Synchronization in functional brain networks of children suffering from ADHD based on Hindmarsh-Rose neuronal model

Abstract

Attention Deficit Hyperactivity Disorder (ADHD) is one of the common psychological disorders in children, which causes improper recognition of others' emotions. These children often have very poor social interaction and a lack of self-confidence. Brain disorders are typically studied by investigating the functional connectivity of different areas in the brain networks of individuals and measuring synchronization. This study investigates synchronization in the simulated functional brain networks of 22 boys with ADHD and 22 healthy boys using electroencephalogram (EEG) signals during angry, happy, neutral, and sad emotions. In these simulated networks, a Hindmarsh-Rose neuronal model is considered for each network node. The edges' weights connecting these nodes represent the synchronization level between the EEG electrode pairs. By changing the coupling strength between the network nodes, different synchronization patterns in the ADHD and healthy brain networks can be observed in all four types of facial emotions. This study shows a higher synchronization, especially in happiness emotion in the frontal and occipital brain lobes of the ADHD group, responsible for human emotional and visual processing, respectively. Results also indicate the chimera phenomenon in both of the brain networks of ADHD and healthy individuals. However, this phenomenon occurs in the ADHD group at a lower coupling strength. These findings may represent a deficit in the brain's emotional and visual processing centers in the ADHD group, especially during the happy emotional stimuli.