Vrije Universiteit Brussel, Belgium.
Brain Res. 2011 Oct 18;1418:83-92. doi: 10.1016/j.brainres.2011.08.067. Epub 2011 Sep 2.
Past research on spontaneous trait inferences using event related potentials (ERPs) has consistently reported increased late positive potential (LPP) amplitudes following social expectancy violations, but no N400 modulation. In the present study, participants read scenarios describing behaviors of unknown actors. They entailed descriptions of several positive trait implying behaviors, followed by a single final sentence describing behavior that was either consistent or inconsistent with the previously implied trait. As in previous studies, we found significantly increased LPP amplitudes following inconsistent behaviors at multiple frontal sites. Unlike in previous research, we also found increased N400 amplitudes at several centro-parietal sites. The divergence of these results is explained from minor differences in the stimulus presentation procedure and possible overlap of ERP components of opposite polarity. Temporal principal component analysis (PCA) confirmed the separate influence of concurrent LPP and N400 ERP modulations, and the source of the largest factors was located using sLORETA. It is suggested that the increased N400 in response to trait inconsistencies reflects difficulties in understanding unanticipated behavior, while the LPP effect might reflect evaluative incongruence.
过去使用事件相关电位 (ERP) 进行自发性特质推断的研究一致报告，在社会期望违反后，晚期正电位 (LPP) 幅度增加，但 N400 调制没有变化。在本研究中，参与者阅读描述未知行为者行为的场景。它们包含了几个暗示积极特质的描述，然后是一个单独的最后一句话，描述与之前暗示的特质一致或不一致的行为。与之前的研究一样，我们在多个额部区域发现了不一致行为后 LPP 幅度显著增加。与之前的研究不同，我们还在几个中央顶叶区域发现了 N400 振幅增加。这些结果的差异可以从刺激呈现程序的微小差异和相反极性的 ERP 成分的可能重叠来解释。时间主成分分析 (PCA) 证实了并发 LPP 和 N400 ERP 调制的单独影响，并且使用 sLORETA 确定了最大因素的来源。这表明，对特质不一致的反应中 N400 的增加反映了理解意外行为的困难，而 LPP 效应可能反映了评估不一致。
