Interactive memory systems and category learning in schizophrenia.

Schizophrenia is a devastating mental disorder with multiple facets, including the impairment of learning and memory. Recent evidence suggests that information is processed and represented by multiple interacting memory systems in the brain, including prefrontal cortex, basal ganglia, and medial temporal lobe. These structures are critical in the pathophysiology of schizophrenia. Whereas executive and declarative memory dysfunctions are well known in schizophrenia, habit learning deficits related to the basal ganglia are less clear, despite the fact that dopaminergic and other neurochemical processes in the basal ganglia may play a crucial role in the pathophysiology and pharmacology of schizophrenia. In this article, I propose that the investigation of different classification learning functions, including reward- and feedback-guided learning and acquired equivalence learning, may shed light on the neuropsychology, pathophysiology, pharmacology, and behavioral genetics of schizophrenia.