The dissociation of perception and cognition in children with early brain damage

Reduced non-verbal compared to verbal intelligence is used in many outcome studies of perinatal complications as an indication of visual perceptual impairment. To investigate whether this is justified, we re-examined data sets from two previous studies, both of which used the visual perceptual battery L94. The first study comprised 47 children at risk for cerebral visual impairment due to prematurity or birth asphyxia, who had been administered the McCarthy Scales of Childrenʹs abilities. The second study evaluated visual perceptual abilities in 82 children with a physical disability. These childrenʹs intellectual ability had been assessed with the Wechsler Intelligence Scale for Children-Revised and/or Wechsler Pre-school and Primary Scale of Intelligence-Revised. No significant association was found between visual perceptual impairment and (1) reduced non-verbal to verbal intelligence; (2) increased non-verbal subtest scatter; or (3) non-verbal subtest profile deviation, for any of the intelligence scales. This result suggests that non-verbal intelligence subtests assess a complex of cognitive skills that are distinct from visual perceptual abilities, and that this assessment is not hampered by deficits in perceptual abilities as manifested in these children.