T44. USING A VISUOSPATIAL MNEMONIC TO IMPROVE MEMORY IN PSYCHOSIS: A FEASIBILITY STUDY

Abstract

Background: Episodic memory is severely impaired in psychosis, compromising daily living activities and psychosocial functioning. Despite being one of the strongest predictors of psychosocial functioning, memory performance shows only small to moderate improvement following psychosocial interventions. The use of encoding strategies (e.g., forming a story, mental imagery, or using categories to link words) results in a richer memory- trace that increases recall when compared to thinking about the word's visual features or using repetition. However, people with psychosis tend not to spontaneously generate efficient strategies to facilitate recall. When trained in strategies such as semantic organization, they tend to show better outcomes in episodic memory performance. We investigated the effectiveness and feasibility of a visuospatial mnemonic strategy, the method of Loci (MoL), for improving episodic memory in psychosis. MoL takes advantage of mental visualization to facilitate encoding of disparate pieces of information, by relying on the "mental" allocation of the items to be memorized in several places. The efficacy of MoL and superiority over other mnemonics has been demonstrated in healthy subjects, and in older adults and depression; however, no study to date has evaluated the use of MoL in psychosis. Method(s): We developed a short intervention to investigate whether MoL could improve memory performance in psychosis. It involved free recall of two 20-item (psychosis group) or 25-item (healthy control group) lists then, following MoL training, the encode and recall of two new lists using MoL. Forty healthy controls and five psychosis patients successfully completed the study. Result(s): In healthy individuals, there was a significant improvement in recall of 2.8 items (SD = 4.1) after learning the MoL (t(39) = 4.2, p<0.001). No significant effect of MoL on recall was observed in the psychosis group (mean difference: 1.1, SD = 3.1; t(4) = 0.77, p>.05). All psychosis patients but one reported difficulty remembering their loci or their loci order during the post-test feasibility interview. Discussion(s): In contrast to the control group, the psychosis group did not improve in episodic memory recall after learning the MoL. During the sessions, it was evident that the complexity of MoL, along with its heavy reliance on working memory and mental visualization, hindered mastering the strategy, resulting in fatigue and consequent stagnation or slight decrease in memory performance during the post-test. Our results resonate with some previous findings in which psychosis patients might benefit less than controls from visuospatial mnemonic strategies and that populations with reduced cognitive reserve capacity may fail to engage in task-appropriate processing that prevents them from successfully implementing MoL. We conclude that MoL might not be appropriate to people with psychosis experiencing specific cognitive deficits such as in executive functioning, and mental imagery. Future research should investigate MoL's efficacy across a range of cognitive capacity in psychosis and assess less complex strategies (e.g. unitization), which are effective in populations with similar severity of cognitive deficits as those found in psychosis.