The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Simon B. Eickhoff - One of the best experts on this subject based on the ideXlab platform.
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meta analytical definition and functional connectivity of the human vestibular cortex
NeuroImage, 2012Co-Authors: Zu P Eulenburg, Svenja Caspers, Christian Roski, Simon B. EickhoffAbstract:Contrary to most other sensory systems, no consensus has been reached within the scientific community about the exact locations and functions of human cortical areas processing vestibular information. Metaanalytical modelling using activation likelihood estimation (ALE) for the integration of neuroimaging results has already been successfully applied to several distinct tasks, thereby revealing the cortical localization of cognitive functions. We used the same algorithm and technique with all available and suitable PET and fMRI studies employing a vestibular stimulus. Most consistently across 28 experiments vestibular stimuli evoked activity in the right hemispheric Parietal opercular area OP 2 implicating it as the core region for vestibular processing. Furthermore, we took our primary results as a seeding point and fed them into a functional connectivity analysis based on resting-state oscillations in 100 healthy subjects. This subsequent calculation confirmed direct connections of the area OP 2 with every other region found in the meta-analysis, in particular temporo-Parietal regions, premotor cortex, and the midcingulate gyrus. Thus revealing a joint vestibular network in accordance with a concept from animal literature termed the inner vestibular circle. Moreover, there was also a significant vestibular connectivity overlap with frontal but not Parietal cortical centres responsible for the generation of saccadic eye movements, likely to be involved in nystagmus fast phase generation. This was shown in an additional ocular motor meta-analysis. We conclude that the cytoarchitectonic area OP 2 in the Parietal Operculum, embedded in a joint vestibular network, should be the primary candidate for the human vestibular cortex. This area may represent the human homologue to the vestibular area PIVC as proposed by Guldin and Grusser in non-human primates.
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anatomical and functional connectivity of cytoarchitectonic areas within the human Parietal Operculum
The Journal of Neuroscience, 2010Co-Authors: Simon B. Eickhoff, Karl Zilles, Svenja Caspers, Saad Jbabdi, Angela R Laird, Peter T Fox, Timothy E J BehrensAbstract:In monkeys, the somatosensory cortex on the Parietal Operculum can be differentiated into several distinct cortical fields. Potential human homologues for these areas have already been defined by cytoarchitectonic mapping and functional imaging experiments. Differences between the two most widely studied areas [Operculum Parietale (OP) 1 and OP 4] within this region particularly pertain to their connection with either the perceptive Parietal network or the frontal motor areas. In the present study, we investigated differences in anatomical connection patterns probed by probabilistic tractography on diffusion tensor imaging data. Functional connectivity was then mapped by coordinate-based meta-analysis of imaging studies. Comparison between these two aspects of connectivity showed a good congruency and hence converging evidence for an involvement of these areas in matching brain networks. There were, however, also several instances in which anatomical and functional connectivity diverged, underlining the independence of these measures and the need for multimodal characterization of brain connectivity. The connectivity analyses performed showed that the two largest areas within the human Parietal Operculum region display considerable differences in their connectivity to frontoParietal brain regions. In particular, relative to OP 1, area OP 4 is more closely integrated with areas responsible for basic sensorimotor processing and action control, while OP 1 is more closely connected to the Parietal networks for higher order somatosensory processing. These results are largely congruent with data on nonhuman primates. Differences between anatomical and functional connectivity as well as between species, however, highlight the need for an integrative view on connectivity, including comparison and cross-validation of results from different approaches.
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effects of low frequency repetitive transcranial magnetic stimulation of the contralesional primary motor cortex on movement kinematics and neural activity in subcortical stroke
JAMA Neurology, 2008Co-Authors: Dennis A Nowak, Christian Grefkes, Simon B. Eickhoff, Manuel Dafotakis, Jutta Kust, H Karbe, Gereon R. FinkAbstract:Objective: To determine the effects of 1-Hz repetitive transcranial magnetic stimulation (rTMS) of the contralesional M1 on movement kinematics and neural activation within the motor system in the subacute phase after subcortical stroke. Design: Crossover investigation. Setting: A university hospital. Methods: Fifteen right-handed patients with impaired dexterityduetosubcorticalmiddlecerebralarterystroke received 1-Hz rTMS for 10 minutes applied to the vertex (control stimulation) and contralesional M1. For behavioral testing, patients performed finger and grasp movementswithbothhandsat2baselineconditions,separated by 1 week, and following each rTMS application. Forfunctionalmagneticresonanceimaging,patientsperformed hand grip movements with their affected or unaffected hand before and after each rTMS application. Results: Application of rTMS to the contralesional M1 improved the kinematics of finger and grasp movements in the affected hand. At the neural level, rTMS appliedtothecontralesionalM1reducedoveractivityinthe contralesionalprimaryandnonprimarymotorareas.There was no significant correlation between the rTMSinduced reduction in blood oxygen level–dependent responses within the contralesional M1 and the degree of behavioral improvement of the affected hand. Overactivity of the contralesional dorsal premotor cortex, contralesional Parietal Operculum, and ipsilesional mesial frontalcortexatbaselinepredictedimprovementofmovementkinematicswiththeaffectedhandafterrTMSofthe contralesional M1.
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the somatotopic organization of cytoarchitectonic areas on the human Parietal Operculum
Cerebral Cortex, 2007Co-Authors: Christian Grefkes, Karl Zilles, Simon B. Eickhoff, Gereon R. FinkAbstract:The secondary somatosensory cortex (SII) of nonhuman primates is located on the Parietal Operculum. In the monkey, electrophysiological and connectivity tracing studies as well as histological investigations provide converging evidence for 3 distinct cortical areas (SII, PV, and VS) within this region, each of which contains a complete somatotopic map. Although the equivalency of the Parietal Operculum as the location of SII between humans and nonhuman primates is undisputed, the internal organization of the human SII region is still largely unknown. Based on their topography, we have previously argued that the cytoarchitectonic areas OP 1, OP 4, and OP 3 may constitute the human homologues of areas SII, PV, and VS, respectively. To test this hypothesis, we here examined (using functional magnetic resonance imaging) the somatotopic organization of the human Parietal Operculum by applying tactile stimulation to the skin at 4 different locations on either side of the body (face, hands, trunk, and legs). The locations of the resulting activation foci were then compared with the cytoarchitectonic maps of this region. Data analysis revealed 2 somatotopic body representations on the lateral Operculum in areas OP 1 and OP 4. The functional border between these 2 body maps was defined by a mirror reversal in the somatotopic arrangement and coincided with the cytoarchitectonically defined border between these 2 areas. This somatotopic arrangement closely matches that described for SII and PV in nonhuman primates. The data also suggested a third somatotopic map located deeper inside the Sylvian fissure in area OP 3. Based on the observed topographic arrangement and their functional response characteristics, we conclude that cytoarchitectonic areas OP1, OP 4, and OP 3 on the human Parietal Operculum constitute the human homologues of primate areas SII, PV, and VS, respectively.
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the human Parietal Operculum i cytoarchitectonic mapping of subdivisions
Cerebral Cortex, 2006Co-Authors: Simon B. Eickhoff, Karl Zilles, Axel Schleicher, Katrin AmuntsAbstract:The human secondary somatosensory cortex (SII) is located on the Parietal Operculum, as shown by intraoperative stimulation and functional imaging studies. The position and extent of the anatomical correlates of this functionally defined region, however, are still unknown. We have therefore histologically mapped the putative anatomical correlates of the SII cortex in cell-body-stained histological sections of 10 human postmortem brains using quantitative cytoarchitectonic analysis. The gray level index (GLI), which is an indicator of the volume fraction of nerve cell bodies, was measured in the Parietal Operculum. GLI profiles as measures of the laminar pattern of the cortex were extracted perpendicular to cortical layers. Cytoarchitectonic borders were detected observerindependently by multivariate statistical analysis of the laminar profiles. Four cytoarchitectonic areas (termed OP 1--4) were identified. This cytoarchitectonic heterogeneity of the Parietal Operculum corresponds to results of functional imaging studies on the human SII cortex and data from non-human primates where multiple subregions within SII have been demonstrated by electrophysiological and connectivity studies.
Karl Zilles - One of the best experts on this subject based on the ideXlab platform.
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anatomical and functional connectivity of cytoarchitectonic areas within the human Parietal Operculum
The Journal of Neuroscience, 2010Co-Authors: Simon B. Eickhoff, Karl Zilles, Svenja Caspers, Saad Jbabdi, Angela R Laird, Peter T Fox, Timothy E J BehrensAbstract:In monkeys, the somatosensory cortex on the Parietal Operculum can be differentiated into several distinct cortical fields. Potential human homologues for these areas have already been defined by cytoarchitectonic mapping and functional imaging experiments. Differences between the two most widely studied areas [Operculum Parietale (OP) 1 and OP 4] within this region particularly pertain to their connection with either the perceptive Parietal network or the frontal motor areas. In the present study, we investigated differences in anatomical connection patterns probed by probabilistic tractography on diffusion tensor imaging data. Functional connectivity was then mapped by coordinate-based meta-analysis of imaging studies. Comparison between these two aspects of connectivity showed a good congruency and hence converging evidence for an involvement of these areas in matching brain networks. There were, however, also several instances in which anatomical and functional connectivity diverged, underlining the independence of these measures and the need for multimodal characterization of brain connectivity. The connectivity analyses performed showed that the two largest areas within the human Parietal Operculum region display considerable differences in their connectivity to frontoParietal brain regions. In particular, relative to OP 1, area OP 4 is more closely integrated with areas responsible for basic sensorimotor processing and action control, while OP 1 is more closely connected to the Parietal networks for higher order somatosensory processing. These results are largely congruent with data on nonhuman primates. Differences between anatomical and functional connectivity as well as between species, however, highlight the need for an integrative view on connectivity, including comparison and cross-validation of results from different approaches.
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the somatotopic organization of cytoarchitectonic areas on the human Parietal Operculum
Cerebral Cortex, 2007Co-Authors: Christian Grefkes, Karl Zilles, Simon B. Eickhoff, Gereon R. FinkAbstract:The secondary somatosensory cortex (SII) of nonhuman primates is located on the Parietal Operculum. In the monkey, electrophysiological and connectivity tracing studies as well as histological investigations provide converging evidence for 3 distinct cortical areas (SII, PV, and VS) within this region, each of which contains a complete somatotopic map. Although the equivalency of the Parietal Operculum as the location of SII between humans and nonhuman primates is undisputed, the internal organization of the human SII region is still largely unknown. Based on their topography, we have previously argued that the cytoarchitectonic areas OP 1, OP 4, and OP 3 may constitute the human homologues of areas SII, PV, and VS, respectively. To test this hypothesis, we here examined (using functional magnetic resonance imaging) the somatotopic organization of the human Parietal Operculum by applying tactile stimulation to the skin at 4 different locations on either side of the body (face, hands, trunk, and legs). The locations of the resulting activation foci were then compared with the cytoarchitectonic maps of this region. Data analysis revealed 2 somatotopic body representations on the lateral Operculum in areas OP 1 and OP 4. The functional border between these 2 body maps was defined by a mirror reversal in the somatotopic arrangement and coincided with the cytoarchitectonically defined border between these 2 areas. This somatotopic arrangement closely matches that described for SII and PV in nonhuman primates. The data also suggested a third somatotopic map located deeper inside the Sylvian fissure in area OP 3. Based on the observed topographic arrangement and their functional response characteristics, we conclude that cytoarchitectonic areas OP1, OP 4, and OP 3 on the human Parietal Operculum constitute the human homologues of primate areas SII, PV, and VS, respectively.
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the human Parietal Operculum i cytoarchitectonic mapping of subdivisions
Cerebral Cortex, 2006Co-Authors: Simon B. Eickhoff, Karl Zilles, Axel Schleicher, Katrin AmuntsAbstract:The human secondary somatosensory cortex (SII) is located on the Parietal Operculum, as shown by intraoperative stimulation and functional imaging studies. The position and extent of the anatomical correlates of this functionally defined region, however, are still unknown. We have therefore histologically mapped the putative anatomical correlates of the SII cortex in cell-body-stained histological sections of 10 human postmortem brains using quantitative cytoarchitectonic analysis. The gray level index (GLI), which is an indicator of the volume fraction of nerve cell bodies, was measured in the Parietal Operculum. GLI profiles as measures of the laminar pattern of the cortex were extracted perpendicular to cortical layers. Cytoarchitectonic borders were detected observerindependently by multivariate statistical analysis of the laminar profiles. Four cytoarchitectonic areas (termed OP 1--4) were identified. This cytoarchitectonic heterogeneity of the Parietal Operculum corresponds to results of functional imaging studies on the human SII cortex and data from non-human primates where multiple subregions within SII have been demonstrated by electrophysiological and connectivity studies.
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the human Parietal Operculum ii stereotaxic maps and correlation with functional imaging results
Cerebral Cortex, 2006Co-Authors: Simon B. Eickhoff, Katrin Amunts, Hartmut Mohlberg, Karl ZillesAbstract:In this study we describe the localization of the cytoarchitectonic subdivisions of the human Parietal Operculum in stereotaxic space and relate these anatomically defined cortical areas to the location of the functionally defined secondary somatosensory cortex (SII cortex) using a meta-analysis of functional imaging results. The human Parietal Operculum consists of four distinct cytoarchitectonic areas (OP 1-4) as shown in the preceding publication. The 10 cytoarchitectonically examined brains were 3-D-reconstructed and spatially normalized to the T1-weighted single-subject template of the Montreal Neurological Institute (MNI). A probabilistic map was calculated for each area in this standard stereotaxic space. A cytoarchitectonic summary map of the four cortical areas on the human Parietal Operculum which combines these probabilistic maps was subsequently computed for the comparison with a meta-analysis of functional locations of SII. The meta-analysis used the results from 57 fMRI and PET studies and allowed the comparison of the functionally defined SII region to the cytoarchitectonic map of the Parietal Operculum. The functional localization of SII showed a good match to the cytoarchitectonically defined region. Therefore the cytoarchitectonic maps of OP 1-4 of the human Parietal Operculum can be interpreted as an anatomical correlate of the (functionally defined) human SII region. Our results also suggest that the SII foci reported in functional imaging studies may actually reflect activations in either of its architectonic subregions.
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Identifying human parieto-insular vestibular cortex using fMRI and cytoarchitectonic mapping.
Human brain mapping, 2006Co-Authors: Simon B. Eickhoff, Peter H. Weiss, Katrin Amunts, Gereon R. Fink, Karl ZillesAbstract:The parieto-insular vestibular cortex (PIVC) plays a central role in the cortical vestibular network. Although this region was first defined and subsequently extensively studied in nonhuman primates, there is also ample evidence for a human analogue in the posterior Parietal Operculum. In this study, we functionally and anatomically characterize the putative human equivalent to macaque area PIVC by combining functional magnetic resonance imaging (fMRI) of the cortical response to galvanic vestibular stimulation (GVS) with probabilistic cytoarchitectonic maps of the human Parietal Operculum. Our fMRI data revealed a bilateral cortical response to GVS in posterior parieto-insular cortex. Based on the topographic similarity of these activations to primate area PIVC, we suggest that they constitute the functionally defined human equivalent to macaque area PIVC. The locations of these activations were then compared to the probabilistic cytoarchitectonic maps of the Parietal Operculum (Eickhoff et al. [2005a]: Cereb Cortex, in press; Eickhoff et al. [2005c]: Cereb Cortex, in press), whereby the functionally defined PIVC matched most closely the cytoarchitectonically defined area OP 2. This activation of OP 2 by vestibular stimulation and its cytoarchitectonic features, which are similar to other primary sensory areas, suggest that area OP 2 constitutes the human equivalent of macaque area PIVC.
Marianne Dieterich - One of the best experts on this subject based on the ideXlab platform.
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the Parietal lobe and the vestibular system
Handbook of Clinical Neurology, 2018Co-Authors: Marianne Dieterich, Thomas BrandtAbstract:Abstract The vestibular cortex differs in various ways from other sensory cortices. It consists of a network of several distinct and separate temporoParietal areas. Its core region, the parietoinsular vestibular cortex (PIVC), is located in the posterior insula and retroinsular region and includes the Parietal Operculum. The entire network is multisensory (in particular, vestibular, visual, and somatosensory). The peripheral and central vestibular systems are bilaterally organized; there are various pontomesencephalic brainstem crossings and at least two transcallosal connections of both hemispheres, between the PIVC and the motion-sensitive visual cortex areas, which also mediate vestibular input. Structural and functional vestibular dominance characterizes the right hemisphere in right-handers and the left hemisphere in left-handers. This explains why right-hemispheric lesions in right-handers more often generally cause hemispatial neglect and the pusher syndrome, both of which involve vestibular function. Vestibular input also contributes to cognition and may determine individual lateralization of brain functions such as handedness. Bilateral organization is a major key to understanding cortical functions and disorders, for example, the visual–vestibular interaction that occurs in spatial orientation. Although the vestibular cortex is represented in both hemispheres, there is only one global percept of body position and motion. The chiefly vestibular aspects of the multiple functions and disorders of the Parietal lobe dealt with in this chapter cannot be strictly separated from various multisensory vestibular functions within the entire brain.
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recovery from spatial neglect with intra and transhemispheric functional connectivity changes in vestibular and visual cortex areas a case study
Frontiers in Neurology, 2018Co-Authors: Julian Conrad, Thomas Brandt, Rainer Boegle, Matthias Ertl, Marianne DieterichAbstract:Objective: Vestibular signals are involved in higher cortical functions like spatial orientation and its disorders. Vestibular dysfunction contributes, for example, to spatial neglect which can be transiently improved by caloric stimulation. The exact roles and mechanisms of the vestibular and visual systems for the recovery of neglect is not yet known. Methods: Resting state functional connectivity (fc) MRI was recorded in a patient with hemispatial neglect during the acute phase and after recovery six months later following a right MCA infarction before and after caloric vestibular stimulation. Seeds in the vestibular (Parietal Operculum OP2), the Parietal (PPC; 7A, hIP3), and the visual cortex were used for the analysis. Results: During the acute stage after caloric stimulation the fc of the right OP2 to the left OP2, the anterior cingulum, and the para/hippocampus was increased bilaterally (i.e., the vestibular network), while the interhemispheric fc was reduced between homologous regions in the visual cortex (VC). After six months similar fc increases in the vestibular network were found without stimulation. In addition, fc increases of the OP2 to the PPC and the VC were seen; interhemispherically this was true for both PPCs and for the right PPC to both VCs. Conclusion: Improvement of neglect after caloric stimulation in the acute phase was associated with increased fc of vestibular cortex areas in both hemispheres to the para-hippocampus and the dorsal anterior cingulum, but simultaneously with reduced interhemispheric VC connectivity. This disclosed a, to some extent, similar but also distinct short-term mechanism (vestibular stimulation) of an improvement of spatial orientation compared to the long-term recovery of neglect.
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2018Co-Authors: Julian Conrad, Thomas Brandt, Rainer Boegle, Matthias Ertl, Marianne DieterichAbstract:ObjectiveVestibular signals are involved in higher cortical functions like spatial orientation and its disorders. Vestibular dysfunction contributes, for example, to spatial neglect which can be transiently improved by caloric stimulation. The exact roles and mechanisms of the vestibular and visual systems for the recovery of neglect are not yet known.MethodsResting-state functional connectivity (fc) magnetic resonance imaging was recorded in a patient with hemispatial neglect during the acute phase and after recovery 6 months later following a right middle cerebral artery infarction before and after caloric vestibular stimulation. Seeds in the vestibular [Parietal Operculum (OP2)], the Parietal [posterior Parietal cortex (PPC); 7A, hIP3], and the visual cortex (VC) were used for the analysis.ResultsDuring the acute stage after caloric stimulation the fc of the right OP2 to the left OP2, the anterior cingulum, and the para/hippocampus was increased bilaterally (i.e., the vestibular network), while the interhemispheric fc was reduced between homologous regions in the VC. After 6 months, similar fc increases in the vestibular network were found without stimulation. In addition, fc increases of the OP2 to the PPC and the VC were seen; interhemispherically this was true for both PPCs and for the right PPC to both VCs.ConclusionImprovement of neglect after caloric stimulation in the acute phase was associated with increased fc of vestibular cortex areas in both hemispheres to the para-hippocampus and the dorsal anterior cingulum, but simultaneously with reduced interhemispheric VC connectivity. This disclosed a, to some extent, similar but also distinct short-term mechanism (vestibular stimulation) of an improvement of spatial orientation compared to the long-term recovery of neglect.
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interoceptive and multimodal functions of the operculo insular cortex tactile nociceptive and vestibular representations
NeuroImage, 2013Co-Authors: Zu P Eulenburg, Ulf Baumgartner, Rolfdetlef Treede, Marianne DieterichAbstract:The operculo-insular cortex has been termed the 'homeostatic control center' or 'general magnitude estimator' of the human mind. In this study, somatosensory, nociceptive and caloric vestibular stimuli were applied to reveal, whether there are mainly common, or possibly specific regions activated by one modality alone and whether lateralization effects, time pattern differences or influences of the aversive nature of the stimuli could be observed. Activation of the dorsal posterior insula was caused by all stimuli alike thus terming this area multimodal. Early phases of the noxious heat and caloric vestibular stimulation led to responses in the anterior insula. Using conjunction analyses we found that left- and right-sided tactile stimulation, but not nociceptive stimulation, caused a joint activation of the cytoarchitectonic area OP1 and nociceptive but not tactile stimulation of the anterior insula bilaterally. Tactile activation in the Parietal Operculum (SII, OP1) was distinct from nociceptive activation (OP3 and frontal Operculum). The joint activation by all three stimuli located in the dorsal posterior insula argues for the presence of multisensory structures. The distinct activation of the anterior insula by aversive stimuli and the posterior insula by multisensory signals supports the concept of a partitioned insular cortex recently introduced based on connectivity studies and meta-analyses.
Gereon R. Fink - One of the best experts on this subject based on the ideXlab platform.
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effects of low frequency repetitive transcranial magnetic stimulation of the contralesional primary motor cortex on movement kinematics and neural activity in subcortical stroke
JAMA Neurology, 2008Co-Authors: Dennis A Nowak, Christian Grefkes, Simon B. Eickhoff, Manuel Dafotakis, Jutta Kust, H Karbe, Gereon R. FinkAbstract:Objective: To determine the effects of 1-Hz repetitive transcranial magnetic stimulation (rTMS) of the contralesional M1 on movement kinematics and neural activation within the motor system in the subacute phase after subcortical stroke. Design: Crossover investigation. Setting: A university hospital. Methods: Fifteen right-handed patients with impaired dexterityduetosubcorticalmiddlecerebralarterystroke received 1-Hz rTMS for 10 minutes applied to the vertex (control stimulation) and contralesional M1. For behavioral testing, patients performed finger and grasp movementswithbothhandsat2baselineconditions,separated by 1 week, and following each rTMS application. Forfunctionalmagneticresonanceimaging,patientsperformed hand grip movements with their affected or unaffected hand before and after each rTMS application. Results: Application of rTMS to the contralesional M1 improved the kinematics of finger and grasp movements in the affected hand. At the neural level, rTMS appliedtothecontralesionalM1reducedoveractivityinthe contralesionalprimaryandnonprimarymotorareas.There was no significant correlation between the rTMSinduced reduction in blood oxygen level–dependent responses within the contralesional M1 and the degree of behavioral improvement of the affected hand. Overactivity of the contralesional dorsal premotor cortex, contralesional Parietal Operculum, and ipsilesional mesial frontalcortexatbaselinepredictedimprovementofmovementkinematicswiththeaffectedhandafterrTMSofthe contralesional M1.
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the somatotopic organization of cytoarchitectonic areas on the human Parietal Operculum
Cerebral Cortex, 2007Co-Authors: Christian Grefkes, Karl Zilles, Simon B. Eickhoff, Gereon R. FinkAbstract:The secondary somatosensory cortex (SII) of nonhuman primates is located on the Parietal Operculum. In the monkey, electrophysiological and connectivity tracing studies as well as histological investigations provide converging evidence for 3 distinct cortical areas (SII, PV, and VS) within this region, each of which contains a complete somatotopic map. Although the equivalency of the Parietal Operculum as the location of SII between humans and nonhuman primates is undisputed, the internal organization of the human SII region is still largely unknown. Based on their topography, we have previously argued that the cytoarchitectonic areas OP 1, OP 4, and OP 3 may constitute the human homologues of areas SII, PV, and VS, respectively. To test this hypothesis, we here examined (using functional magnetic resonance imaging) the somatotopic organization of the human Parietal Operculum by applying tactile stimulation to the skin at 4 different locations on either side of the body (face, hands, trunk, and legs). The locations of the resulting activation foci were then compared with the cytoarchitectonic maps of this region. Data analysis revealed 2 somatotopic body representations on the lateral Operculum in areas OP 1 and OP 4. The functional border between these 2 body maps was defined by a mirror reversal in the somatotopic arrangement and coincided with the cytoarchitectonically defined border between these 2 areas. This somatotopic arrangement closely matches that described for SII and PV in nonhuman primates. The data also suggested a third somatotopic map located deeper inside the Sylvian fissure in area OP 3. Based on the observed topographic arrangement and their functional response characteristics, we conclude that cytoarchitectonic areas OP1, OP 4, and OP 3 on the human Parietal Operculum constitute the human homologues of primate areas SII, PV, and VS, respectively.
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Identifying human parieto-insular vestibular cortex using fMRI and cytoarchitectonic mapping.
Human brain mapping, 2006Co-Authors: Simon B. Eickhoff, Peter H. Weiss, Katrin Amunts, Gereon R. Fink, Karl ZillesAbstract:The parieto-insular vestibular cortex (PIVC) plays a central role in the cortical vestibular network. Although this region was first defined and subsequently extensively studied in nonhuman primates, there is also ample evidence for a human analogue in the posterior Parietal Operculum. In this study, we functionally and anatomically characterize the putative human equivalent to macaque area PIVC by combining functional magnetic resonance imaging (fMRI) of the cortical response to galvanic vestibular stimulation (GVS) with probabilistic cytoarchitectonic maps of the human Parietal Operculum. Our fMRI data revealed a bilateral cortical response to GVS in posterior parieto-insular cortex. Based on the topographic similarity of these activations to primate area PIVC, we suggest that they constitute the functionally defined human equivalent to macaque area PIVC. The locations of these activations were then compared to the probabilistic cytoarchitectonic maps of the Parietal Operculum (Eickhoff et al. [2005a]: Cereb Cortex, in press; Eickhoff et al. [2005c]: Cereb Cortex, in press), whereby the functionally defined PIVC matched most closely the cytoarchitectonically defined area OP 2. This activation of OP 2 by vestibular stimulation and its cytoarchitectonic features, which are similar to other primary sensory areas, suggest that area OP 2 constitutes the human equivalent of macaque area PIVC.
André Aleman - One of the best experts on this subject based on the ideXlab platform.
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Time Course of the Involvement of the Right Anterior Superior Temporal Gyrus and the Right Fronto-Parietal Operculum in Emotional Prosody Perception
PLOS ONE, 2008Co-Authors: Marjolijn Hoekert, Leonie Bais, René S. Kahn, André AlemanAbstract: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 more apparent half-way through the sentence.
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what is said or how it is said makes a difference role of the right fronto Parietal Operculum in emotional prosody as revealed by repetitive tms
European Journal of Neuroscience, 2005Co-Authors: André Aleman, Sophie Van Rijn, Eric Van Diessen, Celine Berckmoes, Guy Vingerhoets, René S. KahnAbstract:Emotional signals in spoken language can be conveyed by semantic as well as prosodic cues. We investigated the role of the fronto-Parietal Operculum, a somatosensory area where the lips, tongue and jaw are represented, in the right hemisphere to detection of emotion in prosody vs. semantics. A total of 14 healthy volunteers participated in the present experiment, which involved transcranial magnetic stimulation (TMS) in combination with frameless stereotaxy. As predicted, compared with sham stimulation, TMS over the right fronto-Parietal Operculum differentially affected the reaction times for detection of emotional prosody vs. emotional semantics, showing that there is a dissociation at a neuroanatomical level. Detection of withdrawal emotions (fear and sadness) in prosody was delayed significantly by TMS. No effects of TMS were observed for approach emotions (happiness and anger). We propose that the right fronto-Parietal Operculum is not globally involved in emotion evaluation, but sensitive to specific forms of emotional discrimination and emotion types.