EEG Spectral Power in Children with Autistic Spectrum Disorders: Heterogeneity of the Group

Abstract

A population of children (mean age 6.05 years) with autistic spectrum disorders (ASDs) was divided into two groups depending on whether further development was supposed to be of an autistic type (AT) or to have a transition to a schizotypal type (SCH-T). Features of the baseline EEG spectral power (SP) were studied in the AT and SCH-T groups and a group of children with the schizophrenia spectrum disorders (SchSDs) in comparison with a group of normally developing children of the same age. The SPs of the θ and α rhythms in the anterior cortex were higher than normal in the SCH-T and AT groups, while the α-rhythm SP in the posterior cortex was decreased. The AT group displayed lower activities of the θ and α rhythms, especially in the posterior regions. The α-rhythm SPs in the occipital regions were reduced in all test groups. A right predominance of the α rhythm was observed in two groups, SchSD and SCH-T. An increased representation of the γ rhythm in the frontal-central and temporal regions was observed in the AT group. The heterogeneity of the groups of children with ASDs was presumably associated with a transition from ASD to SchSD, and possible predictors of this transition are discussed.