个体对效价预期和风险评估的时程加工机制:来自ERP的证据

采用事件相关电位技术(ERP),通过简单赌博任务,操纵结果预期的效价(输或赢)与风险(高风险与低风险),考察了个体对结果预期阶段的效价和风险评估的脑内时程动态加工过程。脑电结果发现:(1)在N2成分上,结果预期的效价主效应显著,预期输比预期赢能够引起更大的N2波幅;结果预期的风险主效应不显著。(2)在N500成分上,效价与风险之间的交互作用边缘显著,进一步简单效应分析发现,在预期输的条件下,肯定会输的N500波幅显著大于可能会输;而在预期赢的条件下,肯定会赢与可能会赢之间的N500波幅差异不显著。这说明,在不确定决策过程中的结果预期阶段,个体可能先对结果预期的效价进行加工,然后再对风险进行评估。

The Assesement Process of Anticipated Valence and Risk:Evidence from an ERP Study

An event-related potential(ERP)recording protocol was adopted to measure the timing process of outcome anticipation and risk assessment,while participants performed a simple gambling task in which the valence(loss or win)and the risk(high risk or low risk)were manipulated.Our results showed that:(1)The difference between the amplitudes of N2(in 320-370ms intervals)elicited by valence was significant,loss gave rise to greater N2 component;while the amplitudes of N2 elicited by risk showed no significant difference.(2)For N500(in 470-520ms intervals),the interaction between valence and risk was marginal significance;Simple effect analysis indicated that only in loss condition,the low-risk-related N500 was larger than the high-risk-related;however,there was no significant difference in win condition.To summarize,these results demonstrated that during the controlled process of outcome anticipation in the uncertainty decision-making,the valence of anticipation was processed first,and risk assessment second.