VISUAL-ATTENTION IN CHILDREN WITH PERINATAL BRAIN INJURY - ASYMMETRICEFFECTS OF BILATERAL LESIONS

The neural systems underlying visual attention have been well-document ed in adults through studies examining the effects of brain lesions on specific attentional operations (Posner, Cohen, and Rafal, 1982). The questions of how this attentional system develops and how it is affec ted by disruption during development are only beginning to be addresse d. In the present study, a covert orienting task (Posner et al., 1982) was administered to 33 children with bilateral perinatal injury to an terior, posterior, or diffuse brain regions and 36 normal children to determine the effects of such injury on visual attention. Children wit h bilateral anterior lesions showed lateralized impairment indicating compromise of left hemisphere early attentional processes. In contrast , children with posterior lesions that typically disrupt attention in adults showed only general slowing, with no differences in right or le ft visual field performance or deficits in specific attentional operat ions. These results suggest that anterior brain regions play an import ant role in the development of visual attention, and that left hemisph ere attentional processes are particularly affected by disruption of a nterior function.