Behavioural and ERP evidence of a contrary effect between active and passive suppression of facial expressions

There has been disagreement regarding the relationship among the three components (subjective experience, external performance, and physiological response) of emotional responses. To investigate this issue further, this study compared the effects of active and passive suppression of facial expressions on subjective experiences and event-related potentials (ERPs) through two experiments. The two methods of expression suppression produced opposite patterns of ERPs for negative emotional stimuli: compared with the free-viewing condition, active suppression of expression decreased, while passive suppression increased the amplitude of the late positive potential (LPP) when viewing negative emotional stimuli. Further, while active suppression had no effect on participants' emotional experience, passive suppression enhanced their emotional experience. Among the three components of emotional responses, facial expressions are more closely related to the physiological response of the brain than to subjective experience, and whether the suppression was initiated by participants determines the decrease or increase in physiological response of the brain (i.e. LPP). The findings revealed the important role of individual subjective initiative in modulating the relationship among the components of emotional response, which provides new insights into effectively emotional regulation.