心理科学
心理科學
심이과학
Psychological Science
2014年
6期
1313~1320
,共null页
陈欣欣 余荣军 邓志洲 王穗苹
陳訢訢 餘榮軍 鄧誌洲 王穗蘋
진흔흔 여영군 산지주 왕수평
概率贴现 时间贴现 事件相关电位(ERP) 错误相关负波(ERN)
概率貼現 時間貼現 事件相關電位(ERP) 錯誤相關負波(ERN)
개솔첩현 시간첩현 사건상관전위(ERP) 착오상관부파(ERN)
probability discounting, temporal discounting, event related potential (ERP), error-related negativity (ERN)
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。
本研究運用ERP技術來檢驗概率貼現和時間貼現是否反映瞭相同的神經機製過程。在本研究中,我們在一箇刺激中同時操縱概率貼現(風險vs.安全)和時間貼現(1箇月後vs.今天)水平。通過對兩箇過程上的ERN以及全時間段的ERP分析來確定它們是否反映瞭相同的認知過程。結果髮現,這兩者在ERN上存在差異,同時這兩箇效應在ERP的時程和齣現的電極點上都存在差異。這些差異錶明這兩者可能包含著不同的神經機製過程。
본연구운용ERP기술래검험개솔첩현화시간첩현시부반영료상동적신경궤제과정。재본연구중,아문재일개자격중동시조종개솔첩현(풍험vs.안전)화시간첩현(1개월후vs.금천)수평。통과대량개과정상적ERN이급전시간단적ERP분석래학정타문시부반영료상동적인지과정。결과발현,저량자재ERN상존재차이,동시저량개효응재ERP적시정화출현적전겁점상도존재차이。저사차이표명저량자가능포함착불동적신경궤제과정。
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 discounting showed inconsistent ERP components. We would examine whether the ERN effect would also appear in the temporal discounting process. In order to get the accurate conclusion, we also analyzed all the ERP components of the two processes. We then first examined whether the ERN can also be elicited by choices involving delays. We found that the ERN elicited by the Risky choice was more negative than that elicited by the Safe one, whereas ERN for Month choices did not differ from ERN for Today choices. We then found the different distributions of time process and the electrode between the two processes. Specially, probability discounting occurred in time window of -100-50ms on FCz and time window of 100-350ms on Pz, while the temporal discounting occurred in time window of 200-600ms on Pz.
In conclusion, the current study showed that the probability discounting effect (Risky vs. Safe) and the temporal discounting effect (Month vs. Today) had different patterns in ERP waveforms. The differences suggested that the two processes may involve different neural mechanisms.