Directed forgetting in schizophrenia: prefrontal memory and inhibition deficits.

Schizophrenia is associated with cognitive deficits in the domains of working memory, strategic memory and other executive functions. In the current study we used a computerised and item-cued variant of the directed forgetting (DF) task to assess inhibitory processes in verbal memory. Twenty-five patients with schizophrenia and a group of matched controls were tested. Recognition memory was better for to-be-remembered (TBR) than for to-be-forgotten (TBF) words in both patients and controls. As compared to healthy controls the patients with schizophrenia showed overall memory deficits and difficulties to inhibit memories as indicated by a significant group by cue interaction and a smaller DF effect. The DF effect was associated with disease duration but not with symptom severity. Memory-related inhibition problems are difficult to assess in patients with schizophrenia and might be related to fronto-temporal disconnection.