Visuo-motor pathways in humans revealed by event-related fMRI.
Details
State: Public
Version: Final published version
License: Not specified
It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.
Serval ID
serval:BIB_86B3F9C7D1D5
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Visuo-motor pathways in humans revealed by event-related fMRI.
Journal
Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation cérébrale
ISSN
0014-4819
Publication state
Published
Issued date
2006
Peer-reviewed
Oui
Volume
170
Number
4
Pages
472-487
Language
english
Abstract
Whether different brain networks are involved in generating unimanual responses to a simple visual stimulus presented in the ipsilateral versus contralateral hemifield remains a controversial issue. Visuo-motor routing was investigated with event-related functional magnetic resonance imaging (fMRI) using the Poffenberger reaction time task. A 2 hemifield x 2 response hand design generated the "crossed" and "uncrossed" conditions, describing the spatial relation between these factors. Both conditions, with responses executed by the left or right hand, showed a similar spatial pattern of activated areas, including striate and extrastriate areas bilaterally, SMA, and M1 contralateral to the responding hand. These results demonstrated that visual information is processed bilaterally in striate and extrastriate visual areas, even in the "uncrossed" condition. Additional analyses based on sorting data according to subjects' reaction times revealed differential crossed versus uncrossed activity only for the slowest trials, with response strength in infero-temporal cortices significantly correlating with crossed-uncrossed differences (CUD) in reaction times. Collectively, the data favor a parallel, distributed model of brain activation. The presence of interhemispheric interactions and its consequent bilateral activity is not determined by the crossed anatomic projections of the primary visual and motor pathways. Distinct visuo-motor networks need not be engaged to mediate behavioral responses for the crossed visual field/response hand condition. While anatomical connectivity heavily influences the spatial pattern of activated visuo-motor pathways, behavioral and functional parameters appear to also affect the strength and dynamics of responses within these pathways.
Keywords
Adult, Analysis of Variance, Brain Mapping, Efferent Pathways, Female, Functional Laterality, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Middle Aged, Motor Cortex, Neuropsychological Tests, Oxygen, Photic Stimulation, Psychomotor Performance, Reaction Time, Time Factors, Visual Cortex
Pubmed
Web of science
Open Access
Yes
Create date
07/03/2008 10:37
Last modification date
14/02/2022 8:55