[Neurological background of Asperger's disorder and other pervasive developmental disorders]

The core features of pervasive developmental disorder (PDD) are impairment in social interaction and restricted ranges of interest and activities with obsessive/compulsive traits. Clinical characteristics of PDD range across a variety of psychophysiological areas, from vigilance and autonomic arousal through attention to higher cognitive functions such as memory and language. The author reviewed hypotheses on the neurological background of PDD, which includes brainstem, cerebellum, prefrontal cortex, mirror neuron system, and amygdala and related circuit. Among them, the amygdala hypothesis appears to be most successful in explaining the core feature of PDD, i.e. social impairment. It is expected that advance in cognitive neuroscience on social behavior will clarify the link between neurological and clinical findings of Asperger's disorder.