2 groups. Ten age-and gender ratio-matched healthy elderly subjects were used as controls. Emotion Stroop task was performed to these 3 groups: emotion Stroop task images were presented with colored positive or negative emotion words (such as HAPPY or SUICIDE, etc.) at the left part of the image to induce emotional responses and with pure color at the right part of the image. The subjects were asked to press the right button when the ink color of the emotion word was congruent with the color at the right part, and press the left button when the ink color of the word was not congruent with the color at the right part. Neutral words were used in the test of general word task. The reaction time, false ratio, and missing ratio were recorded. Functional MRI (fMRI) was conducted. The behavioral data were analyzed with SPSS 11.0 software and the fMRI data were analyzed with SPM2 software. The emotion Stroop task showed that the reaction time of the normal control group was 848 ms+/-320 ms, significantly shorter than those of the dAD and AD groups (1528 ms+/-302 ms and 1173 ms+/-237 ms respectively, both Pdifference between the latter 2 groups (P=0.22). The missing ratio of the normal control group was 0, significantly lower than those of the AD and dAD groups (3.1% and 2.5% respectively, both Pdifference between the latter 2 groups (P=0.29). The fMRI results showed that the bilateral amygdala, left parietal lobe, and left

Older people experiencing homelessness show marked impairment on tests of frontal lobe function.

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Rogoz, Astrid; Burke, David

2016-03-01

Reported rates of mild and moderate cognitive impairment in older people experiencing homelessness range from 5-80%. The objective of this study was to determine the prevalence and characteristics of cognitive impairment in older people experiencing homelessness in the inner city of Sydney, Australia. Men and women experiencing homelessness aged 45 years and over in the inner city were screened for cognitive impairment. Participants who scored 26 or below on the mini-mental state examination and/or were impaired on any one of the clock-drawing test, the verbal fluency test and the trail-making test, part B were then assessed with a semi-structured interview, including the 21-item Depression Anxiety Stress Scale and the 12-item General Health Questionnaire. Screening of 144 men and 27 women aged between 45 years and 93 years identified cognitive impairment in 78%. Subsequently, high rates of mental and physical illness were identified, and 75% of subjects who were cognitively impaired performed poorly on frontal lobe tests. The trail-making test, part B was the most sensitive measure of frontal function. This study demonstrated that a large majority of older people experiencing homelessness, in the inner city of a high-income country, showed impairment on tests of frontal lobe function, a finding that could have significant implications for any medical or psychosocial intervention. Copyright © 2015 John Wiley & Sons, Ltd.

Functional brain networks involved in decision-making under certain and uncertain conditions

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Farrar, Danielle C.; Moss, Mark B.; Killiany, Ronald J. [Boston University School of Medicine, Department of Anatomy and Neurobiology, Boston, MA (United States); Mian, Asim Z. [Boston University School of Medicine, Department of Radiology, Boston, MA (United States); Budson, Andrew E. [VA Boston Healthcare System, Boston, MA (United States)

2018-01-15

The aim of this study was to describe imaging markers of decision-making under uncertain conditions in normal individuals, in order to provide baseline activity to compare to impaired decision-making in pathological states. In this cross-sectional study, 19 healthy subjects ages 18-35 completed a novel decision-making card-matching task using a Phillips T3 Scanner and a 32-channel head coil. Functional data were collected in six functional runs. In one condition of the task, the participant was certain of the rule to apply to match the cards; in the other condition, the participant was uncertain. We performed cluster-based comparison of the two conditions using FSL fMRI Expert Analysis Tool and network-based analysis using MATLAB. The uncertain > certain comparison yielded three clusters - a midline cluster that extended through the midbrain, the thalamus, bilateral prefrontal cortex, the striatum, and bilateral parietal/occipital clusters. The certain > uncertain comparison yielded bilateral clusters in the insula, parietal and temporal lobe, as well as a medial frontal cluster. A larger, more connected functional network was found in the uncertain condition. The involvement of the insula, parietal cortex, temporal cortex, ventromedial prefrontal cortex, and orbitofrontal cortex of the certain condition reinforces the notion that certainty is inherently rewarding. For the uncertain condition, the involvement of the prefrontal cortex, parietal cortex, striatum, thalamus, amygdala, and hippocampal involvement was expected, as these are areas involved in resolving uncertainty and rule updating. The involvement of occipital cortical involvement and midbrain involvement may be attributed to increased visual attention and increased motor control. (orig.)

Functional brain networks involved in decision-making under certain and uncertain conditions

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Farrar, Danielle C.; Moss, Mark B.; Killiany, Ronald J.; Mian, Asim Z.; Budson, Andrew E.

2018-01-01

The aim of this study was to describe imaging markers of decision-making under uncertain conditions in normal individuals, in order to provide baseline activity to compare to impaired decision-making in pathological states. In this cross-sectional study, 19 healthy subjects ages 18-35 completed a novel decision-making card-matching task using a Phillips T3 Scanner and a 32-channel head coil. Functional data were collected in six functional runs. In one condition of the task, the participant was certain of the rule to apply to match the cards; in the other condition, the participant was uncertain. We performed cluster-based comparison of the two conditions using FSL fMRI Expert Analysis Tool and network-based analysis using MATLAB. The uncertain > certain comparison yielded three clusters - a midline cluster that extended through the midbrain, the thalamus, bilateral prefrontal cortex, the striatum, and bilateral parietal/occipital clusters. The certain > uncertain comparison yielded bilateral clusters in the insula, parietal and temporal lobe, as well as a medial frontal cluster. A larger, more connected functional network was found in the uncertain condition. The involvement of the insula, parietal cortex, temporal cortex, ventromedial prefrontal cortex, and orbitofrontal cortex of the certain condition reinforces the notion that certainty is inherently rewarding. For the uncertain condition, the involvement of the prefrontal cortex, parietal cortex, striatum, thalamus, amygdala, and hippocampal involvement was expected, as these are areas involved in resolving uncertainty and rule updating. The involvement of occipital cortical involvement and midbrain involvement may be attributed to increased visual attention and increased motor control. (orig.)

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

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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.

Prospective relations between resting-state connectivity of parietal subdivisions and arithmetic competence.

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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.

Value of analyzing deep gray matter and occipital lobe perfusion to differentiate dementia with Lewy bodies from Alzheimer's disease.

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Shimizu, Soichiro; Hanyu, Haruo; Hirao, Kentaro; Sato, Tomohiko; Iwamoto, Toshihiko; Koizumi, Kiyoshi

2008-12-01

Dementia with Lewy bodies (DLB) is generally characterized by a decrease in regional cerebral blood flow (rCBF) in the occipital lobe. However, not all patients with DLB have this feature. We explored characteristics of rCBF pattern changes to improve the identification of DLB, in addition to occipital hypoperfusion. The study population comprised 30 patients with probable DLB and 49 patients with probable Alzheimer's disease (AD) who underwent single-photon emission computed tomography. The data were analyzed using Neurological Statistical Image Analysis Software (NEUROSTAT). We established a template of the region of interest (ROI) presenting the parietal lobe, posterior cingulate, striatum, thalamus, and occipital lobe on the standard brain atlas. We then compared the mean Z scores in each ROI between DLB and AD. Moreover, we investigated the value of analyzing relative rCBF changes in both the deep gray matter and occipital lobe in differentiating DLB from AD. The DLB group showed a significant relative rCBF increase in the bilateral striatum and thalamus, and a significant relative rCBF decrease in the bilateral occipital lobe when compared with the AD group. Receiver-operating characteristic analysis revealed that determining the hyperperfusion in the thalamus together with the hypoperfusion in the occipital lobe enabled a more accurate differentiation between DLB and AD than studying individual areas. Studying the relative increase of rCBF in the deep gray matter, and the relative decrease of that in the occipital lobe achieved a high differentiation between DLB and AD. This suggests that determining both an increase and a decrease in rCBF pattern may be important in differentiating between the two diseases.

Value of analyzing deep gray matter and occipital lobe perfusion to differentiate dementia with Lewy bodies from Alzheimer's disease

International Nuclear Information System (INIS)

Shimizu, Soichiro; Hanyu, Haruo; Hirao, Kentaro; Sato, Tomohiko; Iwamoto, Toshihiko; Koizumi, Kiyoshi

2008-01-01

Dementia with Lewy bodies (DLB) is generally characterized by a decrease in regional cerebral blood flow (rCBF) in the occipital lobe. However, not all patients with DLB have this feature. We explored characteristics of rCBF pattern changes to improve the identification of DLB, in addition to occipital hypoperfusion. The study population comprised 30 patients with probable DLB and 49 patients with probable Alzheimer's disease (AD) who underwent single-photon emission computed tomography. The data were analyzed using Neurological Statistical Image Analysis Soft-ware (NEUROSTAT). We established a template of the region of interest (ROI) presenting the parietal lobe, posterior cingulate, striatum, thalamus, and occipital lobe on the standard brain atlas. We then compared the mean Z scores in each ROI between DLB and AD. Moreover, we investigated the value of analyzing relative rCBF changes in both the deep gray matter and occipital lobe in differentiating DLB from AD. The DLB group showed a significant relative rCBF increase in the bilateral striatum and thalamus, and a significant relative rCBF decrease in the bilateral occipital lobe when compared with the AD group. Receiver-operating characteristic analysis revealed that determining the hyperperfusion in the thalamus together with the hypoperfusion in the occipital lobe enabled a more accurate differentiation between DLB and AD than studying individual areas. Studying the relative increase of rCBF in the deep gray matter, and the relative decrease of that in the occipital lobe achieved a high differentiation between DLB and AD. This suggests that determining both an increase and a decrease in rCBF pattern may be important in differentiating between the two diseases. (author)

Cerebral asymmetries: complementary and independent processes.

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Gjurgjica Badzakova-Trajkov

Full Text Available Most people are right-handed and left-cerebrally dominant for speech, leading historically to the general notion of left-hemispheric dominance, and more recently to genetic models proposing a single lateralizing gene. This hypothetical gene can account for higher incidence of right-handers in those with left cerebral dominance for speech. It remains unclear how this dominance relates to the right-cerebral dominance for some nonverbal functions such as spatial or emotional processing. Here we use functional magnetic resonance imaging with a sample of 155 subjects to measure asymmetrical activation induced by speech production in the frontal lobes, by face processing in the temporal lobes, and by spatial processing in the parietal lobes. Left-frontal, right-temporal, and right-parietal dominance were all intercorrelated, suggesting that right-cerebral biases may be at least in part complementary to the left-hemispheric dominance for language. However, handedness and parietal asymmetry for spatial processing were uncorrelated, implying independent lateralizing processes, one producing a leftward bias most closely associated with handedness, and the other a rightward bias most closely associated with spatial attention.

Convergent functional architecture of the superior parietal lobule unraveled with multimodal neuroimaging approaches.

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Wang, Jiaojian; Yang, Yong; Fan, Lingzhong; Xu, Jinping; Li, Changhai; Liu, Yong; Fox, Peter T; Eickhoff, Simon B; Yu, Chunshui; Jiang, Tianzi

2015-01-01

The superior parietal lobule (SPL) plays a pivotal role in many cognitive, perceptive, and motor-related processes. This implies that a mosaic of distinct functional and structural subregions may exist in this area. Recent studies have demonstrated that the ongoing spontaneous fluctuations in the brain at rest are highly structured and, like coactivation patterns, reflect the integration of cortical locations into long-distance networks. This suggests that the internal differentiation of a complex brain region may be revealed by interaction patterns that are reflected in different neuroimaging modalities. On the basis of this perspective, we aimed to identify a convergent functional organization of the SPL using multimodal neuroimaging approaches. The SPL was first parcellated based on its structural connections as well as on its resting-state connectivity and coactivation patterns. Then, post hoc functional characterizations and connectivity analyses were performed for each subregion. The three types of connectivity-based parcellations consistently identified five subregions in the SPL of each hemisphere. The two anterior subregions were found to be primarily involved in action processes and in visually guided visuomotor functions, whereas the three posterior subregions were primarily associated with visual perception, spatial cognition, reasoning, working memory, and attention. This parcellation scheme for the SPL was further supported by revealing distinct connectivity patterns for each subregion in all the used modalities. These results thus indicate a convergent functional architecture of the SPL that can be revealed based on different types of connectivity and is reflected by different functions and interactions. © 2014 Wiley Periodicals, Inc.

Inferior parietal and right frontal contributions to trial-by-trial adaptations of attention to memory.

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Kizilirmak, Jasmin M; Rösler, Frank; Bien, Siegfried; Khader, Patrick H

2015-07-21

The attention to memory theory (AtoM) proposes that the same brain regions might be involved in selective processing of perceived stimuli (selective attention) and memory representations (selective retrieval). Although this idea is compelling, given consistently found neural overlap between perceiving and remembering stimuli, recent comparisons brought evidence for overlap as well as considerable differences. Here, we present a paradigm that enables the investigation of the AtoM hypothesis from a novel perspective to gain further insight into the neural resources involved in AtoM. Selective attention in perception is often investigated as a control process that shows lingering effects on immediately following trials. Here, we employed a paradigm capable of modulating selective retrieval in a similarly dynamic manner as in such selective-attention paradigms by inducing trial-to-trial shifts between relevant and irrelevant memory representations as well as changes of the width of the internal focus on memory. We found evidence for an involvement of bilateral inferior parietal lobe and right inferior frontal gyrus in reorienting the attentional focus on previously accessed memory representations. Moreover, we could dissociate the right inferior from the parietal activation in separate contrasts, suggesting that the right inferior frontal gyrus plays a role in facilitating attentional reorienting to memory representations when competing representations have been activated in the preceding trial, potentially by resolving this competition. Our results support the AtoM theory, i.e. that ventral frontal and parietal regions are involved in automatic attentional reorienting in memory, and highlight the importance of further investigations of the overlap and differences between regions involved in internal (memory) and external (perceptual) attentional selection. Copyright © 2015 Elsevier B.V. All rights reserved.

Learning related modulation of functional retrieval networks in man.

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Petersson, K M; Sandblom, J; Gisselgård, J; Ingvar, M

2001-07-01

The medial temporal lobe has been implicated in studies of episodic memory tasks involving spatio-temporal context and object-location conjunctions. We have previously demonstrated that an increased level of practice in a free-recall task parallels a decrease in the functional activity of several brain regions, including the medial temporal lobe, the prefrontal, the anterior cingulate, the anterior insular, and the posterior parietal cortices, that in concert demonstrate a move from elaborate controlled processing towards a higher degree of automaticity. Here we report data from two experiments that extend these initial observations. We used a similar experimental approach but probed for effects of retrieval paradigms and stimulus material. In the first experiment we investigated practice related changes during recognition of object-location conjunctions and in the second during free-recall of pseudo-words. Learning in a neural network is a dynamic consequence of information processing and network plasticity. The present and previous PET results indicate that practice can induce a learning related functional restructuring of information processing. Different adaptive processes likely subserve the functional re-organisation observed. These may in part be related to different demands for attentional and working memory processing. It appears that the role(s) of the prefrontal cortex and the medial temporal lobe in memory retrieval are complex, perhaps reflecting several different interacting processes or cognitive components. We suggest that an integrative interactive perspective on the role of the prefrontal and medial temporal lobe is necessary for an understanding of the processing significance of these regions in learning and memory. It appears necessary to develop elaborated and explicit computational models for prefrontal and medial temporal functions in order to derive detailed empirical predictions, and in combination with an efficient use and development of

Altered organization of face processing networks in temporal lobe epilepsy

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Riley, Jeffrey D.; Fling, Brett W.; Cramer, Steven C.; Lin, Jack J.

2015-01-01

SUMMARY Objective Deficits in social cognition are common and significant in people with temporal lobe epilepsy (TLE), but the functional and structural underpinnings remain unclear. The present study investigated how the side of seizure focus impacts face processing networks in temporal lobe epilepsy. Methods We used functional magnetic resonance imaging (fMRI) of a face processing paradigm to identify face responsive regions in 24 individuals with unilateral temporal lobe epilepsy (Left = 15; Right = 9) and 19 healthy controls. fMRI signals of face responsive regions ispilateral and contralateral to the side of seizure onset were delineated in TLE and compared to the healthy controls with right and left side combined. Diffusion tensor images were acquired to investigate structural connectivity between face regions that differed in fMRI signals between the two groups. Results In temporal lobe epilepsy, activation of the cortical face processing networks varied according to side of seizure onset. In temporal lobe epilepsy, the laterality of amygdala activation was shifted to the side contralateral to the seizure focus while controls showed no significant asymmetry. Furthermore, compared to controls, patients with TLE showed decreased activation of the occipital face responsive region in the ipsilateral side and an increased activity of the anterior temporal lobe in the contralateral side to the seizure focus. Probabilistic tractography revealed that the occipital face area and anterior temporal lobe are connected via the inferior longitudinal fasciculus, which in individuals with temporal lobe epilepsy showed reduced integrity. Significance Taken together, these findings suggest that brain function and white matter integrity of networks subserving face processing are impaired on the side of seizure onset, accompanied by altered responses on the side contralateral to the seizure. PMID:25823855

Functional neuroimaging studies of episodic memory. Functional dissociation in the medial temporal lobe structures

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Tsukiura, Takashi

2008-01-01

Previous functional neuroimaging studies have demonstrated the critical role of the medial temporal lobe (MTL) regions in the encoding and retrieval of episodic memory. It has also been shown that an emotional factor in human memory enhances episodic encoding and retrieval. However, there is little evidence regarding the specific contribution of each MTL region to the relational, contextual, and emotional processes of episodic memory. The goal of this review article is to identify differential activation patterns of the processes between MTL regions. Results from functional neuroimaging studies of episodic memory show that the hippocampus is involved in encoding the relation between memory items, whereas the entorhinal and perirhinal cortices (anterior parahippocampal gyrus) contribute to the encoding of a single item. Additionally, the parahippocampal cortex (posterior parahippocampal gyrus) is selectively activated during the processing of contextual information of episodic memory. A similar pattern of functional dissociation is found in episodic memory retrieval. Functional neuroimaging has also shown that emotional information of episodic memory enhances amygdala-MTL correlations and that this enhancement is observed during both the encoding and retrieval of emotional memories. These findings from pervious neuroimaging studies suggest that different MTL regions could organize memory for personally experienced episodes via the 'relation' and 'context' factors of episodic memory, and that the emotional factor of episodes could modulate the functional organization in the MTL regions. (author)

Emphysema lung lobe volume reduction: effects on the ipsilateral and contralateral lobes

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Brown, Matthew S.; Kim, Hyun J.; Abtin, Fereidoun G.; Galperin-Aizenberg, Maya; Pais, Richard; Da Costa, Irene G.; Ordookhani, Arash; Chong, Daniel; Ni, Chiayi; McNitt-Gray, Michael F.; Goldin, Jonathan G. [David Geffen School of Medicine at UCLA, Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, Los Angeles, CA (United States); Strange, Charlie [Medical University of South Carolina, Department of Pulmonary and Critical Care Medicine, Columbia, SC (United States); Tashkin, Donald P. [David Geffen School of Medicine at UCLA, Division of Pulmonary and Critical Care Medicine, Los Angeles, CA (United States)

2012-07-15

To investigate volumetric and density changes in the ipsilateral and contralateral lobes following volume reduction of an emphysematous target lobe. The study included 289 subjects with heterogeneous emphysema, who underwent bronchoscopic volume reduction of the most diseased lobe with endobronchial valves and 132 untreated controls. Lobar volume and low-attenuation relative area (RA) changes post-procedure were measured from computed tomography images. Regression analysis (Spearman's rho) was performed to test the association between change in the target lobe volume and changes in volume and density variables in the other lobes. The target lobe volume at full inspiration in the treatment group had a mean reduction of -0.45 L (SE = 0.034, P < 0.0001), and was associated with volume increases in the ipsilateral lobe (rho = -0.68, P < 0.0001) and contralateral lung (rho = -0.16, P = 0.006), and overall reductions in expiratory RA (rho = 0.31, P < 0.0001) and residual volume (RV)/total lung capacity (TLC) (rho = 0.13, P = 0.03). When the volume of an emphysematous target lobe is reduced, the volume is redistributed primarily to the ipsilateral lobe, with an overall reduction. Image-based changes in lobar volumes and densities indicate that target lobe volume reduction is associated with statistically significant overall reductions in air trapping, consistent with expansion of the healthier lung. (orig.)

Emphysema lung lobe volume reduction: effects on the ipsilateral and contralateral lobes

International Nuclear Information System (INIS)

Brown, Matthew S.; Kim, Hyun J.; Abtin, Fereidoun G.; Galperin-Aizenberg, Maya; Pais, Richard; Da Costa, Irene G.; Ordookhani, Arash; Chong, Daniel; Ni, Chiayi; McNitt-Gray, Michael F.; Goldin, Jonathan G.; Strange, Charlie; Tashkin, Donald P.

2012-01-01

To investigate volumetric and density changes in the ipsilateral and contralateral lobes following volume reduction of an emphysematous target lobe. The study included 289 subjects with heterogeneous emphysema, who underwent bronchoscopic volume reduction of the most diseased lobe with endobronchial valves and 132 untreated controls. Lobar volume and low-attenuation relative area (RA) changes post-procedure were measured from computed tomography images. Regression analysis (Spearman's rho) was performed to test the association between change in the target lobe volume and changes in volume and density variables in the other lobes. The target lobe volume at full inspiration in the treatment group had a mean reduction of -0.45 L (SE = 0.034, P < 0.0001), and was associated with volume increases in the ipsilateral lobe (rho = -0.68, P < 0.0001) and contralateral lung (rho = -0.16, P = 0.006), and overall reductions in expiratory RA (rho = 0.31, P < 0.0001) and residual volume (RV)/total lung capacity (TLC) (rho = 0.13, P = 0.03). When the volume of an emphysematous target lobe is reduced, the volume is redistributed primarily to the ipsilateral lobe, with an overall reduction. Image-based changes in lobar volumes and densities indicate that target lobe volume reduction is associated with statistically significant overall reductions in air trapping, consistent with expansion of the healthier lung. (orig.)

Brain activity dynamics in human parietal regions during spontaneous switches in bistable perception.

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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.

Structural correlates of impaired working memory in hippocampal sclerosis

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Winston, Gavin P; Stretton, Jason; Sidhu, Meneka K; Symms, Mark R; Thompson, Pamela J; Duncan, John S

2013-01-01

Purpose: Temporal lobe epilepsy (TLE) has been considered to impair long-term memory, whilst not affecting working memory, but recent evidence suggests that working memory is compromised. Functional MRI (fMRI) studies demonstrate that working memory involves a bilateral frontoparietal network the activation of which is disrupted in hippocampal sclerosis (HS). A specific role of the hippocampus to deactivate during working memory has been proposed with this mechanism faulty in patients with HS. Structural correlates of disrupted working memory in HS have not been explored. Methods: We studied 54 individuals with medically refractory TLE and unilateral HS (29 left) and 28 healthy controls. Subjects underwent 3T structural MRI, a visuospatial n-back fMRI paradigm and diffusion tensor imaging (DTI). Working memory capacity assessed by three span tasks (digit span backwards, gesture span, motor sequences) was combined with performance in the visuospatial paradigm to give a global working memory measure. Gray and white matter changes were investigated using voxel-based morphometry and voxel-based analysis of DTI, respectively. Key Findings: Individuals with left or right HS performed less well than healthy controls on all measures of working memory. fMRI demonstrated a bilateral frontoparietal network during the working memory task with reduced activation of the right parietal lobe in both patient groups. In left HS, gray matter loss was seen in the ipsilateral hippocampus and parietal lobe, with maintenance of the gray matter volume of the contralateral parietal lobe associated with better performance. White matter integrity within the frontoparietal network, in particular the superior longitudinal fasciculus and cingulum, and the contralateral temporal lobe, was associated with working memory performance. In right HS, gray matter loss was also seen in the ipsilateral hippocampus and parietal lobe. Working memory performance correlated with the gray matter volume of

Subjective Cognitive Decline: Mapping Functional and Structural Brain Changes-A Combined Resting-State Functional and Structural MR Imaging Study.

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Sun, Yu; Dai, Zhengjia; Li, Yuxia; Sheng, Can; Li, Hongyan; Wang, Xiaoni; Chen, Xiaodan; He, Yong; Han, Ying

2016-10-01

Purpose To determine whether individuals with subjective cognitive decline (SCD) exhibit functional and structural brain alterations by using resting-state functional and structural magnetic resonance (MR) imaging. Materials and Methods This study received institutional review board approval, and all participants gave informed consent. Resting-state functional MR imaging and structural MR imaging techniques were used to measure amplitude of low-frequency fluctuations (ALFF) and regional gray matter volume in 25 subjects with SCD (mean age, 65.52 years ± 6.12) and 61 control subjects (mean age, 64.11 years ± 8.59). Voxel-wise general linear model analyses were used to examine between-group differences in ALFF or in gray matter volume and to further determine the brain-behavioral relationship. Results Subjects with SCD exhibited higher ALFF values than did control subjects in the bilateral inferior parietal lobule (left: 0.44 ± 0.25 vs 0.27 ± 0.18, respectively; P = .0003; right: 1.46 ± 0.45 vs 1.10 ± 0.37, respectively; P = .0015), right inferior (0.45 ± 0.15 vs 0.37 ± 0.08, repectively; P = .0106) and middle (1.03 ± 0.32 vs 0.83 ± 0.20, respectively; P = .0008) occipital gyrus, right superior temporal gyrus (0.11 ± 0.07 vs 0.07 ± 0.04, respectively; P = .0016), and right cerebellum posterior lobe (0.51 ± 0.27 vs 0.39 ± 0.15, respectively; P = .0010). In the SCD group, significant correlations were found between Auditory Verbal Learning Test recognition scores and ALFF in the left inferior parietal lobe (r = -0.79, P Learning Test immediate recall scores and ALFF values in the right middle occipital gyrus (r = -0.64, P = .002). Nonsignificant group differences were found in gray matter volume (P > .05, corrected). Conclusion Individuals with SCD had altered spontaneous functional activity, suggesting that resting-state functional MR imaging may be a noninvasive method for characterizing SCD. (©) RSNA, 2016 Online supplemental material is available for

The neocortical network representing associative memory reorganizes with time in a process engaging the anterior temporal lobe.

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Nieuwenhuis, Ingrid L C; Takashima, Atsuko; Oostenveld, Robert; McNaughton, Bruce L; Fernández, Guillén; Jensen, Ole

2012-11-01

During encoding, the distributed neocortical representations of memory components are presumed to be associatively linked by the hippocampus. With time, a reorganization of brain areas supporting memory takes place, which can ultimately result in memories becoming independent of the hippocampus. While it is theorized that with time, the neocortical representations become linked by higher order neocortical association areas, this remains to be experimentally supported. In this study, 24 human participants encoded sets of face-location associations, which they retrieved 1 or 25 h later ("recent" and "remote" conditions, respectively), while their brain activity was recorded using whole-head magnetoencephalography. We investigated changes in the functional interactions between the neocortical representational areas emerging over time. To assess functional interactions, trial-by-trial high gamma (60-140 Hz) power correlations were calculated between the neocortical representational areas relevant to the encoded information, namely the fusiform face area (FFA) and posterior parietal cortex (PPC). With time, both the FFA and the PPC increased their functional interactions with the anterior temporal lobe (ATL). Given that the ATL is involved in semantic representation of paired associates, our results suggest that, already within 25 h after acquiring new memory associations, neocortical functional links are established via higher order semantic association areas.

Spatial and verbal working memory: A functional magnetic resonance imaging study

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Blaž Koritnik

2004-08-01

Full Text Available According to numerous studies, working memory is not a unitary system. Baddeley's model of working memory includes besides central executive also two separate systems for verbal and visuo-spatial information processing. A modality- and process-specific specialization presumably exists in working memory system of the frontal lobes. In our preliminary study, we have used functional magnetic resonance imaging to study the pattern of cortical activation during spatial and verbal n-back task in six healthy subjects. A bilateral fronto-parietal cortical network was activated in both tasks. There was larger activation of right parietal and bilateral occipital areas in spatial than in vebal task. Activation of left sensorimotor area was larger in verbal compared to spatial task. No task-specific differences were found in the prefrontal cortex. Our results support the assumption that modality-specific processes exist within the working-memory system.

Structural and functional evaluation of cortical motor areas in Amyotrophic Lateral Sclerosis.

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Cosottini, Mirco; Pesaresi, Ilaria; Piazza, Selina; Diciotti, Stefano; Cecchi, Paolo; Fabbri, Serena; Carlesi, Cecilia; Mascalchi, Mario; Siciliano, Gabriele

2012-03-01

The structural and functional data gathered with Magnetic Resonance Imaging (MRI) techniques about the brain cortical motor damage in Amyotrophic Lateral Sclerosis (ALS) are controversial. In fact some structural MRI studies showed foci of gray matter (GM) atrophy in the precentral gyrus, even in the early stage, while others did not. Most functional MRI (fMRI) studies in ALS reported hyperactivation of extra-primary motor cortices, while contradictory results were obtained on the activation of the primary motor cortex. We aimed to investigate the cortical motor circuitries in ALS patients by a combined structural and functional approach. Twenty patients with definite ALS and 16 healthy subjects underwent a structural examination with acquisition of a 3D T1-weighted sequence and fMRI examination during a maximal force handgrip task executed with the right-hand, the left-hand and with both hands simultaneously. The T1-weighted images were analyzed with Voxel-Based Morphometry (VBM) that showed several clusters of reduced cortical GM in ALS patients compared to controls including the pre and postcentral gyri, the superior, middle and inferior frontal gyri, the supplementary motor area, the superior and inferior parietal cortices and the temporal lobe, bilaterally but more extensive on the right side. In ALS patients a significant hypoactivation of the primary sensory motor cortex and frontal dorsal premotor areas as compared to controls was observed. The hypoactivated areas matched with foci of cortical atrophy demonstrated by VBM. The fMRI analysis also showed an enhanced activation in the ventral premotor frontal areas and in the parietal cortex pertaining to the fronto-parietal motor circuit which paralleled with disease progression rate and matched with cortical regions of atrophy. The hyperactivation of the fronto-parietal circuit was asymmetric and prevalent in the left hemisphere. VBM and fMRI identified structural and functional markers of an extended

A Computational Model for the Automatic Diagnosis of Attention Deficit Hyperactivity Disorder Based on Functional Brain Volume

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Lirong Tan

2017-09-01

Full Text Available In this paper, we investigated the problem of computer-aided diagnosis of Attention Deficit Hyperactivity Disorder (ADHD using machine learning techniques. With the ADHD-200 dataset, we developed a Support Vector Machine (SVM model to classify ADHD patients from typically developing controls (TDCs, using the regional brain volumes as predictors. Conventionally, the volume of a brain region was considered to be an anatomical feature and quantified using structural magnetic resonance images. One major contribution of the present study was that we had initially proposed to measure the regional brain volumes using fMRI images. Brain volumes measured from fMRI images were denoted as functional volumes, which quantified the volumes of brain regions that were actually functioning during fMRI imaging. We compared the predictive power of functional volumes with that of regional brain volumes measured from anatomical images, which were denoted as anatomical volumes. The former demonstrated higher discriminative power than the latter for the classification of ADHD patients vs. TDCs. Combined with our two-step feature selection approach which integrated prior knowledge with the recursive feature elimination (RFE algorithm, our SVM classification model combining functional volumes and demographic characteristics achieved a balanced accuracy of 67.7%, which was 16.1% higher than that of a relevant model published previously in the work of Sato et al. Furthermore, our classifier highlighted 10 brain regions that were most discriminative in distinguishing between ADHD patients and TDCs. These 10 regions were mainly located in occipital lobe, cerebellum posterior lobe, parietal lobe, frontal lobe, and temporal lobe. Our present study using functional images will likely provide new perspectives about the brain regions affected by ADHD.

Medical image of the week: right middle lobe syndrome

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Cristan EA

2016-05-01

Full Text Available No abstract available. Article truncated at 150 words. A 73 year-old woman, a lifetime non-smoker, presented to the pulmonary clinic with chronic dyspnea on exertion and cough. Physical exam was unremarkable and pulmonary function testing showed normal spirometry. A chest radiograph revealed calcified mediastinal adenopathy and increased density in the right middle lobe region (Figure 1. A computed tomography scan of the chest revealed significant narrowing of the right middle lobe bronchus with partial atelectasis and prominent calcified mediastinal lymphadenopathy (Figure 2. Bronchoscopy showed no endobronchial lesions but there was evidence of extrinsic compression surrounding the right middle lobe orifice. An endobronchial biopsy revealed noncaseating granulomas. Bronchoscopy cultures and cytology were negative and this was presumed to be from a previous infection with histoplasmosis given the patient’s long-term residence in an endemic area. Given chronic narrowing of right middle lobe bronchus with persistent atelectasis of the right middle lobe, the patient was diagnosed with right middle lobe syndrome. ...

Resting-state, functional MRI on regional homogeneity changes of brain in the heavy smokers

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Yang Shiqi; Wu Guangyao; Lin Fuchun; Kong Xiangquan; Zhou Guofeng; Pang Haopeng; Zhu Ling; Liu Guobing; Lei Hao

2012-01-01

Objective: To explore the mechanism of self-awareness in the heavy smokers (HS) by using regional homogeneity (ReHo) combined with resting-state functional MRI (fMRI). Methods: Thirty HS and 31 healthy non-smokers (NS) matched for age and sex underwent a 3.0 T resting-state fMRI. The data were post-processed by SPM 5 and then the ReHo values were calculated by REST software. The ReHo values between the two groups were compared by two-sample t-test. The brain map with significant difference of ReHo value was obtained. Results: Compared with that in NS group, the regions with decreased ReHo value included the bilateral precuneus, superior frontal gyrus,medial prefrontal cortex, right angular gyrus, inferior frontal gyrus, inferior occipital gyrus, cerebellum, and left middle frontal gyrus in HS group. The regions of increased ReHo value included the bilateral insula, parahippocampal gyrus, white matter of parietal lobe, pons, left inferior parietal lobule, lingual gyrus, thalamus, inferior orbital gyrus, white matter of temporal-frontal lobe, and cerebellum. The difference was more obvious in the left hemisphere. Conclusions: In HS, abnormal ReHo on a resting state which reflects network of smoking addiction. This method may be helpful in understanding the mechanism of self-awareness in HS. (authors)

Case Report: A Rare Case Report of Frontal Lobe Syndrome

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Morteza Nouri- Khajavi

2003-04-01

Full Text Available The frontal lobe syndrome is a permanent personality change disorder with characteristic clinical pictures, which followed by frontal lobes damage. Clinical picture include: Affective instability, recurrent aggressive behavior, impaired social judgment, apathy and undifferentiating or suspiciousness and paranoid ideations. According DSM-IV classification frontal lobe syndrome named personality change due to head trauma on Axis I. Herein we report a case of 46 years-old man, who has developed behavioral disturbances following head trauma, about 10 years ago. Main clinical figures in this case are apathy, avolition and, undifferentiating. Clinical pictures are constant during these 10 years. The diagnostic approach has been based on patient’s problems history which, has taken from his family, mental status examination, Neurological examination, Brain imaging and Neuropsychological assessments which related to frontal lobes function. Because of rarity & neglection due to mysterious function of frontal lobes, and also considering that personality change from previous level is prominent figure of this syndrome and also brain imaging findings, which compatible with clinical findings, with this aim, we have reported this case.

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

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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.

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

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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...

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.

Parietal cells?new perspectives in glomerular disease

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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...

Immunohistochemical study of Metallothionein in patients with temporal lobe epilepsy.

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Juárez-Rebollar, Daniel; Alonso-Vanegas, Mario; Nava-Ruíz, Concepción; Buentello-García, Masao; Yescas-Gómez, Petra; Díaz-Ruíz, Araceli; Rios, Camilo; Méndez-Armenta, Marisela

2017-05-01

Epilepsy is characterized by spontaneous recurrent seizures and temporal lobe epilepsy (TLE) is the most common serious neurological example of acquired and frequent epilepsy. Oxidative stress is recognized as playing a contributing role in several neurological disorders, and most recently have been implicated in acquired epilepsies. The MTs occur in several brain regions and may serve as neuroprotective proteins against reactive oxygen species causing oxidative damage and stress. The main aim of this work was to describe the immunohistochemical localization of MT in the specimens derived from the patients affected by TLE. Histopathological examination showed NeuN, GFAP and MT immunopositive cells that were analyzed for determinate in hippocampal and parietal cortex samples. An increase in the reactive gliosis associated with increased MT expression was observed in patients with TLE. Copyright © 2016 Elsevier Ltd. All rights reserved.

Brain regional homogeneity changes following transjugular intrahepatic portosystemic shunt in cirrhotic patients support cerebral adaptability theory—A resting-state functional MRI study

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Ni, Ling; Qi, Rongfeng [Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002 (China); Zhang, Long Jiang, E-mail: kevinzhlj@163.com [Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002 (China); Zhong, Jianhui [Department of Biomedical Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zheng, Gang [Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002 (China); Wu, Xingjiang; Fan, Xinxin [Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002 (China); Lu, Guang Ming, E-mail: cjr.luguangming@vip.163.com [Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002 (China)

2014-03-15

Purpose: The exact neuro-pathophysiological effect of transjugular intrahepatic portosystemic shunt (TIPS) on brain function remains unclear. The purpose of this study was to investigate the longitudinal brain activity changes in cirrhotic patients with TIPS insertion using resting-state functional MRI (fMRI) with regional homogeneity (ReHo) method. Methods: Fifteen cirrhotic patients without overt hepatic encephalopathy (OHE) planned for TIPS procedure and 15 age- and gender-matched healthy controls were included in this study. Eleven of the 15 patients underwent repeated fMRI examinations at median 7-day following TIPS, 8 patients in median 3-month, and 7 patients in median 1-year follow-up duration, respectively. Regional homogeneity was calculated by the Kendall's coefficient of concordance (KCC) and compared between patients before TIPS and healthy controls with two-sample t test as well as pre-and post-TIPS patients with paired t test. Correlations between the pre- and post-TIPS changes of ReHo and the changes of venous blood ammonia level and number connection test type A (NCT-A)/digit symbol test (DST) scores were calculated by crossing subjects. Results: Compared with healthy controls, 15 cirrhotic patients before TIPS procedure showed decreased ReHo in the bilateral frontal, parietal, temporal and occipital lobes and increased ReHo in the bilateral caudate. Compared with the pre-TIPS patients, 11 post-TIPS patients in the median 7-day follow-up examinations demonstrated decreased ReHo in the medial frontal gyrus (MFG), superior parietal gyrus (SPG), middle/superior temporal gyrus (M/STG), anterior cingulate cortex (ACC), caudate, and increased ReHo in the insula. Eight post-TIPS patients in the median 3-month follow-up examinations showed widespread decreased ReHo in the bilateral frontal and parietal lobes, ACC, caudate, and increased ReHo in the insula and precuneus/cuneus. In the median 1-year follow-up studies, seven post-TIPS patients displayed

Brain regional homogeneity changes following transjugular intrahepatic portosystemic shunt in cirrhotic patients support cerebral adaptability theory—A resting-state functional MRI study

International Nuclear Information System (INIS)

Ni, Ling; Qi, Rongfeng; Zhang, Long Jiang; Zhong, Jianhui; Zheng, Gang; Wu, Xingjiang; Fan, Xinxin; Lu, Guang Ming

2014-01-01

Purpose: The exact neuro-pathophysiological effect of transjugular intrahepatic portosystemic shunt (TIPS) on brain function remains unclear. The purpose of this study was to investigate the longitudinal brain activity changes in cirrhotic patients with TIPS insertion using resting-state functional MRI (fMRI) with regional homogeneity (ReHo) method. Methods: Fifteen cirrhotic patients without overt hepatic encephalopathy (OHE) planned for TIPS procedure and 15 age- and gender-matched healthy controls were included in this study. Eleven of the 15 patients underwent repeated fMRI examinations at median 7-day following TIPS, 8 patients in median 3-month, and 7 patients in median 1-year follow-up duration, respectively. Regional homogeneity was calculated by the Kendall's coefficient of concordance (KCC) and compared between patients before TIPS and healthy controls with two-sample t test as well as pre-and post-TIPS patients with paired t test. Correlations between the pre- and post-TIPS changes of ReHo and the changes of venous blood ammonia level and number connection test type A (NCT-A)/digit symbol test (DST) scores were calculated by crossing subjects. Results: Compared with healthy controls, 15 cirrhotic patients before TIPS procedure showed decreased ReHo in the bilateral frontal, parietal, temporal and occipital lobes and increased ReHo in the bilateral caudate. Compared with the pre-TIPS patients, 11 post-TIPS patients in the median 7-day follow-up examinations demonstrated decreased ReHo in the medial frontal gyrus (MFG), superior parietal gyrus (SPG), middle/superior temporal gyrus (M/STG), anterior cingulate cortex (ACC), caudate, and increased ReHo in the insula. Eight post-TIPS patients in the median 3-month follow-up examinations showed widespread decreased ReHo in the bilateral frontal and parietal lobes, ACC, caudate, and increased ReHo in the insula and precuneus/cuneus. In the median 1-year follow-up studies, seven post-TIPS patients displayed

Transcriptional landscape of glomerular parietal epithelial cells.

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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.

Modified Functional Superficial Parotidectomy With Ligation of the Major Branch of the Parotid Duct Extending to the Superficial Lobe.

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Chang, Jung Woo; Leem, Soo Seong; Choi, Hwan Jun; Lee, Jang Hyun

2017-05-01

A functional superficial parotidectomy can maintain salivary function by preserving the Stensen duct. However, this technique still brings the possibility of salivary leakage, because major branches of the parotid duct from the resected site do not get ligated. To reduce this complication, this study introduces a modified technique with major branch ligation. From December 2008 to February 2015, 14 patients who underwent superficial parotidectomy were divided into 2 groups. Group A was treated with the modified functional superficial parotidectomy involving the major branch between the superficial lobe and parotid duct. Group B was treated with the conventional superficial parotidectomy without involving the major branch of the parotid duct. The clinical complications, period of Hemovac usage, and surgical duration were noted in each group. Two of 8 patients in group A had a major branch from Stensen duct that was ligated, and there was no evidence of salivary leakage or sialocele in any of the patients of group A, whereas group B contained 2 cases of salivary leakage, one of which became sialocele. Group A had a significantly longer Hemovac maintenance period than group B (P < 0.05), and the duration of surgery was also significantly different between the 2 groups (P < 0.05). Because a solitary major branch of the main parotid duct occasionally extends toward the superficial lobe, our modified technique-functional superficial parotidectomy with ligation of the major branch toward the superficial lobe-is a useful option for treatment of a benign parotid mass in such cases.

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

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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

Image formation of brain function in patients suffering from knee osteoarthritis treated with moxibustion.

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Xie, Hongwu; Xu, Fangming; Chen, Rixin; Luo, Tianyou; Chen, Mingren; Fang, Weidong; Lü, Fajin; Wu, Fei; Song, Yune; Xiong, Jun

2013-04-01

Functional magnetic resonance imaging (fMRI) technology was used to study changes to the resting state blood flow in the brains of patients with knee osteoarthritis (KOA) before and after treatment with moxibustion at the acupoint of the left Dubi (ST 35) and to probe the cerebral mechanism underlying the effect of moxibustion. The resting state brain function of 30 patients with left KOA was scanned with fMRI before and after treatment with moxibustion. The analytic methods of fractional amplitude of low frequency fluctuation (fALFF) and regional homogeneity (ReHo) were used to observe changes in resting state brain function. The fALFF values of the right cerebrum, extra-nucleus, left cerebellum, left cerebrum and white matter of patients after moxibustion treatment were higher than before treatment, and the fALFF values of the precentral gyrus, frontal lobe and occipital lobe were lower than before treatment (P or = 85). The ReHo values of the thalamus, extra-nucleus and parietal lobe of patients were much higher than those before moxibustion treatment, and the ReHo values of the right cerebrum, left cerebrum and frontal lobe were lower than before treatment (P or = 85). The influence of moxibustion on obvious changes in brain regions basically conforms to the way that pain and warmth is transmitted in the body, and the activation of sensitive systems in the body may be objective evidence of channel transmission. The regulation of brain function by moxibustion is not in a single brain region but rather in a network of many brain regions.

A Curious Lobe

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Andréa Chabot-Naud

2011-01-01

Full Text Available A case of azygos lobe is presented. An azygos lobe is an accessory lobe of the lung that may occasionally be confused with a pathological process such as a bulla, lung abscess or neoplasm. Its pathogenesis is discussed, as are the characteristic x-ray features that enable an accurate diagnosis.

Ipsiversive ictal eye deviation in inferioposterior temporal lobe epilepsy-Two SEEG cases report.

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Zhang, Wei; Liu, Xingzhou; Zuo, Lijun; Guo, Qiang; Chen, Qi; Wang, Yongjun

2017-02-21

Versive seizure characterized by conjugate eye movement during epileptic seizure has been considered commonly as one of the most valuable semiological signs for epilepsy localization, especially for frontal lobe epilepsy. However, the lateralizing and localizing significance of ictaleye deviation has been questioned by clinical observation of a series of focal epilepsy studies, including frontal, central, temporal, parietal and occipital epilepsy. Two epileptic cases characterized by ipsiversive eye deviation as initial clinical sign during the habitual epileptic seizures are presented in this paper. The localization of the epileptogenic zone of both of the cases has been confirmed as inferioposterior temporal region by the findings of ictalstereoelectroencephalography (SEEG) and a good result after epileptic surgery. Detailed analysis of the exact position of the key contacts of the SEEG electrodes identified the overlap between the location of the epileptogenic zone and human MT/MST complex, which play a crucial role in the control of smooth pursuit eye movement. Ipsiversive eye deviation could be the initial clinical sign of inferioposterior temporal lobe epilepsy and attribute to the involvement of human MT/MST complex, especially human MST whichwas located on the anterior/dorsal bank of the anterior occipital sulcus (AOS).

Study of diffusion tensor imaging in subcortical ischemic vascular cognitive impairment

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Hui-ying GUO

2014-04-01

Full Text Available Objective Using diffusion tensor imaging (DTI to explore the microstructure changes of white matter in subcortical ischemic vascular cognitive impairment (SIVCI and its correlation with cognitive function.  Methods Forty-nine patients with subcortical ischemic cerebrovascular diseases were collected. By using Clinical Dementia Rating Scale (CDR, they were classified into 10 cases of vascular dementia (VaD group, 20 cases of vascular cognitive impairment-no dementia (VCIND group and 19 cases of normal cognitive function (control group. Conventional MRI and DTI were performed in all cases. Based on the DTI data, voxel-based analysis was used to assess the whole brain region. Correlation analysis was applied to illustrate the relationship between DTI parameters and cognitive scale in VaD patients.  Results Compared with the control group, fractional anisotropy (FA values of patients in VaD group decreased in medial prefrontal cortex, anterior cingulate cortex, corpus callosum stem, bilateral parietal lobes, right temporal lobe and bilateral orbitofrontal lobes (P = 0.000, for all, and FA values of patients in VCIND group decreased in right inferior frontal gyrus, right hippocampus and bilateral precuneus (P = 0.000, for all. Compared with VCIND group, FA values of patients in VaD group decreased in medial prefrontal cortex, anterior cingulate, corpus callosum, bilateral parietal lobes and right temporal lobe (P = 0.000, for all. Compared with the control group, mean diffusivity (MD values in VaD group increased in medial prefrontal cortex, corpus callosum, bilateral parietal lobes, bilateral temporal lobes and anterior cingulate (P = 0.000, for all, while in VCIND group increased in bilateral precuneus and right hippocampus (P = 0.000, for all. Compared with VCIND group, MD values in VaD group increased in right medial prefrontal cortex, anterior cingulate cortex, corpus callosum stem, bilateral parietal lobes and bilateral temporal lobes (P = 0

Research on spontaneous activity in adult anisometropic amblyopia with regional homogeneity

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Huang, Yufeng; Zhou, Yifeng

2017-06-01

Amblyopia usually occurs in early childhood and results in monocular visual impairment. The functional magnetic resonance imaging (fMRI) studies have reflected functional anomaly in amblyopia. In resting-state fMRI study, spontaneous activity changes abnormally in anisometropic amblyopia could be revealed by the regional homogeneity (ReHo). Twenty two adult anisometropic amblyopes and Twenty one normal controls participated in this fMRI study. Two sample T test was carried out to analysis ReHo within the whole brain for the inter groups. Compare with normal group, our study found that the amblyopia’s ReHo mainly increased in the left frontal lobe, while decreased in the left cerebellum, the temporal lobe (left and right), and the left parietal lobe. And the ReHo values in middle and inferior temporal lobe, the prefrontal lobe, frontal lobe (positive) and parietal lobe and medial frontal gyrus (negative) could be correlated with the acuity deficit of amblyopia. The results increased in ReHo may indicate compensatory plasticity in higher vision information process, while the decreased in ReHo may reflect decreased ability in eye movement, spatial sense and visuo-motor coordination. The correlation revealed that the vision deficit may correspond to the spontaneous in certain brain area.

The Anterolateral Limit of the Occipital Lobe: An Anatomical and Imaging Study.

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Reis, Cassius Vinicius C; Yagmurlu, Kaan; Elhadi, Ali M; Dru, Alexander; Lei, Ting; Gusmão, Sebastião N S; Tazinaffo, Uédson; Zabramski, Joseph M; Spetzler, Robert F; Preul, Mark C

2016-12-01

Objectives  The boundaries of the temporal lobe, the parietal lobe, and the anterior portion of the occipital lobe (OL) are poorly defined. Lesions in these areas can be difficult to localize. Therefore, we studied the anterolateral limit of the OL to identify reliable anatomical landmarks. Design  In 10 formalin-fixed cadaveric heads, the boundaries of the OL and relative anatomical landmarks were studied. Main Outcome Measures  Distances between the following structures were measured: (1) preoccipital tentorial plica (POTP) to the junction between lambdoid suture and superior border of the transverse sinus (POTP-SL), (2) POTP to the sinodural angle of Citelli (POTP-PP), (3) lambda to parietooccipital sulcus (L-POS), and (4) preoccipital notch to termination of the vein of Labbé (PON-VL). Landmarks in 559 computed tomography and magnetic resonance images were also studied. Results  The POTP was found on the tentorium of all anatomical specimens, located at the same coronal level as the PON and its attachment to the bony protuberance (BP) at the lateral cranial wall. The mean distances were POTP-SL, 6.5 ± 6.4 mm; POTP-PP, 18.1 ± 7.8 mm; L-POS, 10.8 ± 5.0 mm; and PON-VL, 8.8 ± 10.1 mm. Conclusion  Osseous (asterion, lambda, and BP), dural (POTP), and vascular (VL) landmarks can be used as reference structures to identify the anterolateral limit of the OL.

Cognitive function and MRI findings in very low birth weight infants

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Imamura, Atsuko; Takagishi, Yuka; Takada, Satoru; Uetani, Yoshiyuki; Nakamura, Toru; Nakamura, Hajime; Inagaki, Yuko.

1996-01-01

Twenty-two very low birth weight infants at preschool ages of 5-6 years were studied to clarify the correlation between cognitive function and MRI findings. Cognitive function was evaluated by the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Frostig developmental test of visual perception. Ventricular enlargement, assessed by the bioccipital index (B.I.) measured on MRI, was correlated to cognitive disorders. Children with periventricular high intensity areas (T 2 -weighted images) extending from the posterior periventricular region to the parietal lobe tend to highly suffer from cerebral palsy and visuoperceptual impairment. These results indicate that the disorders of cognitive function in very low birth weight infants were caused by a damage of association fibers in periventricular areas which was detectable by MRI. (author)

The Structural Plasticity of White Matter Networks Following Anterior Temporal Lobe Resection

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Yogarajah, Mahinda; Focke, Niels K.; Bonelli, Silvia B.; Thompson, Pamela; Vollmar, Christian; McEvoy, Andrew W.; Alexander, Daniel C.; Symms, Mark R.; Koepp, Matthias J.; Duncan, John S.

2010-01-01

Anterior temporal lobe resection is an effective treatment for refractory temporal lobe epilepsy. The structural consequences of such surgery in the white matter, and how these relate to language function after surgery remain unknown. We carried out a longitudinal study with diffusion tensor imaging in 26 left and 20 right temporal lobe epilepsy…

Automatic extraction analysis of the anatomical functional area for normal brain 18F-FDG PET imaging

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Guo Wanhua; Jiang Xufeng; Zhang Liying; Lu Zhongwei; Li Peiyong; Zhu Chengmo; Zhang Jiange; Pan Jiapu

2003-01-01

Using self-designed automatic extraction software of brain functional area, the grey scale distribution of 18 F-FDG imaging and the relationship between the 18 F-FDG accumulation of brain anatomic function area and the 18 F-FDG injected dose, the level of glucose, the age, etc., were studied. According to the Talairach coordinate system, after rotation, drift and plastic deformation, the 18 F-FDG PET imaging was registered into the Talairach coordinate atlas, and then the average gray value scale ratios between individual brain anatomic functional area and whole brain area was calculated. Further more the statistics of the relationship between the 18 F-FDG accumulation of every brain anatomic function area and the 18 F-FDG injected dose, the level of glucose and the age were tested by using multiple stepwise regression model. After images' registration, smoothing and extraction, main cerebral cortex of the 18 F-FDG PET brain imaging can be successfully localized and extracted, such as frontal lobe, parietal lobe, occipital lobe, temporal lobe, cerebellum, brain ventricle, thalamus and hippocampus. The average ratios to the inner reference of every brain anatomic functional area were 1.01 ± 0.15. By multiple stepwise regression with the exception of thalamus and hippocampus, the grey scale of all the brain functional area was negatively correlated to the ages, but with no correlation to blood sugar and dose in all areas. To the 18 F-FDG PET imaging, the brain functional area extraction program could automatically delineate most of the cerebral cortical area, and also successfully reflect the brain blood and metabolic study, but extraction of the more detailed area needs further investigation

Effectiveness of cognitive-coping therapy and alteration of resting-state brain function in obsessive-compulsive disorder.

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Zhao, Hong-Zeng; Wang, Chang-Hong; Gao, Zhong-Zhan; Ma, Jian-Dong; Huang, Ping; Li, Heng-Fen; Sang, De-En; Shan, Xiao-Wen; Kou, Shao-Jie; Li, Zhi-Rong; Ma, Li; Zhang, Zhao-Hui; Zhang, Jian-Hong; Ouyang, Hua; Lian, Hong-Kai; Zang, Yu-Feng; Hu, Xian-Zhang

2017-01-15

Cognitive-coping therapy (CCT), integrating cognitive theory with stress-coping theory, is an efficacious therapy for obsessive-compulsive disorder (OCD). However, the potential brain mediation for the effectiveness remains unclear. We sought to investigate differences of resting-state brain function between OCD and healthy controls and if such differences would be changed by a four-week CCT. Thirty-one OCD patients were recruited and randomized into CCT (n=15) and pharmacotherapy plus CCT (pCCT, n=16) groups, together with 25 age-, gender- and education-matched healthy controls. The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) was scored to evaluate the severity in symptoms. Resting-state functional magnetic resonance imaging was scanned pre- and post-treatment. For patients, Y-BOCS scores were reduced during four-week treatment for CCT and pCCT (Pleft hippocampus, parahippocampus, and temporal lobes, but lower in the right orbitofrontal cortex, rectus, bilateral calcarine, cuneus, lingual, occipital, left parietal, postcentral, precentral, and parietal (corrected Pbrain function was different between OCD and controls; such differences disappeared after OCD symptoms were relieved. Copyright © 2016 Elsevier B.V. All rights reserved.

The Opioid System in Temporal Lobe Epilepsy: Functional Role and Therapeutic Potential

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Johannes Burtscher

2017-08-01

Full Text Available Temporal lobe epilepsy is considered to be one of the most common and severe forms of focal epilepsies. Patients often develop cognitive deficits and emotional blunting along the progression of the disease. The high incidence of resistance to antiepileptic drugs and a frequent lack of admissibility to surgery poses an unmet medical challenge. In the urgent quest of novel treatment strategies, neuropeptides are interesting candidates, however, their therapeutic potential has not yet been exploited. This review focuses on the functional role of the endogenous opioid system with respect to temporal lobe epilepsy, specifically in the hippocampus. The role of dynorphins and kappa opioid receptors (KOPr as modulators of neuronal excitability is well understood: both the reduced release of glutamate as well of postsynaptic hyperpolarization were shown in glutamatergic neurons. In line with this, low levels of dynorphin in humans and mice increase the risk of epilepsy development. The role of enkephalins is not understood so well. On one hand, some agonists of the delta opioid receptors (DOPr display pro-convulsant properties probably through inhibition of GABAergic interneurons. On the other hand, enkephalins play a neuro-protective role under hypoxic or anoxic conditions, most probably through positive effects on mitochondrial function. Despite the supposed absence of endorphins in the hippocampus, exogenous activation of the mu opioid receptors (MOPr induces pro-convulsant effects. Recently-expanded knowledge of the complex ways opioid receptors ligands elicit their effects (including biased agonism, mixed binding, and opioid receptor heteromers, opens up exciting new therapeutic potentials with regards to seizures and epilepsy. Potential adverse side effects of KOPr agonists may be minimized through functional selectivity. Preclinical data suggest a high potential of such compounds to control seizures, with a strong predictive validity toward human

A functional magnetic resonance imaging study mapping the episodic memory encoding network in temporal lobe epilepsy

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Sidhu, Meneka K.; Stretton, Jason; Winston, Gavin P.; Bonelli, Silvia; Centeno, Maria; Vollmar, Christian; Symms, Mark; Thompson, Pamela J.; Koepp, Matthias J.

2013-01-01

Functional magnetic resonance imaging has demonstrated reorganization of memory encoding networks within the temporal lobe in temporal lobe epilepsy, but little is known of the extra-temporal networks in these patients. We investigated the temporal and extra-temporal reorganization of memory encoding networks in refractory temporal lobe epilepsy and the neural correlates of successful subsequent memory formation. We studied 44 patients with unilateral temporal lobe epilepsy and hippocampal sclerosis (24 left) and 26 healthy control subjects. All participants performed a functional magnetic resonance imaging memory encoding paradigm of faces and words with subsequent out-of-scanner recognition assessments. A blocked analysis was used to investigate activations during encoding and neural correlates of subsequent memory were investigated using an event-related analysis. Event-related activations were then correlated with out-of-scanner verbal and visual memory scores. During word encoding, control subjects activated the left prefrontal cortex and left hippocampus whereas patients with left hippocampal sclerosis showed significant additional right temporal and extra-temporal activations. Control subjects displayed subsequent verbal memory effects within left parahippocampal gyrus, left orbitofrontal cortex and fusiform gyrus whereas patients with left hippocampal sclerosis activated only right posterior hippocampus, parahippocampus and fusiform gyrus. Correlational analysis showed that patients with left hippocampal sclerosis with better verbal memory additionally activated left orbitofrontal cortex, anterior cingulate cortex and left posterior hippocampus. During face encoding, control subjects showed right lateralized prefrontal cortex and bilateral hippocampal activations. Patients with right hippocampal sclerosis showed increased temporal activations within the superior temporal gyri bilaterally and no increased extra-temporal areas of activation compared with

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.

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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

Reasoning, learning, and creativity: frontal lobe function and human decision-making.

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Anne Collins

Full Text Available The frontal lobes subserve decision-making and executive control--that is, the selection and coordination of goal-directed behaviors. Current models of frontal executive function, however, do not explain human decision-making in everyday environments featuring uncertain, changing, and especially open-ended situations. Here, we propose a computational model of human executive function that clarifies this issue. Using behavioral experiments, we show that unlike others, the proposed model predicts human decisions and their variations across individuals in naturalistic situations. The model reveals that for driving action, the human frontal function monitors up to three/four concurrent behavioral strategies and infers online their ability to predict action outcomes: whenever one appears more reliable than unreliable, this strategy is chosen to guide the selection and learning of actions that maximize rewards. Otherwise, a new behavioral strategy is tentatively formed, partly from those stored in long-term memory, then probed, and if competitive confirmed to subsequently drive action. Thus, the human executive function has a monitoring capacity limited to three or four behavioral strategies. This limitation is compensated by the binary structure of executive control that in ambiguous and unknown situations promotes the exploration and creation of new behavioral strategies. The results support a model of human frontal function that integrates reasoning, learning, and creative abilities in the service of decision-making and adaptive behavior.

Reasoning, learning, and creativity: frontal lobe function and human decision-making.

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Collins, Anne; Koechlin, Etienne

2012-01-01

The frontal lobes subserve decision-making and executive control--that is, the selection and coordination of goal-directed behaviors. Current models of frontal executive function, however, do not explain human decision-making in everyday environments featuring uncertain, changing, and especially open-ended situations. Here, we propose a computational model of human executive function that clarifies this issue. Using behavioral experiments, we show that unlike others, the proposed model predicts human decisions and their variations across individuals in naturalistic situations. The model reveals that for driving action, the human frontal function monitors up to three/four concurrent behavioral strategies and infers online their ability to predict action outcomes: whenever one appears more reliable than unreliable, this strategy is chosen to guide the selection and learning of actions that maximize rewards. Otherwise, a new behavioral strategy is tentatively formed, partly from those stored in long-term memory, then probed, and if competitive confirmed to subsequently drive action. Thus, the human executive function has a monitoring capacity limited to three or four behavioral strategies. This limitation is compensated by the binary structure of executive control that in ambiguous and unknown situations promotes the exploration and creation of new behavioral strategies. The results support a model of human frontal function that integrates reasoning, learning, and creative abilities in the service of decision-making and adaptive behavior.

Brain activation for response inhibition under gaming cue distraction in internet gaming disorder

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Gin-Chung Liu

2014-01-01

Full Text Available We evaluated neural substrates related to the loss of control in college students with internet gaming disorder (IGD. We hypothesized that deficit in response inhibition under gaming cue distraction was the possible mechanism for the loss of control internet use. Eleven cases of IGD and 11 controls performed Go/NoGo tasks with/without gaming distraction in the functional magnetic resonance imaging scanner. When the gaming picture was shown as background while individuals were performing Go/NoGo tasks, the IGD group committed more commission errors. The control group increased their brain activations more over the right dorsolateral prefrontal cortex (DLPFC and superior parietal lobe under gaming cue distraction in comparison with the IGD group. Furthermore, brain activation of the right DLPFC and superior parietal lobe were negatively associated with performance of response inhibition among the IGD group. The results suggest that the function of response inhibition was impaired under gaming distraction among the IGD group, and individuals with IGD could not activate right DLPFC and superior parietal lobe to keep cognitive control and attention allocation for response inhibition under gaming cue distraction. This mechanism should be addressed in any intervention for IGD.

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.

Visual and auditory reaction time for air traffic controllers using quantitative electroencephalograph (QEEG) data.

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Abbass, Hussein A; Tang, Jiangjun; Ellejmi, Mohamed; Kirby, Stephen

2014-12-01

The use of quantitative electroencephalograph in the analysis of air traffic controllers' performance can reveal with a high temporal resolution those mental responses associated with different task demands. To understand the relationship between visual and auditory correct responses, reaction time, and the corresponding brain areas and functions, air traffic controllers were given an integrated visual and auditory continuous reaction task. Strong correlations were found between correct responses to the visual target and the theta band in the frontal lobe, the total power in the medial of the parietal lobe and the theta-to-beta ratio in the left side of the occipital lobe. Incorrect visual responses triggered activations in additional bands including the alpha band in the medial of the frontal and parietal lobes, and the Sensorimotor Rhythm in the medial of the parietal lobe. Controllers' responses to visual cues were found to be more accurate but slower than their corresponding performance on auditory cues. These results suggest that controllers are more susceptible to overload when more visual cues are used in the air traffic control system, and more errors are pruned as more auditory cues are used. Therefore, workload studies should be carried out to assess the usefulness of additional cues and their interactions with the air traffic control environment.

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

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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.

Synaesthetic colour in the brain: beyond colour areas. A functional magnetic resonance imaging study of synaesthetes and matched controls.

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van Leeuwen, Tessa M; Petersson, Karl Magnus; Hagoort, Peter

2010-08-10

In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour). Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. First, in a free viewing functional magnetic resonance imaging (fMRI) experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction) also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent) response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal cortex is likely to play an important role, may induce V4 activation and the percept of

Synaesthetic colour in the brain: beyond colour areas. A functional magnetic resonance imaging study of synaesthetes and matched controls.

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Tessa M van Leeuwen

Full Text Available BACKGROUND: In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour. Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. METHODOLOGY/PRINCIPAL FINDINGS: First, in a free viewing functional magnetic resonance imaging (fMRI experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. CONCLUSIONS/SIGNIFICANCE: Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal

Alterations in conflict monitoring are related to functional connectivity in Parkinson's disease.

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Rosenberg-Katz, Keren; Maidan, Inbal; Jacob, Yael; Giladi, Nir; Mirelman, Anat; Hausdorff, Jeffrey M

2016-09-01

Patients with Parkinson's disease (PD) have difficulties in executive functions including conflict monitoring. The neural mechanisms underlying these difficulties are not yet fully understood. In order to examine the neural mechanisms related to conflict monitoring in PD, we evaluated 35 patients with PD and 20 healthy older adults while they performed a word-color Stroop paradigm in the MRI. Specifically, we focused on changes between the groups in task-related functional connectivity using psycho-physiological interaction (PPI) analysis. The anterior cingulate cortex (ACC), which is a brain node previously associated with the Stroop paradigm, was selected as the seed region for this analysis. Patients with PD, as compared to healthy controls, had reduced task-related functional connectivity between the ACC and parietal regions including the precuneus and inferior parietal lobe. This was seen only in the incongruent Stroop condition. A higher level of connectivity between the ACC and precuneus was correlated with a lower error rate in the conflicting, incongruent Stroop condition in the healthy controls, but not in the patients with PD. Furthermore, the patients also had reduced functional connectivity between the ACC and the superior frontal gyrus which was present in both the incongruent and congruent task condition. The present findings shed light on brain mechanisms that are apparently associated with specific cognitive difficulties in patients with PD. Among patients with PD, impaired conflict monitoring processing within the ACC-based fronto-parietal network may contribute to difficulties under increased executive demands. Copyright © 2016 Elsevier Ltd. All rights reserved.

The parietal cell gastric H, K-ATPase also functions as the Na, K-ATPase and Ca-ATPase in altered states.

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Ray, Tushar

2013-01-01

This article offers an explanation for the apparent lack of Na, K-ATPase activity in parietal cells although ouabain has been known to inhibit gastric acid secretion since 1962. The gastric H, K-ATPase (proton-pump) seems to be acting in altered states, thus behaving like a Na, K-ATPase (Na-pump) and/or Ca-ATPase (Ca-pump) depending on cellular needs.  This conclusion is based on the following findings. First, parietal cell fractions do not exhibit Na, K-ATPase activity at pH 7.0 but do at pH 8.5. Second, the apical plasma membrane (APM) fraction exhibits a (Ca or Mg)-ATPase activity with negligible H, K-ATPase activity. However, when assayed with Mg alone in presence of the 80 k Da cytosolic proton-pump activator (HAF), the APM fraction reveals remarkably high H, K-ATPase activity, suggesting the observed low affinity of Ca (or Mg)-ATPase is an altered state of the latter. Third, calcium (between 1 and 4 µM) shows both stimulation and inhibition of the HAF-stimulated H, K-ATPase depending on its concentration, revealing a close interaction between the  proton-pump activator and local Ca concentration in gastric H, K-ATPase function. Such interactions suggest that Ca is acting as a terminal member of the intracellular signaling system for the HAF-regulated proton-pump. It appears that during resting state, the HAF-associated H, K-ATPase remains inhibited by Ca (>1 µM) and, prior to resumption of acid secretion the gastric H, K-ATPase acts temporarily as a Ca-pump for removing excess Ca from its immediate environment. This conclusion is consistent with the recent reports of immunochemical co-localization of the gastric H, K-ATPase and Ca-ATPase by superimposition in parietal cells, and a transitory efflux of Ca immediately preceding the onset of acid secretion. These new perspectives on proton-pump function would open new avenues for a fuller understanding of the intracellular regulation of the ubiquitous Na-pump.

Changes in frontal-parietal activation and math skills performance following adaptive number sense training: preliminary results from a pilot study.

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Kesler, Shelli R; Sheau, Kristen; Koovakkattu, Della; Reiss, Allan L

2011-08-01

Number sense is believed to be critical for math development. It is putatively an implicitly learned skill and may therefore have limitations in terms of being explicitly trained, particularly in individuals with altered neurodevelopment. A case series study was conducted using an adaptive, computerised programme that focused on number sense and general problem-solving skills. The study was designed to investigate training effects on performance as well as brain function in a group of children with Turner syndrome who are at risk for math difficulties and altered development of math-related brain networks. Standardised measurements of math and math-related cognitive skills as well as functional magnetic resonance imaging (fMRI) were used to assess behavioural and neurobiological outcomes following training. Participants demonstrated significantly increased basic math skills, including number sense, and calculation as well as processing speed, cognitive flexibility and visual-spatial processing skills. With the exception of calculation, increased scores also were clinically significant (i.e., recovered) based on reliable change analysis. Participants additionally demonstrated significantly increased bilateral parietal lobe activation and decreased frontal-striatal and mesial temporal activation following the training programme. These findings show proof of concept for an accessible training approach that may be potentially associated with improved number sense, math and related skills, as well as functional changes in math-related neural systems, even among individuals at risk for altered brain development.

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

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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.

Temporal lobe surgery in childhood and neuroanatomical predictors of long-term declarative memory outcome

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Skirrow, Caroline; Cross, J. Helen; Harrison, Sue; Cormack, Francesca; Harkness, William; Coleman, Rosie; Meierotto, Ellen; Gaiottino, Johanna; Vargha-Khadem, Faraneh

2015-01-01

The temporal lobes play a prominent role in declarative memory function, including episodic memory (memory for events) and semantic memory (memory for facts and concepts). Surgical resection for medication-resistant and well-localized temporal lobe epilepsy has good prognosis for seizure freedom, but is linked to memory difficulties in adults, especially when the removal is on the left side. Children may benefit most from surgery, because brain plasticity may facilitate post-surgical reorganization, and seizure cessation may promote cognitive development. However, the long-term impact of this intervention in children is not known. We examined memory function in 53 children (25 males, 28 females) who were evaluated for epilepsy surgery: 42 underwent unilateral temporal lobe resections (25 left, 17 right, mean age at surgery 13.8 years), 11 were treated only pharmacologically. Average follow-up was 9 years (range 5–15). Post-surgical change in visual and verbal episodic memory, and semantic memory at follow-up were examined. Pre- and post-surgical T1-weighted MRI brain scans were analysed to extract hippocampal and resection volumes, and evaluate post-surgical temporal lobe integrity. Language lateralization indices were derived from functional magnetic resonance imaging. There were no significant pre- to postoperative decrements in memory associated with surgery. In contrast, gains in verbal episodic memory were seen after right temporal lobe surgery, and visual episodic memory improved after left temporal lobe surgery, indicating a functional release in the unoperated temporal lobe after seizure reduction or cessation. Pre- to post-surgical change in memory function was not associated with any indices of brain structure derived from MRI. However, better verbal memory at follow-up was linked to greater post-surgical residual hippocampal volumes, most robustly in left surgical participants. Better semantic memory at follow-up was associated with smaller resection

Atypical modulation of distant functional connectivity by cognitive state in children with Autism Spectrum Disorders

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Xiaozhen eYou

2013-08-01

Full Text Available We examined whether modulation of functional connectivity by cognitive state differed between pre-adolescent children with Autism Spectrum Disorders (ASD and age and IQ-matched control children. Children underwent functional magnetic resonance imaging (fMRI during two states, a resting state followed by a sustained attention task. A voxel-wise method was used to characterize functional connectivity at two levels, local (within a voxel’s 14 mm neighborhood and distant (outside of the voxel’s 14 mm neighborhood to the rest of the brain and regions exhibiting Group X State interaction were identified for both types of connectivity maps. Distant functional connectivity of regions in the left frontal lobe (dorsolateral [BA 11, 10]; supplementary motor area extending into dorsal anterior cingulate [BA 32/8]; and premotor [BA 6, 8, 9], right parietal lobe (paracentral lobule [BA 6 ]; angular gyrus [BA 39/40], and left posterior middle temporal cortex (BA 19/39 showed a Group X State interaction such that relative to the resting state, connectivity reduced (i.e., became focal in control children but increased (i.e., became diffuse in ASD children during the task state. Higher state-related increase in distant connectivity of left frontal and right angular gyrus predicted worse inattention in ASD children. Two graph theory measures (global efficiency and modularity were also sensitive to Group X State differences, with the magnitude of state-related change predicting inattention in the ASD children. Our results indicate that as ASD children transition from an unconstrained to a sustained attentional state, functional connectivity of frontal and parietal regions with the rest of the brain becomes more widespread in a manner that may be maladaptive as it was associated with attention problems in everyday life.

A new approach for improving diagnostic accuracy in Alzheimer's disease and frontal lobe dementia utilising the intrinsic properties of the SPET dataset

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Pagani, Marco; Kovalev, Vassili A.; Lundqvist, Roger; Thurfjell, Lennart; Jacobsson, Hans; Larsson, Stig A.

2003-01-01

Alzheimer's disease (AD) and frontal lobe dementia (FLD) show characteristic patterns of regional cerebral blood flow (rCBF). However, these patterns may overlap with those observed in the aging brain in elderly normal individuals. The aim of this study was to develop a new method for better classification and recognition of AD and FLD cases as compared with normal controls. Forty-six patients with AD, 7 patients with FLD and 34 normal controls (CTR) were included in the study. rCBF was assessed by technetium-99m hexamethylpropylene amine oxime and a three-headed single-photon emission tomography (SPET) camera. A brain atlas was used to define volumes of interest (VOIs) corresponding to the brain lobes. In addition to conventional image processing methods, based on count density/voxel, the new approach also analysed other intrinsic properties of the data by means of gradient computation steps. Hereby, five factors were assessed and tested separately: the mean count density/voxel and its histogram, the mean gradient and its histogram, and the gradient angle co-occurrence matrix. A feature vector concatenating single features was also created and tested. Preliminary feature discrimination was performed using a two-sided t-test and a K-means clustering was then used to classify the image sets into categories. Finally, five-dimensional co-occurrence matrices combining the different intrinsic properties were computed for each VOI, and their ability to recognise the group to which each individual scan belonged was investigated. For correct classification of the AD-CTR groups, the gradient histogram in the parieto-temporal lobes was the most useful single feature (accuracy 91%). FLD and CTR were better classified by the count density/voxel histogram (frontal and occipital lobes) and by the mean gradient (frontal, temporal and parietal lobes, accuracy 98%). For AD and FLD the count density/voxel histogram in the frontal, parietal and occipital lobes classified the groups

Neuropsychological functions and rCBF SPECT in Parkinson's disease patients considered candidates for deep brain stimulation

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Paschali, Anna; Lakiotis, Velissarios; Vassilakos, Paulos; Messinis, Lambros; Lyros, Epameinondas; Papathanasopoulos, Panagiotis; Constantoyannis, Costas; Kefalopoulou, Zinovia

2009-01-01

In the present study, we examined relationships between neuropsychological functions and brain single photon emission computed tomography (SPECT) regional cerebral blood flow (rCBF) observed at presurgical evaluation for deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease (PD) patients. Twenty advanced non-demented PD patients, candidates for DBS surgery, underwent perfusion brain SPECT study and neuropsychological assessment prior to surgery (range: 30-50 days). Patients were further assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) and Hoehn and Yahr (H and Y) scale. During all assessments patients were ''on'' standard medication. NeuroGam software, which permits voxel by voxel analysis, was used to compare the brain perfusion of PD patients with a normal database adjusted for sex and age. Neuropsychological scores were compared to age, education and sex-adjusted normative databases. Our results indicated that the distribution of rCBF showed significant differences when compared to an age- and sex-adjusted normative database. We found impaired blood flow in 17 (85%) of our patients in the left prefrontal lobe, in 14 (70%) in the right prefrontal lobe and in 11 (55%) in the left frontal and right parietal lobes. Neuropsychological testing revealed that 18 (90%) of our patients had significant impairments in measures of executive functions (set-shifting) and 15 (75%) in response inhibition. Furthermore, we found significant correlations between measures of visual attention, executive functions and the right frontal lobe region. The presence of widespread blood flow reduction was observed mainly in the frontal lobes of dementia-free patients with advanced PD. Furthermore, performance on specific cognitive measures was highly related to perfusion brain SPECT findings. (orig.)

Luria’s model of the functional units of the brain and the neuropsychology of dreaming

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Téllez A.

2016-12-01

Full Text Available Traditionally, neuropsychology has focused on identifying the brain mechanisms of specific psychological processes, such as attention, motor skills, perception, memory, language, and consciousness, as well as their corresponding disorders. However, there are psychological processes that have received little attention in this field, such as dreaming. This study examined the clinical and experimental neuropsychological research relevant to dreaming, ranging from sleep disorders in patients with brain damage, to brain functioning during REM sleep, using different methods of brain imaging. These findings were analyzed within the framework of Luria’s Three Functional Unit Model of the Brain, and a proposal was made to explain certain of the essential characteristics of dreaming. This explanation describes how, during dreaming, an activation of the First Functional Unit occurs, comprising the reticular formation of the brainstem; this activates, in turn, the Second Functional Unit — which is formed by the parietal, occipital, and temporal lobes and Unit L, which is comprised of the limbic system, as well as simultaneous hypo-functioning of the Third Functional Unit (frontal lobe. This activity produces a perception of hallucinatory images of various sensory modes, as well as a lack of inhibition, a non-selfreflexive thought process, and a lack of planning and direction of such oneiric images. Dreaming is considered a type of natural confabulation, similar to the one that occurs in patients with frontal lobe damage or schizophrenia. The study also suggests that the confabulatory, bizarre, and impulsive nature of dreaming has a function in the cognitiveemotional homeostasis that aids proper brain function throughout the day.

Temporal Lobe Epilepsy in Children

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Nickels, Katherine C.; Wong-Kisiel, Lily C.; Moseley, Brian D.; Wirrell, Elaine C.

2012-01-01

The temporal lobe is a common focus for epilepsy. Temporal lobe epilepsy in infants and children differs from the relatively homogeneous syndrome seen in adults in several important clinical and pathological ways. Seizure semiology varies by age, and the ictal EEG pattern may be less clear cut than what is seen in adults. Additionally, the occurrence of intractable seizures in the developing brain may impact neurocognitive function remote from the temporal area. While many children will respond favorably to medical therapy, those with focal imaging abnormalities including cortical dysplasia, hippocampal sclerosis, or low-grade tumors are likely to be intractable. Expedient workup and surgical intervention in these medically intractable cases are needed to maximize long-term developmental outcome. PMID:22957247

Nuclear Glycogen Inclusions in Canine Parietal Cells.

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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

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.

Cognitive function and MRI findings in very low birth weight infants

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Imamura, Atsuko; Takagishi, Yuka; Takada, Satoru; Uetani, Yoshiyuki; Nakamura, Toru; Nakamura, Hajime [Kobe Univ. (Japan). School of Medicine; Inagaki, Yuko

1996-07-01

Twenty-two very low birth weight infants at preschool ages of 5-6 years were studied to clarify the correlation between cognitive function and MRI findings. Cognitive function was evaluated by the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Frostig developmental test of visual perception. Ventricular enlargement, assessed by the bioccipital index (B.I.) measured on MRI, was correlated to cognitive disorders. Children with periventricular high intensity areas (T{sub 2}-weighted images) extending from the posterior periventricular region to the parietal lobe tend to highly suffer from cerebral palsy and visuoperceptual impairment. These results indicate that the disorders of cognitive function in very low birth weight infants were caused by a damage of association fibers in periventricular areas which was detectable by MRI. (author)

Unique and shared areas of cognitive function in children with intractable frontal or temporal lobe epilepsy.

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Law, Nicole; Widjaja, Elysa; Smith, Mary Lou

2018-03-01

Previous findings have been mixed in terms of identifying a distinct pattern of neuropsychological deficits in children with frontal lobe epilepsy (FLE) and in those with temporal lobe epilepsy (TLE). The current study investigated the neuropsychological similarities and differences across these two pediatric medically intractable localization-related epilepsies. Thirty-eight children with FLE, 20 children with TLE, and 40 healthy children (HC) participated in this study. A comprehensive battery of standardized tests assessed five neuropsychological domains including intelligence, language, memory, executive function, and motor function. A principal component analysis (PCA) was used to distill our neuropsychological measures into latent components to compare between groups. Principal component analysis extracted 5 latent components: executive function (F1), verbal semantics (F2), motor (F3), nonverbal cognition/impulsivity (F4), and verbal cognition/attention (F5). The group with FLE differed from the HC group on F1, F2, F4, and F5, and had worse performance than the group with TLE on F1; the group with TLE had lower performance relative to the HC group on F2. Our findings suggest that, in comparison with neurotypically developing children, children with medically intractable FLE have more widespread neuropsychological impairments than do children with TLE. The differences between the two patient groups were greatest for the factor score most clearly related to executive function. The results provide mixed support for the concept of specificity in neuropsychological dysfunction among different subtypes of localization-related medically intractable childhood epilepsies. Copyright © 2018 Elsevier Inc. All rights reserved.

Functional MRI of a child with Alice in Wonderland syndrome during an episode of micropsia

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Brumm, Kathleen; Walenski, Matthew; Haist, Frank; Robbins, Shira L.; Granet, David B.; Love, Tracy

2010-01-01

Background Alice in Wonderland syndrome is a perceptual disorder involving brief, transient episodes of visual distortions (metamorphopsia) and can occur in conjunction with certain viral infections. We used functional magnetic resonance imaging to examine visual processing in a 12-year-old boy with viral-onset Alice in Wonderland syndrome during an episode of micropsia (reduction in the perceived size of a form). Methods Functional magnetic resonance imaging was conducted in response to a passive viewing task (reversing checkerboard) and an active viewing task (line-length decisions in the context of the Ponzo illusion). Results In both tasks, the child with Alice in Wonderland syndrome showed reduced activation in primary and extrastriate visual cortical regions but increased activation in parietal lobe cortical regions as compared to a matched control participant. Conclusions The active experience of micropsia in viral-onset Alice in Wonderland syndrome reflects aberrant activity in primary and extrastriate visual cortical regions as well as parietal cortices. The disparate patterns of activity in these regions are discussed in detail. PMID:20598927

Neuronal oscillations form parietal/frontal networks during contour integration.

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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.

Frontal Lobe Seizures

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... cause of frontal lobe epilepsy remains unknown. Complications Status epilepticus. Frontal lobe seizures tend to occur in clusters and may provoke a dangerous condition called status epilepticus — in which seizure activity lasts much longer than ...

The gyri of the octopus vertical lobe have distinct neurochemical identities.

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Shigeno, Shuichi; Ragsdale, Clifton W

2015-06-15

The cephalopod vertical lobe is the largest learning and memory structure known in invertebrate nervous systems. It is part of the visual learning circuit of the central brain, which also includes the superior frontal and subvertical lobes. Despite the well-established functional importance of this system, little is known about neuropil organization of these structures and there is to date no evidence that the five longitudinal gyri of the vertical lobe, perhaps the most distinctive morphological feature of the octopus brain, differ in their connections or molecular identities. We studied the histochemical organization of these structures in hatchling and adult Octopus bimaculoides brains with immunostaining for serotonin, octopus gonadotropin-releasing hormone (oGNRH), and octopressin-neurophysin (OP-NP). Our major finding is that the five lobules forming the vertical lobe gyri have distinct neurochemical signatures. This is most prominent in the hatchling brain, where the median and mediolateral lobules are enriched in OP-NP fibers, the lateral lobule is marked by oGNRH innervation, and serotonin immunostaining heavily labels the median and lateral lobules. A major source of input to the vertical lobe is the superior frontal lobe, which is dominated by a neuropil of interweaving fiber bundles. We have found that this neuropil also has an intrinsic neurochemical organization: it is partitioned into territories alternately enriched or impoverished in oGNRH-containing fascicles. Our findings establish that the constituent lobes of the octopus superior frontal-vertical system have an intricate internal anatomy, one likely to reflect the presence of functional subsystems within cephalopod learning circuitry. © 2015 Wiley Periodicals, Inc.

Astrocyte uncoupling as a cause of human temporal lobe epilepsy.

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Bedner, Peter; Dupper, Alexander; Hüttmann, Kerstin; Müller, Julia; Herde, Michel K; Dublin, Pavel; Deshpande, Tushar; Schramm, Johannes; Häussler, Ute; Haas, Carola A; Henneberger, Christian; Theis, Martin; Steinhäuser, Christian

2015-05-01

Glial cells are now recognized as active communication partners in the central nervous system, and this new perspective has rekindled the question of their role in pathology. In the present study we analysed functional properties of astrocytes in hippocampal specimens from patients with mesial temporal lobe epilepsy without (n = 44) and with sclerosis (n = 75) combining patch clamp recording, K(+) concentration analysis, electroencephalography/video-monitoring, and fate mapping analysis. We found that the hippocampus of patients with mesial temporal lobe epilepsy with sclerosis is completely devoid of bona fide astrocytes and gap junction coupling, whereas coupled astrocytes were abundantly present in non-sclerotic specimens. To decide whether these glial changes represent cause or effect of mesial temporal lobe epilepsy with sclerosis, we developed a mouse model that reproduced key features of human mesial temporal lobe epilepsy with sclerosis. In this model, uncoupling impaired K(+) buffering and temporally preceded apoptotic neuronal death and the generation of spontaneous seizures. Uncoupling was induced through intraperitoneal injection of lipopolysaccharide, prevented in Toll-like receptor4 knockout mice and reproduced in situ through acute cytokine or lipopolysaccharide incubation. Fate mapping confirmed that in the course of mesial temporal lobe epilepsy with sclerosis, astrocytes acquire an atypical functional phenotype and lose coupling. These data suggest that astrocyte dysfunction might be a prime cause of mesial temporal lobe epilepsy with sclerosis and identify novel targets for anti-epileptogenic therapeutic intervention. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Motor imagery training: Kinesthetic imagery strategy and inferior parietal fMRI activation.

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Lebon, Florent; Horn, Ulrike; Domin, Martin; Lotze, Martin

2018-04-01

Motor imagery (MI) is the mental simulation of action frequently used by professionals in different fields. However, with respect to performance, well-controlled functional imaging studies on MI training are sparse. We investigated changes in fMRI representation going along with performance changes of a finger sequence (error and velocity) after MI training in 48 healthy young volunteers. Before training, we tested the vividness of kinesthetic and visual imagery. During tests, participants were instructed to move or to imagine moving the fingers of the right hand in a specific order. During MI training, participants repeatedly imagined the sequence for 15 min. Imaging analysis was performed using a full-factorial design to assess brain changes due to imagery training. We also used regression analyses to identify those who profited from training (performance outcome and gain) with initial imagery scores (vividness) and fMRI activation magnitude during MI at pre-test (MI pre ). After training, error rate decreased and velocity increased. We combined both parameters into a common performance index. FMRI activation in the left inferior parietal lobe (IPL) was associated with MI and increased over time. In addition, fMRI activation in the right IPL during MI pre was associated with high initial kinesthetic vividness. High kinesthetic imagery vividness predicted a high performance after training. In contrast, occipital activation, associated with visual imagery strategies, showed a negative predictive value for performance. Our data echo the importance of high kinesthetic vividness for MI training outcome and consider IPL as a key area during MI and through MI training. © 2018 Wiley Periodicals, Inc.

Thalamotemporal impairment in temporal lobe epilepsy: a combined MRI analysis of structure, integrity, and connectivity.

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Keller, Simon S; O'Muircheartaigh, Jonathan; Traynor, Catherine; Towgood, Karren; Barker, Gareth J; Richardson, Mark P

2014-02-01

Thalamic abnormality in temporal lobe epilepsy (TLE) is well known from imaging studies, but evidence is lacking regarding connectivity profiles of the thalamus and their involvement in the disease process. We used a novel multisequence magnetic resonance imaging (MRI) protocol to elucidate the relationship between mesial temporal and thalamic pathology in TLE. For 23 patients with TLE and 23 healthy controls, we performed T1 -weighted (for analysis of tissue structure), diffusion tensor imaging (tissue connectivity), and T1 and T2 relaxation (tissue integrity) MRI across the whole brain. We used connectivity-based segmentation to determine connectivity patterns of thalamus to ipsilateral cortical regions (occipital, parietal, prefrontal, postcentral, precentral, and temporal). We subsequently determined volumes, mean tractography streamlines, and mean T1 and T2 relaxometry values for each thalamic segment preferentially connecting to a given cortical region, and of the hippocampus and entorhinal cortex. As expected, patients had significant volume reduction and increased T2 relaxation time in ipsilateral hippocampus and entorhinal cortex. There was bilateral volume loss, mean streamline reduction, and T2 increase of the thalamic segment preferentially connected to temporal lobe, corresponding to anterior, dorsomedial, and pulvinar thalamic regions, with no evidence of significant change in any other thalamic segments. Left and right thalamotemporal segment volume and T2 were significantly correlated with volume and T2 of ipsilateral (epileptogenic), but not contralateral (nonepileptogenic), mesial temporal structures. These convergent and robust data indicate that thalamic abnormality in TLE is restricted to the area of the thalamus that is preferentially connected to the epileptogenic temporal lobe. The degree of thalamic pathology is related to the extent of mesial temporal lobe damage in TLE. © 2014 The Authors. Epilepsia published by Wiley Periodicals, Inc

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

Giant lipoma arising from deep lobe of the parotid gland

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Hsu Ying-Che

2006-06-01

Full Text Available Abstract Background Lipomas are common benign soft tissue neoplasms but they are found very rarely in the deep lobe of parotid gland. Surgical intervention in these tumors is challenging because of the proximity of the facial nerve, and thus knowledge of the anatomy and meticulous surgical technique are essential. Case presentation A 71-year-old female presented with a large asymptomatic mass, which had occupied the left facial area for over the past fifteen years, and she requested surgical excision for a cosmetically better facial appearance. The computed tomography (CT scan showed a well-defined giant lipoma arising from the left deep parotid gland. The lipoma was successfully enucleated after full exposure and mobilization of the overlying facial nerve branches. The surgical specimen measured 9 × 6 cm in size, and histopathology revealed fibrolipoma. The patient experienced an uneventful recovery, with a satisfying facial contour and intact facial nerve function. Conclusion Giant lipomas involving the deep parotid lobe are extremely rare. The high-resolution CT scan provides an accurate and cost-effective preoperative investigative method. Surgical management of deep lobe lipoma should be performed by experienced surgeons due to the need for meticulous dissection of the facial nerve branches. Superficial parotidectomy before deep lobe lipoma removal may be unnecessary in selected cases because preservation of the superficial lobe may contribute to a better aesthetic and functional result.

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

The neurobiology of cognitive disorders in temporal lobe epilepsy

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Bell, Brian; Lin, Jack J.; Seidenberg, Michael; Hermann, Bruce

2013-01-01

Cognitive impairment and especially memory disruption is a major complicating feature of the epilepsies. In this review we begin with a focus on the problem of memory impairment in temporal lobe epilepsy. We start with a brief overview of the early development of knowledge regarding the anatomic substrates of memory disorder in temporal lobe epilepsy, followed by discussion of the refinement of that knowledge over time as informed by the outcomes of epilepsy surgery (anterior temporal lobectomy) and the clinical efforts to predict those patients at greatest risk of adverse cognitive outcomes following epilepsy surgery. These efforts also yielded new theoretical insights regarding the function of the human hippocampus and a few examples of these insights are touched on briefly. Finally, the vastly changing view of temporal lobe epilepsy is examined including findings demonstrating that anatomic abnormalities extend far outside the temporal lobe, cognitive impairments extend beyond memory function, with linkage of these distributed cognitive and anatomic abnormalities pointing to a new understanding of the anatomic architecture of cognitive impairment in epilepsy. Challenges remain in understanding the origin of these cognitive and anatomic abnormalities, their progression over time, and most importantly, how to intervene to protect cognitive and brain health in epilepsy. PMID:21304484

Functional imaging of semantic memory predicts postoperative episodic memory functions in chronic temporal lobe epilepsy.

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Köylü, Bülent; Walser, Gerald; Ischebeck, Anja; Ortler, Martin; Benke, Thomas

2008-08-05

Medial temporal (MTL) structures have crucial functions in episodic (EM), but also in semantic memory (SM) processing. Preoperative functional magnetic resonance imaging (fMRI) activity within the MTL is increasingly used to predict post-surgical memory capacities. Based on the hypothesis that EM and SM memory functions are both hosted by the MTL the present study wanted to explore the relationship between SM related activations in the MTL as assessed before and the capacity of EM functions after surgery. Patients with chronic unilateral left (n=14) and right (n=12) temporal lobe epilepsy (TLE) performed a standard word list learning test pre- and postoperatively, and a fMRI procedure before the operation using a semantic decision task. SM processing caused significant bilateral MTL activations in both patient groups. While right TLE patients showed asymmetry of fMRI activation with more activation in the left MTL, left TLE patients had almost equal activation in both MTL regions. Contrasting left TLE versus right TLE patients revealed greater activity within the right MTL, whereas no significant difference was observed for the reverse contrast. Greater effect size in the MTL region ipsilateral to the seizure focus was significantly and positively correlated with preoperative EM abilities. Greater effect size in the contralateral MTL was correlated with better postoperative verbal EM, especially in left TLE patients. These results suggest that functional imaging of SM tasks may be useful to predict postoperative verbal memory in TLE. They also advocate a common neuroanatomical basis for SM and EM processes in the MTL.

A new approach for improving diagnostic accuracy in Alzheimer's disease and frontal lobe dementia utilising the intrinsic properties of the SPET dataset

Energy Technology Data Exchange (ETDEWEB)

Pagani, Marco [Institute of Cognitive Sciences and Technology, CNR, Viale Marx 15, 00137, Rome (Italy); Section of Nuclear Medicine, Karolinska Hospital/Institute, Stockholm (Sweden); Kovalev, Vassili A. [Institute of Engineering Cybernetics, Belarus National Academy of Sciences, Minsk (Belarus); Max-Planck Institute of Cognitive Neuroscience, Leipzig (Germany); Lundqvist, Roger; Thurfjell, Lennart [Applied Medical Imaging, Uppsala (Sweden); Jacobsson, Hans [Section of Nuclear Medicine, Karolinska Hospital/Institute, Stockholm (Sweden); Department of Radiology, Karolinska Hospital, Stockholm (Sweden); Larsson, Stig A. [Section of Nuclear Medicine, Karolinska Hospital/Institute, Stockholm (Sweden)

2003-11-01

Alzheimer's disease (AD) and frontal lobe dementia (FLD) show characteristic patterns of regional cerebral blood flow (rCBF). However, these patterns may overlap with those observed in the aging brain in elderly normal individuals. The aim of this study was to develop a new method for better classification and recognition of AD and FLD cases as compared with normal controls. Forty-six patients with AD, 7 patients with FLD and 34 normal controls (CTR) were included in the study. rCBF was assessed by technetium-99m hexamethylpropylene amine oxime and a three-headed single-photon emission tomography (SPET) camera. A brain atlas was used to define volumes of interest (VOIs) corresponding to the brain lobes. In addition to conventional image processing methods, based on count density/voxel, the new approach also analysed other intrinsic properties of the data by means of gradient computation steps. Hereby, five factors were assessed and tested separately: the mean count density/voxel and its histogram, the mean gradient and its histogram, and the gradient angle co-occurrence matrix. A feature vector concatenating single features was also created and tested. Preliminary feature discrimination was performed using a two-sided t-test and a K-means clustering was then used to classify the image sets into categories. Finally, five-dimensional co-occurrence matrices combining the different intrinsic properties were computed for each VOI, and their ability to recognise the group to which each individual scan belonged was investigated. For correct classification of the AD-CTR groups, the gradient histogram in the parieto-temporal lobes was the most useful single feature (accuracy 91%). FLD and CTR were better classified by the count density/voxel histogram (frontal and occipital lobes) and by the mean gradient (frontal, temporal and parietal lobes, accuracy 98%). For AD and FLD the count density/voxel histogram in the frontal, parietal and occipital lobes classified the

Neural Mechanism of Cognitive Control Impairment in Patients with Hepatic Cirrhosis: A Functional Magnetic Resonance Imaging Study

Energy Technology Data Exchange (ETDEWEB)

Long Jiang Zhang; Guifen Yang; Jianzhong Yin; Yawu Liu; Ji Qi [Dept. of Radiology, Tianjin First Central Hospital of Tianjin Medical Univ, Tianjin (China)

2007-07-15

Background: Many studies have claimed the existence of attention alterations in cirrhotic patients without overt hepatic encephalopathy (HE). No functional magnetic resonance imaging (fMRI) study in this respect has been published. Purpose: To investigate the neural basis of cognitive control deficiency in cirrhotic patients using fMRI. Material and Methods: 14 patients with hepatic cirrhosis and 14 healthy volunteers were included in the study. A modified Stroop task with Chinese characters was used as the target stimulus, and block-design fMRI was used to acquire resource data, including four stimulus blocks and five control blocks, each presented alternatively. Image analysis was performed using statistical parametric mapping 99. After fMRI examinations were complete, behavior tests of Stroop interference were performed for all subjects. Overall reaction time and error numbers were recorded. Results: Both healthy volunteers and patients with hepatic cirrhosis had Stroop interference effects. Patients with hepatic cirrhosis had more errors and longer reaction time in performing an incongruous color-naming task than healthy volunteers (P<0.001); there was no significant difference in performing an incongruous word-reading task (P 0.066). Compared with controls, patients with hepatic cirrhosis had greater activation of the bilateral prefrontal cortex and parietal cortex when performing the incongruous word-reading task. With increased conflict, activation of the anterior cingulate cortex (ACC), bilateral prefrontal cortex (PFC), parietal lobe, and temporal fusiform gyrus (TFG) was decreased when patients with hepatic cirrhosis performed the incongruous color-naming task. Conclusion: This study demonstrates that patients with hepatic cirrhostic have cognitive control deficiency. The abnormal brain network of the ACC-PFC-parietal lobe-TFG is the neural basis of cognitive control impairment in cirrhotic patients.

Neural Mechanism of Cognitive Control Impairment in Patients with Hepatic Cirrhosis: A Functional Magnetic Resonance Imaging Study

International Nuclear Information System (INIS)

Long Jiang Zhang; Guifen Yang; Jianzhong Yin; Yawu Liu; Ji Qi

2007-01-01

Background: Many studies have claimed the existence of attention alterations in cirrhotic patients without overt hepatic encephalopathy (HE). No functional magnetic resonance imaging (fMRI) study in this respect has been published. Purpose: To investigate the neural basis of cognitive control deficiency in cirrhotic patients using fMRI. Material and Methods: 14 patients with hepatic cirrhosis and 14 healthy volunteers were included in the study. A modified Stroop task with Chinese characters was used as the target stimulus, and block-design fMRI was used to acquire resource data, including four stimulus blocks and five control blocks, each presented alternatively. Image analysis was performed using statistical parametric mapping 99. After fMRI examinations were complete, behavior tests of Stroop interference were performed for all subjects. Overall reaction time and error numbers were recorded. Results: Both healthy volunteers and patients with hepatic cirrhosis had Stroop interference effects. Patients with hepatic cirrhosis had more errors and longer reaction time in performing an incongruous color-naming task than healthy volunteers (P<0.001); there was no significant difference in performing an incongruous word-reading task (P 0.066). Compared with controls, patients with hepatic cirrhosis had greater activation of the bilateral prefrontal cortex and parietal cortex when performing the incongruous word-reading task. With increased conflict, activation of the anterior cingulate cortex (ACC), bilateral prefrontal cortex (PFC), parietal lobe, and temporal fusiform gyrus (TFG) was decreased when patients with hepatic cirrhosis performed the incongruous color-naming task. Conclusion: This study demonstrates that patients with hepatic cirrhostic have cognitive control deficiency. The abnormal brain network of the ACC-PFC-parietal lobe-TFG is the neural basis of cognitive control impairment in cirrhotic patients

Perfusion deficits and functional connectivity alterations in patients with post-traumatic stress disorder

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Liu, Yang; Li, Baojuan; Zhang, Xi; Zhang, Linchuan; Li, Liang; Lu, Hongbing

2016-03-01

To explore the alteration in cerebral blood flow (CBF) and functional connectivity between survivors with recent onset post-traumatic stress disorder (PTSD) and without PTSD, survived from the same coal mine flood disaster. In this study, a processing pipeline using arterial spin labeling (ASL) sequence was proposed. Considering low spatial resolution of ASL sequence, a linear regression method was firstly used to correct the partial volume (PV) effect for better CBF estimation. Then the alterations of CBF between two groups were analyzed using both uncorrected and PV-corrected CBF maps. Based on altered CBF regions detected from the CBF analysis as seed regions, the functional connectivity abnormities in PTSD patients was investigated. The CBF analysis using PV-corrected maps indicates CBF deficits in the bilateral frontal lobe, right superior frontal gyrus and right corpus callosum of PTSD patients, while only right corpus callosum was identified in uncorrected CBF analysis. Furthermore, the regional CBF of the right superior frontal gyrus exhibits significantly negative correlation with the symptom severity in PTSD patients. The resting-state functional connectivity indicates increased connectivity between left frontal lobe and right parietal lobe. These results indicate that PV-corrected CBF exhibits more subtle perfusion changes and may benefit further perfusion and connectivity analysis. The symptom-specific perfusion deficits and aberrant connectivity in above memory-related regions may be putative biomarkers for recent onset PTSD induced by a single prolonged trauma exposure and help predict the severity of PTSD.

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

DEFF Research Database (Denmark)

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...

Exploring the psychosis functional connectome: aberrant intrinsic networks in schizophrenia and bipolar disorder

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Vince D Calhoun

2012-01-01

Full Text Available Intrinsic functional brain networks (INs are regions showing temporal coherence with one another. These INs are present in the context of a task (as opposed to an undirected task such as rest, albeit modulated to a degree both spatially and temporally. Prominent networks include the default mode, attentional fronto-parietal, executive control, bilateral temporal lobe and motor networks. The characterization of INs has recently gained considerable momentum, however; most previous studies evaluate only a small subset of the intrinsic networks (e.g. default mode. In this paper we use independent component analysis to study INs decomposed from fMRI data collected in a large group of schizophrenia patients, healthy controls, and individuals with bipolar disorder, while performing an auditory oddball task. Schizophrenia and bipolar disorder share significant overlap in clinical symptoms, brain characteristics, and risk genes which motivates our goal of identifying whether functional imaging data can differentiate the two disorders. We tested for group differences in properties of all identified intrinsic networks including spatial maps, spectra, and functional network connectivity. A small set of default mode, temporal lobe, and frontal networks with default mode regions appearing to play a key role in all comparisons. Bipolar subjects showed more prominent changes in ventromedial and prefrontal default mode regions whereas schizophrenia patients showed changes in posterior default mode regions. Anti-correlations between left parietal areas and dorsolateral prefrontal cortical areas were different in bipolar and schizophrenia patients and amplitude was significantly different from healthy controls in both patient groups. Patients exhibited similar frequency behavior across multiple networks with decreased low frequency power. In summary, a comprehensive analysis of intrinsic networks reveals a key role for the default mode in both schizophrenia and

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

Age differences in intercorrelations between regional cerebral metabolic rates for glucose

International Nuclear Information System (INIS)

Horwitz, B.; Duara, R.; Rapoport, S.I.

1986-01-01

Patterns of cerebral metabolic intercorrelations were compared in the resting state in 15 healthy young men (ages 20 to 32 years) and 15 healthy elderly men (ages 64 to 83 years). Controlling for whole-brain glucose metabolism, partial correlation coefficients were determined between pairs of regional cerebral metabolic rates for glucose determined by positron emission tomography using [18F]fluorodeoxyglucose and obtained in 59 brain regions. Compared with the young men, the elderly men had fewer statistically significant correlations, with the most notable reductions observed between the parietal lobe regions, and between the parietal and frontal lobe regions. These results suggest that cerebral functional interactions are reduced in healthy elderly men

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.

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.

Intranasal trigeminal function in subjects with and without an intact sense of smell.

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Iannilli, E; Gerber, J; Frasnelli, J; Hummel, T

2007-03-30

The intranasal trigeminal system is involved in the perception of odors. To investigate the cerebral processing of sensory information from the trigeminal nerve in detail we studied subjects with and without olfactory function using functional magnetic resonance imaging. A normosmic group (n=12) was compared with a group of anosmic subjects (n=11). For trigeminal stimulation gaseous CO(2) was used. Following right-sided stimulation with CO(2) controls exhibited a stronger right-sided cerebral activation than anosmic subjects. Stronger activation was found in controls compared to anosmic subjects for the right prefrontal cortex, the right somatosensory cortex (SI), and the left parietal insula. In contrast, relatively higher activation was found in anosmic subjects for the left supplementary motor area in the frontal lobe, the right superior and middle temporal lobe, the left parahippocampal gyrus in the limbic lobe, and the sub-lobar region of the left putamen and right insula which was mostly due to a decreased BOLD signal of controls in these areas. Additional conjunction analysis revealed that activated areas common to the two groups were the cerebellum and the right premotor frontal cortex. These data suggest that the processing of the trigeminally mediated information is different in the presence or absence of an intact sense of smell, pointing towards the intimate connection between the two chemosensory systems.

Are personality traits of juvenile myoclonic epilepsy related to frontal lobe dysfunctions? A proton MRS study.

Science.gov (United States)

de Araújo Filho, Gerardo Maria; Lin, Katia; Lin, Jaime; Peruchi, Mirella M; Caboclo, Luís Otávio S F; Guaranha, Mirian S B; Guilhoto, Laura M F F; Carrete, Henrique; Yacubian, Elza Márcia T

2009-05-01

Personality traits characterized by emotional instability and immaturity, unsteadiness, lack of discipline, hedonism, frequent and rapid mood changes, and indifference toward one's disease have been associated with patients who have juvenile myoclonic epilepsy (JME). Literature data demonstrate worse seizure control and more psychosocial dysfunctions among patients with JME who have those traits. In this controlled study we performed a correlation analysis of psychiatric scores with magnetic resonance spectroscopy (MRS) values across JME patients, aiming to verify the existence of a possible relation between frontal lobe dysfunction and the prevalence of personality disorders (PDs) in JME. Sixteen JME patients with cluster B PDs, 41 JME patients without any psychiatric disorder, and 30 healthy controls were submitted to a psychiatric evaluation and to a quantitative multivoxel MRS of thalamus; insula; cingulate gyrus; striatum; and frontal, parietal, and occipital lobes. Groups were homogeneous according to age, gender, and manual dominance. Psychiatric evaluation was performed through the Scheduled Clinical Interview for DSM-IV, Axis I and II (SCID I and II, respectively). A significant reduction of N-acetyl-aspartate over creatinine (NAA/Cr) ratio was observed mainly in the left frontal lobe in the JME and PD group. In addition, a significant increase in the glutamate-glutamine over creatinine GLX/Cr ratio was also observed in this referred region in the same group. These data support the hypothesis that PDs in JME could represent neuronal dysfunction and possibly a more severe form of this epileptic syndrome.

Declarative long-term memory and the mesial temporal lobe: Insights from a 5-year postsurgery follow-up study on refractory temporal lobe epilepsy.

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Salvato, Gerardo; Scarpa, Pina; Francione, Stefano; Mai, Roberto; Tassi, Laura; Scarano, Elisa; Lo Russo, Giorgio; Bottini, Gabriella

2016-11-01

It is largely recognized that the mesial temporal lobe and its substructure support declarative long-term memory (LTM). So far, different theories have been suggested, and the organization of declarative verbal LTM in the brain is still a matter of debate. In the current study, we retrospectively selected 151 right-handed patients with temporal lobe epilepsy with and without hippocampal sclerosis, with a homogeneous (seizure-free) clinical outcome. We analyzed verbal memory performance within a normalized scores context, by means of prose recall and word paired-associate learning tasks. Patients were tested at presurgical baseline, 6months, 2 and 5years after anteromesial temporal lobe surgery, using parallel versions of the neuropsychological tests. Our main finding revealed a key involvement of the left temporal lobe and, in particular, of the left hippocampus in prose recall rather than word paired-associate task. We also confirmed that shorter duration of epilepsy, younger age, and withdrawal of antiepileptic drugs would predict a better memory outcome. When individual memory performance was taken into account, data showed that females affected by left temporal lobe epilepsy for longer duration were more at risk of presenting a clinically pathologic LTM at 5years after surgery. Taken together, these findings shed new light on verbal declarative memory in the mesial temporal lobe and on the behavioral signature of the functional reorganization after the surgical treatment of temporal lobe epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.

Working Memory, Long-Term Memory, and Medial Temporal Lobe Function

Science.gov (United States)

Jeneson, Annette; Squire, Larry R.

2012-01-01

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance…

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

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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.

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.

White Matter Tracts Connected to the Medial Temporal Lobe Support the Development of Mnemonic Control.

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Wendelken, Carter; Lee, Joshua K; Pospisil, Jacqueline; Sastre, Marcos; Ross, Julia M; Bunge, Silvia A; Ghetti, Simona

2015-09-01

One of the most important factors driving the development of memory during childhood is mnemonic control, or the capacity to initiate and maintain the processes that guide encoding and retrieval operations. The ability to selectively attend to and encode relevant stimuli is a particularly useful form of mnemonic control, and is one that undergoes marked improvement over childhood. We hypothesized that structural integrity of white matter tracts, in particular those connecting medial temporal lobe memory regions to other cortical areas, and/or those connecting frontal and parietal control regions, should contribute to successful mnemonic control. To test this hypothesis, we examined the relationship between structural integrity of selected white matter tracts and an experimental measure of mnemonic control, involving enhancement of memory by attention at encoding, in 116 children aged 7-11 and 25 young adults. We observed a positive relationship between integrity of uncinate fasciculus and mnemonic enhancement across age groups. In adults, but not in children, we also observed an association between mnemonic enhancement and integrity of ventral cingulum bundle and ventral fornix/fimbria. Integrity of fronto-parietal tracts, including dorsal cingulum and superior longitudinal fasciculus, was unrelated to mnemonic enhancement. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Autobiographical Memory Retrieval and Hippocampal Activation as a Function of Repetition and the Passage of Time

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Lynn Nadel

2007-01-01

Full Text Available Multiple trace theory (MTT predicts that hippocampal memory traces expand and strengthen as a function of repeated memory retrievals. We tested this hypothesis utilizing fMRI, comparing the effect of memory retrieval versus the mere passage of time on hippocampal activation. While undergoing fMRI scanning, participants retrieved remote autobiographical memories that had been previously retrieved either one month earlier, two days earlier, or multiple times during the preceding month. Behavioral analyses revealed that the number and consistency of memory details retrieved increased with multiple retrievals but not with the passage of time. While all three retrieval conditions activated a similar set of brain regions normally associated with autobiographical memory retrieval including medial temporal lobe structures, hippocampal activation did not change as a function of either multiple retrievals or the passage of time. However, activation in other brain regions, including the precuneus, lateral prefrontal cortex, parietal cortex, lateral temporal lobe, and perirhinal cortex increased after multiple retrievals, but was not influenced by the passage of time. These results have important implications for existing theories of long-term memory consolidation.

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.

The Classical Pathways of Occipital Lobe Epileptic Propagation Revised in the Light of White Matter Dissection.

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Latini, Francesco; Hjortberg, Mats; Aldskogius, Håkan; Ryttlefors, Mats

2015-01-01

The clinical evidences of variable epileptic propagation in occipital lobe epilepsy (OLE) have been demonstrated by several studies. However the exact localization of the epileptic focus sometimes represents a problem because of the rapid propagation to frontal, parietal, or temporal regions. Each white matter pathway close to the supposed initial focus can lead the propagation towards a specific direction, explaining the variable semiology of these rare epilepsy syndromes. Some new insights in occipital white matter anatomy are herein described by means of white matter dissection and compared to the classical epileptic patterns, mostly based on the central position of the primary visual cortex. The dissections showed a complex white matter architecture composed by vertical and longitudinal bundles, which are closely interconnected and segregated and are able to support specific high order functions with parallel bidirectional propagation of the electric signal. The same sublobar lesions may hyperactivate different white matter bundles reemphasizing the importance of the ictal semiology as a specific clinical demonstration of the subcortical networks recruited. Merging semiology, white matter anatomy, and electrophysiology may lead us to a better understanding of these complex syndromes and tailored therapeutic options based on individual white matter connectivity.

The Classical Pathways of Occipital Lobe Epileptic Propagation Revised in the Light of White Matter Dissection

Science.gov (United States)

Latini, Francesco; Hjortberg, Mats; Aldskogius, Håkan; Ryttlefors, Mats

2015-01-01

The clinical evidences of variable epileptic propagation in occipital lobe epilepsy (OLE) have been demonstrated by several studies. However the exact localization of the epileptic focus sometimes represents a problem because of the rapid propagation to frontal, parietal, or temporal regions. Each white matter pathway close to the supposed initial focus can lead the propagation towards a specific direction, explaining the variable semiology of these rare epilepsy syndromes. Some new insights in occipital white matter anatomy are herein described by means of white matter dissection and compared to the classical epileptic patterns, mostly based on the central position of the primary visual cortex. The dissections showed a complex white matter architecture composed by vertical and longitudinal bundles, which are closely interconnected and segregated and are able to support specific high order functions with parallel bidirectional propagation of the electric signal. The same sublobar lesions may hyperactivate different white matter bundles reemphasizing the importance of the ictal semiology as a specific clinical demonstration of the subcortical networks recruited. Merging semiology, white matter anatomy, and electrophysiology may lead us to a better understanding of these complex syndromes and tailored therapeutic options based on individual white matter connectivity. PMID:26063964

Percent wall thickness evaluated by Gd-DTPA enhanced cine MRI as an indicator of local parietal movement in hypertrophic cardiomyopathy

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Hirano, Masaharu

1998-01-01

Hypertrophic cardiomyopathy (HCM) is a cardiac disease, the basic pathology of which consists of a decrease in left ventricular dilation compliance due to uneven hypertrophy of the left ventricular wall. Magnetic resonance imaging (MRI) is useful in monitoring uneven parietal hypertrophy and kinetics in HCM patients. The present study was undertaken in 47 HCM patients who showed asymmetrical septal hypertrophy to determine if percent thickness can be an indicator of left ventricular local movement using cine MRI. Longest and shortest axis images were acquired by the ECG synchronization method using a 1.5 T MR imager. Cardiac function was analyzed based on longest axis cine images, and telediastolic and telesystolic parietal thickness were measured based on shorter axis cine images at the papillary muscle level. Parietal movement index and percent thickness were used as indicators of local parietal movement. The correlation between these indicators and parietal thickness was evaluated. The percent thickness changed at an earlier stage of hypertrophy than the parietal movement index, thus it is thought to be useful in detecting left ventricular parietal movement disorders at an early stage of HCM. (author)

Percent wall thickness evaluated by Gd-DTPA enhanced cine MRI as an indicator of local parietal movement in hypertrophic cardiomyopathy

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Hirano, Masaharu [Tokyo Medical Coll. (Japan)

1998-11-01

Hypertrophic cardiomyopathy (HCM) is a cardiac disease, the basic pathology of which consists of a decrease in left ventricular dilation compliance due to uneven hypertrophy of the left ventricular wall. Magnetic resonance imaging (MRI) is useful in monitoring uneven parietal hypertrophy and kinetics in HCM patients. The present study was undertaken in 47 HCM patients who showed asymmetrical septal hypertrophy to determine if percent thickness can be an indicator of left ventricular local movement using cine MRI. Longest and shortest axis images were acquired by the ECG synchronization method using a 1.5 T MR imager. Cardiac function was analyzed based on longest axis cine images, and telediastolic and telesystolic parietal thickness were measured based on shorter axis cine images at the papillary muscle level. Parietal movement index and percent thickness were used as indicators of local parietal movement. The correlation between these indicators and parietal thickness was evaluated. The percent thickness changed at an earlier stage of hypertrophy than the parietal movement index, thus it is thought to be useful in detecting left ventricular parietal movement disorders at an early stage of HCM. (author)

Temporal lobe sclerosis associated with hippocampal sclerosis in temporal lobe epilepsy: neuropathological features.

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Thom, Maria; Eriksson, Sofia; Martinian, Lillian; Caboclo, Luis O; McEvoy, Andrew W; Duncan, John S; Sisodiya, Sanjay M

2009-08-01

Widespread changes involving neocortical and mesial temporal lobe structures can be present in patients with temporal lobe epilepsy and hippocampal sclerosis. The incidence, pathology, and clinical significance of neocortical temporal lobe sclerosis (TLS) are not well characterized. We identified TLS in 30 of 272 surgically treated cases of hippocampal sclerosis. Temporal lobe sclerosis was defined by variable reduction of neurons from cortical layers II/III and laminar gliosis; it was typically accompanied by additional architectural abnormalities of layer II, that is, abnormal neuronal orientation and aggregation. Quantitative analysis including tessellation methods for the distribution of layer II neurons supported these observations. In 40% of cases, there was a gradient of TLS with more severe involvement toward the temporal pole, possibly signifying involvement of hippocampal projection pathways. There was a history of a febrile seizure as an initial precipitating injury in 73% of patients with TLS compared with 36% without TLS; no other clinical differences between TLS and non-TLS cases were identified. Temporal lobe sclerosis was not evident preoperatively by neuroimaging. No obvious effect of TLS on seizure outcome was noted after temporal lobe resection; 73% became seizure-free at 2-year follow-up. In conclusion, approximately 11% of surgically treated hippocampal sclerosis is accompanied by TLS. Temporal lobe sclerosis is likely an acquired process with accompanying reorganizational dysplasia and an extension of mesial temporal sclerosis rather than a separate pathological entity.

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

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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.

Activation on occipital lobe in children with abacus mental calculation training: an fMRI study

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

2011-01-01

Objective: By exploring the activation on occipital lobe in children with and without abacus mental calculation training when they engaged in different calculation tasks with functional magnetic resonance imaging (fMRI), to identify the possible mechanism of occipital lobe in abacus mental calculation. Methods: fMRI was performed in children trained with and without (sixteen in each group) abacus mental calculation when they engaged in addition, subtraction. multiplication, division, and number-object control judging tasks. The data processing and statistical analysis were performed on SPM 2.0 (statistical parametric mapping 2.0) and the related-brain functional areas were identified. The activation on occipital lobe was observed carefully. The difference in activated areas of occipital lobe was statistically significant between two groups engaged in different tasks of calculations (P<0.01). Result: Bilateral occipital lobe, especially in the cuneus and lingual gyrus, were activated in children trained with abacus mental calculation. The main activated area was lingual gyrus in children without abacus mental calculation. Conclusion: The occipital lobe participates visuospatial processing in the abacus mental calculations. The neuromechanism maybe account for the specific activation in occipital lobe. (authors)

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.

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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.

Neuropsychological functions and rCBF SPECT in Parkinson's disease patients considered candidates for deep brain stimulation

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Paschali, Anna; Lakiotis, Velissarios; Vassilakos, Paulos [University of Patras Medical School, Department of Nuclear Medicine, Patras (Greece); Messinis, Lambros; Lyros, Epameinondas; Papathanasopoulos, Panagiotis [University of Patras Medical School, Department of Neurology, Neuropsychology Section, Patras (Greece); Constantoyannis, Costas; Kefalopoulou, Zinovia [University of Patras Medical School, Department of Neurosurgery, Patras (Greece)

2009-11-15

In the present study, we examined relationships between neuropsychological functions and brain single photon emission computed tomography (SPECT) regional cerebral blood flow (rCBF) observed at presurgical evaluation for deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease (PD) patients. Twenty advanced non-demented PD patients, candidates for DBS surgery, underwent perfusion brain SPECT study and neuropsychological assessment prior to surgery (range: 30-50 days). Patients were further assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) and Hoehn and Yahr (H and Y) scale. During all assessments patients were ''on'' standard medication. NeuroGam software, which permits voxel by voxel analysis, was used to compare the brain perfusion of PD patients with a normal database adjusted for sex and age. Neuropsychological scores were compared to age, education and sex-adjusted normative databases. Our results indicated that the distribution of rCBF showed significant differences when compared to an age- and sex-adjusted normative database. We found impaired blood flow in 17 (85%) of our patients in the left prefrontal lobe, in 14 (70%) in the right prefrontal lobe and in 11 (55%) in the left frontal and right parietal lobes. Neuropsychological testing revealed that 18 (90%) of our patients had significant impairments in measures of executive functions (set-shifting) and 15 (75%) in response inhibition. Furthermore, we found significant correlations between measures of visual attention, executive functions and the right frontal lobe region. The presence of widespread blood flow reduction was observed mainly in the frontal lobes of dementia-free patients with advanced PD. Furthermore, performance on specific cognitive measures was highly related to perfusion brain SPECT findings. (orig.)

99mTc-HMPAO SPECT in dementia of the Alzheimer type. Hypoperfusion in the medial temporal region

International Nuclear Information System (INIS)

Nakamura, Yu; Kawakatsu, Shinobu; Shinohara, Masao; Nadaoka, Toshihide; Totsuka, Shiro; Komatani, Akio

1995-01-01

This study examined regional cerebral blood flow (rCBF) by single photon emission computed tomography (SPECT) using technetium 99m-hexamethyl-propyleneamineoxime and correlated the results with neuropsychological findings in 30 patients with dementia of the Alzheimer type (AT dementia). Ten healthy persons served as controls. The group of mild AT dementia exhibited a significant decrease in rCBF in the lower part of the right lateral frontal lobe and in the right parietal lobe. In the group of moderate AT dementia, the significant decrease in rCBF was noted in the lower part of the bilateral frontal lobes, the parietal part of the temporal lobe, the parietal lobe, and the medial temporal lobe. Factor analysis for neuropsychological test revealed three factors involved in rCBF. There was a significantly positive correlation between the factor responsible for memory and recall and rCBF in the left frontal lobe, the anterior part of the lateral temporal lobe, and the medial temporal lobe. These findings suggested that disturbance of the memory circuit may exist in the medial temporal lobe and others as pathophysiology of AT dementia. (N.K.)

The iconography of mourning and its neural correlates: a functional neuroimaging study.

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Labek, Karin; Berger, Samantha; Buchheim, Anna; Bosch, Julia; Spohrs, Jennifer; Dommes, Lisa; Beschoner, Petra; Stingl, Julia C; Viviani, Roberto

2017-08-01

The present functional neuroimaging study focuses on the iconography of mourning. A culture-specific pattern of body postures of mourning individuals, mostly suggesting withdrawal, emerged from a survey of visual material. When used in different combinations in stylized drawings in our neuroimaging study, this material activated cortical areas commonly seen in studies of social cognition (temporo-parietal junction, superior temporal gyrus, and inferior temporal lobe), empathy for pain (somatosensory cortex), and loss (precuneus, middle/posterior cingular gyrus). This pattern of activation developed over time. While in the early phases of exposure lower association areas, such as the extrastriate body area, were active, in the late phases activation in parietal and temporal association areas and the prefrontal cortex was more prominent. These findings are consistent with the conventional and contextual character of iconographic material, and further differentiate it from emotionally negatively valenced and high-arousing stimuli. In future studies, this neuroimaging assay may be useful in characterizing interpretive appraisal of material of negative emotional valence. © The Author (2017). Published by Oxford University Press.

Transient attenuation of visual evoked potentials during focal status epilepticus in a patient with occipital lobe epilepsy.

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Tsai, Meng-Han; Hsu, Shih-Pin; Huang, Chi-Ren; Chang, Chen-Sheng; Chuang, Yao-Chung

2010-06-01

Seizures originating in the occipital areas are relatively uncommon. They are usually characterized by visual hallucinations and illusions or other symptoms related to the eyes and vision. In a 54-year-old woman with occipital lobe epilepsy, complex visual hallucinations, illusions, and migraine-like headache constitute the major clinical manifestations. During focal status epilepticus, ictal electroencephalography revealed rhythmic focal spikes in the right occipital region, rapidly propagating to the right parietal and contralateral occipital areas. Ictal brain single-photon emission computed topography revealed hyperperfusion of the right occipital region. Using a full-field pattern-shift visual evoked potential (VEP) study, we found that the P100 responses on both sides were markedly attenuated in amplitude during occipital focal status epilepticus, whereas the latencies of the VEPs were normal. The amplitude and morphology of P100 responses on both sides, however, returned to the normal range 7 days after cessation of the seizures. In addition to clinical seizure semiology, scalp EEG, SPECT and neuroimaging studies, VEP studies may be used as a supplementary examination tool to provide further information in the patients with occipital lobe seizures or epilepsies.

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

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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.

Observing complex action sequences: The role of the fronto-parietal mirror neuron system.

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Molnar-Szakacs, Istvan; Kaplan, Jonas; Greenfield, Patricia M; Iacoboni, Marco

2006-11-15

A fronto-parietal mirror neuron network in the human brain supports the ability to represent and understand observed actions allowing us to successfully interact with others and our environment. Using functional magnetic resonance imaging (fMRI), we wanted to investigate the response of this network in adults during observation of hierarchically organized action sequences of varying complexity that emerge at different developmental stages. We hypothesized that fronto-parietal systems may play a role in coding the hierarchical structure of object-directed actions. The observation of all action sequences recruited a common bilateral network including the fronto-parietal mirror neuron system and occipito-temporal visual motion areas. Activity in mirror neuron areas varied according to the motoric complexity of the observed actions, but not according to the developmental sequence of action structures, possibly due to the fact that our subjects were all adults. These results suggest that the mirror neuron system provides a fairly accurate simulation process of observed actions, mimicking internally the level of motoric complexity. We also discuss the results in terms of the links between mirror neurons, language development and evolution.

Functional Magnetic Resonance Imaging in the Presurgical Evaluation of Brain Vascular Malformations

International Nuclear Information System (INIS)

Montes, Natalia; Herrera, Diego A; Vargas Sergio A

2010-01-01

Objective: To describe our experience in presurgical evaluation of intracranial vascular malformations by means of functional magnetic resonance (fMRI). Method: To evaluate eight patients with cerebral vascular malformations (seven arterio-venous malformation [AVM ] and one cavernous malformation) to send to the eloquent cortex with RMf pre-surgical mapping is assessed. Used a technique that is dependent on the level of oxygen (BOLD) to locate these areas in the cerebral vascular malformation, by applying different paradigms. Results: We found one AVM at the right temporal lobe with activation of the parahipocampal gyrus at the contralateral side using a memory paradigm; another patient with an AVM at the right mesotemporal lobe showed activation of visual and spatial memory of the contralateral hippocampus and parahippocampus. One patient with an AVM at the left parietal lobe without compromise of sensorial and motor cortex; a cavernous malformation at the left angular gyrus with hemispheric language dominance in that side; one right thalamic AVM, one periventricular AVM bilateral language dominance; one left occipital AVM with decreased activation in visual association cortex; one temporoccipital AVM with left language dominance and neurovascular uncoupling. Conclusion: fMRI can delineate anatomically the relationship between the lesion and eloquent cortex, providing useful information for presurgical planning and allowing risk estimation of intervention.

"Opening an emotional dimension in me": changes in emotional reactivity and emotion regulation in a case of executive impairment after left fronto-parietal damage.

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Salas, Christian E; Radovic, Darinka; Yuen, Kenneth S L; Yeates, Giles N; Castro, O; Turnbull, Oliver H

2014-01-01

Dysexecutive impairment is a common problem after brain injury, particularly after damage to the lateral surface of the frontal lobes. There is a large literature describing the cognitive deficits associated with executive impairment after dorsolateral damage; however, little is known about its impact on emotional functioning. This case study describes changes in a 72-year-old man (Professor F) who became markedly dysexecutive after a left fron-to-parietal stroke. Professor F's case is remarkable in that, despite exhibiting typical executive impairments, abstraction and working memory capacities were spared. Such preservation of insight-related capacities allowed him to offer a detailed account of his emotional changes. Quantitative and qualitative tools were used to explore changes in several well-known emotional processes. The results suggest that Professor F's two main emotional changes were in the domain of emotional reactivity (increased experience of both positive and negative emotions) and emotion regulation (down-regulation of sadness). Professor F related both changes to difficulties in his thinking process, especially a difficulty generating and manipulating thoughts during moments of negative arousal. These results are discussed in relation to the literature on executive function and emotion regulation. The relevance of these findings for neuropsychological rehabilitation and for the debate on the neural basis of emotional processes is addressed.

Similar patterns of neural activity predict memory function during encoding and retrieval.

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Kragel, James E; Ezzyat, Youssef; Sperling, Michael R; Gorniak, Richard; Worrell, Gregory A; Berry, Brent M; Inman, Cory; Lin, Jui-Jui; Davis, Kathryn A; Das, Sandhitsu R; Stein, Joel M; Jobst, Barbara C; Zaghloul, Kareem A; Sheth, Sameer A; Rizzuto, Daniel S; Kahana, Michael J

2017-07-15

Neural networks that span the medial temporal lobe (MTL), prefrontal cortex, and posterior cortical regions are essential to episodic memory function in humans. Encoding and retrieval are supported by the engagement of both distinct neural pathways across the cortex and common structures within the medial temporal lobes. However, the degree to which memory performance can be determined by neural processing that is common to encoding and retrieval remains to be determined. To identify neural signatures of successful memory function, we administered a delayed free-recall task to 187 neurosurgical patients implanted with subdural or intraparenchymal depth electrodes. We developed multivariate classifiers to identify patterns of spectral power across the brain that independently predicted successful episodic encoding and retrieval. During encoding and retrieval, patterns of increased high frequency activity in prefrontal, MTL, and inferior parietal cortices, accompanied by widespread decreases in low frequency power across the brain predicted successful memory function. Using a cross-decoding approach, we demonstrate the ability to predict memory function across distinct phases of the free-recall task. Furthermore, we demonstrate that classifiers that combine information from both encoding and retrieval states can outperform task-independent models. These findings suggest that the engagement of a core memory network during either encoding or retrieval shapes the ability to remember the past, despite distinct neural interactions that facilitate encoding and retrieval. Copyright © 2017 Elsevier Inc. All rights reserved.

Mapping of the Underlying Neural Mechanisms of Maintenance and Manipulation in Visuo-Spatial Working Memory Using An n-back Mental Rotation Task: A Functional Magnetic Resonance Imaging Study.

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Lamp, Gemma; Alexander, Bonnie; Laycock, Robin; Crewther, David P; Crewther, Sheila G

2016-01-01

Mapping of the underlying neural mechanisms of visuo-spatial working memory (WM) has been shown to consistently elicit activity in right hemisphere dominant fronto-parietal networks. However to date, the bulk of neuroimaging literature has focused largely on the maintenance aspect of visuo-spatial WM, with a scarcity of research into the aspects of WM involving manipulation of information. Thus, this study aimed to compare maintenance-only with maintenance and manipulation of visuo-spatial stimuli (3D cube shapes) utilizing a 1-back task while functional magnetic resonance imaging (fMRI) scans were acquired. Sixteen healthy participants (9 women, M = 23.94 years, SD = 2.49) were required to perform the 1-back task with or without mentally rotating the shapes 90° on a vertical axis. When no rotation was required (maintenance-only condition), a right hemispheric lateralization was revealed across fronto-parietal areas. However, when the task involved maintaining and manipulating the same stimuli through 90° rotation, activation was primarily seen in the bilateral parietal lobe and left fusiform gyrus. The findings confirm that the well-established right lateralized fronto-parietal networks are likely to underlie simple maintenance of visuo-spatial stimuli. The results also suggest that the added demand of manipulation of information maintained online appears to require further neural recruitment of functionally related areas. In particular mental rotation of visuospatial stimuli required bilateral parietal areas, and the left fusiform gyrus potentially to maintain a categorical or object representation. It can be concluded that WM is a complex neural process involving the interaction of an increasingly large network.

Segmentation of the cingulum bundle in the human brain: a new perspective based on DSI tractography and fiber dissection study

Directory of Open Access Journals (Sweden)

Yupeng Wu

2016-09-01

Full Text Available The cingulum bundle (CB is a critical white matter fiber tract in the brain, which forms connections between the frontal lobe, parietal lobe, and temporal lobe. In non-human primates, the CB is actually divided into distinct subcomponents on the basis of corticocortical connections. However, at present, no study has verified similar distinct subdivisions in the human brain. In this study, we reconstructed these distinct subdivisions in the human brain, and determined their exact cortical connections using high definition fiber tracking (HDFT technique on 10 healthy adults and a 488-subject template from the Human Connectome Project (HCP-488. Fiber dissections were performed to verify tractography results. Five CB segments were identified. CB-I ran from the subrostral areas to the precuneus and splenium, encircling the corpus callosum. CB-II arched around the splenium and extended anteriorly above the corpus callosum to the medial aspect of the superior frontal gyrus. CB-III connected the superior parietal lobule and precuneus with the medial aspect of the superior frontal gyrus. CB-IV was a relatively minor subcomponent from the superior parietal lobule and precuneus to the frontal region. CB-V, the para-hippocampal cingulum, stemmed from the medial temporal lobe and fanned out to the occipital lobes. Our findings not only provide a more accurate and detailed description on the associated architecture of the subcomponents within the CB, but also offer new insights into the functional role of the CB in the human brain.

Parietal lesion effects on cued recall following pair associate learning.

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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.

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

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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.

Sports-related and gender differences on neuropsychological measures of frontal lobe functioning.

Science.gov (United States)

Ryan, Jeanne P; Atkinson, Thomas M; Dunham, Katherine T

2004-01-01

To determine similarities and differences in the performance of female and male athletes on neuropsychological measures of frontal lobe functioning. A cross-sectional study of male and female college-aged athletes involved in one of the following sports: hockey, basketball, softball, lacrosse, soccer, swimming, and track. Division III college. A total of 262 athletes (male, n=157; female, n=105) participated in the study. Controlled Oral Word Association (letters F, A, S), Cognitive Assessment System (Planned Codes, Planned Connections, Number Detection), and WAIS-R-NI Vocabulary were administered to all athletes. MANCOVA was performed with gender and sport as fixed factors. Female athletes displayed faster and more accurate performance on perceptual-motor tasks (Pgender and sport. Gender- and sport-specific performances on perceptual-motor and verbal fluency tasks were found. Adding cognitive components to base functions eliminates gender- and sports-related distinctions, suggesting that existing differences are related to basic, fundamental skills, which are inherent and practiced within the respective sport. Understanding the differences and similarities across sports and gender on various neurocognitive measures is relevant for determining group differences in studies examining the consequences of mild traumatic brain injury among athletes.

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

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

Regional homogeneity and functional connectivity patterns in major depressive disorder, cognitive vulnerability to depression and healthy subjects.

Science.gov (United States)

Sun, Hui; Luo, Lizhu; Yuan, Xinru; Zhang, Lu; He, Yini; Yao, Shuqiao; Wang, Jiaojian; Xiao, Jing

2018-08-01

Cognitive vulnerability to depression (CVD) is a high risk for depressive disorder. Recent studies focus on individuals with CVD to determine the neural basis of major depressive disorder (MDD) neuropathology. However, whether CVD showed specific or similar brain functional activity and connectivity patterns, compared to MDD, remain largely unknown. Here, using resting-state functional magnetic resonance imaging in subjects with CVD, healthy controls (HC) and MDD, regional homogeneity (ReHo) and resting-state functional connectivity (R-FC) analyses were conducted to assess local synchronization and changes in functional connectivity patterns. Significant ReHo differences were found in right posterior lobe of cerebellum (PLC), left lingual gyrus (LG) and precuneus. Compared to HC, CVD subjects showed increased ReHo in the PLC, which was similar to the difference found between MDD and HC. Compared to MDD patients, CVD subjects showed decreased ReHo in PLC, LG, and precuneus. R-FC analyses found increased functional connections between LG and left inferior parietal lobule, posterior cingulate cortex, and dorsolateral prefrontal cortex in CVD compared to both HC and MDD. Moreover, Regional mean ReHo values were positively correlated with Center for Epidemiologic Studies Depression Scale scores. These analyses revealed that PLC and functional connections between LG and left inferior parietal lobule, posterior cingulate cortex, and dorsolateral prefrontal cortex may be a potential marker for CVD. Copyright © 2018 Elsevier B.V. All rights reserved.

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...

Research progress on neural mechanisms of primary insomnia by MRI

Directory of Open Access Journals (Sweden)

Man WANG

2018-04-01

Full Text Available In recent years, more and more researches focused on the neural mechanism of primary insomnia (PI, especially with the development and application of MRI, and researches of brain structure and function related with primary insomnia were more and more in-depth. According to the hyperarousal hypothesis, there are abnormal structure, function and metabolism under certain brain regions of the cortex and subcortex of primary insomnia patients, including amygdala, hippocampus, cingulate gyrus, insular lobe, frontal lobe and parietal lobe. This paper reviewed the research progress of neural mechanisms of primary insomnia by using MRI. DOI: 10.3969/j.issn.1672-6731.2018.03.003

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.

Patterns of longitudinal neural activity linked to different cognitive profiles in Parkinson’s disease

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Atsuko Nagano-Saito

2016-11-01

Full Text Available Mild cognitive impairment in Parkinson’s disease (PD has been linked with functional brain changes. Previously, using functional magnetic resonance imaging (fMRI, we reported reduced cortico-striatal activity in patients with PD who also had mild cognitive impairment (MCI versus those who did not (non-MCI. We followed up these patients to investigate the longitudinal effect on the neural activity. Twenty-four non-demented patients with Parkinson’s disease (non-MCI: 12, MCI; 12 were included in the study. Each participant underwent two fMRIs while performing the Wisconsin Card Sorting Task 20 months apart. The non-MCI patients recruited the usual cognitive corticostriatal loop at the first and second sessions (Time 1 and Time 2, respectively. However, decreased activity was observed in the cerebellum and occipital area and increased activity was observed in the medial prefrontal cortex and parietal lobe during planning set-shift at Time 2. Increased activity in the precuneus was also demonstrated while executing set-shifts at Time 2. The MCI patients revealed more activity in the frontal, parietal and occipital lobes during planning set-shifts, and in the parietal and occipital lobes, precuneus, and cerebellum, during executing set-shift at Time 2. Analysis regrouping of both groups of PD patients revealed that hippocampal and thalamic activity at Time 1 was associated with less cognitive decline over time. Our results reveal that functional alteration along the time-points differed between the non-MCI and MCI patients. They also underline the importance of preserving thalamic and hippocampal function with respect to cognitive decline over time.

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

Science.gov (United States)

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.

I remember you: a role for memory in social cognition and the functional neuroanatomy of their interaction.

Science.gov (United States)

Spreng, R Nathan; Mar, Raymond A

2012-01-05

Remembering events from the personal past (autobiographical memory) and inferring the thoughts and feelings of other people (mentalizing) share a neural substrate. The shared functional neuroanatomy of these processes has been demonstrated in a meta-analysis of independent task domains (Spreng, Mar & Kim, 2009) and within subjects performing both tasks (Rabin, Gilboa, Stuss, Mar, & Rosenbaum, 2010; Spreng & Grady, 2010). Here, we examine spontaneous low-frequency fluctuations in fMRI BOLD signal during rest from two separate regions key to memory and mentalizing, the left hippocampus and right temporal parietal junction, respectively. Activity in these two regions was then correlated with the entire brain in a resting-state functional connectivity analysis. Although the left hippocampus and right temporal parietal junction were not correlated with each other, both were correlated with a distributed network of brain regions. These regions were consistent with the previously observed overlap between autobiographical memory and mentalizing evoked brain activity found in past studies. Reliable patterns of overlap included the superior temporal sulcus, anterior temporal lobe, lateral inferior parietal cortex (angular gyrus), posterior cingulate cortex, dorsomedial and ventral prefrontal cortex, inferior frontal gyrus, and the amygdala. We propose that the functional overlap facilitates the integration of personal and interpersonal information and provides a means for personal experiences to become social conceptual knowledge. This knowledge, in turn, informs strategic social behavior in support of personal goals. In closing, we argue for a new perspective within social cognitive neuroscience, emphasizing the importance of memory in social cognition. Copyright © 2010 Elsevier B.V. All rights reserved.

I remember you: A role for memory in social cognition and the functional neuroanatomy of their interaction

Science.gov (United States)

Spreng, R. Nathan; Mar, Raymond A.

2011-01-01

Remembering events from the personal past (autobiographical memory) and inferring the thoughts and feelings of other people (mentalizing) share a neural substrate. The shared functional neuroanatomy of these processes has been demonstrated in a meta-analysis of independent task domains (Spreng, Mar & Kim, 2009) and within subjects performing both tasks (Rabin, Gilboa, Stuss, Mar, & Rosenbaum, 2010; Spreng & Grady, 2010). Here, we examine spontaneous low-frequency fluctuations in fMRI BOLD signal during rest from two separate regions key to memory and mentalizing, the left hippocampus and right temporal parietal junction, respectively. Activity in these two regions was then correlated with the entire brain in a resting-state functional connectivity analysis. Although the left hippocampus and right temporal parietal junction were not correlated with each other, both were correlated with a distributed network of brain regions. These regions were consistent with the previously observed overlap between autobiographical memory and mentalizing evoked brain activity found in past studies. Reliable patterns of overlap included the superior temporal sulcus, anterior temporal lobe, lateral inferior parietal cortex (angular gyrus), posterior cingulate cortex, dorsomedial and ventral prefrontal cortex, inferior frontal gyrus, and the amygdala. We propose that the functional overlap facilitates the integration of personal and interpersonal information and provides a means for personal experiences to become social conceptual knowledge. This knowledge, in turn, informs strategic social behavior in support of personal goals. In closing, we argue for a new perspective within social cognitive neuroscience, emphasizing the importance of memory in social cognition. PMID:21172325

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.

SPM analysis of brain perfusion SPECT and F-18 FDG PET in the Korean autosomal dominant nocturnal frontal lobe epilepsy family

International Nuclear Information System (INIS)

Won, Kyoung Sook; Zeon, Seok Kil

2004-01-01

This study attempted to investigate the specific pattern of brain perfusion and glucose metabolism in the Korean autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) family. Using Tc-99m ECD brain perfusion SPECT. we assessed brain perfusion in 6 patients at interictal period and 5 patients at ictal period. Interictal F-18 FDG PET was performed on 6 affected family members. The scans were statistically analyzed by using statistical parametric mapping (SPM99). The data of the affected family members were compared to those of the control subjects. Interictal F-18 FDG PET SPM group analysis showed decreased glucose metabolism over the left middle and superior frontal gyri and the left central regions including the anterior parietal lobe. There was a less pronounced decrease in glucose uptake in the right anterior superior frontal gyrus. Interictal brain perfusion SPECT SPM group analysis showed similar pattern of decreased perfusion compared to those of interictal F-18 FDG PET. Ictal brain perfusion SPECT SPM group analysis revealed increased perfusion over the left pre-and postcentral gyri and less pronounced increased perfusion in the right postcentral gyrus. lnterictal F -18 PET and brain perfusion SPECT SPM group analysis suggest that major abnormalities of ADNFLE family are in the left frontal lobe. These findings may be helpful to elucidate the pathophysiological mechanism of this rare disease entity

SPM analysis of brain perfusion SPECT and F-18 FDG PET in the Korean autosomal dominant nocturnal frontal lobe epilepsy family

Energy Technology Data Exchange (ETDEWEB)

Won, Kyoung Sook; Zeon, Seok Kil [Keimyung University Dongsan Medical Center, Daegu (Korea, Republic of)

2004-07-01

This study attempted to investigate the specific pattern of brain perfusion and glucose metabolism in the Korean autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) family. Using Tc-99m ECD brain perfusion SPECT. we assessed brain perfusion in 6 patients at interictal period and 5 patients at ictal period. Interictal F-18 FDG PET was performed on 6 affected family members. The scans were statistically analyzed by using statistical parametric mapping (SPM99). The data of the affected family members were compared to those of the control subjects. Interictal F-18 FDG PET SPM group analysis showed decreased glucose metabolism over the left middle and superior frontal gyri and the left central regions including the anterior parietal lobe. There was a less pronounced decrease in glucose uptake in the right anterior superior frontal gyrus. Interictal brain perfusion SPECT SPM group analysis showed similar pattern of decreased perfusion compared to those of interictal F-18 FDG PET. Ictal brain perfusion SPECT SPM group analysis revealed increased perfusion over the left pre-and postcentral gyri and less pronounced increased perfusion in the right postcentral gyrus. lnterictal F -18 PET and brain perfusion SPECT SPM group analysis suggest that major abnormalities of ADNFLE family are in the left frontal lobe. These findings may be helpful to elucidate the pathophysiological mechanism of this rare disease entity.

Differences in graph theory functional connectivity in left and right temporal lobe epilepsy.

Science.gov (United States)

Chiang, Sharon; Stern, John M; Engel, Jerome; Levin, Harvey S; Haneef, Zulfi

2014-12-01

To investigate lateralized differences in limbic system functional connectivity between left and right temporal lobe epilepsy (TLE) using graph theory. Interictal resting state fMRI was performed in 14 left TLE patients, 11 right TLE patients, and 12 controls. Graph theory analysis of 10 bilateral limbic regions of interest was conducted. Changes in edgewise functional connectivity, network topology, and regional topology were quantified, and then left and right TLE were compared. Limbic edgewise functional connectivity was predominantly reduced in both left and right TLE. More regional connections were reduced in right TLE, most prominently involving reduced interhemispheric connectivity between the bilateral insula and bilateral hippocampi. A smaller number of limbic connections were increased in TLE, more so in left than in right TLE. Topologically, the most pronounced change was a reduction in average network betweenness centrality and concurrent increase in left hippocampal betweenness centrality in right TLE. In contrast, left TLE exhibited a weak trend toward increased right hippocampal betweenness centrality, with no change in average network betweenness centrality. Limbic functional connectivity is predominantly reduced in both left and right TLE, with more pronounced reductions in right TLE. In contrast, left TLE exhibits both edgewise and topological changes that suggest a tendency toward reorganization. Network changes in TLE and lateralized differences thereof may have important diagnostic and prognostic implications. Published by Elsevier B.V.

Study of acupuncture point Liv 3 with functional MRI

International Nuclear Information System (INIS)

Wang Wei; Li Kuncheng; Hao Jing; Yang Yanhui; Shan Baoci; Yan Bin; Li Ke; Xu Jianyang

2006-01-01

Objective: To investigate the mechanism of acupuncture point Liv3 (Taichong) and possible post-effect of acupuncture by using functional magnetic resonance imaging (fMRI) Methods: Eighteen healthy right-handed volunteers participated in the experiment. The experiment used single block design, including rest state, stimulation state and post effect state (PE). Everyone only received acupuncture at one of the two stimulations, that was: true acupuncture (TA) at right Liv3 or sham acupoint (SA) near Liv3, in which 10 subjects participated in TA and other 8 subjects in SA. The fMRI data were obtained from scanning the whole brain and were analyzed using SPM99. Significant changes of stimulation state or post effect state compared to rest state were accessed using t-statistics. The t-ratios were used to form the statistical parametric maps which showed brain activation areas by acupuncture above P< 0.001. In order to remove the effects of other non-acupuncture factors, we used the mask function to exclude the areas activated by SA from the areas activated by TA. Results: The brain activation areas during TA for 10 subjects exclusive by SA for 8 subjects were showed on bilateral cerebella(t value is 10.06 and 9.82, respectively), prefrontal lobe (PF), superior parietal lobule (SPL, t value is 4.36 and 4.53, respectively) and inferior parietal lobule (IPL, t value is 3.94 and 4.95, respectively), occipital lobe, parahippocampal gyms, insula( t value is 3.82 and 5.51, respectively), thalamus, lentiform nucleus (t value is 3.24 and 4.40, respectively), contralateral temporal pole, anterior cingnlate cortex (ACC), and posterior cingulate cortex (PGC, all of P<0.01). The PE of TA for 10 subjects exclusive by 'PE' of SA for 8 subjects activated bilateral cerebella, PF, SPL, IPL, occipital lobe, lentiform nucleus, parahippocampal gyrus, ipsilateral tempoaral pole, hippocampus, insula, thalamus, contralateral head of nucleus caudate, corpus callosum, ACC, and PCC. Conclusion

A parietal biomarker for ADHD liability:As predicted by The Distributed Effects Perspective Model of ADHD

Directory of Open Access Journals (Sweden)

T. Sigi eHale

2015-05-01

Full Text Available Background: We previously hypothesized that poor task-directed sensory information processing should be indexed by increased weighting of right hemisphere (RH biased attention and visuo-perceptual brain functions during task operations, and have demonstrated this phenotype in ADHD across multiple studies, using multiple methodologies. However, in our recent Distributed Effects Model of ADHD, we surmised that this phenotype is not ADHD specific, but rather more broadly reflective of any circumstance that disrupts the induction and maintenance of an emergent task-directed neural architecture. Under this view, increased weighting of RH biased attention and visuo-perceptual brain functions is expected to generally index neurocognitive sets that are not optimized for task-directed thought and action, and when durable expressed, liability for ADHD. Method: The current study tested this view by examining whether previously identified rightward parietal EEG asymmetry in ADHD was associated with common ADHD characteristics and comorbidities (i.e., ADHD risk factors. Results: Barring one exception (non-right handedness, we found that it was. Rightward parietal asymmetry was associated with carrying the DRD4-7R risk allele, being male, having mood disorder, and having anxiety disorder. However, differences in the specific expression of rightward parietal asymmetry were observed, which are discussed in relation to possible unique mechanisms underlying ADHD liability in different ADHD RFs. Conclusion: Rightward parietal asymmetry appears to be a durable feature of ADHD liability, as predicted by the Distributed Effects Perspective Model of ADHD. Moreover, variability in the expression of this phenotype may shed light on different sources of ADHD liability.

Turbulent measurements in the lobe mixer of a turbofan engine. Turbofan engine lobe mixer nagare no ranryu keisoku

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Makoto; Ogawa, Yuji; Arakawa, Chuichi; Tagori, Tetsuo [Ishikawajima-Harima Heavy Industries, Co., Ltd., Tokyo, (Japan) Nippon Steel Corp., Tokyo, (Japan) The Univ. of Tokyo, Tokyo, (Japan). Faculty of Engineering The Univ. of Tsukuba, Tsukuba, (Japan)

1990-01-25

In order to examine the flow generated by the lobe mixer of a turbofan engine precisely, after measuring a three dimensional turbulent flow by a hot-wire anemometer, the mixing process of a bypass flow and a core flow with cross-sectional vortexes, and factors generating the vortex were clarified experimentally using the scale model of an exhaust duct with the lobe mixer. As a result, the mixing process was strongly affected by a lobe tip figure and a lobe figure near a center-body, and affected by the minimum gap between the lobe and center-body. The subsequent mixing process was scarcely affected by the ratio of a core flow velocity to a bypass flow one, although strongly affected by flow conditions on a lobe surface. Since the lobe mixer promoted the mixing around a center axis shifting a fast core flow outwards, it was unfavorable to mixing, however, it was expected to be useful for reducing engine jet noise. 3 refs., 7 figs.

Gender differences in brain regional homogeneity of healthy subjects after normal sleep and after sleep deprivation: a resting-state fMRI study.

Science.gov (United States)

Dai, Xi-Jian; Gong, Hong-Han; Wang, Yi-Xiang; Zhou, Fu-Qing; Min, You-Jiang; Zhao, Feng; Wang, Si-Yong; Liu, Bi-Xia; Xiao, Xiang-Zuo

2012-06-01

To explore the gender differences of brain regional homogeneity (ReHo) in healthy subjects during the resting-state, after normal sleep, and after sleep deprivation (SD) using functional magnetic resonance imaging (fMRI) and the ReHo method. Sixteen healthy subjects (eight males and eight females) each underwent the resting-state fMRI exams twice, i.e., once after normal sleep and again after 24h's SD. According to the gender and sleep, 16 subjects were all measured twice and divided into four groups: the male control group (MC), female control group (FC), male SD group (MSD), and female SD group (FSD). The ReHo method was used to calculate and analyze the data, SPM5 software was used to perform a two-sample T-test and a two-pair T-test with a P value right paracentral lobule (BA3/6), but in no obviously lower regions. Compared with the FC, the FSD showed significantly higher ReHo in bilateral parietal lobes (BA2/3), bilateral vision-related regions of occipital lobes (BA17/18/19), right frontal lobe (BA4/6), and lower ReHo in the right frontal lobe. Compared with the FC, the MC showed significantly higher ReHo in the left occipital lobe (BA18/19), and left temporal lobe (BA21), left frontal lobe, and lower ReHo in the right insula and in the left parietal lobe. Compared with the FSD, the MSD showed significantly higher ReHo in the left cerebellum posterior lobe (uvula/declive of vermis), left parietal lobe, and bilateral frontal lobes, and lower ReHo in the right occipital lobe (BA17) and right frontal lobe (BA4). The differences of brain activity in the resting state can be widely found not only between the control and SD group in a same gender group, but also between the male group and female group. Thus, we should take the gender differences into consideration in future fMRI studies, especially the treatment of brain-related diseases (e.g., depression). Copyright © 2012 Elsevier B.V. All rights reserved.

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.

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

Altered default network resting-state functional connectivity in adolescents with Internet gaming addiction.

Directory of Open Access Journals (Sweden)

Wei-na Ding

Full Text Available Excessive use of the Internet has been linked to a variety of negative psychosocial consequences. This study used resting-state functional magnetic resonance imaging (fMRI to investigate whether functional connectivity is altered in adolescents with Internet gaming addiction (IGA.Seventeen adolescents with IGA and 24 normal control adolescents underwent a 7.3 minute resting-state fMRI scan. Posterior cingulate cortex (PCC connectivity was determined in all subjects by investigating synchronized low-frequency fMRI signal fluctuations using a temporal correlation method. To assess the relationship between IGA symptom severity and PCC connectivity, contrast images representing areas correlated with PCC connectivity were correlated with the scores of the 17 subjects with IGA on the Chen Internet Addiction Scale (CIAS and Barratt Impulsiveness Scale-11 (BIS-11 and their hours of Internet use per week.There were no significant differences in the distributions of the age, gender, and years of education between the two groups. The subjects with IGA showed longer Internet use per week (hours (p<0.0001 and higher CIAS (p<0.0001 and BIS-11 (p = 0.01 scores than the controls. Compared with the control group, subjects with IGA exhibited increased functional connectivity in the bilateral cerebellum posterior lobe and middle temporal gyrus. The bilateral inferior parietal lobule and right inferior temporal gyrus exhibited decreased connectivity. Connectivity with the PCC was positively correlated with CIAS scores in the right precuneus, posterior cingulate gyrus, thalamus, caudate, nucleus accumbens, supplementary motor area, and lingual gyrus. It was negatively correlated with the right cerebellum anterior lobe and left superior parietal lobule.Our results suggest that adolescents with IGA exhibit different resting-state patterns of brain activity. As these alterations are partially consistent with those in patients with substance addiction, they support the

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.

Comparison of FDG-PET and IMP-SPECT in patients with dementia with Lewy bodies

International Nuclear Information System (INIS)

Ishii, Kazunari; Hosaka, Kayo; Mori, Tetsuya; Mori, Etsuro

2004-01-01

To investigate regional differences in cerebral glucose metabolism and blood flow of dementia with Lewy bodies (DLB), we studied 7 subjects with DLB and 20 normal controls using F-18 fluorodeoxyglucose (FDG) and positron emission tomography (PET) and then examined the same 7 subjects and 20 other normal controls with I-123 iodoamphetamine (IMP) and single photon emission computed tomography (SPECT). The anatomically standardized images were produced with NEUROSTAT and the regional relative metabolic and perfusional values were calculated. The mean reduction ratios of FDG uptake in the DLB group relative to the mean normal controls in the parietal lobe and occipital lobe were 0.72 and 0.83, respectively, while the corresponding mean reduction ratios of IMP uptake were 0.81 and 0.88, respectively. In the DLB group, parietal FDG uptake was significantly lower than parietal IMP uptake (p<0.05), occipital FDG uptake was significantly lower than occipital IMP uptake (p<0.05), and parietal IMP uptake was significantly lower than occipital IMP uptake (p<0.01), but there was no difference between parietal and occipital FDG uptake. Our findings suggest that parietal metabolism and perfusion are severely affected in DLB patients, though the occipital metabolic and perfusional reduction is thought to be a feature of DLB. FDG-PET is thought to be superior to IMP-SPECT in detecting functional changes in the DLB brain. (author)

Developmental trajectories of the fronto-temporal lobes from infancy to early adulthood in healthy individuals.

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Tanaka, Chiaki; Matsui, Mie; Uematsu, Akiko; Noguchi, Kyo; Miyawaki, Toshio

2012-01-01

Brain development during early life in healthy individuals is rapid and dynamic, indicating that this period plays a very important role in neural and functional development. The frontal and temporal lobes are known to play a particularly important role in cognition. The study of healthy frontal and temporal lobe development in children is therefore of considerable importance. A better understanding of how these brain regions develop could also aid in the diagnosis and treatment of neurodevelopmental disorders. Some developmental studies have used magnetic resonance imaging (MRI) to examine infant brains, but it remains the case that relatively little is known about cortical brain development in the first few years of life. In the present study we examined whole brain, temporal lobe and frontal lobe developmental trajectories from infancy to early adulthood in healthy individuals, considering gender and brain hemisphere differences. We performed a cross-sectional, longitudinal morphometric MRI study of 114 healthy individuals (54 females and 60 males) aged 1 month to 25 years old (mean age ± SD 8.8 ± 6.9). We measured whole brain, temporal and frontal lobe gray matter (GM)/white matter (WM) volumes, following previously used protocols. There were significant non-linear age-related volume changes in all regions. Peak ages of whole brain, temporal lobe and frontal lobe development occurred around pre-adolescence (9-12 years old). GM volumes for all regions increased significantly as a function of age. Peak age was nevertheless lobe specific, with a pattern of earlier peak ages for females in both temporal and frontal lobes. Growth change in whole brain GM volume was larger in males than in females. However, GM volume growth changes for the temporal and frontal lobes showed a somewhat different pattern. GM volume for both temporal and frontal lobes showed a greater increase in females until around 5-6 years old, at which point this tendency reversed (GM volume

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

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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.

Clinical study on temporal lobe epilepsy in childhood caused by temporal lobe space occupying lesions

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Matsuura, Mariko; Oguni, Hirokazu; Funatsuka, Makoto; Osawa, Makiko; Yamane, Fumitaka; Hori, Tomokatsu; Shimizu, Hiroyuki

2008-01-01

We studied the clinicoelectrical and neuroimaging features of 11 patients with symptomatic temporal lobe epilepsy (TLE) caused by temporal lobe space occupying lesions (SOLs), and compared its characteristics with those of 19 mesial TLE (MTLE) patients. Brain MRI demonstrated SOLs in the mesiotemporal lobe in 9, and laterotemporal lobe in the remaining 2 patients. Ten of the 11 patients successfully underwent surgery, which revealed tumors in 7 and focal cortical dysplasia in 3 patients. Comparisons of the clinical features between those with space occupying TLE (SOTLE) and MTLE showed that both conditions shared the same clinical seizure manifestations such as gastric uprising sensation or ictal fear and a favorable response to surgery. However, the patients with SOTLE had fewer febrile convulsion, and more frequent seizure recurrences as well as TLE EEG discharges and associations of the monophasic clinical course than those with MTLE. In addition, the MRI findings were characterized by unilateral hippocampal atrophy in MTLE and expanding or SOLs in the SOTLE group. Children with complex partial seizures of suspected temporal lobe origin should undergo extensive neuroimaging evaluation. (author)

The Responsive Amygdala: Treatment-induced Alterations in Functional Connectivity in Pediatric Complex Regional Pain Syndrome

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Simons, LE; Pielech, M; Erpelding, N; Linnman, C; Moulton, E; Sava, S; Lebel, A; Serrano, P; Sethna, N; Berde, C; Becerra, L; Borsook, D

2014-01-01

The amygdala is a key brain region with efferent and afferent neural connections that involve complex behaviors such as pain, reward, fear and anxiety. This study evaluated resting state functional connectivity of the amygdala with cortical and subcortical regions in a group of chronic pain patients (pediatric complex regional pain syndrome) with age-gender matched controls before and after intensive physical-biobehavioral pain treatment. Our main findings include (1) enhanced functional connectivity from the amygdala to multiple cortical, subcortical, and cerebellar regions in patients compared to controls, with differences predominantly in the left amygdala in the pre-treated condition (disease state); (2) dampened hyperconnectivity from the left amygdala to the motor cortex, parietal lobe, and cingulate cortex after intensive pain rehabilitation treatment within patients with nominal differences observed among healthy controls from Time 1 to Time 2 (treatment effects); (3) functional connectivity to several regions key to fear circuitry (prefrontal cortex, bilateral middle temporal lobe, bilateral cingulate, hippocampus) correlated with higher pain-related fear scores and (4) decreases in pain-related fear associated with decreased connectivity between the amygdala and the motor and somatosensory cortex, cingulate, and frontal areas. Our data suggest that there are rapid changes in amygdala connectivity following an aggressive treatment program in children with chronic pain and intrinsic amygdala functional connectivity activity serving as a potential indicator of treatment response. PMID:24861582

Representation of thermal information in the antennal lobe of leaf-cutting ants

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Markus eRuchty

2010-11-01

Full Text Available Insects are equipped with various types of antennal sensilla, which house thermosensitive neurons adapted to receive different parameters of the thermal environment for a variety of temperature-guided behaviors. In the leaf-cutting ant Atta vollenweideri, the physiology and the morphology of the thermosensitive sensillum coeloconicum (Sc has been thoroughly investigated. However, the central projections of its receptor neurons are unknown. Here we selectively stained the three neurons found in single Sc and tracked their axons into the brain of Atta vollenweideri workers. Each of the three axons terminates in a single glomerulus of the antennal lobe (Sc-glomeruli. Two of the innervated glomeruli are adjacent to each other and are located laterally, while the third one is clearly separated and located medially in the antennal lobe. Using two-photon Ca2+ imaging of antennal lobe projection neurons, we studied where in the antennal lobe thermal information is represented. In the 11 investigated antennal lobes, we found up to 10 different glomeruli in a single specimen responding to temperature stimulation. Both, warm- and cold-sensitive glomeruli could be identified. The thermosensitive glomeruli were mainly located in the medial part of the antennal lobe. Based on the general representation of thermal information in the antennal lobe and functional data on the Sc-glomeruli we conclude that temperature stimuli received by Sc are processed in the medial of the three target glomeruli. The present study reveals an important role of the antennal lobe in temperature processing and links a specific thermosensitive neuron to its central target glomerulus.

Temporo-Parietal Junction Activity in Theory-of-Mind Tasks: Falseness, Beliefs, or Attention

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Aichhorn, Markus; Perner, Josef; Weiss, Benjamin; Kronbichler, Martin; Staffen, Wolfgang; Ladurner, Gunther

2009-01-01

By combining the false belief (FB) and photo (PH) vignettes to identify theory-of-mind areas with the false sign (FS) vignettes, we re-establish the functional asymmetry between the left and right temporo-parietal junction (TPJ). The right TPJ (TPJ-R) is specially sensitive to processing belief information, whereas the left TPJ (TPJ-L) is equally…

Role of JAK/STAT signaling in neuroepithelial stem cell maintenance and proliferation in the Drosophila optic lobe

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Wang, Wei; Li, Yonggang; Zhou, Liya; Yue, Haitao [School of Life Sciences, Tsinghua University, Beijing 100084 (China); Luo, Hong, E-mail: luohong@mail.tsinghua.edu.cn [School of Life Sciences, Tsinghua University, Beijing 100084 (China)

2011-07-15

Highlights: {yields} JAK/STAT activity is graded in the Drosophila optic lobe neuroepithelium. {yields} Inactivation of JAK signaling causes disintegration of the optic lobe neuroepithelium and depletion of the neuroepithelial stem cells. {yields} JAK pathway overactivation promotes neuroepithelial overgrowth. {yields} Notch signaling acts downstream of JAK/STAT to promote neuroepithelial growth and expansion. -- Abstract: During Drosophila optic lobe development, proliferation and differentiation must be tightly modulated to reach its normal size for proper functioning. The JAK/STAT pathway plays pleiotropic roles in Drosophila development and in the larval brain, has been shown to inhibit medulla neuroblast formation. In this study, we find that JAK/STAT activity is required for the maintenance and proliferation of the neuroepithelial stem cells in the optic lobe. In loss-of-function JAK/STAT mutant brains, the neuroepithelial cells lose epithelial cell characters and differentiate prematurely while ectopic activation of this pathway is sufficient to induce neuroepithelial overgrowth in the optic lobe. We further show that Notch signaling acts downstream of JAK/STAT to control the maintenance and growth of the optic lobe neuroepithelium. Thus, in addition to its role in suppression of neuroblast formation, the JAK/STAT pathway is necessary and sufficient for optic lobe neuroepithelial growth.

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

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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

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.

Cognitive consequences of coexisting temporal lobe developmental malformations and hippocampal sclerosis.

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Martin, R; Dowler, R; Gilliam, F; Faught, E; Morawetz, R; Kuzniecky, R

1999-09-11

To characterize patterns of cognitive functioning in a well-defined group of patients with MRI-identified coexisting left temporal lobe developmental malformations (TLDM) and mesial temporal sclerosis (MTS), and to examine neuropsychological outcome in this dual-pathology group following epilepsy surgery. Cognitive functioning in patients with left TLDM and MTS (n = 15) was compared with patients with isolated left MTS (n = 40). TLDM and MTS were identified by high-quality MRI protocol. Patients were administered a battery of neuropsychology tests as part of their presurgical workup for possible epilepsy surgery. Unilateral temporal lobe resection was performed on 10 of the dual-pathology patients and 34 of the isolated MTS patients. Postoperative cognitive performance was also assessed. Both groups displayed impairments in verbal and visual memory, language, and academic achievement. Performance on measures of psychometric intelligence, executive function, and attention were not impaired and were similar between groups. Presence of dual pathology was associated with a significantly less efficient verbal encoding strategy on the word list learning task. Postoperatively, declines were noted for both groups across tasks of verbal memory and language. Groups were not different significantly in terms of neuropsychological outcome after surgery. Patients with coexisting TLDM and MTS have impaired cognitive functioning similar to MTS patients-in particular, with regard to episodic memory and language deficits. Temporal lobe resection produces similar cognitive changes in both groups.

Observational learning of new movement sequences is reflected in fronto-parietal coherence.

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Jurjen van der Helden

Full Text Available Mankind is unique in her ability for observational learning, i.e. the transmission of acquired knowledge and behavioral repertoire through observation of others' actions. In the present study we used electrophysiological measures to investigate brain mechanisms of observational learning. Analysis investigated the possible functional coupling between occipital (alpha and motor (mu rhythms operating in the 10 Hz frequency range for translating "seeing" into "doing". Subjects observed movement sequences consisting of six consecutive left or right hand button presses directed at one of two target-buttons for subsequent imitation. Each movement sequence was presented four times, intervened by short pause intervals for sequence rehearsal. During a control task subjects observed the same movement sequences without a requirement for subsequent reproduction. Although both alpha and mu rhythms desynchronized during the imitation task relative to the control task, modulations in alpha and mu power were found to be largely independent from each other over time, arguing against a functional coupling of alpha and mu generators during observational learning. This independence was furthermore reflected in the absence of coherence between occipital and motor electrodes overlaying alpha and mu generators. Instead, coherence analysis revealed a pair of symmetric fronto-parietal networks, one over the left and one over the right hemisphere, reflecting stronger coherence during observation of movements than during pauses. Individual differences in fronto-parietal coherence were furthermore found to predict imitation accuracy. The properties of these networks, i.e. their fronto-parietal distribution, their ipsilateral organization and their sensitivity to the observation of movements, match closely with the known properties of the mirror neuron system (MNS as studied in the macaque brain. These results indicate a functional dissociation between higher order areas for

Composing lexical versus functional adjectives: Evidence for uniformity in the left temporal lobe.

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Zhang, Linmin; Pylkkänen, Liina

2018-04-24

Featural information (e.g., color or shape) allows interlocutors to focus their attention on the specific items under discussion from the vast set of possibilities in the environment. Intriguingly, when they are used to modify and restrict nouns, adjectives can either carry featural information themselves (e.g., green car) or retrieve featural information from the context (e.g., somebody points at a car and claims that she has the same car or a different car). Do the processing of same/different car and green car share neural correlates? For the composition of nouns with feature-carrying adjectives, prior work revealed early compositional effects (roughly 200 ms after noun onset) in the left anterior temporal lobe. However, although we know that such effects do not extend to cases of numeral quantification, which add no conceptual features to the noun (e.g., two boats), we do not know whether they extend to functional adjectives that themselves introduce no features, but instead reference features in the context. To address this question, we measured magnetoencephalography (MEG) during the processing of five types of noun phrases (NPs): same NPs (e.g., same star), different NPs (e.g., different star), color NPs (e.g., green star), comparative NPs (e.g., larger star), and another NPs (e.g., another star). Our main finding was that between 185 to 240 ms after noun onset, same and different NPs patterned with the color NPs in their elicited left temporal lobe activity, and same NPs even trended toward higher amplitudes than the color NPs. This shows that the mechanism driving combinatory effects in the left temporal cortex does not require the input words to directly name conceptual features, as long as the words reference featural information in the context, and that overlapping neural correlates underlie the composition of featural information from both linguistic and nonlinguistic sources.

Q-Ball of Inferior Fronto-Occipital Fasciculus and Beyond

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Amirbekian, Bagrat; Berger, Mitchel S.; Henry, Roland G.

2014-01-01

The inferior fronto-occipital fasciculus (IFOF) is historically described as the longest associative bundle in the human brain and it connects various parts of the occipital cortex, temporo-basal area and the superior parietal lobule to the frontal lobe through the external/extreme capsule complex. The exact functional role and the detailed anatomical definition of the IFOF are still under debate within the scientific community. In this study we present a fiber tracking dissection of the right and left IFOF by using a q-ball residual-bootstrap reconstruction of High-Angular Resolution Diffusion Imaging (HARDI) data sets in 20 healthy subjects. By defining a single seed region of interest on the coronal fractional anisotropy (FA) color map of each subject, we investigated all the pathways connecting the parietal, occipital and posterior temporal cortices to the frontal lobe through the external/extreme capsule. In line with recent post-mortem dissection studies we found more extended anterior-posterior association connections than the “classical” fronto-occipital representation of the IFOF. In particular the pathways we evidenced showed: a) diffuse projections in the frontal lobe, b) fronto-parietal lobes connections trough the external capsule in almost all the subjects and c) widespread connections in the posterior regions. Our study represents the first consistent in vivo demonstration across a large group of individuals of these novel anterior and posterior terminations of the IFOF detailed described only by post-mortem anatomical dissection. Furthermore our work establishes the feasibility of consistent in vivo mapping of this architecture with independent in vivo methodologies. In conclusion q-ball tractography dissection supports a more complex definition of IFOF, which includes several subcomponents likely underlying specific function. PMID:24945305

Q-ball of inferior fronto-occipital fasciculus and beyond.

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Eduardo Caverzasi

Full Text Available The inferior fronto-occipital fasciculus (IFOF is historically described as the longest associative bundle in the human brain and it connects various parts of the occipital cortex, temporo-basal area and the superior parietal lobule to the frontal lobe through the external/extreme capsule complex. The exact functional role and the detailed anatomical definition of the IFOF are still under debate within the scientific community. In this study we present a fiber tracking dissection of the right and left IFOF by using a q-ball residual-bootstrap reconstruction of High-Angular Resolution Diffusion Imaging (HARDI data sets in 20 healthy subjects. By defining a single seed region of interest on the coronal fractional anisotropy (FA color map of each subject, we investigated all the pathways connecting the parietal, occipital and posterior temporal cortices to the frontal lobe through the external/extreme capsule. In line with recent post-mortem dissection studies we found more extended anterior-posterior association connections than the "classical" fronto-occipital representation of the IFOF. In particular the pathways we evidenced showed: a diffuse projections in the frontal lobe, b fronto-parietal lobes connections trough the external capsule in almost all the subjects and c widespread connections in the posterior regions. Our study represents the first consistent in vivo demonstration across a large group of individuals of these novel anterior and posterior terminations of the IFOF detailed described only by post-mortem anatomical dissection. Furthermore our work establishes the feasibility of consistent in vivo mapping of this architecture with independent in vivo methodologies. In conclusion q-ball tractography dissection supports a more complex definition of IFOF, which includes several subcomponents likely underlying specific function.

Hierarchical clustering of Alzheimer and 'normal' brains using elemental concentrations and glucose metabolism determined by PIXE, INAA and PET

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Cutts, D.A.; Spyrou, N.M.

2001-01-01

Brain tissue samples, obtained from the Alzheimer Disease Brain Bank, Institute of Psychiatry, London, were taken from both left and right hemispheres of three regions of the cerebrum, namely the frontal, parietal and occipital lobes for both Alzheimer and 'normal' subjects. Trace element concentrations in the frontal lobe were determined for twenty six Alzheimer (15 male, 11 female) and twenty six 'normal' (8 male, 18 female) brain tissue samples. In the parietal lobe ten Alzheimer (2 male, 8 female) and ten 'normal' (8 male, 2 female) samples were taken along with ten Alzheimer (4 male, 6 female) and ten 'normal' (6 male, 4 female) from the occipital lobe. For the frontal lobe trace element concentrations were determined using proton induced X-ray emission (PIXE) analysis while in parietal and occipital regions instrumental neutron activation analysis (INAA) was used. Additionally eighteen Alzheimer (9 male, 9 female) and eighteen age matched 'normal' (8 male, 10 female) living subjects were examined using positron emission tomography (PET) in order to determine regional cerebral metabolic rates of glucose (rCMRGlu). The rCMRGlu of 36 regions of the brain was investigated including frontal, occipital and parietal lobes as in the trace element study. Hierarchical cluster analysis was applied to the trace element and glucose metabolism data to discover which variables in the resulting dendrograms displayed the most significant separation between Alzheimer and 'normal' subjects. (author)

Functional organization of the insula and inner perisylvian regions

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Jezzini, Ahmad; Caruana, Fausto; Stoianov, Ivilin; Gallese, Vittorio; Rizzolatti, Giacomo

2012-01-01

In the last few years, the insula has been the focus of many brain-imaging studies, mostly devoted to clarify its role in emotions and social communication. Physiological data, however, on which one may ground these correlative findings are almost totally lacking. Here, we investigated the functional properties of the insular cortex in behaving monkeys using intracortical microstimulation. Behavioral responses and heart rate changes were recorded. The results showed that the insula is functionally formed by two main subdivisions: (i) a sensorimotor field occupying the caudal–dorsal portion of the insula and appearing as an extension of the parietal lobe; and (ii) a mosaic of orofacial motor programs located in the anterior and centroventral insula sector. These programs show a progressive shift from dorsally located nonemotional motor programs (ingestive activity) to ventral ones laden with emotional and communicative content. The relationship between ingestive and other behaviors is discussed in an evolutionary perspective. PMID:22647599

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

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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.

The Effects of Taekwondo Training on Brain Connectivity and Body Intelligence.

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Kim, Young Jae; Cha, Eun Joo; Kim, Sun Mi; Kang, Kyung Doo; Han, Doug Hyun

2015-07-01

Many studies have reported that Taekwondo training could improve body perception, control and brain activity, as assessed with an electroencephalogram. This study aimed to assess body intelligence and brain connectivity in children with Taekwondo training as compared to children without Taekwondo training. Fifteen children with Taekwondo training (TKD) and 13 age- and sex-matched children who had no previous experience of Taekwondo training (controls) were recruited. Body intelligence, clinical characteristics and brain connectivity in all children were assessed with the Body Intelligence Scale (BIS), self-report, and resting state functional magnetic resonance imaging. The mean BIS score in the TKD group was higher than that in the control group. The TKD group showed increased low-frequency fluctuations in the right frontal precentral gyrus and the right parietal precuneus, compared to the control group. The TKD group showed positive cerebellum vermis (lobe VII) seed to the right frontal, left frontal, and left parietal lobe. The control group showed positive cerebellum seed to the left frontal, parietal, and occipital cortex. Relative to the control group, the TKD group showed increased functional connectivity from cerebellum seed to the right inferior frontal gyrus. To the best of our knowledge, this is the first study to assess the effect of Taekwondo training on brain connectivity in children. Taekwondo training improved body intelligence and brain connectivity from the cerebellum to the parietal and frontal cortex.

Tracing short connections of the temporo-parieto-occipital region in the human brain using diffusion spectrum imaging and fiber dissection.

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Wu, Yupeng; Sun, Dandan; Wang, Yong; Wang, Yunjie; Wang, Yibao

2016-09-01

The temporo-parieto-occipital (TPO) junction plays a unique role in human high-level neurological functions. Long-range fibers from and to this area have been described in detail but little is known about short TPO tracts mediating local connectivity. In this study, we performed high angular diffusion spectrum imaging (DSI) analyses to visualize the short TPO connections in the human brain. Fiber tracking was conducted on a subject-specific approach (10 subjects) and a template of 90 subjects (NTU-90 Atlas). Three tracts were identified: posterior segment of the superior longitudinal fasciculus (SLF-V), connecting the posterior part of the middle and inferior temporal gyri with the angular gyrus and supramarginal gyrus, vertical occipital fasciculus (VOF), connecting the inferior parietal with the lower temporal and occipital lobe, and a novel temporo-parietal (TP) connection, interconnecting the inferior temporal gyrus, middle temporal gyrus and fusiform gyrus, and inferior occipital lobe with the superior parietal lobe. These studies were complemented by fiber dissection techniques. It is the first study that demonstrated the trajectory and connectivity of the VOF using fiber dissection, as well as displayed the spatial relationship of the SLF-V with the cortex and the adjacent fiber bundles on one dissecting hemisphere. By providing a more accurate and detailed description of the local connectivity of the TPO junction, our findings help to develop new insights into its functional role in the human brain. Copyright © 2016 Elsevier B.V. All rights reserved.

Structural MRI research in patients with nasopharyngeal carcinoma following radiotherapy: A DTI and VBM study.

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Leng, Xi; Fang, Peng; Lin, Huan; An, Jie; Tan, Xin; Zhang, Chi; Wu, Donglin; Shen, Wen; Qiu, Shijun

2017-11-01

The aim of the present study was to investigate the microstructural characteristics of the brain lobes following radiotherapy (RT) for patients with nasopharyngeal carcinoma (NPC) at distinct times. Diffusion tensor imaging (DTI) and 3D-T1-weighted imaging was performed in 70 age- and sex-matched subjects, 24 of whom were pre-treatment patients. The patients were divided into three groups, according to the time following completion of RT. Fractional anisotropy (FA) and gray matter (GM) volume were determined. The DTI data were analyzed using tract-based spatial statistics and the GM volume was analyzed using voxel-based morphometry (VBM). Compared with the pre-RT group, the mean FA values in the left parietal lobe white matter (WM) and right cerebellum decreased significantly in the post-RT 0-6 month group (P<0.05). In addition, the mean FA values in the right parietal lobe WM decreased significantly in the post-RT 6-12 month group (P<0.05), compared with the pre-RT group. The FA level in the right temporal lobe remained significantly decreased, compared with that in the pre-RT group (P<0.05) for 1 year after RT. Furthermore, compared with pre-RT group, the GM volume in the bilateral frontal lobe, right occipital lobe, left parietal lobe, right temporal lobe and left cerebellum decreased significantly in the post-RT 0-6 month group (P<0.05), and in the bilateral temporal lobe, parietal lobe, right frontal lobe and left cerebellum, the GM volume decreased significantly in the post-RT 6-12 month group (P<0.05). The GM volume in the right temporal lobe, bilateral frontal lobe and bilateral cerebellum remained significantly decreased compared with that in the pre-RT group (P<0.05) for 1 year after RT. A combination of DTI and VBM may be used to determine radiation-induced brain injury in patients treated for NPC.

Provocation of symmetry/ordering symptoms in Anorexia nervosa: a functional neuroimaging study.

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Suda, Masashi; Brooks, Samantha J; Giampietro, Vincent; Uher, Rudolf; Mataix-Cols, David; Brammer, Michael J; Williams, Steven C R; Treasure, Janet; Campbell, Iain C

2014-01-01

Anorexia nervosa (AN), obsessive-compulsive disorder (OCD), and obsessive-compulsive personality disorder (OCPD) are often co-morbid; however, the aetiology of such co-morbidity has not been well investigated. This study examined brain activation in women with AN and in healthy control (HC) women during the provocation of symmetry/ordering-related anxiety. During provocation, patients with AN showed more anxiety compared to HCs, which was correlated with the severity of symmetry/ordering symptoms. Activation in the right parietal lobe and right prefrontal cortex (rPFC) in response to provocation was reduced in the AN group compared with the HC group. The reduced right parietal activation observed in the AN group is consistent with parietal lobe involvement in visuospatial cognition and with studies of OCD reporting an association between structural abnormalities in this region and the severity of 'ordering' symptoms. Reduced rPFC activation in response to symmetry/ordering provocation has similarities with some, but not all, data collected from patients with AN who were exposed to images of food and bodies. Furthermore, the combination of data from the AN and HC groups showed that rPFC activation during symptom provocation was inversely correlated with the severity of symmetry/ordering symptoms. These data suggest that individuals with AN have a diminished ability to cognitively deal with illness-associated symptoms of provocation. Furthermore, our data also suggest that symptom provocation can progressively overload attempts by the rPFC to exert cognitive control. These findings are discussed in the context of the current neurobiological models of AN.

Provocation of symmetry/ordering symptoms in Anorexia nervosa: a functional neuroimaging study.

Directory of Open Access Journals (Sweden)

Masashi Suda

Full Text Available Anorexia nervosa (AN, obsessive-compulsive disorder (OCD, and obsessive-compulsive personality disorder (OCPD are often co-morbid; however, the aetiology of such co-morbidity has not been well investigated. This study examined brain activation in women with AN and in healthy control (HC women during the provocation of symmetry/ordering-related anxiety. During provocation, patients with AN showed more anxiety compared to HCs, which was correlated with the severity of symmetry/ordering symptoms. Activation in the right parietal lobe and right prefrontal cortex (rPFC in response to provocation was reduced in the AN group compared with the HC group. The reduced right parietal activation observed in the AN group is consistent with parietal lobe involvement in visuospatial cognition and with studies of OCD reporting an association between structural abnormalities in this region and the severity of 'ordering' symptoms. Reduced rPFC activation in response to symmetry/ordering provocation has similarities with some, but not all, data collected from patients with AN who were exposed to images of food and bodies. Furthermore, the combination of data from the AN and HC groups showed that rPFC activation during symptom provocation was inversely correlated with the severity of symmetry/ordering symptoms. These data suggest that individuals with AN have a diminished ability to cognitively deal with illness-associated symptoms of provocation. Furthermore, our data also suggest that symptom provocation can progressively overload attempts by the rPFC to exert cognitive control. These findings are discussed in the context of the current neurobiological models of AN.

Widespread temporo-occipital lobe dysfunction in amyotrophic lateral sclerosis.

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Loewe, Kristian; Machts, Judith; Kaufmann, Jörn; Petri, Susanne; Heinze, Hans-Jochen; Borgelt, Christian; Harris, Joseph Allen; Vielhaber, Stefan; Schoenfeld, Mircea Ariel

2017-01-09

Recent studies suggest that amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) lie on a single clinical continuum. However, previous neuroimaging studies have found only limited involvement of temporal lobe regions in ALS. To better delineate possible temporal lobe involvement in ALS, the present study aimed to examine changes in functional connectivity across the whole brain, particularly with regard to extra-motor regions, in a group of 64 non-demented ALS patients and 38 healthy controls. To assess between-group differences in connectivity, we computed edge-level statistics across subject-specific graphs derived from resting-state functional MRI data. In addition to expected ALS-related decreases in functional connectivity in motor-related areas, we observed extensive changes in connectivity across the temporo-occipital cortex. Although ALS patients with comorbid FTD were deliberately excluded from this study, the pattern of connectivity alterations closely resembles patterns of cerebral degeneration typically seen in FTD. This evidence for subclinical temporal dysfunction supports the idea of a common pathology in ALS and FTD.

Functional and structural correlates of motor speed in the cerebellar anterior lobe.

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Uwe Wenzel

Full Text Available In athletics, motor performance is determined by different abilities such as technique, endurance, strength and speed. Based on animal studies, motor speed is thought to be encoded in the basal ganglia, sensorimotor cortex and the cerebellum. The question arises whether there is a unique structural feature in the human brain, which allows "power athletes" to perform a simple foot movement significantly faster than "endurance athletes". We acquired structural and functional brain imaging data from 32 track-and-field athletes. The study comprised of 16 "power athletes" requiring high speed foot movements (sprinters, jumpers, throwers and 16 endurance athletes (distance runners which in contrast do not require as high speed foot movements. Functional magnetic resonance imaging (fMRI was used to identify speed specific regions of interest in the brain during fast and slow foot movements. Anatomical MRI scans were performed to assess structural grey matter volume differences between athletes groups (voxel based morphometry. We tested maximum movement velocity of plantarflexion (PF-Vmax and acquired electromyographical activity of the lateral and medial gastrocnemius muscle. Behaviourally, a significant difference between the two groups of athletes was noted in PF-Vmax and fMRI indicates that fast plantarflexions are accompanied by increased activity in the cerebellar anterior lobe. The same region indicates increased grey matter volume for the power athletes compared to the endurance counterparts. Our results suggest that speed-specific neuro-functional and -structural differences exist between power and endurance athletes in the peripheral and central nervous system.

Accelerating regional atrophy rates in the progression from normal aging to Alzheimer's disease

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Sluimer, Jasper D. [VU University Medical Centre, Department of Diagnostic Radiology, Amsterdam (Netherlands); VU University Medical Centre, Alzheimer Centre, Amsterdam (Netherlands); VU University Medical Centre, Image Analysis Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Diagnostic Radiology and Alzheimer Centre, PO Box 7057, Amsterdam (Netherlands); Flier, Wiesje M. van der; Scheltens, Philip [VU University Medical Centre, Alzheimer Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Neurology, Amsterdam (Netherlands); Karas, Giorgos B.; Barkhof, Frederik [VU University Medical Centre, Department of Diagnostic Radiology, Amsterdam (Netherlands); VU University Medical Centre, Alzheimer Centre, Amsterdam (Netherlands); VU University Medical Centre, Image Analysis Centre, Amsterdam (Netherlands); Schijndel, Ronald van [VU University Medical Centre, Image Analysis Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Informatics, Amsterdam (Netherlands); Barnes, Josephine; Boyes, Richard G. [UCL, Institute of Neurology, Dementia Research Centre, London (United Kingdom); Cover, Keith S. [VU University Medical Centre, Department of Physics and Medical Technology, Amsterdam (Netherlands); Olabarriaga, Silvia D. [University of Amsterdam, Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, Amsterdam (Netherlands); Fox, Nick C. [VU University Medical Centre, Department of Neurology, Amsterdam (Netherlands); UCL, Institute of Neurology, Dementia Research Centre, London (United Kingdom); Vrenken, Hugo [VU University Medical Centre, Alzheimer Centre, Amsterdam (Netherlands); VU University Medical Centre, Image Analysis Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Physics and Medical Technology, Amsterdam (Netherlands)

2009-12-15

We investigated progression of atrophy in vivo, in Alzheimer's disease (AD), and mild cognitive impairment (MCI). We included 64 patients with AD, 44 with MCI and 34 controls with serial MRI examinations (interval 1.8 {+-} 0.7 years). A nonlinear registration algorithm (fluid) was used to calculate atrophy rates in six regions: frontal, medial temporal, temporal (extramedial), parietal, occipital lobes and insular cortex. In MCI, the highest atrophy rate was observed in the medial temporal lobe, comparable with AD. AD patients showed even higher atrophy rates in the extramedial temporal lobe. Additionally, atrophy rates in frontal, parietal and occipital lobes were increased. Cox proportional hazard models showed that all regional atrophy rates predicted conversion to AD. Hazard ratios varied between 2.6 (95% confidence interval (CI) = 1.1-6.2) for occipital atrophy and 15.8 (95% CI = 3.5-71.8) for medial temporal lobe atrophy. In conclusion, atrophy spreads through the brain with development of AD. MCI is marked by temporal lobe atrophy. In AD, atrophy rate in the extramedial temporal lobe was even higher. Moreover, atrophy rates also accelerated in parietal, frontal, insular and occipital lobes. Finally, in nondemented elderly, medial temporal lobe atrophy was most predictive of progression to AD, demonstrating the involvement of this region in the development of AD. (orig.)

Accelerating regional atrophy rates in the progression from normal aging to Alzheimer's disease

International Nuclear Information System (INIS)

Sluimer, Jasper D.; Flier, Wiesje M. van der; Scheltens, Philip; Karas, Giorgos B.; Barkhof, Frederik; Schijndel, Ronald van; Barnes, Josephine; Boyes, Richard G.; Cover, Keith S.; Olabarriaga, Silvia D.; Fox, Nick C.; Vrenken, Hugo

2009-01-01

We investigated progression of atrophy in vivo, in Alzheimer's disease (AD), and mild cognitive impairment (MCI). We included 64 patients with AD, 44 with MCI and 34 controls with serial MRI examinations (interval 1.8 ± 0.7 years). A nonlinear registration algorithm (fluid) was used to calculate atrophy rates in six regions: frontal, medial temporal, temporal (extramedial), parietal, occipital lobes and insular cortex. In MCI, the highest atrophy rate was observed in the medial temporal lobe, comparable with AD. AD patients showed even higher atrophy rates in the extramedial temporal lobe. Additionally, atrophy rates in frontal, parietal and occipital lobes were increased. Cox proportional hazard models showed that all regional atrophy rates predicted conversion to AD. Hazard ratios varied between 2.6 (95% confidence interval (CI) = 1.1-6.2) for occipital atrophy and 15.8 (95% CI = 3.5-71.8) for medial temporal lobe atrophy. In conclusion, atrophy spreads through the brain with development of AD. MCI is marked by temporal lobe atrophy. In AD, atrophy rate in the extramedial temporal lobe was even higher. Moreover, atrophy rates also accelerated in parietal, frontal, insular and occipital lobes. Finally, in nondemented elderly, medial temporal lobe atrophy was most predictive of progression to AD, demonstrating the involvement of this region in the development of AD. (orig.)

A functional MRI study of language networks in left medial temporal lobe epilepsy

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Yu Aihong, E-mail: yuaihong163@tom.com [Department of Radiology, the 4th Medical College of Peking University, Beijing Jishuitan Hospital, Beijing 100035 (China); Wang Xiaoyi; Xu Guoqing [Beijing Normal University, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing 100875 (China); Li Yongjie [Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053 (China); Qin Wen; Li Kuncheng [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences (China); Wang, Yuping [Department of Neurology, Xuanwu Hospital, Capital University of Medical Sciences (China)

2011-11-15

Purpose: The purpose of this study was to investigate the abnormality of language networks in left medial temporal lobe epilepsy (MTLE) using fMRI. Materials and methods: Eight patients with left MTLE and 15 healthy subjects were evaluated. An auditory semantic judgment (AJ) paradigm was used. The fMRI data were collected on a 3T MR system and analyzed by AFNI (analysis of functional neuroimages) to generate the activation map. Results: Behavioral data showed that the reaction time of the left MTLE patients was significantly longer than that of controls on the AJ task (t = -3.396, P < 0.05). The left MTLE patients also exhibited diffusively decreased activation in the AJ task. Right hemisphere dominance of Broca's and Wernicke's areas was demonstrated in left MTLE patients. Conclusions: Long-term activation of spikes in left MTLE patients results in language impairment, which is associated with an abnormality of the brain neural network.

A functional MRI study of language networks in left medial temporal lobe epilepsy

International Nuclear Information System (INIS)

Yu Aihong; Wang Xiaoyi; Xu Guoqing; Li Yongjie; Qin Wen; Li Kuncheng; Wang, Yuping

2011-01-01

Purpose: The purpose of this study was to investigate the abnormality of language networks in left medial temporal lobe epilepsy (MTLE) using fMRI. Materials and methods: Eight patients with left MTLE and 15 healthy subjects were evaluated. An auditory semantic judgment (AJ) paradigm was used. The fMRI data were collected on a 3T MR system and analyzed by AFNI (analysis of functional neuroimages) to generate the activation map. Results: Behavioral data showed that the reaction time of the left MTLE patients was significantly longer than that of controls on the AJ task (t = -3.396, P < 0.05). The left MTLE patients also exhibited diffusively decreased activation in the AJ task. Right hemisphere dominance of Broca's and Wernicke's areas was demonstrated in left MTLE patients. Conclusions: Long-term activation of spikes in left MTLE patients results in language impairment, which is associated with an abnormality of the brain neural network.

Brain SPECT imaging in temporal lobe epilepsy

International Nuclear Information System (INIS)

Krausz, Y.; Yaffe, S.; Atlan, H.; Cohen, D.; Konstantini, S.; Meiner, Z.

1991-01-01

Temporal lobe epilepsy is diagnosed by clinical symptoms and signs and by localization of an epileptogenic focus. A brain SPECT study of two patients with temporal lobe epilepsy, using 99m Tc-HMPAO, was used to demonstrate a perfusion abnormality in the temporal lobe, while brain CT and MRI were non-contributory. The electroencephalogram, though abnormal, did not localize the diseased area. The potential role of the SPECT study in diagnosis and localization of temporal lobe epilepsy is discussed. (orig.)

An fMRI study of mesial temporal lobe epilepsy with different pathological basis using amplitude of low-frequency fluctuation analysis

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Wei WEI

2014-12-01

Full Text Available Objective To study the distinction of abnormal brain activity in mesial temporal lobe epilepsy (mTLE with hippocampal sclerosis (HS or other pathogical basis, and to discuss their underlying pathophysiological mechanism in mTLE.  Methods Thirty mTLE patients with unilateral hippocampal sclerosis (mTLE-HS and 30 mTLE patients with occupying lesion in unilateral temporal lobe (mTLE-OL were investigated by comparing with 30 age- and sex-matched healthy subjects. MRI data were collected using a Siemens 3.0T scanner, and all of the participants were studied using amplitude of low-frequency fluctuation (ALFF analysis of resting state fMRI. A cost-function modification was used for image preprocessing, then the difference of extratemporal mALFF changes between the two groups of mTLE patients were analyzed with two-sample t test, and the correlation between mALFF and epilepsy duration of mTLE were also investigated.  Results In the resting state, mTLE-HS patients and mTLE-OL patients all showed significant changes in mALFF in extratemporal structures, but the distribution patterns of changes in brain were different. Compared with mTLE-HS, the mTLE-OL patients showed increased mALFF in bilateral inferior parietal lobes, precuneus, angular gyrus, middle and posterior cingulate gyrus and contralateral middle temporal gyrus, while mALFF reducing was observed in contralateral postcentral gyrus, bilateral middle occipital gyrus and cerebellum (P < 0.05, AlphaSim corrected, that is to say, the default mode network (DMN in mTLE-HS were inhibited more seriously than in mTLE-OL patients. Correlation analysis showed that no significant correlation was found between mALFF and epilepsy duration in mTLE-HS patients; mALFF in bilateral middle and posterior cingulate gyrus was positively correlated with epilepsy duration in mTLE-OL patients (r = 0.687, P = 0.000, while mALFF in bilateral anterior cingulate gyrus was negatively correlated with epilepsy duration (r

Ecdysone-dependent and ecdysone-independent programmed cell death in the developing optic lobe of Drosophila.

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Hara, Yusuke; Hirai, Keiichiro; Togane, Yu; Akagawa, Hiromi; Iwabuchi, Kikuo; Tsujimura, Hidenobu

2013-02-01

The adult optic lobe of Drosophila develops from the primordium during metamorphosis from mid-3rd larval stage to adult. Many cells die during development of the optic lobe with a peak of the number of dying cells at 24 h after puparium formation (h APF). Dying cells were observed in spatio-temporal specific clusters. Here, we analyzed the function of a component of the insect steroid hormone receptor, EcR, in this cell death. We examined expression patterns of two EcR isoforms, EcR-A and EcR-B1, in the optic lobe. Expression of each isoform altered during development in isoform-specific manner. EcR-B1 was not expressed in optic lobe neurons from 0 to 6h APF, but was expressed between 9 and 48 h APF and then disappeared by 60 h APF. In each cortex, its expression was stronger in older glia-ensheathed neurons than in younger ones. EcR-B1 was also expressed in some types of glia. EcR-A was expressed in optic lobe neurons and many types of glia from 0 to 60 h APF in a different pattern from EcR-B1. Then, we genetically analyzed EcR function in the optic lobe cell death. At 0 h APF, the optic lobe cell death was independent of any EcR isoforms. In contrast, EcR-B1 was required for most optic lobe cell death after 24 h APF. It was suggested that cell death cell-autonomously required EcR-B1 expressed after puparium formation. βFTZ-F1 was also involved in cell death in many dying-cell clusters, but not in some of them at 24 h APF. Altogether, the optic lobe cell death occurred in ecdysone-independent manner at prepupal stage and ecdysone-dependent manner after 24 h APF. The acquisition of ecdysone-dependence was not directly correlated with the initiation or increase of EcR-B1 expression. Copyright © 2012 Elsevier Inc. All rights reserved.

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.

[Analysis of the Characteristics of Infantile Small World Neural Network Node Properties Correlated with the Influencing Factors].

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Qu, Haibo; Lu, Su; Zhang, Wenjing; Xiao, Yuan; Ning, Gang; Sun, Huaiqiang

2016-10-01

We applied resting-state functional magnetic resonance imaging(rfMRI)combined with graph theory to analyze 90 regions of the infantile small world neural network of the whole brain.We tried to get the following two points clear:1 whether the parameters of the node property of the infantile small world neural network are correlated with the level of infantile intelligence development;2 whether the parameters of the infantile small world neural network are correlated with the children’s baseline parameters,i.e.,the demographic parameters such as gender,age,parents’ education level,etc.Twelve cases of healthy infants were included in the investigation(9males and 3females with the average age of 33.42±8.42 months.)We then evaluated the level of infantile intelligence of all the cases and graded by Gesell Development Scale Test.We used a Siemens 3.0T Trio imaging system to perform resting-state(rs)EPI scans,and collected the BOLD functional Magnetic Resonance Imaging(fMRI)data.We performed the data processing with Statistical Parametric Mapping 5(SPM5)based on Matlab environment.Furthermore,we got the attributes of the whole brain small world and node attributes of 90 encephalic regions of templates of Anatomatic Automatic Labeling(ALL).At last,we carried out correlation study between the above-mentioned attitudes,intelligence scale parameters and demographic data.The results showed that many node attributes of small world neural network were closely correlated with intelligence scale parameters.Betweeness was mainly centered in thalamus,superior frontal gyrus,and occipital lobe(negative correlation).The r value of superior occipital gyrus associated with the individual and social intelligent scale was-0.729(P=0.007);degree was mainly centered in amygdaloid nucleus,superior frontal gyrus,and inferior parietal gyrus(positive correlation).The r value of inferior parietal gyrus associated with the gross motor intelligent scale was 0.725(P=0.008);efficiency was mainly

Visual perception and memory systems: from cortex to medial temporal lobe.

Science.gov (United States)

Khan, Zafar U; Martín-Montañez, Elisa; Baxter, Mark G

2011-05-01

Visual perception and memory are the most important components of vision processing in the brain. It was thought that the perceptual aspect of a visual stimulus occurs in visual cortical areas and that this serves as the substrate for the formation of visual memory in a distinct part of the brain called the medial temporal lobe. However, current evidence indicates that there is no functional separation of areas. Entire visual cortical pathways and connecting medial temporal lobe are important for both perception and visual memory. Though some aspects of this view are debated, evidence from both sides will be explored here. In this review, we will discuss the anatomical and functional architecture of the entire system and the implications of these structures in visual perception and memory.

Source Monitoring 15 Years Later: What Have We Learned from fMRI about the Neural Mechanisms of Source Memory?

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Mitchell, Karen J.; Johnson, Marcia K.

2009-01-01

Focusing primarily on functional magnetic resonance imaging (fMRI), this article reviews evidence regarding the roles of subregions of the medial temporal lobes, prefrontal cortex, posterior representational areas, and parietal cortex in source memory. In addition to evidence from standard episodic memory tasks assessing accuracy for neutral…

A segmentectomy of the right upper lobe has an advantage over a right upper lobectomy regarding the preservation of the functional volume of the right middle lobe. Analysis by perfusion single-photon emission computed tomography/computed tomography

International Nuclear Information System (INIS)

Yoshimoto, Kentaro; Nomori, Hiroaki; Mori, Takeshi; Ohba, Yasuomi; Shibata, Hidekatsu; Tashiro, Kuniyuki; Shiraishi, Shinya; Kobayashi, Toshiaki

2010-01-01

To evaluate the advantages of a segmentectomy of the right upper lobe (RUL) over a right upper (RU) lobectomy regarding the preservation of the functional volume of the right middle lobe (RML), the postoperative forced expiratory volume in one second (FEV 1 ) of the RML was compared between an RU lobectomy and an RUL segmentectomy, by using a coregistered perfusion single-photon emission computed tomography and computed tomography (SPECT/CT). The pulmonary function tests and perfusion SPECT/CT were conducted before and after surgery (RU lobectomy: 7; RUL segmentectomy: 13). The FEV 1 of the RML before and after surgery was calculated from the data of the pulmonary function test and SPECT/CT. In the RU lobectomy group, the percentage change of FEV 1 was 71%±12%, which was significantly lower in comparison to 92%±9% in the RUL segmentectomy group (P=0.001). In the lobectomy group, the preoperative FEV 1 of the RML was 0.17±0.101 which decreased significantly to 0.06±0.061 after surgery (P=0.009). In the segmentectomy group, FEV 1 of the RML before and after the surgery were 0.23±0.101 and 0.20±0.111, of which the difference was not significant. An RUL segmentectomy has an advantage over an RU lobectomy regarding the preservation of pulmonary function, due to a greater preservation of not only the lung tissue, but also the FEV 1 of the RML. (author)

Hepatocellular carcinoma in Riedel's lobe.

Science.gov (United States)

Zamfir, R; Braşoveanu, V; Boroş, M; Herlea, V; Popescu, I

2008-01-01

We present a rare case of 65-year female with right abdominal mass and abdominal discomfort; a combination of Doppler ultrasonography, computed tomography and laparotomy was utilized to make a diagnosis of tumoral Riedel's lobe. In our case, laparotomy with resection of Riedel's lobe was the proper therapeutical solution.

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

Science.gov (United States)

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

Reorganization of Language Areas in Patient with a Frontal Lobe Low Grade Glioma – fMRI Case Study

International Nuclear Information System (INIS)

Kośla, Katarzyna; Bryszewski, Bartosz; Jaskólski, Dariusz; Błasiak-Kołacińska, Nina; Stefańczyk, Ludomir; Majos, Agata

2015-01-01

Functional magnetic resonance (fMRI) studies results in case of an adult patient with low grade glioma (LGG) in dominant hemisphere suggest brain plasticity process with acquisition of language functions by the non-dominant hemisphere speech regions. A 36-years old right-handed woman was admitted to the Department of Neurosurgery for surgical treatment of brain tumor. An MRI examination revealed a pathological mass in the left frontal lobe, in close topographical relationship to the Broca’s area. A left fronto-parietal craniotomy was performed, with an intraoperative awake language mapping procedure. A total resection of the pathological mass was achieved. The tumor was examined histologically as LGG. In the follow-up MRI exam 32 months after the operation a tumor recurrence was suggested. The fMRI exams performed preoperative and 3, 32 and 41 months after the operation showed changes in language regions activation patterns, with a progressive right-sided activation of Broca’s and Wernicke’s areas. Pre- and postoperative cognitive evaluation by a neuropsychologist did not detect any language impairment. We present a running process of reorganization of language areas in a patient after brain tumor resection, from strong left-sided to symmetrical lateralization. 1. FMRI results in comparison with the psychological status of the patient proved contribution of functional reorganization to the preservation of language performance. 2. A slow growing LGG as well as the recurrence of the tumor near the left Broca’s area might be the factors leading to reorganization of language-related areas by recruiting the right hemisphe

Deployment Instabilities of Lobed-Pumpkin Balloon

Science.gov (United States)

Nakashino, Kyoichi

A lobed-pumpkin balloon, currently being developed in ISAS/JAXA as well as in NASA, is a promising vehicle for long duration scientific observations in the stratosphere. Recent ground and flight experiments, however, have revealed that the balloon has deployment instabilities under certain conditions. In order to overcome the instability problems, a next generation SPB called 'tawara' type balloon has been proposed, in which an additional cylindrical part is appended to the standard lobed-pumpkin balloon. The present study investigates the deployment stability of tawara type SPB in comparison to that of standard lobed-pumpkin SPB through eigenvalue analysis on the basis of finite element methods. Our numerical results show that tawara type SPB enjoys excellent deployment performance over the standard lobed-pumpkin SPBs.

The Pivotal Role of the Parieto-Occipital Lobe in Card Game-Induced Reflex Epilepsy: A Voxel-Based Morphometry Study.

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Park, Kang Min; Kim, Sung Eun; Lee, Byung In

2016-01-01

The pathogenesis of card game-induced reflex epilepsy has not been determined so far. The aim of this study was to evaluate structural abnormalities using voxel-based morphometry (VBM) analysis, which may give some clue about the pathogenesis in card game-induced reflex epilepsy. The 3 subjects were diagnosed with card game-induced reflex epilepsy. Evaluation involved a structured interview to obtain clinical information and brain MRI. In VBM analysis, Statistical Parametric Mapping 8 running on the MATLAB platform was employed to analyze the structural differences between patients with card game-induced reflex epilepsy and age- and sex-matched control subjects. The results of VBM analysis revealed that patients with card game-induced reflex epilepsy had significantly increased gray matter volume in the right occipital and parietal lobe. However, there were no structures with decreased gray matter volume in patients with card game-induced reflex epilepsy compared with control subjects. In addition, we found that the patients with card game-induced reflex epilepsy had onset of seizures in adulthood rather than in adolescence, and all of the patients were men. The parieto-occipital lobes might be partially involved in the neuronal network responsible for card game-induced reflex epilepsy. © 2016 S. Karger AG, Basel.

Brain mapping of epileptic activity in a case of idiopathic occipital lobe epilepsy (Panayiotopoulos syndrome).

Science.gov (United States)

Leal, Alberto J R; Nunes, Sofia; Martins, António; Secca, Mário Forjaz; Jordão, Constança

2007-06-01

The Panayiotopoulos type of occipital lobe epilepsy has generated great interest, but the particular brain areas involved in the peculiar seizure manifestations have not been established. We studied a patient with the syndrome, using high-resolution EEG and simultaneous EEG and functional magnetic resonance imaging (fMRI). Resolution of the scalp EEG was improved using a realistic spline Laplacian algorithm, and produced a complex distribution of current sinks and sources over the occipital lobe. The spike-related blood oxygen level dependent (BOLD) effect was multifocal, with clusters in lateral and inferior occipital lobe and lateral and anterior temporal lobe. We also performed regional dipole seeding in BOLD clusters to determine their relative contribution to generation of scalp spikes. The integrated model of the neurophysiologic and vascular data strongly suggests that the epileptic activity originates in the lateral occipital area, spreading to the occipital pole and lateral temporal lobe.

Pediatric frontal lobe epilepsy : white matter abnormalities and cognitive impairment

NARCIS (Netherlands)

Braakman, H.M.H.; Vaessen, M.J.; Jansen, J.F.A.; Debeij-van Hall, M.H.J.A.; Louw, de A.; Hofman, P.A.M.; Vles, J.S.H.; Aldenkamp, A.P.; Backes, W.H.

2014-01-01

Objectives: Cognitive impairment is frequent in children with frontal lobe epilepsy (FLE). Its etiology remains unknown. With diffusion tensor imaging, we have studied cerebral white matter properties and associations with cognitive functioning in children with FLE and healthy controls.

Reversible changes in brain glucose metabolism following thyroid function normalization in hyperthyroidism.

Science.gov (United States)

Miao, Q; Zhang, S; Guan, Y H; Ye, H Y; Zhang, Z Y; Zhang, Q Y; Xue, R D; Zeng, M F; Zuo, C T; Li, Y M

2011-01-01

Patients with hyperthyroidism frequently present with regional cerebral metabolic changes, but the consequences of endocrine-induced brain changes after thyroid function normalization are unclear. We hypothesized that the changes of regional cerebral glucose metabolism are related to thyroid hormone levels in patients with hyperthyroid, and some of these changes can be reversed with antithyroid therapy. Relative regional cerebral glucose metabolism was compared between 10 new-onset untreated patients with hyperthyroidism and 20 healthy control participants by using brain FDG-PET scans. Levels of emotional distress were evaluated by using the SAS and SDS. Patients were treated with methimazole. A follow-up PET scan was performed to assess metabolic changes of the brain when thyroid functions normalized. Compared with controls, patients exhibited lower activity in the limbic system, frontal lobes, and temporal lobes before antithyroid treatment. There were positive correlations between scores of depression and regional metabolism in the cingulate and paracentral lobule. The severity of depression and anxiety covaried negatively with pretreatment activity in the inferior temporal and inferior parietal gyri respectively. Compared with the hyperthyroid status, patients with normalized thyroid functions showed an increased metabolism in the left parahippocampal, fusiform, and right superior frontal gyri. The decrease in both FT3 and FT4 was associated with increased activity in the left parahippocampal and right superior frontal gyri. The changes of regional cerebral glucose metabolism are related to thyroid hormone levels in patients with hyperthyroidism, and some cerebral hypometabolism can be improved after antithyroid therapy.

Short-Term Memory for Space and Time Flexibly Recruit Complementary Sensory-Biased Frontal Lobe Attention Networks.

Science.gov (United States)

Michalka, Samantha W; Kong, Lingqiang; Rosen, Maya L; Shinn-Cunningham, Barbara G; Somers, David C

2015-08-19

The frontal lobes control wide-ranging cognitive functions; however, functional subdivisions of human frontal cortex are only coarsely mapped. Here, functional magnetic resonance imaging reveals two distinct visual-biased attention regions in lateral frontal cortex, superior precentral sulcus (sPCS) and inferior precentral sulcus (iPCS), anatomically interdigitated with two auditory-biased attention regions, transverse gyrus intersecting precentral sulcus (tgPCS) and caudal inferior frontal sulcus (cIFS). Intrinsic functional connectivity analysis demonstrates that sPCS and iPCS fall within a broad visual-attention network, while tgPCS and cIFS fall within a broad auditory-attention network. Interestingly, we observe that spatial and temporal short-term memory (STM), respectively, recruit visual and auditory attention networks in the frontal lobe, independent of sensory modality. These findings not only demonstrate that both sensory modality and information domain influence frontal lobe functional organization, they also demonstrate that spatial processing co-localizes with visual processing and that temporal processing co-localizes with auditory processing in lateral frontal cortex. Copyright © 2015 Elsevier Inc. All rights reserved.

Short-term memory for space and time flexibly recruit complementary sensory-biased frontal lobe attention networks

Science.gov (United States)

Michalka, Samantha W.; Kong, Lingqiang; Rosen, Maya L.; Shinn-Cunningham, Barbara G.; Somers, David C.

2015-01-01

Summary The frontal lobes control wide-ranging cognitive functions; however, functional subdivisions of human frontal cortex are only coarsely mapped. Here, functional magnetic resonance imaging reveals two distinct visual-biased attention regions in lateral frontal cortex, superior precentral sulcus (sPCS) and inferior precentral sulcus (iPCS), anatomically interdigitated with two auditory-biased attention regions, transverse gyrus intersecting precentral sulcus (tgPCS) and caudal inferior frontal sulcus (cIFS). Intrinsic functional connectivity analysis demonstrates that sPCS and iPCS fall within a broad visual-attention network, while tgPCS and cIFS fall within a broad auditory-attention network. Interestingly, we observe that spatial and temporal short-term memory (STM), respectively, recruit visual and auditory attention networks in the frontal lobe, independent of sensory modality. These findings not only demonstrate that both sensory modality and information domain influence frontal lobe functional organization, they also demonstrate that spatial processing co-localizes with visual processing and that temporal processing co-localizes with auditory processing in lateral frontal cortex. PMID:26291168

Comparing TMS perturbations to occipital and parietal cortices in concurrent TMS-fMRI studies-Methodological considerations

DEFF Research Database (Denmark)

Leitao, Joana; Thielscher, Axel; Tuennerhoff, Johannes

2017-01-01

the effect of transient perturbations on functional brain organization. This concurrent TMS-fMRI study applied TMS perturbation to occipital and parietal cortices with the aim to 'mimick' neglect and hemianopia. Based on the challenges and interpretational limitations of our own study we aim to provide...

Brain processing of visual sexual stimuli in healthy men: a functional magnetic resonance imaging study.

Science.gov (United States)

Mouras, Harold; Stoléru, Serge; Bittoun, Jacques; Glutron, Dominique; Pélégrini-Issac, Mélanie; Paradis, Anne-Lise; Burnod, Yves

2003-10-01

The brain plays a central role in sexual motivation. To identify cerebral areas whose activation was correlated with sexual desire, eight healthy male volunteers were studied with functional magnetic resonance imaging (fMRI). Visual stimuli were sexually stimulating photographs (S condition) and emotionally neutral photographs (N condition). Subjective responses pertaining to sexual desire were recorded after each condition. To image the entire brain, separate runs focused on the upper and the lower parts of the brain. Statistical Parametric Mapping was used for data analysis. Subjective ratings confirmed that sexual pictures effectively induced sexual arousal. In the S condition compared to the N condition, a group analysis conducted on the upper part of the brain demonstrated an increased signal in the parietal lobes (superior parietal lobules, left intraparietal sulcus, left inferior parietal lobule, and right postcentral gyrus), the right parietooccipital sulcus, the left superior occipital gyrus, and the precentral gyri. In addition, a decreased signal was recorded in the right posterior cingulate gyrus and the left precuneus. In individual analyses conducted on the lower part of the brain, an increased signal was found in the right and/or left middle occipital gyrus in seven subjects, and in the right and/or left fusiform gyrus in six subjects. In conclusion, fMRI allows to identify brain responses to visual sexual stimuli. Among activated regions in the S condition, parietal areas are known to be involved in attentional processes directed toward motivationally relevant stimuli, while frontal premotor areas have been implicated in motor preparation and motor imagery. Further work is needed to identify those specific features of the neural responses that distinguish sexual desire from other emotional and motivational states.

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...

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…

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

Science.gov (United States)

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.

posterior reversible encephalopathy syndrome (PRES)

African Journals Online (AJOL)

signal intensity located in the bilateral frontal lobes, parietal lobes, temporal lobes and occipital lobes. (arrows); B and C, T2WI and FLAIR sequence, respectively, both of which show hyperintense signals in the same positions indicated by arrows; D, DWI shows slightly increased signals in the frontal lobes and isointense ...

Dissociation of writing processes: functional magnetic resonance imaging during writing of Japanese ideographic characters.

Science.gov (United States)

Matsuo, K; Nakai, T; Kato, C; Moriya, T; Isoda, H; Takehara, Y; Sakahara, H

2000-06-01

Dissociation between copying letters and writing to dictation has been reported in the clinical neuropsychological literature. Functional magnetic resonance imaging (fMRI) was conducted in normal volunteers to detect the neurofunctional differences between 'copying Kanji', the Japanese ideographic characters, and 'writing Kanji corresponding to phonological information'. Four tasks were conducted: the copying-Kanji task, the writing-Kanji-corresponding-to-phonogram task, the Kanji-grapheme-puzzle task, and the control task. The right superior parietal lobule was extensively activated during the copying-Kanji task (a model of the copying letters process) and the Kanji-grapheme-puzzle task. These observations suggested that this area was involved in referring the visual stimuli closely related to the ongoing handwriting movements. On the other hand, Broca's area, which is crucial for language production, was extensively activated during the writing-Kanji-corresponding-to-phonogram task (a model of the writing-to-dictation process). The Kanji-grapheme-puzzle task activated the bilateral border portions between the inferior parietal lobule and the occipital lobe, the left premotor area, and the bilateral supplementary motor area (SMA). Since the Kanji-grapheme-puzzle task involved manipulospatial characteristics, these results suggested cooperation between visuospatial and motor executive functions, which may be extensively utilized in demanding visual language processing. The neurofunctional difference between 'copying Kanji' and 'writing Kanji corresponding to phonogram' was efficiently demonstrated by this fMRI experiment.

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.

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

Bipolar affective disorders: Assessment of functional brain changes by means of Tc99m HMPAO neurospect