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Sample records for superior parietal damage

  1. Impaired speech repetition and left parietal lobe damage

    National Research Council Canada - National Science Library

    Fridriksson, Julius; Kjartansson, Olafur; Morgan, Paul S; Hjaltason, Haukur; Magnusdottir, Sigridur; Bonilha, Leonardo; Rorden, Christopher

    2010-01-01

    .... However, perfusion-weighted MRI revealed that tissue dysfunction, in the form of either frank damage or hypoperfusion, to the left inferior parietal lobe, rather than the underlying white matter...

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

    Science.gov (United States)

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

    2010-07-30

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

  3. Is the Posterior Parietal Lobe Involved in Working Memory Retrieval? Evidence from Patients with Bilateral Parietal Lobe Damage

    OpenAIRE

    Marian E Berryhill; Olson, Ingrid R.

    2008-01-01

    Neuroimaging evidence suggests that the parietal lobe has an important role in memory retrieval, yet neuropsychology is largely silent on this topic. Recently, we reported that unilateral parietal lobe damage impairs various forms of visual working memory when tested by old/new recognition. Here, we investigate whether parietal lobe working memory deficits are linked to problems at retrieval. We tested two patients with bilateral parietal lobe damage in a series of visual working memory tasks...

  4. Is the posterior parietal lobe involved in working memory retrieval? Evidence from patients with bilateral parietal lobe damage

    OpenAIRE

    Berryhill, M.E; Olson, I.R.

    2008-01-01

    Neuroimaging evidence suggests that the parietal lobe has an important role in memory retrieval, yet neuropsychology is largely silent on this topic. Recently, we reported that unilateral parietal lobe damage impairs various forms of visual working memory when tested by old/new recognition. Here, we investigate whether parietal lobe working memory deficits are linked to problems at retrieval. We tested two patients with bilateral parietal lobe damage in a series of visual working memory tasks...

  5. Is the posterior parietal lobe involved in working memory retrieval? Evidence from patients with bilateral parietal lobe damage.

    Science.gov (United States)

    Berryhill, Marian E; Olson, Ingrid R

    2008-01-01

    Neuroimaging evidence suggests that the parietal lobe has an important role in memory retrieval, yet neuropsychology is largely silent on this topic. Recently, we reported that unilateral parietal lobe damage impairs various forms of visual working memory when tested by old/new recognition. Here, we investigate whether parietal lobe working memory deficits are linked to problems at retrieval. We tested two patients with bilateral parietal lobe damage in a series of visual working memory tasks that probed recall and old/new recognition. Stimuli were presented sequentially and several stimulus categories were tested. The results of these experiments show that parietal lobe damage disproportionately impairs old/new recognition as compared to cued recall across stimulus categories. The observed performance dissociation suggests that the posterior parietal lobe plays a particularly vital role in working memory retrieval.

  6. Impaired speech repetition and left parietal lobe damage.

    Science.gov (United States)

    Fridriksson, Julius; Kjartansson, Olafur; Morgan, Paul S; Hjaltason, Haukur; Magnusdottir, Sigridur; Bonilha, Leonardo; Rorden, Christopher

    2010-08-18

    Patients with left hemisphere damage and concomitant aphasia usually have difficulty repeating others' speech. Although impaired speech repetition, the primary symptom of conduction aphasia, has been associated with involvement of the left arcuate fasciculus, its specific lesion correlate remains elusive. This research examined speech repetition among 45 stroke patients who underwent aphasia testing and MRI examination. Based on lesion-behavior mapping, the primary structural damage most closely associated with impaired speech repetition was found in the posterior portion of the left arcuate fasciculus. However, perfusion-weighted MRI revealed that tissue dysfunction, in the form of either frank damage or hypoperfusion, to the left inferior parietal lobe, rather than the underlying white matter, was associated with impaired speech repetition. This latter result suggests that integrity of the left inferior parietal lobe is important for speech repetition and, as importantly, highlights the importance of examining cerebral perfusion for the purpose of lesion-behavior mapping in acute stroke.

  7. Neural correlates of superior intelligence: stronger recruitment of posterior parietal cortex.

    Science.gov (United States)

    Lee, Kun Ho; Choi, Yu Yong; Gray, Jeremy R; Cho, Sun Hee; Chae, Jeong-Ho; Lee, Seungheun; Kim, Kyungjin

    2006-01-15

    General intelligence (g) is a common factor in diverse cognitive abilities and a major influence on life outcomes. Neuroimaging studies in adults suggest that the lateral prefrontal and parietal cortices play a crucial role in related cognitive activities including fluid reasoning, the control of attention, and working memory. Here, we investigated the neural bases for intellectual giftedness (superior-g) in adolescents, using fMRI. The participants consisted of a superior-g group (n = 18, mean RAPM = 33.9 +/- 0.8, >99%) from the national academy for gifted adolescents and the control group (n = 18, mean RAPM = 22.8 +/- 1.6, 60%) from local high schools in Korea (mean age = 16.5 +/- 0.8). fMRI data were acquired while they performed two reasoning tasks with high and low g-loadings. In both groups, the high g-loaded tasks specifically increased regional activity in the bilateral fronto-parietal network including the lateral prefrontal, anterior cingulate, and posterior parietal cortices. However, the regional activations of the superior-g group were significantly stronger than those of the control group, especially in the posterior parietal cortex. Moreover, regression analysis revealed that activity of the superior and intraparietal cortices (BA 7/40) strongly covaried with individual differences in g (r = 0.71 to 0.81). A correlated vectors analysis implicated bilateral posterior parietal areas in g. These results suggest that superior-g may not be due to the recruitment of additional brain regions but to the functional facilitation of the fronto-parietal network particularly driven by the posterior parietal activation.

  8. Decoding the superior parietal lobule connections of the superior longitudinal fasciculus/arcuate fasciculus in the human brain.

    Science.gov (United States)

    Kamali, A; Sair, H I; Radmanesh, A; Hasan, K M

    2014-09-26

    The temporo-parietal (TP) white matter connections between the inferior parietal lobule and superior temporal gyrus as part of the superior longitudinal fasciculus/arcuate fasciculus (SLF/AF) or middle longitudinal fasciculus (MdLF) have been studied in prior diffusion tensor tractography (DTT) studies. However, few studies have been focusing on the higher TP connections of the superior parietal lobule with the temporal lobe. These higher TP connections have been shown to have a role in core processes such as attention, memory, emotions, and language. Our most recent study, for the first time, hinted to the possibility of a long white matter connection interconnecting the superior parietal lobule (SPL) with the posterior temporal lobe in human brain which we call the SLF/AF TP-SPL and for a shorter abbreviation, the TP-SPL. We decided to further investigate this white matter connection using fiber assignment by continuous tracking deterministic tractography and high spatial resolution diffusion tensor imaging on 3T. Five healthy right-handed men (age range 24-37 years) were studied. We delineated the SPL connections of the SLF/AF TP bilaterally in five normal adult human brains. Using a high resolution DTT technique, we demonstrate for the first time, the trajectory of a long fiber bundle connectivity between the SPL and posterior temporal lobe, called the SLF/AF TP-SPL (or the TP-SPL), bilaterally in five healthy adult human brains. We also demonstrate the trajectory of the vertically oriented posterior TP connections, interconnecting the inferior parietal lobule (IPL) with the posterior temporal lobe (TP-IPL) in relation to the TP-SPL, arcuate fasciculus and other major language pathways. In the current study, for the first time, we categorized the TP connections into the anterior and posterior connectivity groups and subcategorized each one into the SPL or IPL connections. Published by Elsevier Ltd.

  9. Left superior parietal cortex involvement in writing: integrating fMRI with lesion evidence.

    Science.gov (United States)

    Menon, V; Desmond, J E

    2001-10-01

    Writing is a uniquely human skill that we utilize nearly everyday. Lesion studies in patients with Gerstmann's syndrome have pointed to the parietal cortex as being critical for writing. Very little information is, however, available about the precise anatomical location of brain regions subserving writing in normal healthy individuals. In this study, we used functional magnetic resonance imaging (fMRI) to investigate parietal lobe function during writing to dictation. Significant clusters of activation were observed in left superior parietal lobe (SPL) and the dorsal aspects of the inferior parietal cortex (IPC) bordering the SPL. Localized clusters of activation were also observed in the left premotor cortex, sensorimotor cortex and supplementary motor area. No activation cluster was observed in the right hemisphere. These results clearly indicate that writing appears to be primarily organized in the language-dominant hemisphere. Further analysis revealed that within the parietal cortex, activation was significantly greater in the left SPL, compared to left IPC. Together with lesion studies, findings from the present study provide further evidence for the essential role of the left SPL in writing. Deficits to the precise left hemisphere parietal cortex regions identified in the present study may specifically underlie disorders of writing observed in Gerstmann's syndrome and apractic agraphia.

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

    Science.gov (United States)

    Klarborg, Brith; Skak Madsen, Kathrine; Vestergaard, Martin; Skimminge, Arnold; Jernigan, Terry L; Baaré, William F C

    2013-12-01

    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 (RTCV ). 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 anatomical regions-of-interest (ROIs) in the left hemisphere and mean global WM FA. When analyzed collectively, right hemisphere ROIs FA was significantly associated with d' independently of age. Follow-up analyses revealed that only FA of right SLF and the superior part of the right PC contributed significantly to this association. RTCV was significantly associated with right superior PC FA, but not with right SLF FA. Observed associations remained significant after controlling for FA of equivalent left hemisphere ROIs or global mean FA. In conclusion, better sustained attention performance was associated with higher FA of WM in regions connecting right frontal and parietal cortices. Further studies are needed to clarify to which extent these associations are driven by maturational processes, stable characteristics and/or experience.

  11. Visual processing of multiple elements in the dyslexic brain: evidence for a superior parietal dysfunction

    Directory of Open Access Journals (Sweden)

    Muriel Anne Lobier

    2014-07-01

    Full Text Available The visual attention (VA span deficit hypothesis of developmental dyslexia posits that impaired multiple element processing can be responsible for poor reading outcomes. In VA span impaired dyslexic children, poor performance on letter report tasks is associated with reduced parietal activations for multiple letter processing. While this hints towards a non-specific, attention-based dysfunction, it is still unclear whether reduced parietal activity generalizes to other types of stimuli. Furthermore, putative links between reduced parietal activity and reduced ventral occipito-temporal (vOT in dyslexia have yet to be explored. Using fMRI, we measured brain activity in 12 VA span impaired dyslexic adults and 12 adult skilled readers while they carried out a categorization task on single or multiple alphanumeric or non-alphanumeric characters. While healthy readers activated parietal areas more strongly for multiple than single element processing (right-sided for alphanumeric and bilateral for non-alphanumeric, similar stronger multiple element right parietal activations were absent for dyslexic participants. Contrasts between skilled and dyslexic readers revealed significantly reduced right superior parietal lobule (SPL activity for dyslexic readers regardless of stimuli type. Using a priori anatomically defined ROI, we showed that neural activity was reduced for dyslexic participants in both SPL and vOT bilaterally. Finally, we used multiple regressions to test whether SPL activity could predict vOT activity in each group. In the left hemisphere, SPL activity modulated vOT activity for both normal and dyslexic readers. In contrast, in the right hemisphere, SPL activity modulated vOT activity only for dyslexic readers. These results bring critical support to the visual attention interpretation of the VA Span deficit. In addition, they offer a new insight on how deficits in automatic vOT based word recognition could arise in developmental dyslexia.

  12. The Neuroanatomical Basis for Posterior Superior Parietal Lobule Control Lateralization of Visuospatial Attention.

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    Wu, Yan; Wang, Jiaojian; Zhang, Yun; Zheng, Dingchen; Zhang, Jinfeng; Rong, Menglin; Wu, Huawang; Wang, Yinyan; Zhou, Ke; Jiang, Tianzi

    2016-01-01

    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. Transcranial magnetic stimulation (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 (MFG), with the ipsilateral inferior frontal gyrus (IFG), 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.

  13. Functional Connectivity Between Superior Parietal Lobule and Primary Visual Cortex "at Rest" Predicts Visual Search Efficiency.

    Science.gov (United States)

    Bueichekú, Elisenda; Ventura-Campos, Noelia; Palomar-García, María-Ángeles; Miró-Padilla, Anna; Parcet, María-Antonia; Ávila, César

    2015-10-01

    Spatiotemporal activity that emerges spontaneously "at rest" has been proposed to reflect individual a priori biases in cognitive processing. This research focused on testing neurocognitive models of visual attention by studying the functional connectivity (FC) of the superior parietal lobule (SPL), given its central role in establishing priority maps during visual search tasks. Twenty-three human participants completed a functional magnetic resonance imaging session that featured a resting-state scan, followed by a visual search task based on the alphanumeric category effect. As expected, the behavioral results showed longer reaction times and more errors for the within-category (i.e., searching a target letter among letters) than the between-category search (i.e., searching a target letter among numbers). The within-category condition was related to greater activation of the superior and inferior parietal lobules, occipital cortex, inferior frontal cortex, dorsal anterior cingulate cortex, and the superior colliculus than the between-category search. The resting-state FC analysis of the SPL revealed a broad network that included connections with the inferotemporal cortex, dorsolateral prefrontal cortex, and dorsal frontal areas like the supplementary motor area and frontal eye field. Noteworthy, the regression analysis revealed that the more efficient participants in the visual search showed stronger FC between the SPL and areas of primary visual cortex (V1) related to the search task. We shed some light on how the SPL establishes a priority map of the environment during visual attention tasks and how FC is a valuable tool for assessing individual differences while performing cognitive tasks.

  14. Changes in Effective Connectivity of the Superior Parietal Lobe during Inhibition and Redirection of Eye Movements

    Science.gov (United States)

    Asscheman, Susanne J.; Thakkar, Katharine N.; Neggers, Sebastiaan F.W.

    2015-01-01

    Executive control is the ability to flexibly control behavior and is frequently studied with saccadic eye movements. Contrary to frontal oculomotor areas, the role of the superior parietal lobe (SPL) in the executive control of saccades remains unknown. To explore the role of SPL networks in saccade control, we performed a saccadic search-step task while acquiring functional magnetic resonance imaging data for 41 participants. Psychophysiological interaction analyses assessed task-related differences in the effective connectivity of SPL with other brain regions during the inhibition and redirection of saccades. Results indicate an increased coupling of SPL with frontal, posterior, and striatal oculomotor areas for redirected saccades versus visually guided saccades. Saccade inhibition versus unsuccessful inhibition revealed an increased coupling of SPL with dorsolateral prefrontal cortex and anterior cingulate cortex. We discuss how these findings relate to ongoing debates about the implementation of executive control and conclude that early attentional control and rapid updating of saccade goals are important signals for executive control. PMID:27147827

  15. Changes in Effective Connectivity of the Superior Parietal Lobe during Inhibition and Redirection of Eye Movements

    Directory of Open Access Journals (Sweden)

    Susanne J. Asscheman

    2015-01-01

    Full Text Available Executive control is the ability to flexibly control behavior and is frequently studied with saccadic eye movements. Contrary to frontal oculomotor areas, the role of the superior parietal lobe (SPL in the executive control of saccades remains unknown. To explore the role of SPL networks in saccade control, we performed a saccadic search-step task while acquiring functional magnetic resonance imaging data for 41 participants. Psychophysiological interaction analyses assessed task-related differences in the effective connectivity of SPL with other brain regions during the inhibition and redirection of saccades. Results indicate an increased coupling of SPL with frontal, posterior, and striatal oculomotor areas for redirected saccades versus visually guided saccades. Saccade inhibition versus unsuccessful inhibition revealed an increased coupling of SPL with dorsolateral prefrontal cortex and anterior cingulate cortex. We discuss how these findings relate to ongoing debates about the implementation of executive control and conclude that early attentional control and rapid updating of saccade goals are important signals for executive control.

  16. Changes in Effective Connectivity of the Superior Parietal Lobe during Inhibition and Redirection of Eye Movements.

    Science.gov (United States)

    Asscheman, Susanne J; Thakkar, Katharine N; Neggers, Sebastiaan F W

    2015-01-01

    Executive control is the ability to flexibly control behavior and is frequently studied with saccadic eye movements. Contrary to frontal oculomotor areas, the role of the superior parietal lobe (SPL) in the executive control of saccades remains unknown. To explore the role of SPL networks in saccade control, we performed a saccadic search-step task while acquiring functional magnetic resonance imaging data for 41 participants. Psychophysiological interaction analyses assessed task-related differences in the effective connectivity of SPL with other brain regions during the inhibition and redirection of saccades. Results indicate an increased coupling of SPL with frontal, posterior, and striatal oculomotor areas for redirected saccades versus visually guided saccades. Saccade inhibition versus unsuccessful inhibition revealed an increased coupling of SPL with dorsolateral prefrontal cortex and anterior cingulate cortex. We discuss how these findings relate to ongoing debates about the implementation of executive control and conclude that early attentional control and rapid updating of saccade goals are important signals for executive control.

  17. Impaired perception of mnemonic oldness, but not mnemonic newness, after parietal lobe damage.

    Science.gov (United States)

    Hower, Kylie H; Wixted, John; Berryhill, Marian E; Olson, Ingrid R

    2014-04-01

    In studies of episodic memory retrieval, recognition paradigms are known to elicit robust activations in the inferior parietal lobe. However, damage to this region does not produce severe deficits in episodic memory performance as indexed by typical accuracy measures. Rather, because problems with memory confidence are frequently reported, the observed deficits may be best described as "metamemory" or subjective memory deficits. Here, we further investigated the inferior parietal lobe's role in recognition memory as well as metamemory. We tested the hypothesis that the inferior parietal lobe gauges the perceived oldness of items, given several neuroimaging findings suggesting that a portion of the left inferior parietal lobe is sensitive to perceived oldness. We tested two patients with bilateral parietal lobe lesions and matched controls on an old/new recognition task. From these data we constructed receiver operating characteristic (ROC) curves by fitting the data with the unequal-variance signal-detection (UVSD) model. The results revealed no memory impairment in terms of patients' accuracy. However, patients exhibited lower hit rates and false alarms rates at high confidence levels. Further, patients and controls differed in how they set decision criteria for making recognition responses. Patients' decision criteria for "old" responses were shifted in a conservative fashion such that they were unwilling to endorse recognized target items with high levels of confidence. These findings provide constraints on models of inferior parietal lobe contributions to episodic memory retrieval. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Impaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage.

    Science.gov (United States)

    Snow, Jacqueline C; Miranda, Rodrigo R; Humphreys, Glyn W

    2013-01-01

    The parietal cortex is considered to be part of a network of brain areas that modulates competitive interactions between targets and irrelevant distracters in early visual cortex, however there is currently little causal evidence to support this in human observers. It is also unclear as to whether parietal influences on visual perception in humans are limited to the contralesional hemispace or whether a unilateral lesion affects visual sensitivity bilaterally. Here we examined visual sensitivity in two patients with spatial neglect and extinction arising primarily from left-parietal damage. We used a sensitive psychophysical task based on those previously used to demonstrate loss of stimulus selection after lesions to extrastriate cortex. Observers discriminated the orientation of a lateralized suprathreshold target grating that appeared alone or in the context of nearby salient disc distracters. For parietal patients, target sensitivity within both the contralesional and ipsilesional fields was compromised by the presence of distracters. Conversely, healthy matched controls were unaffected by distracters. These results indicate that parietal cortex damage can influence visual perception within both the ipsi- as well as the contralesional field. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. 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

    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......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...

  20. Anarchic hand with abnormal agency following right inferior parietal lobe damage: a case report.

    Science.gov (United States)

    Jenkinson, Paul M; Edelstyn, Nicola M J; Preston, Catherine; Ellis, Simon J

    2015-01-01

    Anarchic hand syndrome (AHS) is characterized by goal-directed movements performed without volitional control (agency). Different AHS subtypes have been identified; however, few studies have examined the posterior subtype. We report a case of AHS following right-hemisphere parietal damage, with left-sided somatosensory and proprioceptive impairment. Agency was examined for nonanarchic (volitional) movements performed using the anarchic hand. The patient experienced abnormal agency for movements whether motor intention and visual feedback were congruent or incongruent, but not when intention was absent (passive movement). Findings suggest a general disturbance of veridical motor awareness and agency in this case of parietal AHS.

  1. The role of left superior parietal lobe in male sexual behavior: dynamics of distinct components revealed by FMRI.

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    Cera, Nicoletta; Di Pierro, Ezio D; Sepede, Gianna; Gambi, Francesco; Perrucci, Mauro Gianni; Merla, Arcangelo; Tartaro, Armando; Del Gratta, Cosimo; Galatioto Paradiso, Giuseppe; Vicentini, Carlo; Romani, Gian Luca; Ferretti, Antonio

    2012-06-01

    Despite the interest for the brain correlates of male sexual arousal, few studies investigated neural mechanisms underlying psychogenic erectile dysfunction (ED). Although these studies showed several brain regions active in ED patients during visual erotic stimulation, the dynamics of inhibition of sexual response is still unclear. This study investigated the dynamics of brain regions involved in the psychogenic ED. Functional magnetic resonance imaging (fMRI) and simultaneous penile tumescence (PT) were used to study brain activity evoked in 17 outpatients with psychogenic ED and 19 healthy controls during visual erotic stimulation. Patterns of brain activation related to different phases of sexual response in the two groups were compared. Simultaneous recording of blood oxygen level-dependent fMRI responses and PT during visual erotic stimulation. During visual erotic stimuli, a larger activation was observed for the patient group in the left superior parietal lobe, ventromedial prefrontal cortex, and posterior cingulate cortex, whereas the control group showed larger activation in the right middle insula and dorsal anterior cingulate cortex and hippocampus. Moreover, the left superior parietal lobe showed a larger activation in patients than controls especially during the later stage of sexual response. Our results suggest that, among regions more active in patient group, the left superior parietal lobe plays a crucial role in inhibition of sexual response. Previous studies showed that left superior parietal lobe is involved in monitoring of internal body representation. The larger activation of this region in patients during later stages of sexual response suggests a high monitoring of the internal body representation, possibly affecting the behavioral response. These findings provide insight on brain mechanisms involved in psychogenic ED. © 2012 International Society for Sexual Medicine.

  2. Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception.

    Directory of Open Access Journals (Sweden)

    Marjolijn Hoekert

    Full Text Available In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms. Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction, revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become

  3. Sleep paralysis and "the bedroom intruder": the role of the right superior parietal, phantom pain and body image projection.

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    Jalal, Baland; Ramachandran, Vilayanur S

    2014-12-01

    Sleep paralysis (SP) is a common condition occurring either at sleep onset or sleep offset. During SP the sleeper experiences gross motor paralysis while the sensory system is clear. Hypnogogic and hypnopompic hallucinations are common during SP and may involve seeing, hearing, and sensing the presence of menacing intruders in one's bedroom. This "intruder" is often perceived as a shadowy humanoid figure. Supernatural accounts of this hallucinated intruder are common across cultures. In this paper, we postulate that a functional disturbance of the right parietal cortex explains the shadowy nocturnal bedroom intruder hallucination during SP. This hallucination may arise due to a disturbance in the multisensory processing of body and self at the temporoparietal junction. We specifically propose that this perceived intruder is the result of a hallucinated projection of the genetically "hard-wired" body image (homunculus), in the right parietal region; namely, the same circuits that dictate aesthetic and sexual preference of body morphology. One way to test this hypothesis would be to study clinical populations who may have genetically acquired "irregularities" in their internal hard-wired body image in the right superior parietal lobule (SPL); for example, individuals with apotemnophilia or anorexia nervosa. If such individuals experience SP (e.g., induced in a sleep lab), and they hallucinate this shadowy figure, one would predict that they would see humanoid shadows and shapes with body irregularities, mirroring their own internal body image morphology. If correct, our hypothesis will offer a neurological explanation for this nocturnal bedroom intruder that has been a source of controversy, and striking and implausible cultural interpretations throughout history. Indeed, if our proposed hypothesis is tested and corroborated, dissemination of such findings would provide great relief to SP experiencers worldwide and could potentially be used in a therapeutic context.

  4. A brain-computer interface based on self-regulation of gamma-oscillations in the superior parietal cortex

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    Grosse-Wentrup, Moritz; Schölkopf, Bernhard

    2014-10-01

    Objective. Brain-computer interface (BCI) systems are often based on motor- and/or sensory processes that are known to be impaired in late stages of amyotrophic lateral sclerosis (ALS). We propose a novel BCI designed for patients in late stages of ALS that only requires high-level cognitive processes to transmit information from the user to the BCI. Approach. We trained subjects via EEG-based neurofeedback to self-regulate the amplitude of gamma-oscillations in the superior parietal cortex (SPC). We argue that parietal gamma-oscillations are likely to be associated with high-level attentional processes, thereby providing a communication channel that does not rely on the integrity of sensory- and/or motor-pathways impaired in late stages of ALS. Main results. Healthy subjects quickly learned to self-regulate gamma-power in the SPC by alternating between states of focused attention and relaxed wakefulness, resulting in an average decoding accuracy of 70.2%. One locked-in ALS patient (ALS-FRS-R score of zero) achieved an average decoding accuracy significantly above chance-level though insufficient for communication (55.8%). Significance. Self-regulation of gamma-power in the SPC is a feasible paradigm for brain-computer interfacing and may be preserved in late stages of ALS. This provides a novel approach to testing whether completely locked-in ALS patients retain the capacity for goal-directed thinking.

  5. Reaching in depth: hand position dominates over binocular eye position in the rostral superior parietal lobule.

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    Ferraina, Stefano; Brunamonti, Emiliano; Giusti, Maria Assunta; Costa, Stefania; Genovesio, Aldo; Caminiti, Roberto

    2009-09-16

    Neural activity was recorded in area PE (dorsorostral part of Brodmann's area 5) of the posterior parietal cortex while monkeys performed arm reaching toward memorized targets located at different distances from the body. For any given distance, arm movements were performed while the animal kept binocular eye fixation constant. Under these conditions, the activity of a large proportion (36%) of neurons was modulated by reach distance during the memory period. By varying binocular eye position (vergence angle) and initial hand position, we found that the reaching-related activity of most neurons (61%) was influenced by changing the starting position of the hand, whereas that of a smaller, although substantial, population (13%) was influenced by changes of binocular eye position (i.e., by the angle of vergence). Furthermore, the modulation of the neural activity was better explained expressing the reach movement end-point, corresponding to the memorized target location, in terms of distance from the initial hand position, rather than from the body. These results suggest that the activity of neurons in area PE combines information about eye and hand position to encode target distance for reaching in depth predominantly in hand coordinates. This encoding mechanism is consistent with the position of PE in the functional gradient that characterizes the parieto-frontal network underlying reaching.

  6. Motor learning in individuals with autism spectrum disorder: activation in superior parietal lobule related to learning and repetitive behaviors.

    Science.gov (United States)

    Travers, Brittany G; Kana, Rajesh K; Klinger, Laura G; Klein, Christopher L; Klinger, Mark R

    2015-02-01

    Motor-linked implicit learning is the learning of a sequence of movements without conscious awareness. Although motor symptoms are frequently reported in individuals with autism spectrum disorder (ASD), recent behavioral studies have suggested that motor-linked implicit learning may be intact in ASD. The serial reaction time (SRT) task is one of the most common measures of motor-linked implicit learning. The present study used a 3T functional magnetic resonance imaging scanner to examine the behavioral and neural correlates of real-time motor sequence learning in adolescents and adults with ASD (n = 15) compared with age- and intelligence quotient-matched individuals with typical development (n = 15) during an SRT task. Behavioral results suggested less robust motor sequence learning in individuals with ASD. Group differences in brain activation suggested that individuals with ASD, relative to individuals with typical development, showed decreased activation in the right superior parietal lobule (SPL) and right precuneus (Brodmann areas 5 and 7, and extending into the intraparietal sulcus) during learning. Activation in these areas (and in areas such as the right putamen and right supramarginal gyrus) was found to be significantly related to behavioral learning in this task. Additionally, individuals with ASD who had more severe repetitive behavior/restricted interest symptoms demonstrated greater decreased activation in these regions during motor learning. In conjunction, these results suggest that the SPL may play an important role in motor learning and repetitive behavior in individuals with ASD.

  7. Evaluating the roles of the inferior frontal gyrus and superior parietal lobule in deductive reasoning: an rTMS study.

    Science.gov (United States)

    Tsujii, Takeo; Sakatani, Kaoru; Masuda, Sayako; Akiyama, Takekazu; Watanabe, Shigeru

    2011-09-15

    This study used off-line repetitive transcranial magnetic stimulation (rTMS) to examine the roles of the superior parietal lobule (SPL) and inferior frontal gyrus (IFG) in a deductive reasoning task. Subjects performed a categorical syllogistic reasoning task involving congruent, incongruent, and abstract trials. Twenty four subjects received magnetic stimulation to the SPL region prior to the task. In the other 24 subjects, TMS was administered to the IFG region before the task. Stimulation lasted for 10min, with an inter-pulse frequency of 1Hz. We found that bilateral SPL (Brodmann area (BA) 7) stimulation disrupted performance on abstract and incongruent reasoning. Left IFG (BA 45) stimulation impaired congruent reasoning performance while paradoxically facilitating incongruent reasoning performance. This resulted in the elimination of the belief-bias. In contrast, right IFG stimulation only impaired incongruent reasoning performance, thus enhancing the belief-bias effect. These findings are largely consistent with the dual-process theory of reasoning, which proposes the existence of two different human reasoning systems: a belief-based heuristic system; and a logic-based analytic system. The present findings suggest that the left language-related IFG (BA 45) may correspond to the heuristic system, while bilateral SPL may underlie the analytic system. The right IFG may play a role in blocking the belief-based heuristic system for solving incongruent reasoning trials. This study could offer an insight about functional roles of distributed brain systems in human deductive reasoning by utilizing the rTMS approach.

  8. 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

    Science.gov (United States)

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

    2013-01-01

    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. PMID:23686576

  9. Self-face recognition shares brain regions active during proprioceptive illusion in the right inferior fronto-parietal superior longitudinal fasciculus III network.

    Science.gov (United States)

    Morita, Tomoyo; Saito, Daisuke N; Ban, Midori; Shimada, Koji; Okamoto, Yuko; Kosaka, Hirotaka; Okazawa, Hidehiko; Asada, Minoru; Naito, Eiichi

    2017-04-21

    Proprioception is somatic sensation that allows us to sense and recognize position, posture, and their changes in our body parts. It pertains directly to oneself and may contribute to bodily awareness. Likewise, one's face is a symbol of oneself, so that visual self-face recognition directly contributes to the awareness of self as distinct from others. Recently, we showed that right-hemispheric dominant activity in the inferior fronto-parietal cortices, which are connected by the inferior branch of the superior longitudinal fasciculus (SLF III), is associated with proprioceptive illusion (awareness), in concert with sensorimotor activity. Herein, we tested the hypothesis that visual self-face recognition shares brain regions active during proprioceptive illusion in the right inferior fronto-parietal SLF III network. We scanned brain activity using functional magnetic resonance imaging while twenty-two right-handed healthy adults performed two tasks. One was a proprioceptive illusion task, where blindfolded participants experienced a proprioceptive illusion of right hand movement. The other was a visual self-face recognition task, where the participants judged whether an observed face was their own. We examined whether the self-face recognition and the proprioceptive illusion commonly activated the inferior fronto-parietal cortices connected by the SLF III in a right-hemispheric dominant manner. Despite the difference in sensory modality and in the body parts involved in the two tasks, both tasks activated the right inferior fronto-parietal cortices, which are likely connected by the SLF III, in a right-side dominant manner. Here we discuss possible roles for right inferior fronto-parietal activity in bodily awareness and self-awareness. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  10. The Left Superior Longitudinal Fasciculus within the Primary Sensory Area of Inferior Parietal Lobe Plays a Role in Dysgraphia of Kana Omission within Sentences

    Directory of Open Access Journals (Sweden)

    Nobusada Shinoura

    2012-01-01

    Full Text Available Functional neurological changes after surgery combined with diffusion tensor imaging (DTI tractography can directly provide evidence of anatomical localization of brain function. Using these techniques, a patient with dysgraphia before surgery was analyzed at our hospital in 2011. The patient showed omission of kana within sentences before surgery, which improved after surgery. The brain tumor was relatively small and was located within the primary sensory area (S1 of the inferior parietal lobe (IPL. DTI tractography before surgery revealed compression of the branch of the superior longitudinal fasciculus (SLF by the brain tumor. These results suggest that the left SLF within the S1 of IPL plays a role in the development of dysgraphia of kana omission within sentences.

  11. Fluid intelligence loss linked to restricted regions of damage within frontal and parietal cortex

    Science.gov (United States)

    Woolgar, Alexandra; Parr, Alice; Cusack, Rhodri; Thompson, Russell; Nimmo-Smith, Ian; Torralva, Teresa; Roca, Maria; Antoun, Nagui; Manes, Facundo; Duncan, John

    2010-01-01

    Tests of fluid intelligence predict success in a wide range of cognitive activities. Much uncertainty has surrounded brain lesions producing deficits in these tests, with standard group comparisons delivering no clear result. Based on findings from functional imaging, we propose that the uncertainty of lesion data may arise from the specificity and complexity of the relevant neural circuit. Fluid intelligence tests give a characteristic pattern of activity in posterolateral frontal, dorsomedial frontal, and midparietal cortex. To test the causal role of these regions, we examined fluid intelligence in 80 patients with focal cortical lesions. Damage to each of the proposed regions predicted fluid intelligence loss, whereas damage outside these regions was not predictive. The results suggest that coarse group comparisons (e.g., frontal vs. posterior) cannot show the neural underpinnings of fluid intelligence tests. Instead, deficits reflect the extent of damage to a restricted but complex brain circuit comprising specific regions within both frontal and posterior cortex. PMID:20679241

  12. Effect of the stimulus frequency and pulse number of repetitive transcranial magnetic stimulation on the inter-reversal time of perceptual reversal on the right superior parietal lobule

    Science.gov (United States)

    Nojima, Kazuhisa; Ge, Sheng; Katayama, Yoshinori; Ueno, Shoogo; Iramina, Keiji

    2010-05-01

    The aim of this study is to investigate the effect of the stimulus frequency and pulses number of repetitive transcranial magnetic stimulation (rTMS) on the inter-reversal time (IRT) of perceptual reversal on the right superior parietal lobule (SPL). The spinning wheel illusion was used as the ambiguous figures stimulation in this study. To investigate the rTMS effect over the right SPL during perceptual reversal, 0.25 Hz 60 pulse, 1 Hz 60 pulse, 0.5 Hz 120 pulse, 1 Hz 120 pulse, and 1 Hz 240 pulse biphasic rTMS at 90% of resting motor threshold was applied over the right SPL and the right posterior temporal lobe (PTL), respectively. As a control, a no TMS was also conducted. It was found that rTMS on 0.25 Hz 60 pulse and 1 Hz 60 pulse applied over the right SPL caused shorter IRT. In contrast, it was found that rTMS on 1 Hz 240-pulse applied over the right SPL caused longer IRT. On the other hand, there is no significant difference between IRTs when the rTMS on 0.5 Hz 120 pulse and 1 Hz 120 pulse were applied over the right SPL. Therefore, the applying of rTMS over the right SPL suggests that the IRT of perceptual reversal is effected by the rTMS conditions such as the stimulus frequency and the number of pulses.

  13. Damage to the superior gluteal nerve after the Hardinge approach to the hip.

    LENUS (Irish Health Repository)

    Ramesh, M

    2012-02-03

    We studied prospectively 81 consecutive patients undergoing hip surgery using the Hardinge (1982) approach. The abductor muscles of the hip in these patients were assessed electrophysiologically and clinically by the modified Trendelenburg test. Power was measured using a force plate. We performed assessment at two weeks, and at three and nine months after operation. At two weeks we found that 19 patients (23%) showed evidence of damage to the superior gluteal nerve. By three months, five of these had recovered. The nine patients with complete denervation at three months showed no signs of recovery when reassessed at nine months. Persistent damage to the nerve was associated with a positive Trendelenburg test.

  14. Xenomelia: a new right parietal lobe syndrome.

    Science.gov (United States)

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

    2011-12-01

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

  15. Mental space travel: damage to posterior parietal cortex prevents egocentric navigation and reexperiencing of remote spatial memories.

    Science.gov (United States)

    Ciaramelli, Elisa; Rosenbaum, R Shayna; Solcz, Stephanie; Levine, Brian; Moscovitch, Morris

    2010-05-01

    The ability to navigate in a familiar environment depends on both an intact mental representation of allocentric spatial information and the integrity of systems supporting complementary egocentric representations. Although the hippocampus has been implicated in learning new allocentric spatial information, converging evidence suggests that the posterior parietal cortex (PPC) might support egocentric representations. To date, however, few studies have examined long-standing egocentric representations of environments learned long ago. Here we tested 7 patients with focal lesions in PPC and 12 normal controls in remote spatial memory tasks, including 2 tasks reportedly reliant on allocentric representations (distance and proximity judgments) and 2 tasks reportedly reliant on egocentric representations (landmark sequencing and route navigation; see Rosenbaum, Ziegler, Winocur, Grady, & Moscovitch, 2004). Patients were unimpaired in distance and proximity judgments. In contrast, they all failed in route navigation, and left-lesioned patients also showed marginally impaired performance in landmark sequencing. Patients' subjective experience associated with navigation was impoverished and disembodied compared with that of the controls. These results suggest that PPC is crucial for accessing remote spatial memories within an egocentric reference frame that enables both navigation and reexperiencing. Additionally, PPC was found to be necessary to implement specific aspects of allocentric navigation with high demands on spontaneous retrieval.

  16. [Parietal Cortices and Body Information].

    Science.gov (United States)

    Naito, Eiichi; Amemiya, Kaoru; Morita, Tomoyo

    2016-11-01

    Proprioceptive signals originating from skeletal muscles and joints contribute to the formation of both the human body schema and the body image. In this chapter, we introduce various types of bodily illusions that are elicited by proprioceptive inputs, and we discuss distinct functions implemented by different parietal cortices. First, we illustrate the primary importance of the motor network in the processing of proprioceptive (kinesthetic) signals originating from muscle spindles. Next, we argue that the right inferior parietal cortex, in concert with the inferior frontal cortex (both regions connected by the inferior branch of the superior longitudinal fasciculus-SLF III), may be involved in the conscious experience of body image. Further, we hypothesize other functions of distinct parietal regions: the association between internal hand motor representation with external object representation in the left inferior parietal cortex, visuo-kinesthetic processing in the bilateral posterior parietal cortices, and the integration of somatic signals from different body parts in the higher-order somatosensory parietal cortices. Our results indicate that a distinct parietal region, in concert with its anatomically and functionally connected frontal regions, probably plays specialized roles in the processing of body-related information.

  17. Short-Term Internet-Search Training Is Associated with Increased Fractional Anisotropy in the Superior Longitudinal Fasciculus in the Parietal Lobe.

    Science.gov (United States)

    Dong, Guangheng; Li, Hui; Potenza, Marc N

    2017-01-01

    The Internet search engine has become an indispensable tool for many people, yet the ways in which Internet searching may alter brain structure and function is poorly understood. In this study, we investigated the influence of short-term Internet-search "training" on white matter microstructure using diffusion tensor imaging (DTI). Fifty-nine valid subjects (Experimental group, 43; Control group, 16) completed the whole procedure: pre- DTI scan, 6-day's training and post- DTI scan. Using track-based spatial statistics, we found increased fractional anisotropy in the right superior longitudinal fasciculus at post-test as compared to pre-test in experimental group. Within the identified region of the right superior longitudinal fasciculus, decreased radial diffusivity (RD), and unchanged axial diffusivity (AD) were observed. These results suggest that short-term Internet-search training may increase white-matter integrity in the right superior longitudinal fasciculus. A possible mechanism for the observed FA change may involve increased myelination after training, although this possibility warrants additional investigation.

  18. Sensory syndromes in parietal stroke.

    Science.gov (United States)

    Bassetti, C; Bogousslavsky, J; Regli, F

    1993-10-01

    We studied 20 patients with an acute parietal stroke with hemisensory disturbances but no visual field deficit and no or only slight motor weakness, without thalamic involvement on CT or MRI and found three main sensory syndromes. (1) The pseudothalamic sensory syndrome consists of a faciobrachiocrural impairment of elementary sensation (touch, pain, temperature, vibration). All patients have an inferior-anterior parietal stroke involving the parietal operculum, posterior insula, and, in all but one patient, underlying white matter. (2) The cortical sensory syndrome consists of an isolated loss of discriminative sensation (stereognosis, graphesthesia, position sense) involving one or two parts of the body. These patients show a superior-posterior parietal stroke. (3) The atypical sensory syndrome consists of a sensory loss involving all modalities of sensation in a partial distribution. Parietal lesions of different topography are responsible for this clinical picture, which probably represents a minor variant of the two previous sensory syndromes. Neuropsychological dysfunction was present in 17 patients. The only constant association was between conduction aphasia and right-sided pseudothalamic sensory deficit. We conclude that parietal stroke can cause different sensory syndromes depending on the topography of the underlying lesion. Sensory deficits can be monosymptomatic but never present as a "pure sensory stroke" involving face, arm, leg, and trunk together.

  19. Atrophy of the Parietal Lobe in Preclinical Dementia

    Science.gov (United States)

    Jacobs, Heidi I. L.; Van Boxtel, Martin P. J.; Uylings, Harry B. M.; Gronenschild, Ed H. B. M.; Verhey, Frans R.; Jolles, Jelle

    2011-01-01

    Cortical grey matter atrophy patterns have been reported in healthy ageing and Alzheimer disease (AD), but less consistently in the parietal regions of the brain. We investigated cortical grey matter volume patterns in parietal areas. The grey matter of the somatosensory cortex, superior and inferior parietal lobule was measured in 75 older adults…

  20. Atrophy of the Parietal Lobe in Preclinical Dementia

    Science.gov (United States)

    Jacobs, Heidi I. L.; Van Boxtel, Martin P. J.; Uylings, Harry B. M.; Gronenschild, Ed H. B. M.; Verhey, Frans R.; Jolles, Jelle

    2011-01-01

    Cortical grey matter atrophy patterns have been reported in healthy ageing and Alzheimer disease (AD), but less consistently in the parietal regions of the brain. We investigated cortical grey matter volume patterns in parietal areas. The grey matter of the somatosensory cortex, superior and inferior parietal lobule was measured in 75 older adults…

  1. Involuntary hand levitation associated with parietal damage: another alien hand syndrome Movimento involuntário de levitação da mão associado a lesão parietal: uma variante da síndrome da mão alienígena

    Directory of Open Access Journals (Sweden)

    Paulo E.M. Carrilho

    2001-09-01

    Full Text Available The alien hand syndrome (AHS usually consists of an autonomous motor activity perceived as an involuntary and purposeful movement, with a feeling of foreignness of the involved limb, commonly associated with a failure to recognise ownership of the limb in the absence of visual clues. It has been described in association to lesions of the frontal lobes and corpus callosum. However, parietal damage can promote an involuntary, but purposeless, hand levitation, which, sometimes, resembles AHS. In the present study, four patients (cortico-basal ganglionic degeneration -- n=2; Alzheimer's disease -- n=1 and parietal stroke -- n=1 who developed alien hand motor behaviour and whose CT, MRI and/or SPECT have disclosed a major contralateral parietal damage or dysfunction are described. These results reinforce the idea that parietal lobe lesions may also play a role in some patients with purposeless involuntary limb levitation, which is different from the classic forms of AHS.A síndrome da mão alienígena (SMA geralmente consiste de uma atividade motora autônoma involuntária e aparentemente proposital, acompanhada de uma sensação de estranheza em relação ao membro afetado, muitas vezes associada a uma dificuldade em reconhecê-lo na ausência de pistas visuais. Tal síndrome vem sendo descrita em associação a lesões dos lobos frontais e corpo caloso. No entanto, lesões parietais podem promover um quadro de movimento involuntário de levitação da mão, aparentemente desproposital, mas que por vezes lembra uma SMA. No presente estudo, quatro pacientes (degeneração ganglionar córtico-basal -- n=2; doença de Alzheimer -- n=1 e infarto parietal -- n=1 que desenvolveram tal quadro clínico e cujos estudos de TC, RM e SPECT revelaram um maior dano parietal contralateral, são descritos. Os dados encontrados reforçam a teoria que lesões parietais podem representar algum papel na gênese da levitação involuntária e desproposital da mão, a

  2. 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.

    2012-01-01

    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 sti

  3. Parietal versus temporal lobe components in spatial cognition: Setting the mid-point of a horizontal line.

    Science.gov (United States)

    Oliveri, Massimiliano; Vallar, Giuseppe

    2009-09-01

    Recent anatomo-clinical correlation studies have extended to the superior temporal gyrus, the right hemisphere lesion sites associated with the left unilateral spatial neglect, in addition to the traditional posterior-inferior-parietal localization of the responsible lesion (supramarginal gyrus, at the temporo-parietal junction). The study aimed at teasing apart, by means of repetitive transcranial magnetic stimulation (rTMS), the contribution of the inferior parietal lobule (angular gyrus versus supramarginal gyrus) and of the superior temporal gyrus of the right hemisphere, in making judgments about the mid-point of a horizontal line, a widely used task for detecting and investigating spatial neglect. rTMS trains at 25 Hz frequency were delivered over the inferior parietal lobule (angular gyrus and supramarginal gyrus), the superior temporal gyrus and the anterior parietal lobe of the right hemisphere, in 10 neurologically unimpaired participants, performing a line bisection judgment task. rTMS of the inferior parietal lobule at the level of the supramarginal gyrus brought about a rightward error in the bisection judgment, ipsilateral to the side of the rTMS, with stimulation over the other sites being ineffective. The neural correlates of computing the mid-point of a horizontal segment include the right supramarginal gyrus in the inferior parietal lobule and do not extend to the angular gyrus and the superior temporal gyrus. These rTMS data in unimpaired subjects constrain the evidence from lesion studies in brain-damaged patients, emphasizing the major role of a subset of relevant regions.

  4. Holmes and Horrax (1919) revisited: impaired binocular fusion as a cause of "flat vision" after right parietal brain damage - a case study.

    Science.gov (United States)

    Schaadt, Anna-Katharina; Brandt, Stephan A; Kraft, Antje; Kerkhoff, Georg

    2015-03-01

    The complete loss of binocular depth perception ("flat vision") was first thoroughly described by Holmes and Horrax (1919), and has been occasionally reported thereafter in patients with bilateral posterior-parietal lesions. Though partial spontaneous recovery occurred in some cases, the precise cause(s) of this condition remained obscure for almost a century. Here, we describe a unique patient (EH) with a large right-sided occipito-parietal hemorrhage showing a complete loss of visual depth perception for several months post-stroke. EH could well simultaneously describe multiple visual objects - hence did not show simultanagnosia - but at the same time was completely unable to estimate their distance from him. In every 3-D visual scene objects appeared equidistant to him, thus experiencing a total loss of depth perception ("flat vision"). Neurovisual assessments revealed normal functions of the eyes. EH showed bilateral lower field loss and a severely impaired binocular convergent fusion, but preserved stereopsis. Perceptual re-training of binocular fusion resulted in a progressive and finally complete recovery of objective binocular fusion values and subjective binocular depth perception in a far-to-near-space, gradient-like manner. In parallel, visual depth estimation of relative distances improved, whereas stereopsis remained unchanged. Our results show that a complete loss of 3-D depth perception can result from an isolated impairment in binocular fusion. On a neuroanatomical level, this connection could be explained by a selective lesion of area V6/V6A in the medial occipito-parietal cortex that has been associated with the integration of visual space coordinates and sustained eye-positions into a cyclopean visual 3-D percept.

  5. Effect of Meconium on the Contractility of the Superior Mesenteric Artery: A Clue to Intestinal Damage in Gastroschisis.

    Science.gov (United States)

    Karakuş, Osman Z; Solmaz, Bora; Ateş, Oğuz; Ateş, Mehmet; Hakgüder, Gülce; Olguner, Mustafa; Akgür, Feza M

    2015-08-01

    Intestinal damage has been shown to occur when intra-amniotic meconium concentration exceeds threshold level. However, the mechanism of the meconium-induced intestinal damage is still unclear. Intestinal ischemia can cause intestinal damage in gastroschisis. This study was aimed to determine the effects of intra-amniotic meconium on the contractility of superior mesenteric artery (SMA). Eighteen-day-old fertilized chick embryos (Gallus Domesticus) were extirpated and intestines were harvested. The SMA specimens were prepared as 4 mm segments in the organ bath with Krebs-Henseleit buffer. The isometric contraction responses of the SMA specimens were evaluated with norepinephrine, different meconium concentrations, and clear amniotic fluid. Maximum isometric contractions responses (MICR) of the SMA specimens were recorded with an amplifier system on a computer. In the norepinephrine group, MICR was found as 2.92 ± 0.57 mN. While MICR of the 1/100 meconium group (highest meconium concentration) was found as 1.56 ± 0.40 mN, MICR of the clear amniotic fluid group was 0.41 ± 0.07 mN. The MICR of the norepinephrine group was significantly increased compared with the 1/100 meconium and clear amniotic fluid groups. MICR of the 1/100 meconium group was also found to be significantly increased compared with clear amniotic fluid group. No statistically significant difference was found among the meconium subgroups. Intra-amniotic meconium in fetuses with gastroschisis might cause ischemic intestinal damage by reducing the intestinal blood flow. Further studies are needed to show the outcomes of the vasoactive effect of meconium on the SMA blood flow. Georg Thieme Verlag KG Stuttgart · New York.

  6. The right parietal lobe is critical for visual working memory.

    Science.gov (United States)

    Berryhill, Marian E; Olson, Ingrid R

    2008-01-01

    Visual working memory (VWM) permits the maintenance of object identities and their locations across brief delays such as those accompanying eye movements. Recent neuroimaging studies have emphasized the role of the posterior parietal lobe in this process although the specific nature of this involvement in VWM remains controversial. Neuroimaging findings suggest that the parietal lobe may have a general role in remembering various types of visual information whereas neuropsychological findings suggest that parietal involvement is primarily related to motor spatial attention and spatial memory. In the present study, patients with unilateral right parietal lobe damage, lacking symptoms of neglect, were tested in several VWM old/new recognition tasks. Parietal damage lead to impaired performance on all VWM tasks, including spatial, object, and object/spatial conjunction tasks. Deficits were found across several stimulus categories. These results provide neuropsychological support for neuroimaging results, and more generally indicate that the parietal lobe serves a general role in diverse forms of VWM.

  7. Parietal cell vagotomy.

    Science.gov (United States)

    Cumberland, V H; Coupland, G A

    1975-07-12

    In a series of 100 consecutive patients who had parietal cell vagotomy performed, no drainage procedure was performed in 56 while 44 were drained. Dumping was significantly less in those who were not drained. All patients were tested for adequacy of vagotomy and for function of the nerve of Latarget at operation. Four patients have had further operations, two for proven recurrent ulcers. Parietal cell vagotomy has given excellent clinical results in this group of patients.

  8. Right parietal dominance in spatial egocentric discrimination.

    Science.gov (United States)

    Loayza, F R; Fernández-Seara, M A; Aznárez-Sanado, M; Pastor, M A

    2011-03-15

    Egocentric tactile perception is crucial for skilled hand motor control. In order to better understand the brain functional underpinnings related to this basic sensorial perception, we performed a tactile perception functional magnetic resonance imaging (fMRI) experiment with two aims. The first aim consisted of characterizing the neural substrate of two types of egocentric tactile discrimination: the spatial localization (SLD) and simultaneity succession discrimination (SSD) in both hands to define hemispheric dominance for these tasks. The second goal consisted of characterizing the brain activation related to the spatial attentional load, the functional changes and their connectivity patterns induced by the psychometric performance (PP) during SLD. We used fMRI in 25 right-handed volunteers, applying pairs of sinusoidal vibratory stimuli on eight different positions in the palmar surface of both hands. Subjects were required either to identify the stimulus location with respect to an imaginary midline (SLD), to discriminate the simultaneity or succession of a stimuli pair (SSD) or to simply respond to stimulus detection. We found a fronto-parietal network for SLD and frontal network for SSD. During SLD we identified right hemispheric dominance with increased BOLD activation and functional interaction of the right supramarginal gyrus with contralateral intra-parietal sulcus for right and left hand independently. Brain activity correlated to spatial attentional load was found in bilateral structures of intra-parietal sulcus, precuneus extended to superior parietal lobule, pre-supplementary motor area, frontal eye fields and anterior insulae for both hands. We suggest that the right supramarginal gyrus and its interaction with intra-parietal lobule may play a pivotal role in the phenomenon of tactile neglect in right fronto-parietal lesions. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. Parcellation of left parietal tool representations by functional connectivity

    Science.gov (United States)

    Garcea, Frank E.; Z. Mahon, Bradford

    2014-01-01

    Manipulating a tool according to its function requires the integration of visual, conceptual, and motor information, a process subserved in part by left parietal cortex. How these different types of information are integrated and how their integration is reflected in neural responses in the parietal lobule remains an open question. Here, participants viewed images of tools and animals during functional magnetic resonance imaging (fMRI). K-means clustering over time series data was used to parcellate left parietal cortex into subregions based on functional connectivity to a whole brain network of regions involved in tool processing. One cluster, in the inferior parietal cortex, expressed privileged functional connectivity to the left ventral premotor cortex. A second cluster, in the vicinity of the anterior intraparietal sulcus, expressed privileged functional connectivity with the left medial fusiform gyrus. A third cluster in the superior parietal lobe expressed privileged functional connectivity with dorsal occipital cortex. Control analyses using Monte Carlo style permutation tests demonstrated that the clustering solutions were outside the range of what would be observed based on chance ‘lumpiness’ in random data, or mere anatomical proximity. Finally, hierarchical clustering analyses were used to formally relate the resulting parcellation scheme of left parietal tool representations to previous work that has parcellated the left parietal lobule on purely anatomical grounds. These findings demonstrate significant heterogeneity in the functional organization of manipulable object representations in left parietal cortex, and outline a framework that generates novel predictions about the causes of some forms of upper limb apraxia. PMID:24892224

  10. The role of the right parietal lobe in anorexia nervosa.

    Science.gov (United States)

    Nico, D; Daprati, E; Nighoghossian, N; Carrier, E; Duhamel, J-R; Sirigu, A

    2010-09-01

    Patients with anorexia nervosa (AN) overestimate their size despite being severely underweight. Whether this misperception echoes an underlying emotional disturbance or also reflects a genuine body-representation deficit is debatable. Current measures inquire directly about subjective perception of body image, thus distinguishing poorly between top-down effects of emotions/attitudes towards the body and disturbances due to proprioceptive disorders/distorted body schema. Disorders of body representation also emerge following damage to the right parietal lobe. The possibility that parietal dysfunction might contribute to AN is suspected, based on the demonstrated association of spatial impairments, comparable to those found after parietal lesion, with this syndrome. We used a behavioral task to compare body knowledge in severe anorexics (n=8), healthy volunteers (n=11) and stroke patients with focal damage to the left/right parietal lobe (n=4). We applied a psychophysical procedure based on the perception, in the dark, of an approaching visual stimulus that was turned off before reaching the observer. Participants had to predict whether the stimulus would have hit/missed their body, had it continued its linear motion. Healthy volunteers and left parietal patients estimated body boundaries very close to the real ones. Conversely, anorexics and right parietal patients underestimated eccentricity of their left body boundary. These findings are in line with the role the parietal cortex plays in developing and maintaining body representation, and support the possibility for a neuropsychological component in the pathogenesis of anorexia, offering alternative approaches to treatment of the disorder.

  11. Parietal lobe epilepsy.

    Science.gov (United States)

    Salanova, Vicenta

    2012-10-01

    Patients with parietal lobe epilepsy (PLE) exhibit an electroclinical epilepsy syndrome that is rarely seen even at large epilepsy centers. Clinically, most patients with PLE exhibit a somatosensory aura that may include painful dysesthesias, though vertigo, aphasia, disturbances of one's body image also occur, when ictal propagation occurs from the parietal lobe to the supplementary motor area, hypermotor manifestations are noted. When temporolimbic propagation occurs, complex visual or auditory hallucinations and automatisms may appear. Scalp electroencephalogram (EEG) is often nonlocalizing. Ictal EEG is rarely localizing in PLE, and invasive EEG is often required for definitive localization and functional mapping. Recent advances in clinical neurophysiology during the evaluation of patients with refractory partial epilepsy include Ictal magnetic source imaging (MSI). Combined EEG and functional magnetic resonance imaging (EEG-fMRI) may be useful for patients with PLE to refine the localization in patients undergoing a presurgical evaluation. High-frequency oscillations (HFOs) are more concentrated inside the seizure onset zone (SOZ), indicating that they may be used as interictal scalp EEG biomarker for the SOZ. When medical therapy fails, resective epilepsy surgery can result in seizure freedom or significant reduction especially when a lesion is present.

  12. Parietal cheiro-oral syndrome.

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    Yasuda, Y; Watanabe, T; Ogura, A

    2000-12-01

    Cheiro-oral syndrome due to a parietal lesion has been reported in conjuction with a brain tumor, infarction and migraine. Only six reports of cheiro-oral syndrome due to a parietal infarction have been reported to date. We treated a 45-year-old woman with cheiro-oral syndrome due to a parietal infarction. Her sensory disturbance was characterized by paresthesia in the lower face and hand on the left side, and severe involvement of stereognosis and graphesthesia in the left hand. The pathogenesis of parietal cheiro-oral syndrome is discussed.

  13. Apraxia and the Parietal Lobes

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    Goldenberg, Georg

    2009-01-01

    The widely held belief in a central role of left parietal lesions for apraxia can be traced back to Liepmann's model of a posterior to anterior stream converting mental images of intended action into motor execution. Although this model has undergone significant changes, its modern descendants still attribute the parietal contribution to the…

  14. Parietal intraparenchymal Schwannoma: case report

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    Kim, Seong Hwan; Chung, Tae Woong; Yoon, Woong; Jeong, Gwang Woo; Kang, Heoung Keun [Chonnam National University Hospital, Kwangju (Korea, Republic of)

    2008-10-15

    We report a case of an intraparenchymal schwannoma of the left parietal lobe. A 51-year-old woman was admitted to our hospital with complaints of intermittent headaches. Computed tomography and magnetic resonance images revealed a 1.3 cm sized intra-axial homogeneous enhancing mass in the left parietal lobe. The lesion was pathologically confirmed to be a schwannoma.

  15. Antisaccade generation is impaired after parietal lobe lesions.

    Science.gov (United States)

    Sharpe, James A; Cheng, Ping; Eizenman, Moshe

    2011-09-01

    Antisaccades are directed away from visual targets. Impaired antisaccade generation has been attributed to frontal lobe damage. We studied antisaccades in patients with unilateral focal parietal lobe lesions. Normal subjects (N = 10) instructed to make 10° antisaccades opposite to a 100-ms target flash 10° to the right or left of center made antisaccades in 86.1% of trials. Patients (N = 13) made antisaccades contraversive to their lesions in 55.4% of trials and 50.5% of ipsiversive trials. In other trials, reflexive saccades occurred toward the target flash. Nine patients with imaged lesions overlapping in parietal lobe white matter showed subnormal antisaccade generation. Antisaccades provide a means of measuring voluntary saccade function of the parietal lobes independent of visual guidance. Impaired suppression of reflexive saccades and generation of antisaccades is attributed to disconnection of parietal lobe from frontal lobe ocular motor areas. © 2011 New York Academy of Sciences.

  16. Cerebello-thalamo-cortical projections to the posterior parietal cortex in the macaque monkey.

    Science.gov (United States)

    Amino, Y; Kyuhou, S; Matsuzaki, R; Gemba, H

    2001-08-17

    The cerebello-thalamo-posterior parietal cortical projections were investigated electrophysiologically and morphologically in macaque monkeys. In anesthetized monkeys, electrical stimulation of every cerebellar nucleus evoked marked surface-positive, depth-negative (s-P, d-N) cortical field potentials in the superior parietal lobule and the cortical bank of the intraparietal sulcus, but no responses in the inferior parietal lobule. Tract-tracing experiments combining the anterograde method with the retrograde one indicated that the interposed and lateral cerebellar nuclei projected to the posterior parietal cortex mainly through the nucleus ventral lateralis caudalis of the thalamus. The significance of the projections is discussed in connection with cognitive functions.

  17. Role of parietal regions in episodic memory retrieval: The dual attentional processes hypothesis

    OpenAIRE

    Cabeza, Roberto

    2008-01-01

    Although parietal cortex is frequently activated during episodic memory retrieval, damage to this region does not markedly impair episodic memory. To account for these and other findings, a new dual attentional processes (DAP) hypothesis is proposed. According to this hypothesis, dorsal parietal cortex (DPC) contributes top-down attentional processes guided by retrieval goals, whereas ventral parietal cortex (VPC) contributes bottom-up attentional processes captured by the retrieval output. C...

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

    Science.gov (United States)

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

    2015-07-01

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

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

    Science.gov (United States)

    Sakurai, Yasuhisa

    2017-04-01

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

  20. rTMS over bilateral inferior parietal cortex induces decrement of spatial sustained attention

    Science.gov (United States)

    Lee, Jeyeon; Ku, Jeonghun; Han, Kiwan; Park, Jinsick; Lee, Hyeongrae; Kim, Kyung Ran; Lee, Eun; Husain, Masud; Yoon, Kang Jun; Kim, In Young; Jang, Dong Pyo; Kim, Sun I.

    2013-01-01

    Sustained attention is an essential brain function that enables a subject to maintain attention level over the time of a task. In previous work, the right inferior parietal lobe (IPL) has been reported as one of the main brain regions related to sustained attention, however, the right lateralization of vigilance/sustained attention is unclear because information about the network for sustained attention is traditionally provided by neglect patients who typically have right brain damage. Here, we investigated sustained attention by applying a virtual lesion technique, transcranial magnetic stimulation (TMS), over the left and right superior parietal lobe (SPL) and IPL. We used two different types of visual sustained attention tasks: spatial (location based) and non-spatial (feature based). When the participants performed the spatial task, repetitive TMS (rTMS) over either the right or left IPL induced a significant decrement of sustained attention causing a progressive increment of errors and response time. In contrast, participants' performance was not changed by rTMS on the non-spatial task. Also, omission errors (true negative) gradually increased with time on right and left IPL rTMS conditions, while commission errors (false positive) were relatively stable. These findings suggest that the maintenance of attention, especially in tasks regarding spatial location, is not uniquely lateralized to the right IPL, but may also involve participation of the left IPL. PMID:23403477

  1. rTMS over bilateral inferior parietal cortex induces decrement of spatial sustained attention

    Directory of Open Access Journals (Sweden)

    Jeyeon eLee

    2013-02-01

    Full Text Available Sustained attention is an essential brain function that enables a subject to maintain attention level over the time of a task. In previous work, the right inferior parietal lobe (IPL has been reported as one of the main brain regions related to sustained attention, however, the right lateralization of vigilance/sustained attention is unclear because information about the network for sustained attention is traditionally provided by neglect patients who typically have right brain damage. Here, we investigated sustained attention by applying a virtual lesion technique, transcranial magnetic stimulation (TMS, over the left and right superior parietal lobe (SPL and IPL. We used two different types of visual sustained attention tasks: spatial (location based and non-spatial (feature based. When the participants performed the spatial task, repetitive TMS (rTMS over either the right or left IPL induced a significant decrement of sustained attention causing a progressive increment of errors and response time. In contrast, participants’ performance was not changed by rTMS on the non-spatial task. Also, omission errors (true negative gradually increased with time on right and left IPL rTMS conditions, while commission errors (false positive were relatively stable. These findings suggest that the maintenance of attention, especially in tasks regarding spatial location, is not uniquely lateralized to the right IPL, but may also involve participation of the left IPL as well.

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

    Science.gov (United States)

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

    2009-10-07

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

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

    Science.gov (United States)

    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.

  4. Global increase in task-related fronto-parietal activity after focal frontal lobe lesion.

    Science.gov (United States)

    Woolgar, Alexandra; Bor, Daniel; Duncan, John

    2013-09-01

    A critical question for neuropsychology is how complex brain networks react to damage. Here, we address this question for the well-known executive control or multiple-demand (MD) system, a fronto-parietal network showing increased activity with many different kinds of cognitive demand, including standard tests of fluid intelligence. Using fMRI, we ask how focal frontal lobe damage affects MD activity during a standard fluid intelligence task. Despite poor behavioral performance, frontal patients showed increased fronto-parietal activity relative to controls. The activation difference was not accounted for by difference in IQ. Moreover, rather than specific focus on perilesional or contralesional cortex, additional recruitment was distributed throughout the MD regions and surrounding cortex and included parietal MD regions distant from the injury. The data suggest that, following local frontal lobe damage, there is a global compensatory recruitment of an adaptive and integrated fronto-parietal network.

  5. Neural networks underlying parietal lobe seizures: a quantified study from intracerebral recordings.

    Science.gov (United States)

    Bartolomei, Fabrice; Gavaret, Martine; Hewett, Russell; Valton, Luc; Aubert, Sandrine; Régis, Jean; Wendling, Fabrice; Chauvel, Patrick

    2011-02-01

    In this study we have quantified the "epileptogenicity" of several brain regions in seizures originating in the posterior parietal cortex in 17 patients investigated by intracerebral recordings using stereotactic EEG (SEEG). Epileptogenicity of brain structures was quantified according to the "epileptogenicity index" (EI), a way to quantify rapid discharges at seizure onset. Seven patients had maximal epileptogenicity in the superior parietal lobule-BA area 7 (Gr1), 2 patients in the superior parietal lobule-area 5 (Gr2), 4 patients in inferior parietal lobule (Gr3) and 4 in the opercular region (Gr4). A large majority of patients (15/17 (88%)) reported to have at least one aura during the course of their disease. Somato-sensory manifestations were reported in the four groups. Vestibular disturbance was observed mainly in seizures from the superior parietal lobule (Gr1 and 2). Ipsilateral version was the most frequent objective manifestation (64%). Hyperkinetic behaviour (motor agitation) was found to be frequent, observed in 4/17 cases (23%) and observed in seizures from inferior parietal regions. In conclusion, the electrophysiological organization and the clinical manifestations of PLS are various and complex. The subjective manifestations are frequent and often suggestive, therefore must be actively sought. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Role of parietal regions in episodic memory retrieval: the dual attentional processes hypothesis.

    Science.gov (United States)

    Cabeza, Roberto

    2008-01-01

    Although parietal cortex is frequently activated during episodic memory retrieval, damage to this region does not markedly impair episodic memory. To account for these and other findings, a new dual attentional processes (DAP) hypothesis is proposed. According to this hypothesis, dorsal parietal cortex (DPC) contributes top-down attentional processes guided by retrieval goals, whereas ventral parietal cortex (VPC) contributes bottom-up attentional processes captured by the retrieval output. Consistent with this hypothesis, DPC activity increases with retrieval effort whereas VPC activity increases with confidence in old and new responses. The DAP hypothesis can also account for the overlap of parietal activations across different cognitive domains and for opposing effects of parietal activity on encoding vs. retrieval. Finally, the DAP hypothesis explains why VPC lesions yield a memory neglect syndrome: a deficit in spontaneously reporting relevant memory details but not in accessing the same details when guided by specific questions.

  7. Body and movement: consciousness in the parietal lobes.

    Science.gov (United States)

    Daprati, Elena; Sirigu, Angela; Nico, Daniele

    2010-02-01

    A critical issue related to the notion of identity concerns our ability to discriminate between internally and externally generated stimuli. This basic mechanism likely relies on perceptual and motor information, and requires that both motor plans and the resulting activity be continuously mapped on a reliable body representation. It has been widely demonstrated that the parietal cortices of the two hemispheres play a crucial role, albeit differently specialized, in both monitoring internal representation of our own actions and sustaining body representation. Ample neuropsychological evidence indicates that while damage to the left parietal cortex affects the ability to generate and/or monitor an internal model of one's own movement, lesions of the right parietal lobe are largely responsible for severe perturbations of the internal representation of one's own body. In the present paper, we discuss the processes involved in body perception and self-recognition and propose a tentative model describing how the right and left parietal cortices contribute in integrating various sources of information to produce the unique, elementary experience of one's own body in motion. The ecological value of this process in constructing identity and autobiographical experience will be discussed.

  8. Uncertain relational reasoning in the parietal cortex.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Megumi, Fukuda; Bahrami, Bahador; Kanai, Ryota; Rees, Geraint

    2015-02-15

    The neural mechanisms underlying conscious visual perception have been extensively investigated using bistable perception paradigms. Previous functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) studies suggest that the right anterior superior parietal (r-aSPL) and the right posterior superior parietal lobule (r-pSPL) have opposite roles in triggering perceptual reversals. It has been proposed that these two areas are part of a hierarchical network whose dynamics determine perceptual switches. However, how these two parietal regions interact with each other and with the rest of the brain during bistable perception is not known. Here, we investigated such a model by recording brain activity using fMRI while participants viewed a bistable structure-from-motion stimulus. Using dynamic causal modeling (DCM), we found that resolving such perceptual ambiguity was specifically associated with reciprocal interactions between these parietal regions and V5/MT. Strikingly, the strength of bottom-up coupling between V5/MT to r-pSPL and from r-pSPL to r-aSPL predicted individual mean dominance duration. Our findings are consistent with a hierarchical predictive coding model of parietal involvement in bistable perception and suggest that visual information processing underlying spontaneous perceptual switches can be described as changes in connectivity strength between parietal and visual cortical regions.

  10. The Superior Transvelar Approach to the Fourth Ventricle and Brainstem

    OpenAIRE

    Ezer, Haim; Banerjee, Anirban Deep; Bollam, Papireddy; Guthikonda, Bharat; Nanda, Anil

    2012-01-01

    Objective The superior transvelar approach is used to access pathologies located in the fourth ventricle and brainstem. The surgical path is below the venous structures, through the superior medullary velum. Following splitting the tentorial edge, near the tentorial apex, the superior medullary velum is split in the cerebello-mesencephalic fissure. Using the supracerebellar infratentorial, transtentorial or parietal interhemispheric routes, the superior medullary velum is approached. Splittin...

  11. Cortical networks for visual reaching: physiological and anatomical organization of frontal and parietal lobe arm regions.

    Science.gov (United States)

    Johnson, P B; Ferraina, S; Bianchi, L; Caminiti, R

    1996-01-01

    The functional and structural properties of the dorsolateral frontal lobe and posterior parietal proximal arm representations were studied in macaque monkeys. Physiological mapping of primary motor (MI), dorsal premotor (PMd), and posterior parietal (area 5) cortices was performed in behaving monkeys trained in an instructed-delay reaching task. The parietofrontal corticocortical connectivities of these same areas were subsequently examined anatomically by means of retrograde tracing techniques. Signal-, set-, movement-, and position-related directional neuronal activities were distributed nonuniformly within the task-related areas in both frontal and parietal cortices. Within the frontal lobe, moving caudally from PMd to the MI, the activity that signals for the visuo-spatial events leading to target localization decreased, while the activity more directly linked to movement generation increased. Physiological recordings in the superior parietal lobule revealed a gradient-like distribution of functional properties similar to that observed in the frontal lobe. Signal- and set-related activities were encountered more frequently in the intermediate and ventral part of the medial bank of the intraparietal sulcus (IPS), in area MIP. Movement-and position-related activities were distributed more uniformly within the superior parietal lobule (SPL), in both dorsal area 5 and in MIP. Frontal and parietal regions sharing similar functional properties were preferentially connected through their association pathways. As a result of this study, area MIP, and possibly areas MDP and 7m as well, emerge as the parietal nodes by which visual information may be relayed to the frontal lobe arm region. These parietal and frontal areas, along with their association connections, represent a potential cortical network for visual reaching. The architecture of this network is ideal for coding reaching as the result of a combination between visual and somatic information.

  12. High Frequency rTMS over the Left Parietal Lobule Increases Non-Word Reading Accuracy

    Science.gov (United States)

    Costanzo, Floriana; Menghini, Deny; Caltagirone, Carlo; Oliveri, Massimiliano; Vicari, Stefano

    2012-01-01

    Increasing evidence in the literature supports the usefulness of Transcranial Magnetic Stimulation (TMS) in studying reading processes. Two brain regions are primarily involved in phonological decoding: the left superior temporal gyrus (STG), which is associated with the auditory representation of spoken words, and the left inferior parietal lobe…

  13. Bottom-up Visual Integration in the Medial Parietal Lobe.

    Science.gov (United States)

    Pflugshaupt, Tobias; Nösberger, Myriam; Gutbrod, Klemens; Weber, Konrad P; Linnebank, Michael; Brugger, Peter

    2016-03-01

    Largely based on findings from functional neuroimaging studies, the medial parietal lobe is known to contribute to internally directed cognitive processes such as visual imagery or episodic memory. Here, we present 2 patients with behavioral impairments that extend this view. Both had chronic unilateral lesions of nearly the entire medial parietal lobe, but in opposite hemispheres. Routine neuropsychological examination conducted >4 years after the onset of brain damage showed little deficits of minor severity. In contrast, both patients reported persistent unusual visual impairment. A comprehensive series of tachistoscopic experiments with lateralized stimulus presentation and comparison with healthy participants revealed partial visual hemiagnosia for stimuli presented to their contralesional hemifield, applying inferential single-case statistics to evaluate deficits and dissociations. Double dissociations were found in 4 experiments during which participants had to integrate more than one visual element, either through comparison or formation of a global gestalt. Against the background of recent neuroimaging findings, we conclude that of all medial parietal structures, the precuneus is the most likely candidate for a crucial involvement in such bottom-up visual integration. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Theta and Alpha Oscillations during the Retention Period of Working Memory by rTMS Stimulating the Parietal Lobe.

    Science.gov (United States)

    Li, Song; Jin, Jing-Na; Wang, Xin; Qi, Hong-Zhi; Liu, Zhi-Peng; Yin, Tao

    2017-01-01

    Studies on repetitive transcranial magnetic stimulation (rTMS) have shown that stimulating the parietal lobe, which plays a role in memory storage, can enhance performance during the "retention" process of working memory (WM). However, the mechanism of rTMS effect during this phase is still unclear. In this study, we stimulated the superior parietal lobe (SPL) using 5-Hz rTMS in 26 participants and recorded electroencephalography (EEG) while they performed a delayed-recognition WM task. The analyses included the comparisons of event-related spectral perturbation (ERSP) value variations in theta (4-7 Hz) and alpha (8-14 Hz) band frequencies between conditions (rTMS vs. sham), as well as the correlations between different brain areas. Following rTMS, the ERSP values of theta-band oscillations were significantly increased in the parietal and occipital-parietal brain areas (P parietal area (P parietal and left prefrontal areas were positively correlated with the response time (RT) variations (by using rTMS, the more subject RT decreased, the more ERSP value of theta oscillation increased). The ERSP value variations of alpha-band oscillations in the left parietal and bilateral prefrontal areas were negatively correlated with RT variations (by using rTMS, the more RT of the subject decreased, the more ERSP value of alpha oscillation decreased). Inter-sites phase synchronization of theta-band EEG between the left parietal and left prefrontal areas, as well as alpha-band EEG between the left parietal and bilateral prefrontal areas were enhanced by rTMS. These results indicated that activities of both parietal and prefrontal areas were required for information storage, and these activities were related to the behavioral responses. Moreover, the connectivity between these two regions was intensified following rTMS. Thus, rTMS may affect the frontal area indirectly via the frontal parietal pathway.

  15. Abnormal Parietal Brain Function in ADHD: Replication and Extension of Previous EEG Beta Asymmetry Findings

    Directory of Open Access Journals (Sweden)

    T. Sigi eHale

    2014-07-01

    Full Text Available Background: Abundant work indicates ADHD abnormal posterior brain structure and function, including abnormal structural and functional asymmetries and reduced corpus callosum size. However, this literature has attracted considerably less research interest than fronto-striatal findings. Objective: To help address this imbalance, the current study replicates and extends our previous work showing abnormal parietal brain function in ADHD adults during the Conner’s continuous performance test (CPT. Method: Our previous study found that ADHD adults had increased rightward EEG beta (16-21 Hz asymmetry in inferior parietal brain regions during the CPT (p=.00001, and that this metric exhibited a lack of normal correlation (i.e., observed in controls with beta asymmetry at temporal-parietal regions. We re-tested these effects in a new ADHD sample, and with both new and old samples combined. We additionally examined: a EEG asymmetry in multiple frequency bands, b unilateral effects for all asymmetry findings, and c the association between EEG asymmetry and a battery of cognitive tests. Results: We replicated our original findings, again demonstrating abnormal rightward inferior parietal beta asymmetry in adults with ADHD during the CPT, and again this metric exhibited abnormal reduced correlation to temporal-parietal beta asymmetry. Novel analyses also demonstrated a broader pattern of rightward beta and theta asymmetry across inferior, superior, and temporal-parietal brain regions, and showed that rightward parietal asymmetry in ADHD was atypically associated with multiple cognitive tests. Conclusion: Abnormal increased rightward parietal EEG beta asymmetry is an important feature of ADHD. We speculate that this phenotype may occur with any form of impaired capacity for top-down task-directed control over sensory encoding functions, and that it may reflect associated increases of attentional shifting and compensatory sustained/selective attention.

  16. Prostate Cancer Presenting with Parietal Bone Metastasis

    Science.gov (United States)

    Pare, Abdoul Karim; Abubakar, Babagana Mustapha; Kabore, Moussa

    2017-01-01

    Bone metastases from prostate cancer are very common. They are usually located on the axial skeleton. However, cranial bone metastases especially to the parietal bone are rare. We report a case of metastatic prostate cancer presenting with left parietal bone metastasis in a patient with no urological symptoms or signs. We should consider prostate cancer in any man above 60 years presenting unusual bone lesions.

  17. Thalamo-cortical projections to the posterior parietal cortex in the monkey.

    Science.gov (United States)

    Matsuzaki, Ryuichi; Kyuhou, Shin-ichi; Matsuura-Nakao, Kazuko; Gemba, Hisae

    2004-01-23

    Thalamo-cortical projections to the posterior parietal cortex (PPC) were investigated electrophysiologically in the monkey. Cortical field potentials evoked by the thalamic stimulation were recorded with electrodes chronically implanted on the cortical surface and at a 2.0-3.0 mm cortical depth in the PPC. The stimulation of the nucleus lateralis posterior (LP), nucleus ventralis posterior lateralis pars caudalis (VPLc), and nucleus pulvinaris lateralis (Pul.l) and medialis (Pul.m) induced surface-negative, depth-positive potentials in the PPC. The LP and VPLc projected mainly to the superior parietal lobule (SPL) and the anterior bank of the intraparietal sulcus (IPS), and the Pul.m mainly to the inferior parietal lobule (IPL) and the posterior bank of the IPS. The Pul.l had projections to all of the SPL, the IPL and both the banks. The significance of the projections is discussed in connection with motor functions.

  18. Abnormal parietal encephalomalacia associated with schizophrenia

    Science.gov (United States)

    Pan, Fen; Wang, Jun-Yuan; Xu, Yi; Huang, Man-Li

    2017-01-01

    Abstract Rationale: It is widely believed that structural abnormalities of the brain contribute to the pathophysiology of schizophrenia. The parietal lobe is a central hub of multisensory integration, and abnormities in this region might account for the clinical features of schizophrenia. However, few cases of parietal encephalomalacia associated with schizophrenia have been described. Patient concerns and Diagnoses: In this paper, we present a case of a 25-year-old schizophrenia patient with abnormal parietal encephalomalacia. The patient had poor nutrition and frequently had upper respiratory infections during childhood and adolescence. She showed severe schizophrenic symptoms such as visual hallucinations for 2 years. After examining all her possible medical conditions, we found that the patient had a lesion consistent with the diagnosis of encephalomalacia in her right parietal lobe and slight brain atrophy. Interventions: The patient was prescribed olanzapine (10 mg per day). Outcomes: Her symptoms significantly improved after antipsychotic treatment and were still well controlled 1 year later. Lessons: This case suggested that parietal encephalomalacia, which might be caused by inflammatory and infectious conditions in early life and be aggravated by undernutrition, might be implicated in the etiology of schizophrenia. PMID:28272261

  19. Parietal cortex mediates conscious perception of illusory gestalt.

    Science.gov (United States)

    Zaretskaya, Natalia; Anstis, Stuart; Bartels, Andreas

    2013-01-09

    Grouping local elements into a holistic percept, also known as spatial binding, is crucial for meaningful perception. Previous studies have shown that neurons in early visual areas V1 and V2 can signal complex grouping-related information, such as illusory contours or object-border ownerships. However, relatively little is known about higher-level processes contributing to these signals and mediating global Gestalt perception. We used a novel bistable motion illusion that induced alternating and mutually exclusive vivid conscious experiences of either dynamic illusory contours forming a global Gestalt or moving ungrouped local elements while the visual stimulation remained the same. fMRI in healthy human volunteers revealed that activity fluctuations in two sites of the parietal cortex, the superior parietal lobe and the anterior intraparietal sulcus (aIPS), correlated specifically with the perception of the grouped illusory Gestalt as opposed to perception of ungrouped local elements. We then disturbed activity at these two sites in the same participants using transcranial magnetic stimulation (TMS). TMS over aIPS led to a selective shortening of the duration of the global Gestalt percept, with no effect on that of local elements. The results suggest that aIPS activity is directly involved in the process of spatial binding during effortless viewing in the healthy brain. Conscious perception of global Gestalt is therefore associated with aIPS function, similar to attention and perceptual selection.

  20. Understanding the parietal lobe syndrome from a neurophysiological and evolutionary perspective.

    Science.gov (United States)

    Caminiti, Roberto; Chafee, Matthew V; Battaglia-Mayer, Alexandra; Averbeck, Bruno B; Crowe, David A; Georgopoulos, Apostolos P

    2010-06-01

    In human and nonhuman primates parietal cortex is formed by a multiplicity of areas. For those of the superior parietal lobule (SPL) there exists a certain homology between man and macaques. As a consequence, optic ataxia, a disturbed visual control of hand reaching, has similar features in man and monkeys. Establishing such correspondence has proven difficult for the areas of the inferior parietal lobule (IPL). This difficulty depends on many factors. First, no physiological information is available in man on the dynamic properties of cells in the IPL. Second, the number of IPL areas identified in the monkey is paradoxically higher than that so far described in man, although this issue will probably be reconsidered in future years, thanks to comparative imaging studies. Third, the consequences of parietal lesions in monkeys do not always match those observed in humans. This is another paradox if one considers that, in certain cases, the functional properties of neurons in the monkey's IPL would predict the presence of behavioral skills, such as construction capacity, that however do not seem to emerge in the wild. Therefore, constructional apraxia, which is well characterized in man, has never been described in monkeys and apes. Finally, only certain aspects, i.e. hand directional hypokinesia and gaze apraxia (Balint's psychic paralysis of gaze), of the multifaceted syndrome hemispatial neglect have been described in monkeys. These similarities, differences and paradoxes, among many others, make the study of the evolution and function of parietal cortex a challenging case.

  1. Right Fronto-Parietal Dysfunction in Children with ADHD and Developmental Dyslexia as Determined by Line Bisection Judgements

    Science.gov (United States)

    Waldie, Karen E.; Hausmann, Markus

    2010-01-01

    Visual line bisection is a reliable and valid laterality task that is typically used with patients with acquired brain damage to assess right hemisphere functioning. Neurologically normal individuals tend to bisect lines to the left of the objective midline whereas those with right parietal damage bisect lines to the right. In this study children…

  2. Apraxia, pantomime and the parietal cortex

    Directory of Open Access Journals (Sweden)

    E. Niessen

    2014-01-01

    In contrast to previous suggestions, current analyses show that both lesion and functional studies support the notion of a left-hemispheric fronto-(temporal-parietal network underlying pantomiming object use. Furthermore, our review demonstrates that the left parietal cortex plays a key role in pantomime-related processes. More specifically, stringently controlled fMRI-studies suggest that in addition to storing motor schemas, left parietal cortex is also involved in activating these motor schemas in the context of pantomiming object use. In addition to inherent differences between structural and functional imaging studies and consistent with the dedifferentiation hypothesis, the age difference between young healthy subjects (typically included in functional imaging studies and elderly neurological patients (typically included in structural lesion studies may well contribute to the finding of a more distributed representation of pantomiming within the motor-dominant left hemisphere in the elderly.

  3. Gelastic seizures involving the left parietal lobe.

    Science.gov (United States)

    Machado, René Andrade; Astencio, Adriana Goicoechea

    2012-01-01

    Gelastic seizures have been described in various epilepsies arising from the temporal or frontal lobes, although the most commonly encountered form is related to the presence of a hypothalamic hamartoma. We describe a patient with gelastic seizures involving the left parietal lobe. Our patient, an 8-year-old girl, underwent interictal video/EEG monitoring and MRI. The seizures consisted of brief staring followed by smiling and laughing. Electroencephalography during the gelastic seizures showed rhythmic spikes and waves in the left parietal lobe. MRI revealed the characteristic features of focal cortical dysplasia. Our findings suggest that the left parietal lobe may actively participate in the particular epileptogenic network generating gelastic seizures. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Parietal Lobes in Schizophrenia: Do They Matter?

    Science.gov (United States)

    Yildiz, Murat; Borgwardt, Stefan J.; Berger, Gregor E.

    2011-01-01

    Objective. Despite observations that abnormal parietal lobe (PL) function is associated with psychotic-like experiences, our knowledge about the nature of PL involvement in schizophrenia is modest. The objective of this paper is to investigate the role of the PL in schizophrenia. Method. Medline databases were searched for English language publications using the following key words: parietal lobe, combined with schizophrenia, lesions, epilepsy, cognition, rare genetic disorders, MRI, fMRI, PET, and SPECT, respectively, followed by cross-checking of references. Results. Imaging studies in childhood onset schizophrenia suggest that grey matter abnormalities start in parietal and occipital lobes and proceed to frontal regions. Although, the findings are inconsistent, several studies with patients at risk to develop schizophrenia indicate early changes in the PL. Conclusions. We want to propose that in a proportion of individuals with emerging schizophrenia structural and functional alterations may start in the PL and progress to frontal regions. PMID:22937268

  5. Apraxia, pantomime and the parietal cortex.

    Science.gov (United States)

    Niessen, E; Fink, G R; Weiss, P H

    2014-01-01

    Apraxia, a disorder of higher motor cognition, is a frequent and outcome-relevant sequel of left hemispheric stroke. Deficient pantomiming of object use constitutes a key symptom of apraxia and is assessed when testing for apraxia. To date the neural basis of pantomime remains controversial. We here review the literature and perform a meta-analysis of the relevant structural and functional imaging (fMRI/PET) studies. Based on a systematic literature search, 10 structural and 12 functional imaging studies were selected. Structural lesion studies associated pantomiming deficits with left frontal, parietal and temporal lesions. In contrast, functional imaging studies associate pantomimes with left parietal activations, with or without concurrent frontal or temporal activations. Functional imaging studies that selectively activated parietal cortex adopted the most stringent controls. In contrast to previous suggestions, current analyses show that both lesion and functional studies support the notion of a left-hemispheric fronto-(temporal)-parietal network underlying pantomiming object use. Furthermore, our review demonstrates that the left parietal cortex plays a key role in pantomime-related processes. More specifically, stringently controlled fMRI-studies suggest that in addition to storing motor schemas, left parietal cortex is also involved in activating these motor schemas in the context of pantomiming object use. In addition to inherent differences between structural and functional imaging studies and consistent with the dedifferentiation hypothesis, the age difference between young healthy subjects (typically included in functional imaging studies) and elderly neurological patients (typically included in structural lesion studies) may well contribute to the finding of a more distributed representation of pantomiming within the motor-dominant left hemisphere in the elderly.

  6. The Predictive Nature of Pseudoneglect for Visual Neglect: Evidence from Parietal Theta Burst Stimulation.

    Directory of Open Access Journals (Sweden)

    Alice Varnava

    Full Text Available Following parietal damage most patients with visual neglect bisect horizontal lines significantly away from the true centre. Neurologically intact individuals also misbisect lines; a phenomenon referred to as 'pseudoneglect'. In this study we examined the relationship between neglect and pseudoneglect by testing how patterns of pre-existing visuospatial asymmetry predict asymmetry caused by parietal interference. Twenty-four participants completed line bisection and Landmark tasks before receiving continuous theta burst stimulation to the left or right angular gyrus. Results showed that a pre-existing pattern of left pseudoneglect (i.e. right bias, but not right pseudoneglect, predicts left neglect-like behaviour during line bisection following right parietal cTBS. This correlation is consistent with the view that neglect and pseudoneglect arise via a common or linked neural mechanism.

  7. Parietal rTMS distorts the mental number line: simulating 'spatial' neglect in healthy subjects.

    Science.gov (United States)

    Göbel, Silke M; Calabria, Marco; Farnè, Alessandro; Rossetti, Yves

    2006-01-01

    Patients with left-sided visuospatial neglect, typically after damage to the right parietal lobe, show a systematic bias towards larger numbers when asked to bisect a numerical interval. This has been taken as further evidence for a spatial representation of numbers, perhaps akin to a mental number line with smaller numbers represented to the left and larger numbers to the right. Previously, contralateral neglect-like symptoms in physical line bisection have been induced in healthy subjects with repetitive transcranial magnetic stimulation (rTMS) over right posterior parietal lobe. Here we used rTMS over parietal and occipital sites in healthy subjects to investigate spatial representations in a number bisection task. Subjects were asked to name the midpoint of numerical intervals without calculating. On control trials subjects' behaviour was similar to performance reported in physical line bisection experiments. Subjects underestimated the midpoint of the numerical interval. Repetitive transcranial magnetic stimulation produced representational neglect-like symptoms in number bisection when applied over right posterior parietal cortex (right PPC). Repetitive TMS over right PPC shifted the perceived midpoint of the numerical interval significantly to the right while occipital TMS had no effect on bisection performance. Our study therefore provides further evidence that subjects use spatial representations, perhaps akin to a mental number line, in basic numerical processing tasks. Furthermore, we showed that the right posterior parietal cortex is crucially involved in spatial representation of numbers.

  8. Some surprising findings on the involvement of the parietal lobe in human memory.

    Science.gov (United States)

    Olson, Ingrid R; Berryhill, Marian

    2009-02-01

    The posterior parietal lobe is known to play some role in a far-flung list of mental processes: linking vision to action (saccadic eye movements, reaching, grasping), attending to visual space, numerical calculation, and mental rotation. Here, we review findings from humans and monkeys that illuminate an untraditional function of this region: memory. Our review draws on neuroimaging findings that have repeatedly identified parietal lobe activations associated with short-term or working memory and episodic memory. We also discuss recent neuropsychological findings showing that individuals with parietal lobe damage exhibit both working memory and long-term memory deficits. These deficits are not ubiquitous; they are only evident under certain retrieval demands. Our review elaborates on these findings and evaluates various theories about the mechanistic role of the posterior parietal lobe in memory. The available data point towards the conclusion that the posterior parietal lobe plays an important role in memory retrieval irrespective of elapsed time. However, the available data do not support simple dichotomies such as recall versus recognition, working versus long-term memory. We conclude by formalizing several open questions that are intended to encourage future research in this rapidly developing area of memory research.

  9. A selective working memory impairment after transcranial direct current stimulation to the right parietal lobe.

    Science.gov (United States)

    Berryhill, Marian E; Wencil, Elaine B; Branch Coslett, H; Olson, Ingrid R

    2010-08-02

    The role of the posterior parietal cortex in working memory (WM) is poorly understood. We previously found that patients with parietal lobe damage exhibited a selective WM impairment on recognition but not recall tasks. We hypothesized that this dissociation reflected strategic differences in the utilization of attention. One concern was that these findings, and our subsequent interpretation, would not generalize to normal populations because of the patients' older age, progressive disease processes, and/or possible brain reorganization following injury. To test whether our findings extended to a normal population we applied transcranial direct current stimulation (tDCS) to right inferior parietal cortex. tDCS is a technique by which low electric current applied to the scalp modulates the resting potentials of underlying neural populations and can be used to test structure-function relationships. Eleven normal young adults received cathodal, anodal, or sham stimulation over right inferior posterior parietal cortex and then performed separate blocks of an object WM task probed by recall or recognition. The results showed that cathodal stimulation selectively impaired WM on recognition trials. These data replicate and extend our previous findings of preserved WM recall and impaired WM recognition in patients with parietal lobe lesions. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

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

    African Journals Online (AJOL)

    Bilateral, posterior parietal polymicrogyria as part of speech therapy work-up. ... units to make the diagnosis of bilateral posterior parietal polymicrogyria in a child with speech pathology. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  11. Social distance evaluation in human parietal cortex.

    Science.gov (United States)

    Yamakawa, Yoshinori; Kanai, Ryota; Matsumura, Michikazu; Naito, Eiichi

    2009-01-01

    Across cultures, social relationships are often thought of, described, and acted out in terms of physical space (e.g. "close friends" "high lord"). Does this cognitive mapping of social concepts arise from shared brain resources for processing social and physical relationships? Using fMRI, we found that the tasks of evaluating social compatibility and of evaluating physical distances engage a common brain substrate in the parietal cortex. The present study shows the possibility of an analytic brain mechanism to process and represent complex networks of social relationships. Given parietal cortex's known role in constructing egocentric maps of physical space, our present findings may help to explain the linguistic, psychological and behavioural links between social and physical space.

  12. Parietal wall endometriosis: a rare case report

    Directory of Open Access Journals (Sweden)

    Mahija Sahu

    2015-04-01

    Full Text Available A 28 year old P2L1 with one previous cesarean presented with cyclical pain in periumblical area just below umbilicus for 1 year with USG finding suggestive of parietal wall endometriosis planned for surgery on her 2nd day of menstruation. She underwent diagnostic laparoscopy with complete excision of endometrioma. Diagnostic laparoscopy showed no evidence of endometrioma in the pelvic cavity except for omental adhesion at parietal wall endometrioma site, adhesiolysis of omentum, mesh repair of rectus sheath defect done. She is followed up for last 3 cycles post-operative and has no cyclical pain further. [Int J Reprod Contracept Obstet Gynecol 2015; 4(2.000: 524-526

  13. Deficits of Motor Intention following Parietal Lesions

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    Christopher L. Gore

    2002-01-01

    Full Text Available Patients with lesions to the right parietal lobe were tested on their ability to reach to targets, or to respond verbally to targets. The targets occurred at the same two spatial locations -- to the left and right of the patient—with the task being cued by the color of the target. Patients were able to perform both tasks separately rapidly and without error. However, when the two tasks were interleaved, they had difficulty making a response in the left (contralesional field when this was different to a response that they had just made. These results suggest that lesions to the parietal cortex may cause a deficit in the coding for motor intention, as well as attention in the contralesional field.

  14. Somatosensory-motor adaptation of orofacial actions in posterior parietal and ventral premotor cortices.

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    Krystyna Grabski

    Full Text Available Recent studies have provided evidence for sensory-motor adaptive changes and action goal coding of visually guided manual action in premotor and posterior parietal cortices. To extend these results to orofacial actions, devoid of auditory and visual feedback, we used a repetition suppression paradigm while measuring neural activity with functional magnetic resonance imaging during repeated intransitive and silent lip, jaw and tongue movements. In the motor domain, this paradigm refers to decreased activity in specific neural populations due to repeated motor acts and has been proposed to reflect sensory-motor adaptation. Orofacial movements activated a set of largely overlapping, common brain areas forming a core neural network classically involved in orofacial motor control. Crucially, suppressed neural responses during repeated orofacial actions were specifically observed in the left ventral premotor cortex, the intraparietal sulcus, the inferior parietal lobule and the superior parietal lobule. Since no visual and auditory feedback were provided during orofacial actions, these results suggest somatosensory-motor adaptive control of intransitive and silent orofacial actions in these premotor and parietal regions.

  15. Discrete object representation, attention switching, and task difficulty in the parietal lobe.

    Science.gov (United States)

    Cusack, Rhodri; Mitchell, Daniel J; Duncan, John

    2010-01-01

    An important component of perception, attention, and memory is the structuring of information into subsets ("objects"), which allows some parts to be considered together but kept separate from others. Portions of the posterior parietal lobe respond proportionally to the number of objects in the scope of attention and short-term memory, up to a capacity limit of around four, suggesting they have a role in this important process. This study investigates the relationship of discrete object representation to other parietal functions. Two experiments and two supplementary analyses were conducted to evaluate responsivity in parietal regions to the number of objects, the number of spatial locations, attention switching, and general task difficulty. Using transparent motion, it was found that a posterior and inferior parietal response to multiple objects persists even in the absence of a change in visual extent or the number of spatial locations. In a monitoring task, it was found that attention switching (or task difficulty) and object representation have distinct neural signatures, with the former showing greater recruitment of an anterior and lateral intraparietal sulcus (IPS) region, but the latter in a posterior and lateral region. A dissociation was also seen between selectivity for object load across tasks in the inferior IPS and feature or object-related memory load in the superior IPS.

  16. Optic ataxia: from Balint’s syndrome to the parietal reach region

    Science.gov (United States)

    Andersen, Richard A.; Andersen, Kristen N.; Hwang, EunJung; Hauschild, Markus

    2014-01-01

    Optic ataxia is a high order deficit in reaching to visual goals that occurs with posterior parietal cortex (PPC) lesions. It is a component of Balint’s syndrome that also includes attentional and gaze disorders. Aspects of optic ataxia are misreaching in the contralesional visual field, difficulty preshaping the hand for grasping, and an inability to correct reaches online. Recent research in non-human primates (NHPs) suggests that many aspects of Balint’s syndrome and optic ataxia are a result of damage to specific functional modules for reaching, saccades, grasp, attention, and state estimation. The deficits from large lesions in humans are likely composite effects from damage to combinations of these functional modules. Interactions between these modules, either within posterior parietal cortex or downstream within frontal cortex, may account for more complex behaviors such as hand-eye coordination and reach-to-grasp. PMID:24607223

  17. Working memory load influences perceptual ambiguity by competing for fronto-parietal attentional resources.

    Science.gov (United States)

    Intaitė, Monika; Duarte, João Valente; Castelo-Branco, Miguel

    2016-11-01

    A visual stimulus is defined as ambiguous when observers perceive it as having at least two distinct and spontaneously alternating interpretations. Neuroimaging studies suggest an involvement of a right fronto-parietal network regulating the balance between stable percepts and the triggering of alternative interpretations. As spontaneous perceptual reversals may occur even in the absence of attention to these stimuli, we investigated neural activity patterns in response to perceptual changes of ambiguous Necker cube under different amounts of working memory load using a dual-task design. We hypothesized that the same regions that process working memory load are involved in perceptual switching and confirmed the prediction that perceptual reversals led to fMRI responses that linearly depended on load. Accordingly, posterior Superior Parietal Lobule, anterior Prefrontal and Dorsolateral Prefrontal cortices exhibited differential BOLD signal changes in response to perceptual reversals under working memory load. Our results also suggest that the posterior Superior Parietal Lobule may be directly involved in the emergence of perceptual reversals, given that it specifically reflects both perceptual versus real changes and load levels. The anterior Prefrontal and Dorsolateral Prefrontal cortices, showing a significant interaction between reversal levels and load, might subserve a modulatory role in such reversals, in a mirror symmetric way: in the former activation is suppressed by the highest loads, and in the latter deactivation is reduced by highest loads, suggesting a more direct role of the aPFC in reversal generation.

  18. Atypical parietal lobe activity to subliminal faces in youth with a family history of alcoholism.

    Science.gov (United States)

    Peraza, Jennifer; Cservenka, Anita; Herting, Megan M; Nagel, Bonnie J

    2015-03-01

    Adults with alcohol use disorders (AUDs) show different behavioral and neurological functioning during emotional processing tasks from healthy controls. Adults with a family history (FHP) of AUD also show different activation in limbic brain areas, such as the amygdala. However, it is unclear if this pattern exists during adolescence before any episodes of heavy alcohol use. We hypothesized that the amygdalar response to subliminally-presented fearful faces would be reduced in FHP adolescents compared to peers who were family history negative (FHN) for AUD. An adapted Masked Faces paradigm was used to examine blood oxygen level-dependent response to subliminal fearful vs. neutral faces in 14 FHP (6 females, 8 males) and 15 FHN (6 females, 9 males) youth, ages 11-15 years. Both FHP and FHN youth had no history of heavy alcohol consumption. A significant difference was seen between groups in the left superior parietal lobule FHN youth showed deactivation to fearful and neutral masked faces compared to baseline, whereas FHP youth showed deactivation only to fearful masked faces. No significant differences in amygdalar activation were seen between groups. The left superior parietal lobule is part of the fronto-parietal network, which has been implicated in attentional control. Lack of reduced neural activity to neutral faces among FHP youth may represent differences in suppressing attention networks to less salient emotional stimuli, or perhaps, a higher threshold of saliency for emotional stimuli among at-risk youth.

  19. Morbidity profile following aggressive resection of parietal lobe gliomas.

    Science.gov (United States)

    Sanai, Nader; Martino, Juan; Berger, Mitchel S

    2012-06-01

    The impact of parietal lobe gliomas is typically studied in the context of parietal lobe syndromes. However, critical language pathways traverse the parietal lobe and are susceptible during tumor resection. The authors of this study reviewed their experience with parietal gliomas to characterize the impact of resection and the morbidity associated with language. The study population included adults who had undergone resection of parietal gliomas of all grades. Tumor location was identified according to a proposed classification system for parietal region gliomas. Low- and high-grade tumors were volumetrically analyzed using FLAIR and T1-weighted contrast-enhanced MR imaging. One hundred nineteen patients with parietal gliomas were identified--34 with low-grade gliomas and 85 with high-grade gliomas. The median patient age was 45 years, and most patients (53) presented with seizures, whereas only 4 patients had an appreciable parietal lobe syndrome. The median preoperative tumor volume was 31.3 cm(3), the median extent of resection was 96%, and the median postoperative tumor volume was 0.9 cm(3). Surprisingly, the most common early postoperative neurological deficit was dysphasia (16 patients), not weakness (12 patients), sensory deficits (14 patients), or parietal lobe syndrome (10 patients). A proposed parietal glioma classification system, based on surgical anatomy, was predictive of language deficits. This is the largest reported experience with parietal lobe gliomas. The findings suggested that parietal language pathways are compromised at a surprisingly high rate. The proposed parietal glioma classification system is predictive of postoperative morbidity associated with language and can assist with preoperative planning. Taken together, these data emphasize the value of identifying language pathways when operating within the parietal lobe.

  20. Theta and Alpha Oscillations during the Retention Period of Working Memory by rTMS Stimulating the Parietal Lobe

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    Song Li

    2017-09-01

    Full Text Available Studies on repetitive transcranial magnetic stimulation (rTMS have shown that stimulating the parietal lobe, which plays a role in memory storage, can enhance performance during the “retention” process of working memory (WM. However, the mechanism of rTMS effect during this phase is still unclear. In this study, we stimulated the superior parietal lobe (SPL using 5-Hz rTMS in 26 participants and recorded electroencephalography (EEG while they performed a delayed-recognition WM task. The analyses included the comparisons of event-related spectral perturbation (ERSP value variations in theta (4–7 Hz and alpha (8–14 Hz band frequencies between conditions (rTMS vs. sham, as well as the correlations between different brain areas. Following rTMS, the ERSP values of theta-band oscillations were significantly increased in the parietal and occipital-parietal brain areas (P < 0.05*, whereas the ERSP values of alpha-band oscillations were significantly decreased in the parietal area (P < 0.05*. The ERSP value variations of theta-band oscillations between the two conditions in the left parietal and left prefrontal areas were positively correlated with the response time (RT variations (by using rTMS, the more subject RT decreased, the more ERSP value of theta oscillation increased. The ERSP value variations of alpha-band oscillations in the left parietal and bilateral prefrontal areas were negatively correlated with RT variations (by using rTMS, the more RT of the subject decreased, the more ERSP value of alpha oscillation decreased. Inter-sites phase synchronization of theta-band EEG between the left parietal and left prefrontal areas, as well as alpha-band EEG between the left parietal and bilateral prefrontal areas were enhanced by rTMS. These results indicated that activities of both parietal and prefrontal areas were required for information storage, and these activities were related to the behavioral responses. Moreover, the connectivity

  1. Cortical and subcortical anatomy of chronic spatial neglect following vascular damage

    Directory of Open Access Journals (Sweden)

    Schnider Armin

    2008-09-01

    Full Text Available Abstract Background The role of the inferior parietal lobule (IPL and superior temporal gyrus (STG or subcortical pathways as possible anatomical correlates of spatial neglect is currently intensely discussed. Some of the conflicting results might have arisen because patients were examined in the acute stage of disease. Methods We examined the anatomical basis of spatial neglect in a sample of patients examined in the post-acute stage following right-hemispheric vascular brain damage. Lesions of 28 patients with chronic spatial neglect were contrasted to lesions of 22 control patients without neglect using lesion subtraction techniques and voxel-wise comparisons. Results The comparisons identified the temporo-parietal junction (TPJ with underlying white matter, the supramarginal gyrus, the posterior STG, and the insula as brain regions damaged significantly more often in neglect compared to non-neglect patients. In a subgroup of neglect patients showing particularly large cancellation bias together with small errors on line bisection damage was prevalent deep in the frontal lobe while damage of patients with the reverse pattern was located in the white matter of the TPJ. Conclusion Considering our results and the findings of previous studies, spatial neglect appears to be associated with a network of regions involving the TPJ, inferior IPL, posterior STG, the insular cortex, and posterior-frontal projections. Frontal structures or projections may be of particular relevance for spatial exploration, while the IPL may be important for object-based attention as required for line bisection.

  2. The ‘when’ pathway of the right parietal lobe

    Science.gov (United States)

    Battelli, Lorella; Pascual-Leone, Alvaro; Cavanagh, Patrick

    2013-01-01

    The order of events, whether two events are seen as simultaneous or successive, sets the stage for the moment-to-moment interpretation of the visual world. Evidence from patients who have lesions to the parietal lobes and transcranial magnetic stimulation studies in normal subjects suggest that the right inferior parietal lobe underlies this analysis of event timing. Judgment of temporal order, simultaneity and high-level motion are all compromised following right parietal lesions and degraded after transcranial magnetic stimulation over the right parietal but not elsewhere. The results suggest that the right parietal lobe serves as part of a when pathway for both visual fields. We propose that the disruption of this mechanism is the underlying cause of a wide range of seemingly unrelated tasks being impaired in right parietal patients. PMID:17379569

  3. Parietal cortex and representation of the mental Self

    DEFF Research Database (Denmark)

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

    2004-01-01

    differential activity in medial prefrontal and medial parietal cortices. With positron-emission tomography, we here show that these medial regions are functionally connected and interact with lateral regions that are activated according to the degree of self-reference. During retrieval of previous judgments...... of Oneself, Best Friend, and the Danish Queen, activation increased in the left lateral temporal cortex and decreased in the right inferior parietal region with decreasing self-reference. Functionally, the former region was preferentially connected to medial prefrontal cortex, the latter to medial parietal....... 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...

  4. Is the parietal lobe necessary for recollection in humans?

    Science.gov (United States)

    Simons, Jon S; Peers, Polly V; Hwang, David Y; Ally, Brandon A; Fletcher, Paul C; Budson, Andrew E

    2008-03-07

    An intriguing puzzle in cognitive neuroscience over recent years has been the common observation of parietal lobe activation in functional neuroimaging studies during the performance of human memory tasks. These findings have surprised scientists and clinicians because they challenge decades of established thinking that the parietal lobe does not support memory function. However, direct empirical investigation of whether circumscribed parietal lobe lesions might indeed be associated with human memory impairment has been lacking. Here we confirm using functional magnetic resonance imaging that significant parietal lobe activation is observed in healthy volunteers during a task assessing recollection of the context in which events previously occurred. However, patients with parietal lobe lesions that overlap closely with the regions activated in the healthy volunteers nevertheless exhibit normal performance on the same recollection task. Thus, although the processes subserved by the human parietal lobe appear to be recruited to support memory function, they are not a necessary requirement for accurate remembering to occur.

  5. A focus on parietal cells as a renewing cell population

    Institute of Scientific and Technical Information of China (English)

    Sherif; M; Karam

    2010-01-01

    The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3Hthymidine radioautography in combination with electron microscopy, it was possible to demonstrate that parietal cells belong to a continuously renewing epithelial cell lineage. In the gastric glands, stem cells anchored in the isthmus region are responsible for the production of parietal cells...

  6. Distinct contributions by frontal and parietal cortices support working memory.

    Science.gov (United States)

    Mackey, Wayne E; Curtis, Clayton E

    2017-07-21

    Although subregions of frontal and parietal cortex both contribute and coordinate to support working memory (WM) functions, their distinct contributions remain elusive. Here, we demonstrate that perturbations to topographically organized human frontal and parietal cortex during WM maintenance cause distinct but systematic distortions in WM. The nature of these distortions supports theories positing that parietal cortex mainly codes for retrospective sensory information, while frontal cortex codes for prospective action.

  7. Sex Differences in Parietal Lobe Structure and Development

    OpenAIRE

    Salinas, Joel; Mills, Elizabeth D.; Conrad, Amy L.; Koscik, Timothy; Andreasen, Nancy C; Nopoulos, Peg

    2012-01-01

    Structural MRI studies provide evidence for sex differences in the human brain. Differences in surface area and the proportion of gray to white matter volume are observed, particularly in the parietal lobe. To our knowledge, there are no studies examining sex differences of parietal lobe structure in younger populations or in the context of development. The current study evaluated sex difference in the structure of the parietal lobe in children (7-17 years of age). Also, by adding the cohort ...

  8. The ‘when’ pathway of the right parietal lobe

    OpenAIRE

    Battelli, Lorella; Pascual-Leone, Alvaro; Cavanagh, Patrick

    2007-01-01

    The order of events, whether two events are seen as simultaneous or successive, sets the stage for the moment-to-moment interpretation of the visual world. Evidence from patients who have lesions to the parietal lobes and transcranial magnetic stimulation studies in normal subjects suggest that the right inferior parietal lobe underlies this analysis of event timing. Judgment of temporal order, simultaneity and high-level motion are all compromised following right parietal lesions and degrade...

  9. Callosal alien hand sign following a right parietal lobe infarction.

    Science.gov (United States)

    Kim, Young-Do; Lee, Eek-Sung; Lee, Kwang-Soo; Kim, Joong-Seok

    2010-06-01

    Callosal alien hand syndrome is characterized primarily by intermanual conflict and is associated with an anterior callosal lesion. We report a patient who presented with topographical disorientation and the callosal type alien hand sign. An MRI of the brain showed a right parietal lobe infarction. This is a rare example of callosal alien hand sign associated with a right parietal lesion. The right parietal lobe appeared to be responsible for the callosal hand sign in this patient, possibly due to interference with peristriate outflow pathways toward the parietal zones, where visual somatosensory interactions are likely to occur. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Alzheimer's disease: the downside of a highly evolved parietal lobe?

    Science.gov (United States)

    Bruner, Emiliano; Jacobs, Heidi I L

    2013-01-01

    Clinical grade Alzheimer's disease (AD) is only described in humans. Recent imaging studies in early AD patients showed that the parietal areas display the most prominent metabolic impairments. So far, neuroimaging studies have not been able to explain why the medial parietal regions possess this hub characteristic in AD. Paleoneurological and neuroanatomical studies suggest that our species, Homo sapiens, has a unique and derived organization of the parietal areas, which are involved in higher cognitive functions. Combining evidence from neuroimaging, paleontology, and comparative anatomy, we suggest that the vulnerability of the parietal lobe to neurodegenerative processes may be associated with the origin of our species. The species-specific parietal morphology in modern humans largely influenced the brain spatial organization, and it involved changes in vascularization and energy management, which may underlie the sensitivity of these areas to metabolic impairment. Metabolic constraints and anatomical evolutionary changes in the medial parietal regions of modern humans may be important in early AD onset. Taking into account the species-specific adaptations of the modern human parietal areas and their association with AD, we hypothesize that AD can be the evolutionary drawback of the specialized structure of our parietal lobes. The cognitive advantage is associated with increased sensitivity to neurodegenerative processes which, being limited to the post-reproductive period, have a minor effect on the overall genetic fitness. The changes of energy requirements associated with form and size variations at the parietal areas may support the hypothesis of AD as a metabolic syndrome.

  11. Muscarinic responses of gastric parietal cells

    Energy Technology Data Exchange (ETDEWEB)

    Wilkes, J.M.; Kajimura, M.; Scott, D.R.; Hersey, S.J.; Sachs, G. (Department of Medicine, University of California, Los Angeles (United States))

    1991-06-01

    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.

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

    Science.gov (United States)

    Tanaka, Satoshi; Ikeda, Hanako; Kasahara, Kazumi; Kato, Ryo; Tsubomi, Hiroyuki; Sugawara, Sho K; Mori, Makoto; Hanakawa, Takashi; Sadato, Norihiro; Honda, Manabu; Watanabe, Katsumi

    2013-01-01

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

  13. Activation in the Right Inferior Parietal Lobule Reflects the Representation of Musical Structure beyond Simple Pitch Discrimination

    Science.gov (United States)

    Royal, Isabelle; Vuvan, Dominique T.; Zendel, Benjamin Rich; Robitaille, Nicolas; Schönwiesner, Marc; Peretz, Isabelle

    2016-01-01

    Pitch discrimination tasks typically engage the superior temporal gyrus and the right inferior frontal gyrus. It is currently unclear whether these regions are equally involved in the processing of incongruous notes in melodies, which requires the representation of musical structure (tonality) in addition to pitch discrimination. To this aim, 14 participants completed two tasks while undergoing functional magnetic resonance imaging, one in which they had to identify a pitch change in a series of non-melodic repeating tones and a second in which they had to identify an incongruous note in a tonal melody. In both tasks, the deviants activated the right superior temporal gyrus. A contrast between deviants in the melodic task and deviants in the non-melodic task (melodic > non-melodic) revealed additional activity in the right inferior parietal lobule. Activation in the inferior parietal lobule likely represents processes related to the maintenance of tonal pitch structure in working memory during pitch discrimination. PMID:27195523

  14. The superior transvelar approach to the fourth ventricle and brainstem.

    Science.gov (United States)

    Ezer, Haim; Banerjee, Anirban Deep; Bollam, Papireddy; Guthikonda, Bharat; Nanda, Anil

    2012-06-01

    Objective The superior transvelar approach is used to access pathologies located in the fourth ventricle and brainstem. The surgical path is below the venous structures, through the superior medullary velum. Following splitting the tentorial edge, near the tentorial apex, the superior medullary velum is split in the cerebello-mesencephalic fissure. Using the supracerebellar infratentorial, transtentorial or parietal interhemispheric routes, the superior medullary velum is approached. Splitting this velum provides a detailed view of the fourth ventricle and its floor. Materials and Methods A total of 10 formalin-fixed specimens were dissected in a stepwise manner to simulate the superior transvelar approach to the fourth ventricle. The exposure gained the distance from the craniotomy site and the ease of access was assessed for each of the routes. We also present an illustrative case, operated by the senior author (AN). Results The superior transvelar approach provides access to the entire length of the fourth ventricle floor, from the aqueduct to the obex, when using the parietal interhemispheric route. In addition, this approach provides access to the entire width of the floor of the fourth ventricle; however, this requires retracting the superior cerebellar peduncle. Using the supracerebellar infratentorial route gives a limited exposure of the superior part of the fourth ventricle. The occipital interhemispheric route is a compromise between these two. Conclusion The superior transvelar approach to the fourth ventricle provides a route for approaching the fourth ventricle from above. This approach does not require opening the posterior fossa in the traditional way, and provides a reasonable alternative for accessing the superior fourth ventricle.

  15. Bilateral fronto-parietal integrity in young chronic cigarette smokers: a diffusion tensor imaging study.

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    Yanhui Liao

    Full Text Available BACKGROUND: Cigarette smoking continues to be the leading cause of preventable morbidity and mortality in China and other countries. Previous studies have demonstrated gray matter loss in chronic smokers. However, only a few studies assessed the changes of white matter integrity in this group. Based on those previous reports of alterations in white matter integrity in smokers, the aim of this study was to examine the alteration of white matter integrity in a large, well-matched sample of chronic smokers and non-smokers. METHODOLOGY/PRINCIPAL FINDINGS: Using in vivo diffusion tensor imaging (DTI to measure the differences of whole-brain white matter integrity between 44 chronic smoking subjects (mean age, 28.0±5.6 years and 44 healthy age- and sex-matched comparison non-smoking volunteers (mean age, 26.3±5.8 years. DTI was performed on a 3-Tesla Siemens scanner (Allegra; Siemens Medical System. The data revealed that smokers had higher fractional anisotropy (FA than healthy non-smokers in almost symmetrically bilateral fronto-parietal tracts consisting of a major white matter pathway, the superior longitudinal fasciculus (SLF. CONCLUSION/SIGNIFICANCE: We found the almost symmetrically bilateral fronto-parietal whiter matter changes in a relatively large sample of chronic smokers. These findings support the hypothesis that chronic cigarette smoking involves alterations of bilateral fronto-parietal connectivity.

  16. Tool-use practice induces changes in intrinsic functional connectivity of parietal areas

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    Kwangsun eYoo

    2013-02-01

    Full Text Available Intrinsic functional connectivity from resting state functional magnetic resonance imaging (rsfMRI has increasingly received attention as a possible predictor of cognitive function and performance. In this study, we investigated the influence of practicing skillful tool manipulation on intrinsic functional connectivity in the resting brain. Acquisition of tool-use skill has two aspects such as formation of motor representation for skillful manipulation and acquisition of the tool concept. To dissociate these two processes, we chose chopsticks-handling with the non-dominant hand. Because participants were already adept at chopsticks-handling with their dominant hand, practice with the non-dominant hand involved only acquiring the skill for tool manipulation with existing knowledge. Eight young participants practiced chopsticks-handling with their non-dominant hand for 8 weeks. They underwent fMRI sessions before and after the practice. As a result, functional connectivity among tool-use-related regions of the brain decreased after practice. We found decreased functional connectivity centered on parietal areas, mainly the supramarginal gyrus and superior parietal lobule and additionally between the primary sensorimotor area and cerebellum. These results suggest that the parietal lobe and cerebellum purely mediate motor learning for skillful tool-use. This decreased functional connectivity may represent increased efficiency of functional network.

  17. The Role of Human Parietal Cortex in Attention Networks

    Science.gov (United States)

    Han, Shihui; Jiang, Yi; Gu, Hua; Rao, Hengyi; Mao, Lihua; Cui, Yong; Zhai, Renyou

    2004-01-01

    The parietal cortex has been proposed as part of the neural network for guiding spatial attention. However, it is unclear to what degree the parietal cortex contributes to the attentional modulations of activities of the visual cortex and the engagement of the frontal cortex in the attention network. We recorded behavioural performance and…

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

    Science.gov (United States)

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

    2012-11-01

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

  19. Parietal lobe epilepsy: the great imitator among focal epilepsies.

    Science.gov (United States)

    Ristić, Aleksandar J; Alexopoulos, Andreas V; So, Norman; Wong, Chong; Najm, Imad M

    2012-03-01

    Comprising large areas of association cortex, the parietal lobe is part of an extensive synaptic network elaborately intertwined with other brain regions. We hypothesize that such widespread projections are responsible for producing inaccurate localisation readings on scalp EEG and clinical semiology in patients with parietal lobe epilepsies, as opposed to frontal or temporal lobe epilepsies. Our study included 50 patients with pharmacoresistant focal epilepsy, who were subsequently rendered seizure-free for ≥12 months (median: 23 months) following resections limited to the frontal (n=17), temporal (n=17), or parietal (n=16) lobes. Interictal and ictal EEG data with accompanying seizure video recordings were extracted from archived files of scalp video-EEG monitoring. Two blinded raters independently reviewed the EEG according to predetermined criteria. Videos of seizures were then observed, as raters formulated their final electroclinical impression (ECI), identifying patients' abnormal neuronal activities with parietal, temporal, and frontal lobe epilepsy, or unspecified localisation. Groups did not differ significantly in demographics, age at epilepsy onset, or presence of MRI abnormalities. Interictal discharges in parietal lobe epilepsy showed the greatest magnitude of scatter outside the lobe of origin; the majority of patients with parietal lobe epilepsy had more than one spike population (pparietal lobe epilepsy cases (p=0.024). Whenever raters confidently limited their ECI to one lobar subtype, overall accuracy was excellent. Lobar classifications by ECI were highly accurate for temporal lobe epilepsy, vacillating in frontal lobe epilepsy, and least accurate in parietal lobe epilepsy subjects. Scalp EEG readings of parietal lobe epilepsy patients showed a more variable scatter of interictal discharges and a lower localisation value of ictal recordings compared to temporal and frontal lobe epilepsy subjects, suggesting an increased likelihood of

  20. Individual structural differences in left inferior parietal area are associated with schoolchildrens’ arithmetic scores

    Directory of Open Access Journals (Sweden)

    Yongxin eLi

    2013-12-01

    Full Text Available Arithmetic skill is of critical importance for academic achievement, professional success and everyday life, and childhood is the key period to acquire this skill. Neuroimaging studies have identified that left parietal regions are a key neural substrate for representing arithmetic skill. Although the relationship between functional brain activity in left parietal regions and arithmetic skill has been studied in detail, it remains unclear about the relationship between arithmetic achievement and structural properties in left inferior parietal area in schoolchildren. The current study employed a combination of voxel-based morphometry (VBM for high-resolution T1-weighted images and fiber tracking on diffusion tensor imaging (DTI to examine the relationship between structural properties in the inferior parietal area and arithmetic achievement in 10-year-old schoolchildren. VBM of the T1-weighted images revealed that individual differences in arithmetic scores were significantly and positively correlated with the grey matter (GM volume in the left intraparietal sulcus (IPS. Fiber tracking analysis revealed that the forceps major, left superior longitudinal fasciculus (SLF, bilateral inferior longitudinal fasciculus (ILF and inferior fronto-occipital fasciculus (IFOF were the primary pathways connecting the left IPS with other brain areas. Furthermore, the regression analysis of the probabilistic pathways revealed a significant and positive correlation between the fractional anisotropy (FA values in the left SLF, ILF and bilateral IFOF and arithmetic scores. The brain structure-behavior correlation analyses indicated that the GM volumes in the left IPS and the FA values in the tract pathways connecting left IPS were both related to children’s arithmetic achievement. The present findings provide evidence that individual structural differences in the left IPS are associated with arithmetic scores in schoolchildren.

  1. Caracterización del injerto parietal

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    José Manuel Díaz Fernández

    1996-12-01

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

  2. Aberrant parietal cortex developmental trajectories in girls with Turner syndrome and related visual-spatial cognitive development: a preliminary study.

    Science.gov (United States)

    Green, Tamar; Chromik, Lindsay C; Mazaika, Paul K; Fierro, Kyle; Raman, Mira M; Lazzeroni, Laura C; Hong, David S; Reiss, Allan L

    2014-09-01

    Turner syndrome (TS) arises from partial or complete absence of the X-chromosome in females. Girls with TS show deficits in visual-spatial skills as well as reduced brain volume and surface area in the parietal cortex which supports these cognitive functions. Thus, measuring the developmental trajectory of the parietal cortex and the associated visual-spatial cognition in TS may provide novel insights into critical brain-behavior associations. In this longitudinal study, we acquired structural MRI data and assessed visual-spatial skills in 16 (age: 8.23 ± 2.5) girls with TS and 13 age-matched controls over two time-points. Gray and white matter volume, surface area and cortical thickness were calculated from surfaced based segmentation of bilateral parietal cortices, and the NEPSY Arrows subtest was used to assess visual-spatial ability. Volumetric and cognitive scalars were modeled to obtain estimates of age-related change. The results show aberrant growth of white matter volume (P = 0.011, corrected) and surface area (P = 0.036, corrected) of the left superior parietal regions during childhood in girls with TS. Other parietal sub-regions were significantly smaller in girls with TS at both time-points but did not show different growth trajectories relative to controls. Furthermore, we found that visual-spatial skills showed a widening deficit for girls with TS relative to controls (P = 0.003). Young girls with TS demonstrate an aberrant trajectory of parietal cortical and cognitive development during childhood. Elucidating aberrant neurodevelopmental trajectories in this population is critical for determining specific stages of brain maturation that are particularly dependent on TS-related genetic and hormonal factors. © 2014 Wiley Periodicals, Inc.

  3. Navigating actions through the rodent parietal cortex

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    Jonathan R. Whitlock

    2014-05-01

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

  4. 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.

  5. Abnormal Parietal Function in Conversion Paresis

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

    2011-01-01

    The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study 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. PMID:22039428

  6. The temporo-parietal junction contributes to global gestalt perception – evidence from studies in chess experts

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    Johannes eRennig

    2013-08-01

    Full Text Available In a recent neuroimaging study the comparison of intact versus disturbed perception of global gestalt indicated a significant role of the temporo-parietal junction (TPJ in the intact perception of global gestalt (Huberle and Karnath, 2012. This location corresponded well with the areas known to be damaged or impaired in patients with simultanagnosia after stroke or due to neurodegenerative diseases. It was concluded that the TPJ plays an important role in the integration of individual items to a holistic percept. Thus, increased BOLD signals should be found in this region whenever a task calls for the integration of multiple visual items. Behavioral experiments in chess experts suggested that their superior skills in comparison to chess novices are partly based on fast holistic processing of chess positions with multiple pieces. We thus analyzed BOLD data from four fMRI studies that compared chess experts with chess novices during the presentation of complex chess-related visual stimuli (Bilalić et al., 2011a, 2010, 2011b, 2012. Three regions of interests were defined by significant TPJ clusters in the abovementioned study of global gestalt perception (Huberle and Karnath, 2012 and BOLD signal amplitudes in these regions were compared between chess experts and novices. These cross-paradigm ROI analyses revealed higher signals at the TPJ in chess experts in comparison to novices during presentations of complex chess positions. This difference was consistent across the different tasks in five independent experiments. Our results confirm the assumption that the TPJ region identified in previous work on global gestalt perception plays an important role in the processing of complex visual stimulus configurations.

  7. The temporo-parietal junction contributes to global gestalt perception—evidence from studies in chess experts

    Science.gov (United States)

    Rennig, Johannes; Bilalić, Merim; Huberle, Elisabeth; Karnath, Hans-Otto; Himmelbach, Marc

    2013-01-01

    In a recent neuroimaging study the comparison of intact vs. disturbed perception of global gestalt indicated a significant role of the temporo-parietal junction (TPJ) in the intact perception of global gestalt (Huberle and Karnath, 2012). This location corresponded well with the areas known to be damaged or impaired in patients with simultanagnosia after stroke or due to neurodegenerative diseases. It was concluded that the TPJ plays an important role in the integration of individual items to a holistic percept. Thus, increased BOLD signals should be found in this region whenever a task calls for the integration of multiple visual items. Behavioral experiments in chess experts suggested that their superior skills in comparison to chess novices are partly based on fast holistic processing of chess positions with multiple pieces. We thus analyzed BOLD data from four fMRI studies that compared chess experts with chess novices during the presentation of complex chess-related visual stimuli (Bilalić et al., 2010, 2011a,b, 2012). Three regions of interests were defined by significant TPJ clusters in the abovementioned study of global gestalt perception (Huberle and Karnath, 2012) and BOLD signal amplitudes in these regions were compared between chess experts and novices. These cross-paradigm ROI analyses revealed higher signals at the TPJ in chess experts in comparison to novices during presentations of complex chess positions. This difference was consistent across the different tasks in five independent experiments. Our results confirm the assumption that the TPJ region identified in previous work on global gestalt perception plays an important role in the processing of complex visual stimulus configurations. PMID:24009574

  8. The temporo-parietal junction contributes to global gestalt perception-evidence from studies in chess experts.

    Science.gov (United States)

    Rennig, Johannes; Bilalić, Merim; Huberle, Elisabeth; Karnath, Hans-Otto; Himmelbach, Marc

    2013-01-01

    In a recent neuroimaging study the comparison of intact vs. disturbed perception of global gestalt indicated a significant role of the temporo-parietal junction (TPJ) in the intact perception of global gestalt (Huberle and Karnath, 2012). This location corresponded well with the areas known to be damaged or impaired in patients with simultanagnosia after stroke or due to neurodegenerative diseases. It was concluded that the TPJ plays an important role in the integration of individual items to a holistic percept. Thus, increased BOLD signals should be found in this region whenever a task calls for the integration of multiple visual items. Behavioral experiments in chess experts suggested that their superior skills in comparison to chess novices are partly based on fast holistic processing of chess positions with multiple pieces. We thus analyzed BOLD data from four fMRI studies that compared chess experts with chess novices during the presentation of complex chess-related visual stimuli (Bilalić et al., 2010, 2011a,b, 2012). Three regions of interests were defined by significant TPJ clusters in the abovementioned study of global gestalt perception (Huberle and Karnath, 2012) and BOLD signal amplitudes in these regions were compared between chess experts and novices. These cross-paradigm ROI analyses revealed higher signals at the TPJ in chess experts in comparison to novices during presentations of complex chess positions. This difference was consistent across the different tasks in five independent experiments. Our results confirm the assumption that the TPJ region identified in previous work on global gestalt perception plays an important role in the processing of complex visual stimulus configurations.

  9. True Memory, False Memory, and Subjective Recollection Deficits after Focal Parietal Lobe Lesions

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    Drowos, David B.; Berryhill, Marian; André, Jessica M.; Olson, Ingrid R.

    2010-01-01

    Objective There is mounting evidence that the posterior parietal cortex (PPC) plays an important role in episodic memory. We previously found that patients with PPC damage exhibit retrieval-related episodic memory deficits. Our objective was to assess whether parietal lobe damage affects episodic memory on a different task: the Deese-Roediger-McDermott (DRM) false-memory paradigm. Method Two patients with bilateral PPC damage and matched controls were tested. In Experiment 1, the task was to remember words; in Experiment 2 the task was to remember pictures of common objects. Prior studies have shown that normal participants have high levels of false memory to words, low levels to pictures. Results The patients exhibited significantly lower levels of false memory to words. The patients' false memories were accompanied by reduced levels of recollection, as tested by a Remember/Know procedure. It is unlikely that a failure of gist processing accounts for these results, as patients accurately remembered thematic elements of short vignettes, but failed to remember details. These results support the view that portions of the PPC play a critical role in objective and subjective aspects of recollection. PMID:20604621

  10. Mapping the functional neuroanatomy of spatial neglect and human parietal lobe functions: progress and challenges.

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    Vuilleumier, Patrik

    2013-08-01

    Spatial neglect is generally defined by various deficits in processing information from one (e.g., left) side of space contralateral to focal (e.g., right) hemisphere damage. Although classically associated with parietal lobe functions, there is now compelling evidence that neglect can follow lesions in many different cortical and subcortical sites, suggesting a dysfunction in distributed brain networks. In addition, neglect is likely to result from a combination of distinct deficits that co-occur due to concomitant damage affecting juxtaposed brain areas and their connections, but the exact nature of core deficits and their neural substrates still remains unclear. The present review describes recent progress in identifying functional components of the neglect syndrome and relating them to distinct subregions of parietal cortex. A comprehensive understanding of spatial neglect will require a more precise definition of cognitive processes implicated in different behavioral manifestations, as well as meticulous mapping of these processes onto specific brain circuits, while taking into account functional changes in activity that may arise in structurally intact areas subsequent to damage in distant portions of the relevant networks. © 2013 New York Academy of Sciences.

  11. Damage to white matter pathways in subacute and chronic spatial neglect: a group study and 2 single-case studies with complete virtual "in vivo" tractography dissection.

    Science.gov (United States)

    Thiebaut de Schotten, Michel; Tomaiuolo, Francesco; Aiello, Marilena; Merola, Sheila; Silvetti, Massimo; Lecce, Francesca; Bartolomeo, Paolo; Doricchi, Fabrizio

    2014-03-01

    The exact anatomical localization of right hemisphere lesions that lead to left spatial neglect is still debated. The effect of confounding factors such as acute diaschisis and hypoperfusion, visual field defects, and lesion size may account for conflicting results that have been reported in the literature. Here, we present a comprehensive anatomical investigation of the gray- and white matter lesion correlates of left spatial neglect, which was run in a sample 58 patients with subacute or chronic vascular strokes in the territory of the right middle cerebral artery. Standard voxel-based correlates confirmed the role played by lesions in the posterior parietal cortex (supramarginal gyrus, angular gyrus, and temporal-parietal junction), in the frontal cortex (frontal eye field, middle and inferior frontal gyrus), and in the underlying parietal-frontal white matter. Using a new diffusion tensor imaging-based atlas of the human brain, we were able to run, for the first time, a detailed analysis of the lesion involvement of subcortical white matter pathways. The results of this analysis revealed that, among the different pathways linking parietal with frontal areas, damage to the second branch of the superior longitudinal fasciculus (SLF II) was the best predictor of left spatial neglect. The group study also revealed a subsample of patients with neglect due to focal lesion in the lateral-dorsal portion of the thalamus, which connects the premotor cortex with the inferior parietal lobule. The relevance of fronto-parietal disconnection was further supported by complete in vivo tractography dissection of white matter pathways in 2 patients, one with and the other without signs of neglect. These 2 patients were studied both in the acute phase and 1 year after stroke and were perfectly matched for age, handedness, stroke onset, lesion size, and for cortical lesion involvement. Taken together, the results of the present study support the hypothesis that anatomical

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

    Science.gov (United States)

    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.

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

    African Journals Online (AJOL)

    Congenital bilateral perisylvian syndrome (CBPS) was traditionally ... mental language disorder. Magnetic ... parietal polymicrogyria in a child with speech pathology. .... did not recognise food in the mouth, no tongue movement was observed.

  14. Gyri of the human parietal lobe: Volumes, spatial extents, automatic labelling, and probabilistic atlases.

    Science.gov (United States)

    Wild, Heather M; Heckemann, Rolf A; Studholme, Colin; Hammers, Alexander

    2017-01-01

    Accurately describing the anatomy of individual brains enables interlaboratory communication of functional and developmental studies and is crucial for possible surgical interventions. The human parietal lobe participates in multimodal sensory integration including language processing and also contains the primary somatosensory area. We describe detailed protocols to subdivide the parietal lobe, analyze morphological and volumetric characteristics, and create probabilistic atlases in MNI152 stereotaxic space. The parietal lobe was manually delineated on 3D T1 MR images of 30 healthy subjects and divided into four regions: supramarginal gyrus (SMG), angular gyrus (AG), superior parietal lobe (supPL) and postcentral gyrus (postCG). There was the expected correlation of male gender with larger brain and intracranial volume. We examined a wide range of anatomical features of the gyri and the sulci separating them. At least a rudimentary primary intermediate sulcus of Jensen (PISJ) separating SMG and AG was identified in nearly all (59/60) hemispheres. Presence of additional gyri in SMG and AG was related to sulcal features and volumetric characteristics. The parietal lobe was slightly (2%) larger on the left, driven by leftward asymmetries of the postCG and SMG. Intersubject variability was highest for SMG and AG, and lowest for postCG. Overall the morphological characteristics tended to be symmetrical, and volumes also tended to covary between hemispheres. This may reflect developmental as well as maturation factors. To assess the accuracy with which the labels can be used to segment newly acquired (unlabelled) T1-weighted brain images, we applied multi-atlas label propagation software (MAPER) in a leave-one-out experiment and compared the resulting automatic labels with the manually prepared ones. The results showed strong agreement (mean Jaccard index 0.69, corresponding to a mean Dice index of 0.82, average mean volume error of 0.6%). Stereotaxic probabilistic

  15. Functional integration of parietal lobe activity in early Alzheimer disease.

    Science.gov (United States)

    Jacobs, H I L; Van Boxtel, M P J; Heinecke, A; Gronenschild, E H B M; Backes, W H; Ramakers, I H G B; Jolles, J; Verhey, F R J

    2012-01-31

    Parietal lobe dysfunction is an important characteristic of early Alzheimer disease (AD). Functional studies have shown conflicting parietal activation patterns indicative of either compensatory or dysfunctional mechanisms. This study aimed at examining activation differences in early AD using a visuospatial task. We focused on functional characteristics of the parietal lobe and examined compensation or disconnection mechanisms by combining a fMRI task with effective connectivity measures from Granger causality mapping (GCM). Eighteen male patients with amnestic mild cognitive impairment (aMCI) and 18 male cognitively healthy older individuals were given a mental rotation task with different rotation angles. There were no behavioral group differences on the fMRI task. Separate measurements at each angle revealed widespread activation group differences. More temporal and parietal activation in the higher angle condition was observed in patients with aMCI. The parametric modulation, which identifies regions associated with increasing angle, confirmed these results. The GCM showed increased connectivity within the parietal lobe and between parietal and temporal regions in patients with aMCI. Decreased connectivity was found between the inferior parietal lobule and posterior cingulate gyrus. Connectivity patterns correlated with memory performance scores in patients with aMCI. Our results demonstrate increased effective temporoparietal connectivity in patients with aMCI, while maintaining intact behavioral performance. This might be a compensational mechanism to counteract a parietal-posterior cingulate gyrus disconnection. These findings highlight the importance of connectivity changes in the pathophysiology of AD. In addition, effective connectivity may be a promising method for evaluating interventions aimed at the promotion of compensatory mechanisms.

  16. A volumetric study of parietal lobe subregions in Turner syndrome

    OpenAIRE

    Brown, Wendy E.; Shelli R Kesler; Eliez, Stephan; Warsofsky, Ilana S.; Haberecht, Michael; Reiss, Allan L.

    2004-01-01

    Turner syndrome, a genetic disorder that results from the complete or partial absence of an X chromosome in females, has been associated with specific impairment in visuospatial cognition. Previous studies have demonstrated a relationship between parietal lobe abnormalities and visuospatial deficits in Turner syndrome. We used high-resolution magnetic resonance imaging to measure parietal lobe subdivisions in 14 participants with Turner syndrome (mean age 13 years 5 months, SD 5 years) and 14...

  17. Age-related temporal and parietal cortical thinning in autism spectrum disorders.

    Science.gov (United States)

    Wallace, Gregory L; Dankner, Nathan; Kenworthy, Lauren; Giedd, Jay N; Martin, Alex

    2010-12-01

    Studies of head size and brain volume in autism spectrum disorders have suggested that early cortical overgrowth may be followed by prematurely arrested growth. However, the few investigations quantifying cortical thickness have yielded inconsistent results, probably due to variable ages and/or small sample sizes. We assessed differences in cortical thickness between high-functioning adolescent and young adult males with autism spectrum disorders (n = 41) and matched typically developing males (n = 40). We hypothesized thinner cortex, particularly in frontal, parietal and temporal regions, for individuals with autism spectrum disorders in comparison with typically developing controls. Furthermore, we expected to find an age × diagnosis interaction: with increasing age, more pronounced cortical thinning would be observed in autism spectrum disorders than typically developing participants. T(1)-weighted magnetization prepared rapid gradient echo 3 T magnetic resonance imaging scans were acquired from high-functioning males with autism spectrum disorders and from typically developing males matched group-wise on age (range 12-24 years), intelligence quotient (≥ 85) and handedness. Both gyral-level and vertex-based analyses revealed significantly thinner cortex in the autism spectrum disorders group that was located predominantly in left temporal and parietal regions (i.e. the superior temporal sulcus, inferior temporal, postcentral/superior parietal and supramarginal gyri). These findings remained largely unchanged after controlling for intelligence quotient and after accounting for psychotropic medication usage and comorbid psychopathology. Furthermore, a significant age × diagnosis interaction was found in the left fusiform/inferior temporal cortex: participants with autism spectrum disorders had thinner cortex in this region with increasing age to a greater degree than did typically developing participants. Follow-up within group comparisons revealed significant

  18. Sex differences in parietal lobe structure and development.

    Science.gov (United States)

    Salinas, Joel; Mills, Elizabeth D; Conrad, Amy L; Koscik, Timothy; Andreasen, Nancy C; Nopoulos, Peg

    2012-02-01

    Structural magnetic resonance imaging studies provide evidence for sex differences in the human brain. Differences in surface area and the proportion of gray to white matter volume are observed, in particular in the parietal lobe. To our knowledge, no studies have examined sex differences in parietal lobe structure in younger populations or in the context of development. The present study evaluated sex differences in the structure of the parietal lobe in children aged 7 to 17 years. In addition, by adding a cohort of previously studied adults aged 18 to 50 years, sex differences in parietal lobe structure were examined across the age span of 7 to 50 years. Compared with the adult sample, the younger sample showed that the ratio of parietal lobe cortex to white matter was greater in female brains, but no sex differences in surface area. When examining the effects of age, surface area exhibited a significant sex-age interaction. In male brains, there was essentially no decrease in surfaces area over time, whereas in female brains, there was a significant decrease in surface area over time. These findings support the notion of structural sex differences in the parietal lobe, not only in the context of cross-sectional assessment but also in terms of differences in developmental trajectories. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.

  19. Surgical trauma and CO2-insufflation impact on adhesion formation in parietal and visceral peritoneal lesions.

    Science.gov (United States)

    Mynbaev, Ospan A; Eliseeva, Marina Yu; Kalzhanov, Zhomart R; Lyutova, Lv; Pismensky, Sergei V; Tinelli, Andrea; Malvasi, Antonio; Kosmas, Ioannis P

    2013-01-01

    CO2-insufflation and electrocoagulation were advanced as causative factors of postsurgical adhesions. We assumed that severe tissue reaction due to electrocoagulation might obscure CO2-insufflation impact on adhesion formation. Therefore, the purpose of this study was to evaluate the effects and interactions of surgical trauma and CO2-insufflation on adhesion formation. Prospective-randomized study with 60 rats, equally divided into 3 groups. In the control group, the sidewall adhesion model was induced by monopolar coagulation of the uterine horn and ipsilateral parietal peritoneum and by mechanical damaging - in the opposite side through open laparoscopy without CO2-insufflation. In two other groups, CO2 was insufflated for 60 min at 15 cm of water, either before or after the sidewall model-induction. Parameters of sidewall and lesion site adhesions of parietal peritoneum and uterine horns were evaluated by scoring system and analyzed by two-way ANOVA with Bonferroni posttests, one-way ANOVA Student-Newman-Keuls multiple comparisons test, as well as by two-tailed unpaired Mann-Whitney test. Monopolar coagulation significantly increased peritoneal lesion site adhesion scores, as compared with the scores for mechanical damaging (p=0.0001). Visceral peritoneal lesion sites were more predisposed to adhesion formation than parietal peritoneal lesion sites (p=0.0009), whereas CO2 did not affect parameters of either sidewall or peritoneal lesion site adhesions, regardless of the insufflation mode (p>0.05). The data suggest that both surgical trauma and peritoneal lesion sites had a substantial impact on adhesion formation, whereas CO2 did not interfere with adhesion parameters irrespective of its insufflation mode. These findings may improve our insights into adhesion formation pathophysiology and open new perspectives in developing future adhesion prevention strategies.

  20. Fronto-Parietal Contributions to Phonological Processes in Successful Artificial Grammar Learning

    Science.gov (United States)

    Goranskaya, Dariya; Kreitewolf, Jens; Mueller, Jutta L.; Friederici, Angela D.; Hartwigsen, Gesa

    2016-01-01

    Sensitivity to regularities plays a crucial role in the acquisition of various linguistic features from spoken language input. Artificial grammar 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. PMID:27877120

  1. Dissociable Memory- and Response-Related Activity in Parietal Cortex during Auditory Spatial Working Memory

    Directory of Open Access Journals (Sweden)

    Claude Alain

    2010-12-01

    Full Text Available Attending and responding to sound location generates increased activity in parietal cortex which may index auditory spatial working memory and/or goal-directed action. Here, we used an n-back task (Experiment 1 and an adaptation paradigm (Experiment 2 to distinguish memory-related activity from that associated with goal-directed action. In Experiment 1, participants indicated, in separate blocks of trials, whether the incoming stimulus was presented at the same location as in the previous trial (1-back or two trials ago (2-back. Prior to a block of trials, participants were told to use their left or right index finger. Accuracy and reaction times were worse for the 2-back than for the 1-back condition. The analysis of fMRI data revealed greater sustained task-related activity in the inferior parietal lobule (IPL and superior frontal sulcus during 2-back than 1-back after accounting for response-related activity elicited by the targets. Target detection and response execution were also associated with enhanced activity in the IPL bilaterally, though the activation was anterior to that associated with sustained task-related activity. In Experiment 2, we used an event-related design in which participants listened (no response required to trials that comprised four sounds presented either at the same location or at four different locations. We found larger IPL activation for changes in sound location than for sounds presented at the same location. The IPL activation overlapped with that observed during auditory spatial working memory task. Together, these results provide converging evidence supporting the role of parietal cortex in auditory spatial working memory which can be dissociated from response selection and execution.

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

    Directory of Open Access Journals (Sweden)

    Dariya Goranskaya

    2016-11-01

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

  3. Superior Hiking Trail

    Data.gov (United States)

    Minnesota Department of Natural Resources — Superior Hiking Trail main trail, spurs, and camp spurs for completed trail throughout Cook, Lake, St. Louis and Carlton counties. These data were collected with...

  4. Bathymetry of Lake Superior

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Superior has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  5. Superior Hiking Trail Facilities

    Data.gov (United States)

    Minnesota Department of Natural Resources — Superior Hiking Trail main trail, spurs, and camp spurs for completed trail throughout Cook, Lake, St. Louis and Carlton counties. These data were collected with...

  6. Cognitive and metacognitive activity in mathematical problem solving: prefrontal and parietal patterns.

    Science.gov (United States)

    Anderson, John R; Betts, Shawn; Ferris, Jennifer L; Fincham, Jon M

    2011-03-01

    Students were taught an algorithm for solving a new class of mathematical problems. Occasionally in the sequence of problems, they encountered exception problems that required that they extend the algorithm. Regular and exception problems were associated with different patterns of brain activation. Some regions showed a Cognitive pattern of being active only until the problem was solved and no difference between regular or exception problems. Other regions showed a Metacognitive pattern of greater activity for exception problems and activity that extended into the post-solution period, particularly when an error was made. The Cognitive regions included some of parietal and prefrontal regions associated with the triple-code theory of (Dehaene, S., Piazza, M., Pinel, P., & Cohen, L. (2003). Three parietal circuits for number processing. Cognitive Neuropsychology, 20, 487-506) and associated with algebra equation solving in the ACT-R theory (Anderson, J. R. (2005). Human symbol manipulation within an 911 integrated cognitive architecture. Cognitive science, 29, 313-342. Metacognitive regions included the superior prefrontal gyrus, the angular gyrus of the triple-code theory, and frontopolar regions.

  7. Expert cognitive control and individual differences associated with frontal and parietal white matter microstructure.

    Science.gov (United States)

    Roberts, R Edward; Anderson, Elaine J; Husain, Masud

    2010-12-15

    Although many functional imaging studies have reported frontal activity associated with "cognitive control" tasks, little is understood about factors underlying individual differences in performance. Here we compared the behavior and brain structure of healthy controls with fighter pilots, an expert group trained to make precision choices at speed in the presence of conflicting cues. Two different behavioral paradigms--Eriksen Flanker and change of plan tasks--were used to assess the influence of distractors and the ability to update ongoing action plans. Fighter pilots demonstrated superior cognitive control as indexed by accuracy and postconflict adaptation on the Flanker task, but also showed increased sensitivity to irrelevant, distracting choices. By contrast, when pilots were examined on their ability to inhibit a current action plan in favor of an alternative response, their performance was no better than the control group. Diffusion weighted imaging revealed differences in white matter radial diffusivity between pilots and controls not only in the right dorsomedial frontal region but also in the right parietal lobe. Moreover, analysis of individual differences in reaction time costs for conflict trials on the Flanker task demonstrated significant correlations with radial diffusivity at these locations, but in different directions. Postconflict adaptation effects, however, were confined to the dorsomedial frontal locus. The findings demonstrate that in humans expert cognitive control may surprisingly be mediated by enhanced response gain to both relevant and irrelevant stimuli, and is accompanied by structural alterations in the white matter of the frontal and parietal lobe.

  8. Reduced parietal connectivity with a premotor writing area in writer's cramp.

    Science.gov (United States)

    Delnooz, Cathérine C S; Helmich, Rick C; Toni, Ivan; van de Warrenburg, Bart P C

    2012-09-15

    Writer's cramp is a task-specific form of dystonia with symptoms characterized by abnormal movements and postures of the hand and arm evident only during writing. Its pathophysiology has been related to faulty sensorimotor integration, abnormal sensory processing, and impaired motor planning. Its symptoms might appear when the computational load of writing pushes a tonically altered circuit outside its operational range. Using resting-state fMRI, we tested whether writer's cramp patients have altered intrinsic functional connectivity in the premotor-parietal circuit. Sixteen patients with right-sided writer's cramp and 19 control subjects were studied. We show that writer's cramp patients have reduced connectivity between the superior parietal lobule and a dorsal precentral region that controls writing movements. This difference between patients and controls occurred in the absence of writing and only in the hemisphere contralateral to the affected hand. This finding adds a novel element to the pathophysiological substrate for writer's cramp, namely, task-independent alterations within a writing-related circuit.

  9. Double dissociation between motor and visual imagery in the posterior parietal cortex.

    Science.gov (United States)

    Pelgrims, Barbara; Andres, Michael; Olivier, Etienne

    2009-10-01

    Because motor imagery (MI) and visual imagery (VI) are influenced differently by factors such as biomechanical constraints or stimulus size, it is conceivable that they rely on separate processes, possibly involving distinct cortical networks, a view corroborated by neuroimaging and neuropsychological studies. In the posterior parietal cortex, it has been suggested that the superior parietal lobule (SPL) underlies VI, whereas MI relies on the supramarginalis gyrus (SMG). However, because several brain imaging studies have also shown an overlap of activations in SPL and SMG during VI or MI, the question arises as to which extent these 2 subregions really contribute to distinct imagery processes. To address this issue, we used repetitive transcranial magnetic stimulation to induce virtual lesions of either SMG or SPL in subjects performing a MI (hand drawing rotation) or a VI (letter rotation) task. Whatever hemisphere was stimulated, SMG lesions selectively altered MI, whereas SPL lesions only affected VI, demonstrating a double dissociation between MI and VI. Because these deficits were not influenced by the angular distance of the stimuli, we suggest that SMG and SPL are involved in the reenactment of the motor and visual representations, respectively, and not in mental rotation processes per se.

  10. Auditory cortical delta-entrainment interacts with oscillatory power in multiple fronto-parietal networks.

    Science.gov (United States)

    Keitel, Anne; Ince, Robin A A; Gross, Joachim; Kayser, Christoph

    2017-02-15

    The timing of slow auditory cortical activity aligns to the rhythmic fluctuations in speech. This entrainment is considered to be a marker of the prosodic and syllabic encoding of speech, and has been shown to correlate with intelligibility. Yet, whether and how auditory cortical entrainment is influenced by the activity in other speech-relevant areas remains unknown. Using source-localized MEG data, we quantified the dependency of auditory entrainment on the state of oscillatory activity in fronto-parietal regions. We found that delta band entrainment interacted with the oscillatory activity in three distinct networks. First, entrainment in the left anterior superior temporal gyrus (STG) was modulated by beta power in orbitofrontal areas, possibly reflecting predictive top-down modulations of auditory encoding. Second, entrainment in the left Heschl's Gyrus and anterior STG was dependent on alpha power in central areas, in line with the importance of motor structures for phonological analysis. And third, entrainment in the right posterior STG modulated theta power in parietal areas, consistent with the engagement of semantic memory. These results illustrate the topographical network interactions of auditory delta entrainment and reveal distinct cross-frequency mechanisms by which entrainment can interact with different cognitive processes underlying speech perception.

  11. Creating Colored Letters: Familial Markers of Grapheme-Color Synesthesia in Parietal Lobe Activation and Structure.

    Science.gov (United States)

    Colizoli, Olympia; Murre, Jaap M J; Scholte, H Steven; Rouw, Romke

    2017-07-01

    Perception is inherently subjective, and individual differences in phenomenology are well illustrated by the phenomenon of synesthesia (highly specific, consistent, and automatic cross-modal experiences, in which the external stimulus corresponding to the additional sensation is absent). It is unknown why some people develop synesthesia and others do not. In the current study, we tested whether neural markers related to having synesthesia in the family were evident in brain function and structure. Relatives of synesthetes (who did not have any type of synesthesia themselves) and matched controls read specially prepared books with colored letters for several weeks and were scanned before and after reading using magnetic resonance imaging. Effects of acquired letter-color associations were evident in brain activation. Training-related activation (while viewing black letters) in the right angular gyrus of the parietal lobe was directly related to the strength of the learned letter-color associations (behavioral Stroop effect). Within this obtained angular gyrus ROI, the familial trait of synesthesia related to brain activation differences while participants viewed both black and colored letters. Finally, we compared brain structure using voxel-based morphometry and diffusion tensor imaging to test for group differences and training effects. One cluster in the left superior parietal lobe had significantly more coherent white matter in the relatives compared with controls. No evidence for experience-dependent plasticity was obtained. For the first time, we present evidence suggesting that the (nonsynesthete) relatives of grapheme-color synesthetes show atypical grapheme processing as well as increased brain connectivity.

  12. A parcellation scheme for human left lateral parietal cortex.

    Science.gov (United States)

    Nelson, Steven M; Cohen, Alexander L; Power, Jonathan D; Wig, Gagan S; Miezin, Francis M; Wheeler, Mark E; Velanova, Katerina; Donaldson, David I; Phillips, Jeffrey S; Schlaggar, Bradley L; Petersen, Steven E

    2010-07-15

    The parietal lobe has long been viewed as a collection of architectonic and functional subdivisions. Though much parietal research has focused on mechanisms of visuospatial attention and control-related processes, more recent functional neuroimaging studies of memory retrieval have reported greater activity in left lateral parietal cortex (LLPC) when items are correctly identified as previously studied ("old") versus unstudied ("new"). These studies have suggested functional divisions within LLPC that may provide distinct contributions toward recognition memory judgments. Here, we define regions within LLPC by developing a parcellation scheme that integrates data from resting-state functional connectivity MRI and functional MRI. This combined approach results in a 6-fold parcellation of LLPC based on the presence (or absence) of memory-retrieval-related activity, dissociations in the profile of task-evoked time courses, and membership in large-scale brain networks. This parcellation should serve as a roadmap for future investigations aimed at understanding LLPC function.

  13. The Role of Right Inferior Parietal Cortex in Auditory Spatial Attention: A Repetitive Transcranial Magnetic Stimulation Study.

    Directory of Open Access Journals (Sweden)

    Debra S Karhson

    Full Text Available Behavioral studies support the concept of an auditory spatial attention gradient by demonstrating that attentional benefits progressively diminish as distance increases from an attended location. Damage to the right inferior parietal cortex can induce a rightward attention bias, which implicates this region in the construction of attention gradients. This study used event-related potentials (ERPs to define attention-related gradients before and after repetitive transcranial magnetic stimulation (rTMS to the right inferior parietal cortex. Subjects (n = 16 listened to noise bursts at five azimuth locations (left to right: -90°, -45°, 0° midline, +45°, +90° and responded to stimuli at one target location (-90°, +90°, separate blocks. ERPs as a function of non-target location were examined before (baseline and after 0.9 Hz rTMS. Results showed that ERP attention gradients were observed in three time windows (frontal 230-340, parietal 400-460, frontal 550-750 ms. Significant transient rTMS effects were seen in the first and third windows. The first window had a voltage decrease at the farthest location when attending to either the left or right side. The third window had on overall increase in positivity, but only when attending to the left side. These findings suggest that rTMS induced a small contraction in spatial attention gradients within the first time window. The asymmetric effect of attended location on gradients in the third time window may relate to neglect of the left hemispace after right parietal injury. Together, these results highlight the role of the right inferior parietal cortex in modulating frontal lobe attention network activity.

  14. PERSISTENT LEFT SUPERIOR VENACAVA

    Directory of Open Access Journals (Sweden)

    Devinder Singh

    2014-05-01

    Full Text Available A Persistent Left Superior Venacava (PLSVC is the most common variation of the thoracic venous system and rare congenital vascular anomaly and is prevalent in 0.3% of the population. It may be associated with other cardiovascular abnormalities including atrial septal defect, bicuspid aortic valve, coarctation of aorta, coronary sinus ostial atresia, and cor triatriatum. Incidental rotation of a dilated coronary sinus on echocardiography should raise the suspicion of PLSVC. The diagnosis should be confirmed by saline contrast echocardiography. Condition is usually asymptomatic. Here we present a rare case of persistent left superior vena cava presented in OPD with dyspnoea & palpitations.

  15. Superior memorizers employ different neural networks for encoding and recall.

    Science.gov (United States)

    Mallow, Johannes; Bernarding, Johannes; Luchtmann, Michael; Bethmann, Anja; Brechmann, André

    2015-01-01

    Superior memorizers often employ the method of loci (MoL) to memorize large amounts of information. The MoL, known since ancient times, relies on a complex process where information to be memorized is bound to landmarks along mental routes in a previously memorized environment. However, functional magnetic resonance imaging data on groups of trained superior memorizer are rare. Based on the memorizing strategy reported by superior memorizers, we developed a scheme of the processes successively employed during memorizing and recalling digits and relate these to brain activation that is specific for the encoding and recall period. In the examined superior memorizers several regions, suggested to be involved in mental navigation and digit-to-word processing, were specifically activated during encoding: bilateral early visual cortex, retrosplenial cortex, left parahippocampus, left visual cortex, and left superior parietal cortex. Although the scheme suggests that some steps during encoding and recall seem to be analog, none of the encoding areas were specifically activated during the recall. Instead, we found strong activation in left anterior superior temporal gyrus, which we relate to recalling the sequential order of the digits, and right motor cortex that may be related to reciting the digits.

  16. Superior Memorizers Employ Different Neural Networks for Encoding and Recall

    Directory of Open Access Journals (Sweden)

    Johannes eMallow

    2015-09-01

    Full Text Available Superior memorizers often employ the method of loci (MoL to memorize large amounts of information. The method of loci, known since ancient times, relies on a complex process where information to be memorized is bound to landmarks along mental routes in a previously memorized environment. However, fMRI data on groups of trained superior memorizer are rare. Based on the memorizing strategy reported by superior memorizers we developed a scheme of the processes successively employed during memorizing and recalling digits and relate these to brain activation that is specific for the encoding and recall period. In the examined superior memorizers several regions, suggested to be involved in mental navigation and digit-to-word processing, were specifically activated during encoding: bilateral early visual cortex, retrosplenial cortex, left parahippocampus, left visual cortex, and left superior parietal cortex. Although the scheme suggests that some steps during encoding and recall seem to be analog, none of the encoding areas were specifically activated during the recall. Instead, we found strong activation in left anterior superior temporal gyrus, which we relate to recalling the sequential order of the digits, and right motor cortex that may be related to reciting the digits.

  17. Superior digit memory of abacus experts: an event-related functional MRI study.

    Science.gov (United States)

    Tanaka, Satoshi; Michimata, Chikashi; Kaminaga, Tatsuro; Honda, Manabu; Sadato, Norihiro

    2002-12-01

    Abacus experts exhibit superior short-term memory for digits, but the underlying neurophysiological mechanism remains unknown. Using event-related fMRI, we examined the brain activity of abacus experts and non-experts during the memory retention period of a delayed match-to-sample task using digits as stimuli. In controls, activity was greater in cortical areas related to verbal working memory, including Broca's area. In contrast, in experts, activity was greater in cortical areas related to visuo-spatial working memory, including the bilateral superior frontal sulcus and superior parietal lobule. This provides neurophysiological evidence that abacus experts utilize a visuo-spatial representation for digit memory.

  18. Replenishment of the podocyte compartment by parietal epithelial cells.

    Science.gov (United States)

    Kopp, Jeffrey B

    2015-11-01

    While progressive podocytopenia is a characteristic feature of chronic glomerular disease, the visceral epithelial niche can be replenished from the parietal epithelium. Two new reports demonstrate this process in genetically engineered mice, using fate mapping, and in human renal biopsies manifesting segmental glomerulosclerosis in diverse settings, using cellular and extracellular matrix markers.

  19. Parietal network underlying movement control: disturbances during subcortical electrostimulation.

    Science.gov (United States)

    Almairac, Fabien; Herbet, Guillaume; Moritz-Gasser, Sylvie; Duffau, Hugues

    2014-07-01

    Our understanding of brain movement control has changed over the last two decades. Recent findings in the monkey and in humans have led to a parallel and interconnected network. Nevertheless, little is known about these networks. Here, we present two cases of patients with a parietal low-grade glioma. They underwent surgery under local anesthesia with cortical and subcortical mapping. For patient 1, subcortical electrostimulation immediately posterior to thalamocortical fibers induced movement disorders, with an inhibition of leg and arm movements medially and, more laterally, an acceleration of arm movement. For patient 2, electrostimulation of white matter immediately posterior to thalamocortical fibers induced an inhibition of both arm movement. It means that the detected fibers in the parietal lobe may be involved in the motor control modulation. They are distributed veil-like immediately posterior to thalamocortical pathways and could correspond to a fronto-parietal movement control subnetwork. These two cases highlight the major role of the subcortical connectivity in movement regulation, involving parietal lobe, thus the necessity to be identified and preserved during brain surgery.

  20. Left inferior parietal lobe engagement in social cognition and language.

    Science.gov (United States)

    Bzdok, Danilo; Hartwigsen, Gesa; Reid, Andrew; Laird, Angela R; Fox, Peter T; Eickhoff, Simon B

    2016-09-01

    Social cognition and language are two core features of the human species. Despite distributed recruitment of brain regions in each mental capacity, the left parietal lobe (LPL) represents a zone of topographical convergence. The present study quantitatively summarizes hundreds of neuroimaging studies on social cognition and language. Using connectivity-based parcellation on a meta-analytically defined volume of interest (VOI), regional coactivation patterns within this VOI allowed identifying distinct subregions. Across parcellation solutions, two clusters emerged consistently in rostro-ventral and caudo-ventral aspects of the parietal VOI. Both clusters were functionally significantly associated with social-cognitive and language processing. In particular, the rostro-ventral cluster was associated with lower-level processing facets, while the caudo-ventral cluster was associated with higher-level processing facets in both mental capacities. Contrarily, in the (less stable) dorsal parietal VOI, all clusters reflected computation of general-purpose processes, such as working memory and matching tasks, that are frequently co-recruited by social or language processes. Our results hence favour a rostro-caudal distinction of lower- versus higher-level processes underlying social cognition and language in the left inferior parietal lobe. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Left inferior parietal lobe engagement in social cognition and language

    NARCIS (Netherlands)

    Bzdok, D.; Hartwigsen, G.; Reid, A.T.; Laird, A.R.; Fox, P.T.; Eickhoff, S.B.

    2016-01-01

    Social cognition and language are two core features of the human species. Despite distributed recruitment of brain regions in each mental capacity, the left parietal lobe (LPL) represents a zone of topographical convergence. This study quantitatively summarizes previous neuroimaging studies on

  2. Parietal cortex mediates perceptual Gestalt grouping independent of stimulus size.

    Science.gov (United States)

    Grassi, Pablo R; Zaretskaya, Natalia; Bartels, Andreas

    2016-06-01

    The integration of local moving elements into a unified gestalt percept has previously been linked to the posterior parietal cortex. There are two possible interpretations for the lack of involvement of other occipital regions. The first is that parietal cortex is indeed uniquely functionally specialized to perform grouping. Another possibility is that other visual regions can perform grouping as well, but that the large spatial separation of the local elements used previously exceeded their neurons' receptive field (RF) sizes, preventing their involvement. In this study we distinguished between these two alternatives. We measured whole-brain activity using fMRI in response to a bistable motion illusion that induced mutually exclusive percepts of either an illusory global Gestalt or of local elements. The stimulus was presented in two sizes, a large version known to activate IPS only, and a version sufficiently small to fit into the RFs of mid-level dorsal regions such as V5/MT. We found that none of the separately localized motion regions apart from parietal cortex showed a preference for global Gestalt perception, even for the smaller version of the stimulus. This outcome suggests that grouping-by-motion is mediated by a specialized size-invariant mechanism with parietal cortex as its anatomical substrate. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Multiple parietal-frontal pathways mediate grasping in macaque monkeys

    Science.gov (United States)

    Gharbawie, Omar A.; Stepniewska, Iwona; Qi, Huixin; Kaas, Jon H.

    2011-01-01

    The nodes of a parietal-frontal pathway that mediates grasping in primates are in anterior intraparietal area (AIP) and ventral premotor cortex (PMv). Nevertheless, multiple somatosensory and motor representations of the hand, respectively in parietal and frontal cortex, suggest that additional pathways remain unrealized. We explored this possibility in macaque monkeys by injecting retrograde tracers into grasp zones identified in M1, PMv, and area 2 with long train electrical stimulation. The M1 grasp zone was densely connected with other frontal cortex motor regions. The remainder of the connections originated from somatosensory areas 3a and S2/PV, and from the medial bank and fundus of the intraparietal sulcus (IPS). The PMv grasp zone was also densely connected with frontal cortex motor regions, albeit to a lesser extent than the M1 grasp zone. The remainder of the connections originated from areas S2/PV and aspects of the inferior parietal lobe such as PF, PFG, AIP, and the tip of the IPS. The area 2 grasp zone was densely connected with the hand representations of somatosensory areas 3b, 1, and S2/PV. The remainder of the connections was with areas 3a and 5 and the medial bank and fundus of the IPS. Connections with frontal cortex were relatively weak and concentrated in caudal M1. Thus, the three grasp zones may be nodes of parallel parietal-frontal pathways. Differential points of origin and termination of each pathway suggest varying functional specializations. Direct and indirect connections between those parietal-frontal pathways likely coordinate their respective functions into an accurate grasp. PMID:21832196

  4. Lesion correlates of impairments in actual tool use following unilateral brain damage.

    Science.gov (United States)

    Salazar-López, E; Schwaiger, B J; Hermsdörfer, J

    2016-04-01

    To understand how the brain controls actions involving tools, tests have been developed employing different paradigms such as pantomime, imitation and real tool use. The relevant areas have been localized in the premotor cortex, the middle temporal gyrus and the superior and inferior parietal lobe. This study employs Voxel Lesion Symptom Mapping to relate the functional impairment in actual tool use with extent and localization of the structural damage in the left (LBD, N=31) and right (RBD, N=19) hemisphere in chronic stroke patients. A series of 12 tools was presented to participants in a carousel. In addition, a non-tool condition tested the prescribed manipulation of a bar. The execution was scored according to an apraxic error scale based on the dimensions grasp, movement, direction and space. Results in the LBD group show that the ventro-dorsal stream constitutes the core of the defective network responsible for impaired tool use; it is composed of the inferior parietal lobe, the supramarginal and angular gyrus and the dorsal premotor cortex. In addition, involvement of regions in the temporal lobe, the rolandic operculum, the ventral premotor cortex and the middle occipital gyrus provide evidence of the role of the ventral stream in this task. Brain areas related to the use of the bar largely overlapped with this network. For patients with RBD data were less conclusive; however, a trend for the involvement of the temporal lobe in apraxic errors was manifested. Skilled bar manipulation depended on the same temporal area in these patients. Therefore, actual tool use depends on a well described left fronto-parietal-temporal network. RBD affects actual tool use, however the underlying neural processes may be more widely distributed and more heterogeneous. Goal directed manipulation of non-tool objects seems to involve very similar brain areas as tool use, suggesting that both types of manipulation share identical processes and neural representations. Copyright

  5. Air Superiority Fighter Characteristics.

    Science.gov (United States)

    1998-06-05

    many a dispute could have been deflated into a single paragraph if the disputants had just dared to define their terms.7 Aristotle ...meaningful. This section will expand on some key ideology concepts. The phrase "air superiority fighter" may bring to mind visions of fighter... biographies are useful in garnering airpower advocate theories as well as identifying key characteristics. Air campaign results, starting with World

  6. Individual differences in left parietal white matter predict math scores on the Preliminary Scholastic Aptitude Test.

    Science.gov (United States)

    Matejko, Anna A; Price, Gavin R; Mazzocco, Michèle M M; Ansari, Daniel

    2013-02-01

    Mathematical skills are of critical importance, both academically and in everyday life. Neuroimaging research has primarily focused on the relationship between mathematical skills and functional brain activity. Comparatively few studies have examined which white matter regions support mathematical abilities. The current study uses diffusion tensor imaging (DTI) to test whether individual differences in white matter predict performance on the math subtest of the Preliminary Scholastic Aptitude Test (PSAT). Grades 10 and 11 PSAT scores were obtained from 30 young adults (ages 17-18) with wide-ranging math achievement levels. Tract based spatial statistics was used to examine the correlation between PSAT math scores, fractional anisotropy (FA), radial diffusivity (RD) and axial diffusivity (AD). FA in left parietal white matter was positively correlated with math PSAT scores (specifically in the left superior longitudinal fasciculus, left superior corona radiata, and left corticospinal tract) after controlling for chronological age and same grade PSAT critical reading scores. Furthermore, RD, but not AD, was correlated with PSAT math scores in these white matter microstructures. The negative correlation with RD further suggests that participants with higher PSAT math scores have greater white matter integrity in this region. Individual differences in FA and RD may reflect variability in experience dependent plasticity over the course of learning and development. These results are the first to demonstrate that individual differences in white matter are associated with mathematical abilities on a nationally administered scholastic aptitude measure.

  7. Semantic retrieval during overt picture description: Left anterior temporal or the parietal lobe?

    Science.gov (United States)

    Geranmayeh, Fatemeh; Leech, Robert; Wise, Richard J S

    2015-09-01

    Retrieval of semantic representations is a central process during overt speech production. There is an increasing consensus that an amodal semantic 'hub' must exist that draws together modality-specific representations of concepts. Based on the distribution of atrophy and the behavioral deficit of patients with the semantic variant of fronto-temporal lobar degeneration, it has been proposed that this hub is localized within both anterior temporal lobes (ATL), and is functionally connected with verbal 'output' systems via the left ATL. An alternative view, dating from Geschwind's proposal in 1965, is that the angular gyrus (AG) is central to object-based semantic representations. In this fMRI study we examined the connectivity of the left ATL and parietal lobe (PL) with whole brain networks known to be activated during overt picture description. We decomposed each of these two brain volumes into 15 regions of interest (ROIs), using independent component analysis. A dual regression analysis was used to establish the connectivity of each ROI with whole brain-networks. An ROI within the left anterior superior temporal sulcus (antSTS) was functionally connected to other parts of the left ATL, including anterior ventromedial left temporal cortex (partially attenuated by signal loss due to susceptibility artifact), a large left dorsolateral prefrontal region (including 'classic' Broca's area), extensive bilateral sensory-motor cortices, and the length of both superior temporal gyri. The time-course of this functionally connected network was associated with picture description but not with non-semantic baseline tasks. This system has the distribution expected for the production of overt speech with appropriate semantic content, and the auditory monitoring of the overt speech output. In contrast, the only left PL ROI that showed connectivity with brain systems most strongly activated by the picture-description task, was in the superior parietal lobe (supPL). This region

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

    Science.gov (United States)

    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…

  9. 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…

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

    Science.gov (United States)

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

    2011-01-01

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

  11. Recognition and imitation of pantomimed motor acts after unilateral parietal and premotor lesions: a perspective on apraxia.

    Science.gov (United States)

    Halsband, U; Schmitt, J; Weyers, M; Binkofski, F; Grützner, G; Freund, H J

    2001-01-01

    We compared gesture comprehension and imitation in patients with lesions in the left parietal lobe (LPAR, n=5) and premotor cortex/supplementary motor area (LPMA, n=8) in patients with damage to the right parietal lobe (RPAR, n=6) and right premotor/supplementary motor area (RPMA, n=6) and in 16 non-brain damaged control subjects. Three patients with left parietal lobe damage had aphasia. Subjects were shown 136 meaningful pantomimed motor acts on a videoscreen and were asked to identify the movements and to imitate the motor acts from memory with their ipsilesional and contralesional hand or with both hands simultaneously. Motor tasks included gestures without object use (e.g. to salute, to wave) pantomimed imitation of gestures on one's own body (e.g. to comb one's hair) and pantomimed imitation of motor acts which imply tool use to an object in extrapersonal space (e.g. to hammer a nail). Videotaped test performance was analysed by two independent raters; errors were classified as spatial errors, body part as object, parapraxic performance and non-identifiable movements. In addition, action discrimination was tested by evaluating whether a complex motor sequence was correctly performed. Results indicate that LPAR patients were most severely disturbed when imitation performance was assessed. Interestingly, LPAR patients were worse when imitating gestures on their own bodies than imitating movements with reference to an external object use with most pronounced deficits in the spatial domain. In contrast to imitation, comprehension was not or only slightly disturbed and no clear correlation was found between the severity of imitation deficits and gesture comprehension. Moreover, although the three patients with aphasia imitated the movements more poorly than non-aphasic LPAR patients, the severity of comprehension errors did not differ. Whereas unimanual imitating performance and gesture comprehension of PMA patients did not differ significantly from control

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

    Directory of Open Access Journals (Sweden)

    V Benagiano

    2009-06-01

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

  13. A case of lipoma of parietal peritoneum causing abdominal pain.

    Science.gov (United States)

    Bang, Chang Seok; Kim, Yeon Soo; Baik, Gwang Ho; Han, Sang Hak

    2014-06-01

    Lipomas are common benign tumors of mature adipose tissue, enclosed by thin fibrous capsules. They can occur on any part of the body; however, peritoneal lipoma is extremely rare. We encountered a case of a 75-year-old man presenting with intermittent abdominal pain, who had undergone right hemicolectomy due to colon cancer. Abdominal computerized tomography showed a well-defined heterogenous fatty mass measuring 4.5 × 3.5 cm in size, suggesting fat necrosis located in the abdominal wall. Laparotomy showed a very large soft mass of peritoneum. Pathologically, the tumor was diagnosed as lipoma containing fat necrosis located in parietal peritoneum not fixed to any organs, but with small bowel adhesion. Due to its rare etiologic origin and obscure cause of development, we report on a case of lipoma of parietal peritoneum causing abdominal pain.

  14. Gelastic seizures and fever originating from a parietal cortical dysplasia

    Directory of Open Access Journals (Sweden)

    Sana Chaouki

    2013-01-01

    Full Text Available Gelastic seizures (GS is an uncommon seizure type characterized by sudden inappropriate attacks of uncontrolled and unmotivated laugh and its diagnostic criteria were elaborated by Gascon. These criteria included stereotypical recurrence of laugh, which is unjustified by the context, associated signs compatible with seizure, and ictal or interictal abnormalities. GS can be cryptogenic or symptomatic of a variety of cerebral lesions, the most common being hypothalamic hamartoma. However, GS associated with other types of cerebral lesions are exceedingly rare. The physiopathologic mechanisms of this type of seizure are still undefined. Two reports have described a non-lesional GS arising from a parietal focus. In this paper, we report the first case of lesional GS associated to the parietal area of the brain in a child and this case has associated fever that is likely an ictal symptom.

  15. El arte parietal, espejo de las sociedades paleolíticas

    Directory of Open Access Journals (Sweden)

    Georges SAUVET

    2009-12-01

    Full Text Available RESUMEN: El presente trabajo aboga por un estudio del arte parietal como instrumento del conocimiento de la geografía humana de las sociedades de cazadores y de la evolución de sus redes de alianza, durante el Paleolítico superior. Tomando como ejemplo el componente figurativo de este arte y un amplio corpus de 3981 figuras procedentes de 154 yacimientos franceses y españoles, se demuestra que las asociaciones entre especies animales diferentes obedecen a reglas simples y coherentes, que se dejan fácilmente exprimir por un modelo formal. El análisis de doce sub-conjuntos sincrónicos y diacrónicos evidencia la movilidad de las connexiones interregionales (por ejemplo el desarrollo del Solutrense cantábrico en relación con los centros peninsulares y con escaso contacto con el sudoeste francés, al contrario de la situación que prevalece durante el Magdaleniense medio-superior. Sin embargo conforta la idea que las variaciones regionales operan dentro de un sistema de pensamiento religioso relativamente estable. Una segunda fase del trabajo se propone describir la estructuración del arte parietal a un nivel mucho más fino, teniendo en cuenta la diversidad formal de cada figura y sus relaciones topológicas con las demás. Una larga base de datos está en curso de elaboración para su tratamiento con las técnicas de "extracción de conocimiento" (Knowledge Discovery in Databases. Unos resultados preliminares dejan esperar que una base de datos de este tipo servirá el objetivo y proporcionará une visión más precisa y segura de la historia de los pueblos paleolíticos, dado que la fuente del estilo propio de cada grupo debe buscarse en la construcción gráfica de paneles complejos.ABSTRACT: This paper pleads in favour of the study of parietal art as a means to investigate the human geography of palaeolithic hunter-gatherers in Europe and the evolution of their alliance networks. Taking the example of the figurative component of Rock

  16. Contabilidad Financiera Superior

    OpenAIRE

    Ipiñazar Petralanda, Izaskun

    2013-01-01

    Duración (en horas): De 31 a 40 horas. Destinatario: Estudiante y Docente A través de este material se presentan las pautas necesarias para implementar un aprendizaje basado en problemas en la asignatura de Contabilidad Financiera Superior dentro de los temas “Constitución de S.A. y S.R.L.” (Tema 2), “Ampliaciones de Capital” (Tema 3) y “Reducciones de Capital” (Tema 4). En primer lugar se presentan las guías generales de la asignatura, y a continuación, las diferentes activida...

  17. Contabilidad Financiera Superior

    OpenAIRE

    Ipiñazar Petralanda, Izaskun

    2013-01-01

    Duración (en horas): De 31 a 40 horas. Destinatario: Estudiante y Docente A través de este material se presentan las pautas necesarias para implementar un aprendizaje basado en problemas en la asignatura de Contabilidad Financiera Superior dentro de los temas “Constitución de S.A. y S.R.L.” (Tema 2), “Ampliaciones de Capital” (Tema 3) y “Reducciones de Capital” (Tema 4). En primer lugar se presentan las guías generales de la asignatura, y a continuación, las diferentes activida...

  18. Gestalt perception is associated with reduced parietal beta oscillations.

    Science.gov (United States)

    Zaretskaya, Natalia; Bartels, Andreas

    2015-05-15

    The ability to perceive composite objects as a whole is fundamental for visual perception in a complex and cluttered natural environment. This ability may be mediated by increased communication between neural representations of distinct object elements, and has been linked to increased synchronization of oscillatory brain activity in the gamma band. Previous studies of perceptual grouping either guided attention between local and global aspects of a given stimulus or manipulated its physical properties to achieve grouped and ungrouped perceptual conditions. In contrast to those studies, we fully matched the physical properties underlying global and local percepts using a bistable stimulus that causes the viewer to perceive either local motion of multiple elements or global motion of two illusory shapes without any external change. To test the synchronization hypothesis we recorded brain activity with EEG, while human participants viewed the stimulus and reported changes in their perception. In contrast to previous findings we show that power of the beta-band was lower during perception of global Gestalt than during that of local elements. Source localization places these differences in the posterior parietal cortex, overlapping with a site previously associated with both attention and Gestalt perception. These findings reveal a role of parietal beta-band activity in internally, rather than externally or attention-driven processes of Gestalt perception. They also add to the growing evidence for shared neural substrates of attention and Gestalt perception, both being linked to parietal cortex. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Association of dorsal inferior frontooccipital fasciculus fibers in the deep parietal lobe with both reading and writing processes: a brain mapping study.

    Science.gov (United States)

    Motomura, Kazuya; Fujii, Masazumi; Maesawa, Satoshi; Kuramitsu, Shunichiro; Natsume, Atsushi; Wakabayashi, Toshihiko

    2014-07-01

    Alexia and agraphia are disorders common to the left inferior parietal lobule, including the angular and supramarginal gyri. However, it is still unclear how these cortical regions interact with other cortical sites and what the most important white matter tracts are in relation to reading and writing processes. Here, the authors present the case of a patient who underwent an awake craniotomy for a left inferior parietal lobule glioma using direct cortical and subcortical electrostimulation. The use of subcortical stimulation allowed identification of the specific white matter tracts associated with reading and writing. These tracts were found as portions of the dorsal inferior frontooccipital fasciculus (IFOF) fibers in the deep parietal lobe that are responsible for connecting the frontal lobe to the superior parietal lobule. These findings are consistent with previous diffusion tensor imaging tractography and functional MRI studies, which suggest that the IFOF may play a role in the reading and writing processes. This is the first report of transient alexia and agraphia elicited through intraoperative direct subcortical electrostimulation, and the findings support the crucial role of the IFOF in reading and writing.

  1. Statistics of superior records

    Science.gov (United States)

    Ben-Naim, E.; Krapivsky, P. L.

    2013-08-01

    We study statistics of records in a sequence of random variables. These identical and independently distributed variables are drawn from the parent distribution ρ. The running record equals the maximum of all elements in the sequence up to a given point. We define a superior sequence as one where all running records are above the average record expected for the parent distribution ρ. We find that the fraction of superior sequences SN decays algebraically with sequence length N, SN˜N-β in the limit N→∞. Interestingly, the decay exponent β is nontrivial, being the root of an integral equation. For example, when ρ is a uniform distribution with compact support, we find β=0.450265. In general, the tail of the parent distribution governs the exponent β. We also consider the dual problem of inferior sequences, where all records are below average, and find that the fraction of inferior sequences IN decays algebraically, albeit with a different decay exponent, IN˜N-α. We use the above statistical measures to analyze earthquake data.

  2. Frenillo labial superior doble

    Directory of Open Access Journals (Sweden)

    Carlos Albornoz López del Castillo

    Full Text Available El frenillo labial superior doble no sindrómico es una anomalía del desarrollo que no hemos encontrado reportada en la revisión bibliográfica realizada. Se presenta una niña de 11 años de edad que fue remitida al servicio de Cirugía Maxilofacial del Hospital "Eduardo Agramonte Piña", de Camagüey, por presentar un frenillo labial superior doble de baja inserción. Se describen los síntomas clínicos asociados a esta anomalía y el tratamiento quirúrgico utilizado para su solución: una frenectomía y plastia sobre la banda muscular frénica anormal que provocaba exceso de tejido en la mucosa labial. Consideramos muy interesante la descripción de este caso, por no haber encontrado reporte similar en la literatura revisada.

  3. Scene-Selectivity and Retinotopy in Medial Parietal Cortex

    Science.gov (United States)

    Silson, Edward H.; Steel, Adam D.; Baker, Chris I.

    2016-01-01

    Functional imaging studies in human reliably identify a trio of scene-selective regions, one on each of the lateral [occipital place area (OPA)], ventral [parahippocampal place area (PPA)], and medial [retrosplenial complex (RSC)] cortical surfaces. Recently, we demonstrated differential retinotopic biases for the contralateral lower and upper visual fields within OPA and PPA, respectively. Here, using functional magnetic resonance imaging, we combine detailed mapping of both population receptive fields (pRF) and category-selectivity, with independently acquired resting-state functional connectivity analyses, to examine scene and retinotopic processing within medial parietal cortex. We identified a medial scene-selective region, which was contained largely within the posterior and ventral bank of the parieto-occipital sulcus (POS). While this region is typically referred to as RSC, the spatial extent of our scene-selective region typically did not extend into retrosplenial cortex, and thus we adopt the term medial place area (MPA) to refer to this visually defined scene-selective region. Intriguingly MPA co-localized with a region identified solely on the basis of retinotopic sensitivity using pRF analyses. We found that MPA demonstrates a significant contralateral visual field bias, coupled with large pRF sizes. Unlike OPA and PPA, MPA did not show a consistent bias to a single visual quadrant. MPA also co-localized with a region identified by strong differential functional connectivity with PPA and the human face-selective fusiform face area (FFA), commensurate with its functional selectivity. Functional connectivity with OPA was much weaker than with PPA, and similar to that with face-selective occipital face area (OFA), suggesting a closer link with ventral than lateral cortex. Consistent with prior research, we also observed differential functional connectivity in medial parietal cortex for anterior over posterior PPA, as well as a region on the lateral

  4. Damage to Temporo-Parietal Cortex Decreases Incidental Activation of Thematic Relations during Spoken Word Comprehension

    Science.gov (United States)

    Mirman, Daniel; Graziano, Kristen M.

    2012-01-01

    Both taxonomic and thematic semantic relations have been studied extensively in behavioral studies and there is an emerging consensus that the anterior temporal lobe plays a particularly important role in the representation and processing of taxonomic relations, but the neural basis of thematic semantics is less clear. We used eye tracking to…

  5. Fluid intelligence loss linked to restricted regions of damage within frontal and parietal cortex

    OpenAIRE

    Woolgar, Alexandra; Parr, Alice; Cusack, Rhodri; Thompson, Russell; Nimmo-Smith, Ian; Torralva, Teresa; Roca, Maria; Antoun, Nagui; Manes, Facundo; Duncan, John

    2010-01-01

    Tests of fluid intelligence predict success in a wide range of cognitive activities. Much uncertainty has surrounded brain lesions producing deficits in these tests, with standard group comparisons delivering no clear result. Based on findings from functional imaging, we propose that the uncertainty of lesion data may arise from the specificity and complexity of the relevant neural circuit. Fluid intelligence tests give a characteristic pattern of activity in posterolateral frontal, dorsomedi...

  6. Syndecan-1 in the mouse parietal peritoneum microcirculation in inflammation.

    Directory of Open Access Journals (Sweden)

    Paulina M Kowalewska

    Full Text Available BACKGROUND: The heparan sulfate proteoglycan syndecan-1 (CD138 was shown to regulate inflammatory responses by binding chemokines and cytokines and interacting with adhesion molecules, thereby modulating leukocyte trafficking to tissues. The objectives of this study were to examine the expression of syndecan-1 and its role in leukocyte recruitment and chemokine presentation in the microcirculation underlying the parietal peritoneum. METHODS: Wild-type BALB/c and syndecan-1 null mice were stimulated with an intraperitoneal injection of Staphylococcus aureus LTA, Escherichia coli LPS or TNFα and the microcirculation of the parietal peritoneum was examined by intravital microscopy after 4 hours. Fluorescence confocal microscopy was used to examine syndecan-1 expression in the peritoneal microcirculation using fluorescent antibodies. Blocking antibodies to adhesion molecules were used to examine the role of these molecules in leukocyte-endothelial cell interactions in response to LTA. To determine whether syndecan-1 co-localizes with chemokines in vivo, fluorescent antibodies to syndecan-1 were co-injected intravenously with anti-MIP-2 (CXCL2, anti-KC (CXCL1 or anti-MCP-1 (CCL2. RESULTS AND CONCLUSION: Syndecan-1 was localized to the subendothelial region of peritoneal venules and the mesothelial layer. Leukocyte rolling was significantly decreased with LPS treatment while LTA and TNFα significantly increased leukocyte adhesion compared with saline control. Leukocyte-endothelial cell interactions were not different in syndecan-1 null mice. Antibody blockade of β2 integrin (CD18, ICAM-1 (CD54 and VCAM-1 (CD106 did not decrease leukocyte adhesion in response to LTA challenge while blockade of P-selectin (CD62P abrogated leukocyte rolling. Lastly, MIP-2 expression in the peritoneal venules was not dependent on syndecan-1 in vivo. Our data suggest that syndecan-1 is expressed in the parietal peritoneum microvasculature but does not regulate leukocyte

  7. Refractory Lesional Parietal Lobe Epilepsy: Clinical, Electroencephalographic and Neurodiagnostic Findings.

    Science.gov (United States)

    Kurşun, Oğuzhan; Karataş, Hülya; Dericioğlu, Neşe; Saygi, Serap

    2016-09-01

    Specialized centers, in the management and surgical treatment of medically refractory epilepsy, emphasize the importance of differentiating the varieties of localization related epilepsies. There has been considerable recent interest in temporal and frontal lobe epileptic syndromes and less attention has been paid to parietal and occipital lobe epilepsies. Here we report the clinical, electroencephalographic and neuroimaging characteristics of 46 patients with medically refractory lesional parietal lobe epilepsy who have been followed up for 1-10 years. In this study auras were reported in 78.3% of the patients and included sensory symptoms (72.2%), headache (36.1%), nausea and vomiting (36.1%), psychic symptoms (36.1%) and visual symptoms (16.6%). The most common ictal behavioral changes were paresthesia (69.6%) and focal clonic activity (39.1%). Tonic posture, various automatisms, head deviation, staring, sensation of pain and speech disturbances occurred to a lesser extent. Simple partial seizures were present in 69.6%. Complex partial seizures occurred in 43.5% and secondary generalized tonic clonic seizures were reported in 58.7% of the patients. Interictal routine EEG disclosed abnormal background activity in 1/3 of the patients. Nonlocalising epileptiform abnormalities were found in 34.8% of the patients. EEG findings were normal in 34.8% of the patients. The most common presumed etiologic factors were as follows: posttraumatic encephalomalacia, stroke, tumor, malformation of cortical development, atrophy, and arteriovenous malformation. Clinical, electrophysiological and neuroimaging features of the lesional symptomatic partial epilepsy patients may help us to localize the seizure focus in some patients with cryptogenic partial epilepsy. So that, the timing decision of the parietal lobe sampling with more invasive techniques like intracranial electrodes prior to epilepsy surgery would be easier.

  8. Parietal transcranial direct current stimulation modulates primary motor cortex excitability.

    Science.gov (United States)

    Rivera-Urbina, Guadalupe Nathzidy; Batsikadze, Giorgi; Molero-Chamizo, Andrés; Paulus, Walter; Kuo, Min-Fang; Nitsche, Michael A

    2015-03-01

    The posterior parietal cortex is part of the cortical network involved in motor learning and is structurally and functionally connected with the primary motor cortex (M1). Neuroplastic alterations of neuronal connectivity might be an important basis for learning processes. These have however not been explored for parieto-motor connections in humans by transcranial direct current stimulation (tDCS). Exploring tDCS effects on parieto-motor cortical connectivity might be functionally relevant, because tDCS has been shown to improve motor learning. We aimed to explore plastic alterations of parieto-motor cortical connections by tDCS in healthy humans. We measured neuroplastic changes of corticospinal excitability via motor evoked potentials (MEP) elicited by single-pulse transcranial magnetic stimulation (TMS) before and after tDCS over the left posterior parietal cortex (P3), and 3 cm posterior or lateral to P3, to explore the spatial specificity of the effects. Furthermore, short-interval intracortical inhibition/intracortical facilitation (SICI/ICF) over M1, and parieto-motor cortical connectivity were obtained before and after P3 tDCS. The results show polarity-dependent M1 excitability alterations primarily after P3 tDCS. Single-pulse TMS-elicited MEPs, M1 SICI/ICF at 5 and 7 ms and 10 and 15 ms interstimulus intervals (ISIs), and parieto-motor connectivity at 10 and 15 ms ISIs were all enhanced by anodal stimulation. Single pulse-TMS-elicited MEPs, and parieto-motor connectivity at 10 and 15 ms ISIs were reduced by cathodal tDCS. The respective corticospinal excitability alterations lasted for at least 120 min after stimulation. These results show an effect of remote stimulation of parietal areas on M1 excitability. The spatial specificity of the effects and the impact on parietal cortex-motor cortex connections suggest a relevant connectivity-driven effect.

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

    Science.gov (United States)

    Knaus, Tracey A.; Tager-Flusberg, Helen; Foundas, Anne L.

    2012-01-01

    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. PMID:22713374

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Hereditary cranium bifidum persisting as enlarged parietal foramina (Catlin marks) on cephalometric radiographs.

    Science.gov (United States)

    Mupparapu, Muralidhar; Binder, Robert E; Duarte, Fernando

    2006-06-01

    Cranium bifidum occultum is a rare skull ossification disorder referred to as the Catlin mark characterized by ossification defects in the parietal bones. Evidence suggests that this condition has a strong genetic heterogenicity. It is believed that, as calvarial growth continues, ossification in parietal bones fills these defects, and they can remain as parietal foramina on either side of the sagittal suture. During the conversion phase of cranium bifidum to the persistent parietal foramen, there will be periods when the brain is unprotected because of the delay in the ossification of the parietal bones. This report describes cranium bifidum occultum diagnosed as an incidental finding in a 14-year-old boy who initially had large bilateral unossified parietal bones and many congenital abnormalities. The patient underwent various surgical procedures over 6 years for the correction of cleft lip and palate. With craniofacial corrections and orthodontic treatment, the patient now has stable dentition and a firm palate with most of the parietal bones ossified. Cranioplasty was not recommended by his family physician after consultation with a neurosurgeon. Orthodontists should be familiar with this genetic abnormality because it causes delay in parietal bone ossification, and they should be able to distinguish between anatomic parietal foramina and enlarged parietal foramina (persistent unossified areas of cranium bifidum occultum), especially when craniofacial abnormalities are noticed.

  12. Cortical projections to the superior colliculus in tree shrews (Tupaia belangeri).

    Science.gov (United States)

    Baldwin, Mary K L; Wei, Haiyang; Reed, Jamie L; Bickford, Martha E; Petry, Heywood M; Kaas, Jon H

    2013-05-01

    The visuomotor functions of the superior colliculus depend not only on direct inputs from the retina, but also on inputs from neocortex. As mammals vary in the areal organization of neocortex, and in the organization of the number of visual and visuomotor areas, patterns of corticotectal projections vary. Primates in particular have a large number of visual areas projecting to the superior colliculus. As tree shrews are close relatives of primates, and they are also highly visual, we studied the distribution of cortical neurons projecting to the superior colliculus by injecting anatomical tracers into the colliculus. Since projections from visuotopically organized visual areas are expected to match the visuotopy of the superior colliculus, injections at different retinotopic locations in the superior colliculus provide information about the locations and organization of topographic areas in extrastriate cortex. Small injections in the superior colliculus labeled neurons in locations within areas 17 (V1) and 18 (V2) that are consistent with the known topography of these areas and the superior colliculus. In addition, the separate locations of clusters of labeled cells in temporal visual cortex provide evidence for five or more topographically organized areas. Injections that included deeper layers of the superior colliculus also labeled neurons in medial frontal cortex, likely in premotor cortex. Only occasional labeled neurons were observed in somatosensory or auditory cortex. Regardless of tracer injection location, we found that, unlike primates, a substantial projection to the superior colliculus from posterior parietal cortex is not a characteristic of tree shrews.

  13. Sobredentadura total superior implantosoportada

    Directory of Open Access Journals (Sweden)

    Luis Orlando Rodríguez García

    2010-06-01

    Full Text Available Se presenta un caso de un paciente desdentado total superior, rehabilitado en la consulta de implantología de la Clínica "Pedro Ortiz" del municipio Habana del Este en Ciudad de La Habana, Cuba, en el año 2009, mediante prótesis sobre implantes osteointegrados, técnica que se ha incorporado a la práctica estomatológica en Cuba como alternativa al tratamiento convencional en los pacientes desdentados totales. Se siguió un protocolo que comprendió una fase quirúrgica, procedimiento con o sin realización de colgajo y carga precoz o inmediata. Se presenta un paciente masculino de 56 años de edad, que acudió a la consulta multidisciplinaria, preocupado, porque se le habían elaborado tres prótesis en los últimos dos años y ninguna reunía los requisitos de retención que él necesitaba para sentirse seguro y cómodo con las mismas. El resultado final fue la satisfacción total del paciente, con el mejoramiento de la calidad estética y funcional.

  14. The role of human parietal area 7A as a link between sequencing in hand actions and in overt speech production

    Directory of Open Access Journals (Sweden)

    Stefan eHeim

    2012-12-01

    Full Text Available Research on the evolutionary basis of the human language faculty has proposed the mirror neuron system as a link between motor processing and speech development. Consequently, most work has focussed on the left inferior frontal cortex, in particular Broca's region, and the left inferior parietal cortex. However, the direct link between planning of hand motor and speech actions remains to be elucidated. Thus, the present study investigated whether sequencing of hand motor actions vs. speech motor actions has a common neural denominator. For the hand motor task, 25 subjects performed single, repeated, or sequenced button presses with either the left or right hand. The speech task was in analogy; the same subjects produced the syllable "po" once or repeatedly, or a sequence of different syllables (po-pi-po. Speech motor vs. hand motor effectors resulted in increased perisylvian activation including Broca's region (left area 44 and areas medially adjacent to left area 45. In contrast, common activation for sequenced vs. repeated production of button presses and syllables revealed the effector-independent involvement of left area 7A in the superior parietal lobule (SPL in sequencing. These data demonstrate that sequencing of vocal gestures, an important precondition for ordered utterances and ultimately human speech, shares area 7A, rather than inferior parietal regions, as a common cortical module with hand motor sequencing. Interestingly, area 7A has previously also been shown to be involved in the observation of hand and non-hand actions. In combination with the literature, the present data thus suggest a distinction between area 44, which is specifically recruited for (cognitive aspects of speech, and SPL area 7A for general aspects of motor sequencing. In sum, the study demonstrates a yet little considered role of the superior parietal lobule in the origins of speech, and may be discussed in the light of embodiment of speech and language in the

  15. Asymmetries in numerical density of pyramidal neurons in the fifth layer of the human posterior parietal cortex

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    Đukić-Macut Nataša

    2012-01-01

    Full Text Available Background/Aim. Both superior parietal lobule (SPL of dorsolateral hemispheric surface and precuneus (PEC of medial surface are the parts of posterior parietal cortex. The aim of this study was to determine the numerical density (NV of pyramidal neurons in the layer V of SPL and PEC and their potential differences. Methods. From 20 (40 hemispheres formaline fixed human brains (both sexes; 27- 65 years tissue blocks from SPL and PEC from the left and right hemisphere were used. According to their size the brains were divided into two groups, the group I with the larger left (15 brains and the group II with the larger right hemisphere (5 brains. Serial Nissl sections (5 μm of the left and right SPL and PEC were used for stereological estimation of NV of the layer V pyramidal neurons. Results. NV of pyramidal neurons in the layer V in the left SPL of brains with larger left hemispheres was significantly higher than in the left SPL of brains with larger right hemisphere. Comparing sides in brains with larger left hemisphere, the left SPL had higher NV than the right one, and then the left PEC, and the right SPL had significantly higher NV than the right PEC. Comparing sides in brains with the larger right hemisphere, the left SPL had significantly higher NV than left PEC, but the right SPL had significantly higher NV than left SPL and the right PEC. Conclusion. Generally, there is an inverse relationship of NV between the medial and lateral areas of the human posterior parietal cortex. The obtained values were different between the brains with larger left and right hemispheres, as well as between the SPL and PEC. In all the comparisons the left SPL had the highest values of NV of pyramidal neurons in the layer V (4771.80 mm-3, except in brains with the larger right hemisphere.

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

    Science.gov (United States)

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

    2014-01-01

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

  17. Right parietal cortex mediates recognition memory for melodies.

    Science.gov (United States)

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

    2015-07-01

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

  18. 'How many' and 'how much' dissociate in the parietal lobe.

    Science.gov (United States)

    Lecce, Francesca; Walsh, Vincent; Didino, Daniele; Cappelletti, Marinella

    2015-12-01

    We investigated whether two features that are fundamental for quantity processing, namely numerosity and continuous quantity - or 'how many' versus 'how much' - may dissociate in the parietal lobe. Fourteen mathematically-normal participants performed a well-established numerosity discrimination task after receiving continuous theta burst transcranial magnetic stimulation (TBS) over the left or right intraparietal sulcus (IPS) or the Vertex. We performed a detailed analysis of accuracy (based on the Weber Fraction, wf), which distinguished between trials in which numerosity was anti-correlated or 'incongruent' to other continuous measures of quantity, and trials in which numerosity and other continuous features were 'congruent'. Congruent trials can be processed by integrating numerosity or continuous quantity features like cumulative area since they correlate. Instead incongruent trials can only be processed based on numerosity and requires inhibiting cumulative area or other continuous quantity features like dot size and would lead to incorrect judgment if these features are used as a proxy for numerosity. We found an increase of wf, i.e., weakened numerosity processing in incongruent but not congruent trials following left IPS-TBS, which suggests that numerosity processing was impaired while continuous quantity processing remained unchanged. Moreover, wf increased in congruent but not in incongruent trials following right IPS stimulation. We concluded that left and right parietal are respectively critical for numerosity discrimination, i.e., 'how many' or alternatively for response selection, and for integrating numerosity and continuous quantity features. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Sense of agency is related to gamma band coupling in an inferior parietal-preSMA circuitry

    DEFF Research Database (Denmark)

    Ritterband-Rosenbaum, Anina; Nielsen, Jens Bo; Christensen, Mark Schram

    2014-01-01

    In the present study we tested whether sense of agency (SoA) is reflected by changes in coupling between right medio-frontal/supplementary motor area (SMA) and inferior parietal cortex (IPC). Twelve healthy adult volunteers participated in the study. They performed a variation of a line-drawing t......In the present study we tested whether sense of agency (SoA) is reflected by changes in coupling between right medio-frontal/supplementary motor area (SMA) and inferior parietal cortex (IPC). Twelve healthy adult volunteers participated in the study. They performed a variation of a line...... as to the agent of the movement and they reported SoA in approximately 50% of trials when the movement was computer-generated. We tested whether IPC-preSMA coupling was associated with SoA, using dynamic causal modeling (DCM) for induced responses (Chen et al., 2008; Herz et al., 2012). Nine different DCMs were...... constructed for the early and late phases of the task, respectively. All models included two regions: a superior medial gyrus (preSMA) region and a right supramarginal gyrus (IPC) region. Bayesian models selection (Stephan et al., 2009) favored a model with input to IPC and modulation of the forward...

  20. Abnormal temporal and parietal magnetic activations during the early stages of theory of mind in schizophrenic patients.

    Science.gov (United States)

    Vistoli, Damien; Brunet-Gouet, Eric; Lemoalle, Amelia; Hardy-Baylé, Marie-Christine; Passerieux, Christine

    2011-01-01

    Schizophrenia is associated with abnormal cortical activation during theory of mind (ToM), as demonstrated by several fMRI or PET studies. Electrical and temporal characteristics of these abnormalities, especially in the early stages, remain unexplored. Nineteen medicated schizophrenic patients and 21 healthy controls underwent magnetoencephalography (MEG) recording to measure brain response evoked by nonverbal stimuli requiring mentalizing. Three conditions based on comic-strips were contrasted: attribution of intentions to others (AI), physical causality with human characters (PCCH), and physical causality with objects (PCOB). Minimum norm localization was performed in order to select regions of interest (ROIs) within bilateral temporal and parietal regions that showed significant ToM-related activations in the control group. Time-courses of each ROI were compared across group and condition. Reduced cortical activation within the 200 to 600 ms time-window was observed in the selected regions in patients. Significant group by condition interactions (i.e., reduced modulation in patients) were found in right posterior superior temporal sulcus, right temporoparietal junction, and right inferior parietal lobule during attribution of intentions. As in healthy controls, the presence of characters elicited activation in patients' left posterior temporal regions and temporoparietal junction. No group difference on evoked responses' latencies in AI was found. In conclusion, ToM processes in the early stages are functionally impaired in schizophrenia. MEG provides a promising means to refine our knowledge on schizophrenic social cognitive disorders.

  1. Sex Differences in Parietal Lobe Morphology: Relationship to Mental Rotation Performance

    OpenAIRE

    Koscik, Tim; O’Leary, Dan; Moser, David J; Andreasen, Nancy C; Nopoulos, Peg

    2008-01-01

    Structural magnetic resonance imaging (MRI) studies of the human brain have reported evidence for sexual dimorphism. In addition to sex differences in overall cerebral volume, differences in the proportion of gray matter (GM) to white matter (WM) volume have been observed, particularly in the parietal lobe. To our knowledge there have been no studies examining the relationship between the sex differences in parietal lobe structure and function. The parietal lobe is thought to be involved in s...

  2. [Mitral surgery by superior biatrial septotomy].

    Science.gov (United States)

    Saade, A; Delepine, G; Lemaitre, C; Baehrel, B

    1995-01-01

    The superior biatrial septotomy approach consists of two semicircular right atrial and septal incisions joined at the superior end of the interatrial septum and extended across the dome of the left atrium, allowing exposure of the mitral valve by reflecting the ventricular side using stay sutures. From 1991 to 1993, 81 patients underwent mitral valve surgery by this technic. Mitral valve operation was combined with other cardiac procedures in 30 patients (37%) and was performed as a second operation in 21 patients (25.9%). Duration of cardiopulmonary bypass and aortic occlusion was not significantly different from that of patients operated via a conventional left atrial approach. The five hospital deaths (6.2%) were not related to this operative approach. Only 2 patients (3.3%) with preoperative in sinus rythm were discharged in atrial fibrillation after operation. In one patient (1.6%), atrioventricular block appeared at late follow-up. There were no cases of bleeding, atrioventricular nodal dysfunction or intra-atrial shunting related to the approach. This approach provides excellent exposure of the mitral valve even in unfavorable situations such as a small left atrium, dense adhesions from previous procedures or a previously implanted aortic prosthesis, without damage to various cardiac structures due to excessive traction. No retractor or vena cava repair are required. These data support a wide application of the superior biatrial septotomy approach in mitral valve surgery.

  3. Superior Sagittal Sinus Thrombosis Complicating Typhoid Fever in a Teenager

    Directory of Open Access Journals (Sweden)

    P. O. Okunola

    2012-01-01

    Full Text Available Cerebral venous sinus (sinovenous thrombosis (CSVT is a rare life-threatening disorder in childhood that is often misdiagnosed. CSVT encompasses cavernous sinus thrombosis, lateral sinus thrombosis, and superior sagittal sinus thrombosis (SSST. We present an adolescent girl who was well until two weeks earlier when she had a throbbing frontal headache and fever with chills; she later had dyspnoea, jaundice, melena stool, multiple seizures, nuchal rigidity, and monoparesis of the right lower limb a day before admission. Urine test for Salmonella typhi Vi antigen was positive, and Widal reaction was significant. Serial cranial computerized tomography scans revealed an expanding hypodense lesion in the parafalcine region consistent with SSST or a parasagittal abscess. Inadvertent left parietal limited craniectomy confirmed SSST. She recovered completely with subsequent conservative management. Beyond neuropsychiatric complications of Typhoid fever, CSVT should be highly considered when focal neurologic deficits are present.

  4. A parietal memory network revealed by multiple MRI methods.

    Science.gov (United States)

    Gilmore, Adrian W; Nelson, Steven M; McDermott, Kathleen B

    2015-09-01

    The manner by which the human brain learns and recognizes stimuli is a matter of ongoing investigation. Through examination of meta-analyses of task-based functional MRI and resting state functional connectivity MRI, we identified a novel network strongly related to learning and memory. Activity within this network at encoding predicts subsequent item memory, and at retrieval differs for recognized and unrecognized items. The direction of activity flips as a function of recent history: from deactivation for novel stimuli to activation for stimuli that are familiar due to recent exposure. We term this network the 'parietal memory network' (PMN) to reflect its broad involvement in human memory processing. We provide a preliminary framework for understanding the key functional properties of the network. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Herpes Simplex Encephalitis of the Parietal Lobe: A Rare Presentation

    Science.gov (United States)

    Tkachenko, Lara; Moisi, Marc; Rostad, Steven; Umeh, Randle; Zwillman, Michael E; Tubbs, R. Shane; Page, Jeni; Newell, David W.; Delashaw, Johnny B

    2016-01-01

    A 69-year-old female with a history of breast cancer and hypertension presented with a rare case of herpes simplex encephalitis (HSE) isolated to her left parietal lobe. The patient’s first biopsy was negative for herpes simplex virus (HSV) I/II antigens, but less than two weeks later, the patient tested positive on repeat biopsy. This initial failure to detect the virus and the similarities between HSE and symptoms of intracranial hemorrhage (ICH) suggests repeat testing for HSV in the presence of ICH. Due to the frequency of patients with extra temporal HSE, a diagnosis of HSE should be more readily considered, particularly when a patient may not be improving and a concrete diagnosis has not been solidified. PMID:27774355

  6. Herpes Simplex Encephalitis of the Parietal Lobe: A Rare Presentation.

    Science.gov (United States)

    Fisahn, Christian; Tkachenko, Lara; Moisi, Marc; Rostad, Steven; Umeh, Randle; Zwillman, Michael E; Tubbs, R Shane; Page, Jeni; Newell, David W; Delashaw, Johnny B

    2016-09-16

    A 69-year-old female with a history of breast cancer and hypertension presented with a rare case of herpes simplex encephalitis (HSE) isolated to her left parietal lobe. The patient's first biopsy was negative for herpes simplex virus (HSV) I/II antigens, but less than two weeks later, the patient tested positive on repeat biopsy. This initial failure to detect the virus and the similarities between HSE and symptoms of intracranial hemorrhage (ICH) suggests repeat testing for HSV in the presence of ICH. Due to the frequency of patients with extra temporal HSE, a diagnosis of HSE should be more readily considered, particularly when a patient may not be improving and a concrete diagnosis has not been solidified.

  7. Scalp Medical Tattooing Technique to Camouflage Bifid Parietal Whorls

    Science.gov (United States)

    You, Seung Hyun

    2016-01-01

    Background: To the best of the authors’ knowledge, no reports have described cosmetic problems arising from the hair direction around the parietal whorl (PW). This study was performed to evaluate the efficacy of scalp medical tattooing technique for camouflaging bifid PWs. Methods: We retrospectively examined the outcomes of scalp medical tattooing in 38 patients who were admitted for camouflage of a bifid PW. Results: All patients’ cosmetic appearance was judged, by both the patients and the surgeon, to be markedly improved. No specific complications occurred, such as infection, hair loss in the operative field, or other problems. Conclusion: Scalp medical tattooing appears to be an effective method that helps to camouflage the see-through appearance of bifid PWs. PMID:27200232

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

    Science.gov (United States)

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

    2014-01-01

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

  9. Damage Distributions

    DEFF Research Database (Denmark)

    Lützen, Marie

    2001-01-01

    the damage location, the damage sizes and the main particulars of the struck vessel. From the numerical simulation and the analyse of the damage statistics it is found that the current formulation from the IMO SLF 43/3/2 can be used as basis for determination of the p-, r-, and v-factors. Expressions...... and methods of calculation have been discussed. The damage distributions for the different vessels have been compared and analyses regarding relations between damage parameters and main particulars have been performed. The damage statistics collected in work package 1 have been analysed for relations between...... for the distribution of the non-dimensional damage location, the non-dimensional damage length and the non-dimensional penetrations have been derived. These distributions have been used as basis for a proposal for the p- and r-factors. Two proposals for the v-factor have been performed using the damage statistics...

  10. Subcortical mapping of calculation processing in the right parietal lobe.

    Science.gov (United States)

    Della Puppa, Alessandro; De Pellegrin, Serena; Lazzarini, Anna; Gioffrè, Giorgio; Rustemi, Oriela; Cagnin, Annachiara; Scienza, Renato; Semenza, Carlo

    2015-05-01

    Preservation of calculation processing in brain surgery is crucial for patients' quality of life. Over the last decade, surgical electrostimulation was used to identify and preserve the cortical areas involved in such processing. Conversely, subcortical connectivity among different areas implicated in this function remains unclear, and the role of surgery in this domain has not been explored so far. The authors present the first 2 cases in which the subcortical functional sites involved in calculation were identified during right parietal lobe surgery. Two patients affected by a glioma located in the right parietal lobe underwent surgery with the aid of MRI neuronavigation. No calculation deficits were detected during preoperative assessment. Cortical and subcortical mapping were performed using a bipolar stimulator. The current intensity was determined by progressively increasing the amplitude by 0.5-mA increments (from a baseline of 1 mA) until a sensorimotor response was elicited. Then, addition and multiplication calculation tasks were administered. Corticectomy was performed according to both the MRI neuronavigation data and the functional findings obtained through cortical mapping. Direct subcortical electrostimulation was repeatedly performed during tumor resection. Subcortical functional sites for multiplication and addition were detected in both patients. Electrostimulation interfered with calculation processing during cortical mapping as well. Functional sites were spared during tumor removal. The postoperative course was uneventful, and calculation processing was preserved. Postoperative MRI showed complete resection of the tumor. The present preliminary study shows for the first time how functional mapping can be a promising method to intraoperatively identify the subcortical functional sites involved in calculation processing. This report therefore supports direct electrical stimulation as a promising tool to improve the current knowledge on

  11. Insights from Neuropsychology: Pinpointing the role of the Posterior Parietal Cortex in Episodic and Working Memory

    Directory of Open Access Journals (Sweden)

    Marian E. Berryhill

    2012-06-01

    Full Text Available The role of posterior parietal cortex (PPC in various forms of memory is a current topic of interest in the broader field of cognitive neuroscience. This large cortical region has been linked with a wide range of mnemonic functions affecting each stage of memory processing: encoding, maintenance and retrieval. Yet, the precise role of the PPC in memory remains mysterious and controversial. Progress in understanding PPC function will require researchers to incorporate findings in a convergent manner from multiple experimental techniques rather than emphasizing a particular type of data. To facilitate this process, here, we review findings from the human neuropsychological research and examine the consequences to memory following PPC damage. Recent patient-based research findings have investigated two typically disconnected fields: working memory and episodic memory. The findings from patient participants with unilateral and bilateral PPC lesions performing diverse experimental paradigms are summarized. These findings are then related to findings from other techniques including neurostimulation (TMS and tDCS and the influential and more abundant functional neuroimaging literature. We then review the strengths and weaknesses of hypotheses proposed to account for PPC function in these forms of memory. Finally, we address what missing evidence is needed to clarify the role(s of the PPC in memory.

  12. The role of temporo-parietal junction (TPJ) in global Gestalt perception.

    Science.gov (United States)

    Huberle, Elisabeth; Karnath, Hans-Otto

    2012-07-01

    Grouping processes enable the coherent perception of our environment. A number of brain areas has been suggested to be involved in the integration of elements into objects including early and higher visual areas along the ventral visual pathway as well as motion-processing areas of the dorsal visual pathway. However, integration not only is required for the cortical representation of individual objects, but is also essential for the perception of more complex visual scenes consisting of several different objects and/or shapes. The present fMRI experiments aimed to address such integration processes. We investigated the neural correlates underlying the global Gestalt perception of hierarchically organized stimuli that allowed parametrical degrading of the object at the global level. The comparison of intact versus disturbed perception of the global Gestalt revealed a network of cortical areas including the temporo-parietal junction (TPJ), anterior cingulate cortex and the precuneus. The TPJ location corresponds well with the areas known to be typically lesioned in stroke patients with simultanagnosia following bilateral brain damage. These patients typically show a deficit in identifying the global Gestalt of a visual scene. Further, we found the closest relation between behavioral performance and fMRI activation for the TPJ. Our data thus argue for a significant role of the TPJ in human global Gestalt perception.

  13. Parietal Epithelial Cell Activation Marker in Early Recurrence of FSGS in the Transplant

    NARCIS (Netherlands)

    Fatima, H.; Moeller, M.J.; Smeets, B.; Yang, H.C.; D'Agati, V.D.; Alpers, C.E.; Fogo, A.B.

    2012-01-01

    BACKGROUND AND OBJECTIVES: Podocyte loss is key in glomerulosclerosis. Activated parietal epithelial cells are proposed to contribute to pathogenesis of glomerulosclerosis and may serve as stem cells that can transition to podocytes. CD44 is a marker for activated parietal epithelial cells. This stu

  14. 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...

  15. Mapping different intra-hemispheric parietal-motor networks using twin Coil TMS

    DEFF Research Database (Denmark)

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

    2013-01-01

    Accumulating evidence suggests anatomical and functional differences in connectivity between the anterior and posterior parts of the inferior-parietal lobule (IPL) and the frontal motor areas.......Accumulating evidence suggests anatomical and functional differences in connectivity between the anterior and posterior parts of the inferior-parietal lobule (IPL) and the frontal motor areas....

  16. Dynamic CT Features of a hemangioma originating from the parietal pleura: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Kyung; Park, Jai Soung; Park, Sang Hyun; Cha, Jang Gyu; Shin, Hwa Kyoon; Koh, Eun Suk [Soonchunhyang Univ. Bucheon Hospital/Soonchunhyang Univ. College of Medicine, Bucheon (Korea, Republic of)

    2012-06-15

    A pleural hemangioma is an extremely rare disease. Few studies have reported on the radiologic appearance of chest wall hemangioma, especially originating from the parietal pleura. We describe a 45 year old female patient with a soft tissue mass in the parietal pleura showing centripetal enhancement on dynamic CT. The patient underwent surgery and the pathologic examination confirmed the presence of a capillary hemangioma.

  17. The Contribution of the Inferior Parietal Cortex to Spoken Language Production

    Science.gov (United States)

    Geranmayeh, Fatemeh; Brownsett, Sonia L. E.; Leech, Robert; Beckmann, Christian F.; Woodhead, Zoe; Wise, Richard J. S.

    2012-01-01

    This functional MRI study investigated the involvement of the left inferior parietal cortex (IPC) in spoken language production (Speech). Its role has been apparent in some studies but not others, and is not convincingly supported by clinical studies as they rarely include cases with lesions confined to the parietal lobe. We compared Speech with…

  18. The Role of Right and Left Parietal Lobes in the Conceptual Processing of Numbers

    Science.gov (United States)

    Cappelletti, Marinella; Lee, Hwee Ling; Freeman, Elliot D.; Price, Cathy J.

    2010-01-01

    Neuropsychological and functional imaging studies have associated the conceptual processing of numbers with bilateral parietal regions (including intraparietal sulcus). However, the processes driving these effects remain unclear because both left and right posterior parietal regions are activated by many other conceptual, perceptual, attention,…

  19. The Impact of Auditory Working Memory Training on the Fronto-Parietal Working Memory Network

    Directory of Open Access Journals (Sweden)

    Julia eSchneiders

    2012-06-01

    Full Text Available Working memory training has been widely used to investigate working memory processes. We have shown previously that visual working memory benefits only from intra-modal visual but not from across-modal auditory working memory training. In the present functional magnetic resonance imaging study we examined whether auditory working memory processes can also be trained specifically and which training-induced activation changes accompany theses effects. It was investigated whether working memory training with strongly distinct auditory materials transfers exclusively to an auditory (intra-modal working memory task or whether it generalizes to an (across-modal visual working memory task. We used an adaptive n-back training with tonal sequences and a passive control condition. The memory training led to a reliable training gain. Transfer effects were found for the (intra-modal auditory but not for the (across-modal visual 2-back task. Training-induced activation changes in the auditory 2-back task were found in two regions in the right inferior frontal gyrus. These effects confirm our previous findings in the visual modality and extends intra-modal effects to the auditory modality. These results might reflect increased neural efficiency in auditory working memory processes as in the right inferior frontal gyrus is frequently found in maintaining modality-specific auditory information. By this, these effects are analogical to the activation decreases in the right middle frontal gyrus for the visual modality in our previous study. Furthermore, task-unspecific (across-modal activation decreases in the visual and auditory 2-back task were found in the right inferior parietal lobule and the superior portion of the right middle frontal gyrus reflecting less demands on general attentional control processes. These data are in good agreement with across-modal activation decreases within the same brain regions on a visual 2-back task reported previously.

  20. Parietal neural prosthetic control of a computer cursor in a graphical-user-interface task

    Science.gov (United States)

    Revechkis, Boris; Aflalo, Tyson NS; Kellis, Spencer; Pouratian, Nader; Andersen, Richard A.

    2014-12-01

    Objective. To date, the majority of Brain-Machine Interfaces have been used to perform simple tasks with sequences of individual targets in otherwise blank environments. In this study we developed a more practical and clinically relevant task that approximated modern computers and graphical user interfaces (GUIs). This task could be problematic given the known sensitivity of areas typically used for BMIs to visual stimuli, eye movements, decision-making, and attentional control. Consequently, we sought to assess the effect of a complex, GUI-like task on the quality of neural decoding. Approach. A male rhesus macaque monkey was implanted with two 96-channel electrode arrays in area 5d of the superior parietal lobule. The animal was trained to perform a GUI-like ‘Face in a Crowd’ task on a computer screen that required selecting one cued, icon-like, face image from a group of alternatives (the ‘Crowd’) using a neurally controlled cursor. We assessed whether the crowd affected decodes of intended cursor movements by comparing it to a ‘Crowd Off’ condition in which only the matching target appeared without alternatives. We also examined if training a neural decoder with the Crowd On rather than Off had any effect on subsequent decode quality. Main results. Despite the additional demands of working with the Crowd On, the animal was able to robustly perform the task under Brain Control. The presence of the crowd did not itself affect decode quality. Training the decoder with the Crowd On relative to Off had no negative influence on subsequent decoding performance. Additionally, the subject was able to gaze around freely without influencing cursor position. Significance. Our results demonstrate that area 5d recordings can be used for decoding in a complex, GUI-like task with free gaze. Thus, this area is a promising source of signals for neural prosthetics that utilize computing devices with GUI interfaces, e.g. personal computers, mobile devices, and tablet

  1. Beyond natural numbers: negative number representation in parietal cortex.

    Science.gov (United States)

    Blair, Kristen P; Rosenberg-Lee, Miriam; Tsang, Jessica M; Schwartz, Daniel L; Menon, Vinod

    2012-01-01

    Unlike natural numbers, negative numbers do not have natural physical referents. How does the brain represent such abstract mathematical concepts? Two competing hypotheses regarding representational systems for negative numbers are a rule-based model, in which symbolic rules are applied to negative numbers to translate them into positive numbers when assessing magnitudes, and an expanded magnitude model, in which negative numbers have a distinct magnitude representation. Using an event-related functional magnetic resonance imaging design, we examined brain responses in 22 adults while they performed magnitude comparisons of negative and positive numbers that were quantitatively near (difference 6). Reaction times (RTs) for negative numbers were slower than positive numbers, and both showed a distance effect whereby near pairs took longer to compare. A network of parietal, frontal, and occipital regions were differentially engaged by negative numbers. Specifically, compared to positive numbers, negative number processing resulted in greater activation bilaterally in intraparietal sulcus (IPS), middle frontal gyrus, and inferior lateral occipital cortex. Representational similarity analysis revealed that neural responses in the IPS were more differentiated among positive numbers than among negative numbers, and greater differentiation among negative numbers was associated with faster RTs. Our findings indicate that despite negative numbers engaging the IPS more strongly, the underlying neural representation are less distinct than that of positive numbers. We discuss our findings in the context of the two theoretical models of negative number processing and demonstrate how multivariate approaches can provide novel insights into abstract number representation.

  2. The posterior parietal cortex remaps touch into external space.

    Science.gov (United States)

    Azañón, Elena; Longo, Matthew R; Soto-Faraco, Salvador; Haggard, Patrick

    2010-07-27

    Localizing tactile events in external space is required for essential functions such as orienting, haptic exploration, and goal-directed action in peripersonal space. In order to map somatosensory input into a spatiotopic representation, information about skin location must be integrated with proprioceptive information about body posture. We investigated the neural bases of this tactile remapping mechanism in humans by disrupting neural activity in the putative human homolog of the monkey ventral intraparietal area (hVIP), within the right posterior parietal cortex (rPPC), which is thought to house external spatial representations. Participants judged the elevation of touches on their (unseen) forearm relative to touches on their face. Arm posture was passively changed along the vertical axis, so that elevation judgments required the use of an external reference frame. Single-pulse transcranial magnetic stimulation (TMS) over the rPPC significantly impaired performance compared to a control site (vertex). Crucially, proprioceptive judgments of arm elevation or tactile localization on the skin remained unaffected by rPPC TMS. This selective disruption of tactile remapping suggests a distinct computational process dissociable from pure proprioceptive and somatosensory localization. Furthermore, this finding highlights the causal role of human PPC, putatively VIP, in remapping touch into external space.

  3. Cyclodextrin modified PLLA parietal reinforcement implant with prolonged antibacterial activity.

    Science.gov (United States)

    Vermet, G; Degoutin, S; Chai, F; Maton, M; Flores, C; Neut, C; Danjou, P E; Martel, B; Blanchemain, N

    2017-02-12

    The use of textile meshes in hernia repair is widespread in visceral surgery. Though, mesh infection is a complication that may prolong the patient recovery period and consequently presents an impact on public health economy. Such concern can be avoided thanks to a local and extended antibiotic release on the operative site. In recent developments, poly-l-lactic acid (PLLA) has been used in complement of polyethyleneterephthalate (Dacron®) (PET) or polypropylene (PP) yarns in the manufacture of semi-resorbable parietal implants. The goal of the present study consisted in assigning drug reservoir properties and prolonged antibacterial effect to a 100% PLLA knit through its functionalization with a cyclodextrin polymer (polyCD) and activation with ciprofloxacin. The study focused i) on the control of degree of polyCD functionalization of the PLLA support and on its physical and biological characterization by Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC) and cell viability, ii) on the understanding of drug/meshes interaction using mathematic model and iii) on the correlation between drug release studies in phosphate buffer saline (PBS) and microbiological evaluation of meshes and release medium against E. coli and S. aureus. All above mentioned tests highlighted the contribution of polyCD on the improved performances of the resulting antibacterial implantable material.

  4. Morphological patterns of the intraparietal sulcus and the anterior intermediate parietal sulcus of Jensen in the human brain.

    Science.gov (United States)

    Zlatkina, Veronika; Petrides, Michael

    2014-12-22

    Distinct parts of the intraparietal sulcal cortex contribute to sensorimotor integration and visual spatial attentional processing. A detailed examination of the morphological relations of the different segments of the complex intraparietal sulcal region in the human brain in standard stereotaxic space, which is a prerequisite for detailed structure-to-function studies, is not available. This study examined the intraparietal sulcus (IPS) and the related sulcus of Jensen in magnetic resonance imaging brain volumes registered in the Montreal Neurological Institute stereotaxic space. It was demonstrated that the IPS is divided into two branches: the anterior ramus and the posterior ramus of the IPS, often separated by a submerged gyral passage. The sulcus of Jensen emerges between the anterior and posterior rami of the IPS, and its ventral end is positioned between the first and second caudal branches of the superior temporal sulcus. In a small number of brains, the sulcus of Jensen may merge superficially with the first caudal branch of the superior temporal sulcus. The above morphological findings are discussed in relation to previously reported functional neuroimaging findings and provide the basis for future exploration of structure-to-function relations in the posterior parietal region of individual subjects.

  5. Lightning activity during the 1999 Superior derecho

    Science.gov (United States)

    Price, Colin G.; Murphy, Brian P.

    2002-12-01

    On 4 July 1999, a severe convective windstorm, known as a derecho, caused extensive damage to forested regions along the United States/Canada border, west of Lake Superior. There were 665,000 acres of forest destroyed in the Boundary Waters Canoe Area Wilderness (BWCAW) in Minnesota and Quetico Provincial Park in Canada, with approximately 12.5 million trees blown down. This storm resulted in additional severe weather before and after the occurrence of the derecho, with continuous cloud-to-ground (CG) lightning occurring for more than 34 hours during its path across North America. At the time of the derecho the percentage of positive cloud-to-ground (+CG) lightning measured by the Canadian Lightning Detection Network (CLDN) was greater than 70% for more than three hours, with peak values reaching 97% positive CG lightning. Such high ratios of +CG are rare, and may be useful indicators of severe weather.

  6. Cortical Connectivity Maps Reveal Anatomically Distinct Areas in the Parietal Cortex of the Rat

    Directory of Open Access Journals (Sweden)

    Aaron eWilber

    2015-01-01

    Full Text Available A central feature of theories of spatial navigation involves the representation of spatial relationships between objects in complex environments. The parietal cortex has long been linked to the processing of spatial visual information and recent evidence from single unit recording in rodents suggests a role for this region in encoding egocentric and world-centered frames. The rat parietal cortex can be subdivided into up to four distinct rostral-caudal and medial-lateral regions, which includes a zone previously characterized as secondary visual cortex. At present, very little is known regarding the relative connectivity of these parietal subdivisions. Thus, we set out to map the connectivity of the entire anterior-posterior and medial-lateral span of this region. To do this we used anterograde and retrograde tracers in conjunction with open source neuronal segmentation and tracer detection tools to generate whole brain connectivity maps of parietal inputs and outputs. Our present results show that inputs to the parietal cortex varied significantly along the medial-lateral, but not the rostral-caudal axis. Specifically, retrosplenial connectivity is greater medially, but connectivity with visual cortex, though generally sparse, is more significant laterally. Finally, based on connection density, the connectivity between parietal cortex and hippocampus is indirect and likely achieved largely via dysgranular retrosplenial cortex. Thus, similar to primates, the parietal cortex of rats exhibits a difference in connectivity along the medial-lateral axis, which may represent functionally distinct areas.

  7. Development of a superior frontal-intraparietal network for visuo-spatial working memory.

    Science.gov (United States)

    Klingberg, Torkel

    2006-01-01

    Working memory capacity increases throughout childhood and adolescence, which is important for the development of a wide range of cognitive abilities, including complex reasoning. The spatial-span task, in which subjects retain information about the order and position of a number of objects, is a sensitive task to measure development of spatial working memory. This review considers results from previous neuroimaging studies investigating the neural correlates of this development. Older children and adolescents, with higher capacity, have been found to have higher brain activity in the intraparietal cortex and in the posterior part of the superior frontal sulcus, during the performance of working memory tasks. The structural maturation of white matter has been investigated by diffusion tensor magnetic resonance imaging (DTI). This has revealed several regions in the frontal lobes in which white matter maturation is correlated with the development of working memory. Among these is a superior fronto-parietal white matter region, located close to the grey matter regions that are implicated in the development of working memory. Furthermore, the degree of white matter maturation is positively correlated with the degree of cortical activation in the frontal and parietal regions. This suggests that during childhood and adolescence, there is development of networks related to specific cognitive functions, such as visuo-spatial working memory. These networks not only consist of cortical areas but also the white matter tracts connecting them. For visuo-spatial working memory, this network could consist of the superior frontal and intraparietal cortex.

  8. A Neuropsychological Examination of the Underlying Deficit in Attention Deficit Hyperactivity Disorder: Frontal Lobe Versus Right Parietal Lobe Theories.

    Science.gov (United States)

    Aman, Christine J.; Roberts, Ralph J., Jr.; Pennington, Bruce F.

    1998-01-01

    Examined front and right parietal lobe theories of attention deficit hyperactivity disorder (ADHD); subjects were 10- to 14-year-old boys with or without ADHD. Found that non-ADHD boys performed better on frontal- and parietal-domain tasks than unmedicated ADHD boys, unmedicated AHDH boys had greater impairments on frontal than parietal tasks, and…

  9. Isolation, culture and adenoviral transduction of parietal cells from mouse gastric mucosa

    Energy Technology Data Exchange (ETDEWEB)

    Gliddon, Briony L; Nguyen, Nhung V; Gunn, Priscilla A; Gleeson, Paul A; Driel, Ian R van [The Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Melbourne, Victoria 3010 (Australia)], E-mail: i.vandriel@unimelb.edu.au

    2008-09-01

    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 {approx}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{sup +}/K{sup +} 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{sup +}/K{sup +} 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{sup +}/K{sup +} 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 {approx}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{sup +}/K{sup +} ATPase which underpin the regulation of acid secretion.

  10. Effects of L-NAME on morphometric parameters of stomach parietal cells in pregnant rats

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Hossein Noori Mugahi

    2014-05-01

    Results: Results of this study after analysis showed the significant changes in parietal cells count (mean 61.3±4.32 and its diameters (mean 16.12±1.18 µm in L-NAME group in comparison to control and the sham groups in pregnant rats (P≤0.05. Conclusion: Results of this study showed L-NAME with effects on NO synthesis can reduce the count of parietal cells and increase its diameter in pregnant rats and has destructive effects on structure of stomach parietal cells in pregnancy rats.

  11. 75 FR 28542 - Superior Resource Advisory Committee

    Science.gov (United States)

    2010-05-21

    ... orient the new Superior Resource Advisory Committee members on their roles and responsibilities. DATES... of the roles and responsibilities of the Superior Resource Advisory Committee members; Election of... Forest Service Superior Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice...

  12. [The superior laryngeal nerve and the superior laryngeal artery].

    Science.gov (United States)

    Lang, J; Nachbaur, S; Fischer, K; Vogel, E

    1987-01-01

    Length, diameter and anastomoses of the nervus vagus and its ganglion inferius were measured 44 halved heads. On the average, 8.65 fiber bundles of the vagus nerve leave the retro-olivary area. In the area of the jugular foramen is the near superior ganglion of the 10th cranial nerve. In this area were found 1.48 (mean value) anastomoses with the 9th cranial nerve. 11.34 mm below the margo terminalis sigmoidea branches off the ramus internus of the accessory nerve which has a length of 9.75 mm. Further anastomoses with the 10th cranial nerve were found. The inferior ganglion of the 10th nerve had a length of 25.47 mm and a diameter of 3.46 mm. Five mm below the ganglion the 10th nerve had a width of 2.9 and a thickness of 1.5 mm. The mean length of the superior sympathetic ganglion was 26.6 mm, its width 7.2 and its thickness 3.4 mm. In nearly all specimens anastomoses of the superior sympathetic ganglion with the ansa cervicalis profunda and the inferior ganglion of the 10th cranial nerve were found. The superior laryngeal nerve branches off about 36 mm below the margo terminalis sigmoidea. The width of this nerve was 1.9 mm, its thickness 0.8 mm on the right and 1.0 mm on the left side. The division in the internal and external rami was found about 21 mm below its origin. Between the n. vagus and thyreohyoid membrane the ramus internus had a length of 64 mm, the length of external ramus between the vagal nerve and the inferior pharyngeal constrictor muscle was 89 mm. Its mean length below the thyreopharyngeal part was 10.7 mm, 8.6 branchlets to the cricothyroid muscle were counted. The superior laryngeal artery had its origin in 80% of cases in the superior thyroideal artery, in 6.8% this vessel was a branch of the external carotid artery. Its average outer diameter was 1.23 mm on the right side and 1.39 mm on the left. The length of this vessel between its origin and the thyreohyoid membrane was 34 mm. In 7% on the right side and in 13% on the left, the superior

  13. Abstract categories of functions in anterior parietal lobe.

    Science.gov (United States)

    Leshinskaya, Anna; Caramazza, Alfonso

    2015-09-01

    Knowledge of function is critical for selecting objects to meet action goals, even when the affordances of those objects are not mechanical-for instance, both a painting and a vase can decorate a room. To identify neural representations of such abstract function concepts, we asked participants in an fMRI scanner to view a variety of objects and evaluate their utility to each of four goals (two Decoration goals: dress up for a night out and decorate a house, and two Protection goals: protect your body from the cold and keep objects dry in a flooded basement). These task conditions differed in the kind of functional evaluation participants had to perform over objects, but did not vary in the objects themselves. We performed a searchlight multivariate pattern analysis to identify cortical representations in which neural patterns were more similar for the pairs of similar-goal than dissimilar-goal task conditions (Decorate vs. Protect). We report such effects in anterior inferior parietal lobe (aIPL) close to regions typically reported for processing tool-related actions, and thought to be important for representing how they are manipulated. However, the current study design fully controlled for manipulation similarity, which predicted orthogonal relationships among the conditions. We conclude that the aIPL likely has nearby, but distinct, representations of both manipulation and function knowledge, and thereby may have a broader role in understanding how objects can be used, representing not just physical affordances but also abstract functional criteria such as esthetic value or purpose categories such as decorate. This pattern of localization has implications for how semantic knowledge is organized in the brain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. What are Millian Qualitative Superiorities?

    Directory of Open Access Journals (Sweden)

    Jonathan Riley

    2008-04-01

    Full Text Available In an article published in Prolegomena 2006, Christoph Schmidt-Petri has defended his interpretation and attacked mine of Mill’s idea that higher kinds of pleasure are superior in quality to lower kinds, regardless of quantity. Millian qualitative superiorities as I understand them are infinite superiorities. In this paper, I clarify my interpretation and show how Schmidt-Petri has misrepresented it and ignored the obvious textual support for it. As a result, he fails to understand how genuine Millian qualitative superiorities determine the novel structure of Mill’s pluralistic utilitarianism, in which a social code of justice that distributes equal rights and duties takes absolute priority over competing considerations. Schmidt-Petri’s own interpretation is a non-starter, because it does noteven recognize that Mill is talking about different kinds of pleasant feelings, such that the higher kinds are intrinsically more valuable than the lower. I conclude by outlining why my interpretation is free of any metaphysical commitment to the “essence” of pleasure.

  15. Isolated superior mesenteric artery dissection

    Directory of Open Access Journals (Sweden)

    Lalitha Palle

    2010-01-01

    Full Text Available Isolated superior mesenteric artery (SMA dissection without involvement of the aorta and the SMA origin is unusual. We present a case of an elderly gentleman who had chronic abdominal pain, worse after meals. CT angiography, performed on a 64-slice CT scanner, revealed SMA dissection with a thrombus. A large artery of Drummond was also seen. The patient was managed conservatively.

  16. The oft-neglected role of parietal EEG asymmetry and risk for major depressive disorder.

    Science.gov (United States)

    Stewart, Jennifer L; Towers, David N; Coan, James A; Allen, John J B

    2011-01-01

    Relatively less right parietal activity may reflect reduced arousal and signify risk for major depressive disorder (MDD). Inconsistent findings with parietal electroencephalographic (EEG) asymmetry, however, suggest issues such as anxiety comorbidity and sex differences have yet to be resolved. Resting parietal EEG asymmetry was assessed in 306 individuals (31% male) with (n=143) and without (n=163) a DSM-IV diagnosis of lifetime MDD and no comorbid anxiety disorders. Past MDD+ women displayed relatively less right parietal activity than current MDD+ and MDD- women, replicating prior work. Recent caffeine intake, an index of arousal, moderated the relationship between depression and EEG asymmetry for women and men. Findings suggest that sex differences and arousal should be examined in studies of depression and regional brain activity.

  17. Age-related changes in parietal lobe activation during an episodic memory retrieval task.

    Science.gov (United States)

    Oedekoven, Christiane S H; Jansen, Andreas; Kircher, Tilo T; Leube, Dirk T

    2013-05-01

    The crucial role of lateral parietal regions in episodic memory has been confirmed in previous studies. While aging has an influence on retrieval of episodic memory, it remains to be examined how the involvement of lateral parietal regions in episodic memory changes with age. We investigated episodic memory retrieval in two age groups, using faces as stimuli and retrieval success as a measure of episodic memory. Young and elderly participants showed activation within a similar network, including lateral and medial parietal as well as prefrontal regions, but elderly showed a higher level of brain activation regardless of condition. Furthermore, we examined functional connectivity in the two age groups and found a more extensive network in the young group, including correlations of parietal and prefrontal regions. In the elderly, the overall stronger activation related to memory performance may indicate a compensatory process for a less extensive functional network.

  18. Fusion and Fission of Cognitive Functions in the Human Parietal Cortex

    Science.gov (United States)

    Humphreys, Gina F.; Lambon Ralph, Matthew A.

    2015-01-01

    How is higher cognitive function organized in the human parietal cortex? A century of neuropsychology and 30 years of functional neuroimaging has implicated the parietal lobe in many different verbal and nonverbal cognitive domains. There is little clarity, however, on how these functions are organized, that is, where do these functions coalesce (implying a shared, underpinning neurocomputation) and where do they divide (indicating different underlying neural functions). Until now, there has been no multi-domain synthesis in order to reveal where there is fusion or fission of functions in the parietal cortex. This aim was achieved through a large-scale activation likelihood estimation (ALE) analysis of 386 studies (3952 activation peaks) covering 8 cognitive domains. A tripartite, domain-general neuroanatomical division and 5 principles of cognitive organization were established, and these are discussed with respect to a unified theory of parietal functional organization. PMID:25205661

  19. A escrita no Ensino Superior

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    Maria Conceição Pillon Christofoli

    2013-01-01

    Full Text Available http://dx.doi.org/10.5902/198464445865 O presente artigo trata de apresentar resultados oriundos de pesquisa realizada no Ensino Superior, enfocando a escrita em contextos universitários. Depoimentos por parte dos acadêmicos evidenciam certa resistência ao ato de escrever, o que acaba muitas vezes distanciando o sujeito da produção de um texto. Assim sendo, mesmo que parciais, os resultados até então analisados dão conta de que: pressuposto 1 – há ruptura da ideia de coerência entre o que pensamos, o que conseguimos escrever, o que entende nosso interlocutor; pressuposto 2 – a autocorreção de textos como exercício de pesquisa é imprescindível para a qualificação da escrita; pressuposto 3 – os diários de aula representam rico instrumento para a qualificação da escrita no Ensino Superior; pressuposto 4 – há necessidade de que o aluno do Ensino Superior escreva variados tipos de escrita, ainda que a universidade cumpra com seu papel, enfatizando a escrita acadêmica; pressuposto 5 – o trabalho com a escrita no Ensino Superior deve enfatizar os componentes básicos da expressão escrita: o código escrito e a composição da escrita. Palavras-chave: Escrita; Ensino Superior; formação de professores.

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

    Directory of Open Access Journals (Sweden)

    Rita Moretti

    2016-12-01

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

  1. Torsion of a lipoma of parietal peritoneum: a rare case mimicking acute appendicitis.

    Science.gov (United States)

    Shrestha, Binod Bade; Karmacharya, Mikesh

    2014-06-18

    Lipomas are found most often on the torso, neck, upper thighs, upper arms and armpits; they can also occur almost anywhere in the body. Parietal peritoneum lipoma is a rare intraoperative finding during abdominal surgery. We present a case of a torted, pedunculated parietal wall lipoma in the right iliac fossa that gave rise to a clinical diagnosis of appendicitis. So far only one case has been reported.

  2. Torsion of a lipoma of parietal peritoneum: a rare case mimicking acute appendicitis

    OpenAIRE

    2014-01-01

    Lipomas are found most often on the torso, neck, upper thighs, upper arms and armpits; they can also occur almost anywhere in the body. Parietal peritoneum lipoma is a rare intraoperative finding during abdominal surgery. We present a case of a torted, pedunculated parietal wall lipoma in the right iliac fossa that gave rise to a clinical diagnosis of appendicitis. So far only one case has been reported.

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

    Science.gov (United States)

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

    2015-09-01

    The functional complexity of the parietal lobe still represents a challenge for neurophysiological and functional neuroimaging studies. While the somatosensory functions of the anterior parietal cortex are well established, the posterior parietal cortex has a relevant role in processing the sensory information, including visuo-spatial perception, visual attention, visuo-motor transformations and other complex and not completely understood functions. We retrospectively analysed all the clinical manifestations induced by intracerebral bipolar electrical stimulation in 172 patients suffering from drug-resistant focal epilepsy (mean age 25.6, standard deviation 11.6; 44% females and 56% males) with at least one electrode stereotactically implanted in the parietal cortex. A total of 1186 electrical stimulations were included in the analysis, of which 88 were subsequently excluded because of eliciting pathological electric activity or inducing ictal symptomatology. In the dominant parietal lobe, clinical responses were observed for 56 (25%) of the low-frequency stimulations and for 76 (50%) of the high-frequency stimulations. In the non-dominant parietal lobe, 111 (27%) low-frequency and 176 (55%) high-frequency stimulations were associated with a clinical response. Body scheme alteration was the only clinical effect showing a lateralization, as they were evoked only in the non-dominant hemisphere. The occurrence of somatosensory sensations, motor symptoms, dysarthria and multimodal responses were significantly associated with stimulation of the postcentral gyrus (odds ratio: 5.83, P parietal cortex with the aim to evaluate the neurophysiology of this relevant brain region. Our analysis offers a general overview of the multiple roles of the parietal cortex and supports its crucial involvement in different networks related to complex integrative functions.media-1vid110.1093/brain/awv187_video_abstractawv187_video_abstract. © The Author (2015). Published by Oxford

  4. Parietal lobe critically supports successful paired immediate and single-item delayed memory for targets.

    Science.gov (United States)

    Krumm, Sabine; Kivisaari, Sasa L; Monsch, Andreas U; Reinhardt, Julia; Ulmer, Stephan; Stippich, Christoph; Kressig, Reto W; Taylor, Kirsten I

    2017-05-01

    The parietal lobe is important for successful recognition memory, but its role is not yet fully understood. We investigated the parietal lobes' contribution to immediate paired-associate memory and delayed item-recognition memory separately for hits (targets) and correct rejections (distractors). We compared the behavioral performance of 56 patients with known parietal and medial temporal lobe dysfunction (i.e. early Alzheimer's Disease) to 56 healthy control participants in an immediate paired and delayed single item object memory task. Additionally, we performed voxel-based morphometry analyses to investigate the functional-neuroanatomic relationships between performance and voxel-based estimates of atrophy in whole-brain analyses. Behaviorally, all participants performed better identifying targets than rejecting distractors. The voxel-based morphometry analyses associated atrophy in the right ventral parietal cortex with fewer correct responses to familiar items (i.e. hits) in the immediate and delayed conditions. Additionally, medial temporal lobe integrity correlated with better performance in rejecting distractors, but not in identifying targets, in the immediate paired-associate task. Our findings suggest that the parietal lobe critically supports successful immediate and delayed target recognition memory, and that the ventral aspect of the parietal cortex and the medial temporal lobe may have complementary preferences for identifying targets and rejecting distractors, respectively, during recognition memory. Copyright © 2017. Published by Elsevier Inc.

  5. Visuo-spatial construction in patients with frontal and parietal lobe lesions

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    Himani Kashyap

    2011-04-01

    Full Text Available Visuospatial construction, traditionally viewed as a putative parietal function, also requires sustained attention, planning, organization strategies and error correction, and hence frontal lobe mediation. The relative contributions of the frontal and parietal lobes are poorly understood. To examine the contributions of parietal, frontal lobes, as well as right and left cerebral hemispheres to visuospatial construction. The Stick Construction Test for two-dimensional construction and the Block Construction Test for three-dimensional construction were administered pre-surgically to patients with lesions in the parietal lobe (n =9 and the frontal lobe (n=11, along with normal control subjects (n =20 matched to the patients on age (+/- 3 years, gender, education (+/- 3 years and handedness. The patients were significantly slower than the controls on both two-dimensional and three-dimensional tests. Patients with parietal lesions were slower than those with frontal lesions on the test of three-dimensional construction. Within each lobe patients with right and left sided lesions did not differ significantly. It appears that tests of three-dimensional construction might be most sensitive to visuospatial construction deficits. Visuospatial construction involves the mediation of both frontal and parietal lobes. The function does not appear to be lateralized. The networks arising from the parieto-occipital areas and projecting to the frontal cortices (e.g., occipito-frontal fasciculus may be the basis of the mediation of both lobes in visuospatial construction. The present findings need replication from studies with larger sample sizes.

  6. Language outcomes after resection of dominant inferior parietal lobule gliomas.

    Science.gov (United States)

    Southwell, Derek G; Riva, Marco; Jordan, Kesshi; Caverzasi, Eduardo; Li, Jing; Perry, David W; Henry, Roland G; Berger, Mitchel S

    2017-01-06

    OBJECTIVE The dominant inferior parietal lobule (IPL) contains cortical and subcortical regions essential for language. Although resection of IPL tumors could result in language deficits, little is known about the likelihood of postoperative language morbidity or the risk factors predisposing to this outcome. METHODS The authors retrospectively examined a series of patients who underwent resections of gliomas from the dominant IPL. Postoperative language outcomes were characterized across the patient population. To identify factors associated with postoperative language morbidity, the authors then compared features between those patients who experienced postoperative deficits and those who experienced no postoperative language dysfunction. RESULTS Twenty-four patients were identified for analysis. Long-term language deficits occurred in 29.2% of patients (7 of 24): 3 of these patients had experienced preoperative language deficits, whereas new long-term language deficits occurred in 4 patients (16.7%; 4 of 24). Of those patients who exhibited preoperative language deficits, 62.5% (5 of 8) experienced long-term resolution of their language deficits with surgical treatment. All patients underwent intraoperative brain mapping by direct electrical stimulation. Awake, intraoperative cortical language mapping was performed on 17 patients (70.8%). Positive cortical language sites were identified in 23.5% of these patients (4 of 17). Awake, intraoperative subcortical language mapping was performed in 8 patients (33.3%). Positive subcortical language sites were identified in 62.5% of these patients (5 of 8). Patients with positive cortical language sites exhibited a higher rate of long-term language deficits (3 of 4, 75%), compared with those who did not (1 of 13, 7.7%; p = 0.02). Although patients with positive subcortical language sites exhibited a higher rate of long-term language deficits than those who exhibited only negative sites (40.0% vs 0.0%, respectively), this

  7. Pensamiento Superior y Desarrollo Territorial

    Directory of Open Access Journals (Sweden)

    Víctor Manuel Racancoj Alonzo

    2015-04-01

    Full Text Available Esta reflexión pretende explicar el papel, fundamental, que juega el pensamiento superior, en la formulación y la práctica de modelos de desarrollo territorial local; para que contribuyan de forma sustantiva, en la transformación de las condiciones socioeconómicas adversas que hoy viven comunidades indígenas y rurales de muchos países, como Guatemala, situación que puede resumirse en altos índices de pobreza y desnutrición. Pero, el pensamiento superior, debe ser competencia de la población con pertenencia a lo local, pues si y solo si esta condición existe, se dará validez y viabilidad al desarrollo territorial. Para alcanzar competencias de pensamiento superior, en los espacios locales, se tiene que superar obstáculos en el modelo de universidad, que hoy estamos familiarizados a ver y pensar; modelos que tienen las características de: herencia colonial, disfunción con la problemática económica, cultural, social y política de la sociedad y la negación de los saberes ancestrales.

  8. Superior sulcus tumors (Pancoast tumors).

    Science.gov (United States)

    Marulli, Giuseppe; Battistella, Lucia; Mammana, Marco; Calabrese, Francesca; Rea, Federico

    2016-06-01

    Superior Sulcus Tumors, frequently termed as Pancoast tumors, are a wide range of tumors invading the apical chest wall. Due to its localization in the apex of the lung, with the potential invasion of the lower part of the brachial plexus, first ribs, vertebrae, subclavian vessels or stellate ganglion, the superior sulcus tumors cause characteristic symptoms, like arm or shoulder pain or Horner's syndrome. The management of superior sulcus tumors has dramatically evolved over the past 50 years. Originally deemed universally fatal, in 1956, Shaw and Paulson introduced a new treatment paradigm with combined radiotherapy and surgery ensuring 5-year survival of approximately 30%. During the 1990s, following the need to improve systemic as well as local control, a trimodality approach including induction concurrent chemoradiotherapy followed by surgical resection was introduced, reaching 5-year survival rates up to 44% and becoming the standard of care. Many efforts have been persecuted, also, to obtain higher complete resection rates using appropriate surgical approaches and involving multidisciplinary team including spine surgeon or vascular surgeon. Other potential treatment options are under consideration like prophylactic cranial irradiation or the addition of other chemotherapy agents or biologic agents to the trimodality approach.

  9. Vulnerability of the medial frontal corticospinal projection accompanies combined lateral frontal and parietal cortex injury in rhesus monkey.

    Science.gov (United States)

    Morecraft, R J; Ge, J; Stilwell-Morecraft, K S; McNeal, D W; Hynes, S M; Pizzimenti, M A; Rotella, D L; Darling, W G

    2015-03-01

    Concurrent damage to the lateral frontal and parietal cortex is common following middle cerebral artery infarction, leading to upper extremity paresis, paresthesia, and sensory loss. Motor recovery is often poor, and the mechanisms that support or impede this process are unclear. Since the medial wall of the cerebral hemisphere is commonly spared following stroke, we investigated the spontaneous long-term (6 and 12 month) effects of lateral frontoparietal injury (F2P2 lesion) on the terminal distribution of the corticospinal projection (CSP) from intact, ipsilesional supplementary motor cortex (M2) at spinal levels C5 to T1. Isolated injury to the frontoparietal arm/hand region resulted in a significant loss of contralateral corticospinal boutons from M2 compared with controls. Specifically, reductions occurred in the medial and lateral parts of lamina VII and the dorsal quadrants of lamina IX. There were no statistical differences in the ipsilateral CSP. Contrary to isolated lateral frontal motor injury (F2 lesion), which results in substantial increases in contralateral M2 labeling in laminae VII and IX (McNeal et al. [2010] J. Comp. Neurol. 518:586-621), the added effect of adjacent parietal cortex injury to the frontal motor lesion (F2P2 lesion) not only impedes a favorable compensatory neuroplastic response but results in a substantial loss of M2 CSP terminals. This dramatic reversal of the CSP response suggests a critical trophic role for cortical somatosensory influence on spared ipsilesional frontal corticospinal projections, and that restoration of a favorable compensatory response will require therapeutic intervention. © 2014 Wiley Periodicals, Inc.

  10. Cognitive patterns of normal elderly subjects are consistent with frontal cortico-subcortical and fronto-parietal neuropsychological models of brain aging.

    Science.gov (United States)

    Gawron, Natalia; Łojek, Emilia; Kijanowska-Haładyna, Beata; Nestorowicz, Jakub; Harasim, Andrzej; Pluta, Agnieszka; Sobańska, Marta

    2014-01-01

    Three neuropsychological theories have been developed according to a possible existence of a similar pattern of cognitive decline in elderly individuals and patients with brain damage. The respective neuropsychological theories attribute age-related deficits to: (a) dysfunction of the frontal lobes, (b) temporo-parietal dysfunction, or (c) decline of right-hemisphere functions. In the present study, we examined which of these theories best explains the cognitive patterns of normal elderly subjects older than 80 years of age (old elderly). Thirty normal old elderly subjects, 14 patients with subcortical vascular dementia, 14 with mild Alzheimer's disease, 15 with damage of the right hemisphere of the brain, and 20 young elderly controls participated. A test battery covering the main cognitive domains was administered to all participants. A hierarchical cluster analysis revealed five groups of individuals with different cognitive patterns across the whole sample. Old elderly subjects were assigned to four groups according to: (a) preserved overall cognitive performance, (b) processing speed decline, (c) attention decline, or (d) executive impairment. The results of the study are most congruent with models emphasizing frontal-lobe cortical-subcortical and fronto-parietal changes in old age. The results also indicate considerable heterogeneity in the cognitive patterns of normal old elderly adults.

  11. Superior calcium homeostasis of extraocular muscles.

    Science.gov (United States)

    Zeiger, Ulrike; Mitchell, Claire H; Khurana, Tejvir S

    2010-11-01

    Extraocular muscles (EOMs) are a unique group of skeletal muscles with unusual physiological properties such as being able to undergo rapid twitch contractions over extended periods and escape damage in the presence of excess intracellular calcium (Ca(2+)) in Duchenne's muscular dystrophy (DMD). Enhanced Ca(2+) buffering has been proposed as a contributory mechanism to explain these properties; however, the mechanisms are not well understood. We investigated mechanisms modulating Ca(2+) levels in EOM and tibialis anterior (TA) limb muscles. Using Fura-2 based ratiometric Ca(2+) imaging of primary myotubes we found that EOM myotubes reduced elevated Ca(2+) ˜2-fold faster than TA myotubes, demonstrating more efficient Ca(2+) buffering. Quantitative PCR (qPCR) and western blotting revealed higher expression of key components of the Ca(2+) regulation system in EOM, such as the cardiac/slow isoforms sarcoplasmic Ca(2+)-ATPase 2 (Serca2) and calsequestrin 2 (Casq2). Interestingly EOM expressed monomeric rather than multimeric forms of phospholamban (Pln), which was phosphorylated at threonine 17 (Thr17) but not at the serine 16 (Ser16) residue. EOM Pln remained monomeric and unphosphorylated at Ser16 despite protein kinase A (PKA) treatment, suggesting differential signalling and modulation cascades involving Pln-mediated Ca(2+) regulation in EOM. Increased expression of Ca(2+)/SR mRNA, proteins, differential post-translational modification of Pln and superior Ca(2+) buffering is consistent with the improved ability of EOM to handle elevated intracellular Ca(2+) levels. These characteristics provide mechanistic insight for the potential role of superior Ca(2+) buffering in the unusual physiology of EOM and their sparing in DMD.

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

    Science.gov (United States)

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

    2015-02-01

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

  13. Radiation damage

    CERN Document Server

    Heijne, Erik H M; CERN. Geneva

    1998-01-01

    a) Radiation damage in organic materials. This series of lectures will give an overview of radiation effects on materials and components frequently used in accelerator engineering and experiments. Basic degradation phenomena will be presented for organic materials with comprehensive damage threshold doses for commonly used rubbers, thermoplastics, thermosets and composite materials. Some indications will be given for glass, scintillators and optical fibres. b) Radiation effects in semiconductor materials and devices. The major part of the time will be devoted to treat radiation effects in semiconductor sensors and the associated electronics, in particular displacement damage, interface and single event phenomena. Evaluation methods and practical aspects will be shown. Strategies will be developed for the survival of the materials under the expected environmental conditions of the LHC machine and detectors. I will describe profound revolution in our understanding of black holes and their relation to quantum me...

  14. Entidades fiscalizadoras superiores y accountability

    OpenAIRE

    Estela Moreno, María

    2016-01-01

    OBJETIVOS DE LA TESIS: El objetivo general del trabajo es establecer el nivel de eficacia de las Entidades Fiscalizadoras Superiores (EFS) como agencia asignada y herramienta de accountability horizontal, a través de la valoración de su diseño institucional y de la calidad de sus productos finales, los informes de auditoría, estableciéndose los siguientes objetivos específicos: 1. Relevar las nociones de accountability, actualizando el Estado del Arte de la cuestión. 2. Analizar la ...

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

    Science.gov (United States)

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

    2014-06-01

    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 0-130 ms after the onset of the stimulus 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.

  16. Estimating frontal and parietal involvement in cognitive estimation: a study of focal neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Teagan Ann Bisbing

    2015-06-01

    Full Text Available We often estimate an unknown value based on available relevant information, a process known as cognitive estimation. In this study, we assess the cognitive and neuroanatomic basis for quantitative estimation by examining deficits in patients with focal neurodegenerative disease in frontal and parietal cortex. Executive function and number knowledge are key components in cognitive estimation. Prefrontal cortex has been implicated in multilevel reasoning and planning processes, and parietal cortex has been associated with number knowledge required for such estimations. We administered the Biber Cognitive Estimation Test (BCET to assess cognitive estimation in 22 patients with prefrontal disease due to behavioral variant frontotemporal dementia (bvFTD, to 17 patients with parietal disease due to corticobasal syndrome (CBS or posterior cortical atrophy (PCA and 11 patients with mild cognitive impairment (MCI. Both bvFTD and CBS/PCA patients had significantly more difficulty with cognitive estimation than controls. MCI were not impaired on BCET relative to controls. Regression analyses related BCET performance to gray matter atrophy in right lateral prefrontal and orbital frontal cortices in bvFTD, and to atrophy in right inferior parietal cortex, right insula and fusiform cortices in CBS/PCA. These results are consistent with the hypothesis that a frontal-parietal network plays a crucial role in cognitive estimation.

  17. Early math achievement and functional connectivity in the fronto-parietal network.

    Science.gov (United States)

    Emerson, Robert W; Cantlon, Jessica F

    2012-02-15

    In this study we test the hypothesis that the functional connectivity of the frontal and parietal regions that children recruit during a basic numerical task (matching Arabic numerals to arrays of dots) is predictive of their math test scores (TEMA-3; Ginsburg, 2003). Specifically, we tested 4-11-year-old children on a matching task during fMRI to localize a fronto-parietal network that responds more strongly during numerical matching than matching faces, words, or shapes. We then tested the functional connectivity between those regions during an independent task: natural viewing of an educational video that included math topics. Using this novel natural viewing method, we found that the connectivity between frontal and parietal regions during task-independent free-viewing of educational material is correlated with children's basic number matching ability, as well as their scores on the standardized test of mathematical ability (the TEMA). The correlation between children's mathematics scores and fronto-parietal connectivity is math-specific in the sense that it is independent of children's verbal IQ scores. Moreover, a control network, selective for faces, showed no correlation with mathematics performance. Finally, brain regions that correlate with subjects' overall response times in the matching task do not account for our number- and math-related effects. We suggest that the functional intersection of number-related frontal and parietal regions is math-specific. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Dynamic social adaptation of motion-related neurons in primate parietal cortex.

    Directory of Open Access Journals (Sweden)

    Naotaka Fujii

    Full Text Available Social brain function, which allows us to adapt our behavior to social context, is poorly understood at the single-cell level due largely to technical limitations. But the questions involved are vital: How do neurons recognize and modulate their activity in response to social context? To probe the mechanisms involved, we developed a novel recording technique, called multi-dimensional recording, and applied it simultaneously in the left parietal cortices of two monkeys while they shared a common social space. When the monkeys sat near each other but did not interact, each monkey's parietal activity showed robust response preference to action by his own right arm and almost no response to action by the other's arm. But the preference was broken if social conflict emerged between the monkeys-specifically, if both were able to reach for the same food item placed on the table between them. Under these circumstances, parietal neurons started to show complex combinatorial responses to motion of self and other. Parietal cortex adapted its response properties in the social context by discarding and recruiting different neural populations. Our results suggest that parietal neurons can recognize social events in the environment linked with current social context and form part of a larger social brain network.

  19. Estimating frontal and parietal involvement in cognitive estimation: a study of focal neurodegenerative diseases

    Science.gov (United States)

    Bisbing, Teagan A.; Olm, Christopher A.; McMillan, Corey T.; Rascovsky, Katya; Baehr, Laura; Ternes, Kylie; Irwin, David J.; Clark, Robin; Grossman, Murray

    2015-01-01

    We often estimate an unknown value based on available relevant information, a process known as cognitive estimation. In this study, we assess the cognitive and neuroanatomic basis for quantitative estimation by examining deficits in patients with focal neurodegenerative disease in frontal and parietal cortex. Executive function and number knowledge are key components in cognitive estimation. Prefrontal cortex has been implicated in multilevel reasoning and planning processes, and parietal cortex has been associated with number knowledge required for such estimations. We administered the Biber cognitive estimation test (BCET) to assess cognitive estimation in 22 patients with prefrontal disease due to behavioral variant frontotemporal dementia (bvFTD), to 17 patients with parietal disease due to corticobasal syndrome (CBS) or posterior cortical atrophy (PCA) and 11 patients with mild cognitive impairment (MCI). Both bvFTD and CBS/PCA patients had significantly more difficulty with cognitive estimation than controls. MCI were not impaired on BCET relative to controls. Regression analyses related BCET performance to gray matter atrophy in right lateral prefrontal and orbital frontal cortices in bvFTD, and to atrophy in right inferior parietal cortex, right insula, and fusiform cortices in CBS/PCA. These results are consistent with the hypothesis that a frontal-parietal network plays a crucial role in cognitive estimation. PMID:26089786

  20. Drug-resistant parietal lobe epilepsy: clinical manifestations and surgery outcome.

    Science.gov (United States)

    Asadollahi, Marjan; Sperling, Michael R; Rabiei, Amin H; Asadi-Pooya, Ali A

    2017-03-01

    We reviewed a large surgical cohort to investigate the clinical manifestations, EEG and neuroimaging findings, and postoperative seizure outcome in patients with drug-resistant parietal lobe epilepsy (PLE). All drug-resistant PLE patients, who were investigated for epilepsy surgery at Jefferson Comprehensive Epilepsy Center between 1986 and 2015, were identified. Demographic data, seizure data, EEG recordings, brain MRI, pathological findings, and postsurgical seizure outcome were reviewed. In total, 18 patients (11 males and seven females) were identified. Sixteen patients (88%) had tonic-clonic seizures, 12 (66%) had focal seizures with impaired awareness, and 13 (72%) described auras. Among 15 patients who had brain MRI, 14 patients (93%) had parietal lobe lesions. Only three of 15 patients (20%) who had interictal scalp EEG recordings showed parietal interictal spikes. Of 12 patients with available ictal surface EEG recordings, only three patients (25%) had parietal ictal EEG onset. After a mean follow-up duration of 8.6 years, 14 patients (77.7%) showed a favourable postoperative seizure outcome. In patients with PLE, semiology and EEG may be misleading and brain MRI is the most valuable tool to localize the epileptogenic zone. Postsurgical seizure outcome was favourable in our patients with drug-resistant parietal lobe epilepsy.

  1. Laminar thickness alterations in the fronto-parietal cortical mantle of patients with attention-deficit/hyperactivity disorder.

    Directory of Open Access Journals (Sweden)

    Elseline Hoekzema

    Full Text Available Although Attention-Deficit/Hyperactivity Disorder (ADHD was initially regarded as a disorder exclusive to childhood, nowadays its prevalence in adulthood is well established. The development of novel techniques for quantifying the thickness of the cerebral mantle allows the further exploration of the neuroanatomical profiles underlying the child and adult form of the disorder. To examine the cortical mantle in children and adults with ADHD, we applied a vertex-wise analysis of cortical thickness to anatomical brain MRI scans acquired from children with (n = 43 and without ADHD (n = 41, as well as a group of adult neurotypical individuals (n = 31, adult patients with a history of stimulant treatment (n = 31 and medication-naïve adults with ADHD (n = 24. We observed several clusters of reduced laminar cortical thickness in ADHD patients in comparison to neurotypical individuals. These differences were primarily located in the dorsal attention network, including the bilateral inferior and superior parietal cortex and a section of the frontal cortex (centered on the superior frontal and precentral gyrus bilaterally. Further laminar thickness deficits were observed in the bilateral orbitofrontal cortex and medial occipital cortex. The deficits in the cortical surface were especially pronounced in the child sample, while adult patients showed a more typical laminar thickness across the cerebral mantle. These findings show that the neuroanatomical profile of ADHD, especially the childhood form of the disorder, involves robust alterations in the cortical mantle, which are most prominent in brain regions subserving attentional processing.

  2. Laminar Thickness Alterations in the Fronto-Parietal Cortical Mantle of Patients with Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Ramos-Quiroga, J. Antoni; Fernández, Vanesa Richarte; Picado, Marisol; Bosch, Rosa; Soliva, Juan Carlos; Rovira, Mariana; Vives, Yolanda; Bulbena, Antonio; Tobeña, Adolf; Casas, Miguel; Vilarroya, Oscar

    2012-01-01

    Although Attention-Deficit/Hyperactivity Disorder (ADHD) was initially regarded as a disorder exclusive to childhood, nowadays its prevalence in adulthood is well established. The development of novel techniques for quantifying the thickness of the cerebral mantle allows the further exploration of the neuroanatomical profiles underlying the child and adult form of the disorder. To examine the cortical mantle in children and adults with ADHD, we applied a vertex-wise analysis of cortical thickness to anatomical brain MRI scans acquired from children with (n = 43) and without ADHD (n = 41), as well as a group of adult neurotypical individuals (n = 31), adult patients with a history of stimulant treatment (n = 31) and medication-naïve adults with ADHD (n = 24). We observed several clusters of reduced laminar cortical thickness in ADHD patients in comparison to neurotypical individuals. These differences were primarily located in the dorsal attention network, including the bilateral inferior and superior parietal cortex and a section of the frontal cortex (centered on the superior frontal and precentral gyrus bilaterally). Further laminar thickness deficits were observed in the bilateral orbitofrontal cortex and medial occipital cortex. The deficits in the cortical surface were especially pronounced in the child sample, while adult patients showed a more typical laminar thickness across the cerebral mantle. These findings show that the neuroanatomical profile of ADHD, especially the childhood form of the disorder, involves robust alterations in the cortical mantle, which are most prominent in brain regions subserving attentional processing. PMID:23239964

  3. Differential parietal and temporal contributions to music perception in improvising and score-dependent musicians, an fMRI study.

    Science.gov (United States)

    Harris, Robert; de Jong, Bauke M

    2015-10-22

    Using fMRI, cerebral activations were studied in 24 classically-trained keyboard performers and 12 musically unskilled control subjects. Two groups of musicians were recruited: improvising (n=12) and score-dependent (non-improvising) musicians (n=12). While listening to both familiar and unfamiliar music, subjects either (covertly) appraised the presented music performance or imagined they were playing the music themselves. We hypothesized that improvising musicians would exhibit enhanced efficiency of audiomotor transformation reflected by stronger ventral premotor activation. Statistical Parametric Mapping revealed that, while virtually 'playing along׳ with the music, improvising musicians exhibited activation of a right-hemisphere distribution of cerebral areas including posterior-superior parietal and dorsal premotor cortex. Involvement of these right-hemisphere dorsal stream areas suggests that improvising musicians recruited an amodal spatial processing system subserving pitch-to-space transformations to facilitate their virtual motor performance. Score-dependent musicians recruited a primarily left-hemisphere pattern of motor areas together with the posterior part of the right superior temporal sulcus, suggesting a relationship between aural discrimination and symbolic representation. Activations in bilateral auditory cortex were significantly larger for improvising musicians than for score-dependent musicians, suggesting enhanced top-down effects on aural perception. Our results suggest that learning to play a music instrument primarily from notation predisposes musicians toward aural identification and discrimination, while learning by improvisation involves audio-spatial-motor transformations, not only during performance, but also perception. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Cognitive signals for brain-machine interfaces in posterior parietal cortex include continuous 3D trajectory commands.

    Science.gov (United States)

    Hauschild, Markus; Mulliken, Grant H; Fineman, Igor; Loeb, Gerald E; Andersen, Richard A

    2012-10-16

    Cortical neural prosthetics extract command signals from the brain with the goal to restore function in paralyzed or amputated patients. Continuous control signals can be extracted from the motor cortical areas, whereas neural activity from posterior parietal cortex (PPC) can be used to decode cognitive variables related to the goals of movement. Because typical activities of daily living comprise both continuous control tasks such as reaching, and tasks benefiting from discrete control such as typing on a keyboard, availability of both signals simultaneously would promise significant increases in performance and versatility. Here, we show that PPC can provide 3D hand trajectory information under natural conditions that would be encountered for prosthetic applications, thus allowing simultaneous extraction of continuous and discrete signals without requiring multisite surgical implants. We found that limb movements can be decoded robustly and with high accuracy from a small population of neural units under free gaze in a complex 3D point-to-point reaching task. Both animals' brain-control performance improved rapidly with practice, resulting in faster target acquisition and increasing accuracy. These findings disprove the notion that the motor cortical areas are the only candidate areas for continuous prosthetic command signals and, rather, suggests that PPC can provide equally useful trajectory signals in addition to discrete, cognitive variables. Hybrid use of continuous and discrete signals from PPC may enable a new generation of neural prostheses providing superior performance and additional flexibility in addressing individual patient needs.

  5. Mathematically gifted adolescents use more extensive and more bilateral areas of the fronto-parietal network than controls during executive functioning and fluid reasoning tasks.

    Science.gov (United States)

    Desco, Manuel; Navas-Sanchez, Francisco J; Sanchez-González, Javier; Reig, Santiago; Robles, Olalla; Franco, Carolina; Guzmán-De-Villoria, Juan A; García-Barreno, Pedro; Arango, Celso

    2011-07-01

    The main goal of this study was to investigate the neural substrates of fluid reasoning and visuospatial working memory in adolescents with precocious mathematical ability. The study population comprised two groups of adolescents: 13 math-gifted adolescents and 14 controls with average mathematical skills. Patterns of activation specific to reasoning tasks in math-gifted subjects were examined using functional magnetic resonance images acquired while the subjects were performing Raven's Advanced Progressive Matrices (RAPM) and the Tower of London (TOL) tasks. During the tasks, both groups showed significant activations in the frontoparietal network. In the math-gifted group, clusters of activation were always bilateral and more regions were recruited, especially in the right hemisphere. In the TOL task, math-gifted adolescents showed significant hyper-activations relative to controls in the precuneus, superior occipital lobe (BA 19), and medial temporal lobe (BA 39). The maximum differences between the groups were detected during RAPM tasks at the highest level of difficulty, where math-gifted subjects showed significant activations relative to controls in the right inferior parietal lobule (BA 40), anterior cingulated gyrus (BA 32), and frontal (BA 9, and BA 6) areas. Our results support the hypothesis that greater ability for complex mathematical reasoning may be related to more bilateral patterns of activation and that increased activation in the parietal and frontal regions of math-gifted adolescents is associated with enhanced skills in visuospatial processing and logical reasoning.

  6. The sentence superiority effect revisited.

    Science.gov (United States)

    Snell, Joshua; Grainger, Jonathan

    2017-11-01

    A sentence superiority effect was investigated using post-cued word-in-sequence identification with the rapid parallel visual presentation (RPVP) of four horizontally aligned words. The four words were presented for 200ms followed by a post-mask and cue for partial report. They could form a grammatically correct sentence or were formed of the same words in a scrambled agrammatical sequence. Word identification was higher in the syntactically correct sequences, and crucially, this sentence superiority effect did not vary as a function of the target's position in the sequence. Cloze probability measures for words at the final, arguably most predictable position, revealed overall low values that did not interact with the effects of sentence context, suggesting that these effects were not driven by word predictability. The results point to a level of parallel processing across multiple words that enables rapid extraction of their syntactic categories. These generate a sentence-level representation that constrains the recognition process for individual words, thus facilitating parallel word processing when the sequence is grammatically sound. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Tort Damages

    NARCIS (Netherlands)

    L.T. Visscher (Louis)

    2008-01-01

    textabstractAbstract: In this Chapter, I provide an overview of Law and Economics literature regarding tort damages. Where necessary, attention is also spent to rules of tort liability. Both types of rules provide behavioral incentives to both injurers and victims, with respect to their level of

  8. Tort Damages

    NARCIS (Netherlands)

    L.T. Visscher (Louis)

    2008-01-01

    textabstractAbstract: In this Chapter, I provide an overview of Law and Economics literature regarding tort damages. Where necessary, attention is also spent to rules of tort liability. Both types of rules provide behavioral incentives to both injurers and victims, with respect to their level of car

  9. Head position signals used by parietal neurons to encode locations of visual stimuli.

    Science.gov (United States)

    Brotchie, P R; Andersen, R A; Snyder, L H; Goodman, S J

    1995-05-18

    The mechanism for object location in the environment, and the perception of the external world as stable when eyes, head and body are moved, have long been thought to be centred on the posterior parietal cortex. However, head position signals, and their integration with visual and eye position signals to form a representation of space referenced to the body, have never been examined in any area of the cortex. Here we show that the visual and saccadic activities of parietal neurons are strongly affected by head position. The eye and head position effects are equivalent for individual neurons, indicating that the modulation is a function of gaze direction, regardless of whether the eyes or head are used to direct gaze. These data are consistent with the idea that the posterior parietal cortex contains a distributed representation of space in body-centred coordinates.

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

    Science.gov (United States)

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

    2016-01-01

    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. PMID:27529410

  11. Preparative activities in posterior parietal cortex for self-paced movement in monkeys.

    Science.gov (United States)

    Gemba, Hisae; Matsuura-Nakao, Kazuko; Matsuzaki, Ryuichi

    2004-02-26

    Cortical field potentials were recorded by electrodes implanted chronically on the surface and at a 2.0-3.0 mm depth in various cortices in monkeys performing self-paced finger, toe, mouth, hand or trunk movements. Surface-negative, depth-positive potentials (readiness potential) appeared in the posterior parietal cortex about 1.0 s before onset of every self-paced movement, as well as in the premotor, motor and somatosensory cortices. Somatotopical distribution was seen in the readiness potential in the posterior parietal cortex, although it was not so distinct as that in the motor or somatosensory cortex. This suggests that the posterior parietal cortex is involved in preparation for self-paced movement of any body part. This study contributes to the investigation of central nervous mechanisms of voluntary movements initiated by internal stimulus.

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

    Science.gov (United States)

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

    2016-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Li eZhang

    2014-06-01

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

  14. Dynamic changes in phase-amplitude coupling facilitate spatial attention control in fronto-parietal cortex.

    Directory of Open Access Journals (Sweden)

    Sara M Szczepanski

    2014-08-01

    Full Text Available Attention is a core cognitive mechanism that allows the brain to allocate limited resources depending on current task demands. A number of frontal and posterior parietal cortical areas, referred to collectively as the fronto-parietal attentional control network, are engaged during attentional allocation in both humans and non-human primates. Numerous studies have examined this network in the human brain using various neuroimaging and scalp electrophysiological techniques. However, little is known about how these frontal and parietal areas interact dynamically to produce behavior on a fine temporal (sub-second and spatial (sub-centimeter scale. We addressed how human fronto-parietal regions control visuospatial attention on a fine spatiotemporal scale by recording electrocorticography (ECoG signals measured directly from subdural electrode arrays that were implanted in patients undergoing intracranial monitoring for localization of epileptic foci. Subjects (n = 8 performed a spatial-cuing task, in which they allocated visuospatial attention to either the right or left visual field and detected the appearance of a target. We found increases in high gamma (HG power (70-250 Hz time-locked to trial onset that remained elevated throughout the attentional allocation period over frontal, parietal, and visual areas. These HG power increases were modulated by the phase of the ongoing delta/theta (2-5 Hz oscillation during attentional allocation. Critically, we found that the strength of this delta/theta phase-HG amplitude coupling predicted reaction times to detected targets on a trial-by-trial basis. These results highlight the role of delta/theta phase-HG amplitude coupling as a mechanism for sub-second facilitation and coordination within human fronto-parietal cortex that is guided by momentary attentional demands.

  15. Frontal and Parietal Cortices Show Different Spatiotemporal Dynamics across Problem-solving Stages.

    Science.gov (United States)

    Tschentscher, Nadja; Hauk, Olaf

    2016-08-01

    Arithmetic problem-solving can be conceptualized as a multistage process ranging from task encoding over rule and strategy selection to step-wise task execution. Previous fMRI research suggested a frontal-parietal network involved in the execution of complex numerical and nonnumerical tasks, but evidence is lacking on the particular contributions of frontal and parietal cortices across time. In an arithmetic task paradigm, we evaluated individual participants' "retrieval" and "multistep procedural" strategies on a trial-by-trial basis and contrasted those in time-resolved analyses using combined EEG and MEG. Retrieval strategies relied on direct retrieval of arithmetic facts (e.g., 2 + 3 = 5). Procedural strategies required multiple solution steps (e.g., 12 + 23 = 12 + 20 + 3 or 23 + 10 + 2). Evoked source analyses revealed independent activation dynamics within the first second of problem-solving in brain areas previously described as one network, such as the frontal-parietal cognitive control network: The right frontal cortex showed earliest effects of strategy selection for multistep procedural strategies around 300 msec, before parietal cortex activated around 700 msec. In time-frequency source power analyses, memory retrieval and multistep procedural strategies were differentially reflected in theta, alpha, and beta frequencies: Stronger beta and alpha desynchronizations emerged for procedural strategies in right frontal, parietal, and temporal regions as function of executive demands. Arithmetic fact retrieval was reflected in right prefrontal increases in theta power. Our results demonstrate differential brain dynamics within frontal-parietal networks across the time course of a problem-solving process, and analyses of different frequency bands allowed us to disentangle cortical regions supporting the underlying memory and executive functions.

  16. 78 FR 21116 - Superior Supplier Incentive Program

    Science.gov (United States)

    2013-04-09

    ... Department of the Navy Superior Supplier Incentive Program AGENCY: Department of the Navy, DoD. ACTION... policy that will establish a Superior Supplier Incentive Program (SSIP). Under the SSIP, contractors that..., performance, quality, and business relations would be granted Superior Supplier Status (SSS). Contractors...

  17. [Ictal Gerstmann's syndrome in a patient with symptomatic parietal lobe epilepsy].

    Science.gov (United States)

    Shimotake, Akihiro; Fujita, Youshi; Ikeda, Akio; Tomimoto, Hidekazu; Takahashi, Jun; Takahashi, Ryosuke

    2008-03-01

    A 34-year-old man with astrocytoma in the left parietal lobe had symptomatic partial epilepsy, and he presented transient episodes of acalculia, agraphia and finger agnosia. Occasionally he had difficulty in finding appropriate letters when making an e-mail, and difficulty in writing and calculation. Neurological examinations revealed ictal symptoms of Gerstmann's syndrome without right to left disorientation. No other higher cortical dysfunction or neurological deficits were noted. Scalp EEGs showed frequent, regional ictal discharges in the left parietal area lasting for 60-240 seconds. These clinico-electrographical observations strongly support that epileptic seizures produced a loss of cortical higher function manifesting Gerstmann's syndrome.

  18. superior en México

    Directory of Open Access Journals (Sweden)

    César Mureddu Torres

    2008-01-01

    Full Text Available El presente artículo desarrolla algunos de los retos que ha traído consigo el acceso a la información existente en la red de Internet y lo que ello supone. Se abordan principalmente las consecuencias de la presencia actual de una sociedad llamada del conocimiento, si se mantiene la confusión entre conocimiento e información. Por ello, la sola gestión de la información no puede ser tomada como definitoria respecto a la función de educación superior confiada a las universidades. Hacerlo sería cometer un error aún más grave que la confusión teórica entre los términos mencionados.

  19. Escuela Superior de Palos Verdes

    Directory of Open Access Journals (Sweden)

    Neutra, Richard J.

    1965-02-01

    Full Text Available Before initiating the building operations for the «Palos Verdes» School, the site was divided into two large horizontal surfaces, at different levels. The lower one served to accommodate the playing fields, a car park, the physical training building, and shop and ancillary buildings. On the higher of these two surfaces, and to the West of the access road, there is a car park and also the building and plot of ground devoted to agricultural technology, as well as the literary studies and general purpose buildings. As a complement to these, there is a series of blocks, arranged in parallel rows, which house the administrative offices, the art school, the craft's school, the general classrooms, and those devoted to higher education. The fascinating aspect of this school is the outstanding penetration of the architect's mind into the essential function of the project. Its most evident merit is the sense of comradeship and harmony that permeates the whole architectural manifold.Antes de construir el complejo escolar «Palos Verdes» se comenzó por crear, en el terreno, dos grandes mesetas a niveles diferentes. Sobre el inferior se organizaron: los campos de juegos, de deportes, un aparcamiento, el edificio para educación física y los destinados a tiendas y servicios. Sobre la meseta superior, al oeste de la vía de acceso, se dispuso un aparcamiento y el edificio y campo para adiestramiento agrícola; al este, otro aparcamiento, el edificio dedicado a materias literarias, y el destinado a usos múltiples. Completan las instalaciones de la escuela una serie de bloques paralelos: la administración, la escuela de arte, las clases de trabajos manuales, las aulas de enseñanzas generales, y las de los cursos superiores. Lo fascinante de este complejo escolar es la perfecta y magistral compenetración del arquitecto con el tema proyectado, y su mayor mérito, la sensación de cordialidad y armonía con el ambiente.

  20. Lipid peroxidation following superior mesenteric artery occlusion in rat intestine

    Directory of Open Access Journals (Sweden)

    P. Pasbakhsh

    2006-07-01

    Full Text Available Background: The aim of this study was to determine the level of lipid peroxidation and tissue protein after superior mesenteric artery occlusion tissue damage. The effect of melatonin as anti oxidant and free radical scavenger in prevention of tissue damage, were also evaluated. Methods: Thity six young male Wisatr-Albino rats (weight: 80-120 gr, were divided equally in 6 group with different concentrations of melatonin (10,20,30 mg/kg treatment. Group 1was control, group 2 the sham that surgical process was applied until superior mesenteric artery dissection and received vehicle solution only in equally volume by intra muscular route. Group 3 was ischemia- reperfusion (I/R, group 4 was I/R plus melatonin 10 mg/kg, group 5 I/R plus melatonin 20 mg/kg and finally group 6 I/R plus melatonin 30 mg/kg. After laparatomy, a microvascular atraumatic clip was placed across the superior mesenteric artery under general anaesthesia and itbremoved after ischemia for 30 minutes. The first dose of melatonin was applied just beforereperfusion, second dose, after reperfusion and third dose on the second day .On third day rats were killed and their bowels were removed. The level of tissue melandialdehyde (MDA as index of lipid peroxidation and tissue protein was determined. Results: The level of tissue MDA were significantly lower in group 4, 5, 6 than group 3 (p0, 05. Conclusion: These results suggest that melatonin 10 mg/kg has antioxidant effect in prevention of inducing tissue damage during SMA occlusion in rat intestine.

  1. Neglect-like visual exploration behaviour after theta burst transcranial magnetic stimulation of the right posterior parietal cortex.

    Science.gov (United States)

    Nyffeler, Thomas; Cazzoli, Dario; Wurtz, Pascal; Lüthi, Mathias; von Wartburg, Roman; Chaves, Silvia; Déruaz, Anouk; Hess, Christian W; Müri, René M

    2008-04-01

    The right posterior parietal cortex (PPC) is critically involved in visual exploration behaviour, and damage to this area may lead to neglect of the left hemispace. We investigated whether neglect-like visual exploration behaviour could be induced in healthy subjects using theta burst repetitive transcranial magnetic stimulation (rTMS). To this end, one continuous train of theta burst rTMS was applied over the right PPC in 12 healthy subjects prior to a visual exploration task where colour photographs of real-life scenes were presented on a computer screen. In a control experiment, stimulation was also applied over the vertex. Eye movements were measured, and the distribution of visual fixations in the left and right halves of the screen was analysed. In comparison to the performance of 28 control subjects without stimulation, theta burst rTMS over the right PPC, but not the vertex, significantly decreased cumulative fixation duration in the left screen-half and significantly increased cumulative fixation duration in the right screen-half for a time period of 30 min. These results suggest that theta burst rTMS is a reliable method of inducing transient neglect-like visual exploration behaviour.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Cortical infarction of the right parietal lobe and neurogenic heart disease A report of three cases

    Institute of Scientific and Technical Information of China (English)

    Fang Li; Yujie Jia

    2012-01-01

    Three male patients were diagnosed with new cortical infarctions of the right parietal lobe on the basis of head magnetic resonance imaging; high-intensity signals indicating lesions in the right parietal lobe were noted on diffusion-weighted images at admission. Two of them presented with left hand weakness, and one exhibited left upper limb weakness. Treatment for improving blood supply to the brain was administered. One patient died suddenly because of ventricular fibrillation 3 days after admission. The other two patients had increased troponin levels and abnormal elec-trocardiograms, and were diagnosed with acute myocardial infarction half a month after admission. When lesions exist in field 7 of the parietal cortex (resulting in paralysis of the contralateral hand), the sympathetic center of the posterior lateral nucleus of the hypothalamus demonstrates compensatory excitement, which easily causes tachyarrhythmia and sudden death. Our experi-mental findings indicate that close electrocardiograph monitoring and cerebral infarction treatment should be standard procedures to predict and help prevent heart disease in patients with cerebral infarction in the right parietal lobe and left upper limb weakness as the main complaint.

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

    NARCIS (Netherlands)

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

    2008-01-01

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

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

    NARCIS (Netherlands)

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

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

  6. Monitoring cerebral tissue oxygen saturation at frontal and parietal regions during carotid artery stenting.

    Science.gov (United States)

    Meng, Lingzhong; Hall, Melanie; Settecase, Fabio; Higashida, Randall T; Gelb, Adrian W

    2016-04-01

    Cerebral oximetry is normally placed on the upper forehead to monitor the frontal lobe cerebral tissue oxygen saturation (SctO2). We present a case in which the SctO2 was simultaneously monitored at both frontal and parietal regions during internal carotid artery (ICA) stenting. Our case involves a 79-year-old man who presented after a sudden fall and was later diagnosed with a watershed ischemic stroke in the distal fields perfused by the left middle cerebral artery. He had diffuse atherosclerotic occlusive lesions in the carotid and cerebral arterial systems including an 85 % stenotic lesion in the left distal cervical ICA. The brain territory perfused by the left ICA was devoid of collateral flow from anterior and posterior communicating arteries due to an abnormal circle of Willis. During stenting, the SctO2 monitored at both frontal and parietal regions tracked the procedure-induced acute flow change. However, the baseline SctO2 values of frontal and parietal regions differed. The SctO2-MAP correlation was more consistent on the stroked hemisphere than the non-stroked hemisphere. This case showed that SctO2 can be reliably monitored at the parietal region, which is primarily perfused by the ICA. SctO2 of the stroked brain is more pressure dependent than the non-stroked brain.

  7. 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

    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...

  8. Actions of parathyroid hormone related peptide in mouse parietal endoderm formation

    NARCIS (Netherlands)

    Veltmaat, J.M.

    2001-01-01

    Summary Since about a decade, several reports have strongly suggested a role for parathyroid hormone related peptide (PTHrP) in the formation of parietal endoderm (PE) in the mouse embryo. This thesis is aimed first at elucidating the biological significance of parathyroid hormone related peptide

  9. Posterior midline and ventral parietal activity is associated with retrieval success and encoding failure

    NARCIS (Netherlands)

    Daselaar, S.M.; Prince, S.E.; Dennis, N.A.; Hayes, S.M.; Kim, H.; Cabeza, R.

    2009-01-01

    The ventral part of lateral posterior parietal cortex (VPC) and the posterior midline region (PMR), including the posterior cingulate cortex and precuneus, tend to show deactivation during demanding cognitive tasks, and have been associated with the default mode of the brain. Interestingly, PMR and

  10. Children's Left Parietal Brain Activation during Mental Rotation Is Reliable as Well as Specific

    Science.gov (United States)

    Heil, Martin; Jansen-Osmann, Petra

    2007-01-01

    Some recent evidence suggests that mental rotation of characters in children aged 7 or 8 years might be lateralized to the left parietal hemisphere. An alternative statement exists, however, the finding might be completely unspecific for mental rotation but either be simply a function of task difficulty or a consequence of the use of characters as…

  11. The Neural Dynamics of Fronto-Parietal Networks in Childhood Revealed using Magnetoencephalography.

    Science.gov (United States)

    Astle, Duncan E; Luckhoo, Henry; Woolrich, Mark; Kuo, Bo-Cheng; Nobre, Anna C; Scerif, Gaia

    2015-10-01

    Our ability to hold information in mind is limited, requires a high degree of cognitive control, and is necessary for many subsequent cognitive processes. Children, in particular, are highly variable in how, trial-by-trial, they manage to recruit cognitive control in service of memory. Fronto-parietal networks, typically recruited under conditions where this cognitive control is needed, undergo protracted development. We explored, for the first time, whether dynamic changes in fronto-parietal activity could account for children's variability in tests of visual short-term memory (VSTM). We recorded oscillatory brain activity using magnetoencephalography (MEG) as 9- to 12-year-old children and adults performed a VSTM task. We combined temporal independent component analysis (ICA) with general linear modeling to test whether the strength of fronto-parietal activity correlated with VSTM performance on a trial-by-trial basis. In children, but not adults, slow frequency theta (4-7 Hz) activity within a right lateralized fronto-parietal network in anticipation of the memoranda predicted the accuracy with which those memory items were subsequently retrieved. These findings suggest that inconsistent use of anticipatory control mechanism contributes significantly to trial-to-trial variability in VSTM maintenance performance.

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2009-01-01

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

  14. Functional rather than effector-specific organization of human posterior parietal cortex

    NARCIS (Netherlands)

    Heed, T.; Beurze, S.M.; Toni, I.; Roder, B.; Medendorp, Pieter

    2011-01-01

    Neurophysiological and neuroimaging studies have shown that the posterior parietal cortex (PPC) distinguishes between the planning of eye and hand movements. This distinction has usually been interpreted as evidence for a modular, effector-specific organization of this cerebral region. However, the

  15. Task-Dependent Changes in Frontal-Parietal Activation and Connectivity During Visual Search.

    Science.gov (United States)

    Maximo, Jose O; Neupane, Ajaya; Saxena, Nitesh; Joseph, Robert M; Kana, Rajesh K

    2016-05-01

    Visual search is an important skill in navigating and locating objects (a target) among distractors in our environment. Efficient and faster target detection involves reciprocal interaction between a viewer's attentional resources as well as salient target characteristics. The neural correlates of visual search have been extensively investigated over the last decades, suggesting the involvement of a frontal-parietal network comprising the frontal eye fields (FEFs) and intraparietal sulcus (IPS). In addition, activity and connectivity of these network changes as the visual search become complex and more demanding. The current functional magnetic resonance imaging study examined the modulation of the frontal-parietal network in response to cognitive demand in 22 healthy adult participants. In addition to brain activity, changes in functional connectivity and effective connectivity in this network were examined in response to easy and difficult visual search. Results revealed significantly increased activation in FEF, IPS, and supplementary motor area, more so in difficult search than in easy search. Functional and effective connectivity analyses showed enhanced connectivity in the frontal-parietal network during difficult search and enhanced information transfer from left to right hemisphere during the difficult search process. Our overall findings suggest that cognitive demand significantly increases brain resources across all three measures of brain processing. In sum, we found that goal-directed visual search engages a network of frontal-parietal areas that are modulated in relation to cognitive demand.

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

    NARCIS (Netherlands)

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

    2011-01-01

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

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

    NARCIS (Netherlands)

    Oleksiak, A.; Klink, P.C.; Postma, A.; Ham, van der I.J.; Lankheet, M.J.M.; Wezel, van R.J.

    2011-01-01

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

  18. Planning Movements in Visual and Physical Space in Monkey Posterior Parietal Cortex.

    Science.gov (United States)

    Kuang, Shenbing; Morel, Pierre; Gail, Alexander

    2016-02-01

    Neurons in the posterior parietal cortex respond selectively for spatial parameters of planned goal-directed movements. Yet, it is still unclear which aspects of the movement the neurons encode: the spatial parameters of the upcoming physical movement (physical goal), or the upcoming visual limb movement (visual goal). To test this, we recorded neuronal activity from the parietal reach region while monkeys planned reaches under either normal or prism-reversed viewing conditions. We found predominant encoding of physical goals while fewer neurons were selective for visual goals during planning. In contrast, local field potentials recorded in the same brain region exhibited predominant visual goal encoding, similar to previous imaging data from humans. The visual goal encoding in individual neurons was neither related to immediate visual input nor to visual memory, but to the future visual movement. Our finding suggests that action planning in parietal cortex is not exclusively a precursor of impending physical movements, as reflected by the predominant physical goal encoding, but also contains spatial kinematic parameters of upcoming visual movement, as reflected by co-existing visual goal encoding in neuronal spiking. The co-existence of visual and physical goals adds a complementary perspective to the current understanding of parietal spatial computations in primates.

  19. Sodium valproate use is associated with reduced parietal lobe thickness and brain volume.

    Science.gov (United States)

    Pardoe, Heath R; Berg, Anne T; Jackson, Graeme D

    2013-05-14

    We hypothesized that total brain volume, white matter volume, and lobar cortical thickness would be different in epilepsy patients. We studied valproate relative to nonvalproate by using patients with epilepsy and healthy controls. Patients with focal intractable epilepsy from a tertiary epilepsy center were the primary group for analysis. A confirmatory analysis was carried out in an independent group of subjects imaged as part of a community-based study of childhood-onset epilepsy. Total brain volume; white matter volume; and frontal, parietal, occipital, and temporal lobe thickness were measured by processing whole-brain T1-weighted MRI using FreeSurfer 5.1. Total brain volume, white matter volume, and parietal thickness were reduced in the valproate group relative to controls and nonvalproate users (valproate, n = 9; nonvalproate, n = 27; controls, n = 45; all male). These findings were confirmed in an independent group (valproate, n = 7; nonvalproate, n = 70; controls, n = 20; all male). Sodium valproate use in epilepsy is associated with parietal lobe thinning, reduced total brain volume, and reduced white matter volume. This study provides Class IV evidence that use of valproate in epilepsy is associated with reduced parietal lobe thickness, total brain volume, and white matter volume.

  20. Alteration of Duration Mismatch Negativity Induced by Transcranial Magnetic Stimulation Over the Left Parietal Lobe.

    Science.gov (United States)

    Oshima, Hirokazu; Shiga, Tetsuya; Niwa, Shin-Ichi; Enomoto, Hiroyuki; Ugawa, Yoshikazu; Yabe, Hirooki

    2017-01-01

    Mismatch negativity (MMN) is generated by a comparison between an incoming sound and the memory trace of preceding sounds stored in sensory memory without any attention to the sound. N100 (N1) is associated with the afferent response to sound onset and reflects early analysis of stimulus characteristics. MMN generators are present in the temporal and frontal lobe, and N1 generators are present in the temporal lobe. The parietal lobe is involved in MMN generation elicited by a change in duration. The anatomical network connecting these areas, lateralization, and the effect of the side of ear stimulation on MMN remain unknown. Thus, we studied the effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) over the left parietal lobe on MMN and N1 in 10 healthy subjects. Low-frequency rTMS over the left parietal lobe decreased the amplitude of MMN following right ear sound stimulation, but the amplitude was unaffected with left ear sound stimulation. We observed no significant changes in the amplitude of N1 or the latency of MMN or N1. These results suggest that low-frequency rTMS over the left parietal lobe modulates the detection of early auditory changes in duration in healthy subjects. Stimulation that is contralateral to the side of the ear experiencing sound may affect the generation of duration MMN more than ipsilateral stimulation. © EEG and Clinical Neuroscience Society (ECNS) 2016.

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

    Science.gov (United States)

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

    2009-01-01

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

  2. The left inferior parietal lobe represents stored hand-postures for object use and action prediction

    NARCIS (Netherlands)

    van Elk, M.

    2014-01-01

    Action semantics enables us to plan actions with objects and to predict others' object-directed actions as well. Previous studies have suggested that action semantics are represented in a fronto-parietal action network that has also been implicated to play a role in action observation. In the

  3. Transfer of cognitive training across magnitude dimensions achieved with concurrent brain stimulation of the parietal lobe.

    Science.gov (United States)

    Cappelletti, Marinella; Gessaroli, Erica; Hithersay, Rosalyn; Mitolo, Micaela; Didino, Daniele; Kanai, Ryota; Cohen Kadosh, Roi; Walsh, Vincent

    2013-09-11

    Improvement in performance following cognitive training is known to be further enhanced when coupled with brain stimulation. Here we ask whether training-induced changes can be maintained long term and, crucially, whether they can extend to other related but untrained skills. We trained overall 40 human participants on a simple and well established paradigm assessing the ability to discriminate numerosity--or the number of items in a set--which is thought to rely on an "approximate number sense" (ANS) associated with parietal lobes. We coupled training with parietal stimulation in the form of transcranial random noise stimulation (tRNS), a noninvasive technique that modulates neural activity. This yielded significantly better and longer lasting improvement (up to 16 weeks post-training) of the precision of the ANS compared with cognitive training in absence of stimulation, stimulation in absence of cognitive training, and cognitive training coupled to stimulation to a control site (motor areas). Critically, only ANS improvement induced by parietal tRNS + Training transferred to proficiency in other parietal lobe-based quantity judgment, i.e., time and space discrimination, but not to quantity-unrelated tasks measuring attention, executive functions, and visual pattern recognition. These results indicate that coupling intensive cognitive training with tRNS to critical brain regions resulted not only in the greatest and longer lasting improvement of numerosity discrimination, but importantly in this enhancement being transferable when trained and untrained abilities are carefully chosen to share common cognitive and neuronal components.

  4. The contribution of the inferior parietal cortex to spoken language production

    NARCIS (Netherlands)

    Geranmayeh, F.; Brownsett, S.L.; Leech, R.; Beckmann, Christian; Woodhead, Z.; Wise, R.J.

    2012-01-01

    This functional MRI study investigated the involvement of the left inferior parietal cortex (IPC) in spoken language production (Speech). Its role has been apparent in some studies but not others, and is not convincingly supported by clinical studies as they rarely include cases with lesions

  5. Reconsidering harbingers of dementia: progression of parietal lobe white matter hyperintensities predicts Alzheimer's disease incidence.

    Science.gov (United States)

    Brickman, Adam M; Zahodne, Laura B; Guzman, Vanessa A; Narkhede, Atul; Meier, Irene B; Griffith, Erica Y; Provenzano, Frank A; Schupf, Nicole; Manly, Jennifer J; Stern, Yaakov; Luchsinger, José A; Mayeux, Richard

    2015-01-01

    Accumulating evidence implicates small vessel cerebrovascular disease, visualized as white matter hyperintensities (WMH) on T2-weighted magnetic resonance imaging, in the pathogenesis and diagnosis of Alzheimer's disease (AD). Cross-sectional volumetric measures of WMH, particularly in the parietal lobes, are associated with increased risk of AD. In the present study, we sought to determine whether the longitudinal regional progression of WMH predicts incident AD above-and-beyond traditional radiological markers of neurodegeneration (i.e., hippocampal atrophy and cortical thickness). Three hundred three nondemented older adults (mean age = 79.24 ± 5.29) received high-resolution magnetic resonance imaging at baseline and then again 4.6 years (standard deviation = 1.01) later. Over the follow-up interval 26 participants progressed to AD. Using structural equation modeling, we calculated latent difference scores of parietal and nonparietal WMH, hippocampus volumes, and cortical thickness values in AD-related regions. Within the structural equation modeling framework, we determined whether baseline or change scores or both predicted AD conversion, while controlling for several time-invariant relevant variables. Smaller baseline hippocampus volume, change in hippocampus volume (i.e., atrophy), higher baseline parietal lobe WMH, and increasing parietal lobe WMH volume but not WMH in other regions or measures of cortical thickness, independently predicted progression to AD. The findings provide strong evidence that regionally accumulating WMH predict AD onset in addition to hallmark neurodegenerative changes typically associated with AD. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Sex Differences in Parietal Lobe Morphology: Relationship to Mental Rotation Performance

    Science.gov (United States)

    Koscik, Tim; O'Leary, Dan; Moser, David J.; Andreasen, Nancy C.; Nopoulos, Peg

    2009-01-01

    Structural magnetic resonance imaging (MRI) studies of the human brain have reported evidence for sexual dimorphism. In addition to sex differences in overall cerebral volume, differences in the proportion of gray matter (GM) to white matter (WM) volume have been observed, particularly in the parietal lobe. To our knowledge there have been no…

  7. Cortical infarction of the right parietal lobe and neurogenic heart disease: A report of three cases.

    Science.gov (United States)

    Li, Fang; Jia, Yujie

    2012-04-25

    Three male patients were diagnosed with new cortical infarctions of the right parietal lobe on the basis of head magnetic resonance imaging; high-intensity signals indicating lesions in the right parietal lobe were noted on diffusion-weighted images at admission. Two of them presented with left hand weakness, and one exhibited left upper limb weakness. Treatment for improving blood supply to the brain was administered. One patient died suddenly because of ventricular fibrillation 3 days after admission. The other two patients had increased troponin levels and abnormal electrocardiograms, and were diagnosed with acute myocardial infarction half a month after admission. When lesions exist in field 7 of the parietal cortex (resulting in paralysis of the contralateral hand), the sympathetic center of the posterior lateral nucleus of the hypothalamus demonstrates compensatory excitement, which easily causes tachyarrhythmia and sudden death. Our experimental findings indicate that close electrocardiograph monitoring and cerebral infarction treatment should be standard procedures to predict and help prevent heart disease in patients with cerebral infarction in the right parietal lobe and left upper limb weakness as the main complaint.

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

    Science.gov (United States)

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

    2012-01-01

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

  9. An atretic parietal cephalocele associated with multiple intracranial and eye anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Saatci, I.; Yelgec, S.; Aydin, K. [Hacettepe University Hospital, Department of Radiology, Ankara (Turkey); Akalan, N. [Hacettepe University Hospital, Department of Neurosurgery, Ankara (Turkey)

    1998-12-01

    We present the cranial MRI findings in a 4-month-old girl with an atretic parietal cephalocele associated with multiple cerebral and ocular anomalies including lobar holoprosencephaly, a Dandy-Walker malformation, agenesis of the corpus callosum, grey-matter heterotopia, extra-axial cysts in various locations, bilateral microphthalmia and a retroocular cyst. (orig.) With 1 fig., 12 refs.

  10. [Mother and son with enlarged parietal foramina, persistent fetal vein, and ALX4 mutation].

    Science.gov (United States)

    Morita, Motoaki; Nanba, Eiji; Adachi, Kaori; Ohno, Kousaku

    2016-05-01

    Enlarged parietal foramina (EPF) are rare congenital skull defects. These round or oval defects are situated on each parietal bone approximately 1 cm from the midline. Most patients with EPF have a positive family history. The condition is inherited as an autosomal dominant trait with relatively high, but not full, penetrance. Mutation in either MSX2 or ALX4 genes is associated with enlarged parietal foramina. Case 1 is a boy who was noticed to have a large anterior fontanelle, large posterior fontanelle, and widely opened sagittal suture at 2 months. During development, the anterior fontanelle and sagittal suture closed at 3 years and the posterior fontanelle subsequently divided into two foramina with ossification of the midline bridge by 4 years. The foramina were about 2.5 x 2.5 cm in diameter at 8 years. Case 2 is the 34-year-old mother of Case 1. She showed similar bone defects in her cranium, again about 2.5 x 2.5 cm in diameter. Neither patient showed any neurological symptoms. Genetic analysis revealed a mutation in the ALX4 gene in both patients, and magnetic resonance imaging showed a persistent falcine sinus and a hypoplastic straight sinus. Further evaluation revealed that the mother of Case 2 also had a mutation in the ALX4 gene, but no enlarged parietal foramina. Although high penetrance of this condition has been reported, this family suggests incomplete penetrance of this disorder.

  11. Molecular insights into evolution of the vertebrate gut: focus on stomach and parietal cells in the marsupial, Macropus eugenii.

    Science.gov (United States)

    Kwek, Joly; De Iongh, Robbert; Nicholas, Kevin; Familari, Mary

    2009-09-15

    Gastrulation in vertebrate embryos results in the formation of the primary germ layers: ectoderm, mesoderm and endoderm, which contain the progenitors of the tissues of the entire fetal body. Extensive studies undertaken in Xenopus, zebrafish and mouse have revealed a high degree of conservation in the genes and cellular mechanisms regulating endoderm formation. Nodal, Mix and Sox gene factor families have been implicated in the specification of the endoderm across taxa. Considerably less is known about endoderm development in marsupials. In this study we review what is known about the molecular aspects of endoderm development, focusing on evolution and development of the stomach and parietal cells and highlight recent studies on parietal cells in the stomach of Tammar Wallaby, Macropus eugenii. Although the regulation of parietal cells has been extensively studied, very little is known about the regulation of parietal cell differentiation. Intriguingly, during late-stage forestomach maturation in M. eugenii, there is a sudden and rapid loss of parietal cells, compared with the sharp increase in parietal cell numbers in the hindstomach region. This has provided a unique opportunity to study the development and regulation of parietal cell differentiation. A PCR-based subtractive hybridization strategy was used to identify candidate genes involved in this phenomenon. This will allow us to dissect the molecular mechanisms that underpin regulation of parietal cell development and differentiation, which have been a difficult process to study and provide markers that can be used to study the evolutionary origin of these cells in vertebrates.

  12. Mental "Space" Travel: Damage to Posterior Parietal Cortex Prevents Egocentric Navigation and Reexperiencing of Remote Spatial Memories

    Science.gov (United States)

    Ciaramelli, Elisa; Rosenbaum, R. Shayna; Solcz, Stephanie; Levine, Brian; Moscovitch, Morris

    2010-01-01

    The ability to navigate in a familiar environment depends on both an intact mental representation of allocentric spatial information and the integrity of systems supporting complementary egocentric representations. Although the hippocampus has been implicated in learning new allocentric spatial information, converging evidence suggests that the…

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

    Directory of Open Access Journals (Sweden)

    Agustina Birba

    2017-06-01

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

  14. Unexpected novelty and familiarity orienting responses in lateral parietal cortex during recognition judgment.

    Science.gov (United States)

    Jaeger, Antonio; Konkel, Alex; Dobbins, Ian G

    2013-05-01

    The role of lateral parietal cortex during recognition memory is heavily debated. We examined parietal activation during an Explicit Memory Cueing recognition paradigm that biases participants towards expecting novel or familiar stimuli on a trial-by-trial basis using anticipatory cues ("Likely Old", "Likely New"), compared to trials with neutral cues ("????"). Three qualitatively distinct patterns were observed in the left lateral parietal cortex. An unexpected novelty response occurred in left anterior intraparietal cortex (IPS)/post-central gyrus (PoCG) in which greater activation was observed for new vs. old materials following the "Likely Old" cue, but not following the "Likely New" cue. In contrast, anterior angular gyrus demonstrated an unexpected familiarity response with greater activation for old vs. new materials following the "Likely New" cue, but not the "Likely Old" cue. Thus these two regions demonstrated increased responses that were selective for either new or old materials respectively, but only when they were unexpected. In contrast, a mid IPS area demonstrated greater response for whichever class of memoranda was unanticipated given the cue condition (an unexpected memory response). Analogous response patterns in regions outside of parietal cortex, and the results of a resting state connectivity analysis, suggested these three response patterns were associated with visuo-spatial orienting following unexpected novelty, source monitoring operations following unexpected familiarity, and general executive control processes following violated expectations. These findings support a Memory Orienting Model of the left lateral parietal cortex in which the region is linked to the investigation of unexpected novelty or familiarity in the environment.

  15. Contribution of the posterior parietal cortex in reaching, grasping, and using objects and tools

    Directory of Open Access Journals (Sweden)

    Guy eVingerhoets

    2014-03-01

    Full Text Available Neuropsychological and neuroimaging data suggest a differential contribution of posterior parietal regions during the different components of a transitive gesture. Reaching requires the integration of object location and body position coordinates and reaching tasks elicit bilateral activation in different foci along the intraparietal sulcus. Grasping requires a visuomotor match between the object’s shape and the hand’s posture. Lesion studies and neuroimaging confirm the importance of the anterior part of the intraparietal sulcus for human grasping. Reaching and grasping reveal bilateral activation that is generally more prominent on the side contralateral to the hand used or the hemifield stimulated. Purposeful behavior with objects and tools can be assessed in a variety of ways, including actual use, pantomimed use, and pure imagery of manipulation. All tasks have been shown to elicit robust activation over the left parietal cortex in neuroimaging, but lesion studies have not always confirmed these findings. Compared to pantomimed or imagined gestures, actual object and tool use typically produces activation over the left primary somatosensory region. Neuroimaging studies on pantomiming or imagery of tool use in healthy volunteers revealed neural responses in possibly separate foci in the left supramarginal gyrus. In sum, the parietal contribution of reaching and grasping of objects seems to depend on a bilateral network of intraparietal foci that appear organized along gradients of sensory and effector preferences. Dorsal and medial parietal cortex appears to contribute to the online monitoring/adjusting of the ongoing prehensile action, whereas the functional use of objects and tools seems to involve the inferior lateral parietal cortex. This functional input reveals a clear left lateralized activation pattern that may be tuned to the integration of acquired knowledge in the planning and guidance of the transitive movement.

  16. Contribution of the posterior parietal cortex in reaching, grasping, and using objects and tools.

    Science.gov (United States)

    Vingerhoets, Guy

    2014-01-01

    Neuropsychological and neuroimaging data suggest a differential contribution of posterior parietal regions during the different components of a transitive gesture. Reaching requires the integration of object location and body position coordinates and reaching tasks elicit bilateral activation in different foci along the intraparietal sulcus. Grasping requires a visuomotor match between the object's shape and the hand's posture. Lesion studies and neuroimaging confirm the importance of the anterior part of the intraparietal sulcus for human grasping. Reaching and grasping reveal bilateral activation that is generally more prominent on the side contralateral to the hand used or the hemifield stimulated. Purposeful behavior with objects and tools can be assessed in a variety of ways, including actual use, pantomimed use, and pure imagery of manipulation. All tasks have been shown to elicit robust activation over the left parietal cortex in neuroimaging, but lesion studies have not always confirmed these findings. Compared to pantomimed or imagined gestures, actual object and tool use typically produces activation over the left primary somatosensory region. Neuroimaging studies on pantomiming or imagery of tool use in healthy volunteers revealed neural responses in possibly separate foci in the left supramarginal gyrus. In sum, the parietal contribution of reaching and grasping of objects seems to depend on a bilateral network of intraparietal foci that appear organized along gradients of sensory and effector preferences. Dorsal and medial parietal cortex appears to contribute to the online monitoring/adjusting of the ongoing prehensile action, whereas the functional use of objects and tools seems to involve the inferior lateral parietal cortex. This functional input reveals a clear left lateralized activation pattern that may be tuned to the integration of acquired knowledge in the planning and guidance of the transitive movement.

  17. Immune response to Mycobacterium tuberculosis infection in the parietal pleura of patients with tuberculous pleurisy.

    Directory of Open Access Journals (Sweden)

    Gaetano Caramori

    Full Text Available The T lymphocyte-mediated immune response to Mycobacterium tuberculosis infection in the parietal pleura of patients with tuberculous pleurisy is unknown. The aim of this study was to investigate the immune response in the parietal pleura of tuberculous pleurisy compared with nonspecific pleuritis. We have measured the numbers of inflammatory cells particularly T-cell subsets (Th1/Th2/Th17/Treg cells in biopsies of parietal pleura obtained from 14 subjects with proven tuberculous pleurisy compared with a control group of 12 subjects with nonspecific pleuritis. The number of CD3+, CD4+ and CCR4+ cells and the expression of RORC2 mRNA were significantly increased in the tuberculous pleurisy patients compared with the nonspecific pleuritis subjects. The number of toluidine blue+ cells, tryptase+ cells and GATA-3+ cells was significantly decreased in the parietal pleura of patients with tuberculous pleurisy compared with the control group of nonspecific pleuritis subjects. Logistic regression with receiver operator characteristic (ROC analysis for the three single markers was performed and showed a better performance for GATA-3 with a sensitivity of 75%, a specificity of 100% and an AUC of 0.88. There was no significant difference between the two groups of subjects in the number of CD8, CD68, neutrophil elastase, interferon (IFN-γ, STAT4, T-bet, CCR5, CXCR3, CRTH2, STAT6 and FOXP3 positive cells. Elevated CD3, CD4, CCR4 and Th17 cells and decreased mast cells and GATA-3+ cells in the parietal pleura distinguish patients with untreated tuberculous pleurisy from those with nonspecific pleuritis.

  18. Immune response to Mycobacterium tuberculosis infection in the parietal pleura of patients with tuberculous pleurisy.

    Science.gov (United States)

    Caramori, Gaetano; Lasagna, Lisa; Casalini, Angelo G; Adcock, Ian M; Casolari, Paolo; Contoli, Marco; Tafuro, Federica; Padovani, Anna; Chung, Kian Fan; Barnes, Peter J; Papi, Alberto; Rindi, Guido; Bertorelli, Giuseppina

    2011-01-01

    The T lymphocyte-mediated immune response to Mycobacterium tuberculosis infection in the parietal pleura of patients with tuberculous pleurisy is unknown. The aim of this study was to investigate the immune response in the parietal pleura of tuberculous pleurisy compared with nonspecific pleuritis. We have measured the numbers of inflammatory cells particularly T-cell subsets (Th1/Th2/Th17/Treg cells) in biopsies of parietal pleura obtained from 14 subjects with proven tuberculous pleurisy compared with a control group of 12 subjects with nonspecific pleuritis. The number of CD3+, CD4+ and CCR4+ cells and the expression of RORC2 mRNA were significantly increased in the tuberculous pleurisy patients compared with the nonspecific pleuritis subjects. The number of toluidine blue+ cells, tryptase+ cells and GATA-3+ cells was significantly decreased in the parietal pleura of patients with tuberculous pleurisy compared with the control group of nonspecific pleuritis subjects. Logistic regression with receiver operator characteristic (ROC) analysis for the three single markers was performed and showed a better performance for GATA-3 with a sensitivity of 75%, a specificity of 100% and an AUC of 0.88. There was no significant difference between the two groups of subjects in the number of CD8, CD68, neutrophil elastase, interferon (IFN)-γ, STAT4, T-bet, CCR5, CXCR3, CRTH2, STAT6 and FOXP3 positive cells. Elevated CD3, CD4, CCR4 and Th17 cells and decreased mast cells and GATA-3+ cells in the parietal pleura distinguish patients with untreated tuberculous pleurisy from those with nonspecific pleuritis.

  19. Sobredentadura total superior implantosoportada Superior total overdenture on implants

    Directory of Open Access Journals (Sweden)

    Luis Orlando Rodríguez García

    2010-06-01

    Full Text Available Se presenta un caso de un paciente desdentado total superior, rehabilitado en la consulta de implantología de la Clínica "Pedro Ortiz" del municipio Habana del Este en Ciudad de La Habana, Cuba, en el año 2009, mediante prótesis sobre implantes osteointegrados, técnica que se ha incorporado a la práctica estomatológica en Cuba como alternativa al tratamiento convencional en los pacientes desdentados totales. Se siguió un protocolo que comprendió una fase quirúrgica, procedimiento con o sin realización de colgajo y carga precoz o inmediata. Se presenta un paciente masculino de 56 años de edad, que acudió a la consulta multidisciplinaria, preocupado, porque se le habían elaborado tres prótesis en los últimos dos años y ninguna reunía los requisitos de retención que él necesitaba para sentirse seguro y cómodo con las mismas. El resultado final fue la satisfacción total del paciente, con el mejoramiento de la calidad estética y funcional.This is the case of a total maxilla edentulous patient seen in consultation of the "Pedro Ortíz" Clinic Implant of Habana del Este municipality in 2009 and con rehabilitation by prosthesis over osteointegration implants added to stomatology practice in Cuba as an alternative to conventional treatment in patients totally edentulous. We follow a protocol including a surgery or surgical phase, technique without or with flap creation and early or immediate load. This is a male patient aged 56 came to our multidisciplinary consultation worried because he had three prostheses in last two years and any fulfilled the requirements of retention to feel safe and comfortable with prostheses. The final result was the total satisfaction of rehabilitated patient improving its aesthetic and functional quality.

  20. Effect of Kangxin Capsule(康欣胶囊) on the Expression of Nerve Growth Factors in Parietal Lobe of Cortex and Hippocampus CA1 Area of Vascular Dementia Model Rats

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To observe the effect of Kangxin Capsule (康欣胶囊, KXC) on the expression of nerve growth factor (NGF) as well as the morphology and amount of nerve synapse in the cortical parietal lobe and hippocampus CA1 area of vascular dementia (VD) model rats. Methods: The model rats of VD made by photochemical reaction technique were randomly divided into five groups: the model group (MG), the high-dose, middle-dose and low-dose KXC groups (HDG, MDG and LDG), and the Western medicine hydergin control group (WMG). They were treated respectively with distilled water, high, middle and low dosage of KXC suspended liquid, and hydergin for a month. Besides, a blank group consisting of normal (non-model)rats was set up for control (CG). The ultrastructure of nerve synapse in the cortical parietal lobe and hippocampus CA1 area of the rats were observed and its density estimated. The condition of NGF positive neurons in the above-mentioned two regions were also observed by immunohistochemical stain. Results: All the KXC or hydergin treated groups demonstrated a normal amount of nerve synapse with integral structure in the cortical parietal lobe and hippocampus CA1 area, which approached that in the CG and was superior to that in the MG. Also, the NGF positive neuron in all the treated groups was much more than that in MG with significant difference ( P<0.01 ), approaching to that in the CG. Conclusion: KXC could elevate the expression of NGF in the cortical parietal lobe and hippocampus CA1 area, preserve the number and morphology of synapse,thus to protect the function of nerve system from ischemic injury.

  1. Irradiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Howe, L.M

    2000-07-01

    There is considerable interest in irradiation effects in intermetallic compounds from both the applied and fundamental aspects. Initially, this interest was associated mainly with nuclear reactor programs but it now extends to the fields of ion-beam modification of metals, behaviour of amorphous materials, ion-beam processing of electronic materials, and ion-beam simulations of various kinds. The field of irradiation damage in intermetallic compounds is rapidly expanding, and no attempt will be made in this chapter to cover all of the various aspects. Instead, attention will be focused on some specific areas and, hopefully, through these, some insight will be given into the physical processes involved, the present state of our knowledge, and the challenge of obtaining more comprehensive understanding in the future. The specific areas that will be covered are: point defects in intermetallic compounds; irradiation-enhanced ordering and irradiation-induced disordering of ordered alloys; irradiation-induced amorphization.

  2. Hippocampal Temporal-Parietal Junction Interaction in the Production of Psychotic Symptoms: A Framework for Understanding the Schizophrenic Syndrome

    Directory of Open Access Journals (Sweden)

    Cynthia Gayle Wible

    2012-06-01

    Full Text Available A framework is described for understanding the schizophrenic syndrome at the brain systems level. It is hypothesized that over-activation of dynamic gesture and social perceptual processes in the temporal-parietal occipital junction (TPJ, posterior superior temporal sulcus (PSTS and surrounding regions produce the syndrome (including positive and negative symptoms, their prevalence, prodromal signs and cognitive deficits. Hippocampal system hyper-activity and atrophy have been consistently found in schizophrenia. Hippocampal activity is highly related to activity in the TPJ and may be a source of over-excitation of the TPJ and surrounding regions. Strong evidence for this comes from in-vivo recordings in humans during psychotic episodes. The TPJ and PSTS play a key role in the perception (and production of dynamic social, emotional and attentional gestures for the self and others (e.g., body/face/eye gestures, audiovisual speech, prosody. The single cell representation of dynamic gestures is multimodal (auditory, visual, tactile, matching the predominant hallucinatory categories in schizophrenia. Inherent in the single cell perceptual signal of dynamic gesture representations is a computation of intention, agency, and anticipation or expectancy (for the self and others. The neurons are also tuned or biased to detect threat related emotions. Abnormal over-activation in this system could produce the conscious hallucination of a voice (audiovisual speech, person or a touch. Over-activation could interfere with attentional/emotional gesture perception and production (negative symptoms. It could produce the unconscious feeling of being watched, followed or of a social situation unfolding along with accompanying perception of intent and agency inherent in those representations (delusions. Cognitive disturbances in attention, predictive social processing, agency, working memory, and a bias toward the perception of threat would also be predicted.

  3. Las pinturas de la cueva de Porto Badisco y el arte parietal «esquemático» español

    Directory of Open Access Journals (Sweden)

    Antonio BELTRÁN MARTÍNEZ

    2009-12-01

    Full Text Available En la evolución del arte parietal prehistórico se produjo una secuencia cronológica cuyos momentos culturales pueden cubrir todo el proceso o solamente una parte de él, según las zonas geográficas que se analicen. La Península Ibérica posee ejemplos desde el Paleolítico Superior hasta la Edad del Hierro, a los que, convencionalmente, se ha bautizado con nombres de contenido estético, discutibles, pero imprescindibles a la hora de establecer hipótesis; así el arte «naturalista» del Paleolítico Superior, el «impresionista» de los abrigos levantinos meso-neolíticos, y el «esquemático» del Neolítico al bronce, sin contar con los «petroglifos» o insculturas sobre roca y preferentemente al aire libre, de Galicia y de las Islas Canarias.

  4. Temporo-parietal and fronto-parietal lobe contributions to theory of mind and executive control: an fMRI study of verbal jokes.

    Science.gov (United States)

    Chan, Yu-Chen; Lavallee, Joseph P

    2015-01-01

    '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 (BJs), exaggeration jokes (EJs), and ambiguity jokes (AJs). 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 BJs, suggesting involvement of these regions with 'theory of mind' processing. The fronto-parietal lobe (IPL and IFG) was associated with both EJs and AJs, 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, and parahippocampal gyrus. These results allow a more precise account of the neural processes required to support the particular cognitive operations required for the understanding of different types of humor.

  5. Time Course of the Involvement of the Right Anterior Superior Temporal Gyrus and the Right Fronto-Parietal Operculum in Emotional Prosody Perception

    NARCIS (Netherlands)

    Hoekert, Marjolijn; Bais, Leonie; Kahn, Rene S.; Aleman, Andre

    2008-01-01

    In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody) conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional

  6. Neural correlates associated with superior tactile symmetry perception in the early blind.

    Science.gov (United States)

    Bauer, Corinna; Yazzolino, Lindsay; Hirsch, Gabriella; Cattaneo, Zaira; Vecchi, Tomaso; Merabet, Lotfi B

    2015-02-01

    Symmetry is an organizational principle that is ubiquitous throughout the visual world. However, this property can also be detected through non-visual modalities such as touch. The role of prior visual experience on detecting tactile patterns containing symmetry remains unclear. We compared the behavioral performance of early blind and sighted (blindfolded) controls on a tactile symmetry detection task. The tactile patterns used were similar in design and complexity as in previous visual perceptual studies. The neural correlates associated with this behavioral task were identified with functional magnetic resonance imaging (fMRI). In line with growing evidence demonstrating enhanced tactile processing abilities in the blind, we found that early blind individuals showed significantly superior performance in detecting tactile symmetric patterns compared to sighted controls. Furthermore, comparing patterns of activation between these two groups identified common areas of activation (e.g. superior parietal cortex) but key differences also emerged. In particular, tactile symmetry detection in the early blind was also associated with activation that included peri-calcarine cortex, lateral occipital (LO), and middle temporal (MT) cortex, as well as inferior temporal and fusiform cortex. These results contribute to the growing evidence supporting superior behavioral abilities in the blind, and the neural correlates associated with crossmodal neuroplasticity following visual deprivation.

  7. Brain morphology and neuropsychological profiles in a family displaying dyslexia and superior nonverbal intelligence.

    Science.gov (United States)

    Craggs, Jason G; Sanchez, Juliana; Kibby, Michelle Y; Gilger, Jeffrey W; Hynd, George W

    2006-11-01

    Behavioral research suggests that individuals with dyslexia may have exceptional skills in nonverbal cognitive processes, while genetic studies have noted that giftedness, high IQ and/or special talents tend to run in families. Taken together, these results suggest that persons within families (particularly offspring) may share similar cortical systems supporting those functions. Postmortem and in vivo imaging studies have linked dyslexia to abnormalities in the structures associated with the parietal operculum (PO) (e.g., planum temporale, supramarginal gyrus, and angular gyrus). In this paper we present data on a single family showing a link between dyslexia, superior nonverbal IQ and atypical PO presentation. We consider the psychometric and neurological patterns of this family as a tentative etiological test of the putative dyslexia-talent association.

  8. Paso superior en una ladera

    Directory of Open Access Journals (Sweden)

    Bender, O.

    1965-07-01

    Full Text Available The Redwood highway, through the Californian forest, runs on a viaduct, as it crosses a mountain slope of about 45° inclination. The firm ground is fairly deep, and as an additional constructional difficulty, it was necessary to respect the natural beauty of the countryside. A structure of portal frames were built, forming a number of short spans. These spans were bridged with metal girders, on which a 19 m wide deck was placed. The columns are hollow and have a transversal cross beam, to join each pair. There was difficulty in excavating the foundations for the columns, as it was necessary to dig through the soft top soil, and also prevent this soil from hurting the trunks of the forest trees. Another significant difficulty in the construction of this viaduct was the access to the working site, since there were no suitable platforms from which to operate the appropriate machinery. This made it necessary to do a lot of the work by manual operation. As one of the edges of the deck is very close to the mountain side, a supporting beam was erected on this side. It was made of concrete, on metal piles. The formwork for the deck structure was placed on the concrete stems of the supporting piles.La autopista denominada Redwood (California salva, con un paso superior, la ladera de un bosque cuya pendiente es del 1/1. El terreno firme se halla a bastante profundidad, añadiéndose, a los naturales problemas de la construcción, el imperativo de respetar la belleza agreste del paraje. La solución adoptada consiste en una estructura porticada, con varios tramos de pequeñas luces, salvados con vigas metálicas, sobre los que se coloca la losa del tablero, de 19 m de anchura total. Los soportes están constituidos por pórticos de dos montantes huecos (con bases de hormigón en masa por debajo del suelo, hasta el firme coronados por un cabezal. La perforación de pozos para el hormigonado de los montantes presentaba la dificultad de atravesar el terreno

  9. Making sense of another mind: the role of the right temporo-parietal junction.

    Science.gov (United States)

    Saxe, Rebecca; Wexler, Anna

    2005-01-01

    Human adults conceive of one another as beings with minds, and attribute to one another mental states like perceptions, desires and beliefs. That is, we understand other people using a 'Theory of Mind'. The current study investigated the contributions of four brain regions to Theory of Mind reasoning. The right temporo-parietal junction (RTPJ) was recruited selectively for the attribution of mental states, and not for other socially relevant facts about a person, and the response of the RTPJ was modulated by the congruence or incongruence of multiple relevant facts about the target's mind. None of the other three brain regions commonly implicated in Theory of Mind reasoning--the left temporo-parietal junction (LTPJ), posterior cingulate (PC) and medial prefrontal cortex (MPFC)--showed an equally selective profile of response. The implications of these results for an alternative theory of reasoning about other minds--Simulation Theory--are discussed.

  10. Decoding the view expectation during learned maze navigation from human fronto-parietal network.

    Science.gov (United States)

    Shikauchi, Yumi; Ishii, Shin

    2015-12-03

    Humans use external cues and prior knowledge about the environment to monitor their positions during spatial navigation. View expectation is essential for correlating scene views with a cognitive map. To determine how the brain performs view expectation during spatial navigation, we applied a multiple parallel decoding technique to functional magnetic resonance imaging (fMRI) when human participants performed scene choice tasks in learned maze navigation environments. We decoded participants' view expectation from fMRI signals in parietal and medial prefrontal cortices, whereas activity patterns in occipital cortex represented various types of external cues. The decoder's output reflected participants' expectations even when they were wrong, corresponding to subjective beliefs opposed to objective reality. Thus, view expectation is subjectively represented in human brain, and the fronto-parietal network is involved in integrating external cues and prior knowledge during spatial navigation.

  11. Complementary roles for primate frontal and parietal cortex in guarding working memory from distractor stimuli.

    Science.gov (United States)

    Jacob, Simon Nikolas; Nieder, Andreas

    2014-07-02

    Prefrontal cortex (PFC) and posterior parietal cortex are important for maintaining behaviorally relevant information in working memory. Here, we challenge the commonly held view that suppression of distractors by PFC neurons is the main mechanism underlying the filtering of task-irrelevant information. We recorded single-unit activity from PFC and the ventral intraparietal area (VIP) of monkeys trained to resist distracting stimuli in a delayed-match-to-numerosity task. Surprisingly, PFC neurons preferentially encoded distractors during their presentation. Shortly after this interference, however, PFC neurons restored target information, which predicted correct behavioral decisions. In contrast, most VIP neurons only encoded target numerosities throughout the trial. Representation of target information in VIP was the earliest and most reliable neuronal correlate of behavior. Our data suggest that distracting stimuli can be bypassed by storing and retrieving target information, emphasizing active maintenance processes during working memory with complementary functions for frontal and parietal cortex in controlling memory content.

  12. Psychic tonus, body schema and the parietal lobes: a multiple lesion case analysis.

    Science.gov (United States)

    Braun, C M J; Desjardins, S; Gaudelet, S; Guimond, A

    2007-01-01

    The psychic tonus model (Braun and colleagues, 1999, 2002, 2003, 2006) states that the left hemisphere is a "booster" of internal experience and behavior in general, and that the right hemisphere is a "dampener". Twenty-five patients with a "positive" extreme disturbance of body schema (somatoparaphrenia) and 37 patients with a "negative" disturbance of body schema (autotopagnosia or Gerstmann's syndrome), all following a unilateral parietal lesion, were found in the literature and were analyzed to test predictions from Braun's "psychic tonus" model. As expected, patients with a positive syndrome had a right hemisphere lesion significantly more frequently, and those with a negative syndrome had a left hemisphere lesion significantly more frequently. Thus the psychic tonus model of hemispheric specialization, previously supported with regard to psychomotor baseline, libido, talkativeness, memory, auditory and visual perceptual tonus, now incorporates the tonus of representation of the body (body schema) in the parietal lobes.

  13. Acute parietal lobe infarction presenting as Gerstmann's syndrome and cognitive decline mimicking senile dementia.

    Science.gov (United States)

    Chen, Tien-Yu; Chen, Chun-Yen; Yen, Che-Hung; Kuo, Shin-Chang; Yeh, Yi-Wei; Chang, Serena; Huang, San-Yuan

    2013-01-01

    Gerstmann's syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. An elderly man with a history of several cardiovascular diseases was initially brought to the psychiatric outpatient department by his family because of worsening of recent memory, executive function, and mixed anxious-depressive mood. Gerstmann's syndrome without obvious motor function impairment and dementia-like features could be observed at first. Emergent brain computed tomography scan revealed new left-middle cerebral artery infarction over the left posterior parietal lobe. This case reminds us that acute cerebral infarction involving the parietal lobe may present as Gerstmann's syndrome accompanied by cognitive decline mimicking dementia. As a result, emergent organic workups should be arranged, especially for elderly patients at high risk for cerebral vascular accident.

  14. Decision and action planning signals in human posterior parietal cortex during delayed perceptual choices.

    Science.gov (United States)

    Tosoni, Annalisa; Corbetta, Maurizio; Calluso, Cinzia; Committeri, Giorgia; Pezzulo, Giovanni; Romani, G L; Galati, Gaspare

    2014-04-01

    During simple perceptual decisions, sensorimotor neurons in monkey fronto-parietal cortex represent a decision variable that guides the transformation of sensory evidence into a motor response, supporting the view that mechanisms for decision-making are closely embedded within sensorimotor structures. Within these structures, however, decision signals can be dissociated from motor signals, thus indicating that sensorimotor neurons can play multiple and independent roles in decision-making and action selection/planning. Here we used functional magnetic resonance imaging to examine whether response-selective human brain areas encode signals for decision-making or action planning during a task requiring an arbitrary association between face pictures (male vs. female) and specific actions (saccadic eye vs. hand pointing movements). The stimuli were gradually unmasked to stretch the time necessary for decision, thus maximising the temporal separation between decision and action planning. Decision-related signals were measured in parietal and motor/premotor regions showing a preference for the planning/execution of saccadic or pointing movements. In a parietal reach region, decision-related signals were specific for the stimulus category associated with its preferred pointing response. By contrast, a saccade-selective posterior intraparietal sulcus region carried decision-related signals even when the task required a pointing response. Consistent signals were observed in the motor/premotor cortex. Whole-brain analyses indicated that, in our task, the most reliable decision signals were found in the same neural regions involved in response selection. However, decision- and action-related signals within these regions can be dissociated. Differences between the parietal reach region and posterior intraparietal sulcus plausibly depend on their functional specificity rather than on the task structure. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons

  15. Histiocitosis de células de langerhans en hueso parietal

    Directory of Open Access Journals (Sweden)

    José Luis Quirós Alpízar

    2012-03-01

    Full Text Available La Histiocitosis de Células de Langerhans es un grupo de enfermedades con un compromiso mono o multisistémico; presenta manifestaciones clínicas y complicaciones que varían según el tejido afectado y la extensión de la lesión; caracterizada por la proliferación de células de Langerhans. Se reporta el caso de una paciente femenina de 2 años y medio de edad, que presenta una masa de 6-7 cm en la zona parietal izquierda, dolorosa, que deforma la anatomía craneal; el cuadro evolucionó en 22 días y asoció anorexia. Un estudio por Tomografía Axial Computarizada, mostró una fractura del hueso parietal asociada a un tumor homogéneo sólido en los tejidos blandos adyacentes, sin calcificaciones. Se realizó una resección tumoral, craneotomía y craneoplastia. Los estudios inmunohistoquimicos demostraron células S100, CD1a y CD68 positivasThe Langerhans Cell Histiocytosis is a group of diseases with a single or multisystem involvement, it´s clinic and complications vary depending on the tissue affected and the extent of the injury. The case of a 2 ½ years old female patient was presented, with a mass on the skull in the left parietal area of 22 days, 6-7 cm long, painful, deforms facial image and loss of appetite. The CT scan showed a fracture of the parietal bone, increase of homogeneous solid volume without calcification. The treatment was a tumor resection, craniotomy and cranioplasty, the histopathological study showed immunohistochemically cells S100, CD1a and CD68 positive

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

    Science.gov (United States)

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

    2014-12-01

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

  17. Human Topological Task Adapted for Rats: Spatial Information Processes of the Parietal Cortex

    OpenAIRE

    Goodrich-Hunsaker, Naomi J.; Howard, Brian P.; Hunsaker, Michael R.; Kesner, Raymond P.

    2008-01-01

    Human research has shown that lesions of the parietal cortex disrupt spatial information processing, specifically topological information. Similar findings have been found in nonhumans. It has been difficult to determine homologies between human and non-human mnemonic mechanisms for spatial information processing because methodologies and neuropathology differ. The first objective of the present study was to adapt a previously established human task for rats. The second objective was to bette...

  18. The Effect of 10 Hz Repetitive Transcranial Magnetic Stimulation of Posterior Parietal Cortex on Visual Attention

    OpenAIRE

    Isabel Dombrowe; Georgiana Juravle; Mohsen Alavash; Carsten Gießing; Claus C Hilgetag

    2015-01-01

    Repetitive transcranial magnetic stimulation (rTMS) of the posterior parietal cortex (PPC) at frequencies lower than 5 Hz transiently inhibits the stimulated area. In healthy participants, such a protocol can induce a transient attentional bias to the visual hemifield ipsilateral to the stimulated hemisphere. This bias might be due to a relatively less active stimulated hemisphere and a relatively more active unstimulated hemisphere. In a previous study, Jin and Hilgetag (2008) tried to switc...

  19. Functional rather than effector-specific organization of human posterior parietal cortex

    OpenAIRE

    Heed, T.; Beurze, S.M.; Toni, I; Roder, B.; Medendorp, Pieter

    2011-01-01

    Neurophysiological and neuroimaging studies have shown that the posterior parietal cortex (PPC) distinguishes between the planning of eye and hand movements. This distinction has usually been interpreted as evidence for a modular, effector-specific organization of this cerebral region. However, the eyes differ markedly from other body parts both in terms of their functional purpose and with regard to the spatial transformations required to plan goal-directed movements. PPC may therefore provi...

  20. Human Topological Task Adapted for Rats: Spatial Information Processes of the Parietal Cortex

    OpenAIRE

    Goodrich-Hunsaker, Naomi J.; Howard, Brian P.; Hunsaker, Michael R.; Kesner, Raymond P.

    2008-01-01

    Human research has shown that lesions of the parietal cortex disrupt spatial information processing, specifically topological information. Similar findings have been found in nonhumans. It has been difficult to determine homologies between human and non-human mnemonic mechanisms for spatial information processing because methodologies and neuropathology differ. The first objective of the present study was to adapt a previously established human task for rats. The second objective was to bette...

  1. Trepanation and enlarged parietal foramen on skulls from the Loyalty Islands (Melanesia).

    Science.gov (United States)

    Vasilyev, Sergey V; Sviridov, Alexey A

    2017-06-01

    The goal of this study is a comprehensive examination of openings discovered on two skulls in the collection of skeletal remains from the Loyalty Islands (Melanesia). The skull No. 1524 displayed an evidence of successful trepanation, and the skull No. 7985 revealed openings that were reminiscent of a trepanation, however, we are inclined to believe that in the latter case we are dealing with a rare genetic anomaly - enlarged parietal foramen.

  2. The Pivotal Role of the Right Parietal Lobe in Temporal Attention.

    Science.gov (United States)

    Agosta, Sara; Magnago, Denise; Tyler, Sarah; Grossman, Emily; Galante, Emanuela; Ferraro, Francesco; Mazzini, Nunzia; Miceli, Gabriele; Battelli, Lorella

    2017-05-01

    The visual system is extremely efficient at detecting events across time even at very fast presentation rates; however, discriminating the identity of those events is much slower and requires attention over time, a mechanism with a much coarser resolution [Cavanagh, P., Battelli, L., & Holcombe, A. O. Dynamic attention. In A. C. Nobre & S. Kastner (Eds.), The Oxford handbook of attention (pp. 652-675). Oxford: Oxford University Press, 2013]. Patients affected by right parietal lesion, including the TPJ, are severely impaired in discriminating events across time in both visual fields [Battelli, L., Cavanagh, P., & Thornton, I. M. Perception of biological motion in parietal patients. Neuropsychologia, 41, 1808-1816, 2003]. One way to test this ability is to use a simultaneity judgment task, whereby participants are asked to indicate whether two events occurred simultaneously or not. We psychophysically varied the frequency rate of four flickering disks, and on most of the trials, one disk (either in the left or right visual field) was flickering out-of-phase relative to the others. We asked participants to report whether two left-or-right-presented disks were simultaneous or not. We tested a total of 23 right and left parietal lesion patients in Experiment 1, and only right parietal patients showed impairment in both visual fields while their low-level visual functions were normal. Importantly, to causally link the right TPJ to the relative timing processing, we ran a TMS experiment on healthy participants. Participants underwent three stimulation sessions and performed the same simultaneity judgment task before and after 20 min of low-frequency inhibitory TMS over right TPJ, left TPJ, or early visual area as a control. rTMS over the right TPJ caused a bilateral impairment in the simultaneity judgment task, whereas rTMS over left TPJ or over early visual area did not affect performance. Altogether, our results directly link the right TPJ to the processing of relative

  3. Distinguishing Intentions from Desires: Contributions of the Frontal and Parietal Lobes

    Science.gov (United States)

    Chiavarino, Claudia; Apperly, Ian A.; Humphreys, Glyn W.

    2010-01-01

    The ability to represent desires and intentions as two distinct mental states was investigated in patients with parietal (N = 8) and frontal (N = 6) lesions and in age-matched controls (N = 7). A task was used where the satisfaction of the desire and the fulfilment of the intention did not co-vary and were manipulated in a 2 x 2 set. In two…

  4. Pseudodisplacements of superior vena cava catheter in the persistent left superior vena cava

    Energy Technology Data Exchange (ETDEWEB)

    Jantsch, H.; Draxler, V.; Muhar, U.; Schlemmer, M.; Waneck, R.

    1983-01-01

    Pseudodisplacement of a left sided superior vena cava catheter in a persistent superior vena cava may be expected in adults in 0,37% and in a group of children with congenital heart disease in 2,5%. Embryology, anatomy and clinical implications is discussed on the basis of our own cases. The vena cava superior sinistra persitents is depending on a sufficient calibre a suitable vessel for a superior cava catheter.

  5. Fronto-parietal regulation of media violence exposure in adolescents: a multi-method study.

    Science.gov (United States)

    Strenziok, Maren; Krueger, Frank; Deshpande, Gopikrishna; Lenroot, Rhoshel K; van der Meer, Elke; Grafman, Jordan

    2011-10-01

    Adolescents spend a significant part of their leisure time watching TV programs and movies that portray violence. It is unknown, however, how the extent of violent media use and the severity of aggression displayed affect adolescents' brain function. We investigated skin conductance responses, brain activation and functional brain connectivity to media violence in healthy adolescents. In an event-related functional magnetic resonance imaging experiment, subjects repeatedly viewed normed videos that displayed different degrees of aggressive behavior. We found a downward linear adaptation in skin conductance responses with increasing aggression and desensitization towards more aggressive videos. Our results further revealed adaptation in a fronto-parietal network including the left lateral orbitofrontal cortex (lOFC), right precuneus and bilateral inferior parietal lobules, again showing downward linear adaptations and desensitization towards more aggressive videos. Granger causality mapping analyses revealed attenuation in the left lOFC, indicating that activation during viewing aggressive media is driven by input from parietal regions that decreased over time, for more aggressive videos. We conclude that aggressive media activates an emotion-attention network that has the capability to blunt emotional responses through reduced attention with repeated viewing of aggressive media contents, which may restrict the linking of the consequences of aggression with an emotional response, and therefore potentially promotes aggressive attitudes and behavior.

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

    Directory of Open Access Journals (Sweden)

    Michael T Lippert

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

  7. The parietal cortex in sensemaking: the dissociation of multiple types of spatial information.

    Science.gov (United States)

    Sun, Yanlong; Wang, Hongbin

    2013-01-01

    According to the data-frame theory, sensemaking is a macrocognitive process in which people try to make sense of or explain their observations by processing a number of explanatory structures called frames until the observations and frames become congruent. During the sensemaking process, the parietal cortex has been implicated in various cognitive tasks for the functions related to spatial and temporal information processing, mathematical thinking, and spatial attention. In particular, the parietal cortex plays important roles by extracting multiple representations of magnitudes at the early stages of perceptual analysis. By a series of neural network simulations, we demonstrate that the dissociation of different types of spatial information can start early with a rather similar structure (i.e., sensitivity on a common metric), but accurate representations require specific goal-directed top-down controls due to the interference in selective attention. Our results suggest that the roles of the parietal cortex rely on the hierarchical organization of multiple spatial representations and their interactions. The dissociation and interference between different types of spatial information are essentially the result of the competition at different levels of abstraction.

  8. Reduced oligodendroglial density in the inferior parietal lobule and lack of insight in schizophrenia

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    Victor M. Vostrikov

    2013-06-01

    Full Text Available Background and Objectives: Alterations and deficits of oligodendrocytes reported in the grey and white matter in schizophrenia may contribute to neuronal disconnectivity. Prefrontal-parietal functional disconnections have been implicated in diverse clinical symptoms of schizophrenia, including poor insight. We studied the effects of schizophrenia diagnosis and insight on numerical density (Nv of oligodendrocytes in the inferior parietal lobule (IPL. Methods: Nissl-stained sections from the Stanley "Parietal Collection" from male schizophrenia subjects (n = 24 having poor, fair, or good insight and healthy matched controls (n = 24 were examined. The Nv of oligodendrocytes was estimated in layer 3 of BA 39 and BA 40 of the IPL and in white matter underlying layer 6 by optical dissector method. Results: In BA 39 we found a significant 15% decrease in the Nv of oligodendrocytes in layer 3 in the schizophrenia group. Nv of oligodendrocytes in the poor+fair insight subgroup was 20% lower compared to controls (pR only in the control group. There were no significant group differences in the Nv of oligodendrocytes in BA 40 or in the white matter underlying BA 39/40 areas. Conclusions: Lack of insight in schizophrenia may be associated with a deficit of oligodendroglia in the grey matter of IPL.

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

    Science.gov (United States)

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

    2016-05-01

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

  10. The Parietal Cortex in Sensemaking: The Dissociation of Multiple Types of Spatial Information

    Directory of Open Access Journals (Sweden)

    Yanlong Sun

    2013-01-01

    Full Text Available According to the data-frame theory, sensemaking is a macrocognitive process in which people try to make sense of or explain their observations by processing a number of explanatory structures called frames until the observations and frames become congruent. During the sensemaking process, the parietal cortex has been implicated in various cognitive tasks for the functions related to spatial and temporal information processing, mathematical thinking, and spatial attention. In particular, the parietal cortex plays important roles by extracting multiple representations of magnitudes at the early stages of perceptual analysis. By a series of neural network simulations, we demonstrate that the dissociation of different types of spatial information can start early with a rather similar structure (i.e., sensitivity on a common metric, but accurate representations require specific goal-directed top-down controls due to the interference in selective attention. Our results suggest that the roles of the parietal cortex rely on the hierarchical organization of multiple spatial representations and their interactions. The dissociation and interference between different types of spatial information are essentially the result of the competition at different levels of abstraction.

  11. Acute parietal lobe infarction presenting as Gerstmann’s syndrome and cognitive decline mimicking senile dementia

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    Chen TY

    2013-07-01

    Full Text Available Tien-Yu Chen,1 Chun-Yen Chen,1,3 Che-Hung Yen,2,3 Shin-Chang Kuo,1,3 Yi-Wei Yeh,1,3 Serena Chang,1 San-Yuan Huang1,31Department of Psychiatry, 2Department of Neurology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, 3Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of ChinaAbstract: Gerstmann’s syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. An elderly man with a history of several cardiovascular diseases was initially brought to the psychiatric outpatient department by his family because of worsening of recent memory, executive function, and mixed anxious-depressive mood. Gerstmann’s syndrome without obvious motor function impairment and dementia-like features could be observed at first. Emergent brain computed tomography scan revealed new left-middle cerebral artery infarction over the left posterior parietal lobe. This case reminds us that acute cerebral infarction involving the parietal lobe may present as Gerstmann’s syndrome accompanied by cognitive decline mimicking dementia. As a result, emergent organic workups should be arranged, especially for elderly patients at high risk for cerebral vascular accident.Keywords: Gerstmann’s syndrome, dementia, parietal lobe infarction

  12. Top-down spatial categorization signal from prefrontal to posterior parietal cortex in the primate

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    Hugo eMerchant

    2011-08-01

    Full Text Available In the present study we characterized the strength and time course of category-selective responses in prefrontal cortex and area 7a of the posterior parietal cortex during a match-to-sample spatial categorization task. A monkey was trained to categorize whether the height of a horizontal sample bar, presented in rectangular frame at one of three vertical locations, was "high" or "low", depending on whether its position was above or below the frame’s midline. After the display of this sample bar, and after a delay, choice bars were sequentially flashed in two locations: at the top and at the bottom of the frame (‘choice’ epoch. If the monkey timed its response to the display of the choice bar that matched the sample bar, he was rewarded. We found that cells in prefrontal cortex discriminated category early after the initial sample bar was shown, and continued to differentiate up from down trials throughout the delay and choice periods. In contrast, parietal cells did not differentiate category until the choice period. Therefore, our results support the notion of a top-down categorical signal that originates in prefrontal cortex and that is only represented in parietal cortex when it is necessary to express the categorical decision through a movement.

  13. Parietal lobe deficits in frontotemporal lobar degeneration caused by a mutation in the progranulin gene.

    Science.gov (United States)

    Rohrer, Jonathan D; Warren, Jason D; Omar, Rohani; Mead, Simon; Beck, Jonathan; Revesz, Tamas; Holton, Janice; Stevens, John M; Al-Sarraj, Safa; Pickering-Brown, Stuart M; Hardy, John; Fox, Nick C; Collinge, John; Warrington, Elizabeth K; Rossor, Martin N

    2008-04-01

    To describe the clinical, neuropsychologic, and radiologic features of a family with a C31LfsX35 mutation in the progranulin gene CCDS11483.1). Case series. A large British kindred (DRC255) with a PGRN mutation was assessed. Affected individuals presented with a mean age of 57.8 years (range, 54-67 years) and a mean disease duration of 6.1 years (range, 2-11 years). All patients exhibited a clinical and radiologic phenotype compatible with frontotemporal lobar degeneration based on current consensus criteria. However, unlike sporadic frontotemporal lobar degeneration, parietal deficits, consisting of dyscalculia, visuoperceptual /visuospatial dysfunction, and/or limb apraxia, were a common feature, and brain imaging showed posterior extension of frontotemporal atrophy to involve the parietal lobes. Other common clinical features included language output impairment with either dynamic aphasia or nonfluent aphasia and a behavioral syndrome dominated by apathy. We suggest that parietal deficits may be a prominent feature of PGRN mutations and that these deficits may be caused by disruption of frontoparietal functional pathways.

  14. Effect of histamine on regional cerebral blood flow of the parietal lobe in rats.

    Science.gov (United States)

    Yang, Peng-Bo; Chen, Xin-Lin; Zhao, Jian-Jun; Zhang, Jian-Shui; Zhang, Jun-Feng; Tian, Yu-Mei; Liu, Yong

    2010-09-01

    Histamine is a powerful modulator that regulates blood vessels and blood flow. The effect of histamine on the extracortical vessels has been well described, while much less is known about the effect of histamine on intracortical vessels. In this study, we investigated the effect of histamine on regional cerebral blood flow in rat parietal lobe with laser Doppler flowmetry. The pharmacological characteristics of distinct ways (intracerebroventricular injection, intraperitoneal injection, and cranial window infusion) in applying histamine to the brain were also obtained and compared. Histamine applied in three ways all produced a decrease of rCBF in parietal lobe in a concentration-dependent manner. Cranial window infusion was the most effective way and intraperitoneal injection of L-histidine was the most ineffective, although it is a simple and applied way. To determine which type of receptor takes part in the vessel contraction induced by histamine, H1 receptor antagonist, diphenhydramine, and H2 receptor antagonist, cimetidine, were applied, respectively, before histamine administration. When the injection of cimetidine was conducted in advance, histamine still resulted in a decrease of infusion amount; while the injection of diphenhydramine was conducted in advance, the infusion of blood amount wasn't changed. These findings indicated that histamine could result in a reduction of rCBF in the rat parietal lobe and this effect of histamine may attribute partly to its combination with H1 receptor.

  15. Does a volume reduction of the parietal lobe contribute to freezing of gait in Parkinson's disease?

    Science.gov (United States)

    Rubino, Alfonso; Assogna, Francesca; Piras, Fabrizio; Di Battista, Maria Elena; Imperiale, Francesca; Chiapponi, Chiara; Spalletta, Gianfranco; Meco, Giuseppe

    2014-10-01

    Freezing of gait (FOG) is as a brief, episodic absence or marked reduction of forward progression of the feet despite the intention to walk. Structural neuroimaging studies on FOG in PD using volumetric techniques yielded variable and partially conflicting findings, probably reflecting the heterogeneity and complexity of the phenomenon. The aim of this study was to further explore the differences in local gray matter (GM) volume in patients with PD with and without FOG by using Voxel-Based Morphometry (VBM). We enrolled 26 patients (7 women and 19 men) with a diagnosis of PD in stable treatment with dopaminergic therapy. Thirteen patients classified as FOG+ were matched with thirteen non-freezer (FOG-) PD patients. All 26 participants underwent a detailed neuropsychological assessment as well as a VBM analysis derived from T1 weighted 3T MRI. The patient groups did not significantly differ for age, disease duration, H&Y stage, UPDRS part-III or educational attainment. No significant differences of cognitive profile emerged. PD-FOG+ patients showed a pattern of relative GM atrophy in left posterior parietal gyrus compared with PD-FOG-. Our results suggest that a specific pattern of cortical volume reduction involving posterior parietal cortex contributes to the occurrence of FOG in PD. These data agree with the growing body of evidence considering the parietal posterior cortex as an associative area involved in spatial control of motor behavior, par-taking in response selection to sensory evaluation. Copyright © 2014. Published by Elsevier Ltd.

  16. Drug-resistant parietal epilepsy: polymorphic ictal semiology does not preclude good post-surgical outcome.

    Science.gov (United States)

    Francione, Stefano; Liava, Alexandra; Mai, Roberto; Nobili, Lino; Sartori, Ivana; Tassi, Laura; Scarpa, Pina; Cardinale, Francesco; Castana, Laura; Cossu, Massimo; Lo Russo, Giorgio

    2015-03-01

    We investigated the anatomo-electro-clinical features and clinical outcome of surgical resections strictly confined to the parietal lobe in 40 consecutive patients who received surgery for pharmacoresistant seizures. The population was subcategorized into a paediatric (11 subjects; mean age at surgery: 7.2+/-3.7 years) and an adult group (29 patients; mean age at surgery: 30+/-10.8 years). The paediatric group more frequently exhibited personal antecedents, neurological impairment, high seizure frequency, and dysplastic lesions. Nonetheless, compared with adults, children had better outcome and more frequently reached definitive drug discontinuation after surgery. After a mean follow-up of 9.4 years (range: 3.1-16.7), 30 subjects (75%) were classified as Engel Class I. The presence of multiple types of aura in the same patient, as well as a high incidence of secondary generalization, represented a characteristic feature of parietal seizures and did not correlate negatively with surgical outcome. A total resection of the epileptogenic zone and a localizing/regional interictal EEG were statistically significant predictive factors of outcome. Intracerebral investigation, performed in 55% of cases, contributed to complete tailored resections of the epileptogenic area and determination of prognosis. Frequent subjective manifestations of parietal lobe seizures, such as vertiginous, cephalic and visual-moving sensations, underscore their potential misdiagnosis as non-epileptic events.

  17. Differential roles of the dorsal prefrontal and posterior parietal cortices in visual search: a TMS study.

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    Yan, Yulong; Wei, Rizhen; Zhang, Qian; Jin, Zhenlan; Li, Ling

    2016-07-25

    Although previous studies have shown that fronto-parietal attentional networks play a crucial role in bottom-up and top-down processes, the relative contribution of the frontal and parietal cortices to these processes remains elusive. Here we used transcranial magnetic stimulation (TMS) to interfere with the activity of the right dorsal prefrontal cortex (DLPFC) or the right posterior parietal cortex (PPC), immediately prior to the onset of the visual search display. Participants searched a target defined by color and orientation in "pop-out" or "search" condition. Repetitive TMS was applied to either the right DLPFC or the right PPC on different days. Performance was evaluated at baseline (no TMS), during TMS, and after TMS (Post-session). RTs were prolonged when TMS was applied over the DLPFC in the search, but not in the pop-out condition, relative to the baseline session. In comparison, TMS over the PPC prolonged RTs in the pop-out condition, and when the target appeared in the left visual field for the search condition. Taken together these findings provide evidence for a differential role of DLPFC and PPC in the visual search, indicating that DLPFC has a specific involvement in the "search" condition, while PPC is mainly involved in detecting "pop-out" targets.

  18. Altered Structural and Functional Connectivity in Late Preterm Preadolescence: An Anatomic Seed-Based Study of Resting State Networks Related to the Posteromedial and Lateral Parietal Cortex

    Science.gov (United States)

    Degnan, Andrew J.; Wisnowski, Jessica L.; Choi, SoYoung; Ceschin, Rafael; Bhushan, Chitresh; Leahy, Richard M.; Corby, Patricia; Schmithorst, Vincent J.; Panigrahy, Ashok

    2015-01-01

    Objective Late preterm birth confers increased risk of developmental delay, academic difficulties and social deficits. The late third trimester may represent a critical period of development of neural networks including the default mode network (DMN), which is essential to normal cognition. Our objective is to identify functional and structural connectivity differences in the posteromedial cortex related to late preterm birth. Methods Thirty-eight preadolescents (ages 9–13; 19 born in the late preterm period (≥32 weeks gestational age) and 19 at term) without access to advanced neonatal care were recruited from a low socioeconomic status community in Brazil. Participants underwent neurocognitive testing, 3-dimensional T1-weighted imaging, diffusion-weighted imaging and resting state functional MRI (RS-fMRI). Seed-based probabilistic diffusion tractography and RS-fMRI analyses were performed using unilateral seeds within the posterior DMN (posterior cingulate cortex, precuneus) and lateral parietal DMN (superior marginal and angular gyri). Results Late preterm children demonstrated increased functional connectivity within the posterior default mode networks and increased anti-correlation with the central-executive network when seeded from the posteromedial cortex (PMC). Key differences were demonstrated between PMC components with increased anti-correlation with the salience network seen only with posterior cingulate cortex seeding but not with precuneus seeding. Probabilistic tractography showed increased streamlines within the right inferior longitudinal fasciculus and inferior fronto-occipital fasciculus within late preterm children while decreased intrahemispheric streamlines were also observed. No significant differences in neurocognitive testing were demonstrated between groups. Conclusion Late preterm preadolescence is associated with altered functional connectivity from the PMC and lateral parietal cortex to known distributed functional cortical networks

  19. Altered Structural and Functional Connectivity in Late Preterm Preadolescence: An Anatomic Seed-Based Study of Resting State Networks Related to the Posteromedial and Lateral Parietal Cortex.

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    Andrew J Degnan

    Full Text Available Late preterm birth confers increased risk of developmental delay, academic difficulties and social deficits. The late third trimester may represent a critical period of development of neural networks including the default mode network (DMN, which is essential to normal cognition. Our objective is to identify functional and structural connectivity differences in the posteromedial cortex related to late preterm birth.Thirty-eight preadolescents (ages 9-13; 19 born in the late preterm period (≥32 weeks gestational age and 19 at term without access to advanced neonatal care were recruited from a low socioeconomic status community in Brazil. Participants underwent neurocognitive testing, 3-dimensional T1-weighted imaging, diffusion-weighted imaging and resting state functional MRI (RS-fMRI. Seed-based probabilistic diffusion tractography and RS-fMRI analyses were performed using unilateral seeds within the posterior DMN (posterior cingulate cortex, precuneus and lateral parietal DMN (superior marginal and angular gyri.Late preterm children demonstrated increased functional connectivity within the posterior default mode networks and increased anti-correlation with the central-executive network when seeded from the posteromedial cortex (PMC. Key differences were demonstrated between PMC components with increased anti-correlation with the salience network seen only with posterior cingulate cortex seeding but not with precuneus seeding. Probabilistic tractography showed increased streamlines within the right inferior longitudinal fasciculus and inferior fronto-occipital fasciculus within late preterm children while decreased intrahemispheric streamlines were also observed. No significant differences in neurocognitive testing were demonstrated between groups.Late preterm preadolescence is associated with altered functional connectivity from the PMC and lateral parietal cortex to known distributed functional cortical networks despite no significant

  20. Superiority in value and the repugnant conclusion

    DEFF Research Database (Denmark)

    Jensen, Karsten Klint

    2007-01-01

    James Griffin has considered a weak form of superiority in value a possible remedy to the Repugnant Conclusion. In this paper, I demonstrate that, in a context where value is additive, this weaker form collapses into a stronger form of superiority. And in a context where value is non-additive, weak...... superiority does not amount to a radical value difference at all. I then spell out the consequences of these results for different interpretations of Griffin's suggestion regarding population ethics. None of them comes out very successful, but perhaps they nevertheless retain some interest....

  1. El contexto del arte parietal. La tecnología de los artistas en la Cueva de Tito Bustillo (Asturias

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    Moure Romanillo, Alfonso

    1988-12-01

    Full Text Available This study overlaps in part with a communication presented to the «Colloque International d'Art Parietal Paléolithique» held at Perigueux-Le Thot in december 1984. The technological responses contained in a decorated zone of the cave of Tito Bustillo are analyzed, as well as the activities carried out on living floors related to the preparation and completion of the parietal art.

    El trabajo coincide parcialmente con la comunicación presentada al «Colloque International d'Art Parietal Paléolithique» celebrado en Perigueux-Le Thot, en diciembre de 1984. Se analizan las respuestas tecnológicas contenidas en un área de decoración de la cueva de Tito Bustillo (Asturias, así como las actividades en áreas de estancia relacionadas con la preparación y ejecución del arte parietal.

  2. [Changes in the ultrastructure of the stomach mucous membrane parietal cells caused by inhibitors of hydrochloric acid secretion].

    Science.gov (United States)

    Dondukova, G V; Morozov, I A

    2002-01-01

    The study of the action of phamotidine and omeprazol on the stomach parietal cells in patients with duodenal ulcer has shown that phamotidin results in changes of secretory membrane of the parietal cells increasing its secretory potential while omeprazol reduces energetic metabolism of the lining cell by the impact on its mitochondrial apparatus. Both in children and adults with duodenal ulcer more developed mitochondrial cell activity was found after omeprazol treatment.

  3. Inhibition of partially purified K+/H+-ATPase from guinea-pig isolated and enriched parietal cells by substituted benzimidazoles.

    OpenAIRE

    Beil, W.; Sewing, K F

    1984-01-01

    The cellular and subcellular distributions of adenosinetriphosphatases (ATPases) were examined in guinea-pig gastric mucosal cells. All cell types displayed Mg2+-ATPase and bicarbonate (HCO3-)-stimulated ATPase activity. K+-ATPase was located only in fractions derived from parietal cells. Differential and density-gradient centrifugation of material prepared from parietal cells revealed that K+-ATPase activity was located in a tubulo-vesicular membrane fraction. Enzyme activity was ten fold gr...

  4. Millian superiorities and the repugnant conclusion

    DEFF Research Database (Denmark)

    Jensen, Karsten Klint

    2008-01-01

    James Griffin has considered a form of superiority in value that is weaker than lexical priority as a possible remedy to the Repugnant Conclusion. In this article, I demonstrate that, in a context where value is additive, this weaker form collapses into the stronger form of superiority. And in a ......James Griffin has considered a form of superiority in value that is weaker than lexical priority as a possible remedy to the Repugnant Conclusion. In this article, I demonstrate that, in a context where value is additive, this weaker form collapses into the stronger form of superiority...... of these results for different interpretations of Griffin's suggestion regarding population ethics. None of them comes out very successful, but perhaps they nevertheless retain some interest....

  5. Measuring Financial Gains from Genetically Superior Trees

    Science.gov (United States)

    George Dutrow; Clark Row

    1976-01-01

    Planting genetically superior loblolly pines will probably yield high profits.Forest economists have made computer simulations that predict financial gains expected from a tree improvement program under actual field conditions.

  6. Superior mesenteric artery syndrome causing growth retardation

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    Halil İbrahim Taşcı

    2013-03-01

    Full Text Available Superior mesenteric artery syndrome is a rare and lifethreateningclinical condition caused by the compressionof the third portion of the duodenum between the aortaand the superior mesenteric artery’s proximal part. Thiscompression may lead to chronic intermittent, acute totalor partial obstruction. Sudden weight-loss and the relateddecrease in the fat tissue are considered to be the etiologicalreason of acute stenosis. Weight-loss accompaniedby nausea, vomiting, anorexia, epigastric pain, andbloating are the leading complaints. Barium radiographs,computerized tomography, conventional angiography,tomographic and magnetic resonance angiography areused in the diagnosis. There are medical and surgical approachesto treatment. We hereby present the case ofa patient with superior mesenteric artery syndrome withdelayed diagnosis.Key words: superior mesenteric artery syndrome, nausea-vomiting, anorexia

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

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    Xiu-Jie Wu

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

  8. Leiomyosarcoma of the superior vena cava.

    Science.gov (United States)

    de Chaumont, Arthus; Pierret, Charles; de Kerangal, Xavier; Le Moulec, Sylvestre; Laborde, François

    2014-08-01

    Leiomyosarcoma of the superior vena cava is a very rare tumor and only a few cases have been reported, with various techniques of vascular reconstruction. We describe a new case of leiomyosarcoma of the superior vena cava in a 61-year-old woman with extension to the brachiocephalic arterial trunk. Resection and vascular reconstruction were performed using, respectively, polytetrafluoroethylene and polyethylene terephtalate vascular grafts.

  9. Superior mesenteric artery compression syndrome - case report

    OpenAIRE

    Paulo Rocha França Neto; Rodrigo de Almeida Paiva; Antônio Lacerda Filho; Fábio Lopes de Queiroz; Teon Noronha

    2011-01-01

    Superior mesenteric artery syndrome is an entity generally caused by the loss of the intervening mesenteric fat pad, resulting in compression of the third portion of the duodenum by the superior mesenteric artery. This article reports the case of a patient with irremovable metastatic adenocarcinoma in the sigmoid colon, that evolved with intense vomiting. Intestinal transit was carried out, which showed important gastric dilation extended until the third portion of the duodenum, compatible wi...

  10. Superior oblique surgery: when and how?

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    Taylan Şekeroğlu H

    2013-08-01

    Full Text Available Hande Taylan Şekeroğlu,1 Ali Sefik Sanac,1 Umut Arslan,2 Emin Cumhur Sener11Department of Ophthalmology, 2Department of Biostatistics, Hacettepe University Faculty of Medicine, Ankara, TurkeyBackground: The purpose of this paper is to review different types of superior oblique muscle surgeries, to describe the main areas in clinical practice where superior oblique surgery is required or preferred, and to discuss the preferred types of superior oblique surgery with respect to their clinical outcomes.Methods: A consecutive nonrandomized retrospective series of patients who had undergone superior oblique muscle surgery as a single procedure were enrolled in the study. The diagnosis, clinical features, preoperative and postoperative vertical deviations in primary position, type of surgery, complications, and clinical outcomes were reviewed. The primary outcome measures were the type of strabismus and the type of superior oblique muscle surgery. The secondary outcome measure was the results of the surgeries.Results: The review identified 40 (20 male, 20 female patients with a median age of 6 (2–45 years. Nineteen patients (47.5% had Brown syndrome, eleven (27.5% had fourth nerve palsy, and ten (25.0% had horizontal deviations with A pattern. The most commonly performed surgery was superior oblique tenotomy in 29 (72.5% patients followed by superior oblique tuck in eleven (27.5% patients. The amount of vertical deviation in the fourth nerve palsy and Brown syndrome groups (P = 0.01 for both and the amount of A pattern in the A pattern group were significantly reduced postoperatively (P = 0.02.Conclusion: Surgery for the superior oblique muscle requires experience and appropriate preoperative evaluation in view of its challenging nature. The main indications are Brown syndrome, fourth nerve palsy, and A pattern deviations. Superior oblique surgery may be effective in terms of pattern collapse and correction of vertical deviations in primary

  11. 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

  12. The left inferior parietal lobe represents stored hand-postures for object use and action prediction.

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    van Elk, Michiel

    2014-01-01

    Action semantics enables us to plan actions with objects and to predict others' object-directed actions as well. Previous studies have suggested that action semantics are represented in a fronto-parietal action network that has also been implicated to play a role in action observation. In the present fMRI study it was investigated how activity within this network changes as a function of the predictability of an action involving multiple objects and requiring the use of action semantics. Participants performed an action prediction task in which they were required to anticipate the use of a centrally presented object that could be moved to an associated target object (e.g., hammer-nail). The availability of actor information (i.e., presenting a hand grasping the central object) and the number of possible target objects (i.e., 0, 1, or 2 target objects) were independently manipulated, resulting in different levels of predictability. It was found that making an action prediction based on actor information resulted in an increased activation in the extrastriate body area (EBA) and the fronto-parietal action observation network (AON). Predicting actions involving a target object resulted in increased activation in the bilateral IPL and frontal motor areas. Within the AON, activity in the left inferior parietal lobe (IPL) and the left premotor cortex (PMC) increased as a function of the level of action predictability. Together these findings suggest that the left IPL represents stored hand-postures that can be used for planning object-directed actions and for predicting other's actions as well.

  13. Neuronal chains for actions in the parietal lobe: a computational model.

    Directory of Open Access Journals (Sweden)

    Fabian Chersi

    Full Text Available The inferior part of the parietal lobe (IPL is known to play a very important role in sensorimotor integration. Neurons in this region code goal-related motor acts performed with the mouth, with the hand and with the arm. It has been demonstrated that most IPL motor neurons coding a specific motor act (e.g., grasping show markedly different activation patterns according to the final goal of the action sequence in which the act is embedded (grasping for eating or grasping for placing. Some of these neurons (parietal mirror neurons show a similar selectivity also during the observation of the same action sequences when executed by others. Thus, it appears that the neuronal response occurring during the execution and the observation of a specific grasping act codes not only the executed motor act, but also the agent's final goal (intention.In this work we present a biologically inspired neural network architecture that models mechanisms of motor sequences execution and recognition. In this network, pools composed of motor and mirror neurons that encode motor acts of a sequence are arranged in form of action goal-specific neuronal chains. The execution and the recognition of actions is achieved through the propagation of activity bursts along specific chains modulated by visual and somatosensory inputs.The implemented spiking neuron network is able to reproduce the results found in neurophysiological recordings of parietal neurons during task performance and provides a biologically plausible implementation of the action selection and recognition process.Finally, the present paper proposes a mechanism for the formation of new neural chains by linking together in a sequential manner neurons that represent subsequent motor acts, thus producing goal-directed sequences.

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

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    Johanna eWagner

    2014-02-01

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

  15. 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.

  16. Psychic Tonus, Body Schema and the Parietal Lobes: A Multiple Lesion Case Analysis

    OpenAIRE

    C. M. J. Braun; Desjardins, S.; Gaudelet, S.; Guimond, A.

    2007-01-01

    The psychic tonus model (Braun and colleagues, 1999, 2002, 2003, 2006) states that the left hemisphere is a “booster” of internal experience and behavior in general, and that the right hemisphere is a “dampener”. Twenty-five patients with a “positive” extreme disturbance of body schema (somatoparaphrenia) and 37 patients with a “negative” disturbance of body schema (autotopagnosia or Gerstmann’s syndrome), all following a unilateral parietal lesion, were found in the literature and were analy...

  17. Attention to Multiple Objects Facilitates Their Integration in Prefrontal and Parietal Cortex.

    Science.gov (United States)

    Kim, Yee-Joon; Tsai, Jeffrey J; Ojemann, Jeffrey; Verghese, Preeti

    2017-05-10

    Selective attention is known to interact with perceptual organization. In visual scenes, individual objects that are distinct and discriminable may occur on their own, or in groups such as a stack of books. The main objective of this study is to probe the neural interaction that occurs between individual objects when attention is directed toward one or more objects. Here we record steady-state visual evoked potentials via electrocorticography to directly assess the responses to individual stimuli and to their interaction. When human participants attend to two adjacent stimuli, prefrontal and parietal cortex shows a selective enhancement of only the neural interaction between stimuli, but not the responses to individual stimuli. When only one stimulus is attended, the neural response to that stimulus is selectively enhanced in prefrontal and parietal cortex. In contrast, early visual areas generally manifest responses to individual stimuli and to their interaction regardless of attentional task, although a subset of the responses is modulated similarly to prefrontal and parietal cortex. Thus, the neural representation of the visual scene as one progresses up the cortical hierarchy becomes more highly task-specific and represents either individual stimuli or their interaction, depending on the behavioral goal. Attention to multiple objects facilitates an integration of objects akin to perceptual grouping.SIGNIFICANCE STATEMENT Individual objects in a visual scene are seen as distinct entities or as parts of a whole. Here we examine how attention to multiple objects affects their neural representation. Previous studies measured single-cell or fMRI responses and obtained only aggregate measures that combined the activity to individual stimuli as well as their potential interaction. Here, we directly measure electrocorticographic steady-state responses corresponding to individual objects and to their interaction using a frequency-tagging technique. Attention to two

  18. Study of the paleolithic parietal art from the archaeological perspective: old ghosts / new approaches

    Directory of Open Access Journals (Sweden)

    Clara Hernando Álvarez

    2010-03-01

    Full Text Available This paper aims to analyse the parietal palaeolithic graphic designs from an archaeological perspective, leaving aside the aesthetic ties of traditional historiography. Traditional European analysis techniques of palaeolithic rock art will be contrasted with new interdisciplinary applications, looking for an archaeological knowledge about the artistic graphic expression of prehistoric societies. Finally, a methodological trial will be suggestedapplying the Harris Matrix in the reading and arrangement (ordination of the palaeolithic graphic designs of the central panel of Llonin's cave (Peñamellera Alta, Asturias.

  19. A single aspergillus fumigatus intracranial abscess in an immunocompetent patient with parietal lobe tumorectomy.

    Science.gov (United States)

    Bao, Zhao-Shi; You, Gan; Li, Wen-Bin; Jiang, Tao

    2014-06-07

    Aspergillosis of the central nervous system is a rare fungal infection that is mainly reported in patients with immune deficiency, such as AIDS patients and organ transplant patients treated with immunosuppressive agents, and is uncommon among patients with intact immune function. We report here a rare case of intracranial aspergillosis in a patient who had previously undergone a parietal lobe tumorectomy. Aspergillus fumigatus was confirmed by histopathology, and susceptibility tests reported that this infection should respond to voriconazole. We believe the immunosuppression resulting from surgical trauma and glucocorticosteroid treatment may be contributing to the infection, and therefore management of these two factors may improve the prognosis.

  20. Gastrin induces parathyroid hormone-like hormone expression in gastric parietal cells.

    Science.gov (United States)

    Al Menhali, Asma; Keeley, Theresa M; Demitrack, Elise S; Samuelson, Linda C

    2017-06-01

    Parietal cells play a fundamental role in stomach maintenance, not only by creating a pathogen-free environment through the production of gastric acid, but also by secreting growth factors important for homeostasis of the gastric epithelium. The gastrointestinal hormone gastrin is known to be a central regulator of both parietal cell function and gastric epithelial cell proliferation and differentiation. Our previous gene expression profiling studies of mouse stomach identified parathyroid hormone-like hormone (PTHLH) as a potential gastrin-regulated gastric growth factor. Although PTHLH is commonly overexpressed in gastric tumors, its normal expression, function, and regulation in the stomach are poorly understood. In this study we used pharmacologic and genetic mouse models as well as human gastric cancer cell lines to determine the cellular localization and regulation of this growth factor by the hormone gastrin. Analysis of Pthlh(LacZ/+) knock-in reporter mice localized Pthlh expression to parietal cells in the gastric corpus. Regulation by gastrin was demonstrated by increased Pthlh mRNA abundance after acute gastrin treatment in wild-type mice and reduced expression in gastrin-deficient mice. PTHLH transcripts were also observed in normal human stomach as well as in human gastric cancer cell lines. Gastrin treatment of AGS-E gastric cancer cells induced a rapid and robust increase in numerous PTHLH mRNA isoforms. This induction was largely due to increased transcriptional initiation, although analysis of mRNA half-life showed that gastrin treatment also extended the half-life of PTHLH mRNA, suggesting that gastrin regulates expression by both transcriptional and posttranscriptional mechanisms.NEW & NOTEWORTHY We show that the growth factor parathyroid hormone-like hormone (PTHLH) is expressed in acid-secreting parietal cells of the mouse stomach. We define the specific PTHLH mRNA isoforms expressed in human stomach and in human gastric cancer cell lines and

  1. Whisker-related afferents in superior colliculus.

    Science.gov (United States)

    Castro-Alamancos, Manuel A; Favero, Morgana

    2016-05-01

    Rodents use their whiskers to explore the environment, and the superior colliculus is part of the neural circuits that process this sensorimotor information. Cells in the intermediate layers of the superior colliculus integrate trigeminotectal afferents from trigeminal complex and corticotectal afferents from barrel cortex. Using histological methods in mice, we found that trigeminotectal and corticotectal synapses overlap somewhat as they innervate the lower and upper portions of the intermediate granular layer, respectively. Using electrophysiological recordings and optogenetics in anesthetized mice in vivo, we showed that, similar to rats, whisker deflections produce two successive responses that are driven by trigeminotectal and corticotectal afferents. We then employed in vivo and slice experiments to characterize the response properties of these afferents. In vivo, corticotectal responses triggered by electrical stimulation of the barrel cortex evoke activity in the superior colliculus that increases with stimulus intensity and depresses with increasing frequency. In slices from adult mice, optogenetic activation of channelrhodopsin-expressing trigeminotectal and corticotectal fibers revealed that cells in the intermediate layers receive more efficacious trigeminotectal, than corticotectal, synaptic inputs. Moreover, the efficacy of trigeminotectal inputs depresses more strongly with increasing frequency than that of corticotectal inputs. The intermediate layers of superior colliculus appear to be tuned to process strong but infrequent trigeminal inputs and weak but more persistent cortical inputs, which explains features of sensory responsiveness, such as the robust rapid sensory adaptation of whisker responses in the superior colliculus. Copyright © 2016 the American Physiological Society.

  2. Designing functionally graded materials with superior load-bearing properties.

    Science.gov (United States)

    Zhang, Yu; Sun, Ming-Jie; Zhang, Denzil

    2012-03-01

    Ceramic prostheses often fail from fracture and wear. We hypothesize that these failures may be substantially mitigated by an appropriate grading of elastic modulus at the ceramic surface. In this study, we elucidate the effect of elastic modulus profile on the flexural damage resistance of functionally graded materials (FGMs), providing theoretical guidelines for designing FGMs with superior load-bearing property. The Young's modulus of the graded structure is assumed to vary in a power-law relation with a scaling exponent n; this is in accordance with experimental observations from our laboratory and elsewhere. Based on the theory for bending of graded beams, we examine the effect of n value and bulk-to-surface modulus ratio (E(b)/E(s)) on stress distribution through the graded layer. Theory predicts that a low exponent (0.15graded materials with various n values and E(b)/E(s) ratios can be fabricated by infiltrating alumina and zirconia with a low-modulus glass. Flexural tests show that graded alumina and zirconia with suitable values of these parameters exhibit superior load-bearing capacity, 20-50% higher than their homogeneous counterparts. Improving load-bearing capacity of ceramic materials could have broad impacts on biomedical, civil, structural, and an array of other engineering applications.

  3. Sense of agency is related to gamma band coupling in an inferior parietal-preSMA circuitry

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    Anina eRitterband-Rosenbaum

    2014-07-01

    Full Text Available In the present study we tested whether sense of agency (SoA is reflected by changes in coupling between right medio-frontal/supplementary motor area (SMA and inferior parietal cortex (IPC. Twelve healthy adult volunteers participated in the study. They performed a variation of a line-drawing task (Nielsen, 1963;Fourneret and Jeannerod, 1998, in which they moved a cursor on a digital tablet with their right hand without seeing the hand. Visual feedback displayed on a computer monitor was either in correspondence with or deviated from the actual movement. This made participants uncertain as to the agent of the movement and they reported SoA in approximately 50% of trials when the movement was computer-generated. We tested whether IPC-preSMA coupling was associated with SoA, using dynamic causal modelling (DCM for induced responses (Chen et al., 2008;Herz et al., 2012. Nine different DCMs were constructed for the early and late phases of the task, respectively. All models included two regions: a superior medial gyrus (preSMA region and a right supramarginal gyrus (IPC region. Bayesian models selection (Stephan et al., 2009 favoured a model with input to IPC and modulation of the forward connection to SMA in the late task phase, and a model with input to preSMA and modulation of the backward connection was favoured for the early task phase. The analysis shows that IPC source activity in the 50-60Hz range modulated preSMA source activity in the 40-70 Hz range in the presence of SoA compared with no SoA in the late task phase, but the test of the early task phase did not reveal any differences between presence and absence of SoA. We show that SoA is associated with a directionally specific between frequencies coupling from IPC to preSMA in the higher gamma (ɣ band in the late task phase. This suggests that SoA is a retrospective perception, which is highly dependent on interpretation of the outcome of the performed action.

  4. Neural correlates of conflict between gestures and words: A domain-specific role for a temporal-parietal complex

    Science.gov (United States)

    Noah, J. Adam; Dravida, Swethasri; Zhang, Xian; Yahil, Shaul; Hirsch, Joy

    2017-01-01

    The interpretation of social cues is a fundamental function of human social behavior, and resolution of inconsistencies between spoken and gestural cues plays an important role in successful interactions. To gain insight into these underlying neural processes, we compared neural responses in a traditional color/word conflict task and to a gesture/word conflict task to test hypotheses of domain-general and domain-specific conflict resolution. In the gesture task, recorded spoken words (“yes” and “no”) were presented simultaneously with video recordings of actors performing one of the following affirmative or negative gestures: thumbs up, thumbs down, head nodding (up and down), or head shaking (side-to-side), thereby generating congruent and incongruent communication stimuli between gesture and words. Participants identified the communicative intent of the gestures as either positive or negative. In the color task, participants were presented the words “red” and “green” in either red or green font and were asked to identify the color of the letters. We observed a classic “Stroop” behavioral interference effect, with participants showing increased response time for incongruent trials relative to congruent ones for both the gesture and color tasks. Hemodynamic signals acquired using functional near-infrared spectroscopy (fNIRS) were increased in the right dorsolateral prefrontal cortex (DLPFC) for incongruent trials relative to congruent trials for both tasks consistent with a common, domain-general mechanism for detecting conflict. However, activity in the left DLPFC and frontal eye fields and the right temporal-parietal junction (TPJ), superior temporal gyrus (STG), supramarginal gyrus (SMG), and primary and auditory association cortices was greater for the gesture task than the color task. Thus, in addition to domain-general conflict processing mechanisms, as suggested by common engagement of right DLPFC, socially specialized neural modules

  5. Superior-subordinate relations as organizational processes

    DEFF Research Database (Denmark)

    Asmuss, Birte; Aggerholm, Helle Kryger; Oshima, Sae

    Since the emergence of the practice turn in social sciences (Golsorkhi et al. 2010), studies have shown a number of institutionally relevant aspects as achievements across time and by means of various resources (human and non-human) (Taylor & van Every 2000, Cooren et al. 2006). Such a process view...... on organizational practices relates closely to an increased focus on communication as being constitutive of the organization in general and the superior-subordinate relationship in specific. The current study aims to contribute to this line of research by investigating micro-practices involved in establishing...... superior-subordinate relations in a specific institutionalized setting: performance appraisal interviews (PAIs). While one main task of PAIs is to manage and integrate organizational and employee performance (Fletcher, 2001:473), PAIs are also organizational practices where superior-subordinate relations...

  6. Lake Superior Aquatic Invasive Species Complete Prevention Plan

    Science.gov (United States)

    The Lake Superior Aquatic Invasive Species Complete Prevention Plan is an expression of the best professional judgment of the members of the Lake Superior Task Force as to what is necessary to protect Lake Superior from new aquatic invasive species.

  7. Endovascular treatment of superior vena cava syndrome

    DEFF Research Database (Denmark)

    Duvnjak, Stevo; Andersen, Poul Erik

    2011-01-01

    Abstract AIM: The aim of this study was to report our experience with palliative stent treatment of superior vena cava syndrome. METHODS: Between January 2008 and December 2009, 30 patients (mean age 60.7 years) were treated with stents because of stenosed superior vena cava. All patients presented...... there was an immediate clinical improvement with considerable reduction in the edema of upper extremities and head. There was, however, continous dyspnea in five patients (17%) and two patients (7%) had persistent visible collateral venous circulations on the upper chest. There were no stent associated complications...

  8. EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing.

    Directory of Open Access Journals (Sweden)

    Michael X Cohen

    Full Text Available Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus conflict modulation in stimulus-contralateral parietal gamma (30-50 Hz, followed by a later alpha-band (8-12 Hz conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4-8 Hz, alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions.

  9. EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing.

    Science.gov (United States)

    Cohen, Michael X; Ridderinkhof, K Richard

    2013-01-01

    Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus) conflict modulation in stimulus-contralateral parietal gamma (30-50 Hz), followed by a later alpha-band (8-12 Hz) conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4-8 Hz), alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials) had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions.

  10. Psychic Tonus, Body Schema and the Parietal Lobes: A Multiple Lesion Case Analysis

    Directory of Open Access Journals (Sweden)

    C. M. J. Braun

    2007-01-01

    Full Text Available The psychic tonus model (Braun and colleagues, 1999, 2002, 2003, 2006 states that the left hemisphere is a “booster” of internal experience and behavior in general, and that the right hemisphere is a “dampener”. Twenty-five patients with a “positive” extreme disturbance of body schema (somatoparaphrenia and 37 patients with a “negative” disturbance of body schema (autotopagnosia or Gerstmann’s syndrome, all following a unilateral parietal lesion, were found in the literature and were analyzed to test predictions from Braun’s “psychic tonus” model. As expected, patients with a positive syndrome had a right hemisphere lesion significantly more frequently, and those with a negative syndrome had a left hemisphere lesion significantly more frequently. Thus the psychic tonus model of hemispheric specialization, previously supported with regard to psychomotor baseline, libido, talkativeness, memory, auditory and visual perceptual tonus, now incorporates the tonus of representation of the body (body schema in the parietal lobes.

  11. Prefrontal and parietal cortex in human episodic memory: an interference study by repetitive transcranial magnetic stimulation.

    Science.gov (United States)

    Rossi, Simone; Pasqualetti, Patrizio; Zito, Giancarlo; Vecchio, Fabrizio; Cappa, Stefano F; Miniussi, Carlo; Babiloni, Claudio; Rossini, Paolo M

    2006-02-01

    Neuroimaging findings, including repetitive transcranial magnetic stimulation (rTMS) interference, point to an engagement of prefrontal cortex (PFC) in learning and memory. Whether parietal cortex (PC) activity is causally linked to successful episodic encoding and retrieval is still uncertain. We compared the effects of event-related active or sham rTMS (a rapid-rate train coincident to the very first phases of memoranda presentation) to the left or right intraparietal sulcus, during a standardized episodic memory task of visual scenes, with those obtained in a fully matched sample of subjects who received rTMS on left or right dorsolateral PFC during the same task. In these subjects, specific hemispheric effects of rTMS included interference with encoding after left stimulation and disruption of retrieval after right stimulation. The interference of PC-rTMS on encoding/retrieval performance was negligible, lacking specificity even when higher intensities of stimulation were applied. However, right PC-rTMS of the same intensity lengthened reaction times in the context of a purely attentive visuospatial task. These results suggest that the activity of intraparietal sulci shown in several functional magnetic resonance studies on memory, unlike that of the dorsolateral PFC, is not causally engaged to a useful degree in memory encoding and retrieval of visual scenes. The parietal activations accompanying the memorization processes could reflect the engagement of a widespread brain attentional network, in which interference on a single 'node' is insufficient for an overt disruption of memory performance.

  12. Early Left Parietal Activity Elicited by Direct Gaze: A High-Density EEG Study

    Science.gov (United States)

    Burra, Nicolas; Kerzel, Dirk; George, Nathalie

    2016-01-01

    Gaze is one of the most important cues for human communication and social interaction. In particular, gaze contact is the most primary form of social contact and it is thought to capture attention. A very early-differentiated brain response to direct versus averted gaze has been hypothesized. Here, we used high-density electroencephalography to test this hypothesis. Topographical analysis allowed us to uncover a very early topographic modulation (40–80 ms) of event-related responses to faces with direct as compared to averted gaze. This modulation was obtained only in the condition where intact broadband faces–as opposed to high-pass or low-pas filtered faces–were presented. Source estimation indicated that this early modulation involved the posterior parietal region, encompassing the left precuneus and inferior parietal lobule. This supports the idea that it reflected an early orienting response to direct versus averted gaze. Accordingly, in a follow-up behavioural experiment, we found faster response times to the direct gaze than to the averted gaze broadband faces. In addition, classical evoked potential analysis showed that the N170 peak amplitude was larger for averted gaze than for direct gaze. Taken together, these results suggest that direct gaze may be detected at a very early processing stage, involving a parallel route to the ventral occipito-temporal route of face perceptual analysis. PMID:27880776

  13. Posterior Parietal Cortex Drives Inferotemporal Activations During Three-Dimensional Object Vision.

    Directory of Open Access Journals (Sweden)

    Ilse C Van Dromme

    2016-04-01

    Full Text Available The primate visual system consists of a ventral stream, specialized for object recognition, and a dorsal visual stream, which is crucial for spatial vision and actions. However, little is known about the interactions and information flow between these two streams. We investigated these interactions within the network processing three-dimensional (3D object information, comprising both the dorsal and ventral stream. Reversible inactivation of the macaque caudal intraparietal area (CIP during functional magnetic resonance imaging (fMRI reduced fMRI activations in posterior parietal cortex in the dorsal stream and, surprisingly, also in the inferotemporal cortex (ITC in the ventral visual stream. Moreover, CIP inactivation caused a perceptual deficit in a depth-structure categorization task. CIP-microstimulation during fMRI further suggests that CIP projects via posterior parietal areas to the ITC in the ventral stream. To our knowledge, these results provide the first causal evidence for the flow of visual 3D information from the dorsal stream to the ventral stream, and identify CIP as a key area for depth-structure processing. Thus, combining reversible inactivation and electrical microstimulation during fMRI provides a detailed view of the functional interactions between the two visual processing streams.

  14. Sensorimotor experience and verb-category mapping in human sensory, motor and parietal neurons.

    Science.gov (United States)

    Yang, Ying; Dickey, Michael Walsh; Fiez, Julie; Murphy, Brian; Mitchell, Tom; Collinger, Jennifer; Tyler-Kabara, Elizabeth; Boninger, Michael; Wang, Wei

    2017-07-01

    Semantic grounding is the process of relating meaning to symbols (e.g., words). It is the foundation for creating a representational symbolic system such as language. Semantic grounding for verb meaning is hypothesized to be achieved through two mechanisms: sensorimotor mapping, i.e., directly encoding the sensorimotor experiences the verb describes, and verb-category mapping, i.e., encoding the abstract category a verb belongs to. These two mechanisms were investigated by examining neuronal-level spike (i.e. neuronal action potential) activities from the motor, somatosensory and parietal areas in two human participants. Motor and a portion of somatosensory neurons were found to be involved in primarily sensorimotor mapping, while parietal and some somatosensory neurons were found to be involved in both sensorimotor and verb-category mapping. The time course of the spike activities and the selective tuning pattern of these neurons indicate that they belong to a large neural network used for semantic processing. This study is the first step towards understanding how words are processed by neurons. Published by Elsevier Ltd.

  15. Intentional signals during saccadic and reaching delays in the human posterior parietal cortex.

    Science.gov (United States)

    Galati, Gaspare; Committeri, Giorgia; Pitzalis, Sabrina; Pelle, Gina; Patria, Fabiana; Fattori, Patrizia; Galletti, Claudio

    2011-12-01

    In the monkey posterior parietal cortex (PPC), there is clear evidence of anatomically segregated neuronal populations specialized for planning saccades and arm-reaching movements. However, functional neuroimaging studies in humans have yielded controversial results. Here we show that the human PPC contains distinct subregions responsive to salient visual cues, some of which combine spatial and action-related signals into 'intentional' signals. Participants underwent event-related functional magnetic resonance imaging while performing delayed saccades and long-range arm reaches instructed by visual cues. We focused on activity in the time period following the cue and preceding the actual movement. The use of individual cortical surface reconstructions with detailed sulcal labeling allowed the definition of six responsive regions with distinctive anatomical locations in the PPC. Each region exhibited a distinctive combination of transient and sustained signals during the delay, modulated by either the cue spatial location (contralateral vs. ipsilateral), the instructed action (saccades vs. reaching) or both. Importantly, a lateral and a medial dorsal parietal region showed sustained responses during the delay preferentially for contralateral saccadic and reaching trials, respectively. In the lateral region, preference for saccades was evident only as a more sustained response during saccadic vs. reaching delays, whereas the medial region also showed a higher transient response to cues signaling reaching vs. saccadic actions. These response profiles closely match the behavior of neurons in the macaque lateral and medial intraparietal area, respectively, and suggest that these corresponding human regions are encoding spatially directed action plans or 'intentions'.

  16. Timing of spatial priming within the fronto-parietal attention network: A TMS study.

    Science.gov (United States)

    Kehrer, Stefanie; Kraft, Antje; Koch, Stefan P; Kathmann, Norbert; Irlbacher, Kerstin; Brandt, Stephan A

    2015-07-01

    The posterior parietal cortex (PPC) and the dorsolateral prefrontal cortex (DLPFC) are known to be part of a cortical network involved in visual spatial attention. Top-down control can modulate processing at target and distractor positions over a sequence of trials, leading to positive priming at prior target positions and negative priming at prior distractor positions. In order to elucidate the exact time course of this top-down mechanism we here propose a transcranial magnetic stimulation (TMS) protocol. Single-pulses were applied over the right PPC, the right DLPFC or over the vertex (sham stimulation) at five time intervals (50, 100, 150, 200, 250 ms) after onset of a probe display during a spatial negative priming paradigm. Both suppression of the negative priming effect at a previous distractor position and enhancement of positive priming at a previous target position was found if a TMS pulse was applied 100 ms after the probe display onset either over the right DLPFC or the right PPC. We suggest that top-down mechanisms within the right fronto-parietal attention network are compromised during TMS interference in this time window.

  17. Object integration requires attention: Visual search for Kanizsa figures in parietal extinction.

    Science.gov (United States)

    Gögler, Nadine; Finke, Kathrin; Keller, Ingo; Müller, Hermann J; Conci, Markus

    2016-11-01

    The contribution of selective attention to object integration is a topic of debate: integration of parts into coherent wholes, such as in Kanizsa figures, is thought to arise either from pre-attentive, automatic coding processes or from higher-order processes involving selective attention. Previous studies have attempted to examine the role of selective attention in object integration either by employing visual search paradigms or by studying patients with unilateral deficits in selective attention. Here, we combined these two approaches to investigate object integration in visual search in a group of five patients with left-sided parietal extinction. Our search paradigm was designed to assess the effect of left- and right-grouped nontargets on detecting a Kanizsa target square. The results revealed comparable reaction time (RT) performance in patients and controls when they were presented with displays consisting of a single to-be-grouped item that had to be classified as target vs. nontarget. However, when display size increased to two items, patients showed an extinction-specific pattern of enhanced RT costs for nontargets that induced a partial shape grouping on the right, i.e., in the attended hemifield (relative to the ungrouped baseline). Together, these findings demonstrate a competitive advantage for right-grouped objects, which in turn indicates that in parietal extinction, attentional competition between objects particularly limits integration processes in the contralesional, i.e., left hemifield. These findings imply a crucial contribution of selective attentional resources to visual object integration.

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

    Science.gov (United States)

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

    2012-09-01

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

  19. fMRI adaptation reveals mirror neurons in human inferior parietal cortex.

    Science.gov (United States)

    Chong, Trevor T-J; Cunnington, Ross; Williams, Mark A; Kanwisher, Nancy; Mattingley, Jason B

    2008-10-28

    Mirror neurons, as originally described in the macaque, have two defining properties [1, 2]: They respond specifically to a particular action (e.g., bringing an object to the mouth), and they produce their action-specific responses independent of whether the monkey executes the action or passively observes a conspecific performing the same action. In humans, action observation and action execution engage a network of frontal, parietal, and temporal areas. However, it is unclear whether these responses reflect the activity of a single population that represents both observed and executed actions in a common neural code or the activity of distinct but overlapping populations of exclusively perceptual and motor neurons [3]. Here, we used fMRI adaptation to show that the right inferior parietal lobe (IPL) responds independently to specific actions regardless of whether they are observed or executed. Specifically, responses in the right IPL were attenuated when participants observed a recently executed action relative to one that had not previously been performed. This adaptation across action and perception demonstrates that the right IPL responds selectively to the motoric and perceptual representations of actions and is the first evidence for a neural response in humans that shows both defining properties of mirror neurons.

  20. ERP adaptation provides direct evidence for early mirror neuron activation in the inferior parietal lobule.

    Science.gov (United States)

    Möhring, Nicole; Brandt, Emily S L; Mohr, Bettina; Pulvermüller, Friedemann; Neuhaus, Andres H

    2014-10-01

    Mirror neuron systems are frequently investigated by assessing overlapping brain activity during observation and execution of actions; however, distinct neuronal subpopulations may be activated that fall below the spatial resolution of magnetic resonance techniques. This shortfall can be resolved using repetition suppression paradigms that identify physiological adaptation processes caused by repeated activation of identical neuronal circuits. Here, event-related potentials were used to investigate the time course of mirror neuron circuit activation using repetition suppression within and across action observation and action execution modalities. In a lip-reading and speech production paradigm, the N170 component indexed stimulus repetition by adapting to both cross-modal and intra-modal repetitions in the left hemisphere. Neuronal source localization revealed activation of the left inferior parietal lobule during cross-modal relative to intra-modal trials. These results provide support for the position that the same neuronal circuits are activated in perceiving and performing articulatory actions. Moreover, our data strongly suggest that inferior parietal lobule mirror neurons are activated relatively early in time, which indicates partly automatic processes of linguistic perception and mirroring. Repetition suppression paradigms therefore help to elucidate neuronal correlates of different cognitive processes and may serve as a starting point for advanced electrophysiological research on mirror neurons.

  1. Differential roles for parietal and occipital cortices in visual working memory.

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    Daisuke Matsuyoshi

    Full Text Available Visual working memory (VWM is known as a highly capacity-limited cognitive system that can hold 3-4 items. Recent studies have demonstrated that activity in the intraparietal sulcus (IPS and occipital cortices correlates with the number of representations held in VWM. However, differences among those regions are poorly understood, particularly when task-irrelevant items are to be ignored. The present fMRI-based study investigated whether memory load-sensitive regions such as the IPS and occipital cortices respond differently to task-relevant information. Using a change detection task in which participants are required to remember pre-specified targets, here we show that while the IPS exhibited comparable responses to both targets and distractors, the dorsal occipital cortex manifested significantly weaker responses to an array containing distractors than to an array containing only targets, despite that the number of objects presented was the same for the two arrays. These results suggest that parietal and occipital cortices engage differently in distractor processing and that the dorsal occipital, rather than parietal, activity appears to reflect output of stimulus filtering and selection based on behavioral relevance.

  2. Biofidelic neck influences head kinematics of parietal and occipital impacts following short falls in infants.

    Science.gov (United States)

    Sullivan, Sarah; Coats, Brittany; Margulies, Susan S

    2015-09-01

    Falls are a major cause of traumatic head injury in children. Understanding head kinematics during low height falls is essential for evaluating injury risk and designing mitigating strategies. Typically, these measurements are made with commercial anthropomorphic infant surrogates, but these surrogates are designed based on adult biomechanical data. In this study, we improve upon the state-of-the-art anthropomorphic testing devices by incorporating new infant cadaver neck bending and tensile data. We then measure head kinematics following head-first falls onto 4 impact surfaces from 3 fall heights with occipital and parietal head impact locations. The biofidelic skull compliance and neck properties of the improved infant surrogate significantly influenced the measured kinematic loads, decreasing the measured impact force and peak angular accelerations, lowering the expected injury risk. Occipital and parietal impacts exhibited distinct kinematic responses in primary head rotation direction and the magnitude of the rotational velocities and accelerations, with larger angular velocities as the head rebounded after occipital impacts. Further evaluations of injury risk due to short falls should take into account the impact surface and head impact location, in addition to the fall height.

  3. Contextual modulation of pain in masochists: involvement of the parietal operculum and insula.

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    Kamping, Sandra; Andoh, Jamila; Bomba, Isabelle C; Diers, Martin; Diesch, Eugen; Flor, Herta

    2016-02-01

    Pain can be modulated by contextual stimuli, such as emotions, social factors, or specific bodily perceptions. We presented painful laser stimuli together with body-related masochistic visual stimuli to persons with and without preferred masochistic sexual behavior and used neutral, positive, and negative pictures with and without painful stimuli as control. Masochists reported substantially reduced pain intensity and unpleasantness in the masochistic context compared with controls but had unaltered pain perception in the other conditions. Functional magnetic resonance imaging revealed that masochists activated brain areas involved in sensory-discriminative processing rather than affective pain processing when they received painful stimuli on a masochistic background. The masochists compared with the controls displayed attenuated functional connectivity of the parietal operculum with the left and right insulae, the central operculum, and the supramarginal gyrus. Masochists additionally showed negative correlations between the duration of interest in masochistic activities and activation of areas involved in motor activity and affective processing. We propose that the parietal operculum serves as an important relay station that attenuates the affective-motivational aspects of pain in masochists. This novel mechanism of pain modulation might be related to multisensory integration and has important implications for the assessment and treatment of pain.

  4. Patterns of Activity in the Human Frontal and Parietal Cortex Differentiate Large and Small Saccades

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    Marie-Helene Grosbras

    2016-10-01

    Full Text Available A vast literature indicates that small and large saccades, respectively, subserve different perceptual and cognitive strategies and may rely on different programming modes. While it is well established that in monkeys’ main oculomotor brain regions small and large eye movements are controlled by segregated neuronal populations, the representation of saccade amplitude in the human brain remains unclear. To address this question we used functional magnetic resonance imaging (fMRI to scan participants while they performed saccades towards targets at either short (4 degrees or large (30 degrees eccentricity. A regional multivoxel pattern analysis (MVPA reveals that patterns of activity in the frontal (FEF and parietal eye fields discriminate between the execution of large or small saccades. This was not the case in the supplementary eye fields nor in the inferior precentral cortex. These findings provide the first evidence of a representation of saccadic eye movement size in the fronto-parietal occulomotor circuit. They shed light on the respective roles of the different cortical oculomotor regions with respect to space perception and exploration, as well as on the homology of eye movement control between human and non-human primates.

  5. Parietal and Frontal Cortex Encode Stimulus-Specific Mnemonic Representations during Visual Working Memory.

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    Ester, Edward F; Sprague, Thomas C; Serences, John T

    2015-08-19

    Working memory (WM) enables the storage and manipulation of information in an active state. WM storage has long been associated with sustained increases in activation across a network of frontal and parietal cortical regions. However, recent evidence suggests that these regions primarily encode information related to general task goals rather than feature-selective representations of specific memoranda. These goal-related representations are thought to provide top-down feedback that coordinates the representation of fine-grained details in early sensory areas. Here, we test this model using fMRI-based reconstructions of remembered visual details from region-level activation patterns. We could reconstruct high-fidelity representations of a remembered orientation based on activation patterns in occipital visual cortex and in several sub-regions of frontal and parietal cortex, independent of sustained increases in mean activation. These results challenge models of WM that postulate disjoint frontoparietal "top-down control" and posterior sensory "feature storage" networks. Copyright © 2015 Elsevier Inc. All rights reserved.

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

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

    2011-03-01

    While neurons in posterior parietal cortex have been found to signal the presence of a salient stimulus among multiple items in a display, spatial summation within their receptive field in the absence of an attentional bias has never been investigated. This information, however, is indispensable when one investigates the mechanisms of spatial attention and competition between multiple visual objects. To examine the spatial summation rule in parietal area 7a neurons, we trained rhesus monkeys to fixate on a central cross while two identical stimuli were briefly displayed in a neuron's receptive field. The response to a pair of dots was compared with the responses to the same dots when they were presented individually. The scaling and power parameters of a generalized summation algorithm varied greatly, both across neurons and across combinations of stimulus locations. However, the averaged response of the recorded population of 7a neurons was consistent with a winner-take-all rule for spatial summation. A control experiment where a monkey covertly attended to both stimuli simultaneously suggests that attention introduces additional competition by facilitating the less optimal stimulus. Thus an averaging stage is introduced between ∼ 200 and 300 ms of the response to a pair of stimuli. In short, the summation algorithm over the population of area 7a neurons carries the signature of a winner-take-all operation, with spatial attention possibly influencing the temporal dynamics of stimulus competition, that is the moment that the "winner" takes "victory" over the "loser" stimulus.

  7. Parietal subdural empyema as complication of acute odontogenic sinusitis: a case report

    Science.gov (United States)

    2014-01-01

    Introduction To date intracranial complication caused by tooth extractions are extremely rare. In particular parietal subdural empyema of odontogenic origin has not been described. A literature review is presented here to emphasize the extreme rarity of this clinical entity. Case presentation An 18-year-old Caucasian man with a history of dental extraction developed dysarthria, lethargy, purulent rhinorrhea, and fever. A computed tomography scan demonstrated extensive sinusitis involving maxillary sinus, anterior ethmoid and frontal sinus on the left side and a subdural fluid collection in the temporal-parietal site on the same side. He underwent vancomycin, metronidazole and meropenem therapy, and subsequently left maxillary antrostomy, and frontal and maxillary sinuses toilette by an open approach. The last clinical control done after 3 months showed a regression of all symptoms. Conclusions The occurrence of subdural empyema is an uncommon but possible sequela of a complicated tooth extraction. A multidisciplinary approach involving otolaryngologist, neurosurgeons, clinical microbiologist, and neuroradiologist is essential. Antibiotic therapy with surgical approach is the gold standard treatment. PMID:25146384

  8. Prolonged rock climbing activity induces structural changes in cerebellum and parietal lobe.

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    Di Paola, Margherita; Caltagirone, Carlo; Petrosini, Laura

    2013-10-01

    This article analyzes whether climbing, a motor activity featured by upward movements by using both feet and hands, generation of new strategies of motor control, maintenance of not stable equilibrium and adoption of long-lasting quadrupedal posture, is able to modify specific brain areas. MRI data of 10 word-class mountain climbers (MC) and 10 age-matched controls, with no climbing experience were acquired. Combining region-of-interest analyses and voxel-based morphometry we investigated cerebellar volumes and correlation between cerebellum and whole cerebral gray matter. In comparison to controls, world-class MC showed significantly larger vermian lobules I-V volumes, with no significant difference in other cerebellar vermian lobules or hemispheres. The cerebellar enlargement was associated with an enlargement of right medial posterior parietal area. The specific features of the motor climbing skills perfectly fit with the plastic anatomical changes we found. The enlargement of the vermian lobules I-V seems to be related to highly dexterous hand movements and to eye-hand coordination in the detection of and correction of visuomotor errors. The concomitant enlargement of the parietal area is related to parallel work in predicting sensory consequences of action to make movement corrections. Motor control and sensory-motor prediction of actions make the difference between survive or not at extreme altitude. Copyright © 2012 Wiley Periodicals, Inc.

  9. Longitudinal investigation of the parietal lobe anatomy in bipolar disorder and its association with general functioning.

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    Ferro, Adele; Bonivento, Carolina; Delvecchio, Giuseppe; Bellani, Marcella; Perlini, Cinzia; Dusi, Nicola; Marinelli, Veronica; Ruggeri, Mirella; Altamura, A Carlo; Crespo-Facorro, Benedicto; Brambilla, Paolo

    2017-09-30

    The parietal lobe (PL) supports cognitive domains, including attention and memory, which are impaired in bipolar disorder (BD). Although cross-sectional voxel-based morphometry studies found reduced PL grey matter (GM) in BD, none has longitudinally focused on PL anatomy in BD, relating it to patients' functioning. Thirty-eight right-handed BD patients and 42 matched healthy subjects (HS) underwent a Magnetic Resonance Imaging (MRI) scan at baseline. Seventeen BD patients and 16 matched HS underwent a follow-up MRI. PL white matter (WM) and GM volumes were measured. The trajectory of parietal volumes over time and the possible relation with the global functioning were investigated in both BD patients and HS. At baseline, BD patients showed significant reduced PL WM and GM and different WM laterality compared with HS. Furthermore, smaller PL WM volumes predicted lower global functioning in BD, but not in HS. At follow-up, although BD patients reported reduced PL WM compared with HS, no different pattern of volume changes over time was detected between groups. This study suggests the involvement of the PL in the pathophysiology of BD. In particular, PL WM reductions seem to predict an impairment in general functioning in BD and might represent a marker of functional outcome. Copyright © 2017. Published by Elsevier B.V.

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

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    Bradley Russell Buchsbaum

    2011-07-01

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

  11. 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.

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

    Science.gov (United States)

    Buchsbaum, Bradley R.; Ye, Donald; D'Esposito, Mark

    2011-01-01

    The most recently encountered information is often most easily remembered in psychological tests of memory. Recent investigations of the neural basis of such “recency effects” have shown that activation in the lateral inferior parietal cortex (LIPC) tracks the recency of a probe item when subjects make recognition memory judgments. A key question regarding recency effects in the LIPC is whether they fundamentally reflect the storage (and strength) of information in memory, or whether such effects are a consequence of task difficulty or an upswing in resting state network activity. Using functional magnetic resonance imaging we show that recency effects in the LIPC are independent of the difficulty of recognition memory decisions, that they are not a by-product of an increase in resting state network activity, and that they appear to dissociate from regions known to be involved in verbal working memory maintenance. We conclude with a discussion of two alternative explanations – the memory strength and “expectancy” hypotheses, respectively – of the parietal lobe recency effect. PMID:21811449

  13. Gastric hyperplasia and parietal cell loss in Taenia taeniaeformis inoculated immunodeficient mice.

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    Lagapa, Jose Trinipil; Konno, Kenjiro; Oku, Yuzaburo; Nonaka, Nariaki; Ito, Mamoru; Kamiya, Masao

    2002-03-01

    Immunodeficient mice were studied to determine their suitability as models in investigating the role of Taenia taeniaeformis larval products in the development of gastric hyperplasia. Recombinant active gene 2 (RAG2)-deficient and severe combined immune-deficient (SCID) mice were studied as candidate animal models. RAG2-deficient mice inoculated orally with T. taeniaeformis eggs developed gastric hyperplasia with alcian blue-periodic acid-Schiff-positive cell proliferation similar to those of rats. SCID mice inoculated with different doses and routes of T. taeniaeformis in vitro-hatched oncospheres and those orally inoculated with eggs resulted also in different degrees of gastric hyperplasia. Influence of inoculation forms of parasite, doses and routes of inoculation on initiation of hyperplastic gastropathy was suggested to be dependent on number and size of developed larvae. Both RAG2-deficient and SCID mice with hyperplastic mucosa were observed with significant loss of parietal cells. Apparent decrease in parietal cell number was observed in SCID mice at 2 weeks after intraperitoneal inoculation with oncospheres before hyperplastic lesions developed. Earliest occurrence of gastric hyperplasia in SCID mice was observed at 3 weeks after oral inoculation of in vitro-hatched oncospheres, sooner than orally inoculated rats. The results suggested that these immunodeficient mice could be used as animal models to study factors involved in T. taeniaeformis-induced gastric mucous cell hyperplasia.

  14. Alpha stimulation of the human parietal cortex attunes tactile perception to external space.

    Science.gov (United States)

    Ruzzoli, Manuela; Soto-Faraco, Salvador

    2014-02-03

    An intriguing question in neuroscience concerns how somatosensory events on the skin are represented in the human brain. Since Head and Holmes' [1] neuropsychological dissociation between localizing touch on the skin and localizing body parts in external space, touch is considered to operate in a variety of spatial reference frames [2]. At least two representations of space are in competition during orienting to touch: a somatotopic one, reflecting the organization of the somatosensory cortex (S1) [3], and a more abstract, external reference frame that factors postural changes in relation to body parts and/or external space [4, 5]. Previous transcranial magnetic stimulation (TMS) studies suggest that the posterior parietal cortex (PPC) plays a key role in supporting representations as well as orienting attention in an external reference frame [4, 6]. Here, we capitalized on the TMS entrainment approach [7, 8], targeting the intraparietal sulcus (IPS). We found that frequency-specific (10 Hz) tuning of the PPC induced spatially specific enhancement of tactile detection that was expressed in an external reference frame. This finding establishes a tight causal link between a concrete form of brain activity (10 Hz oscillation) and a specific type of spatial representation, revealing a fundamental property of how the parietal cortex encodes information.

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

    Directory of Open Access Journals (Sweden)

    Tomonori Kagawa

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

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

    Science.gov (United States)

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

    2010-01-01

    The anterior portion of the inferior parietal cortex possesses comprehensive representations of actions embedded in behavioural contexts. Mirror neurons, which respond to both self-executed and observed actions, exist in this brain region in addition to those originally found in the premotor cortex. We found that parietal mirror neurons responded differentially to identical actions embedded in different contexts. Another type of parietal mirror neuron represents an inverse and complementary property of responding equally to dissimilar actions made by itself and others for an identical purpose. Here, we propose a hypothesis that these sets of inferior parietal neurons constitute a neural basis for encoding the semantic equivalence of various actions across different agents and contexts. The neurons have mirror neuron properties, and they encoded generalization of agents, differentiation of outcomes, and categorization of actions that led to common functions. By integrating the activities of these mirror neurons with various codings, we further suggest that in the ancestral primates' brains, these various representations of meaningful action led to the gradual establishment of equivalence relations among the different types of actions, by sharing common action semantics. Such differential codings of the components of actions might represent precursors to the parts of protolanguage, such as gestural communication, which are shared among various members of a society. Finally, we suggest that the inferior parietal cortex serves as an interface between this action semantics system and other higher semantic systems, through common structures of action representation that mimic language syntax. PMID:20119879

  17. The role of the right parietal lobe in the perception of causality: a tDCS study.

    Science.gov (United States)

    Straube, Benjamin; Wolk, David; Chatterjee, Anjan

    2011-12-01

    Inferring causality is a fundamental feature of human cognition that allows us to predict outcomes in everyday events. Here, we use direct current stimulation (tDCS) to investigate the role of the right parietal lobe in the perception of causal events. Based on the results of a previous fMRI investigation, we hypothesized that the right parietal lobe plays a specific role in the processing of spatial attributes that contribute to judgments of causality. In line with our hypothesis, we found polarization-dependent modulation of causal judgments and corresponding reaction times (RTs) for trials with increasing violation of spatial contiguity in launching events. This effect was further modulated by temporal violations, as the effect of tDCS on the use of spatial information for causality judgements was strongest for trials with high temporal violations. Thus, especially for ambiguous trials with regard to temporal patterns, cathodal stimulation led to more liberal causality judgments for trials with high angles in movement trajectory. Furthermore, we found faster RTs after anodal stimulation of the right parietal lobe. These findings suggest a reduced influence of spatial attributes on the perception of causality after cathode stimulation of the right parietal lobe and an increased processing efficiency after anodal stimuli of the same region. These data demonstrate polarization-dependent tDCS modulation of spatial processing mechanisms within the right parietal lobe that contribute to the perception of causality.

  18. Brief asymmetric tonic posturing with diffuse low-voltage fast activity in seizures arising from the mesial parietal region.

    Science.gov (United States)

    Khan, Saad A; Carney, Patrick W; Archer, John S

    2014-12-01

    Seizures originating from the parietal lobe can demonstrate variable semiology. Our aim was to describe the electroclinical features of seizures originating from the mesial parietal lobe. We identified four patients through the Comprehensive Epilepsy Program at our institution, who had strong evidence of a mesial parietal source for their epilepsy, including a mesial parietal structural lesion. Patients had very frequent brief seizures despite anticonvulsants, each lasting 10-30s, with rapid return of awareness post-event. Clinically attacks were bland, or showed asymmetric tonic posturing, often with partially preserved awareness. Ictal EEG showed diffuse low voltage fast activity. Seizures arising from the precuneus, in the mesial parietal lobe, appear to have a recognizable electroclinical phenotype. Although the clinical and EEG features might have been considered 'non-localizing', there is a striking similarity across patients. The precuneus is a key component of the default mode network (DMN), important for internal reflective thinking. Deactivation of this region has been found to be a prominent feature of generalized spike and wave epileptiform activity. The seizure semiology of these patients presumably reflects activation of this region, and ictal propagation along intrinsically connected components of the DMN. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Functional connectivity between parietal and frontal brain regions and intelligence in young children: the Generation R study.

    Science.gov (United States)

    Langeslag, Sandra J E; Schmidt, Marcus; Ghassabian, Akhgar; Jaddoe, Vincent W; Hofman, Albert; van der Lugt, Aad; Verhulst, Frank C; Tiemeier, Henning; White, Tonya J H

    2013-12-01

    It has been shown in adults that individual differences in intelligence are related to the integrity of the interaction between parietal and frontal brain regions. Since connectivity between distant brain regions strengthens during childhood, it is unclear when in the course of development this relationship emerges. Thus, the goal of this study was to determine whether parietal-frontal functional connectivity is associated with intelligence in young children. We performed independent component analyses on resting-state fMRI data of 115 children (6-8 years old) to select seed and target regions for a seed/target region correlation analysis. We found that higher nonverbal intelligence was associated with increased functional connectivity between right parietal and right frontal regions, and between right parietal and dorsal anterior cingulate regions. The association between intelligence and functional connectivity between certain brain regions was stronger in girls than boys. In conclusion, we found that connectivity between the parietal and frontal lobes is critically involved in intelligence in young children. Copyright © 2012 Wiley Periodicals, Inc.

  20. Does Shape Discrimination by the Mouth Activate the Parietal and Occipital Lobes? – Near-Infrared Spectroscopy Study

    Science.gov (United States)

    Kagawa, Tomonori; Narita, Noriyuki; Iwaki, Sunao; Kawasaki, Shingo; Kamiya, Kazunobu; Minakuchi, Shunsuke

    2014-01-01

    A cross-modal association between somatosensory tactile sensation and parietal and occipital activities during Braille reading was initially discovered in tests with blind subjects, with sighted and blindfolded healthy subjects used as controls. However, the neural background of oral stereognosis remains unclear. In the present study, we investigated whether the parietal and occipital cortices are activated during shape discrimination by the mouth using functional near-infrared spectroscopy (fNIRS). Following presentation of the test piece shape, a sham discrimination trial without the test pieces induced posterior parietal lobe (BA7), extrastriate cortex (BA18, BA19), and striate cortex (BA17) activation as compared with the rest session, while shape discrimination of the test pieces markedly activated those areas as compared with the rest session. Furthermore, shape discrimination of the test pieces specifically activated the posterior parietal cortex (precuneus/BA7), extrastriate cortex (BA18, 19), and striate cortex (BA17), as compared with sham sessions without a test piece. We concluded that oral tactile sensation is recognized through tactile/visual cross-modal substrates in the parietal and occipital cortices during shape discrimination by the mouth. PMID:25299397

  1. Magnetic resonance imaging evaluation of meniscoid superior labrum: normal variant or superior labral tear*

    Science.gov (United States)

    Simão, Marcelo Novelino; Vinson, Emily N.; Spritzer, Charles E.

    2016-01-01

    Objective The objective of this study was to determine the incidence of a "meniscoid" superior labrum. Materials and Methods This was a retrospective analysis of 582 magnetic resonance imaging examinations of shoulders. Of those 582 examinations, 110 were excluded, for a variety of reasons, and the final analysis therefore included 472 cases. Consensus readings were performed by three musculoskeletal radiologists using specific criteria to diagnose meniscoid labra. Results A meniscoid superior labrum was identified in 48 (10.2%) of the 472 cases evaluated. Arthroscopic proof was available in 21 cases (43.8%). In 10 (47.6%) of those 21 cases, the operative report did not include the mention a superior labral tear, thus suggesting the presence of a meniscoid labrum. In only one of those cases were there specific comments about a mobile superior labrum (i.e., meniscoid labrum). In the remaining 11 (52.4%), surgical correlation demonstrated superior labral tears. Conclusion A meniscoid superior labrum is not an infrequent finding. Depending upon assumptions and the requirement of surgical proof, the prevalence of a meniscoid superior labrum in this study was between 2.1% (surgically proven) and 4.8% (projected). However, superior labral tears are just as common and are often confused with meniscoid labra. PMID:27777474

  2. Left medial parietal lobe and receptive language functions: mixed transcortical aphasia after left anterior cerebral artery infarction.

    Science.gov (United States)

    Ross, E D

    1980-02-01

    Three aphasic patients with infarctions involving the left anterior cerebral artery have been studied. Two had trancortical motor aphasia, and one had mixed transcortical (or isolation) aphasia. Based on computerized tomography in two patients and whole-brain sections in one, the patient with mixed transcortical aphasia had a lesion that went beyond the rolandic fissure to involve the anterior precuneus lobule of the left medial parietal lobe. In the patients with transcortical motor aphasia, the lesion was confined to the frontal lobe. From these cases and other data, it seems likely that the left medial parietal lobe has receptive language functions analogous to the motor language functions of the left medial frontal lobe, thus accounting for the mixed transcortical aphasia observed in the patient whose left anterior cerebral artery infarction involved both the medial parietal and medial frontal lobes.

  3. Coming unbound: disrupting automatic integration of synesthetic color and graphemes by transcranial magnetic stimulation of the right parietal lobe.

    Science.gov (United States)

    Esterman, Michael; Verstynen, Timothy; Ivry, Richard B; Robertson, Lynn C

    2006-09-01

    In some individuals, a visually presented letter or number automatically evokes the perception of a specific color, an experience known as color-grapheme synesthesia. It has been suggested that parietal binding mechanisms play a role in the phenomenon. We used a noninvasive stimulation technique, transcranial magnetic stimulation (TMS), to determine whether the posterior parietal lobe is critical for the integration of color and shape in color-grapheme synesthesia, as it appears to be for normal color-shape binding. Using a color-naming task with colored letters that were either congruent or incongruent with the synesthetic photism, we demonstrate that inhibition of the right posterior parietal lobe with repetitive TMS transiently attenuates synesthetic binding. These findings suggest that synesthesia (the induction of color from shape) relies on similar mechanisms as found in normal perception (where the perception of color is induced by wavelength).

  4. Acquired agraphia caused by focal brain damage.

    Science.gov (United States)

    Anderson, S W; Saver, J; Tranel, D; Damasio, H

    1993-03-01

    Motor and linguistic aspects of writing were evaluated in 31 subjects with focal damage in 1 of 3 regions of the left hemisphere: (1) dorsolateral frontal lobe sparing primary motor cortex (group FL), (2) parietal lobe (group PL), or (3) temporal lobe (group TL). A standard procedure was used to evaluate writing for grapheme formation, spatial arrangement, spelling, word selection, grammar, and perseveration. It was predicted that agraphia would be observed in all 3 groups, and that the most severe impairments would be associated with frontal lobe damage, particularly in aspects of writing dependent on sequencing (grapheme formation, spelling, and grammar). It was found that agraphia was common in all groups, particularly in the acute epoch, and that all groups showed considerable recovery of writing by the chronic epoch. Few differences were found between groups. However, the FL group was impaired on spelling and grammar relative to the PL group in the acute epoch and impaired on grammar relative to the TL group in the chronic epoch. The findings are consistent with the notion that writing relies on a distributed neuroanatomical network, which acts in concert to link fragments of visuomotor activity with component linguistic elements.

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

    Science.gov (United States)

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

    2010-08-01

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

  6. POSTOPERATIVE RECOVERY OF MUSCLE FORCE THROUGH MUSCLE TONING IN ABDOMINAL PARIETAL DEFECTS

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    Gabriela Monica Moacă

    2015-10-01

    Full Text Available The present paper’s aim is to elaborate a program of postoperative recovery for patients suffering from abdominal parietal defects, and to indicate the beneficial implications, both of the preoperative preparations and of the postoperative physiotherapist actions. The programs of functional postoperative recovery have been elaborated individually for the 254 patients under study – of which 139 belong to lot A (operated under a scheduled regime, after the preoperative preparation and 115 belong to lot B (operated in an emergency regime, in the General Surgery Clinic III of the University Emergency Hospital of Bucharest, between 1998 and 2009. The postoperative recovery program has been individualized for each patient, depending on his / her pathology and co-morbidities, and the physiotherapist has trained and took care that the patients should execute exercises of respiratory re-education, active mobilization of their limbs, coordinated with the breath, isometric exercises for the toning of their arms and legs and of the abdomen muscles. They started the muscle toning exercises slowly and increased them progressively in duration and intensity. The recovery started with isometric-type exercises and continued with the isotonic-type ones. Though mainly the abdominal muscles are aimed at, respectively the flexor muscles of the torso, the physiotherapy program shall comprise the toning of the other muscle groups of the torso, as well. It has been noticed - for the patients in lot A, compared to those of lot B - an obvious net favorable postoperative evolution, characterized through: a reduction of the respiratory, cardiac and thromboembolic complications, a quick postoperative recovery and the immediate social reintegration. An overview of the two lots proves the importance of the cardio-respiratory and locomotive preparation of the patients suffering from big abdominal parietal defects. The simple gestures of respiratory re-education, of

  7. Damage to the medial motor system in stroke patients with motor neglect

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    Raffaella eMigliaccio

    2014-06-01

    Full Text Available Background and objectives. Motor neglect (MN is a clinically important condition whereby patients with unilateral brain lesions fail to move their contralateral limbs, despite normal muscle strength, reflexes, and sensation. MN has been associated with various lesion sites, including the parietal and frontal cortex, the internal capsule, the lenticulostriate nuclei, and the thalamus. In the present study, we explored the hypothesis that MN depends on a dysfunction of the medial motor system by performing a detailed anatomical analysis in four patients with MN.Methods. Ten patients participated in the study: four with MN, four with left visual neglect but without MN, and three patients with left hemiplegia without MN. We used specific scales for clinical and neuropsychological assessment. We drew the lesion borders directly onto the original brain images of each patient, and plotted the lesions on anatomical atlases for grey and white matter. Results. Lesion locations were highly heterogeneous in our MN patients, and included frontal and parietal sites, basal ganglia and white matter. The only consistently damaged structure across all MN patients was the cingulum bundle, a major pathway of the medial motor system important for motor initiative, and a key connection with limbic structures crucial for motivational aspects of actions. Three MN patients with additional damage to lateral fronto-parietal networks had also signs of contralesional visual neglect. The cingulum bundle was intact in all the control patients with visual neglect or hemiplegia.Conclusions. Cingulum damage may induce MN through unilateral dysfunction of the medial motor system. Additional lateral fronto-parietal dysfunction can result in the association with visual neglect.

  8. Neurologic Outcome After Resection of Parietal Lobe Including Primary Somatosensory Cortex: Implications of Additional Resection of Posterior Parietal Cortex.

    Science.gov (United States)

    Kim, Young-Hoon; Kim, June Sic; Lee, Sang Kun; Chung, Chun Kee

    2017-10-01

    Postoperative neurologic outcomes after primary somatosensory cortex (S1) resection have not been well documented. This study was designed to evaluate the neurologic deterioration that follows resection of the S1 areas and to assess the risk factors associated with these morbidities. We reviewed 48 consecutive patients with medically intractable epilepsy who underwent resection of the S1 and/or the adjacent cortex. The 48 patients were categorized into 4 groups according to the resected area as seen on postoperative magnetic resonance images: group 1 (resection of S1 only; n = 4), 2 (the posterior parietal cortex [PPC] only; n = 24), 3 (S1 and PPC; n = 10), and 4 (S1 and precentral gyrus; n = 10). After the resection of S1 areas, 19 patients (40%) experienced neurologic worsening, including 6 (13%) with permanent and 13 (27%) with transient deficits. Patients with permanent deficits included 2 with motor dysphasia, 1 with dysesthesia, 2 with equilibrium impairments, and 1 with fine movement disturbance of the hand. The overall and permanent neurologic risks were 25% and 0% in group 1, 17% and 4% in group 2, 80% and 20% in group 3, and 60% and 30% in group 4, respectively. Multivariate analysis determined that the resection of both S1 and PPC was the only significant risk factor for neurologic deficits (P = 0.002). The neurologic risk of the resection of S1 and/or its adjacent cortical areas was 40%. The additional resection of the PPC was significantly associated with the development of postoperative neurologic impairments. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Cross-frequency power correlations reveal the right superior temporal gyrus as a hub region during working memory maintenance.

    Science.gov (United States)

    Park, Hyojin; Kang, Eunjoo; Kang, Hyejin; Kim, June Sic; Jensen, Ole; Chung, Chun Kee; Lee, Dong Soo

    2011-01-01

    In the present study, we characterized within- and cross-frequency power correlations from magnetoencephalography (MEG) data in order to understand how different brain regions cooperate as a network to maintain working memory representations with several features. The working memory items were composed of spatially arranged dots supposedly requiring both the dorsal and the ventral stream to be engaged during maintenance. Using a beamforming technique, we localized memory-dependent sources in the alpha, beta, and gamma bands. After the single-trial power values were extracted from these frequency bands with respect to each source, we calculated the correlations within- and cross-frequency bands. The following general picture emerged: gamma power in right superior temporal gyrus (STG) during working memory maintenance was correlated with numerous other sources in the alpha band in prefrontal, parietal, and posterior regions. In addition, the power correlations within the alpha band showed correlations across posterior-parietal-frontal regions. From these findings, we suggest that the STG dominated by gamma activity serves as a hub region for the network nodes responsible for the retention of the stimulus used in this study, which is likely to depend on both the "where-" and the "what-" visual system simultaneously. The present study demonstrates how oscillatory dynamics reflecting the interaction between cortical areas can be investigated by means of cross-frequency power correlations in source space. This methodological framework could be of general utility when studying functional network properties of the working brain.

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

    DEFF Research Database (Denmark)

    Reichenbach, Alexandra; Thielscher, Axel; Peer, Angelika

    2014-01-01

    neuroimaging studies have focused mainly on identifying the parts of the posterior parietal cortex (PPC) that contribute to visually guided movements. We used event-related TMS and force perturbations of the reaching hand to test whether the same sub-regions of the left PPC contribute to the processing...... of proprioceptive-only and of multi-sensory information about hand position when reaching for a visual target. TMS over two distinct stimulation sites elicited differential effects: TMS applied over the posterior part of the medial intraparietal sulcus (mIPS) compromised reaching accuracy when proprioception...... was the only sensory information available for correcting the reaching error. When visual feedback of the hand was available, TMS over the anterior intraparietal sulcus (aIPS) prolonged reaching time. Our results show for the first time the causal involvement of the posterior mIPS in processing proprioceptive...

  11. Conduction Aphasia as a Result of Left Parietal-Temporal-Occipital Anaplastic Astrocytoma: A Case Study

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    Oscar Mauricio Aguilar Mejía

    2011-01-01

    Full Text Available Conduction aphasia is a language disorder characterized by an impaired ability to repeat verbal material associated with phonological paraphasias but a relatively fluent spontaneous speech and preserved comprehension. It has been attributed to lesions of the arcuate fasciculus by disconnection between posterior temporal lobe and frontal lobe, however, this idea has been debated, because the integrity and function of the arcuate fasciculus does not seem to be essential in verbal repetition. We report a case of a 23 year old male, with conduction aphasia as a result of a recurrent anaplastic astrocytoma in parietal and temporo-occipital areas. We propose a reconceptualization of the aphasia, analyzing it in terms of clinical neuropsychological and neural networks between ipsilateral and contralateral posterior brain areas

  12. [Signal transudation pathways in parietal cells of the gastric mucosa in experimental stomach ulcer].

    Science.gov (United States)

    Ostapchenko, L I; Drobins'ka, O V; Chaĭka, V O; Bohun, L I; Bohdanova, O V; Kot, L I; Haĭda, L M

    2009-01-01

    The goal of the presented work was the research of signal transduction mechanism in the rat gastric parietal cells under stomach ulcer conditions. In these cells activation of adenylate cyclase (increase of cAMP level and proteinkinase A activity) and phosphoinositide (increases [Ca2+]i; cGMP and phoshatidylinocitole levels; proteinkinase C, proteinkinase G, and calmodulin-dependent-proteinkinase activity) of signals pathway was shown. An increase of plasma membrane phospholipids (PC, PS, PE, PI, LPC) level was shown. Under conditions of influence of the stress factor the membran enzymes activity (H+, K+ -ATPase, 5'-AMPase, Na+, K+ -ATPase, Ca2+, Mg2+ -ATPase and H+, K+ -ATPase) was considerably increased. The intensification of lipid peroxidation processes in rats was demonstrated.

  13. Cognitive Contributions of the Ventral Parietal Cortex: An Integrative Theoretical Account

    Science.gov (United States)

    Cabeza, Roberto; Ciaramelli, Elisa; Moscovitch, Morris

    2012-01-01

    Although ventral parietal cortex (VPC) activations can be found in a variety of cognitive domains, these activations have been typically attributed to cognitive operations specific to each domain. In this article, we propose a hypothesis that can account for VPC activations across all the cognitive domains reviewed. We first review VPC activations in the domains of perceptual and motor reorienting, episodic memory retrieval, language and number processing, theory of mind, and episodic memory encoding. Then, we consider the localization of VPC activations across domains, and conclude that they are largely overlapping with some differences around the edges. Finally, we assess how well four different hypotheses of VPC function can explain findings in various domains, and conclude that a bottom-up attention hypothesis provides the most complete and parsimonious account. PMID:22609315

  14. Agnosia for Mirror Stimuli: A New Case Report with a Small Parietal Lesion

    Science.gov (United States)

    Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Lebas, Axel; Gerardin, Emmanuel; Hannequin, Didier

    2014-01-01

    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. PMID:25037846

  15. Cognitive contributions of the ventral parietal cortex: an integrative theoretical account.

    Science.gov (United States)

    Cabeza, Roberto; Ciaramelli, Elisa; Moscovitch, Morris

    2012-06-01

    Although ventral parietal cortex (VPC) activations can be found in a variety of cognitive domains, these activations have been typically attributed to cognitive operations specific to each domain. In this article, we propose a hypothesis that can account for VPC activations across all the cognitive domains reviewed. We first review VPC activations in the domains of perceptual and motor reorienting, episodic memory retrieval, language and number processing, theory of mind, and episodic memory encoding. Then, we consider the localization of VPC activations across domains and conclude that they are largely overlapping with some differences around the edges. Finally, we assess how well four different hypotheses of VPC function can explain findings in various domains and conclude that a bottom-up attention hypothesis provides the most complete and parsimonious account.

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

    Science.gov (United States)

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

    2009-09-01

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

  17. Representation of accumulating evidence for a decision in two parietal areas.

    Science.gov (United States)

    de Lafuente, Victor; Jazayeri, Mehrdad; Shadlen, Michael N

    2015-03-11

    Decisions are often made by accumulating evidence for and against the alternatives. The momentary evidence represented by sensory neurons is accumulated by downstream structures to form a decision variable, linking the evolving decision to the formation of a motor plan. When decisions are communicated by eye movements, neurons in the lateral intraparietal area (LIP) represent the accumulation of evidence bearing on the potential targets for saccades. We now show that reach-related neurons from the medial intraparietal area (MIP) exhibit a gradual modulation of their firing rates consistent with the representation of an evolving decision variable. When decisions were communicated by saccades instead of reaches, decision-related activity was attenuated in MIP, whereas LIP neurons were active while monkeys communicated decisions by saccades or reaches. Thus, for decisions communicated by a hand movement, a parallel flow of sensory information is directed to parietal areas MIP and LIP during decision formation.

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

    Science.gov (United States)

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

    2013-03-01

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

  19. Reconstruction of facial defects after combat wounding using vascularized pedicled galeal and parietal bony grafts

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    Jović Nebojša

    2002-01-01

    Full Text Available Combat wounds are basically extensive and destructive. Such injuries cause defects of soft and bone structures of the face and neck. During primary surgical management of maxillofacial combat wounds the principle of minimal bone and soft tissue debridement was respected. Definitive reconstruction of the defect was performed after two or three months, when infection was cured and adjacent tissues were restituted. Each combat wound leaves behind fibrous changes in surrounding tissues. Success of the reconstructive procedures is more certain if flaps with its own blood supply are used, either arterial or vascularized grafts from the other parts of body (by microvascular technique. This paper presents our experiences with galeal flap in reconstruction of facial soft tissue defects, as well as galea, together with external table of parietal bone in reconstruction of soft and bony tissues of maxillofacial region in 15 patients.

  20. Distinct neural mechanisms of distractor suppression in the frontal and parietal lobe.

    Science.gov (United States)

    Suzuki, Mototaka; Gottlieb, Jacqueline

    2013-01-01

    The posterior parietal cortex and the prefrontal cortex are associated with eye movements and visual attention, but their specific contributions are poorly understood. We compared the dorsolateral prefrontal cortex (dlPFC) and the lateral intraparietal area (LIP) in monkeys using a memory saccade task in which a salient distractor flashed at a variable timing and location during the memory delay. We found that the two areas had similar responses to target selection, but made distinct contributions to distractor suppression. Distractor responses were more strongly suppressed and more closely correlated with performance in the dlPFC relative to LIP. Moreover, reversible inactivation of the dlPFC produced much larger increases in distractibility than inactivation of LIP. These findings suggest that LIP and dlPFC mediate different aspects of selective attention. Although both areas can contribute to the perceptual selection of salient information, the dlPFC has a decisive influence on whether and how attended stimulus is linked with actions.

  1. Paroxysmal posterior variant alien hand syndrome associated with parietal lobe infarction: case presentation.

    Science.gov (United States)

    Demiryürek, Bekir Enes; Gündogdu, Aslı Aksoy; Acar, Bilgehan Atılgan; Alagoz, Aybala Neslihan

    2016-10-01

    Alien hand syndrome (AHS) is an involuntary and rare neurological disorder emerges at upper extremity. AHS is a disconnection syndrome with the symptoms of losing sense of agency and sense of ownership, and presence of involuntary autonomic motor activity. There are frontal, callosal and posterior types of AHS and each of them occurs depend on the lesions of different of the brain. Posterior variant is a rarely encountered AHS type compared to others. AHS, generally regarded as persistent, but rarely maybe observed as paroxysmal. In this article, we present 71 year old patient with right posterior parietal lobe infarction and developed posterior variant AHS on left arm 1 month after discharge from the hospital. To discriminate AHS from conditions such as extrapyramidal movement disorders and epileptic seizures that take part in differential diagnosis should be kept in mind by the clinicians. Wrong and unnecessary treatments could be prevented in this way.

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

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    Alberto Gallace

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

  3. Surface Reconstruction from Parallel Curves with Application to Parietal Bone Fracture Reconstruction.

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    Abdul Majeed

    Full Text Available Maxillofacial trauma are common, secondary to road traffic accident, sports injury, falls and require sophisticated radiological imaging to precisely diagnose. A direct surgical reconstruction is complex and require clinical expertise. Bio-modelling helps in reconstructing surface model from 2D contours. In this manuscript we have constructed the 3D surface using 2D Computerized Tomography (CT scan contours. The fracture part of the cranial vault are reconstructed using GC1 rational cubic Ball curve with three free parameters, later the 2D contours are flipped into 3D with equidistant z component. The constructed surface is represented by contours blending interpolant. At the end of this manuscript a case report of parietal bone fracture is also illustrated by employing this method with a Graphical User Interface (GUI illustration.

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

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    Thomas C Bulea

    2015-05-01

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

  5. 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.

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

    Science.gov (United States)

    Wendelken, Carter

    2014-01-01

    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 reasoning.

  7. Alpha power increases in right parietal cortex reflects focused internal attention.

    Science.gov (United States)

    Benedek, Mathias; Schickel, Rainer J; Jauk, Emanuel; Fink, Andreas; Neubauer, Aljoscha C

    2014-04-01

    This study investigated the functional significance of EEG alpha power increases, a finding that is consistently observed in various memory tasks and specifically during divergent thinking. It was previously shown that alpha power is increased when tasks are performed in mind-e.g., when bottom-up processing is prevented. This study aimed to examine the effect of task-immanent differences in bottom-up processing demands by comparing two divergent thinking tasks, one intrinsically relying on bottom-up processing (sensory-intake task) and one that is not (sensory-independence task). In both tasks, stimuli were masked in half of the trials to establish conditions of higher and lower internal processing demands. In line with the hypotheses, internal processing affected performance and led to increases in alpha power only in the sensory-intake task, whereas the sensory-independence task showed high levels of task-related alpha power in both conditions. Interestingly, conditions involving focused internal attention showed a clear lateralization with higher alpha power in parietal regions of the right hemisphere. Considering evidence from fMRI studies, right-parietal alpha power increases may correspond to a deactivation of the right temporoparietal junction, reflecting an inhibition of the ventral attention network. Inhibition of this region is thought to prevent reorienting to irrelevant stimulation during goal-driven, top-down behavior, which may serve the executive function of task shielding during demanding cognitive tasks such as idea generation and mental imagery. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. 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

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

    Science.gov (United States)

    Andres, Michael; Pelgrims, Barbara; Olivier, Etienne

    2013-09-01

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

  10. Exploring the contributions of premotor and parietal cortex to spatial compatibility using image-guided TMS.

    Science.gov (United States)

    Koski, Lisa; Molnar-Szakacs, Istvan; Iacoboni, Marco

    2005-01-15

    Functional brain imaging studies have demonstrated increased activity in dorsal premotor and posterior parietal cortex when performing spatial stimulus-response compatibility tasks (SRC). We tested the specific role of these regions in stimulus-response mapping using single-pulse transcranial magnetic stimulation (TMS). Subjects were scanned using functional magnetic resonance imaging (fMRI) prior to the TMS session during performance of a task in which spatial compatibility was manipulated. For each subject, the area of increased signal within the regions of interest was registered onto their own high-resolution T1-weighted anatomic scan. TMS was applied to these areas for each subject using a frameless stereotaxic system. Task accuracy and reaction time (RT) were measured during blocks of compatible or incompatible trials and during blocks of real TMS or sham stimulation. On each trial, a single TMS pulse was delivered at 50, 100, 150, or 200 ms after the onset of the stimulus in the left or right visual field. TMS over the left premotor cortex produced various facilitatory effects, depending on the timing of the stimulation. At short intervals, TMS appeared to prime the left dorsal premotor cortex to select a right-hand response more quickly, regardless of stimulus-response compatibility. The strongest effect of stimulation, however, occurred at the 200-ms interval, when TMS facilitated left-hand responses during the incompatible condition. Facilitation of attention to the contralateral visual hemifield was observed during stimulation over the parietal locations. We conclude that the left premotor cortex is one of the cortical regions responsible for overriding automatic stimulus-response associations.

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

    Directory of Open Access Journals (Sweden)

    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

  12. Evolution of mammalian sensorimotor cortex: Thalamic projections to parietal cortical areas in Monodelphis domestica

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    James Clinton Dooley

    2015-01-01

    Full Text Available The current experiments build upon previous studies designed to reveal the network of parietal cortical areas present in the common mammalian ancestor. Understanding this ancestral network is essential for highlighting the basic somatosensory circuitry present in all mammals, and how this basic plan was modified to generate species specific behaviors. Our animal model, the short-tailed opossum (Monodelphis domestica, is a South American marsupial that has been proposed to have a similar ecological niche and morphology to the earliest common mammalian ancestor. In this investigation, we injected retrograde neuroanatomical tracers into the face and body representations of primary somatosensory cortex (S1, the rostral and caudal somatosensory fields (SR and SC, as well as a multimodal region (MM. Projections from different architectonically defined thalamic nuclei were then quantified. Our results provide further evidence to support the hypothesized basic mammalian plan of thalamic projections to S1, with the lateral and medial ventral posterior thalamic nuclei (VPl and VPm projecting to S1 body and S1 face, respectively. Additional strong projections are from the medial division of posterior nucleus (Pom. SR receives projections from several midline nuclei, including the medial dorsal, ventral medial nucleus, and Pom. SC and MM show similar patterns of connectivity, with projections from the ventral anterior and ventral lateral nuclei, VPm and VPl, and the entire posterior nucleus (medial and lateral. Notably, MM is distinguished from SC by relatively dense projections from the dorsal division of the lateral geniculate nucleus and pulvinar. We discuss the finding that S1 of the short-tailed opossum has a similar pattern of projections as other marsupials and mammals, but also some distinct projections not present in other mammals. Further we provide additional support for a primitive posterior parietal cortex which receives input from multiple

  13. Computer modeling of gastric parietal cell: significance of canalicular space, gland lumen, and variable canalicular [K+].

    Science.gov (United States)

    Crothers, James M; Forte, John G; Machen, Terry E

    2016-05-01

    A computer model, constructed for evaluation of integrated functioning of cellular components involved in acid secretion by the gastric parietal cell, has provided new interpretations of older experimental evidence, showing the functional significance of a canalicular space separated from a mucosal bath by a gland lumen and also shedding light on basolateral Cl(-) transport. The model shows 1) changes in levels of parietal cell secretion (with stimulation or H-K-ATPase inhibitors) result mainly from changes in electrochemical driving forces for apical K(+) and Cl(-) efflux, as canalicular [K(+)] ([K(+)]can) increases or decreases with changes in apical H(+)/K(+) exchange rate; 2) H-K-ATPase inhibition in frog gastric mucosa would increase [K(+)]can similarly with low or high mucosal [K(+)], depolarizing apical membrane voltage similarly, so electrogenic H(+) pumping is not indicated by inhibition causing similar increase in transepithelial potential difference (Vt) with 4 and 80 mM mucosal K(+); 3) decreased H(+) secretion during strongly mucosal-positive voltage clamping is consistent with an electroneutral H-K-ATPase being inhibited by greatly decreased [K(+)]can (Michaelis-Menten mechanism); 4) slow initial change ("long time-constant transient") in current or Vt with clamping of Vt or current involves slow change in [K(+)]can; 5) the Na(+)-K(+)-2Cl(-) symporter (NKCC) is likely to have a significant role in Cl(-) influx, despite evidence that it is not necessary for acid secretion; and 6) relative contributions of Cl(-)/HCO3 (-) exchanger (AE2) and NKCC to Cl(-) influx would differ greatly between resting and stimulated states, possibly explaining reported differences in physiological characteristics of stimulated open-circuit Cl(-) secretion (≈H(+)) and resting short-circuit Cl(-) secretion (>H(+)).

  14. Whole network, temporal and parietal lobe contributions to the earliest phases of language production.

    Science.gov (United States)

    Principe, Alessandro; Calabria, Marco; Campo, Adrià Tauste; Cruzat, Josephine; Conesa, Gerardo; Costa, Albert; Rocamora, Rodrigo

    2017-10-01

    We investigated whether it is possible to study the network dynamics and the anatomical regions involved in the earliest moments of picture naming by using invasive electroencephalogram (EEG) traces to predict naming errors. Four right-handed participants with focal epilepsy explored with extensive stereotactic implant montages that recorded temporal, parietal and occipital regions -in two patients of both hemispheres-named a total of 228 black and white pictures in three different sessions recorded in different days. The subjects made errors that involved anomia and semantic dysphasia, which related to word frequency and not to visual complexity. Using different modalities of spectrum analysis and classification with a support vector machine (SVM) we could predict errors with rates that ranged from slightly above chance level to 100%, even in the preconscious phase, i.e., 100 msec after stimulus presentation. The highest rates were obtained using the gamma bands of all contact spectra without averaging, which implies a fine modulation of the neuronal activity at a network level. Despite no subset of nodes could match the whole set, rates close to the best prediction scores were obtained through the spectra of the temporal-parietal and temporal-occipital junction along with the temporal pole and hippocampus. When both hemispheres were explored nodes from the left side dominated in the best subsets. We argue that posterior temporal regions, especially of the dominant side, are involved very early, even in the preconscious phase (100 msec), in language production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Frontal lobe and posterior parietal contributions to the cortico-cerebellar system.

    Science.gov (United States)

    Ramnani, Narender

    2012-06-01

    Our growing understanding of how cerebral cortical areas communicate with the cerebellum in primates has enriched our understanding of the data that cerebellar circuits can access, and the neocortical areas that cerebellar activity can influence. The cerebellum is part of some large-scale networks involving several parts of the neocortex including association areas in the frontal lobe and the posterior parietal cortex that are known for their contributions to higher cognitive function. Understanding their connections with the cerebellum informs the debates around the role of the cerebellum in higher cognitive functions because they provide mechanisms through which association areas and the cerebellum can influence each others' operations. In recent years, evidence from connectional anatomy and human neuroimaging have comprehensively overturned the view that the cerebellum contributes only to motor control. The aim of this review is to examine our changing perspectives on the nature of cortico-cerebellar anatomy and the ways in which it continues to shape our views on its contributions to function. The review considers the anatomical connectivity of the cerebellar cortex with frontal lobe areas and the posterior parietal cortex. It will first focus on the anatomical organisation of these circuits in non-human primates before discussing new findings about this system in the human brain. It has been suggested that in non-human primates "although there is a modest input from medial prefrontal cortex, there is very little or none from the more lateral prefrontal areas" [33]. This review discusses anatomical investigations that challenge this claim. It also attempts to dispel the misconception that prefrontal projections to the cerebellum are from areas concerned only with the kinematic control of eye movements. Finally, I argue that our revised understanding of anatomy compels us to reconsider conventional views of how these systems operate in the human brain.

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

    Science.gov (United States)

    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

  17. Motor and parietal cortex stimulation for phantom limb pain and sensations.

    Science.gov (United States)

    Bolognini, Nadia; Olgiati, Elena; Maravita, Angelo; Ferraro, Francesco; Fregni, Felipe

    2013-08-01

    Limb amputation may lead to chronic painful sensations referred to the absent limb, ie phantom limb pain (PLP), which is likely subtended by maladaptive plasticity. The present study investigated whether transcranial direct current stimulation (tDCS), a noninvasive technique of brain stimulation that can modulate neuroplasticity, can reduce PLP. In 2 double-blind, sham-controlled experiments in subjects with unilateral lower or upper limb amputation, we measured the effects of a single session of tDCS (2 mA, 15 min) of the primary motor cortex (M1) and of the posterior parietal cortex (PPC) on PLP, stump pain, nonpainful phantom limb sensations and telescoping. Anodal tDCS of M1 induced a selective short-lasting decrease of PLP, whereas cathodal tDCS of PPC induced a selective short-lasting decrease of nonpainful phantom sensations; stump pain and telescoping were not affected by parietal or by motor tDCS. These findings demonstrate that painful and nonpainful phantom limb sensations are dissociable phenomena. PLP is associated primarily with cortical excitability shifts in the sensorimotor network; increasing excitability in this system by anodal tDCS has an antalgic effect on PLP. Conversely, nonpainful phantom sensations are associated to a hyperexcitation of PPC that can be normalized by cathodal tDCS. This evidence highlights the relationship between the level of excitability of different cortical areas, which underpins maladaptive plasticity following limb amputation and the phenomenology of phantom limb, and it opens up new opportunities for the use of tDCS in the treatment of PLP.

  18. Superior-subordinate relations as organizational processes

    DEFF Research Database (Denmark)

    Asmuss, Birte; Aggerholm, Helle Kryger; Oshima, Sae

    Since the emergence of the practice turn in social sciences (Golsorkhi et al. 2010), studies have shown a number of institutionally relevant aspects as achievements across time and by means of various resources (human and non-human) (Taylor & van Every 2000, Cooren et al. 2006). Such a process view...... superior-subordinate relations in a specific institutionalized setting: performance appraisal interviews (PAIs). While one main task of PAIs is to manage and integrate organizational and employee performance (Fletcher, 2001:473), PAIs are also organizational practices where superior-subordinate relations...... are shaped, (re)confirmed and re-evaluated. This paper pursues the better understanding of the latter aspect by looking at one substantial and recurrent activity in PAIs: the evaluation of employee performance. One resource for doing the evaluation work is making assessments (e.g. Goodwin & Goodwin, 1987...

  19. Exploring the word superiority effect using TVA

    DEFF Research Database (Denmark)

    Starrfelt, Randi

    Words are made of letters, and yet sometimes it is easier to identify a word than a single letter. This word superiority effect (WSE) has been observed when written stimuli are presented very briefly or degraded by visual noise. It is unclear, however, if this is due to a lower threshold...... for perception of words, or a higher speed of processing for words than letters. We have investigated the WSE using methods based on a Theory of Visual Attention. In an experiment using single stimuli (words or letters) presented centrally, we show that the classical WSE is specifically reflected in perceptual...... processing speed: words are simply processed faster than single letters. It is also clear from this experiment, that the word superiority effect can be observed at a large range of exposure durations, from the perceptual threshold to ceiling performance. Intriguingly, when multiple stimuli are presented...

  20. Dor central devida a compressão do cortex parietal por tumor cerebral: relato de dois casos Central pain from cerebral cortical parietal tumors: report of two cases

    Directory of Open Access Journals (Sweden)

    Edson José Amâncio

    2002-06-01

    Full Text Available Dor central produzida por tumores cerebrais é considerada rara pela maioria dos autores. Os poucos casos descritos na literatura fazem referência à dor central provocada pela presença de lesões expansivas acometendo o córtex parietal contralateral. Nem mesmo os tumores talâmicos costumam produzir dor central. Apresentamos dois casos de dor central associada a lesões expansivas que acometeram o córtex parietal, 1 astrocitoma low grade e 1 meningioma. Em ambos houve alívio da dor após a remoção cirúrgica das lesões.Central pain derived from cerebral tumors is considered rare by most authors. The few cases described in literature refer to central pain caused by expansive lesions in the contralatral parietal cortex. Usually, not even thalamic tumors cause central pain. We describe two cases of central pain related to expansive lesions in the parietal cortical region -- a low grade astrocytoma and a meningioma. Both patients reported pain relief after lesions were removed by surgery.

  1. Resolution of superior oblique myokymia with memantine.

    Science.gov (United States)

    Jain, Saurabh; Farooq, Shegufta J; Gottlob, Irene

    2008-02-01

    We describe a novel treatment of superior oblique myokymia. A 40-year-old woman was treated with gabapentin for this disorder with partial success and reported significant side effects including loss of libido and weight gain. After a drug holiday, memantine therapy was initiated resulting in a substantial improvement in her symptoms with far fewer side effects and stability on long-term maintenance therapy.

  2. Locked Superior Dislocation of the Acromioclavicular Joint

    Directory of Open Access Journals (Sweden)

    Salma Eltoum Elamin

    2013-01-01

    Full Text Available Acromioclavicular (AC joint injuries account for approximately 3–5% of shoulder girdle injuries (Rockwood et al., 1998. Depending on severity of injury and direction of displacement these are classified using Rockwood classification system for AC joint dislocation. We present an unusual case presenting with locked superior dislocation of the AC joint highlighting the presentation and subsequent successful surgical management of such case. To our knowledge this has not been reported previously in literature.

  3. Reperfusion hemorrhage following superior mesenteric artery stenting.

    LENUS (Irish Health Repository)

    Moore, Michael

    2012-02-03

    Percutaneous transluminal angioplasty and stent placement is now an established treatment option for chronic mesenteric ischemia and is associated with low mortality and morbidity rates. We present a case of reperfusion hemorrhage complicating endovascular repair of superior mesenteric artery stenosis. Although a recognized complication following repair of carotid stenosis, hemorrhage has not previously been reported following mesenteric endovascular reperfusion. We describe both spontaneous cessation of bleeding and treatment with coil embolization.

  4. Superior mesenteric artery compression syndrome - case report

    Directory of Open Access Journals (Sweden)

    Paulo Rocha França Neto

    2011-12-01

    Full Text Available Superior mesenteric artery syndrome is an entity generally caused by the loss of the intervening mesenteric fat pad, resulting in compression of the third portion of the duodenum by the superior mesenteric artery. This article reports the case of a patient with irremovable metastatic adenocarcinoma in the sigmoid colon, that evolved with intense vomiting. Intestinal transit was carried out, which showed important gastric dilation extended until the third portion of the duodenum, compatible with superior mesenteric artery syndrome. Considering the patient's nutritional condition, the medical team opted for the conservative treatment. Four months after the surgery and conservative measures, the patient did not present vomiting after eating, maintaining previous weight. Superior mesenteric artery syndrome is uncommon and can have unspecific symptoms. Thus, high suspicion is required for the appropriate clinical adjustment. A barium examination is required to make the diagnosis. The treatment can initially require gastric decompression and hydration, besides reversal of weight loss through adequate nutrition. Surgery should be adopted only in case of clinical treatment failure.A síndrome da artéria mesentérica superior é uma entidade clínica causada geralmente pela perda do tecido adiposo mesentérico, resultando na compressão da terceira porção do duodeno pela artéria mesentérica superior. Esse artigo relata o caso clínico de uma paciente portadora de adenocarcinoma de cólon sigmoide metastático irressecável, que evoluiu com vômitos incoercíveis. Realizou-se, então, trânsito intestinal que evidenciou dilatação gástrica importante, que se prolongava até a terceira porção duodenal, quadro radiológico compatível com pinçamento da artéria mesentérica superior. Diante da condição nutricional da paciente, foi optado por iniciar medidas conservadoras (porções alimentares pequenas e mais frequentes, além de dec

  5. "Sleeping Beauty paraphilia": deviant desire in the context of bodily self-image disturbance in a patient with a fronto-parietal traumatic brain injury.

    Science.gov (United States)

    Bianchi-Demicheli, Francesco; Rollini, Christian; Lovblad, Karl; Ortigue, Stephanie

    2010-02-01

    Several case series and reports describe paraphilia as occurring after brain damage, mostly in the frontal lobes and diencephalic structures. Hypersexuality and paraphilic behaviors are also documented in a variety of other neurologic disorders, (e.g., Kluver Bucy syndrome, and more rarely in multiple sclerosis). In multiple sclerosis, hypersexual behavior and paraphilias have been associated with various focal brain lesions in the frontal and temporal lesions when inflammatory demyelination involves the hypothalamus and septal regions. A case of a patient who developed a particular and progressive sexual deviant behaviour after a head trauma. This men felt sexually aroused from seeing sleeping women as well as from taking care of their hands and nails while they were asleep. The patient was diagnosed with a moderate dysexecutive syndrome characteristic of a frontal disorder and a very specific parietal-related bodily self image disorder characterized by an incomplete mental image of his hands. The clinical hypothesis was that the paraphilia might be related to his post-traumatic disturbed bodily self image and more specifically to its related impulsive needs to complete his hands representation. This case report highlights the potential link between paraphilia, deviant and aggressive sexual behaviour, neurological disturbance and self-representation. The treatment of paraphilias remains very complex, and requires taking into account not only the social and psychological aspects of the disease, but also its organic dimensions.

  6. Detection of activated parietal epithelial cells on the glomerular tuft distinguishes early focal segmental glomerulosclerosis from minimal change disease

    NARCIS (Netherlands)

    Smeets, B.; Stucker, F.; Wetzels, J.; Brocheriou, I.; Ronco, P.; Grone, H.J.; D'Agati, V.; Fogo, A.B.; Kuppevelt, T.H. van; Fischer, H.P.; Boor, P.; Floege, J.; Ostendorf, T.; Moeller, M.J.

    2014-01-01

    In rodents, parietal epithelial cells (PECs) migrating onto the glomerular tuft participate in the formation of focal segmental glomerulosclerosis (FSGS) lesions. We investigated whether immunohistologic detection of PEC markers in the initial biopsies of human patients with first manifestation of i

  7. Bilateral calcifications in the basal ganglia, and frontal and parietal lobes of a patient with coeliac disease

    Energy Technology Data Exchange (ETDEWEB)

    Yildirim, Selman Vefa; Tiker, Filiz; Cengiz, Nurcan [Adana Hospital, Department of Paediatrics, Baskent University Medical Faculty, Seyhan-Adana (Turkey); Barutcu, Ozlem [Fatih University Medical Faculty, Radiology Department, Ankara (Turkey)

    2005-07-01

    Previous authors have described a specific syndrome of coeliac disease, bilateral cerebral calcifications and epileptic seizures. We report a 4-year-old boy with coeliac disease who had bilateral calcifications in the basal ganglia and frontal and parietal lobes, but did not exhibit epileptic seizures. (orig.)

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  9. Visuospatial and mathematical dysfunction in major depressive disorder and/or panic disorder: A study of parietal functioning.

    Science.gov (United States)

    Nelson, Brady D; Shankman, Stewart A

    2016-01-01

    The parietal cortex is critical for several different cognitive functions, including visuospatial processing and mathematical abilities. There is strong evidence indicating parietal dysfunction in depression. However, it is less clear whether anxiety is associated with parietal dysfunction and whether comorbid depression and anxiety are associated with greater impairment. The present study compared participants with major depression (MDD), panic disorder (PD), comorbid MDD/PD and controls on neuropsychological measures of visuospatial processing, Judgement of Line Orientation (JLO), and mathematical abilities, Wide Range Achievement Test (WRAT) Arithmetic. Only comorbid MDD/PD was associated with decreased performance on JLO, whereas all psychopathological groups exhibited comparably decreased performance on WRAT Arithmetic. Furthermore, the results were not accounted for by other comorbid disorders, medication use or psychopathology severity. The present study suggests comorbid depression and anxious arousal are associated with impairment in visuospatial processing and provides novel evidence indicating mathematical deficits across depression and/or anxiety. Implications for understanding parietal dysfunction in internalising psychopathology are discussed.

  10. At the Intersection of Attention and Memory: The Mechanistic Role of the Posterior Parietal Lobe in Working Memory

    Science.gov (United States)

    Berryhill, Marian E.; Chein, Jason; Olson, Ingrid R.

    2011-01-01

    Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The "pure storage" hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the "internal attention" hypothesis proposes that the PPC…

  11. The continuous Wagon wheel illusion and the 'when' pathway of the right parietal lobe: a repetitive transcranial magnetic stimulation study.

    Directory of Open Access Journals (Sweden)

    Rufin VanRullen

    Full Text Available A continuous periodic motion stimulus can sometimes be perceived moving in the wrong direction. These illusory reversals have been taken as evidence that part of the motion perception system samples its inputs as a series of discrete snapshots -although other explanations of the phenomenon have been proposed, that rely on the spurious activation of low-level motion detectors in early visual areas. We have hypothesized that the right inferior parietal lobe ('when' pathway plays a critical role in timing perceptual events relative to one another, and thus we examined the role of the right parietal lobe in the generation of this "continuous Wagon Wheel Illusion" (c-WWI. Consistent with our hypothesis, we found that the illusion was effectively weakened following disruption of right, but not left, parietal regions by low frequency repetitive transcranial magnetic stimulation (1 Hz, 10 min. These results were independent of whether the motion stimulus was shown in the left or the right visual field. Thus, the c-WWI appears to depend on higher-order attentional mechanisms that are supported by the 'when' pathway of the right parietal lobe.

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

    Science.gov (United States)

    Yin, Xuntao; Zhao, Lu; Xu, Junhai; Evans, Alan C; Fan, Lingzhong; Ge, Haitao; Tang, Yuchun; Khundrakpam, Budhachandra; Wang, Jian; Liu, Shuwei

    2012-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Magnetoencephalography study of right parietal lobe dysfunction of the evoked mirror neuron system in antipsychotic-free schizophrenia.

    Science.gov (United States)

    Kato, Yutaka; Muramatsu, Taro; Kato, Motoichiro; Shibukawa, Yoshiyuki; Shintani, Masuro; Mimura, Masaru

    2011-01-01

    Patients with schizophrenia commonly exhibit deficits of non-verbal communication in social contexts, which may be related to cognitive dysfunction that impairs recognition of biological motion. Although perception of biological motion is known to be mediated by the mirror neuron system, there have been few empirical studies of this system in patients with schizophrenia. Using magnetoencephalography, we examined whether antipsychotic-free schizophrenia patients displayed mirror neuron system dysfunction during observation of biological motion (jaw movement of another individual). Compared with normal controls, the patients with schizophrenia had fewer components of both the waveform and equivalent current dipole, suggesting aberrant brain activity resulting from dysfunction of the right inferior parietal cortex. They also lacked the changes of alpha band and gamma band oscillation seen in normal controls, and had weaker phase-locking factors and gamma-synchronization predominantly in right parietal cortex. Our findings demonstrate that untreated patients with schizophrenia exhibit aberrant mirror neuron system function based on the right inferior parietal cortex, which is characterized by dysfunction of gamma-synchronization in the right parietal lobe during observation of biological motion.

  15. At the Intersection of Attention and Memory: The Mechanistic Role of the Posterior Parietal Lobe in Working Memory

    Science.gov (United States)

    Berryhill, Marian E.; Chein, Jason; Olson, Ingrid R.

    2011-01-01

    Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The "pure storage" hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the "internal attention" hypothesis proposes that the PPC…

  16. Magnetoencephalography study of right parietal lobe dysfunction of the evoked mirror neuron system in antipsychotic-free schizophrenia.

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    Yutaka Kato

    Full Text Available INTRODUCTION: Patients with schizophrenia commonly exhibit deficits of non-verbal communication in social contexts, which may be related to cognitive dysfunction that impairs recognition of biological motion. Although perception of biological motion is known to be mediated by the mirror neuron system, there have been few empirical studies of this system in patients with schizophrenia. METHODS: Using magnetoencephalography, we examined whether antipsychotic-free schizophrenia patients displayed mirror neuron system dysfunction during observation of biological motion (jaw movement of another individual. RESULTS: Compared with normal controls, the patients with schizophrenia had fewer components of both the waveform and equivalent current dipole, suggesting aberrant brain activity resulting from dysfunction of the right inferior parietal cortex. They also lacked the changes of alpha band and gamma band oscillation seen in normal controls, and had weaker phase-locking factors and gamma-synchronization predominantly in right parietal cortex. CONCLUSIONS: Our findings demonstrate that untreated patients with schizophrenia exhibit aberrant mirror neuron system function based on the right inferior parietal cortex, which is characterized by dysfunction of gamma-synchronization in the right parietal lobe during observation of biological motion.

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  18. CHARACTERIZATION OF DAMAGED MATERIALS

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    Hsu, P C; Dehaven, M; McClelland, M; Chidester, S; Maienschein, J L

    2006-06-23

    Thermal damage experiments were conducted on LX-04, LX-10, and LX-17 at high temperatures. Both pristine and damaged samples were characterized for their material properties. A pycnometer was used to determine sample true density and porosity. Gas permeability was measured in a newly procured system (diffusion permeameter). Burn rate was measured in the LLNL strand burner. Weight losses upon thermal exposure were insignificant. Damaged pressed parts expanded, resulting in a reduction of bulk density by up to 10%. Both gas permeabilities and burn rates of the damaged samples increased by several orders of magnitude due to higher porosity and lower density. Moduli of the damaged materials decreased significantly, an indication that the materials became weaker mechanically. Damaged materials were more sensitive to shock initiation at high temperatures. No significant sensitization was observed when the damaged samples were tested at room temperature.

  19. Genetic Ablation of the ClC-2 Cl- Channel Disrupts Mouse Gastric Parietal Cell Acid Secretion.

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    Meghali P Nighot

    Full Text Available The present studies were designed to examine the effects of ClC-2 ablation on cellular morphology, parietal cell abundance, H/K ATPase expression, parietal cell ultrastructure and acid secretion using WT and ClC-2-/- mouse stomachs. Cellular histology, morphology and proteins were examined using imaging techniques, electron microscopy and western blot. The effect of histamine on the pH of gastric contents was measured. Acid secretion was also measured using methods and secretagogues previously established to give maximal acid secretion and morphological change. Compared to WT, ClC-2-/- gastric mucosal histological organization appeared disrupted, including dilation of gastric glands, shortening of the gastric gland region and disorganization of all cell layers. Parietal cell numbers and H/K ATPase expression were significantly reduced by 34% (P<0.05 and 53% (P<0.001 respectively and cytoplasmic tubulovesicles appeared markedly reduced on electron microscopic evaluation without evidence of canalicular expansion. In WT parietal cells, ClC-2 was apparent in a similar cellular location as the H/K ATPase by immunofluorescence and appeared associated with tubulovesicles by immunogold electron microscopy. Histamine-stimulated [H+] of the gastric contents was significantly (P<0.025 lower by 9.4 fold (89% in the ClC-2-/- mouse compared to WT. Histamine/carbachol stimulated gastric acid secretion was significantly reduced (range 84-95%, P<0.005 in ClC-2-/- compared to WT, while pepsinogen secretion was unaffected. Genetic ablation of ClC-2 resulted in reduced gastric gland region, reduced parietal cell number, reduced H/K ATPase, reduced tubulovesicles and reduced stimulated acid secretion.

  20. Exploring the word superiority effect using TVA

    DEFF Research Database (Denmark)

    Starrfelt, Randi

    Words are made of letters, and yet sometimes it is easier to identify a word than a single letter. This word superiority effect (WSE) has been observed when written stimuli are presented very briefly or degraded by visual noise. It is unclear, however, if this is due to a lower threshold for perc...... simultaneously we find a different pattern: In a whole report experiment with six stimuli (letters or words), letters are perceived more easily than words, and this is reflected both in perceptual processing speed and short term memory capacity....

  1. de educación media superior

    Directory of Open Access Journals (Sweden)

    Enrique Cerón Ferrer

    2007-01-01

    Full Text Available El trabajo presenta los resultados obtenidos en relación al conocimiento y manejo que sobre matemáticas tienen los estudiantes de educación media superior, de los Centros de Estudios Tecnológicos y de Servicios del Distrito Federal, de diferentes carreras que se imparten en estos centros escolares, durante el año 2005. El instrumento de análisis es un cuestionario que contestaron los alumnos, la metodología utilizada es de tipo longitudinal y comparativa.

  2. Activity in right temporo-parietal junction is not selective for theory-of-mind.

    Science.gov (United States)

    Mitchell, Jason P

    2008-02-01

    Recent researchers have suggested that a region of right temporo-parietal junction (RTPJ) selectively subserves the attribution of beliefs to other people (Saxe R, Kanwisher N. 2003. People thinking about thinking people: fMRI investigations of theory of mind. NeuroImage. 19:1835-1842; Saxe R, Powell LJ. 2006. It's the thought that counts: specific brain regions for one component of theory of mind. Psychol Sci. 17:692-699; Saxe R, Wexler A. 2005. Making sense of another mind: the role of the right temporo-parietal junction. Neuropsychologia. 43:1391-1399). At the same time, a similar RTPJ region has been observed repeatedly in a variety of nonsocial tasks that require participants to redirect attention to task-relevant stimuli (e.g., Corbetta M, Shulman GL. 2002. Control of goal-directed and stimulus-driven attention in the brain. Nat Rev Neurosci. 3:201-215; Serences JT, Shomstein S, Leber AB, Golay X, Egeth HE, Yantis S. 2005. Coordination of voluntary and stimulus-driven attentional control in human cortex. Psychol Sci. 16:114-122). However, because these 2 sets of tasks have never been compared within the same participants, it remains unclear whether these observations refer to the exact same region of RTPJ or may instead involve neighboring regions with distinct functional profiles. To test the claim that there is a region of RTPJ selective for belief attribution, the current study used functional neuroimaging to examine the extent to which cortical loci identified by a "theory-of-mind localizer" also distinguish between trials on a target detection task that varied demands to reorient attention (i.e., a version of the "Posner cueing task"). Results were incompatible with claims of RTPJ selectivity for mental state attribution. Regardless of whether regions were defined from group analyses or were individually tailored for each participant, RTPJ activity was also modulated by the nonsocial attentional task. The overlap between theory-of-mind and attentional

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

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    Daselaar, S. M.; Huijbers, W.; Eklund, K.; Moscovitch, M.; Cabeza, R.

    2013-01-01

    In functional neuroimaging studies, ventral parietal cortex (VPC) is recruited by very different cognitive tasks. Explaining the contributions of 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 explained by

  4. Amyloid burden and metabolic function in early-onset Alzheimer's disease: parietal lobe involvement.

    Science.gov (United States)

    Ossenkoppele, Rik; Zwan, Marissa D; Tolboom, Nelleke; van Assema, Danielle M E; Adriaanse, Sofie F; Kloet, Reina W; Boellaard, Ronald; Windhorst, Albert D; Barkhof, Frederik; Lammertsma, Adriaan A; Scheltens, Philip; van der Flier, Wiesje M; van Berckel, Bart N M

    2012-07-01

    Alzheimer's disease with early onset often presents with a distinct cognitive profile, potentially reflecting a different distribution of underlying neuropathology. The purpose of this study was to examine the relationships between age and both in vivo fibrillary amyloid deposition and glucose metabolism in patients with Alzheimer's disease. Dynamic [(11)C]Pittsburgh compound-B (90 min) and static [(18)F]fluorodeoxyglucose (15 min) scans were obtained in 100 patients with Alzheimer's disease and 20 healthy controls. Parametric non-displaceable binding potential images of [(11)C]Pittsburgh compound-B and standardized uptake value ratio images of [(18)F]fluorodeoxyglucose were generated using cerebellar grey matter as reference tissue. Nine [(11)C]Pittsburgh compound-B-negative patients were excluded. The remaining patients were categorized into younger (n=45, age: 56 ± 4 years) and older (n=46, age: 69 ± 5 years) groups, based on the median age (62 years) at time of diagnosis. Younger patients showed more severe impairment on visuo-spatial function, attention and executive function composite scores (Pparietal and occipital and posterior cingulate cortices) as within subjects factor and [(11)C]Pittsburgh compound-B binding/[(18)F]fluorodeoxyglucose uptake as dependent variables. There was no main effect of age for [(11)C]Pittsburgh compound-B or [(18)F]fluorodeoxyglucose, suggesting that overall, the extent of amyloid deposition or glucose hypometabolism did not differ between groups. Regional distributions of [(11)C]Pittsburgh compound-B binding and [(18)F]fluorodeoxyglucose uptake (both P for interaction parietal cortex of younger patients (both Pparietal [(11)C]Pittsburgh compound-B binding for younger patients (standardized β: -0.37) and between visuo-spatial functioning and occipital binding for older patients (standardized β: -0.39). For [(18)F]fluorodeoxyglucose, associations were found between parietal uptake with visuo-spatial (standardized β: 0

  5. Microstructural damage of the posterior corpus callosum contributes to the clinical severity of neglect.

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    Marco Bozzali

    Full Text Available One theory to account for neglect symptoms in patients with right focal damage invokes a release of inhibition of the right parietal cortex over the left parieto-frontal circuits, by disconnection mechanism. This theory is supported by transcranial magnetic stimulation studies showing the existence of asymmetric inhibitory interactions between the left and right posterior parietal cortex, with a right hemispheric advantage. These inhibitory mechanisms are mediated by direct transcallosal projections located in the posterior portions of the corpus callosum. The current study, using diffusion imaging and tract-based spatial statistics (TBSS, aims at assessing, in a data-driven fashion, the contribution of structural disconnection between hemispheres in determining the presence and severity of neglect. Eleven patients with right acute stroke and 11 healthy matched controls underwent MRI at 3T, including diffusion imaging, and T1-weighted volumes. TBSS was modified to account for the presence of the lesion and used to assess the presence and extension of changes in diffusion indices of microscopic white matter integrity in the left hemisphere of patients compared to controls, and to investigate, by correlation analysis, whether this damage might account for the presence and severity of patients' neglect, as assessed by the Behavioural Inattention Test (BIT. None of the patients had any macroscopic abnormality in the left hemisphere; however, 3 cases were discarded due to image artefacts in the MRI data. Conversely, TBSS analysis revealed widespread changes in diffusion indices in most of their left hemisphere tracts, with a predominant involvement of the corpus callosum and its projections on the parietal white matter. A region of association between patients' scores at BIT and brain FA values was found in the posterior part of the corpus callosum. This study strongly supports the hypothesis of a major role of structural disconnection between the

  6. Transcranial direct current stimulation to the parietal cortex in hemispatial neglect : A feasibility study

    NARCIS (Netherlands)

    Smit, Miranda; Schutter, Dennis J L G; Nijboer, Tanja C W; Visser-Meily, Johanna M A; Kappelle, L. Jaap; Kant, Neeltje; Penninx, Janne; Dijkerman, H. Chris

    2015-01-01

    Objectives: Prior research suggests that dampening neural activity of the intact, presumably overactive hemisphere, combined with increasing neural activity in the damaged hemisphere, might restore cortical interhemispheric balance and reduce neglect. In the present study we repeatedly applied a rel

  7. Correlation between white matter damage and gray matter lesions in multiple sclerosis patients

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    Xue-mei Han

    2017-01-01

    Full Text Available We observed the characteristics of white matter fibers and gray matter in multiple sclerosis patients, to identify changes in diffusion tensor imaging fractional anisotropy values following white matter fiber injury. We analyzed the correlation between fractional anisotropy values and changes in whole-brain gray matter volume. The participants included 20 patients with relapsing-remitting multiple sclerosis and 20 healthy volunteers as controls. All subjects underwent head magnetic resonance imaging and diffusion tensor imaging. Our results revealed that fractional anisotropy values decreased and gray matter volumes were reduced in the genu and splenium of corpus callosum, left anterior thalamic radiation, hippocampus, uncinate fasciculus, right corticospinal tract, bilateral cingulate gyri, and inferior longitudinal fasciculus in multiple sclerosis patients. Gray matter volumes were significantly different between the two groups in the right frontal lobe (superior frontal, middle frontal, precentral, and orbital gyri, right parietal lobe (postcentral and inferior parietal gyri, right temporal lobe (caudate nucleus, right occipital lobe (middle occipital gyrus, right insula, right parahippocampal gyrus, and left cingulate gyrus. The voxel sizes of atrophic gray matter positively correlated with fractional anisotropy values in white matter association fibers in the patient group. These findings suggest that white matter fiber bundles are extensively injured in multiple sclerosis patients. The main areas of gray matter atrophy in multiple sclerosis are the frontal lobe, parietal lobe, caudate nucleus, parahippocampal gyrus, and cingulate gyrus. Gray matter atrophy is strongly associated with white matter injury in multiple sclerosis patients, particularly with injury to association fibers.

  8. Pancreaticoduodenectomy with early superior mesenteric artery dissection

    Institute of Scientific and Technical Information of China (English)

    Yu-Fei Xu; Zuo-Jin Liu; Jian-Ping Gong

    2010-01-01

    BACKGROUND: Pancreatic adenocarcinoma remains the fourth leading cause of cancer-related death and is one of the most aggressive human tumors. At present, surgical resection is the only potentially curative treatment. Early neck division is inadequate when invasion of the superior mesenteric artery (SMA) is suspected or in cases of replaced or accessory right hepatic artery. Malignant periampullary tumors often invade retroperitoneal peripancreatic tissues and a positive resection margin is associated with a poor long-term survival. DATA SOURCES: English-language medical databases, PubMed, ELSEVIER and SPRINGERLINK, were searched for articles on"posterior approach pancreaticoduodenectomy","superior mesenteric artery ifrst approach", "retroperitoneal tissue","hanging maneuver", and related topics. RESULTS:The modiifcation allowed the surgeon to early identify the nonresectability of a replaced right hepatic artery if present, enabling complete dissection of the right side of the SMA and portal vein as well as complete excision of the retroportal pancreatic lamina. CONCLUSION: Pancreaticoduodenectomy with early retro-pancreatic dissection is a useful and safe technical variant, which is indicated for the improvement of the safety and curative effect of the procedure.

  9. Radiation treatment of superior sulcus lung carcinoma

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    Millar, J.; Ball, D.; Worotniuk, V.; Smith, J.; Crennan, E.; Bishop, M. [Peter MacCallum Cancer Inst., East Melbourne, VIC (Australia)

    1996-02-01

    The survival of patients with superior sulcus lung carcinoma and the effects of treatment were reviewed. From a prospective database of 4123 consecutive new patients with lung carcinoma, 131 (3.2%) cases of superior sulcus lung carcinoma were identified. Seventy-four patients were planned to receive radiation with palliative intent, 53 radical radiotherapy and one was observed only. The remaining three patients, with small-cell carcinoma, were treated with chemotherapy with or without radiotherapy. Of the 53 radically treated patients, nine were treated with pre-operative radiation prior to intended radical resection. Analysis was carried out on the effect on survival of performance status, nodal involvement, weight loss, vertebral body or rib involvement, treatment intent and radical combined modality treatment compared with radical radiation alone. The estimated median survival for the whole group was 7.6 months; for those treated radically it was 18.3 months, while for the palliatively treated patients it was 3.7 months. Radically treated patients with no initial nodal involvement had an estimated median survival of 22 months, while radically treated patients with nodal involvement had an estimated median survival of 8.4 months (P = 0.003). There were no statistically significant differences in survival between radically treated patients grouped according to initial weight loss, performance status, or vertebral body and rib involvement. Patients treated with pre-operative radiation did not survive significantly longer than patients treated with radiation alone, although the numbers are small. 33 refs., 2 tabs., 4 figs.

  10. Studies on zooplankton of Lago Paione Superiore

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    Patrizia COMOLI

    1999-08-01

    Full Text Available We report here the results of a three year study on the zooplankton of Lago Paione Superiore, an acid sensitive lake above the tree line in the Italian Alps. The research was carried out within MOLAR, an EC-founded Project on “Measuring and Modeling the dynamic response of remote mountain lakes ecosystems to environmental change”. This study comes after a series of investigations on the effects of acidification, in which we documented the changes occurred with decreasing water pHs, by comparing the recent situation with that in the literature of the 40s, and reconstructed the beginning of anthropogenic disturbance through an analysis of the past cladocera assemblages archived in the lake sediments. A characteristic pattern in seasonal periodicity is a transition from a community dominated by small zooplankton (August to a community where the large particle-feeder Daphnia longispina dominates. This is a typical pattern observed in fishless, copepod-cladocera lakes. Regardless from which food is able to exploit, Daphnia population of Lago Paione Superiore is composed by well-fed organisms, visually rich in lipids, able to produce more than one generation/ year of parthenogenetic females at density levels which are rather high in an oligotrophic high mountain lake.

  11. Parietal plasticity after training with a complex video game is associated with individual differences in improvements in an untrained working memory task

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    Aki eNikolaidis

    2014-03-01

    Full Text Available Researchers have devoted considerable attention and resources to cognitive training, yet there have been few examinations of the relationship between individual differences in patterns of brain activity during the training task and training benefits on untrained tasks (i.e., transfer. While a predominant hypothesis suggests that training will transfer if there is training-induced plasticity in brain regions important for the untrained task, this theory lacks sufficient empirical support. To address this issue we investigated the relationship between individual differences in training-induced changes in brain activity during a cognitive training videogame, and whether those changes explained individual differences in the resulting changes in performance in untrained tasks. Forty-five young adults trained with a videogame that challenges working memory, attention, and motor control for 15 2-hour sessions. Before and after training, all subjects received neuropsychological assessments targeting working memory, attention, and procedural learning to assess transfer. Subjects also underwent pre and post functional magnetic resonance imaging (fMRI scans while they played the training videogame to assess how these patterns of brain activity change in response to training. For regions implicated in working memory, such as the superior parietal lobe, individual differences in the post-minus-pre changes in activation predicted performance changes in an untrained working memory task. These findings suggest that training-induced plasticity in the functional representation of a training task may play a role in individual differences in transfer. Our data support and extend previous literature that has examined the association between training related cognitive changes and associated changes in underlying neural networks. We discuss the role of individual differences in brain function in training generalizability and make suggestions for future cognitive

  12. Cochlear implant outcomes in patients with superior canal dehiscence

    NARCIS (Netherlands)

    Puram, Sidharth V.; Roberts, Daniel S.; Niesten, Marlien E F; Dilger, Amanda E.; Lee, Daniel J.

    2015-01-01

    Objective: To determine whether adult cochlear implant (CI) users with superior canal dehiscence syndrome (SCDS) or asymptomatic superior semicircular canal dehiscence (SCD) have different surgical, vestibular, and audiologic outcomes when compared to CI users with normal temporal bone anatomy. Meth

  13. Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.

    Science.gov (United States)

    Zhang, Ying; Whitfield-Gabrieli, Susan; Christodoulou, Joanna A; Gabrieli, John D E

    2013-01-01

    Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow's direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading.

  14. Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    Full Text Available Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI to examine brain activation while adults with or without dyslexia responded to the change of an arrow's direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading.

  15. 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.

  16. Neurophysiology of prehension. III. Representation of object features in posterior parietal cortex of the macaque monkey.

    Science.gov (United States)

    Gardner, Esther P; Babu, K Srinivasa; Ghosh, Soumya; Sherwood, Adam; Chen, Jessie

    2007-12-01

    Neurons in posterior parietal cortex (PPC) may serve both proprioceptive and exteroceptive functions during prehension, signaling hand actions and object properties. To assess these roles, we used digital video recordings to analyze responses of 83 hand-manipulation neurons in area 5 as monkeys grasped and lifted objects that differed in shape (round and rectangular), size (large and small spheres), and location (identical rectangular blocks placed lateral and medial to the shoulder). The task contained seven stages -- approach, contact, grasp, lift, hold, lower, relax -- plus a pretrial interval. The four test objects evoked similar spike trains and mean rate profiles that rose significantly above baseline from approach through lift, with peak activity at contact. Although representation by the spike train of specific hand actions was stronger than distinctions between grasped objects, 34% of these neurons showed statistically significant effects of object properties or hand postures on firing rates. Somatosensory input from the hand played an important role as firing rates diverged most prominently on contact as grasp was secured. The small sphere -- grasped with the most flexed hand posture -- evoked the highest firing rates in 43% of the population. Twenty-one percent distinguished spheres that differed in size and weight, and 14% discriminated spheres from rectangular blocks. Location in the workspace modulated response amplitude as objects placed across the midline evoked higher firing rates than positions lateral to the shoulder. We conclude that area 5 neurons, like those in area AIP, integrate object features, hand actions, and grasp postures during prehension.

  17. Commonalities for numerical and continuous quantity skills at temporo-parietal junction.

    Science.gov (United States)

    Cappelletti, Marinella; Chamberlain, Rebecca; Freeman, Elliot D; Kanai, Ryota; Butterworth, Brian; Price, Cathy J; Rees, Geraint

    2014-05-01

    How do our abilities to process number and other continuous quantities such as time and space relate to each other? Recent evidence suggests that these abilities share common magnitude processing and neural resources, although other findings also highlight the role of dimension-specific processes. To further characterize the relation between number, time, and space, we first examined them in a population with a developmental numerical dysfunction (developmental dyscalculia) and then assessed the extent to which these abilities correlated both behaviorally and anatomically in numerically normal participants. We found that (1) participants with dyscalculia showed preserved continuous quantity processing and (2) in numerically normal adults, numerical and continuous quantity abilities were at least partially dissociated both behaviorally and anatomically. Specifically, gray matter volume correlated with both measures of numerical and continuous quantity processing in the right TPJ; in contrast, individual differences in number proficiency were associated with gray matter volume in number-specific cortical regions in the right parietal lobe. Together, our new converging evidence of selective numerical impairment and of number-specific brain areas at least partially distinct from common magnitude areas suggests that the human brain is equipped with different ways of quantifying the outside world.

  18. The critical roles of localization and physiology for understanding parietal contributions to memory retrieval.

    Science.gov (United States)

    Nelson, Steven M; McDermott, Kathleen B; Wig, Gagan S; Schlaggar, Bradley L; Petersen, Steven E

    2013-12-01

    Functional magnetic resonance imaging (fMRI) studies of recognition memory ubiquitously demonstrate retrieval-related activity in left lateral parietal cortex (LLPC) when contrasting studied ("old") items with unstudied ("new") items. Recent work demonstrates that there is considerable functional-anatomical heterogeneity in LLPC. One implication of this observation is that single- or dual-process models fall short of characterizing LLPC contributions to memory retrieval. Instead of considering LLPC as a single entity, functional accounts must be given for each of the distinct regions that show retrieval-related effects; we posit there are a minimum of four such regions and very likely more. Identification of these LLPC regions requires careful analysis to map the boundaries and the extent of the regions precisely. In addition, characterizing the functional responses as activations or deactivations relative to baseline will be crucial in understanding the underlying cognitive processes. Considering LLPC in both memory and "nonmemory" domains will also illuminate the contribution of these regions, because it is certainly unlikely they serve only the domain of memory retrieval.

  19. 1 Hz rTMS of the left posterior parietal cortex (PPC) modifies sensorimotor timing

    Science.gov (United States)

    Krause, Vanessa; Bashir, Shahid; Pollok, Bettina; Caipa, Anuhya; Schnitzler, Alfons; Pascual-Leone, Alvaro

    2013-01-01

    In order to investigate the relevance of the left posterior parietal cortex (PPC) for precise sensorimotor timing we applied 1 Hz repetitive transcranial magnetic stimulation (rTMS) over left PPC, right PPC and visual cortex of healthy participants for ten minutes, respectively. The impact on sensorimotor timing of the right hand was assessed using a synchronization task that required subjects to synchronize their right index finger taps with respect to constant auditory, visual or auditory-visual pacing. Our results reveal reduced negative tap-to-pacer asynchronies following rTMS of the left PPC in all pacing conditions. This effect lasted for about 5 minutes after cessation of rTMS. Right PPC and visual cortex stimulation did not yield any significant behavioural effects. Since suppression of left PPC modified right-hand synchronization accuracy independent of the pacing signal’s modality, the present data support the significance of left PPC for anticipatory motor control over a primary role in multisensory integration. The present data suggest that 1 Hz rTMS might interrupt a matching process of anticipated and real sensorimotor feedback within PPC. Alternatively, downregulation of left PPC activity may affect M1 excitability via functional connections leading to a delay in motor output and, thus, smaller tap-to-pacer asynchronies. PMID:23103789