Brain Oscillatory Coupling during Motor Control as a Potential Biomarker for Autism Spectrum Disorders: a comparative study

Abstract

Abstract Background Autism spectrum disorder (ASD) often involves dysfunction in general motor control and motor coordination, in addition to core symptoms. However, the neural mechanisms underlying motor dysfunction in ASD are poorly understood. To elucidate this issue, we focused on brain oscillations and their coupling in the primary motor cortex (M1). Methods We recorded magnetoencephalography in 18 children with autism spectrum disorder, aged 5 to 7 years, and 19 age- and IQ-matched typically-developing children while they pressed button during a video-game-like motor task. We measured motor-related gamma (70 to 90 Hz) and pre-movement beta oscillations (15 to 25 Hz) in the primary motor cortex. To determine the coupling between beta and gamma oscillations, we applied phase-amplitude coupling to calculate the statistical dependence between the amplitude of fast oscillations and the phase of slow oscillations. Results We observed a motor-related gamma increase and a pre-movement beta decrease in both groups. The autism spectrum disorder group exhibited a reduced motor-related gamma increase ( t(35) = 2.412, p = 0.021 ) and enhanced pre-movement beta decrease ( t(35) = 2.705, p = 0.010 ) in the ipsilateral primary motor cortex. We found the phase-amplitude coupling that the high-gamma activity modulated by the beta rhythm in the primary motor cortex. Phase-amplitude coupling in the ipsilateral primary motor cortex was reduced in the autism spectrum disorder group compared with the control group ( t(35) = 3.610, p = 0.001 ). Using oscillatory changes and their coupling, linear discriminant analysis classified autism spectrum disorder and control groups with high accuracy (area under the receiver operating characteristic curve 97.1%). Limitations Further studies with larger sample size and age range of data are warranted to confirm these effects. Conclusions The current findings revealed alterations in oscillations and oscillatory coupling reflecting the dysregulation of a motor gating mechanism in ASD. These results may be helpful for elucidating the neural mechanisms underlying motor dysfunction in ASD, suggesting the possibility of developing a biomarker for ASD diagnosis.