健康与遗传心理学研究室知识库

幽默加工是一种高级的社会认知功能，包含理解与精细化两个阶段。理解阶段指对不一致信息的觉察与解决，精细化阶段指对不一致信息的评价与随后的情绪体验。根据先前文献报告，精神分裂症患者幽默加工存在缺损，影响了患者的社会功能。但具体缺损在什么加工阶段尚未清晰，而且目前只有少数研究涉及精神分裂症患者幽默加工的脑功能机制，这种缺损相关的神经机制尚不完全清楚。

另外，快感缺失是精神分裂症阴性症状的核心症状之一，具有相似表现的社会快感缺失人群是精神分裂症谱系群体的亚临床人群，探究幽默加工的缺损是否在谱系群体的亚临床阶段就己经表现出来，对揭示幽默加工是否是精神分裂症早期识别指标具有理论意义。因此，本课题旨在探究精神分裂症患者和快感缺失群体的幽默加工认知与脑功能缺损机制。

研究一考察精神分裂症患者在理解与精细化阶段的幽默认知加工机制，65名精神分裂症患者和52名健康对照组被试完成了幽默加工图片和视频任务，通过信号检测论等方法分析，结果发现精神分裂症患者幽默加工的主要缺损表现为更高的虚报率，且虚报率与阴性症状呈现显著相关。结果说明精神分裂症患者在幽默理解阶段存在认知上的偏差，这种与他人不一致的认知偏差具有一定临床意义。

研究二考察精神分裂症患者幽默加工的脑神经机制，35名精神分裂症患者和35名健康对照组被试分别完成幽默对话判断任务的同时，进行功能磁共振成像扫描，行为结果发现精神分裂症患者的幽默信号辨别力更差，即幽默理解阶段的不一致信息觉察与解决存在缺损。影像结果发现精神分裂症患者加工幽默信息时，主要激活颗中回、海马旁回、额中回和下顶叶等区域，健康对照组在加工幽默信息时主要激活脑区为颗中回、后扣带回、颗下回、额下回和额上回等;与健康对照组相比，精神分裂症患者在尾状核和额中回的活动减弱。结果说明精神分裂症患者对文字笑话的加工主要缺损在语义相关的一些高级语言功能区，额中回和尾状核活动减弱可能是精神分裂症患者幽默加工缺损的神经基础。

研究三考察社会快感缺失群体幽默加工的脑神经机制，25名社会快感缺失个体和25名低分对照组均完成了幽默对话判断任务的功能磁共振成像扫描，行为结果发现社会快感缺失组当前的积极情绪、渝快体验、情绪的表达和幽默感均更差，影像结果发现在社会快感缺失群体中仅在后扣带回有活动，在低分对照组中颗中回和扣带回有活动，两组相比低社会快感缺失组缺少颗中回的激活。结果说明颗中回可能是社会快感缺失群体幽默加工缺损脑区，解释了他们幽默加工能力和愉快体验下降的可能原因，拓展了精神分裂症谱系的幽默加工研究。

本课题系统地从行为和功能影像角度揭示了精神分裂症患者幽默加工缺损的认知与神经机制。研究结果发现精神分裂症患者加工幽默信息时的缺损主要是对不一致信息的觉察和解决，尾状核和额中回活动减弱可能是相关的神经基础，在社会快感缺失个体中也发现了此阶段相关的颗中回的活动异常，从精神分裂症谱系的角度揭示社会快感缺失个体加工幽默信息时也存在缺损的神经机制。这些结果揭示了精神分裂症谱系群体幽默加工缺损的认知与神经机制，将信号检测论的分析方法应用在幽默加工不同阶段的数据分析中，为精神分裂症谱系社会认知研究提供新的参考。

Humour processing is a complex social cognitive function, including phases of comprehension and elaboration. Comprehension refers to the incongruity detection and resolution. Elaboration is the evaluation of inconsistent information and the subsequent emotional experience. Patients with schizophrenia have deficits in humour processing. Only a few studies examined the neural mechanism of humour processing in patients with schizophrenia. It is not clear their deficits exit in which phase and it would be very helpful to provide more empirical evidence to reveal its neural mechanism. In addition, previous studies showed that individuals with social anhedonia have attenuated but similar social cognitive function deficits with schizophrenia. But it is unclear what is the neural mechanism underlying humour processing in this subclinical population. This study aimed to investigate the cognitive deficits and the underlying neural mechanism of humour processing in patients with schizophrenia and its subclinical population.

Study 1 investigated the cognitive deficits of humour processing in patients with schizophrenia. Sixty-five patients with schizophrenia and 52 healthy control subjects were recruited to complete the humour processing tasks of picture and video. Based on the signal detection theory, the results showed that patients with schizophrenia falsely identified more nonhumour stimuli as humour stimuli than the control group.The false alarm rate was positively correlated with negative symptom. The results suggested the cognitive deficits of humour processing in patients with schizophrenia and its clinical correlation.

Study 2 examined the neural mechanism underlying the humour processing in schizophrenia. Thirty-five patients with schizophrenia and 35 healthy subjects completed a functional imaging task of humour processing. The behavioural results showed that the d' was significantly lower in schizophrenia, that is, they have deficits in the incongruity detection and resolution. The imaging results showed the activation in the middle frontal gyrus (MFG) and caudate were reduced in the patients with schizophrenia compared with healthy control. The results indicated that the reduced activity in the middle frontal gyrus and caudate was related to the neural mechanism underlying the deficits of humour processing in patients with schizophrenia.

Study 3 examined the neural mechanism underlying the humour processing in the individuals with social anhedonia. Twenty-five individuals with high social anhedonia and 25 individuals with low social anhedonia completed a functional imaging task of humour processing. We found the current positive emotion, pleasure experience, emotional expression and sense of humour were worse in individuals with high social anhedonia, and the posterior cingulate gyrus was activated in individuals with high social anhedonia. The middle temporal gyrus (MTG) and cingulate gyrus were showed activated in individuals with low social anhedonia. The individuals with high social anhedonia had a lack of activation of MTG compared with control group. The results show that MTG may be related to the deficits of humour processing in high social anhedonia group. This study provided some preliminary evidence of the neural mechanism underlying the humour processing deficits in schizophrenia spectrum disorders.

This study systematically reveals the cognitive and neural mechanism underlying the humour processing in patients with schizophrenia and the subclinical populations in schizophrenia spectrum disorders. The study found that the deficits of humour processing in patients with schizophrenia are mainly associated with the incongruity detection and resolution, and the underlying neural mechanism associated with these deficits were reduced activities in caudate and MFG. Individuals with high social anhedonia exhibited a lack of activation of MTG during humour processing compared with controls. The present study has based on the signal detection theory to examine the cognitive and neural mechanism underlying the deficits of humour processing in patients with schizophrenia and the subclinical population. It also shed light on the social cognitive function in schizophrenia and the pathological mechanism of negative symptoms.