结果评价受预期强度影响的事件相关电位研究

目的 探讨结果评价是否受预期的强度水平影响.方法 研究对象为16名在校大学生,使用NeuroScan ERP工作站采集、比较归因任务中,行为结果在四种预期强度水平下诱发的反馈相关负波(FRN),并对其进行偶极子溯源分析.结果 ①FRN由失钱的反馈诱发,得钱反馈后无明显FRN.②归责失钱诱发的FRN波幅(-6.24μV)大于归功失钱诱发的FRN波幅(-4.67μV),差异具有显著性(F(1,15)=26.42,P<0.001);归因对象在FRN波幅上主效应不显著.③FRN波幅在Fz区域最大从Fz到Pz依次为:(-7.55μV,-6.54μV,-5.20μV,-4.16μV,-3.83μV],差异具有显著性(F(2,8)=8.12,P<0.01).④偶极子溯源分析结果显示FRN的发生源可能位于扣带同附近(Talairach坐标:-16.3,-73.1,13.3;残差为1.98%).结论 FRN对负性行为结果敏感,且其波幅受预期强度水平影响,它可能反映了认知系统对不符合预期、且比预期糟的行为结果的评价加工.

Event-related potentials study on outcome evaluation affected by different intensity of expectation

Objective To reveal the nature of the outcome evaluation reflected by event-related potentials in evaluation process.Methods 16 College students were required to make attribution about their performance during a task,event-related potentials were recorded by NeuroScan ERP and dipole source location analyzed by Curry4.6.Results ①The feedback-related potential (FRN) was elicited by the negative outcomes.②The amplitude of the FRN was larger on the condition of fail to attribute the responsibility (-6.24μV) than the contribution (-4.67μV),there was significantly statistical meaning(F(1,15)=26.42,P<0.001).③The overall FRN magnitudes were more negative-going at Fz(+7.55μV) than Fcz(-6.54μV),Cz(-5.20μV),CPz(-4.16μV) and Pz(-3.83 μV),there was significantly statistical meaning(F(2,8)=8.12,P<0.01).④Dipole source location analysis showed that the neural generator of FRN may be the anterior cingulated cortex (ACC)(Talairach coordinates:-16.3,-73.1,13.3;residual variance:1.98%).Conclusion The feedback-related potential (FRN) is sensitive to the negative outcome, and affected by the intensity levels of the expectation for the outcome.FRN may reflect a evaluation process that the actual outcome is unexpected and worse than the expectation.