Eye-movement behavior reveals relational memory impairment in schizophrenia

Background: Previous studies have demonstrated impaired relational memory in schizophrenia. We studied eye-movement behavior as an indirect measure of relational memory, together with forced-choice recognition as an explicit measure. Methods: Thirty-five patients with schizophrenia and 35 healthy participants were trained to associate a face with a background scene. During testing, scenes were presented as a cue and then overlaid with three previously studied faces. Participants were asked to recall the matching face, and both eye movements and forced-choice recognition were recorded. During Non-Match trials, no faces matched the scene. During Match trials, one of the faces had previously been paired with the scene. Results: On Non-Match trials, when no relational memory trace was present, both groups viewed the three faces equally. In contrast, on Match trials, control participants quickly (within 500 msec) and consistently (70%75% of test trial viewing) showed preferential viewing of the matching face. Viewing of the matching face was significantly delayed and reduced in schizophrenia participants. Forced-choice recognition of the matching face was also impaired in the patient group. An analysis of all correct Match trials revealed that preferential viewing was significantly reduced and delayed in participants with schizophrenia. Conclusions: This study provides novel evidence for a specific relational memory impairment in schizophrenia. Patients showed deficits in their forced-choice recognition responses, as well as abnormal eye-movement patterns during memory recall, even on trials when behavioral responses were accurate. We propose that eye movements provide a promising new avenue for studying relational memory in schizophrenia.