It has been proposed that mentalising involves retrodicting as well as predicting behaviour, by inferring previous mental states of a target. This study investigated whether retrodiction is impaired in individuals with autism spectrum disorders (ASD). Participants watched videos of real people reacting to the researcher behaving in one of four possible ways. Their task was to decide which of these four "scenarios" each person responded to. Participants' eye movements were recorded. Participants with ASD were poorer than comparison participants at identifying the scenario to which people in the videos were responding. There were no group differences in time spent looking at the eyes or mouth. The findings imply those with ASD are impaired in using mentalising skills for retrodiction.
Matched MeSH terms: Child Development Disorders, Pervasive/psychology*
Asperger's Syndrome is a distinct variant of autism, with a prevalence rate of 10 to 26 per 10,000 of normal intelligence, and 0.4 per 10,000 in those with mild mental retardation. The syndrome now has its own clinical entity and diagnostic criteria. It is being officially listed in the ICD-10 under pervasive developmental disorder. Two such cases are described in this article. Case One lacked the ability to relate to others, was excessively preoccupied with the late actor P. Ramlee and demonstrated a peculiar behaviour of holding on to toothbrushes in his early childhood. Cognitively, he was unable to synthesise words into meaningful sentences. Similarly, Case Two was unable to relate well to others and was preoccupied with the planets and its constellations. Though he appeared intelligent with an IQ score of 101, he was unable to follow instructions at school. Both children had motor clumsiness and fulfilled the criteria for the diagnosis of Asperger's Syndrome.
Matched MeSH terms: Child Development Disorders, Pervasive/psychology