Sexual dimorphism of spatial working memory profiles in schizophrenia

Abstract

Introduction. The aim of the present study was to compare spatial working memory performance of females and males schizophrenia patients to verify whether the sexual dimorphism of spatial abilities present in the general population is found also in schizophrenia.

Methods. We analysed different types of errors committed by each gender on the spatial working memory test of the Cambridge Neuropsychological Test Automated Battery to determine potential differences between them.

Results. Despite the lack of difference in the number of errors between men and women, different profiles of errors were associated with the strategy used according to gender. The men's strategy was better compared to women. Specifically, for women strategy score correlated positively with searches in previously visited boxes, whereas for men it correlated with both previously visited boxes and never visited ones. However, men's strategy is more impaired by the number of revisits in boxes in which tokens have previously been found than female's one.

Conclusions. These results suggested impaired either central executive and/or visuospatial sketchpad of working memory in patients with schizophrenia. We demonstrated also that the worsening of strategy in men is principally due to central executive deficits compared to women with schizophrenia. The study of sex differences in cognitive performances could help in delineating partially different endophenotypes of schizophrenia in men and women.

Keywords:

• Endophenotype
• Gender
• Schizophrenia
• Sexual dimorphism
• Working memory

Acknowledgements

LL was supported by a grant received from the Chaire de Schizophrénie Eli Lilly de l'Université de Montréal, Québec, Canada. The authors are grateful to the two anonymous reviewers for their helpful comments to improve the original manuscript.