Contribution of working memory components to the performance of the tower of Hanoi in schizophrenia

Abstract

Objectives: To examine the underlying structure of neuropsychological tests involving working memory components and those not involving working memory components that contribute to the performance of the Tower of Hanoi task in schizophrenic patients. Participants and Methods: A total of 90 patients with residual schizophrenia received a comprehensive cognitive assessment. Working memory was assessed with Letter-Number Span and Visual Patterns tests. Executive function was assessed by the Tower of Hanoi task. Stepwise multiple linear regressions were performed including age, education, duration of illness, and all cognitive functions. Results: Principal component analysis was conducted and yielded a 4-factor solution: auditory working memory, visual working memory, verbal working memory, and verbal fluency. Subsequent stepwise regression indicated that only visual working memory components and auditory working memory components were retained in the final model accounting, which explained 23.5% of the variance. Conclusions: These findings emphasise the importance of memory components, particularly those involving visual- and auditory-based working memory, when conceptualising the performance of the Tower of Hanoi task in residual schizophrenia. © 2010 Hong Kong College of Psychiatrists.