Impairment of consciously controlled use of memory in schizophrenia

Recent studies of memory in schizophrenia have shown that explicit but not implicit memory performance is impaired. The hypothesis that schizophrenia is associated with a failure of consciously but not unconsciously (automatic) controlled influence of memory on performance was tested using a procedure providing uncontaminated estimates of consciously controlled and automatic memory processes (i.e., the process-dissociation procedure in a stem completion task). Performance of 35 patients with schizophrenia was compared with that of 35 normal participants. Consciously controlled use but not automatic influences of memory was significantly lower in patients with schizophrenia than in controls. Consciously controlled use of memory was negatively and significantly correlated with positive symptoms of schizophrenia. Schizophrenia differentially affects 2 types of memory processes: It impairs consciously controlled use of memory but spares automatic influences. Positive symptoms could reflect the lack of control from higher level conscious processes.