Study On The Behavior And Electrophysiology Of ADHD Phenotypes In Sustained Attention Tasks

Attention Deficit Hyperactivity Disorder(ADHD)is a common neurodevelopmental disorder in children and adolescents.ADHD includes inattentive type of ADHD.ADHD-I,hyperactive/impulsive type of ADHD(ADHD-HI),and combined type of ADHD(ADHD-C).Sustained attention reflects the stability of attention.In previous studies,ADHD children’s sustained attention has obvious defects,and it is usually measured by the mean value and standard deviation of individual reaction time,which mainly reflect the overall fluctuation of sustained attention.It is worth noting that in recent years,many research results suggest that the fluctuation of sustained attention may be periodic,so the low frequency amplitude of response time has been widely concerned by researchers as a new measurement index of sustained attention.Despite numerous studies,the differences in these behavioral indicators between phenotypes and the neurophysiological mechanisms underlying these differences remain unclear.Two experiments were carried out around the above problems.Experiment I examined the differences between phenotypes on behavioral indicators of sustained attention tasks.101 children with ADHD participated in the experiment.The study first evaluated the traditional indexes of the variation of reaction time within the subjects,namely the mean value of reaction time and the standard deviation of reaction time,and then calculated the low frequency amplitude of reaction time in three frequency bands,namely 0.01-0.027 Hz,0.027-0.073 Hz and 0.073-0.167 Hz.Finally,analysis of variance was used to verify the differences between attention deficit type and mixed type in these indicators.This study explores the differences in behavioral indicators between the attention deficit type and the mixed type.In experiment 2,the EEG method was used to explore the differences in electroencephalogram(EEG)activity between children with attention deficit and mixed ADHD during continuous tasks.73 children with ADHD participated in this EEG experiment.In this study,The average power spectrum of quantitative EEG(Delta: 1-4Hz,Theta: 4-8Hz,Alpha: 8-14 Hz,Beta: 14-30 Hz,and Gamma: 30-50Hz)was calculated,and the correlation between EEG parameters and the scale scores was further explored.The results showed that the behavioral indicators of ADHD children were significantly different among different phenotypes.Among them,there was no significant difference between ADHD-C and ADHD-I in RT-Mean,but there was significant difference in RT-SD,and the RT-SD of ADHD-C was significantly higher than that of ADHD-I.At the same time,the RT-ALFF of ADHD-C was significantly higher than that of ADHD-I in the 0.01-0.027 Hz band.In the 0.027-0.073 Hz band,there was no significant difference in RT-ALFF between ADHD-C and ADHD-I.In the0.073-0.167 Hz band,the RT-ALFF of ADHD-C was significantly higher than that of ADHD-I.In addition,EEG experiment results showed that EEG rhythm waves were different between ADHD-I and ADHD-D.Specifically,on the F3 electrode,Theta wave in children with ADHD-C was significantly higher than that in children with ADHD-I(t=-2.203,p=0.030).Beta wave in children with ADHD-I was significantly higher than that in children with ADHD-C(t=2.175,p=0.032).At the Fz electrode,the Theta wave of children with ADHD-C was significantly higher than that of children with ADHD-I(t=-2.409,p=0.018),and the Alpha wave of children with ADHD-I was significantly higher than that of children with ADHD-C(t=2.053,p=0.043).At the C3 electrode,the Delta wave(t=-2.053,p=0.043)and Beta wave(t=-2.403,p=0.034)of children with ADHD-C were significantly higher than those of children with ADHD-I.At the C4 electrode,the Alpha wave of children with ADHD-I was significantly higher than that of children with ADHD-C(t=2.148,p=0.035).At the Cz electrode,the Delta wave of ADHD-C children was significantly higher than that of ADHD-I children(t=-2.264,p=0.026).At P3 electrode,Alpha wave was significantly higher in children with ADHD-C than in children with ADHD-I(t=-2.061,p=0.042).Other difference tests were not significant.This paper provides a basis for the difference of the indicators of sustained attention behavior in different phenotypes and provides a methodological basis for future research.We further explored the brain mechanism of different phenotypes,and these findings provide methodological implications for the future clinical diagnosis and treatment of children with attention deficit hyperactivity disorder.