Working Memory Deficits in Ultra-High Risk for Psychosis and Schizophrenia.

Jeon, Im Hong; Park, Jong Suk; Park, Jin Young; Cho, Hye Hyun; Koo, Se Jun; Lee, Eun; An, Suk Kyoon; Yoo, Sun Kook

doi:2012.15.2.66

Korean J Schizophr Res > Volume 15(2); 2012 > Article

Original Article

Korean Journal of Schizophrenia Research 2012;15(2):66-72.
DOI: https://doi.org/10.16946/kjsr.2012.15.2.66 Published online October 31, 2012.

Working Memory Deficits in Ultra-High Risk for Psychosis and Schizophrenia.

Im Hong Jeon, Jong Suk Park, Jin Young Park, Hye Hyun Cho, Se Jun Koo, Eun Lee, Suk Kyoon An, Sun Kook Yoo

¹Department of Psychiatry, Yonsei University College of Medicine, Severance Mental Health Hospital, Seoul, Korea. ansk@yuhs.ac
²Section of Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, Korea.
³Department of Psychiatry, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea.
⁴Department of Psychiatry, Yonsei University College of Medicine, Severance Hospital, Seoul, Korea.
⁵Department of Medical Engineering, Yonsei University College of Medicine, Seoul, Korea.

Abstract

OBJECTIVES
The aim of this study was to investigate whether verbal and spatial working memory functions were impaired not only in patients with schizophrenia but also in people at ultra-high risk for first-episode psychosis.
METHODS
Twenty-five patients (M 13, F 12) with schizophrenia (SPR), 21 people at ultra-high risk for psychosis (UHR)(M 10, F 11) and 19 normal controls (NC)(M 10, F 9) were recruited. The working memory was assessed by using the verbal and spatial n-back test. The working memory load increased incrementally from the 0-back to the 3-back condition.
RESULTS
SPR performed significantly lower than NC and UHR in terms of hit rates of verbal and spatial n-back test. UHR subjects conducted significantly lower than NC and higher in trend-level than SPR in terms of hit rates of verbal and spatial n-back test. These differences were derived from the high working memory load (2-back and 3-back), not from the low working memory load (0-back and 1-back). There was no significant difference between the verbal and spatial n-back test across the three groups.
CONCLUSION
These findings suggest that verbal and spatial working memory dysfunction may be general rather than differential in terms of stimuli modality, and this working memory deficit may be an important trait factor in schizophrenia.

Key Words: Verbal · Spatial · Working memory · N-back test · Ultra-high risk for psychosis · Schizophrenia