Seeing is remembering: do deficits in closure affect visual memory recognition in schizophrenia?

Episodic memory is significantly impaired in people with schizophrenia. The precise cause of this impairment has yet to be determined, as the formation of episodic memories is dependent on other processes, some of which also show impairment in schizophrenia. One such process is closure, that is, the filling-in of missing information. Failure to close adequately incomplete stimuli may cause people with schizophrenia to store inadequate or piecemeal representations in memory.

Forty people with schizophrenia and 21 healthy comparison subjects participated in the study. The experiment was divided into six blocks, each of which involved both an encoding and a recognition phase. During the encoding phase, 20 figures were presented sequentially and participants had to determine whether each was symmetric or asymmetric. These figures were either complete or fragmented at three different levels. In subsequent recognition phase, 40 abstract figures (20 new and 20 old) were presented. All figures were complete in this phase.

Memory performance of both groups was affected similarly by fragmentation, with an additional increase in performance afforded by a slight fragmentation for participants with schizophrenia.

Slight fragmentation may have induced a perceptual difficulty that was mild enough to increase visual processing without compromising it. Closure was thus not involved in the episodic memory deficit of people with schizophrenia.