Electrophysiological Mechanism Of Attentional Bias Toward Negative Information In PTSD Adolescents After Earthquake

Researches have provided evidence regarding attentional biases?for trauma-related information in PTSD teenagers,but the specific neural mechanism has not come to an unanimous conclusion.The present study leveraged event-related potentials(ERPs)in conjunction with behavioral measures in the dot-probe task to examine precise neural mechanisms underlying attentional processing of negative information in 30 earthquake PTSD teenagers and 30 non-PTSD teenagers.Experiment 1 explored neural mechanisms underlying attentional processing of trauma-related words in earthquake PTSD teenagers,using a 2(emotion words:earthquake-related,positive)×2(cue congruence:congruent,incongruent)×2(group:PTSD,non-PTSD)three factors mixed design.The behavioral results showed evidence of attentional bias for both emotion words in PTSD teenagers as indexed by facilitated response time for congruent trials than incongruent ones.As for accuracy,both groups performed poorly for earthquake-related words than positive words,and PTSD teenagers have poorer performance than non-PTSD teenagers.In posterior scalp region,PTSD teenagers showed enhanced P1 component than non-PTSD group.Experiment 2 explored neural mechanisms underlying attentional processing of trauma-related pictures in earthquake PTSD teenagers,using earthquake-related and positivepictures as materials.The behavioral results showed evidence of attentional bias for earthquake-related pictures in PTSD group,as indexed by facilitated response time for congruent trials than incongruent ones,while non-PTSD teenagers showed attentional disengagement from earthquake-related pictures and positive pictures,as indexed by facilitated response time for incongruent trials than congruent ones;additionally,as for accuracy,PTSD teenagers have poorer performance than non-PTSD teenagers.In posterior scalp region,ERPs revealed hyper-vigilance for earthquake-related pictures in both groups,reflected by enhanced P1 component toward earthquake-related pictures comparing to neutral pictures,as well as increased P2?P3 and LPP component towards earthquake-related pictures comparing to neutral pictures in PTSD group.While non-PTSD group showed increased P2 and P3 component towards positive pictures comparing to neutral pictures.Experiment 3 explored neural mechanisms underlying attentional processing of trauma-related pictures of different valence in earthquake PTSD teenagers,using high and low valenceearthquake-relatedpictures as materials.The behavioral results showed evidence of attentional bias for earthquake-related pictures of two valence,while non-PTSD teenagers showed attentional disengagement from earthquake-relatedpictures of both valence.In posterior scalp region,ERPs revealed increased P1 for both earthquake-related pictures in two groupscomparing to neutral pictures,as well as increased P2 component towards high valence earthquake-related pictures comparing to low valence earthquake-related pictures and increased P2 component towards low valence earthquake-related pictures comparing to neutral pictures.While PTSD teenagers showed increasedP3 and LPP component towards both earthquake-related pictures comparing to neutral pictures.Experiment 4 explored neural mechanisms underlying attentional processing of trauma-related pictures and generally negative pictures in earthquake PTSD teenagers,using earthquake-related and generally negativepictures as materials.The behavioral results showed evidence of attentional bias for earthquake-related pictures in earthquake PTSD,not for generally negative pictures.While non-PTSD teenagers showed attentional disengagement from both picitures.In posterior scalp region,ERPs revealed hyper-vigilance for earthquake-related and generally negative pictures in both groups,reflected by enhanced P1 component toward earthquake-related and generally negative pictures comparing to neutral pictures,as well as increased P2 component towards generally negative pictures comparing to earthquake-related and neutral pictures,and increased P2 component towards earthquake-related pictures comparing to neutral pictures.PTSD group showed greatest P3 and LPP amplitude for earthquake-related pictures.While non-PTSD group,showed greater P3 amplitude for generally negative pictures andearthquake-related picturescomparing to neutral pictures.According to the results of above experiments,it was concluded that:(1)Earthquake PTSD teenagers do show significantly "attentional vigilance?difficulty in disengagement" effect for both emotion words,not only for trauma-related words.(2)Earthquake PTSD teenagers do show significantly "attentional vigilance-difficulty in disengagement" effect for earthquake-related pictures,while non-PTSD teenagers show significantly "attentional vigilance-attentional disengagement"effect for earthquake-related pictures.(3)Earthquake PTSD teenagers do show significantly "attentional vigilance-difficulty in disengagement" effect for both earthquake-related pictures,while non-PTSD teenagers show significantly "attentional vigilance-attentional disengagement" effect for both earthquake-related pictures.(4)Earthquake PTSD teenagers do show significantly "attentional vigilance-difficulty in disengagement" effect for earthquake-related pictures and "attentional vigilance-attentional disengagement" effect for generally negative pictures,while non-PTSD teenagers show significantly "attentional vigilance-attentional disengagement" effect for both pictures.