Age and handicapped group differences in infants' visual attention.

102 handicapped children who ranged in age from 3 to 36 months and who were classified as Down's syndrome, cerebral palsied, developmentally delayed, or multiply handicapped were given a visual attention task. Subjects were presented 6 repeated trials of nonsocial stimuli followed by a seventh novel trial (20-sec trials, 20-sec intertrial intervals). Habituation to the repeated stimulus was assessed by examining fixation trends across the 6 trials. Differences in habituation as a function of chronological age, mental age, and handicapped group membership were examined. Over the entire sample, linear trends were found, as looking time decreased over trials. An age effect was found as the 3-7-month-olds did not exhibit a decrease in fixation over the 6 trials, while the older infants did exhibit response decrement. Parallel mental age differences in response decrement were found. No differences in fixation patterns were found for the 4 handicapped groups. Cluster analyses revealed 3 distinct fixation patterns over the 6 redundant trials, which were characterized by (1) high initial fixation and response decrement, (2) low initial fixation and no response decrement, and (3) moderate initial fixation and monotonic decrease in fixation over trials. Individual differences in cluster membership were found as a function of chronological and mental age but not handicapped group membership.