儿童与成人对社会和非社会正性情绪刺激的脑电反应特征比较

Neurophysiological Correlations of Processing Socially and Non-Socially Pleasant Stimuli between Children and Adults

采用事件相关电位技术探究不同年龄群体社会与非社会正性情绪刺激加工是否具有差异。研究发现:在P2成分上,成人在情绪刺激下诱发的波幅大于儿童;N2成分上,儿童在三种情绪刺激条件下波幅无显著差异。成人在社会性情绪刺激条件下诱发的脑电波幅大于在中性情绪刺激条件和非社会情绪刺激条件下诱发波幅;在LPP早、中、晚时间窗中,儿童的LPP波幅大于成人。由此,儿童与成人在社会和非社会正性情绪刺激加工上存在明显差异,说明成人比儿童对社会性情绪刺激更加敏感且在情绪加工中耗费较少的认知资源。

Demands for social interaction are higher in late childhood as individuals experience growing independence.Age-related differences in the processing of socially and non-socially pleasant emotional stimuli may imply the process of individual socialization.For example,children may regulate,express,and even experience emotions differently in different stages of development.It reflects the priority of affective processing by turning from the self-oriented rewards to the complex social and interpersonal interactions.It is essential to individuals’psychological functioning which reflects the tendency of emotional responses to stimuli combined with the ability to modify these responses.Investigating age differences in the physiological components of emotional processing(e.g.,scalp-recorded event related potentials,ERPs)has significant importance in terms of understanding the emotional development.Examining age-related differences in the biomarkers for emotional processing has the potential to provide an important supplement to behavioral measures.In this study,we examined age-related differences in the event-related brain potential(ERP)modulations during processing of socially and non-socially pleasant stimuli.EEG was recorded from 19(M=20.7)adults and 17 children(M=10.12)by using the Picture Perception Paradigm.As the early components,the P2 was the prominent frontal component occurring just prior to N2 around 200 ms.It seemed to express arousal and emotive reaction to emotional stimulus.As another important early component relevant to emotional processing,the N2 was the largest negative deflection with a medial-frontocentral topography between 200–300 ms following stimulus onset.The N2 might be sensitive to the processing of emotional information.As a late component,late positive potential(LPP)was a typically sensitive biomarker of emotional processing.It reflected facilitated attention to emotional stimuli and the recruitment of prefrontal cortical resources associated with effective cognitive control.As the typical biomarkers of emotional processing,age-related differences in the early ERP components(e.g.,P2 and N2)and later ERP components(e.g.,LPP)were examined.Results showed that:(1)As the index of the visual perception in the early processing stage,the P2 was larger for socially pleasant pictures than neutral pictures.It was larger for adults than children.(2)As an index of the facilitated processing of motivationally salient stimuli,N2 was larger for children than adults.N2 was larger for socially pleasant pictures than non-socially pleasant pictures among adults.However,there was no significant difference among children.(3)As the index of emotion regulation in the late processing stage,the LPP was larger for children than adults in all time windows.In the later time window,the LPP was smaller for social than nonsocial pictures among children,but had no significant difference among adults.Age-related differences in P2 and N2 in the present study again demonstrated that developmental difference was deep-rooted in the early stage of perceptual and attentional processing.As same as the findings of early ERP components,the larger LPP among children suggested that children might have higher attentional processing and reactivity to emotional stimulus,and employed more cortical resources during later stage of emotional processing.These results indicated that socially pleasant emotions had a properly higher priority in effective processing during development.From late childhood to early adulthood,individuals underwent age-dependent changes in processing different pleasant stimuli.