The Experts below are selected from a list of 14367 Experts worldwide ranked by ideXlab platform

Jinping Xu - One of the best experts on this subject based on the ideXlab platform.

  • delineating functional segregations of the human Middle Temporal Gyrus with resting state functional connectivity and coactivation patterns
    Human Brain Mapping, 2019
    Co-Authors: Jinping Xu, Jiaojian Wang, Tian Li, Ziyun Xu, Xianjun Fu, Qingmao Hu
    Abstract:

    : Although the Middle Temporal Gyrus (MTG) has been parcellated into subregions with distinguished anatomical connectivity patterns, whether the structural topography of MTG can inform functional segregations of this area remains largely unknown. Accumulating evidence suggests that the brain's underlying organization and function can be directly and effectively delineated with resting-state functional connectivity (RSFC) by identifying putative functional boundaries between cortical areas. Here, RSFC profiles were used to explore functional segregations of the MTG and defined four subregions from anterior to posterior in two independent datasets, which showed a similar pattern with MTG parcellation scheme obtained using anatomical connectivity. The functional segregations of MTG were further supported by whole brain RSFC, coactivation, and specific RFSC, and coactivation mapping. Furthermore, the fingerprint with predefined 10 networks and functional characterizations of each subregion using meta-analysis also identified functional distinction between subregions. The specific connectivity analysis and functional characterization indicated that the bilateral most anterior subregions mainly participated in social cognition and semantic processing; the ventral Middle subregions were involved in social cognition in left hemisphere and auditory processing in right hemisphere; the bilateral ventro-posterior subregions participated in action observation, whereas the left subregion was also involved in semantic processing; both of the dorsal subregions in superior Temporal sulcus were involved in language, social cognition, and auditory processing. Taken together, our findings demonstrated MTG sharing similar structural and functional topographies and provide more detailed information about the functional organization of the MTG, which may facilitate future clinical and cognitive research on this area.

  • tractography based parcellation of the human Middle Temporal Gyrus
    Scientific Reports, 2016
    Co-Authors: Jiaojian Wang, Jinping Xu, Qingmao Hu, Hai Li, Wen Zhang, Tianzi Jiang
    Abstract:

    The Middle Temporal Gyrus (MTG) participates in a variety of functions, suggesting the existence of distinct functional subregions. In order to further delineate the functions of this brain area, we parcellated the MTG based on its distinct anatomical connectivity profiles and identified four distinct subregions, including the anterior (aMTG), Middle (mMTG), posterior (pMTG), and sulcus (sMTG). Both the anatomical connectivity patterns and the resting-state functional connectivity patterns revealed distinct connectivity profiles for each subregion. The aMTG was primarily involved in the default mode network, sound recognition, and semantic retrieval. The mMTG was predominantly involved in the semantic memory and semantic control networks. The pMTG seems to be a part of the traditional sensory language area. The sMTG appears to be associated with decoding gaze direction and intelligible speech. Interestingly, the functional connectivity with Brodmann’s Area (BA) 40, BA 44, and BA 45 gradually increased from the anterior to the posterior MTG, a finding which indicated functional topographical organization as well as implying that language processing is functionally segregated in the MTG. These proposed subdivisions of the MTG and its functions contribute to understanding the complex functions of the MTG at the subregional level.

Jiaojian Wang - One of the best experts on this subject based on the ideXlab platform.

  • specific functional connectivity patterns of Middle Temporal Gyrus subregions in children and adults with autism spectrum disorder
    Autism Research, 2020
    Co-Authors: Chao Wang, Fangfang Chen, Kai Chen, Jingjing Gao, Jiaojian Wang
    Abstract:

    As one of the key regions in the "social brain" network, the Middle Temporal Gyrus (MTG) has been widely reported to be associated with autism spectrum disorder (ASD), but there have been contradictory results in terms of whether it shows hyperconnectivity or hypoconnectivity. Delineating roles of MTG at the subregional level may eliminate the observed inconsistencies and provide a new avenue to reveal the neurophysiologic mechanism of ASD. Thus, we first performed connectivity-based parcellation using the BrainMap database to identify fine-grained functional topography of the MTG. Then, the MTG subregions were used to investigate differences in the functional connectivity in children and adults with ASD using two data sets from Autism Brain Imaging Data Exchange database. Four distinct subregions in the human left and right MTG were identified, including the anterior MTG (aMTG), Middle-anterior MTG (maMTG), Middle-posterior MTG, and posterior MTG (pMTG). The bilateral pMTG was more vulnerable in both children and adults with ASD than in the typically developing (TD) group, mainly showing hypoconnectivity with different brain regions. In addition, the bilateral aMTG and right maMTG also showed altered functional connectivity in adults with ASD compared to the TD group. Moreover, all these altered MTG subregions were mainly associated with social cognition and language, as revealed by functional characterization. Further correlation analyses also showed trends of association between altered connectivity of the left aMTG and the Autism Diagnostic Observation Schedule scores in adults with ASD. Together, these results suggest a potential objective way to explore sub-regional differences associated with such disorders. Autism Res 2020, 13: 410-422. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Four distinct subregions in the human left and right Middle Temporal Gyrus (MTG) were identified, including the anterior MTG (aMTG), Middle-anterior MTG (maMTG), Middle-posterior MTG, and posterior MTG (pMTG). The bilateral pMTG was more vulnerable in both children and adults with autism spectrum disorder (ASD) than in the typically developing (TD) group, mainly showing hypoconnectivity with different brain regions. In addition, the bilateral aMTG and right maMTG also showed altered functional connectivity in adults with ASD compared to the TD group. Moreover, all these altered MTG subregions were mainly associated with social cognition and language, as revealed by functional characterization. Further correlation analyses also showed trends of association between altered connectivity of the left aMTG and the Autism Diagnostic Observation Schedule scores in adults with ASD.

  • delineating functional segregations of the human Middle Temporal Gyrus with resting state functional connectivity and coactivation patterns
    Human Brain Mapping, 2019
    Co-Authors: Jinping Xu, Jiaojian Wang, Tian Li, Ziyun Xu, Xianjun Fu, Qingmao Hu
    Abstract:

    : Although the Middle Temporal Gyrus (MTG) has been parcellated into subregions with distinguished anatomical connectivity patterns, whether the structural topography of MTG can inform functional segregations of this area remains largely unknown. Accumulating evidence suggests that the brain's underlying organization and function can be directly and effectively delineated with resting-state functional connectivity (RSFC) by identifying putative functional boundaries between cortical areas. Here, RSFC profiles were used to explore functional segregations of the MTG and defined four subregions from anterior to posterior in two independent datasets, which showed a similar pattern with MTG parcellation scheme obtained using anatomical connectivity. The functional segregations of MTG were further supported by whole brain RSFC, coactivation, and specific RFSC, and coactivation mapping. Furthermore, the fingerprint with predefined 10 networks and functional characterizations of each subregion using meta-analysis also identified functional distinction between subregions. The specific connectivity analysis and functional characterization indicated that the bilateral most anterior subregions mainly participated in social cognition and semantic processing; the ventral Middle subregions were involved in social cognition in left hemisphere and auditory processing in right hemisphere; the bilateral ventro-posterior subregions participated in action observation, whereas the left subregion was also involved in semantic processing; both of the dorsal subregions in superior Temporal sulcus were involved in language, social cognition, and auditory processing. Taken together, our findings demonstrated MTG sharing similar structural and functional topographies and provide more detailed information about the functional organization of the MTG, which may facilitate future clinical and cognitive research on this area.

  • tractography based parcellation of the human Middle Temporal Gyrus
    Scientific Reports, 2016
    Co-Authors: Jiaojian Wang, Jinping Xu, Qingmao Hu, Hai Li, Wen Zhang, Tianzi Jiang
    Abstract:

    The Middle Temporal Gyrus (MTG) participates in a variety of functions, suggesting the existence of distinct functional subregions. In order to further delineate the functions of this brain area, we parcellated the MTG based on its distinct anatomical connectivity profiles and identified four distinct subregions, including the anterior (aMTG), Middle (mMTG), posterior (pMTG), and sulcus (sMTG). Both the anatomical connectivity patterns and the resting-state functional connectivity patterns revealed distinct connectivity profiles for each subregion. The aMTG was primarily involved in the default mode network, sound recognition, and semantic retrieval. The mMTG was predominantly involved in the semantic memory and semantic control networks. The pMTG seems to be a part of the traditional sensory language area. The sMTG appears to be associated with decoding gaze direction and intelligible speech. Interestingly, the functional connectivity with Brodmann’s Area (BA) 40, BA 44, and BA 45 gradually increased from the anterior to the posterior MTG, a finding which indicated functional topographical organization as well as implying that language processing is functionally segregated in the MTG. These proposed subdivisions of the MTG and its functions contribute to understanding the complex functions of the MTG at the subregional level.

Elizabeth Jefferies - One of the best experts on this subject based on the ideXlab platform.

  • context dependent lexical ambiguity resolution meg evidence for the time course of activity in left inferior frontal Gyrus and posterior Middle Temporal Gyrus
    Brain and Language, 2018
    Co-Authors: Giovanna Mollo, Elizabeth Jefferies, Piers L. Cornelissen, Silvia P Gennari
    Abstract:

    An MEG study investigated the role of context in semantic interpretation by examining the comprehension of ambiguous words in contexts leading to different interpretations. We compared high-ambiguity words in minimally different contexts (to bowl, the bowl) to low-ambiguity counterparts (the tray, to flog). Whole brain beamforming revealed the engagement of left inferior frontal Gyrus (LIFG) and posterior Middle Temporal Gyrus (LPMTG). Points of interest analyses showed that both these sites showed a stronger response to verb-contexts by 200 ms post-stimulus and displayed overlapping ambiguity effects that were sustained from 300 ms onwards. The effect of context was stronger for high-ambiguity words than for low-ambiguity words at several different time points, including within the first 100 ms post-stimulus. Unlike LIFG, LPMTG also showed stronger responses to verb than noun contexts in low-ambiguity trials. We argue that different functional roles previously attributed to LIFG and LPMTG are in fact played out at different periods during processing.

  • tms interferes with lexical semantic retrieval in left inferior frontal Gyrus and posterior Middle Temporal Gyrus evidence from cyclical picture naming
    Neuropsychologia, 2014
    Co-Authors: Katya Kriegerredwood, Elizabeth Jefferies
    Abstract:

    We used TMS to investigate the contribution of left inferior frontal Gyrus (LIFG) and posterior Middle Temporal Gyrus (pMTG) to lexical/semantic selection and retrieval processes using a cyclical naming paradigm. Participants named pictures that were presented repeatedly across six cycles, either in semantically related or unrelated sets. Previous research has suggested that selection demands are higher for related sets, especially after repetition, since participants experience competition from the activation of semantic neighbours. In contrast, retrieval demands are greater for unrelated sets in the absence of semantic priming, particularly on the first cycle when the target names have not been previously activated. Therefore, this paradigm can reveal independent effects of (i) retrieval demands (i.e., the ease of accessing picture names from visual input) and (ii) selection/competition. We found that rTMS to LIFG and pMTG produced similar behavioural effects: stimulation of both sites disrupted picture naming performance on early cycles (when participants were less practised at producing the picture names) and for semantically-related sets (when there was the potential for increased competition and yet also facilitation from semantic neighbours). There were no effects of TMS when either retrieval or selection requirements were maximal on their own. The data therefore support the view that both LIFG and pMTG contribute to picture name retrieval, with both sites playing a critical role in mediating the semantic facilitation of naming when retrieval demands are high.

  • Both the Middle Temporal Gyrus and the ventral anterior Temporal area are crucial for multimodal semantic processing: Distortion-corrected fMRI evidence for a double gradient of information convergence in the Temporal lobes
    Journal of Cognitive Neuroscience, 2012
    Co-Authors: Maya Visser, Elizabeth Jefferies, Karl V. Embleton, Matthew A. Lambon Ralph
    Abstract:

    Most contemporary theories of semantic memory assume that concepts are formed from the distillation of information arising in distinct sensory and verbal modalities. The neural basis of this distillation or convergence of information was the focus of this study. Specifically, we explored two commonly posed hypotheses: (a) that the human Middle Temporal Gyrus (MTG) provides a crucial semantic interface given the fact that it interposes auditory and visual processing streams and (b) that the anterior Temporal region-especially its ventral surface (vATL)-provides a critical region for the multimodal integration of information. By utilizing distortion-corrected fMRI and an established semantic association assessment (commonly used in neuropsychological investigations), we compared the activation patterns observed for both the verbal and nonverbal versions of the same task. The results are consistent with the two hypotheses simultaneously: Both MTG and vATL are activated in common for word and picture semantic processing. Additional planned, ROI analyses show that this result follows from two principal axes of convergence in the Temporal lobe: both lateral (toward MTG) and longitudinal (toward the anterior Temporal lobe).

Qingmao Hu - One of the best experts on this subject based on the ideXlab platform.

  • delineating functional segregations of the human Middle Temporal Gyrus with resting state functional connectivity and coactivation patterns
    Human Brain Mapping, 2019
    Co-Authors: Jinping Xu, Jiaojian Wang, Tian Li, Ziyun Xu, Xianjun Fu, Qingmao Hu
    Abstract:

    : Although the Middle Temporal Gyrus (MTG) has been parcellated into subregions with distinguished anatomical connectivity patterns, whether the structural topography of MTG can inform functional segregations of this area remains largely unknown. Accumulating evidence suggests that the brain's underlying organization and function can be directly and effectively delineated with resting-state functional connectivity (RSFC) by identifying putative functional boundaries between cortical areas. Here, RSFC profiles were used to explore functional segregations of the MTG and defined four subregions from anterior to posterior in two independent datasets, which showed a similar pattern with MTG parcellation scheme obtained using anatomical connectivity. The functional segregations of MTG were further supported by whole brain RSFC, coactivation, and specific RFSC, and coactivation mapping. Furthermore, the fingerprint with predefined 10 networks and functional characterizations of each subregion using meta-analysis also identified functional distinction between subregions. The specific connectivity analysis and functional characterization indicated that the bilateral most anterior subregions mainly participated in social cognition and semantic processing; the ventral Middle subregions were involved in social cognition in left hemisphere and auditory processing in right hemisphere; the bilateral ventro-posterior subregions participated in action observation, whereas the left subregion was also involved in semantic processing; both of the dorsal subregions in superior Temporal sulcus were involved in language, social cognition, and auditory processing. Taken together, our findings demonstrated MTG sharing similar structural and functional topographies and provide more detailed information about the functional organization of the MTG, which may facilitate future clinical and cognitive research on this area.

  • tractography based parcellation of the human Middle Temporal Gyrus
    Scientific Reports, 2016
    Co-Authors: Jiaojian Wang, Jinping Xu, Qingmao Hu, Hai Li, Wen Zhang, Tianzi Jiang
    Abstract:

    The Middle Temporal Gyrus (MTG) participates in a variety of functions, suggesting the existence of distinct functional subregions. In order to further delineate the functions of this brain area, we parcellated the MTG based on its distinct anatomical connectivity profiles and identified four distinct subregions, including the anterior (aMTG), Middle (mMTG), posterior (pMTG), and sulcus (sMTG). Both the anatomical connectivity patterns and the resting-state functional connectivity patterns revealed distinct connectivity profiles for each subregion. The aMTG was primarily involved in the default mode network, sound recognition, and semantic retrieval. The mMTG was predominantly involved in the semantic memory and semantic control networks. The pMTG seems to be a part of the traditional sensory language area. The sMTG appears to be associated with decoding gaze direction and intelligible speech. Interestingly, the functional connectivity with Brodmann’s Area (BA) 40, BA 44, and BA 45 gradually increased from the anterior to the posterior MTG, a finding which indicated functional topographical organization as well as implying that language processing is functionally segregated in the MTG. These proposed subdivisions of the MTG and its functions contribute to understanding the complex functions of the MTG at the subregional level.

Emmanuel Stamatakis - One of the best experts on this subject based on the ideXlab platform.

  • left inferior frontal cortex and syntax function structure and behaviour in patients with left hemisphere damage
    Brain, 2011
    Co-Authors: Lorraine K Tyler, William D Marslenwilson, Billi Randall, Paul Wright, Barry J Devereux, Jie Zhuang, Marina Papoutsi, Emmanuel Stamatakis
    Abstract:

    For the past 150 years, neurobiological models of language have debated the role of key brain regions in language function. One consistently debated set of issues concern the role of the left inferior frontal Gyrus in syntactic processing. Here we combine measures of functional activity, grey matter integrity and performance in patients with left hemisphere damage and healthy participants to ask whether the left inferior frontal Gyrus is essential for syntactic processing. In a functional neuroimaging study, participants listened to spoken sentences that either contained a syntactically ambiguous or matched unambiguous phrase. Behavioural data on three tests of syntactic processing were subsequently collected. In controls, syntactic processing co-activated left hemisphere Brodmann areas 45/47 and posterior Middle Temporal Gyrus. Activity in a left parietal cluster was sensitive to working memory demands in both patients and controls. Exploiting the variability in lesion location and performance in the patients, voxel-based correlational analyses showed that tissue integrity and neural activity—primarily in left Brodmann area 45 and posterior Middle Temporal Gyrus—were correlated with preserved syntactic performance, but unlike the controls, patients were insensitive to syntactic preferences, reflecting their syntactic deficit. These results argue for the essential contribution of the left inferior frontal Gyrus in syntactic analysis and highlight the functional relationship between left Brodmann area 45 and the left posterior Middle Temporal Gyrus, suggesting that when this relationship breaks down, through damage to either region or to the connections between them, syntactic processing is impaired. On this view, the left inferior frontal Gyrus may not itself be specialized for syntactic processing, but plays an essential role in the neural network that carries out syntactic computations.

  • reorganization of syntactic processing following left hemisphere brain damage does right hemisphere activity preserve function
    Brain, 2010
    Co-Authors: Lorraine K Tyler, William D Marslenwilson, Billi Randall, Paul Wright, Emmanuel Stamatakis
    Abstract:

    The extent to which the human brain shows evidence of functional plasticity across the lifespan has been addressed in the context of pathological brain changes and, more recently, of the changes that take place during healthy ageing. Here we examine the potential for plasticity by asking whether a strongly left-lateralized system can successfully reorganize to the right-hemisphere following left-hemisphere brain damage. To do this, we focus on syntax, a key linguistic function considered to be strongly left-lateralized, combining measures of tissue integrity, neural activation and behavioural performance. In a functional neuroimaging study participants heard spoken sentences that differentially loaded on syntactic and semantic information. While healthy controls activated a left-hemisphere network of correlated activity including Brodmann areas 45/47 and posterior Middle Temporal Gyrus during syntactic processing, patients activated Brodmann areas 45/47 bilaterally and right Middle Temporal Gyrus. However, voxel-based morphometry analyses showed that only tissue integrity in left Brodmann areas 45/47 was correlated with activity and performance; poor tissue integrity in left Brodmann area 45 was associated with reduced functional activity and increased syntactic deficits. Activity in the right-hemisphere was not correlated with damage in the left-hemisphere or with performance. Reduced neural integrity in the left-hemisphere through brain damage or healthy ageing results in increased right-hemisphere activation in homologous regions to those left-hemisphere regions typically involved in the young. However, these regions do not support the same linguistic functions as those in the left-hemisphere and only indirectly contribute to preserved syntactic capacity. This establishes the unique role of the left hemisphere in syntax, a core component in human language.