Cerebral Specialization for Speech Perception and Movement Organization in Adults with Down's Syndrome

Adults with Down's syndrome and a group of undifferentiated mentally handicapped persons were examined using a free recall dichotic listening procedure to determine a laterality index for the perception of speech sounds. Subjects also performed both the visual and verbal portions of a standard apraxia battery. As in previous research, subjects with Down's syndrome tended to display a left ear advantage on the dichotic listening test. As well, …