概率贴现和时间贴现在人脑中的分离  

Dissociation between Probability Discounting and Temporal Discounting in the Human Brain

作　　者：陈欣欣[1] 余荣军[2] 邓志洲[2] 王穗苹[2] 

机构地区：[1]中山大学管理学院,广州510275 [2]华南师范大学心理学院,广州510631

出　　处：《心理科学》2014年第6期1313-1320,共8页Journal of Psychological Science

基　　金：教育部人文社科重点基地项目(10JJDXLX005);华南师范大学广东省心理健康与认知科学重点实验室的资助

摘　　要：本研究运用ERP技术来检验概率贴现和时间贴现是否反映了相同的神经机制过程。在本研究中,我们在一个刺激中同时操纵概率贴现(风险vs.安全)和时间贴现(1个月后vs.今天)水平。通过对两个过程上的ERN以及全时间段的ERP分析来确定它们是否反映了相同的认知过程。结果发现,这两者在ERN上存在差异,同时这两个效应在ERP的时程和出现的电极点上都存在差异。这些差异表明这两者可能包含着不同的神经机制过程。Probability discounting and temporal discounting are important phenomena in people＇s daily economic decision making. Probability discounting occurs when people make a choice between different risky options. People tend to have a preference for the safe option in risky decision making. Temporal discounting refers that people tend to discount future benefits when facing decisions involving a smaller immediate gain and a larger future one. In recent years, researchers have had a strong interest in the relationship between probability discounting and temporal discounting. One hypothesis is that delayed rewards options might be evaluated as risky choices, leading to people＇s preference for the prompter payoff option in inter- temporal choice tasks. This hypothesis has been supported by some behavioral studies. However, several behavioral studies challenge the single- process explanation. These behavioral studies revealed inconsistent conclusions for the hypothesis. The fMRI studies also suggested the dissociation between probability discounting and temporal discounting. However, the fMRI evidences are based on separate studies using different paradigms. We employed event-related potential （ERP） to explore whether probability discounting and temporal discounting reflected the same underlying process. ERP can provide a continuous measure of mental processing, making it possible to get a clear evidence for this question. The present study recorded ERPs while participants performed a modified version of the ＂Wheel of Fortune＂ gambling task. In the task, probability factor （Risky vs. Safe） and temporal factor （One Month vs. Today） was permuted to form four conditions： Today ＆ Safe, Today ＆ Risky, Month ＆ Safe, and Month ＆ Risky. The study design yielded four conditions based on the participants＇ selections. Previous ERP studies on probability discounting have identified the error-related negativity （ERN） as a key index of probability discounting. While the ERP studies on temporal d

关 键 词：概率贴现 时间贴现 事件相关电位(ERP) 错误相关负波(ERN) 

分 类 号：R338[医药卫生—人体生理学]