The Influences Of Social Exclusion On Cognitive Control And The Underlying Psychological Mechanisms

As social creatures,people have a fundamental need to feel socially accepted and maintain strong,stable social bonds with others.The satisfaction of this fundamental need is important for our social life and physical(mental)health.However,this need to belong is often challenged by social exclusion,an aversive but prevalent phenomenon in daily life.Given the prevalence of social exclusion in our daily life,it has been a hot topic to examine the impact of social exclusion on human life.Currently,the existing studies have mainly focused on the influences of social exclusion on an individual's social function,and few studies have explored the cognitive mechanisms behind this influence.Therefore,using three EEG studies,our current study aims to examine the impact of social exclusion on cognitive control and the underlying psychological mechanisms.In general,building on previous studies,the current study primarily focuses on two issues: issue 1,whether and how social exclusion influences cognitive control(i.e.,impairs,improves,or exerts no influence),and issue 2,determining the underlying mechanisms of this influence(e.g.,impaired performance caused by exclusion is due to the inability to exert control,unwillingness to exert control,or both).To explore the above issues,we adopted the Cyberball game to manipulate social exclusion,and then asked the participants to perform the cognitive control tasks and simultaneously record the EEG activities.Specifically,in Study 1 and Study 2,we first examined how social exclusion influences inhibitory control and working memory,respectively,and we observed both improvement and impairment effects of social exclusion on cognitive control.We thought these inconsistent results might be caused by the fact that in these two studies,we treated cognitive control as a unitary concept,while the recent proposed Dual Mechanisms of Control(DMC)framework points out that cognitive control can be divided into proactive control and reactive control.Therefore,in Study 3,in order to reconcile above inconsistent results,we examined how social exclusion influences proactive and reactive control under the DMC framework;furthermore,we also examined the underlying mechanisms of social exclusion's modulation on proactive and reactive control.In Study 1,through two experiments,we examined the effects of social exclusion on behavioral inhibition and interference control,respectively.Specifically,in Experiment 1,through adopting the masked Go/No-Go task,we examined how social exclusion influences conscious and unconscious behavioral inhibition.Results suggested that social exclusion exerted different effects on conscious and unconscious behavioral inhibition.For conscious behavioral inhibition,excluded individuals showed a larger N2 but smaller P3 effects than included individuals,suggesting that excluded people invest more attention in conscious conflict detection,but less in conscious inhibition of impulsive responses.However,for unconscious behavioral inhibition,excluded individuals showed a smaller N2 but larger P3 effects than included individuals,suggesting that excluded people invest less attention in unconscious conflict detection,but more in unconscious inhibition of impulsive responses.These results suggest that social exclusion doesn't simply exert a hindrance effect on behavioral inhibition;instead,it causes people to adopt a more flexible and adaptive strategy for attention allocation in behavioral inhibition: excluded individuals prioritize the detection of obvious threats so as to make a quick response,whereas less obvious threats are disregarded and priority is given to inhibitory control.In Experiment 2,through adopting the additional singleton paradigm and manipulating the relative position of the distractor and the target stimulus(target and salient distractor were either both presented laterally or one was presented on the vertical midline and the other laterally),we examined whether social exclusion impairs selective attention(i.e.,interference control),and specifically examined its effect on two hypothesized mechanisms of selective attention: target enhancement and distractor suppression.Results showed that social exclusion differentially affected target and distractor processing.While exclusion impaired distractor suppression,reflected as smaller distractor-positivity(Pd)amplitudes for the exclusion group compared to the inclusion group,it did not affect target enhancement,reflected as similar target-negativity(Nt)amplitudes for both the exclusion and inclusion groups.In Study 2,through two experiments,we examined the effects of social exclusion on attentional filtering ability and storage capacity of visual working memory,respectively.Specifically,in Experiment 3,through adopting the lateralized change detection task with distractors(participants were made to remember the orientations of red rectangles while ignoring salient green rectangles),we mainly examined how social exclusion influences attentional filtering ability.Results showed that social exclusion exerted a general impairment effect on attentional filtering ability,as excluded individuals exhibited weaker filtering ability than included individuals under both easier filtering condition(i.e.filter out only one distractor)and harder filtering condition(i.e.filter out two distractors).This was reflected by the similar contralateral delay activity(CDA)amplitudes for onetarget-one-distractor condition and two-targets condition,as well as the similar CDA amplitudes for two-targets-two-distractors condition and four-targets condition in excluded individuals.These results suggest that social exclusion impairs the ability to filter out irrelevant items from visual working memory.In Experiment 4,through adopting the lateralized change detection task without distractor(participants were asked to remember 1–5 colored squares),we further examined how social exclusion influences storage capacity.Results showed that social exclusion reduced storage capacity,as the CDA amplitudes reached asymptote at loads of two items for excluded individuals and at loads of three items for included individuals.In Study 3,through two experiments,we examined how social exclusion modulates proactive and reactive control,and the underlying mechanisms driving this modulation,respectively.Specifically,in Experiment 5,through adopting the classical AX-CPT task,we examined the modulation effect of social exclusion on proactive and reactive control.Results showed that social exclusion weakened proactive control but enhanced reactive control,as reflected by the smaller proactive control index of accuracy at the behavioral level;and the weaker proactive control indicators(i.e.,P3 b and CNV amplitudes),but strengthened reactive control indicators(N2 amplitudes)at the neural level,for excluded individuals than for included individuals.In Experiment 6,through designing and adopting the Cued-flanker task(we manipulated the possibility and advantage to engage proactive control by varying in whether task cues were available before or after target onset),we further examined the underlying mechanisms of the weakened proactive control(inability hypothesis vs.unwillingness hypothesis).Results showed that excluded individuals would not engage proactive control when the advantage of proactive control was not salient,supporting the unwillingness hypothesis.However,when the advantage of proactive control was particularly salient and at a high level,excluded individuals did engage proactive control,but their ability to exert proactive control was still weaker than included individuals,supporting the inability hypothesis.These results suggest that the weakened proactive control caused by social exclusion is due to both impaired ability and lower motivation.In summary,through these three EEG studies,our current study systematically examined the effects of social exclusion on cognitive control and the underlying psychological mechanism.Based on the results of these studies,we could draw two important conclusions.First,social exclusion exerts complex effects on cognitive,as improvement,impairment,and none influence effects could all appear.One possible solution to reconcile these inconsistent and complex results is to examine this issue under the DMC framework.Indeed,we found that social exclusion would modulate the tradeoff between proactive and reactive control,contributing to a preference for reactive control over proactive control.Since there are only a few studies exploring the relationship between social exclusion and cognitive control,these results could fill this gap to some extent,and provide some reference for future research.Second,both impaired ability and lower motivation lead to weakened proactive control after experiencing social exclusion.Since the controversies regarding the psychological mechanism underlying social exclusion's modulation on cognitive control still exist,our current results are important for us to understand the negative influences of social exclusion,and these results also indicate promising implications for designing effective interventions to alleviate the negative consequences of social exclusion.In a word,our current studies enrich and extend the existing research,deepen our understanding of the relationship between social exclusion and individual social function,and to some extent validate and improve existing theories of social exclusion.