Practice and serial reaction time of adolescents with autism.

This study examined effects of practice on timing of serial reactions by 7 adolescents diagnosed with autism by using a task requiring they track a series of timed lights. The adolescents showed significantly slower and more variable mean simple reaction time than 10 normal control subjects of the same age. On a task of tracking a serial light stimulation for 4 days, on the other hand, significant effects of practice on timing of serial reactions were observed for mean serial reaction times of them. In addition, from individual variations in reaction times and anticipatory reaction times, four of seven subjects with autism showed significant effects of practice. Analysis suggested that these autistic adolescents may be chunking together the whole series of responses and are unable to coordinate the timing of individual responses with individual stimuli. Our data indicate that at least some adolescents with autism are able to form and utilise a motor program with practice.