Low-Frequency Gamma Oscillations in ADHD Children: Neural Features and Digital Training Effects

Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. Studies have identified visual perceptual dysfunction in ADHD patients, which may reflect an overactivated perceptual processing pattern. Given the critical role of gamma oscillations in attention and perception, this study aimed to explore the value of low-frequency gamma oscillations (31–45 Hz) as a biomarker for visual perceptual abnormalities in ADHD. A total of 86 children with ADHD and 52 typically developing (TD) children were included for comparative analysis, with follow-up assessments conducted on 57 children with ADHD who completed a 3-month digital training program. The results revealed that: In the frontal region, the difference in gamma power between eyes-open and eyes-closed states was significantly lower in ADHD compared to TD. In the occipital region, children with ADHD exhibited significantly higher gamma oscillation power than TD children. However, this aberrant activity was significantly reduced after training, approaching TD levels. Correlation analysis demonstrated that the degree of pre-training gamma activity deviation was positively associated with symptom improvement. In summary, these findings confirm the presence of abnormal low-frequency gamma oscillations in both the frontal and occipital regions of ADHD children, and further indicate that these abnormalities can be normalized through digital training. Additionally, gamma activity may serve as a predictor of intervention efficacy. Therefore, gamma oscillations hold potential as a biomarker for ADHD and an outcome measure for therapeutic interventions.