The DSM-5 definition of autism spectrum disorders includes sensory issues and part of the sensory information that the brain continuously receives comes from kinesthetic reafference, in the form of self-generated motions, including those that the nervous systems produce at rest. Some of the movements that we self-generate are deliberate, while some occur spontaneously, consequentially following those that we can control. Yet, some motions occur involuntarily, largely beneath our awareness. We do not know much about involuntary motions across development, but these motions typically manifest during resting state in fMRI studies. Here we ask in a large data set from the Autism Brain Imaging Exchange repository, whether the stochastic signatures of variability in the involuntary motions of the head typically shift with age. We further ask if those motions registered from individuals with autism show a significant departure from the normative data as we examine different age groups selected at random from cross-sections of the population. We find significant shifts in statistical features of typical levels of involuntary head motions for different age groups. Further, we find that in autism these changes also manifest in non-uniform ways, and that they significantly differ from their age-matched groups. The results suggest that the levels of random involuntary motor noise are elevated in autism across age groups. This calls for the use of different age-appropriate statistical models in research that involves dynamically changing signals self-generated by the nervous systems.

DSM-5对自闭症谱系障碍的定义包括感觉问题，并且大脑持续接收的部分感觉信息来自动觉障碍，其形式为自发运动，包括神经系统在静止时产生的运动。我们自我产生的某些运动是有意为之，而某些运动是自发发生的，因此遵循我们可以控制的运动。但是，有些动议是非自愿的，很大程度上是在我们的意识之下。我们对发育过程中的非自愿运动了解不多，但是这些运动通常在功能磁共振成像研究的静止状态期间表现出来。在这里，我们从自闭症脑成像交换存储库中的大量数据中询问，头部非自愿运动的变异性的随机特征是否通常随年龄而变化。我们进一步询问自闭症患者注册的那些动议是否显示出与规范数据的重大差异，因为我们研究了从人群中随机选择的不同年龄组。我们发现不同年龄组的典型非自愿头部运动水平的统计特征发生了重大变化。此外，我们发现在自闭症中，这些变化也以不均匀的方式表现出来，并且与年龄匹配的人群有显着差异。结果表明，各个年龄段的自闭症患者的随机非自愿运动噪声水平均升高。这就要求在研究中使用与年龄相适应的不同统计模型，该模型涉及动态改变神经系统自身生成的信号。