结果评价受预期强度影响的事件相关电位研究

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

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回附近（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。

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 （ - 6.24 μV） than the contribution （ -4.67 μV）, there was significantly statistical meaning（F （1.15）= 26.42, P 〈 0. 001 ）. ③The overall FRN magnitudes were more negative-going at Fz（ -7.55 μV） than Fcz （ -6.54 μV）, Cz（ -5.20 μV） , CPz （ -4.16 μV） 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.