Effects Of High-definition Transcranial Direct Current Stimulation On Social Avoidance In High Autism Traits Individuals

Objective:Social avoidance is a core characteristic for high autistic traits individuals in social interaction,and impaired social function has brought trouble to the social life of high autistic traits individuals.However,there are few studies on social avoidance intervention for high autistic traits individuals.This study aimed to examine the effect of high-definition transcranial direct current stimulation(HD-t DCS),for five consecutive days,over the dorsolateral prefrontal cortex(DLPFC)on social avoidance with high autistic traits individuals using eye-tracking technology.Method: we collected the Autism Spectrum Quotient Questionnaire(AQ)in Anhui Medical University.A total of 560 questionnaires were collected and individuals who scored in the top 10% were invited to continue participating in our experiment(AQ score ≥ 128).In the end,36 participants completed the entire experiment,including 18 true stimuli and 18 false stimuli.After that,HD-t DCS intervention was conducted twice a day,with a stimulation time of 20 minutes each time,and the time interval between the two interventions was at least greater than 4 hours.The intervention lasted for five consecutive days.Before and after intervention,subjects were required to complete a series of neurometric questionnaires and two eye-movement paradigms(the social gaze paradigm and social interaction paradigm).Results: Experiment 1: In the social gaze paradigm,after the intervention,the fixation time at averted gaze in the area of the eyes in the true stimulation group significantly increased(t=-2.48 P=0.024),but there was no significant change in the fixation time for direct gaze(t=-0.23 P=0.821).There was no significant difference in fixation time in eyes in the sham stimulation group at post-intervention(F=0.047,P=0.832).There was no significant difference in fixation time for direct gaze(t=-0.297 P=0.769)and averted gaze(t=1.408 P=0.168)between the true and false stimulation groups after intervention.In the area of the mouth,there was no significant difference(F=0.619,P=0.437).Experiment 2: In the social interaction paradigm,after intervention,the fixation time(t=-3.454 P=0.003),fixation count(t=-2.56 P=0.02),and glance duration(t=-4.057P=0.001)for social stimuli in the picture in the true stimulation group significantly increased,while the fixation count(t=2.295 P=0.035),and glance duration(t=-6.034P=0.00)for non-social stimuli significantly decreased in the true stimulation group.However,there was no significant difference in fixation time(F=0.007 P=0.935),fixation count(F=0.233 P=0.636),and glance duration(F=0.002 P=0.966)before and after intervention in the sham stimulation group.After the intervention,there were no significant differences in fixation time(t=0.603 P=0.55,t=-1.804 P=0.083),fixation count(t=1.546 P=0.132,t=-0.923 P=0.363),and glance duration(t=1.441 P=0.159,t=-1.9 P=0.068)for social and non-social stimuli in the true and false stimulation groups.Conclusion: This proves that the intervention of HD-t DCS over DLPFC on high autistic traits individuals can promote information processing in the eye region and promote the fixation time for the averted gaze;Promoting attention to social stimuli in social scene.It provides a reference for future intervention research on social avoidance in high autistic traits groups,but further research and exploration are still needed.