Abnormal classical eye-blink conditioning in autism.

Cerebellar and limbic system pathologies have been reported in persons with autism. Because these brain areas are involved centrally in the acquisition and performance in classical eye-blink conditioning, this study evaluated conditioning in 11 persons with autism. Compared to matched controls, persons with autism learned the task faster but performed short-latency, high-amplitude conditioned responses. In addition, differences in learning the extinction rates systematically varied with age thus suggesting a developmental conditioning abnormality in autism. The observed pattern of eye-blink conditioning may indicate that persons with autism have the ability to rapidly associate paired stimuli but, depending on processing of certain contextual information, have impairments in modulating the timing and topography of the learned responses. This abnormality may relate to deviant cerebellar-hippocampal interactions. The classical eye-blink conditioning paradigm may provide a useful model for understanding the biological and behavioral bases of autism.