Macro- and Microstates of Resting-State EEG in Children with Low-Functioning Autism

Objectives Resting-state EEG (rsEEG) offers unique advantages for examining brain activity in children with autism spectrum disorder (ASD) due to their challenges in following instructions and heightened sensory hypersensitivity. To investigate functional brain states, it is essential to focus on the temporal dynamics of rsEEG.Methods We applied two methods with different time resolutions (macrostate or k-means clustering of the continuous rsEEG segment and microstate analysis of shorter temporal EEG epochs) to study the transient states of brain electrical activity in several age groups of children. A total of 158 children with low-functioning ASD and 177 typically developing (TD) children aged 2 to 14 years participated in the study. The groups were matched for age, gender, and IQ.Results The results indicated that in the control group, micro- and macrostates exhibited increased age-related dynamics during maturation. We identified micro- and macrostates with similar topographies related to salience, sensory processing, and the default mode network (DMN). The coverage of macro- and microstates associated with sensory processing and DMN was significantly higher in children with ASD. Children with ASD displayed a shorter coverage of macro- and microstates with interhemispheric asymmetry compared to the TD group.Conclusions The obtained results support previous findings regarding atypical resting-state EEG microstate patterns in ASD when compared to TD children. Additionally, EEG microstates and macrostates exhibit age-related changes that differ between ASD and TD individuals. The findings related to EEG micro- and macrostates have promising implications for the diagnosis and rehabilitation of children with low-functioning autism.