Visuospatial imagery and working memory in schizophrenia

Abstract

Introduction

The ability to form mental images that reconstruct former perceptual experiences is closely related to working memory (WM) ability. However, whereas WM deficits are established as a core feature of schizophrenia, an independent body of work suggests that mental imagery ability is enhanced in the disorder. Across two experiments we investigated mental imagery in schizophrenia and its relationship with WM.

Methods

In Experiment 1, individuals with schizophrenia (SZ: n=15) and matched controls (CO: n=14) completed a mental imagery generation and inspection task and a spatial delayed-response WM task. In Experiment 2, SZ (n=16) and CO (n=16) completed a novel version of the mental imagery task modified to increase WM maintenance demand.

Results

In Experiment 1, SZ demonstrated enhanced mental imagery performance, as evidenced by faster response times relative to CO, with preserved accuracy. However, enhanced mental imagery in SZ was accompanied by impaired WM as assessed by the delayed-response task. In Experiment 2, when WM maintenance load was increased, SZ no longer showed superior imagery performance.

Conclusions

We found evidence for enhanced imagery manipulation in SZ despite their WM maintenance deficit. However, this imagery enhancement was abolished when WM maintenance demands were increased. This profile of enhanced imagery manipulation but impaired maintenance could be used to implement novel remediation strategies in the disorder.

Keywords:

• mental imagery
• schizophrenia
• working memory

Acknowledgements

We would like to thank Heath Nichols, Amanda Cumming, Randy Minas, and Jejoong Kim for their help.

Funding

This work was supported in part by NIH [MH073028] to SP and NIH [HD015052] to the Vanderbilt Kennedy Center.

Additional information

Funding

Funding: This work was supported in part by NIH [MH073028] to SP and NIH [HD015052] to the Vanderbilt Kennedy Center.