THE EFFECTS OF BIFRONTAL STROKE DURING CHILDHOOD ON VISUAL-ATTENTION - EVIDENCE FROM CHILDREN WITH SICKLE-CELL-ANEMIA

Recent studies indicate that the neural systems underlying the develop ment of visual attention may differ from the systems subserving attent ion in adulthood. Our study examined the effects of early brain injury on attentional operations. A covert orienting task (Posner, Cohen, & Rafal, 1982) was administered to 29 children with sickle cell anemia ( SCA), 17 of whom had experienced stroke (6 bifrontal and 11 diffuse), and 20 siblings without SCA. Children with bifrontal injury showed lat eralized impairment in early-stage attentional processing, consisting of faster reaction times to targets in the left visual field that were preceded by invalid cues. These results were similar to findings in a previous study of children with bifrontal perinatal injury (Craft, Wh ite, & Park, 1994). In contrast, children with diffuse lesions showed exaggerated increases in reaction time for invalidly cued targets in b oth visual fields. The performance of SCA children without strokes was similar to that of sibling control subjects. The results indicate tha t anterior brain regions play an important role in the development of attentional operations throughout childhood.