Distinct causal influences of parietal versus frontal areas on human visual cortex: evidence from concurrent TMS-fMRI

  • It has often been proposed that regions of the human parietal and/or frontal lobe may modulate activity in visual cortex, for example, during selective attention or saccade preparation. However, direct evidence for such causal claims is largely missing in human studies, and it remains unclear to what degree the putative roles of parietal and frontal regions in modulating visual cortex may differ. Here we used transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) concurrently, to show that stimulating right human intraparietal sulcus (IPS, at a site previously implicated in attention) elicits a pattern of activity changes in visual cortex that strongly depends on current visual context. Increased intensity of IPS TMS affected the blood oxygen level–dependent (BOLD) signal in V5/MT+ only when moving stimuli were present to drive this visual region, whereas TMS-elicited BOLD signal changes were observed in areas V1–V4 only during the absence of visual input. These influences of IPS TMS upon remote visual cortex differed significantly from corresponding effects of frontal (eye field) TMS, in terms of how they related to current visual input and their spatial topography for retinotopic areas V1–V4. Our results show directly that parietal and frontal regions can indeed have distinct patterns of causal influence upon functional activity in human visual cortex. Key words: attention, frontal cortex, functional magnetic resonance imaging, parietal cortex, top--down, transcranial magnetic stimulation

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Author:Christian C. Ruff, Sven Bestmann, Felix Blankenburg, Otto Bjoertomt, Oliver Josephs, Nikolaus WeiskopfORCiDGND, Ralf DeichmannORCiD, Jon Driver
Parent Title (German):Cerebral Cortex
Document Type:Article
Date of Publication (online):2010/11/12
Year of first Publication:2007
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2010/11/12
Tag:attention; frontal cortex; functional magnetic resonance imaging; parietal cortex; top-down; transcranial magnetic stimulation
First Page:817
Last Page:827
© The Author(s) 2007. Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Source:Cerebral Cortex, (2008) 18 (4): 817-827 ; doi: 10.1093/cercor/bhm128
Institutes:Medizin / Medizin
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Licence (German):License LogoCreative Commons - Namensnennung-Nicht kommerziell 2.0