Neuropsychologic function of children with severe hearing impairment

A neuropsychologic and medical study was carried out on a selected sample of 34 hearing-impaired children aged seven to 10 years at the onset of the study. In 16 children the cause of the hearing loss was thought to be exogenous. Eight of these had evidence for organic brain dysfunction. Nine children were thought to have genetic etiologies, and in nine no cause could be determined (sporadic hearing loss). Medical examination revealed several unsuspected abnormalities, particularly visual ones. Motor and visual motor deficits were frequent among hearing-impaired children with brain damage. The Performance Scale of the Wechsler Intelligence Scale for Children, and Raven's Coloured Progressive Matrices, as well as the Paper Folding item of the Hiskey-Nebraska Test of Learning Aptitude appeared sensitive to the presence of brain damage. The mean score for the WISC Performance Scale fell within the average range for hearing children, supporting previous findings of cognitive competence of the deaf. In this sample, Hiskey-Nebraska scores tended to be lower than WISC scores. Reasons for this discrepancy were suggested and did not appear to be accounted for by brain damage. Deficits in items requiring visual memory, sequencing, and categorization were relatively prevalent but showed no etiologic predilection. They were thought to be related to the consequence of hearing loss rather than to brain damage. Difficulty with stereognosis highlighted the problem of deciding why a hearing-impaired child might fail a particular task. This difficulty suggested that failure might not indicate a deficit in the function the task was designed to measure, but rather, reliance on an inefficient strategy for success.