Event-Related Potentials Of Emotion Processing In Children With Attention Deficit Hyperactivity Disorder And Its Relationship With Social Function

Attention Deficit Hyperactivity Disorder(ADHD)is a neurodevelopmental disorder characterized by attention-deficit,hyperactivity and impulsivity.As these typically characteristics,their social and academic functions suffer serious damages such as conflicting with adults frequently,non-accepted by peer groups,lack of friendships and so on.Emotion has significant adaptive values and it plays an important role in delivering information.We can know whether someone likes or dislikes what we are talking or behaving from their expressions or prosodies,so that we can have behavior adjustments to maintain good interpersonal relationships.The hyperactivity and impulsivity of ADHD children may be related to their deficits in emotion recognition.Previous research has suggested that ADHD adults have problems in recognizing emotions.However,the problems of whether ADHD children have the same problems as ADHD adults,recognition problems of which emotions are more obvious,whether emotion recognition abilities of different senses are similar and what's the relationship between emotion recognition abilities and social function are still unanswered,especially evidences from Event-related potential(ERP)studies are rare.Thus,with ERP technique,the present study explored the abilities of ADHD children in recognizing facial expressions and vocal prosodies.To investigate the time course of ADHD children in recognizing facial expressions and vocal prosodies,we recorded the electroencephalographic(EEG)data of 32 ADHD children collected from Shenzhen Child Health Hospital and 33 health children recruited from schools while they completed the Emotional Expression Task and Emotional Prosody Task.All participants were asked to react to certain type of expressions or prosodies as well as quickly.The correct answers of each emotion were calculated as their behavior index of emotion recognition abilities.Finally,behavioral data analysis and ERP analysis were conducted.Behavioral results indicated that:(1)The mean accuracy of all emotion faces was generally similar in healthy group while the accuracy of anger faces was significantly lower than that ofneutral in ADHD group.The mean accuracy of each group to vocal emotions was different between four emotions.The accuracy of ADHD group was significantly lower than that of healthy group in recognizing anger,fear and happy voices,but when participants recognized neutral voices,the accuracy of two groups was similar.(2)The mean reaction time of healthy group was significantly faster than that of ADHD group in all emotional faces and voices.At the same time,the mean reaction time of neutral voices was slower than anger and faster than happy voices in both groups.The ERP experiment showed the results that:(1)The P1 amplitude of anger faces were larger than that of fear,happy and neutral faces in healthy group.However,the P1 amplitude of all faces were similar in ADHD group.Compared to the healthy group,the ADHD group demonstrated smaller amplitude of P1 to anger faces.(2)The N170 amplitude of anger faces were larger than that of neutral faces in healthy group.However,the N170 amplitude of all faces were similar in ADHD group.Compared to the healthy group,the ADHD group demonstrated smaller amplitude of N170 to all emotions.(3)The P3 amplitude of all faces were similar in healthy group,but the P3 amplitude of anger and happy faces were smaller than that of neutral faces in ADHD group.The effect of group difference of P3 amplitude only existed in recognizing anger faces,healthy group showed greater amplitude than ADHD group.(4)Despite of group factor,anger and happy voices' N1 amplitudes were always smaller than neutral.The N1 amplitude of anger voices was smaller than that of fear,happy and neutral voices in healthy group,in contrast,the N1 amplitude of anger voices was greater than that of happy voices in ADHD group.The ADHD group showed smaller N1 amplitude to anger voices compared with healthy group.(5)The P2 amplitude of anger voices was smaller than that of fear,happy and neutral voices in healthy group.However,the P2 amplitude of anger voices was larger than that of fear voices in ADHD group.Compared to the healthy group,the ADHD group showed smaller P3 amplitudes to fear,happy and neutral voices.Referred to anger voices,the effect was reverse.(6)The P3 amplitude of anger and fear voices was greater than that of neutral voices in healthy group,but the P3 amplitudes of all emotional voices have no significant difference in ADHD group.The group difference of P3 amplitudes were significant in anger,fear and happy voices,healthy group showed greater amplitudes than ADHD group.Correlation results indicated that:(1)The score of WEIRS-P was significantly correlated with the accuracy of anger faces and P1 amplitude of anger faces.(2)The score of WEIRS-P was significantly correlated with both the accuracy of fear,happy voices and P2 amplitude of anger voices.Conclusion:(1)Emotional faces:(1)ADHD children have difficulties in recognizing visual social signals which symbolized punitive.(2)Children in healthy group show early attention bias to negative visual social signals,but it does not exist in ADHD children.(3)In the middle stage of emotion processing,ADHD children over encode all emotional expressions and the processing of anger faces is still attenuate compared with other emotions.(4)ADHD children are not sensitive to emotional visual social cues.ADHD children process the negative and positive emotional visual stimuli more rougher and superficial than healthy children in the final stage.(2)Emotional voices :(1)ADHD children have difficulties in recognizing both punitive and rewarding auditory social signals.(2)Children in healthy group show early attention bias to negative auditory social signals,but it does not exist in ADHD children.(3)In the middle stage of emotion processing,ADHD children over integrate the acoustic clues of anger voices while the integration of fear,happy and neutral voices' s acoustic clues is insufficient.(4)ADHD children are not sensitive to emotional acoustic social clues.ADHD children process the negative and positive emotional acoustic stimuli more rougher and superficial than healthy children in the final stage.(5)Anger and happy voices can attract more attention in the early stage.(3)In terms of different emotions,ADHD children's abilities to recognize anger emotion are more stronger related to their social functions;for different senses,ADHD children's acoustic emotion recognition abilities are more closer related to their social functions.