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The Human Intraparietal Sulcus Modulates Task-Evoked Functional Connectivity
Journal article   Peer reviewed

The Human Intraparietal Sulcus Modulates Task-Evoked Functional Connectivity

Kai Hwang, James M Shine, Dillan Cellier and Mark D’Esposito
Cerebral cortex (New York, N.Y. 1991), Vol.30(3), pp.875-887
03/2020
DOI: 10.1093/cercor/bhz133
PMCID: PMC7132937
PMID: 31355407
url
https://www.ncbi.nlm.nih.gov/pmc/articles/7132937View
Open Access

Abstract

Past studies have demonstrated that flexible interactions between brain regions support a wide range of goal-directed behaviors. However, the neural mechanisms that underlie adaptive communication between brain regions are not well understood. In this study, we combined theta-burst transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging to investigate the sources of top-down biasing signals that influence task-evoked functional connectivity. Subjects viewed sequences of images of faces and buildings and were required to detect repetitions (2-back vs. 1-back) of the attended stimuli category (faces or buildings). We found that functional connectivity between ventral temporal cortex and the primary visual cortex (VC) increased during processing of task-relevant stimuli, especially during higher memory loads. Furthermore, the strength of functional connectivity was greater for correct trials. Increases in task-evoked functional connectivity strength were correlated with increases in activity in multiple frontal, parietal, and subcortical (caudate and thalamus) regions. Finally, we found that TMS to superior intraparietal sulcus (IPS), but not to primary somatosensory cortex, decreased task-specific modulation in connectivity patterns between the primary VC and the parahippocampal place area. These findings demonstrate that the human IPS is a source of top-down biasing signals that modulate task-evoked functional connectivity among task-relevant cortical regions.
intraparietal sulcus cognitive control functional connectivity TMS working memory Original

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