Abnormal Reactivity of Brain Oscillations to Visual Search Target in Children With Attention-Deficit/Hyperactivity Disorder

Abstract

Background: Previous studies have shown that impaired goal-directed alpha lateralization and functional disconnection within attention networks during the cue period are significant features of attention-deficit/hyperactivity disorder (ADHD). This study aimed to explore the role of brain oscillations in the visual search process, focusing on target-induced posterior alpha lateralization, midfrontal theta synchronization, and their functional connection in children with ADHD.

Methods: Electroencephalograms were recorded from typically developing (TD) children (n = 72) and children with ADHD (n = 96) while they performed a visual search task.

Results: Both the TD and ADHD groups showed significant midfrontal theta event-related synchronization (ERS) and posterior alpha lateralization. Compared with TD children, children with ADHD showed significantly lower theta ERS and higher target-induced alpha lateralization. TD children showed a positive trial-based correlation between theta ERS and alpha lateralization and a negative correlation between theta ERS and reaction time variability. However, all these correlations were absent in children with ADHD.

Conclusions: Abnormal brain oscillations in children with ADHD indicate insufficient executive control function and the compensation of attention networks for attention deficits in visual selective attention. Cross-frequency disconnection reflects the common deficiency of executive control in the gating of target information. Our findings provide novel evidence for interpreting the features of brain oscillations during stimulus-driven selective attention in children with ADHD.

Keywords: Alpha lateralization; Attention-deficit/hyperactivity disorder; Children; Disconnection; Selective attention; Theta synchronization.