Douglas Mental Health University Institute, 6875 LaSalle Boulevard, Montréal, Québec H4H 1R3, Canada.
Schizophr Bull. 2013 May;39(3):617-28. doi: 10.1093/schbul/sbs042. Epub 2012 Mar 26.
Empathic deficits in schizophrenia may lead to social dysfunction, but previous studies of schizophrenia have not modeled empathy through paradigms that (1) present participants with naturalistic social stimuli and (2) link brain activity to "accuracy" about inferring other's emotional states. This study addressed this gap by investigating the neural correlates of empathic accuracy (EA) in schizophrenia.
Fifteen schizophrenia patients and 15 controls were scanned while continuously rating the affective state of another person shown in a series of videos (ie, targets). These ratings were compared with targets' own self-rated affect, and EA was defined as the correlation between participants' ratings and targets' self-ratings. Targets' self-reported emotional expressivity also was measured. We searched for brain regions whose activity tracked parametrically with (1) perceivers' EA and (2) targets' expressivity.
Patients showed reduced EA compared with controls. The left precuneus, left middle frontal gyrus, and bilateral thalamus were significantly more correlated with EA in controls compared with patients. High expressivity in targets was associated with better EA in controls but not in patients. High expressivity was associated with increased brain activity in a large set of regions in controls (eg, fusiform gyrus, medial prefrontal cortex) but not in patients.
These results use a naturalistic performance measure to confirm that schizophrenic patients demonstrate impaired ability to understand others' internal states. They provide novel evidence about a potential mechanism for this impairment: schizophrenic patients failed to capitalize on targets' emotional expressivity and also demonstrate reduced neural sensitivity to targets' affective cues.
精神分裂症患者可能存在同理心缺陷,从而导致社交功能障碍,但以往对精神分裂症的研究并未通过既能(1)向参与者呈现自然的社会刺激,又能(2)将大脑活动与推断他人情绪状态的“准确性”联系起来的范式来模拟同理心。本研究通过调查精神分裂症患者同理心准确性(EA)的神经相关性来解决这一差距。
15 名精神分裂症患者和 15 名对照者在观看一系列视频(即目标)时,持续对另一个人的情绪状态进行评分。将这些评分与目标的自我评分进行比较,将 EA 定义为参与者评分与目标自我评分的相关性。还测量了目标自我报告的情绪表达。我们搜索了与(1)感知者的 EA 和(2)目标的表达性参数相关的大脑区域。
与对照组相比,患者的 EA 降低。与对照组相比,左顶叶下小叶、左中额回和双侧丘脑与 EA 的相关性更强。目标的高表达性与对照组的 EA 更好相关,但与患者无关。在对照组中,高表达性与大脑活动的增加相关,涉及多个区域(例如梭状回、内侧前额叶皮质),但在患者中则没有。
这些结果使用自然表现测度来证实精神分裂症患者在理解他人内部状态方面的能力受损。它们提供了有关这种损害的潜在机制的新证据:精神分裂症患者未能利用目标的情绪表达,并且对目标的情感线索的神经敏感性也降低。