Objectives: Memory deficits in patients with schizophrenia have been well established, but it is still unclear how memory performance changes during verbal learning tasks. This study was designed to assess the pattem of verbal learning and memory performance to test the inefficiency of encoding processes in learning of schizophrenia.
Method: Subjects consisted of 26 patients with schizophrenia who were unmedicated for atleast seven days and 22 normal controls who were matched for age,sex,and education. Verbal memory and learning were evaluated with computerized tasks composed of three consecutive immediate recall trials, a yes/no recognition test, and a delayed recall trial of a word list.
Results: Thepatients with schizophrenia showed significant learning deficits characterized by impaired immediate recall performance and poor learning of a word list. However, both verbal recognition performance and forgetting were comparable in both groups. Word clustering correlated significantly with recall performance. Clustering of patients decreased significantly over immediate and delay recall tasks and showed poor increase during consecutive recall tasks.
Conclusion: Thest findings indicate that verbal learning and mnemonic strategy are impaired but learned information appears to be preserved in patients with schizophrenia. The results are consistent with the notion that a learning deficit is closely related with impaired encoding precesses in schizophrenia.