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). We recorded magnetoencephalography in 18 children with ASD, aged 5 to 7 years, and 19 age- and IQ-matched typically-developing children while they pressed a button during a video-game-like motor task. The motor-related gamma (70 to 90 Hz) and pre-movement beta oscillations (15 to 25 Hz) were analyzed in the primary motor cortex using an inverse method. 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. We observed a motor-related gamma increase and a pre-movement beta decrease in both groups. The ASD group exhibited a reduced motor-related gamma increase and enhanced pre-movement beta decrease in the ipsilateral primary motor cortex. We found phase-amplitude coupling, in which high-gamma activity was modulated by the beta rhythm in the primary motor cortex. Phase-amplitude coupling in the ipsilateral primary motor cortex was reduced in the ASD group compared with the control group. Using oscillatory changes and their couplings, linear discriminant analysis classified the ASD and control groups with high accuracy (area under the receiver operating characteristic curve: 97.1%). The current findings revealed alterations in oscillations and oscillatory coupling, reflecting the dysregulation of motor gating mechanisms 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.

自闭症谱系障碍（ASD）除了核心症状外，通常还包括一般运动控制和运动协调功能障碍。但是，对ASD运动功能障碍的神经机制了解甚少。为了阐明这个问题，我们重点研究了大脑振动及其在初级运动皮层（M1）中的耦合。我们记录了18名5至7岁的ASD儿童和19名年龄和智商相匹配的典型发育儿童，他们在进行视频游戏般的运动任务时按了按钮，并记录了脑磁图。使用反向方法在初级运动皮层中分析了与运动有关的伽玛（70至90 Hz）和运动前的β振动（15至25 Hz）。为了确定β和伽马振荡之间的耦合，我们应用了相位-振幅耦合来计算快速振荡的振幅和慢速振荡的相位之间的统计依赖性。我们观察到两组运动相关的伽玛升高和运动前β降低。ASD组在同侧原发性运动皮层中显示出与运动相关的伽马升高减少和运动前β降低增强。我们发现了相-幅耦合，其中高伽马活动由初级运动皮层的β节律调节。与对照组相比，ASD组同侧原发性运动皮层的相幅耦合降低。使用振荡变化及其耦合，线性判别分析可以对ASD和对照组进行高精度分类（接收机工作特性曲线下的面积为97.1％）。当前的发现揭示了振荡和振荡耦合的改变，反映了ASD中的电机门控机制的失调。这些结果可能有助于阐明ASD运动功能障碍的神经机制，提示开发用于ASD诊断的生物标志物的可能性。