Hemispheric Speech Lateralization in Children with Auditory-Linguistic Deficits

Twenty-four children with learning problems not attributable to general intellectual, psychiatric, medical, or environmental factors, and clinically assessed as having deficits in auditory-linguistic skills, plus 24 normal children were tested with a verbal dichotic listening task. It was hypothesized that the learning-impaired children have atypical hemispheric speech lateralization which would be reflected in their performance on the dichotic listening test. The clinic children performed differently than the normal children in that they tended to report more left than right ear digits whereas the normal children tended to report more right than left ear digits. Further analyses suggested that there may be two types of children who manifest difficulty in auditory-linguistic skills, one group with speech represented in the left hemisphere, the other with speech represented in the right hemisphere. It was further suggested that left hemisphere dysfunction may be present in all the clinic children and may be the impetus for the cases of right-hemispheric speech lateralization. The data do not indicate a lack of hemispheric lateralization of speech processes in the type of learning-impaired child of the present study.