Simultaneous and delayed matching to sample in gesture users and speakers with mental retardation.

Sixty-eight participants with severe mental retardation participated in a study of representational matching to sample. Participants were asked to match objects to identical objects, line drawings, miniature objects (icons), pantomimes, and spoken names. Participants who were successful in these matching tasks also experienced delayed matching tasks. Participants differed in their expressive communication and comparisons were made between symbolic (speaking) individuals, distal gesture users, and contact gesture users. Contact gesture users were significantly worse on identical matching to sample tasks than other participants. Mean scores on matching objects to line drawings were significantly better than mean scores on other matching tasks. In delayed matching, however, scores for matching objects to spoken names were significantly better than other tasks. The implications of these results for learning to use an augmentative communication device are discussed.