The Experts below are selected from a list of 8037 Experts worldwide ranked by ideXlab platform
Jiaojian Wang - One of the best experts on this subject based on the ideXlab platform.
-
Connectional asymmetry of the Inferior Parietal Lobule shapes hemispheric specialization in humans, chimpanzees, and rhesus macaques
'eLife Sciences Publications Ltd', 2021Co-Authors: Luqi Cheng, Jiaojian Wang, Yuanchao Zhang, Chet Sherwood, Gaolang Gong, Lingzhong Fan, Tianzi JiangAbstract:The Inferior Parietal Lobule (IPL) is one of the most expanded cortical regions in humans relative to other primates. It is also among the most structurally and functionally asymmetric regions in the human cerebral cortex. Whether the structural and connectional asymmetries of IPL subdivisions differ across primate species and how this relates to functional asymmetries remain unclear. We identified IPL subregions that exhibited positive allometric in both hemispheres, scaling across rhesus macaque monkeys, chimpanzees, and humans. The patterns of IPL subregions asymmetry were similar in chimpanzees and humans, but no IPL asymmetries were evident in macaques. Among the comparative sample of primates, humans showed the most widespread asymmetric connections in the frontal, Parietal, and temporal cortices, constituting leftward asymmetric networks that may provide an anatomical basis for language and tool use. Unique human asymmetric connectivity between the IPL and primary motor cortex might be related to handedness. These findings suggest that structural and connectional asymmetries may underlie hemispheric specialization of the human brain
-
regional homogeneity and functional connectivity patterns in major depressive disorder cognitive vulnerability to depression and healthy subjects
Journal of Affective Disorders, 2018Co-Authors: Xinru Yuan, Jiaojian Wang, Lu Zhang, Yini He, Jing XiaoAbstract:Abstract Background Cognitive vulnerability to depression (CVD) is a high risk for depressive disorder. Recent studies focus on individuals with CVD to determine the neural basis of major depressive disorder (MDD) neuropathology. However, whether CVD showed specific or similar brain functional activity and connectivity patterns, compared to MDD, remain largely unknown. Methods Here, using resting-state functional magnetic resonance imaging in subjects with CVD, healthy controls (HC) and MDD, regional homogeneity (ReHo) and resting-state functional connectivity (R-FC) analyses were conducted to assess local synchronization and changes in functional connectivity patterns. Results Significant ReHo differences were found in right posterior lobe of cerebellum (PLC), left lingual gyrus (LG) and precuneus. Compared to HC, CVD subjects showed increased ReHo in the PLC, which was similar to the difference found between MDD and HC. Compared to MDD patients, CVD subjects showed decreased ReHo in PLC, LG, and precuneus. R-FC analyses found increased functional connections between LG and left Inferior Parietal Lobule, posterior cingulate cortex, and dorsolateral prefrontal cortex in CVD compared to both HC and MDD. Moreover, Regional mean ReHo values were positively correlated with Center for Epidemiologic Studies Depression Scale scores. Conclusion These analyses revealed that PLC and functional connections between LG and left Inferior Parietal Lobule, posterior cingulate cortex, and dorsolateral prefrontal cortex may be a potential marker for CVD.
-
correspondent functional topography of the human left Inferior Parietal Lobule at rest and under task revealed using resting state fmri and coactivation based parcellation
Human Brain Mapping, 2017Co-Authors: Jiaojian Wang, Benjamin Becker, Simon B EickhoffAbstract:The human left Inferior Parietal Lobule (LIPL) plays a pivotal role in many cognitive functions and is an important node in the default mode network (DMN). Although many previous studies have proposed different parcellation schemes for the LIPL, the detailed functional organization of the LIPL and the exact correspondence between the DMN and LIPL subregions remain unclear. Mounting evidence indicates that spontaneous fluctuations in the brain are strongly associated with cognitive performance at the behavioral level. However, whether a consistent functional topographic organization of the LIPL during rest and under task can be revealed remains unknown. Here, they used resting-state functional connectivity (RSFC) and task-related coactivation patterns separately to parcellate the LIPL and identified seven subregions. Four subregions were located in the supramarginal gyrus (SMG) and three subregions were located in the angular gyrus (AG). The subregion-specific networks and functional characterization revealed that the four anterior subregions were found to be primarily involved in sensorimotor processing, movement imagination and inhibitory control, audition perception and speech processing, and social cognition, whereas the three posterior subregions were mainly involved in episodic memory, semantic processing, and spatial cognition. The results revealed a detailed functional organization of the LIPL and suggested that the LIPL is a functionally heterogeneous area. In addition, the present study demonstrated that the functional architecture of the LIPL during rest corresponds with that found in task processing.
-
tractography based parcellation of the human left Inferior Parietal Lobule
NeuroImage, 2012Co-Authors: Jiaojian Wang, Yuanchao Zhang, Yu Zhang, Di Jiang, Chunshui YuAbstract:The Inferior Parietal Lobule (IPL) is a functionally and anatomically heterogeneous region. Much of the information about the anatomical connectivity and parcellation of this region was obtained from histological studies on non-human primates. However, whether these findings from non-human primates can be applied to the human Inferior Parietal Lobule, especially the left Inferior Parietal Lobule, which shows evidence of considerable evolution from primates to humans, remains unclear. In this study, diffusion MRI was employed to investigate the anatomical connectivities of the human left Inferior Parietal Lobule. Using a new algorithm, spectral clustering with edge-weighted centroidal voronoi tessellations, to search for regional variations in the probabilistic connectivity profiles of all left Inferior Parietal Lobule voxels with all the rest of the brain identified six subregions with distinctive connectivity properties in the left Inferior Parietal Lobule. Consistent with cytoarchitectonic findings, four subregions were found in the left supramarginal gyrus and two subregions in the left angular gyrus. The specific connectivity patterns of each subregion of the left Inferior Parietal Lobule were supported by both the anatomical and functional connectivity properties for each subregion, as calculated by a meta-analysis-based target method and by voxel-based whole brain anatomical and functional connectivity analyses. The proposed parcellation scheme for the human left Inferior Parietal Lobule and the maximum probability map for each subregion may facilitate more detailed future studies of this brain area.
Michael Petrides - One of the best experts on this subject based on the ideXlab platform.
-
dissociating the white matter tracts connecting the temporo Parietal cortical region with frontal cortex using diffusion tractography
Scientific Reports, 2020Co-Authors: Elise B Barbeau, Michael Petrides, Maxime DescoteauxAbstract:Three major white matter pathways connect the posterior temporal region and the adjacent Inferior Parietal Lobule with the lateral frontal cortex: the arcuate fasciculus (AF), and the second and third branches of the superior longitudinal fasciculus (SLF II and SLF III). These pathways are found also in nonhuman primate brains where they play specific roles in auditory and spatial processing. The precise origin, course, and termination of these pathways has been examined in invasive tract tracing studies in macaque monkeys. Here we use this prior knowledge to improve dissections of these pathways in vivo in the human brain using diffusion Magnetic Resonance Imaging (MRI) tractography. In this study, the AF, originating from the posterior temporal cortex, has been successfully separated from the SLF II and SLF III tracts originating from the angular and supramarginal gyri of the Inferior Parietal Lobule, respectively. The latter two pathways, i.e. SLF II and SLF III, have also been clearly separated from each other. Furthermore, we report for the first time in the human brain the dorsal branch of the AF that targets the posterior dorsolateral frontal region. These improved dissection protocols provide a solid basis for exploring the respective functional roles of these major fasciculi.
-
distinct Parietal and temporal pathways to the homologues of broca s area in the monkey
PLOS Biology, 2009Co-Authors: Michael Petrides, D. N. PandyaAbstract:The homologues of the two distinct architectonic areas 44 and 45 that constitute the anterior language zone (Broca's region) in the human ventrolateral frontal lobe were recently established in the macaque monkey. Although we know that the Inferior Parietal Lobule and the lateral temporal cortical region project to the ventrolateral frontal cortex, we do not know which of the several cortical areas found in those regions project to the homologues of Broca's region in the macaque monkey and by means of which white matter pathways. We have used the autoradiographic method, which permits the establishment of the cortical area from which axons originate (i.e., the site of injection), the precise course of the axons in the white matter, and their termination within particular cortical areas, to examine the Parietal and temporal connections to area 44 and the two subdivisions of area 45 (i.e., areas 45A and 45B). The results demonstrated a ventral temporo-frontal stream of fibers that originate from various auditory, multisensory, and visual association cortical areas in the intermediate superolateral temporal region. These axons course via the extreme capsule and target most strongly area 45 with a more modest termination in area 44. By contrast, a dorsal stream of axons that originate from various cortical areas in the Inferior Parietal Lobule and the adjacent caudal superior temporal sulcus was found to target both areas 44 and 45. These axons course in the superior longitudinal fasciculus, with some axons originating from the ventral Inferior Parietal Lobule and the adjacent superior temporal sulcus arching and forming a simple arcuate fasciculus. The cortex of the most rostral part of the Inferior Parietal Lobule is preferentially linked with the ventral premotor cortex (ventral area 6) that controls the orofacial musculature. The cortex of the intermediate part of the Inferior Parietal Lobule is linked with both areas 44 and 45. These findings demonstrate the posterior Parietal and temporal connections of the ventrolateral frontal areas, which, in the left hemisphere of the human brain, were adapted for various aspects of language production. These precursor circuits that are found in the nonlinguistic, nonhuman, primate brain also exist in the human brain. The possible reasons why these areas were adapted for language use in the human brain are discussed. The results throw new light on the prelinguistic precursor circuitry of Broca's region and help understand functional interactions between Broca's ventrolateral frontal region and posterior Parietal and temporal association areas.
-
ventrolateral prefrontal cortex and tactile memory disambiguation in the human brain
Proceedings of the National Academy of Sciences of the United States of America, 2007Co-Authors: Penelope Kostopoulos, Marieclaire Albanese, Michael PetridesAbstract:Tactile sensory information is first channeled from the primary somatosensory cortex on the postcentral gyrus to the Parietal opercular region (i.e., the secondary somatosensory cortex) and the rostral Inferior Parietal Lobule and, from there, to the prefrontal cortex, with which bidirectional connections exist. Although we know that tactile memory signals can be found in the prefrontal cortex, the contribution of the different prefrontal areas to tactile memory remains unclear. The present functional MRI study shows that a specific part of the prefrontal cortex in the human brain, namely the midventrolateral prefrontal region (cytoarchitectonic areas 47/12 and 45), is involved in active controlled retrieval processing necessary for the disambiguation of vibrotactile information in short-term memory. Furthermore, we demonstrate that this particular part of the prefrontal cortex interacts functionally with the secondary somatosensory areas in the Parietal operculum and the rostral Inferior Parietal Lobule during controlled processing for the retrieval of specific tactile information.
Leonardo Fogassi - One of the best experts on this subject based on the ideXlab platform.
-
functional organization of Inferior Parietal Lobule convexity in the macaque monkey electrophysiological characterization of motor sensory and mirror responses and their correlation with cytoarchitectonic areas
European Journal of Neuroscience, 2008Co-Authors: Stefano Rozzi, Giacomo Rizzolatti, Pier Francesco Ferrari, Luca Bonini, Leonardo FogassiAbstract:The general view on the functional role of the monkey Inferior Parietal Lobule (IPL) convexity mainly derives from studies carried out more than two decades ago and does not account for the functional complexity suggested by more recent neuroanatomical findings. We investigated this issue by recording multi- and single units in the IPL convexity of two monkeys and characterizing their somatosensory, visual and motor responses, using a naturalistic (ethologically relevant) approach. These properties were then matched with IPL cytoarchitectonic parcellation. A further aim of this study was to describe the general properties and the localization of IPL mirror neurons, until now not investigated in detail. Results showed that each studied cytoarchitectonic subdivision of the IPL (PF, PFG, PG) is characterized by specific sensory and motor properties. A key feature of the recorded motor neurons is that of coding goal-directed motor acts. Motor responses are somatotopically organized in a rostro-caudal fashion, with mouth, hand and arm represented in PF, PFG and PG, respectively, with a certain degree of overlap between adjacent representations. In each subdivision the motor activity is associated with specific somatosensory and visual responses, suggesting that each area organizes motor acts in different space sectors. Mirror neurons have been found mainly in area PFG and their general features appear to be very similar to those of ventral premotor mirror neurons. The present data suggest that the IPL plays an important role in both action organization and action understanding and should be considered part of the motor system.
-
Motor functions of the Parietal lobe
Current Opinion in Neurobiology, 2005Co-Authors: Leonardo Fogassi, Giuseppe LuppinoAbstract:There is now general agreement that the posterior Parietal cortex is part of the motor system. New data have confirmed its fundamental role in visuomotor transformations. Most interestingly, recent data showed that the Inferior Parietal Lobule codes motor acts (such as grasping) in a specific way according to the action in which they are embedded. This particular motor organization appears to provide a neural mechanism for higher order cognitive motor functions, including understanding of intention. These functions, and peripersonal space representation, are represented in areas of the Inferior Parietal Lobule, where visual information from both the dorsal and the ventral stream is integrated with motor information.
D. N. Pandya - One of the best experts on this subject based on the ideXlab platform.
-
distinct Parietal and temporal pathways to the homologues of broca s area in the monkey
PLOS Biology, 2009Co-Authors: Michael Petrides, D. N. PandyaAbstract:The homologues of the two distinct architectonic areas 44 and 45 that constitute the anterior language zone (Broca's region) in the human ventrolateral frontal lobe were recently established in the macaque monkey. Although we know that the Inferior Parietal Lobule and the lateral temporal cortical region project to the ventrolateral frontal cortex, we do not know which of the several cortical areas found in those regions project to the homologues of Broca's region in the macaque monkey and by means of which white matter pathways. We have used the autoradiographic method, which permits the establishment of the cortical area from which axons originate (i.e., the site of injection), the precise course of the axons in the white matter, and their termination within particular cortical areas, to examine the Parietal and temporal connections to area 44 and the two subdivisions of area 45 (i.e., areas 45A and 45B). The results demonstrated a ventral temporo-frontal stream of fibers that originate from various auditory, multisensory, and visual association cortical areas in the intermediate superolateral temporal region. These axons course via the extreme capsule and target most strongly area 45 with a more modest termination in area 44. By contrast, a dorsal stream of axons that originate from various cortical areas in the Inferior Parietal Lobule and the adjacent caudal superior temporal sulcus was found to target both areas 44 and 45. These axons course in the superior longitudinal fasciculus, with some axons originating from the ventral Inferior Parietal Lobule and the adjacent superior temporal sulcus arching and forming a simple arcuate fasciculus. The cortex of the most rostral part of the Inferior Parietal Lobule is preferentially linked with the ventral premotor cortex (ventral area 6) that controls the orofacial musculature. The cortex of the intermediate part of the Inferior Parietal Lobule is linked with both areas 44 and 45. These findings demonstrate the posterior Parietal and temporal connections of the ventrolateral frontal areas, which, in the left hemisphere of the human brain, were adapted for various aspects of language production. These precursor circuits that are found in the nonlinguistic, nonhuman, primate brain also exist in the human brain. The possible reasons why these areas were adapted for language use in the human brain are discussed. The results throw new light on the prelinguistic precursor circuitry of Broca's region and help understand functional interactions between Broca's ventrolateral frontal region and posterior Parietal and temporal association areas.
-
The extreme capsule in humans and rethinking of the language circuitry
Brain Structure and Function, 2008Co-Authors: Nikos Makris, D. N. PandyaAbstract:Experimental and imaging studies in monkeys have outlined various long association fiber pathways within the fronto-temporo-Parietal region. In the present study, the trajectory of the extreme capsule (EmC) fibers has been delineated in five human subjects using DT-MRI tractography. The EmC seems to be a long association fiber pathway, which courses between the Inferior frontal region and the superior temporal gyrus extending into the Inferior Parietal Lobule. Comparison of EmC fibers with the adjacent association fiber pathway, the middle longitudinal fascicle (MdLF), in the same subjects reveals that EmC is located in a medial and rostral position relative to MdLF flanking in part the medial wall of the insula. The EmC can also be differentiated from other neighboring fiber pathways such as the external capsule, uncinate fascicle, arcuate fascicle, superior longitudinal fascicles II and III, and the Inferior longitudinal fascicle. Given the location of EmC within the language zone, specifically Broca’s area in the frontal lobe, and Wernicke’s area in the temporal lobe and Inferior Parietal Lobule, it is suggested that the extreme capsule could have a role in language function.
Giacomo Rizzolatti - One of the best experts on this subject based on the ideXlab platform.
-
an area specifically devoted to tool use in human left Inferior Parietal Lobule
Behavioral and Brain Sciences, 2012Co-Authors: Guy Orban, Giacomo RizzolattiAbstract:A comparative fMRI study by Peeters et al. (2009) provided evidence that a specific sector of left Inferior Parietal Lobule is devoted to tool use in humans, but not in monkeys. We propose that this area represents the neural substrate of the human capacity to understand tool use by using causal reasoning.
-
functional organization of Inferior Parietal Lobule convexity in the macaque monkey electrophysiological characterization of motor sensory and mirror responses and their correlation with cytoarchitectonic areas
European Journal of Neuroscience, 2008Co-Authors: Stefano Rozzi, Giacomo Rizzolatti, Pier Francesco Ferrari, Luca Bonini, Leonardo FogassiAbstract:The general view on the functional role of the monkey Inferior Parietal Lobule (IPL) convexity mainly derives from studies carried out more than two decades ago and does not account for the functional complexity suggested by more recent neuroanatomical findings. We investigated this issue by recording multi- and single units in the IPL convexity of two monkeys and characterizing their somatosensory, visual and motor responses, using a naturalistic (ethologically relevant) approach. These properties were then matched with IPL cytoarchitectonic parcellation. A further aim of this study was to describe the general properties and the localization of IPL mirror neurons, until now not investigated in detail. Results showed that each studied cytoarchitectonic subdivision of the IPL (PF, PFG, PG) is characterized by specific sensory and motor properties. A key feature of the recorded motor neurons is that of coding goal-directed motor acts. Motor responses are somatotopically organized in a rostro-caudal fashion, with mouth, hand and arm represented in PF, PFG and PG, respectively, with a certain degree of overlap between adjacent representations. In each subdivision the motor activity is associated with specific somatosensory and visual responses, suggesting that each area organizes motor acts in different space sectors. Mirror neurons have been found mainly in area PFG and their general features appear to be very similar to those of ventral premotor mirror neurons. The present data suggest that the IPL plays an important role in both action organization and action understanding and should be considered part of the motor system.