title: Don't watch where you're going: The neural correlates of decoupling eye and arm movements.
abstract: "Standard" visually-guided reaching movements consist of a saccade and an arm movement to the same target location. In the current study, functional magnetic resonance imaging was used to contrast brain activity during standard visually-guided reaches with activity during a "non-standard" visuomotor mapping where the targets of the saccade and arm movement were spatially decoupled. Multi-voxel pattern analysis approaches showed discrimination of standard versus non-standard visuomotor mapping in the cuneus and medial premotor regions without accompanying task-related differences in MRI signal amplitude in these areas. Contrasts of signal amplitude did reveal greater activity associated with the non-standard task relative to the standard task in the right inferior parietal lobule and a portion of the left superior posterior cerebellum. The findings of this study shed light on brain regions involved in overcoming our default tendency to spatially couple eye and arm movements during visually-guided reaching. Further, the results suggest that the regions reported here may be important in neurological disorders such as optic ataxia, Alzheimer's disease, and mild cognitive impairment, which are associated with deficits in producing non-standard visuomotor mappings while leaving standard visuomotor mapping relatively intact.
authors.affiliation: School of Kinesiology and Health Science, Centre for Vision Research, York University, 4700 Keele St., Toronto, ON M3J 1P3, Canada. Electronic address: gorbetd@yorku.ca.
authors.forename: D J
authors.initials: DJ
authors.lastname: Gorbet
authors.affiliation: School of Kinesiology and Health Science, Centre for Vision Research, York University, 4700 Keele St., Toronto, ON M3J 1P3, Canada. Electronic address: lsergio@yorku.ca.
authors.forename: L E
authors.initials: LE
authors.lastname: Sergio
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D053483:Eye Movement Measurements; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009043:Motor Activity / Q000502:physiology*
keywords: Visually-guided reaching; Visuomotor mapping; fMRI