title: Visuomotor control within a distributed parieto-frontal network.
abstract: The aim of this functional magnetic resonance imaging study was to investigate differences in visuomotor control with increasing task complexity. Twelve right-handed volunteers were asked to perform their signature under different degrees of visual control: internally generated movement with closed eyes, signing with open eyes, tracking the line of the projected signature forwards, and tracking the line of the projected signature backwards. There was a gradual onset and disappearance of activation within a distributed network. Parietal, lateral and medial frontal brain areas were activated during all conditions, confirming the involvement of a parieto-frontal system. The weight of activation shifted with increasing task complexity. Internally generated movements activated predominantly the inferior parietal lobule and the ventral premotor cortex, as well as the rostral cingulate area, pre-supplementary motor area (pre-SMA) and SMA proper. Opening the eyes reduced SMA and cingulate activation and activated increasingly the occipito-parietal areas with higher task complexity. Visually guided movements produced an activation predominantly in the superior parietal lobule and dorsal premotor cortex. This study bridges human activation studies with the results of neurophysiological studies with monkeys. It confirms a gradual transition of visuomotor control with increasing task complexity within a distributed parieto-frontal network.
authors.affiliation: Department of Neurology, University of Hamburg-Eppendorf, Germany.
authors.forename: Farsin
authors.initials: F
authors.lastname: Hamzei
authors.forename: Christian
authors.initials: C
authors.lastname: Dettmers
authors.forename: Michel
authors.initials: M
authors.lastname: Rijntjes
authors.forename: Volkmar
authors.initials: V
authors.lastname: Glauche
authors.forename: Stefan
authors.initials: S
authors.lastname: Kiebel
authors.forename: Bettina
authors.initials: B
authors.lastname: Weber
authors.forename: Cornelius
authors.initials: C
authors.lastname: Weiller
mesh_terms: D000328:Adult; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*