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Description
In visuomotor control, the right hemisphere has been associated with visuospatial, and the left with visuotemporal processing. In right-handers, asymmetric bimanual tasks result in a preferred use of the left hand for spatial processing and of the right hand for temporal processing.
We investigated interhemispheric interactions in 24 right-handers during asymmetric bimanual isometric movements, using magnetoencephalography to identify the way the cerebral hemispheres interact with each other once when hemispheric specializations were respected and once when the cerebral hemispheres were forced to act against their processing preferences. The dual task scenario involved visuomotor tracking with one hand that was paralleled by a precisely timed ballistic grip without spatial control demands. Task to hand assignments changed between conditions. We investigated time-resolved partial directed connectivity between EMG-coherent sources.
Our results suggest the dual task problem is solved by cooperative interhemispheric interactions with, both, a left-right and a rostro-caudal gradient for temporo-spatial processing.