Data showing how schizophrenia patients tend to be more susceptible to false memories have been rather mixed and, as far as we know, no studies have investigated whether patients with a schizophrenia spectrum disorder are particularly prone to imagination inflation effects, that is, whether repeatedly imagining an action increases the likelihood of remembering the action as having been performed. In this study, a group of patients with psychosis and a group of normal controls were asked to perform or to imagine performing simple action statements one or four times in a single study session. In a test session that occurred 24 h later, participants were instructed to discriminate whether the action statement had been carried out, imagined or whether it was new (a source monitoring task). The primary finding was that patients were more susceptible to source-monitoring errors than controls, especially in terms of considering an imagined action as having been performed. However, both groups showed comparable levels of imagination inflation effects. Results add evidence to the hypothesis that the nature of patients' false memories may be particularly linked to poor use of source-monitoring processes.
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