Electroencephalogram complexity analysis in children with attention-deficit/hyperactivity disorder during a visual cognitive task

ABSTRACT

Objective: The aim of this study was to investigate electroencephalogram (EEG) dynamics using complexity analysis in children with attention-deficit/hyperactivity disorder (ADHD) compared with healthy control children when performing a cognitive task. Method: Thirty 7–12-year-old children meeting Diagnostic and Statistical Manual of Mental Disorders–Fifth Edition (DSM–5) criteria for ADHD and 30 healthy control children underwent an EEG evaluation during a cognitive task, and Lempel–Ziv complexity (LZC) values were computed. There were no significant differences between ADHD and control groups on age and gender. Results: The mean LZC of the ADHD children was significantly larger than healthy children over the right anterior and right posterior regions during the cognitive performance. In the ADHD group, complexity of the right hemisphere was higher than that of the left hemisphere, but the complexity of the left hemisphere was higher than that of the right hemisphere in the normal group. Conclusion: Although fronto-striatal dysfunction is considered conclusive evidence for the pathophysiology of ADHD, our arithmetic mental task has provided evidence of structural and functional changes in the posterior regions and probably cerebellum in ADHD.

Keywords:

• Attention-deficit/hyperactivity disorder
• electroencephalogram
• lempel–ziv complexity
• cognitive task
• mental activity

Acknowledgements

The authors also wish to thank those who helped in conducting this project, especially Ali Sheikhani, Ali Moti Nasrabadi and Mohammad Parvaneh for cooperation in signal recording and their great advice. Also, the authors would like to thank the Research Editing and Consulting Program of the International Neuropsychological Society (INS) and Rachel Fazio for language editing during the drafting of this paper.

Additional information

Funding

We acknowledge the financial support of Tehran University of Medical Sciences through a grant from Psychiatry and Psychology Research Center [grant number 16534].