가상환경을 이용한 일화기억 인출에서 조현병 환청군과 비환청군의 신경 진동의 차이

Abstract

Neural correlates of episodic memory deficits may be different in schizophrenia patients with hallucinations (SH) and patients without hallucinations (SnH). However, little is known about how specific neural correlates involved in episodic retrieval may differ between SH and SnH. We aimed to determine whether neural oscillations in SH during episodic retrieval are different from those in SnH and normal controls (NC) after navigating rooms in a virtual environment (VE). The VE was used to enhance patient motivation in episodic memory test by engaging higher cognitive involvement. Subjects experienced a navigation session and a retrieval session. Electroencephalogram (EEG) was recorded during the retrieval session, and time-frequency analyses were examined (7 NC, 7 SnH, and 7 SH). Consistent with previous reports, the results revealed that theta power was correlated with successful episodic retrieval, suggesting that the reductions of theta power may contribute to episodic memory deficits in SH and SnH. Notably, the theta power differences between the old and new conditions was positively correlated with episodic retrieval performances across SH, SnH, and NC. Other oscillatory activities (i.e., alpha and beta) may also contribute to episodic retrieval with a diversity of functional relevance across groups. Overall results showed deficits in episodic retrieval, corresponding oscillations in EEG frequency bands. The neural oscillations across different frequencies and their relationship to cognitive processes, including inhibition and attention in episodic memory, are also discussed.