具有两个叉的三叉戟不可能图形加工的电生理基础:一项ERP的研究

Electrophysiological Correlates of Visual Illusion Effect in the Two-Pronged Trident: An Event-Related Potential Study

采用事件相关电位技术(ERP),探讨了具有两个叉的三叉戟不可能图形加工的脑内时程动态变化,结果表明:首先在250～310ms事件窗口内,与PC(不可能条件,Possible Condition)相比,IC(可能条件,Impossible Condition)诱发了一个更正的波形(P250～310),对差异波(IC—PC)进行偶极子溯源分析,结果显示,P250～310可能起源于海马旁回.因此,P250～310可能与知觉加工过程中,将物体的各个分散特征,整合成空间上相关的物体表征的过程有关;其次,在400～500ms时间窗口内,IC比PC诱发了一个更负的波形,对差异波(IC—PC)进行偶极子溯源分析,结果显示,N400～500可能起源于扣带前回(anterior cingulate cortex,ACC)和右侧颞叶(temporallobe),因此,N400～500可能与认知冲突(不可能图形中所包含的空间结构与个体三维知识经验相违背)的监测与控制有关;最后,在500～600ms时间窗口内,IC比PC诱发了一个更正的波形(P500～600),此波形可能与工作记忆中对不可能图形的空间结构的推测有关(通过空间结构推理,进而发现不可能图形的空间结构在现实生活中无法存在).

Event-related brain potentials（ERPs） were used to examine the electrophysiological correlates of a visual illusion effect in the two-pronged trident figure.Scalp ERP analysis revealed that Impossible condition elicited a more positive ERP deflection（P250~310） than did possible condition over the anterior scalp regions between 250-310 ms.Dipole source analysis of the difference waves（Impossible minus Possible condition） localized the generator of the P250~310 in the right parahippocampal gyrus,which might be related to integration of image fragments into spatially coherent object representations in the stage of perceptual processing.Then,Impossible condition elicited a more negative ERP deflection（N400~500） than did Possible condition in the right hemisphere between 400~500 ms.Dipole source analysis of the difference waves localized the generators of the N400~500 in the anterior cingulate cortex（ACC） and the right temporal lobe,which might be involved in monitoring and controlling cognitive conflict（spatially impossible coherent structure violated the individual 3-D knowledge）.Last,Impossible condition elicited a more late positive potential component（LPC） than did Possible condition over the anterior scalp regions between 500~600 ms,which might reflect judgment validation and making a decision in working memory.