情绪词汇加工的事件相关电位的时空模式研究

Processing of emotional words under distinct awareness conditions： analysis of spatiotemporal pattern of event-related potential

目的通过事件相关电位（ERP）的时空模式探讨不同知觉条件下情绪词汇加工的神经机制．方法11名受试者从事情绪词汇加工后呈现的面孔照片组合的面孔性别判别任务。对不同知觉条件下情绪词与中性词的ERP差异波采用2（知觉：非觉察、觉察）×2（情绪词：正／中性、负／中性）重复测量方差分析，利用F值的统计参数映像呈现结果。结果F值统计参数映像显示：（1）显著交互效应（知觉×情绪）主要出现在左侧额颞区及右侧枕区（60～80ms）；（2）显著知觉效应主要出现在双侧额区和右颞区（110～150ms）；（3）显著情绪效应主要出现在左右半球的广泛区域（60～90ms）。结论ERP的时空模式提示了非觉察和觉察条件下情绪词汇加工早期激活同一神经网络，前者的激活强度较后者弱。

Objective To investigate the mechanism of neural processing of emotional words under distinct awareness conditions using spatiotemporal pattern of event-related potentials （ERP）. Methods The ERPs were recorded in 11 healthy subjects while they performed a task of perceptual judgement on facial photograph gender, which were arrayed behind emotional words. Word valence was an implicit processing factor. The 2 （consciousness： awareness, unawareness）×2 （positive/neutral, negative/neutral） factorial design of repeated-measure was applied to utilize the difference wave between emotional word under distinct awareness conditions. The analysis results were revealed by the statistical parametric mapping （SPM） of F value resulting from repeated measurement ANOVA. Results The SPM of F-value suggested significant interaction effect between awareness and word valence in left frontal-temporal areas and right occipital regions （60-80 ms）. The significant awareness effects occurred separately in bilateral frontal-partial and right temporal regions （110-150 ms）. The significant emotion effects occurred in left and right extensive cerebral hemisphere regions （60-90 ms）. Conclusion The spatiotemporal patterns of ERPs suggest the underlying mechanisms are that the emotional words processing of both unawareness and awareness might involve the same neural modules in earlier period. The former decreases the strength of those neural assemblies＇ activation than the latter. Either positive or negative words can activate left cerebral hemisphere simultaneously with right cerebral hemisphere.