卡通表情自动加工的失匹配负波研究

目的 采用事件相关电位(Event-related potential,ERP)技术探讨人脑对卡通表情自动加工的脑电生理机制.方法 受试者为16名健康人(男7,女9).要求受试者观看卡通表情图片并计数靶刺激绿色图片的呈现次数,而忽略非靶刺激红色图片(包括作为标准刺激的中性表情及作为偏差刺激的情绪性表情).记录32导脑电,对受试者的视觉失匹配负波(Mismatch negativity,MMN)的波幅进行分析.结果 (1)MMN1:波幅分另为(-0.570±0.076)μV(TP7/TP8)、(-0.840±0.119)μV(A1/A2)、(-1.199±0.105)μV(T5/T6)、(-1.184±0.102)μV(O1/O2).波幅的电极位置主效应显著(F(3,45)=8.340,P＜0.05).方向与半球存在交互效应显著(F(1,15)=11.977,P＜0.05).(2)MMN2:波幅分别为(-0.469±0.126)μV(TP7/TP8)、(-1.014±0.255)μV(A1/A2)、(-1.071±0.182)μV(T5/T6)、(-0.915±0.178)μV(O1/O2).方向主效应差异有显著性(F(1,15)=7.232,P＜0.05),且方向与表情交互效应显著(F(1,15)=6.458,P＜0.05),方向与半球交互效应显著(F(1,15)=11.907,P＜0.05).结论 人脑对正、负性卡通表情均可进行自动加工,而负性表情自动加工较正性表情更强;表情信息自动加工存在右侧偏侧化效应.

Mechanism of automatic processing of cartoon facial expressions:a mismatch negativity study

Objective To investigate the mechanism of automatic processing of cartoon facial expressions by using event-related potential(ERP).Methods Sixteen healthy volunteers (7 males and 9 females) were recruited for this study.The subjects were instructed to mentally count green faces (targets) and ignore the red ones (non-targets) including standard neutral expressions and deviant emotional expressions.Thirty two channels electroencephalogram (EEG) was recorded by Neuroscan Nuamps System.The amplitudes of mismatch negativity (MMN) were analyzed.Results (1) MMN1:the amplitudes were(-0.570 ± 0.076) μV (TP7/TP8),(-0.840 ±0.119) μV(A1/A2) ,(-1.199 ±0.105)μV(T5/T6) ,(-1.184 ±0.102)μV(O1/O2).There was a significant main effect of site (F(3,45) = 8.340, P ＜ 0.05 ) and an interaction of orientation × hemisphere (F(1,15) =11.977, P＜0.05).( 2 ) MMN2: the amplitudes were (-0.469 ± 0.126 ) μV ( TP7/TP8 ), (-1.014 ± 0.255 ) μV(A1/A2) ,(-1.071 ±0.182)μV(T5/T6), (-0.915 ±0.178)μV (O1/O2).There was a significant main effect of orientation (F(1,15) = 7.232, P ＜ 0.05 ) and interactions of orientation × type (F(1,15) = 6.458, P ＜ 0.05 )and orientation × hemisphere(F(1,15) = 11.907, P＜0.05 ).Conclusion Cartoon emotional faces elicit expressionrelated MMN indexing automatic processing.The MMN amplitude is right-lateralized and larger for negative than positive expression.