SEMANTIC MEMORY IS BOTH IMPAIRED AND ANOMALOUS IN SCHIZOPHRENIA

The integrity of semantic memory in schizophrenia was examined in a re action time task requiring subjects to verify words as members or non- members of a conceptual category, where the words differed in their de gree of semantic relationship to the category. Compared to matched nor mal controls, 28 schizophrenic patients were impaired on the task, sho wing slower responses in all conditions. In addition, their performanc e was anomalous in that they took longest to respond to items that wer e outside the category but semantically related to it, in contrast to the controls who took the longest to respond to ambiguous words at the borderline of the category. The pattern of 'yes' and 'no' responses o f the patients was anomalous in a similar way. In both speed and accur acy of responding, the findings indicate that there is an outward shif t of semantic category boundaries in schizophrenia.