The Role Of Cognitive Control In Selective Attention To Emotional Stimuli In Individuals With Subclinical Anxiety And Depression

Objective:To study the effect of cognitive control on selective attention to emotional stimuli in subjects with subclinical anxiety and depression.Methods:Flanker task was used as a paradigm in the two studies in this paper.Each study included a behavioral experiment and an event-related potential experiment.In study 1,to investigate the effect of working memory load on selective attention in the subclinical anxiety individual,two(happy vs.angry)and three emotional faces(angry,happy or calm faces)were used respectively as targets and distractors.Whereas in Experiment 2,to investigate the effect of working memory load on selective attention in the subclinical depression individual,two(happy vs.sad)and three emotional faces(sad,happy or calm faces)were used respectively as targets and distractors.Results:(1)The behavioral results of study 1 found no group and target expression effects.There was no significant main effect and interaction in accuracy.But response time turns out that all subjects under high working memory load responsed significantly slower than under low working memory load;Main effect of distractior expression shows that when angry distractors were present,the response time was significantly longer than when happy distractors and calm distractors were present.The ERP results of study 1 did not found any main effect neither,but the 3-way interaction(group×target expression × distractor expression)shows that when calm distractiors appeared,the average N2 amplitude of happy targets was significantly higher than that of angry targets in control group.In addition,when faced with angry distractiors,the anxious subjects produced a larger average N2 amplitude when angry targets were present than happy targets were present,while the control group produced a larger amplitude in the face of happy targets than in the face of angry targets.In addition,the 2-way interaction of group × target expression was found,the control group produced a larger N2 amplitude when confronted with happy targets than angry targets.(2)The behavioral results of study 2 found no main effects for groups and targets expression,but acuracy was significantly lower under high working memory load than under low working memor load for all of the subjects;Main effect for distractor expression shows when sad distractors were presented,accuracy was significantly higher than happy distractors and calm distractors were presented.2-way interaction(working memory load × distractor expression)showed that this difference only occurred under high working memory load.In addition,response time was significantly longer when all subjects were under high working memory load than than under low working memory load.The ERP results of study 2 did not found any main effect of group/working memory load/distractor expression,but the group×working memory load×distractor expression interaction was significant: Regardless of the expression of target,mean amplitude of N2 in the depressed individuals was significantly higher than that in the control group under low working memory load at all of the distractors.But under high working memory load,there was no significant difference between the two groups in the interference with sad distractiors,and the depressed group only showed a higher N2 amplitude in the presence of happy and calm distractiors.Further more,interaction between target expression and working memory load shows the average amplitude of N2 produced by happy targets was significantly higher than that of sad targets under high working memory load.Conclusion:(1)When performing an emotional selective attention task with emotional distractors,cognitive control could affect the behavioral response of subjects,but at the initial stage of attention,the regulatory ability of cognitive control was limited by the type of participants and the expression of the targets and distractors.(2)Anxious subjects performed a stronger bias towards the angry faces than healthy controls,and this performance was not affected by working memory load.(3)The bias of depressed individual towards sad faces was influenced by working memory load,it becomes weaker when working memory load was high.In addition,depressed individual was distracted stronger no matter what kind of working memory load was exerted.