不同时间洞察力个体的跨期选择偏好及神经机制研究

发布时间：2018-06-24 15:38

本文选题：跨期选择 + 时间洞察力　；参考：《西南大学》2014年硕士论文

【摘要】：跨期选择(intertemporal choice)是指个体对发生在不同时间点的成本与收益进行权衡,而后做出的各种判断和选择(Loewenstein,1988; Frederick, Loewenstein,O'Donoghue,2002)。现实生活中,小到个人的储蓄、健康和工作,大到国家的教育投资、环境保护等政策,都不可避免地遇到跨期选择问题。因此,跨期选择的研究有助于人们做出更加理性、更加科学的判断或决策。最近,有研究者从感知时间基础模型(Perceived-time-based model)的角度来解释跨期选择中的时间折扣现象(KimZauberman,2009):个体对时间维度和时间压缩水平的敏感性是影响延迟折扣的主要原因之一。那么,在跨期选择中,不同时间洞察力的个体是否具有不同的选择偏好呢?其认知机制和神经基础是什么呢?为此,本研究利用行为实验和静息态功能核磁共振成像(rs-fMRI)技术,从时间洞察力角度出发,采用跨期选择经典行为范式,主要研究两个问题：(1)不同时间洞察力个体的跨期选择偏好的特点；(2)时间洞察力影响跨期选择的神经基础与运行机制。为此本研究分两个实验研究,结果如下。研究一采用行为实验,选取两类不同时间洞察力倾向(“未来时间”倾向和“享乐现在”倾向)的个体,通过标准的跨期选择任务,考察他们在跨期选择上的偏好和特点。结果发现：(1)与“未来时间”洞察力组相比,“享乐现在”时间洞察力组的延迟折扣率更高,更偏好即时满足；(2)未来时间洞察力组在“未来时间洞察力维度”的得分与延迟折扣率负相关,即未来时间洞察力定向越强,延迟折扣率就越低。这些结果说明,不同时间洞察力倾向的个体在跨期选择上具有不同的偏好,未来时间洞察力能够较好地预测个体延迟折扣。然而,时间洞察力又是如何影响到个体的跨期选择的呢?其背后的认知神经机制是什么呢?为此,本研究采用rs-fMRI技术,从神经基础和功能网络角度开展了研究二。研究二采用静息态功能磁共振成像技术(rs-fMRI),考查时间洞察力影响跨期选择的神经基础与运行机制：重点从时间网络、价值评估网络和认知控制网络出发,探究了时间洞察力对跨期选择的调控机制。行为结果进步验证了研究一的结论：曲线下面积(AUC；延迟折扣率=1-AUC)与“未来时间”维度得分正相关,而与“享乐现在”维度得分负相关。静息态的研究结果表明：(1)延迟折扣曲线下面积(AUC)和前扣带回(ACC)与背外侧前额叶(d1PFC)间功能连接强度负相关；(2)前扣带回(ACC)与背外侧前额叶(d1PFC)间功能连接变化量与“享乐现在”维度得分正相关,而与“未来时间”维度得分负相关；(3)中介分析表明,ACC-L.d1PFC之间功能连接在时间洞察力对跨期选择的影响中起到了部分中介作用。这些结果说明,前扣带回(ACC)与背外侧前额叶(d1PFC)之间的功能连接在时间洞察力对跨期选择的影响中起到关键的作用,也就是说时间洞察力对跨期选择很可能是通过认知控制在起作用。综合而言,研究发现：(1)不同时间洞察力个体具有不同的跨期选择偏好,“享乐现在”倾向的个体更倾向于即时满足,而“未来时间”倾向的个体更倾向于延迟满足；(2)背外侧前额叶(d1PFC)与前扣带(ACC)之间的功能连接在时间洞察力对跨期选择的影响中起到重要的中介作用。本研究从时间洞察力这种人格特质出发,考察了跨期选择的认知机制与神经基础,不仅拓宽了跨期选择的研究领域,也为探究跨期选择的认知神经机制提供了新的视角；其实践应用价值也显而易见。
[Abstract]:Intertemporal choice refers to the individual ' s trade - offs between costs and benefits that take place at different points of time , and then various judgments and choices ( Loewenstein , 1988 ; Frederick , Loewenstein , O ' Donghue , 2002 ) . In real life , small to individual savings , health and work , big to the country ' s education investment , environmental protection and other policies inevitably meet the cross - period choice problem . Therefore , the study of cross - period selection can help people make more rational and scientific judgment or decision - making .
( 2 ) The time - insight influence the neural basis and operation mechanism of cross - stage selection . For this purpose , two experimental studies are conducted , the results are as follows .

It is found that : ( 1 ) Compared with the " future time " insight group , the delay discount rate of the " pleasure present " time insight group is higher , and the preference for immediate satisfaction is more preferred .
( 2 ) There is a negative correlation between the score of the future time insight group and the delay discount rate , that is , the higher the future time insight is , the lower the delay discount rate . These results show that individuals with different time insight tend to have different preferences in the cross - period selection , and the future time insight can better predict individual delayed discounts .

Based on the time network , the value assessment network and the cognitive control network , the study explored the mechanism of time insight to the selection of cross - period . The results of the study demonstrate the conclusion that the area under the curve ( AUC ;
The delayed discount rate = 1 - AUC was positively correlated with the " future time " dimension score , while negative correlation with " pleasure present " dimension score . The results of the study of resting state showed that ( 1 ) the area under the delayed discount curve ( AUC ) and the frontal gyrus ( ACC ) were negatively correlated with the functional connection strength between the dorsolateral frontal lobe ( d1PFC ) ;
( 2 ) The change of functional linkage between the front buckle ( ACC ) and the dorsolateral frontal lobe ( d1PFC ) was positively correlated with the score of the " pleasure present " dimension , while negatively correlated with the " future time " dimension score ;
( 3 ) The intermediate analysis shows that the function connection between ACC - L . d1PFC plays a role in the influence of time insight into the influence of span selection . These results show that the function connection between ACC and d1PFC plays a key role in the influence of time insight into the influence of cross - period selection , that is , temporal insight may play a key role in cross - period selection .

Overall , it is found that : ( 1 ) individuals with different time insight tend to have different cross - stage selection preferences , and individuals who tend to " enjoy the right now " tend to be satisfied with immediate satisfaction , while individuals with " future time " tend to be more likely to delay satisfaction ;
( 2 ) The function connection between the dorsolateral frontal lobe ( d1PFC ) and the front buckle ( ACC ) plays an important role in the influence of time insight into the influence of cross - period selection .
Its practical application value is also obvious .
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：B842

【参考文献】