Visual memory errors in schizophrenic patients with auditory and visual hallucinations

Hallucinations have been found associated with false detection or false recognition of acoustic/verbal material in several studies. We investigated whether they were also linked with false recognition of pictures. Furthermore, an association between hallucinations and deficits in remembering temporal context was observed in previous research on schizophrenia. We investigated whether the association extends to deficits in remembering spatial context. Forty-one patients with schizophrenia underwent a visual memory task. Sixteen mixed black-and-white and colored pictures were presented at different locations. Participants had to recognize the pictures among distractors, then to recall the spatial context of the presentation of the target pictures. Results showed that auditory hallucinations were associated with poor recognition of the colored pictures. When recognition efficiency and negative symptoms were statistically controlled, auditory hallucinations were also associated with increased response bias toward false recognition of nontarget pictures, and with errors in remembering the spatial context. No associations with visual hallucinations emerged. Anhedonia was associated with response bias, in the direction opposite to that of hallucinations. In conclusion, the association between hallucinations and response bias extends across modalities to picture recognition. The association between hallucinations and temporal context impairment extends to spatial context.