An ERP Study On Sound Localization And Auditory Selective Attention In School-Aged Children With ADHD

In complex sound environments,it is important to identify,locate,and selectively pay attention to the sounds of interest.But as so far there is a lack of convincing evidence whether this ability,auditory spatial selective attention,is impaired in children with Attention-Deficit/Hyperactivity Disorder（ADHD）.Thus,the present study aimed to investigated the neurophysiological basis of auditory selective attention deficits in children with ADHD,in addition to exploring the classical MMN and P300 components that can be evoked by the Oddball paradigm,the focus was on exploring the ERP components related to auditory spatial localization and selective attention:Ta,N2ac（N2-anterior-contralateral）,LPCP（Late Posterior Contralateral Positivity）.Part 1:Objective:To explore whether"adult-like"auditory spatial selective attention components can be induced in children and whether children with ADHD have dysfunctional auditory spatial selective attention.Method:EEG data were collected from 7-to 11-year-old children with ADHD（n=54）and age-,sex-,and IQ-matched typically developing（TD）children（n=61）,while they performed an auditory search task based on Oddball paradigm.Results:1.For behavior,the children with ADHD showed a shorter correct reaction time（RT;t=-2.060,p=0.042）but a higher RT coefficient of variability(RT_CV;t=2.332,p=0.021)than TD children,and marginal more error numbers（ERROR;t=1.902,p=0.060）.2.For the classical ERP components of the Oddball paradigm,MMN and P300,the differences were not significant between the two groups.Moreover,the differences between the MMN components induced by target deviants and non-target deviants were not significant.But the P300 induced by target deviant stimuli was significantly larger than that of non-target deviant stimuli（ps<0.029）.3.For the ERP components about auditory spatial selective attention:（1）For the lateralization effect,unilaterally presented sound stimuli,both target and non-target,showed significant lateralization effects in both groups of children in the early（Ta,50-150 ms）,middle（N2ac,200-350 ms）,and late（LPCP,400-600 ms）periods after stimulus presentation（ps<0.001）.In the early period,target Ta was smaller in children with ADHD than TD（t=-2.312,p=0.023）,whereas non-target Ta was larger than TD（t=2.580,p=0.011）.In the middle period,target N2ac was comparable between the two groups（t=0.279,p=0.781）.In contrast,non-target N2ac was significantly larger in the ADHD group than TD（t=-2.899,p=0.005）.In the late period,target LPCP was comparable between the two groups（t=0.349,p=0.728）,while non-target LPCP was significantly larger in children with ADHD than TD（t=2.642,p=0.009）.（2）For the selective effect,TD children showed significantly more target lateralization than non-target lateralization in all three periods（ps<0.001）.In contrast,no selective effect was observed in children with ADHD due to similar target and non-target lateralization effects in all periods（ps>0.077）.（3）Group×Condition×Period ANOVA showed a significant interaction effect(F_2,112=4.786,p=0.010,²=0.079).TD children showed consistent target lateralization greater than non-target lateralization across the three periods（ps<0.006）.Whereas in the Ta period,children with ADHD showed the non-target lateralization effect was significantly larger than the target（p=0.036）;in the N2ac period,the non-target lateralization effect was similar to the target（p=0.115）;while in the LPCP period,the target lateralization effect was marginally larger than the non-target（p=0.084）.4.The correlation results of behavioral data,symptom severity and EEG data（with age and sex controlled）:（1）In the ADHD group,the larger target MMN was significantly correlated with smaller RT_CV（r=0.378,p=0.006）and less ERROR（r=0.278,p=0.046）;the larger target P300 was correlated with slower RT（r=0.388,p=0.004）,while larger non-target P300was correlated with smaller RT（r=-0.297,p=0.033）.The lack of N2ac selective effect was correlated with faster RT（r=0.287,p=0.039）.The larger target LPCP lateralization effect was correlated with faster RT（r=-0.293,p=0.035）.（2）In the TD group,the smaller non-target MMN was correlated with shower RT（r=0.284,p=0.030）.Also,the smaller non-target P300 was correlated with shower RT（r=-0.268,p=0.040）but smaller RT_CV（r=0.358,p=0.005）.The larger target and non-target N2ac lateralization effects were significantly correlated with faster RT（target:r=0.296,p=0.023;non-target:r=0.303,p=0.020）.Moreover,larger target LPCP lateralization effect was correlated with smaller ERROR（r=-0.292,p=0.025）,larger non-target LPCP lateralization effect was correlated with faster RT（r=-0.301,p=0.020）,and LPCP selective effect was correlated with smaller RT_CV（r=-0.285,p=0.029）.（3）In the ADHD group,smaller target MMN was corelated with higher severity of inattention symptoms（r=0.344,p=0.012）and hyperactivity/impulsivity symptoms（r=0.293,p=0.035）.more importantly,the lack of N2ac selective effect was corelated with higher severity of inattentive symptoms（r=0.287,p=0.039）.Conclusion:1.Both children with ADHD and TD children can localize to unilateral sound stimuli,that is,significant lateralization effects.2.During the temporal cascade,TD children could selectively attend to target stimuli throughout.Whereas children with ADHD had abnormal early sound detection and recognition,and mid-term selective focusing of attention.But as time progressed,a slight selectivity emerged during later attentional reorientation.3.School-aged TD children have developed an“adult-like”ability to balance auditory target selection and distractor suppression.The absence of N2ac in children with ADHD was correlated with higher severity of inattention symptoms,providing novel evidence supporting their dysfunctional auditory spatial selective attention.Part 2:Objective:To investigate whether dysfunctional auditory spatial selective attention in children with ADHD affects other higher cognitive abilities,such as visual working memory,reading ability,and mathematical abilities.Method:Participants were the same as in Study 1.A change detection task was used to explore visual working memory,and rapid automatic naming（RAN）was used to assess reading ability.Simple arithmetic computation,three-dimension mental rotation,and dot comparison in an online psychological experiment system were used to test mathematical abilities.And Pearson correlation was made between the above task performance and the EEG data related to auditory spatial selective attention in Study 1.Results:1.Comparisons between groups showed that children with ADHD had significantly lower visual working memory K values than children with TD（t=-3.425,p<0.001）,and marginally significant slower RAN times than TD children（t=1.974,p=0.051）.for the mathematical abilities,only the simple arithmetic computation was significantly smaller than that of TD children（t=-3.238,p=0.002）.2.The correlation results of performance and EEG data related to auditory spatial selective attention（with age and sex controlled）:（1）For children with ADHD,larger target N2ac lateralization effect was correlated with better mental rotation performance（r=-0.453,p=0.001）,while larger non-target N2ac lateralization effect was correlated with worse simple arithmetic computation performance（r=0.301,p=0.030）.The lack of N2ac selective effect was correlated with worse performance of K value,RAN times,simple arithmetic computation performance,and mental rotation（ps<0.040）.Both larger target LPCP lateralization effect and larger LPCP selective effect were correlated with better three-dimension mental rotation performance（ps<0.038）.（2）For TD children,larger Ta selective effect was correlated with better dot comparison performance（r=0.334,p=0.010）.Also,larger N2ac selective effect was correlated with better three-dimension mental rotation performance（r=-0.296,p=0.023）.Conclusion:1.Children with ADHD may indeed have deficits in visual working memory,reading ability,as well as deficits in parts of mathematical abilities such as numeracy.2.Auditory spatial selective attention may indeed associate with higher cognitive processes.The dysfunctional auditory spatial selective attention in children with ADHD was associated with poorer performance in visual working memory,reading ability,and mathematical abilities.