A lateralized brain network for visuospatial attention

The authors report the existence of a bilateral parieto-frontal network in humans whose hemispheric lateralization predicts the degree of specialization of the right hemisphere for visuospatial attention. This specialization is associated with an unbalanced speed of visuospatial processing between the two hemispheres. Right hemisphere dominance for visuospatial attention is characteristic of most humans, but its anatomical basis remains unknown. We report the first evidence in humans for a larger parieto-frontal network in the right than left hemisphere, and a significant correlation between the degree of anatomical lateralization and asymmetry of performance on visuospatial tasks. Our results suggest that hemispheric specialization is associated with an unbalanced speed of visuospatial processing.