Looking into autism

Abstract

When one thinks of autism, it is probably the communicative and social impairments that come to mind first – overt behaviors such as social avoidance, lack of eye contact, or speech impairments. Elizabeth Milne and her colleagues, however, have new evidence that might help us to understand the lower-level mechanisms behind autism [ 1. Milne E. et al. High motion-coherence thresholds in children with autism. J. Child Psychol. Psychiatry. 2002; 43: 255-263 Crossref PubMed Scopus (305) Google Scholar ]. Children with autism were compared with age-matched control children on a motion-coherence task. Thresholds for motion detection were measured by presenting an array of moving dots on a computer screen; in each array, some of the dots move coherently (that is, in a common direction) and others move randomly. Importantly, each individual dot has a lifetime of only four frames, so to detect coherent motion, the child must be able to extract some global information from the display. Tracking an individual dot provides insufficient evidence to detect the coherent motion direction. The task thus provides a measure of sensitivity to global information in the stimulus.