Hippocampus and nucleus accumbens activity during neutral word recognition related to trait physical anhedonia in patients with schizophrenia: An fMRI study

한글 요약

조현병 환자의 무쾌감증, 즉 즐거움을 느끼지 못하는 증상이 감정 기억의 이상과 관련이 있는지를 fMRI로 살핀 연구입니다. 조현병 환자와 건강한 대조군이 중립 단어를 긍정적 또는 중립적 이미지와 함께 학습한 뒤 단어를 재인하는 과제를 수행했고, 편도체, 해마, 측좌핵, 복내측 전전두엽 등 감정 기억 관련 영역의 신호 변화와 신체적 무쾌감증 척도의 상관을 분석했습니다. 재인 정확도와 반응 시간에는 집단 차이가 없었지만, 환자군에서만 해마와 측좌핵의 활성이 무쾌감증 점수가 높을수록 낮아지는 음의 상관이 나타났습니다. 해마와 측좌핵이 조현병의 기질적 신체 무쾌감증에 관여하며, 감정 기억 결손과 무쾌감증이 서로 연관될 가능성을 뒷받침하는 결과입니다.

Emotional memory dysfunction may be associated with anhedonia in schizophrenia. This study aimed to investigate the neurobiological basis of emotional memory and its relationship with anhedonia in schizophrenia specifically in emotional memory relate brain regions of interest (ROIs) including the amygdala, hippocampus, nucleus accumbens, and ventromedial prefrontal cortex. Fourteen patients with schizophrenia and 16 healthy subjects performed a word-image associative encoding task, during which a neutral word was presented with a positive, neutral, or control image. Subjects underwent functional magnetic resonance imaging while performing the recognition task. Correlation analyses were performed between the percent signal change (PSC) in the ROIs and the anhedonia scores. We found no group differences in recognition accuracy and reaction time. The PSC of the hippocampus in the positive and neutral conditions, and the PSC in the nucleus accumbens in the control condition, appeared to be negatively correlated with the Physical Anhedonia Scale (PAS) scores in patients with schizophrenia, while significant correlations with the PAS scores were not observed in healthy subjects. This study provides further evidences of the role of the hippocampus and nucleus accumbens in trait physical anhedonia and possible associations between emotional memory deficit and trait physical anhedonia in patients with schizophrenia.