Electroencephalogram (EEG) Hemispheric Asymmetry and Regional Power Distribution During Executive Functioning Tasks in Children with Suspected Specific Learning Disabilities: A Preliminary Study

Abstract

Background: Quantitative spectral analysis of electroencephalogram (EEG) signals has been widely applied to investigate the neurobiological underpinnings of neurodevelopmental disorders, including specific learning disabilities (SpLDs). Objective: To examine inter-hemispheric asymmetries and EEG power activation during executive task performance in children with suspected SpLDs identified through academic screening. Materials and Methods: A cross-sectional observational design was employed. Nineteen school-aged children with suspected SpLDs were recruited through teacher referral and academic screening using the Kasetsart Basic Academic Skills Test (KBAST). All participants met the inclusion criteria of average intelligence calculated as IQ of 70 or above, and below-average performance in at least one KBAST domain. EEG signals were recorded using an 8-channel system while participants performed the Tasks of Executive Control (TEC). Each EEG session lasted 15 to 20 minutes. Absolute power across nine frequency bands between 0.5 to 45 Hz, was computed using Fast Fourier Transformation (FFT). Hemispheric asymmetries were analyzed using Wilcoxon signed-rank tests, and regional differences were examined using Kruskal-Wallis tests with Games-Howell post hoc analysis. Results: The results indicated spectral differences in EEG power across hemispheric and regional sites during executive task performance. Children with suspected SpLDs showed distinct EEG power distribution during executive task performance. Right-hemisphere power was significantly greater than left-hemisphere power in the upper-theta (p=0.02) and lower-alpha (p=0.05) bands. Frontal regions exhibited significantly higher lower-delta (p=0.02) and upper-delta (p<0.001) activity than central regions. Low-frequency activity in delta, theta, and lower-alpha was most prominent at prefrontal and frontal sites. Conclusion: The findings indicate atypical hemispheric lateralization and elevated low-frequency EEG activity during executive task engagement in children with suspected SpLDs. The EEG indicated suboptimal neural resource allocation and clear hemispheric and regional asymmetries during executive task engagement in children with suspected SpLDs, but they should be interpreted cautiously given the small sample size and absence of a control group. Further controlled studies with larger samples are needed to clarify the specificity, developmental significance, and potential clinical relevance of these preliminary observations.