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

The neural systems underlying visual attention have been well-documented 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 affected by disruption during development are only beginning to be addressed. In the present study, a covert orienting task (Posner et al., 1982) was administered to 33 children with bilateral perinatal injury to anterior, posterior, or diffuse brain regions and 36 normal children to determine the effects of such injury on visual attention. Children with 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 left visual field performance or deficits in specific attentional operations. These results suggest that anterior brain regions play an important role in the development of visual attention, and that left hemisphere attentional processes are particularly affected by disruption of anterior function.