The effect of revelation of words and faces on recognition accuracy and decision bias in schizophrenia

In a series of experiments, we explored recognition accuracy and whether the recognition decision bias, termed the revelation effect, was present or absent in participants with schizophrenia. The revelation effect occurs when items are tested in an initially distorted manner and "revealed" before recognition decisions. The "revealed" items tend to be recognized more frequently, whether targets or lures, than items tested in a normal manner. Memory research in schizophrenia has found conflicting performance on recognition tests. Some studies found normal recognition performance (e.g., Goldberg, Torrey, Gold, Ragland, Bigelow, and Weinberger, 1993) and others found impaired performance (e.g., Clare, McKenna, Mortimer, & Baddeley, 1993). In this study, recognition accuracy was explored within the framework of revelation effect studies. Revelation effect research has not been done with schizophrenic patients to date. An investigation of a decision bias in recognition would shed light both on the explanations of the revelation effect and the processes participants with schizophrenia engage in during recognition. Across experiments, the schizophrenic participants were less accurate in the recognition tests than the control participants and they did not show the revelation effect. In Experiments 1 and 2, the revelation effect occurred only for the control group when they responded to words or faces as the stimuli and gave confidence ratings. In Experiment 3, the revelation effect again did not occur for the schizophrenic group when they responded to words as the stimuli and gave ratings on whether their positive recognition decisions were based on recollection or based on familiarity; however, this was true for the control group as well, failing to replicate previous results. Similarly, in Experiment 4, the revelation effect did not occur for either group of participants when they responded to words as the stimuli and the critical recognition response was changed to "No" from "Yes". The results supported previous findings of impaired performance on word and face recognition tasks, as well as impaired effortful processing of new information in participants with schizophrenia. The results suggest that the revelation effect may require effortful processing of the distorted items and, as such, may not occur due to limited processing capacity.