Exploring the variation in the nature of the imitation impairment in low-functioning, nonverbal children with autism

Rogers and Pennington (1991) proposed that a deficient imitation ability results in a cascade of developmental disorders that are characteristic symptoms of autism. The causes underlying the imitation deficit remain open to question, and the nature of the deficit varies within children with autism. In the present study, two imitation batteries were created to assess imitation abilities in low-functioning, nonverbal children with autism. Performance was analysed at a group and individual level on different imitation categories, including gross-motor, fine-motor, oral-facial and vocal imitation, to investigate the effect of variation on the nature of the imitation impairment. Meaningless and meaningful gestures in terms of sign language were also compared to clarify confusions regarding this area of research, and vocal imitation was speculated to be related with expressive language. The results were surprising: participants performed highest on vocal imitation and lowest on motor imitations overall. It is tentatively speculated that impaired perception and production of movements may account for this finding. On the other hand, individual analysis suggested overall performance may be influenced by the presence of echolalia in the sample. Participants performed meaningless gestures better than meaningful gestures. This result is discussed in terms of the overall results, impaired motoric processes and symbolic theory. Surprisingly, gross-motor imitation was significantly negatively correlated with expressive language, and no significant association was found with vocal imitation. Again, these results could be influenced by echolalia. Future research is needed to understand the effect of echolalia on body imitation in autism. Limitations of the current study and general literature are discussed. Detailed individual imitation profiling is concluded to be important at the level of diagnosis and in deciding effective interventions to improve social and communicative behaviours in autism