EEG Classification of ADHD and Normal Children Using Non-linear Features and Neural Network

Purpose: Attention-Deficit Hyperactivity Disorder (ADHD) is a neuro-developmental disorder that is characterized by hyperactivity, inattention and abrupt behaviors. This study proposes an approach for distinguishing ADHD children from normal children using their EEG signals when performing a cognitive task.

Methods: In this study, 30 children with ADHD and 30 agematched healthy children without neurological disorders underwent electroencephalography (EEG) when performing a task to stimulate their attention. Fractal dimension (FD), approximate entropy and lyapunov exponent were extracted from EEG signals as non-linear features. In order to improve the classification results, double input symmetrical relevance (DISR) and minimum Redundancy Maximum Relevance (mRMR) methods were used to select the best features as inputs to multi-layer perceptron (MLP) neural network.

Results: As expected, children with ADHD had more delays and were less accurate in doing the cognitive task. Also, the extracted non-linear features revealed that non-linear indices were greater in different regions of the brain of ADHD children compared to healthy children. This could indicate a more chaotic behavior of ADHD children while performing a cognitive task. Finally, the accuracy of 92.28% and 93.65% were achieved using mRMR method and DISR method using MLP, respectively.

Conclusions: The results of this study demonstrate the ability of the non-linear features to distinguish ADHD children from healthy children.