Selective retrieval and free emission of category exemplars in schizophrenia

In a free emission task, normals, chronic schizophrenics with only positive and those with only negative symptoms generated as many exemplars from natural language categories as they could in three minutes. While the overall output level of both schizophrenic groups was lower than that of the normals, neither showed intrusions of unrelated words, and the temporal distribution of the output was marked by a clustering pattern inconsistent with a selective attention deficit hypothesis. The schizophrenics with negative symptoms tended to produce consistently smaller clusters than the normals and the schizophrenics with positive symptoms, implicating a specific retrieval constriction. The relationship of this to the major negative symptom poverty of speech is discussed.