The Neurophysiological Mechanisms Underlying Gender Effect On Processing Of Social Exclusion

Social exclusion,as a common social phenomenon,has an impact on perception,emotion,behavior,and even health.How people process social exclusion has become a major research hotspot.Although existing behavioral and physiological studies have reported the gender effect on the processing of social exclusion,little is known about its cognitive neural mechanisms.Research on emotion and physiological research on social exclusion revealed significant gender differences in emotional arousal,cognitive control and emotional inhibition,the present study tried to investigate the gender effect on the processing of social exclusion from the neural and physiological point of view,specifically,to investigate whether females will have a stronger emotional arousal in social exclusion,and males will show more cognitive emotional control,we also want to test the internal consistency of neural and physiological results.The present study employed the chat room paradigm to elicit social exclusion.In the first experiment,we used event-related potential technique to investigate gender differences in the time course of neural mechanisms underlying social exclusion.In the second experiment,we used eye-tracking technique to explore the gender differences in eye movement.Then,by synthesizing the results of the two experiments,we demonstrated the gender differences in neurophysiological mechanisms of social exclusion.We found that:(a)Behavior results:Females were more unpleasant than males when being excluded.In contrast,females were more pleasant than males when being included.(b)ERP results:Social exclusion in relative to social inclusion elicited greater right occipital temporal P100 for both females and males.Compared to social inclusion,social exclusion elicited more negative left frontal-central N100 and earlier P100 for females rather than for males.Compared to social exclusion,social inclusion elicited greater left parietal P3b(300-480 ms)for females rather than for males.Compared to males,females had more positive LPP(500-800ms)for both social exclusion and inclusion,whereas,the left parietal LPP retains the P3b pattern,with more positive amplitudes for females when being included,but not for males.For the LNCl(450-750 ms),males had more negative amplitude than females for both social exclusion and inclusion.For the LNC2(750-1000 ms),compared to social inclusion,social exclusion elicited more negative amplitudes at the right frontal area.(c)Eye-tracking results:For the fixation frequency,social inclusion led to more eye fixations on participants' own photographs,in contrast,social exclusion resulted in more eye fixations on the photograph of the evaluator.For the pupil size,the pupil was significantly dilated more when females were excluded as compared to when they were included,but such effect did not obtained in males.The ERP results suggested that in the early stage of neural activity in social exclusion,social exclusion as a type of emotional event,elicited participants' greater bottom-up arousal,which indexed by the P100 in the right occipital temporal area and the N100 in the left frontal-central area,and female's awareness was more rapid.In the mid-term stage of neural activity in social exclusion,females had more attentional allocation and make event categorization assigned to positive feedback(i.e.,social inclusion),indexed by the left parietal P3b and the LPP in the left central-parietal area,whereas males did not show such difference.In the late stage of neural activity in social exclusion,compared to females,males exhibited more cognitive control and emotional inhibition of both social exclusion and inclusion,indexed by LNC1.However,such gender differences did not observed in the later ERP component(i.e.,LNC2),which indicated inhibition of negative emotion elicited by social exclusion.The eye-tracking results revealed the physiological mechanisms underlying social exclusion.Firstly,social exclusion vs.social inclusion effect in fixation frequency reflected individuals' tendency to rebuild social connections leading to more prosocial behavior.Gender differences in pupil size reflected that only females had stronger emotional arousal when being excluded.In sum,the ERP and eye-tracking results consistently revealed that females have stronger automatic emotional arousal to social exclusion,while males show stronger cognitive control and emotional inhibition.Such gender effect is also demonstrated in previous studies on emotion processing,reflecting the inherent consistency of gender differences in social emotional processing.