精神分裂症谱系阴性症状特质人群快感缺乏的机制研究

PSYCH OpenIR > 健康与遗传心理学研究室

	精神分裂症谱系阴性症状特质人群快感缺乏的机制研究
其他题名	Anhedonia in Schizophrenia Spectrum Disorders
	王娇
	2016-05
摘要	快感缺乏是精神分裂症患者阴性症状临床核心表现之一。它不仅表现为对奖赏的愉快体验的下降，而且表现为奖赏动机的缺损。考察奖赏动机的研究表明，精神分裂症患者在低估奖赏金额的同时，会高估付出努力的程度，从而不倾向于选择高努力-高奖赏的任务。在愉快体验方面，期待和即时愉快体验在精神分裂症患者群体中是否存在缺损结果不一致。另外，已有研究发现精神分裂症患者的阴性症状越严重，奖赏动机缺损程度越高，但较少文献同时探讨阴性症状和奖赏动机和愉快体验的关系。本课题从精神分裂症谱系的角度，全面探讨阴性特质为主的分裂型特质个体、阴性症状为主的精神分裂症患者快感缺乏的行为机制，并以健康个体为样本，探讨正常的奖赏动机与愉快体验背后的脑机制。研究一考察阴性精神分裂症患者的快感缺乏在奖赏动机和愉快体验两个阶段上的行为机制。入组阴性精神分裂症患者22 名，非阴性精神分裂症患者18名以及29 名人口学属性变量相匹配的健康对照组。两组病人在病程方面相匹配。所有被试完成E-pet 任务，并且填写情绪相关问卷。结果发现：在奖赏决策阶段，与健康对照组相比，阴性精神分裂症患者不倾向于选择困难任务，而非阴性患者则无显著差异。具体来说，阴性精神分裂症患者随着奖赏概率、奖赏金额和估计奖赏金额的增加，选择困难任务比率并没有增加。所有精神分裂症患者选择困难任务的比率和Chapman 生理和社会快感缺失量表的得分呈显著负相关。在期待愉快体验阶段，阴性精神分裂症患者的期待愉快体验评分显著低于健康对照组，非阴性患者则与健康对照组没有显著差别。阴性精神分裂症患者随着奖赏概率、奖赏金额和估计奖赏金额的增加，期待愉快程度并不随之增加。精神分裂症患者期待愉快体验评分和期待与即时愉快体验分量表得分呈显著正相关；在即时愉快体验阶段，最终奖赏金额越高，体验到的愉快程度越高。但是阴性和非阴性精神分裂症患者、健康对照组的即时愉快体验程度并无显著差异。研究二考察阴性分裂型特质个体在奖赏动机和愉快体验的行为表现上是否也同样存在缺损。入组阴性分裂型特质组26 人，人口学属性变量相匹配的低分对照组28 人。实验材料和过程与研究一相同。阴性分裂型特质个体表现出和阴性精神分裂症患者较为相似的奖赏决策模式和情绪体验反应。在奖赏决策阶段，与低分对照组相比，阴性分裂型特质组不倾向于选择困难任务，而且选择困难任务的比率并不随着奖赏概率、奖赏金额和估计奖赏金额的增加而增加。所有被试选择困难任务的比率与自评问卷测得的愉快体验能力呈显著负相关。在期待愉快体验阶段，阴性分裂型特质组期待愉快体验能力显著低于低分对照组，也不随着奖赏概率、奖赏金额和估计奖赏金额的增加而增加。在即时愉快体验能力方面，阴性分裂型特质组和低分对照组不存在显著差异。实际奖赏金额越高，即时愉快体验评分则越高。研究三从奖赏决策与期待两个阶段初步探讨与奖赏动机相关的脑区活动，考察了30 名健康被试在完成E-pet 影像任务时的脑功能活动。结果发现，奖赏决策阶段，对奖赏概率信息敏感的脑区主要包括左侧前扣带回、右侧后扣带回、双侧额中回和额上回，奖赏金额相关的激活区域是右侧海马旁回。在奖赏期待时，奖赏概率主要激活左侧额中回，而期待奖赏金额经FDR 校正后无脑区被激活。从以上研究可以看出，精神分裂症谱系中以阴性症状为主的精神分裂症患者的快感缺乏主要集中体现在更多的与动机相关的成分，包括奖赏决策和奖赏期待。在即时愉快体验能力方面，阴性精神分裂症患者表现完好。在以阴性特质为主的分裂型特质个体中，即高危人群中也有类似的缺损表现。影像研究的结果从神经机制层面进一步揭示了奖赏决策主要和额中回和后扣带回区域的加工有关。奖赏期待时奖赏概率信息加工主要与额中回的激活有关。
其他摘要	Anhedonia, one of the core negative symptoms in schizophrenia, includes reduction both in motivation and hedonic capacity. However, previous studies only focused on either amotivation or reduced hedonic capacity. Moreover, negative symptoms have been found to be associated with reward amotivation in patients with schizophrenia. However, it is not clear how patients with schizophrenia characterized with negative symptoms would make an effort-expenditure choice when the reward value or probability increased. It is also unclear whether individuals with negative schizotypy would also demonstrate similar deficits with their clinical counterparts.The purpose of the present study was to examine the behavioural mechanism underlying the motivational anhedonia in schizophrenia patients and individuals with negative schizotypy. It also aimed to identify the neural mechanism of reward motivation and hedonic capacity in these individuals. Study1 examined the behavioral mechanism of reward motivation and pleasure experience in schizophrenia. Twenty-two schizophrenia patients with prominent negative symptoms (Neg-SCZ), 18 schizophrenia patients without prominent negative symptoms (Non-Neg-SCZ), and 29 healthy controls (HC) were recruited. All of them were administered the Effort Based Pleasure Experience Task（E-pet）task, which required the participants to make decisions on whether to choose a hard or an easy task based on probability and reward magnitude. After the task completion, participants rated anticipatory pleasure experience when expect potential reward.Finally, participants rated consummatory pleasure experience according to the obtained reward. When making the grip effort allocation decision, schizophrenic patients with prominent negative symptoms were significantly less likely to choose a hard task than healthy controls. As the reward magnitude and the estimated reward value increased, unlike healthy controls, schizophrenic patients with prominent negative symptoms did not increase their hard task choices. They were also significantly less likely to choose a hard task than healthy controls in medium and high probability conditions. When anticipating potential reward, these patients reported significantly less anticipatory pleasure than healthy controls, even when reward probability and magnitude increased. The pleasure experience rating after obtaining the actual reward was positively correlated with two pleasure experience scales in schizophrenic patients. Conclusively, patients with schizophrenia, especially those with prominent negative symptoms, showed deficits in both reward motivation and anticipatory pleasure experience for getting reward. Study2 examined whether the motivational anhedonia observed in clinical patients would be demonstrated in individuals with negative schizotypy. Twenty-six individuals with Neg-SPD and 28 healthy controls were recruited. E-pet were executed among all of them, the results indicated that negative schizotypy tend to choose less high effort high reward task than healthy control. The ratio of difficult task choice of negative schizotypy would not improve with the elevation of probability and reward magnitude when compared with healthy control. When anticipating reward, negative schizotypy reported less anticipatory pleasure experience than healthy control, even when probability level and anticipatory reward increased. Upon obtaining reward, negative schizotypy reported same extent of pleasure experience with healthy control. Study3 investigated the neural basis of reward motivation and reward anticipation in 30 healthy controls with a modified E-pet imaging paradigm. The result showed that the bilateral medial prefrontal cortex, the right anterior cingulated cortex, the left posterior cingulate cortex and the left prefrontal gyrus were responsible for the probability processing during decision making. Reward magnitude preprocessing was correlated with brain zone of the right hippocampus gyrus. In reward anticipation, the medial prefrontal gyrus was activated in high-low probability contrast. Taken together, the motivational anhedonia in individuals with schizophrenia spectrum disorders, especially those patient with prominent negative symptoms, centered on deficits in effort reward decision making and anticipation while consummatory pleasure experience remain intact. Imaging study further supported that the underlying neural mechanism of reward decision making was associated with the medial prefrontal gyrus and the posterior cingulate cortex. In reward anticipation phase, probability processing was associated with the activities in the medial prefrontal gyrus.
学科领域	认知神经科学
关键词	快感缺乏阴性症状精神分裂症分裂型特质奖赏动机
学位类型	硕士
语种	中文
学位专业	心理学
学位授予单位	中国科学院研究生院
学位授予地点	北京
文献类型	学位论文
条目标识符	http://ir.psych.ac.cn/handle/311026/19858
专题	健康与遗传心理学研究室
作者单位	中国科学院心理研究所
推荐引用方式 GB/T 7714	王娇. 精神分裂症谱系阴性症状特质人群快感缺乏的机制研究[D]. 北京. 中国科学院研究生院,2016.

条目包含的文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
王娇-硕士学位论文.pdf（2310KB）	学位论文		限制开放	CC BY-NC-SA	请求全文