Classical eyeblink conditioning and schizophrenia: a short review.

There is considerable evidence for the involvement of cerebellar structures and circuits in classical conditioning of eyeblink responses (EBC) and in the pathophyiology of schizophrenia, leading to the expectation that schizophrenia patients should exhibit impaired EBC. A review of the literature indicates that such a position is not supported. Of the nine published studies, three reported poorer EBS in patients compared to controls, three reported better EBC, and three reported no significant EBC differences between the groups. Overall, medicated schizophrenia patients showed poorer EBC, and non-medicated patients exhibited better or normal EBC, relative to healthy control groups. In the light of those results and the fact that no experiment explicitly compared medicated and non-medicated patients, one cannot assume that the EBC deficits in patient groups are attributable to anything other than an effect from medication.