他人决策行为对个体风险决策的影响:基于静息态fMRI研究

目的采用改编的连续风险决策任务并结合静息态功能磁共振成像技术,探讨他人决策行为对个体情绪和风险决策的影响及其与个体静息态脑活动之间的关系。材料与方法采集被试的静息态脑功能成像数据并进行实验任务,任务中被试观看他人在连续风险决策中的行为与决策结果(分为好、一般、差3个条件),并基于个体感受对他人结果进行情绪评分,继而完成类似的风险决策,任务结束后收录被试填写的社会比较倾向量表。本研究利用被试对他人的不同决策结果的情绪评分差值来度量个体对他人决策结果的情绪敏感性;利用个体在参照他人不同决策结果后的风险决策行为改变差值来度量个体行为改变的敏感性;利用社会比较倾向量表测量个体的社会比较倾向。使用DPARSF处理静息态数据,计算左侧眶额叶皮层、右侧顶下小叶和双侧纹状体的功能连接值,同时计算大脑的局部一致性(regional homogeneity,ReHo),最后将对他人结果的情绪敏感性、行为改变敏感性和社会比较倾向分数分别与之做相关分析。结果左侧眶额叶皮层与右侧纹状体的功能连接与个体社会比较倾向呈正相关;左侧纹状体与右侧顶下小叶的功能连接与对他人的不同决策结果的情绪敏感性呈负相关;右侧眶额叶皮层的ReHo值与在他人不同决策结果后的风险决策中的行为改变敏感性呈负相关。结论静息条件下纹状体、顶下小叶及眶额叶皮层的功能连接以及眶额叶皮层的ReHo值与他人决策结果对个体情绪、后续决策的影响有关。

The impact of others' decision on individual risk-taking behavior:A rs-fMRI study

Objective:By combining the sequential risk taking task and the resting-state functional magnetic resonance imaging(rs-fMRI)technique,the current study tried to investigate the influence of others' risk-taking behavior on the individual's emotion and risk-taking behavior.Materials and Methods: After the scanning of rs-fMRI,participants were asked to finish the sequential risk taking task.In the each trial of the task,participants firstly could get the information of others' outcome.Others' outcomes were divided into good,general and poor conditions.Secondly,participants were asked to rate their feelings on a 9-point scale towards others' outcome.Finally,participants finished a similar risk-taking task.After the experiment,participants were asked to fill out the social comparison orientation scale.In the current study,we calculated three indexes to describe the individual differences:(1)The tendency of individual's social comparison,which was measured by the social comparison orientation scale.(2)The sensitivity of individual's emotion to others' outcomes,which was defined as the difference of the participants' emotional ratings towards others' different outcomes.(3)The sensitivity of individual's behavior changing to others' outcomes,which was defined as the difference of the participants' behavior changing after others' different outcomes.Besides,DPARSFA toolbox was used to calculate the functional connectivity(FC)among orbitofrontal cortex(OFC),striatum and inferior parietal lobule(IPL)and calculate the regional homogeneity(ReHo)value.Then,correlation analysis was conducted to examine the relationship between rs-fMRI data(FC and ReHo values)and the three indexes of individual differences.Results: The results showed that the tendency of individual's social comparison was positively correlated with the functional connectivity between left OFC and right striatum.Moreover,the sensitivity of individual's behavior changing to others' outcomes was negatively correlated with the functional connectivity between left striatum and right IPL.In addition,the sensitivity of individual's behavior changing to others' outcomes was negatively correlated with the ReHo value of right OFC.Conclusions: The functional connectivity among OFC,striatum and IPL,as well as the ReHo value of OFC are associated with the impact of others' outcomes on individual's emotion and risk-taking behavior.