Fourie Emily, Lu Szu-Ching, Delafield-Butt Jonathan, Rivera Susan M
Department of Psychology, University of California, Davis, Davis, CA, USA.
Center for Mind and Brain, University of California, Davis, Davis, CA, USA.
J Autism Dev Disord. 2025 Mar;55(3):873-890. doi: 10.1007/s10803-024-06240-6. Epub 2024 Jan 27.
Autistic individuals often exhibit motor atypicalities, which may relate to difficulties in social communication. This study utilized a smart tablet activity to computationally characterize motor control by testing adherence to the two-thirds power law (2/3 PL), which captures a systematic covariation between velocity and curvature in motor execution and governs many forms of human movement. Children aged 4-8 years old participated in this study, including 24 autistic children and 33 typically developing children. Participants drew and traced ellipses on an iPad. We extracted data from finger movements on the screen, and computed adherence to the 2/3 PL and other kinematic metrics. Measures of cognitive and motor functioning were also collected. In comparison to the typically developing group, the autistic group demonstrated greater velocity modulation between curved and straight sections of movement, increased levels of acceleration and jerk, and greater intra- and inter-individual variability across several kinematic variables. Further, significant motor control development was observed in typically developing children, but not in those with autism. This study is the first to examine motor control adherence to the 2/3 PL in autistic children, revealing overall diminished motor control. Less smooth, more varied movement and an indication of developmental stasis in autistic children were observed. This study offers a novel tool for computational characterization of the autism motor signature in children's development, demonstrating how smart tablet technology enables accessible assessment of children's motor performance in an objective, quantifiable and scalable manner.
自闭症个体常常表现出运动异常，这可能与社交沟通方面的困难有关。本研究利用一款智能平板电脑活动，通过测试对三分之二次幂定律（2/3 PL）的遵循情况，以计算方式表征运动控制，该定律捕捉了运动执行中速度和曲率之间的系统协变关系，并支配着多种形式的人类运动。4至8岁的儿童参与了本研究，其中包括24名自闭症儿童和33名发育正常的儿童。参与者在iPad上绘制和描绘椭圆。我们从屏幕上的手指运动中提取数据，并计算对2/3 PL的遵循情况以及其他运动学指标。还收集了认知和运动功能的测量数据。与发育正常的组相比，自闭症组在运动的弯曲和直线部分之间表现出更大的速度调制、更高的加速度和急动度水平，以及在几个运动学变量上更大的个体内和个体间变异性。此外，在发育正常的儿童中观察到了显著的运动控制发展，但自闭症儿童中未观察到。本研究首次考察了自闭症儿童对2/3 PL的运动控制遵循情况，揭示了整体运动控制能力的下降。观察到自闭症儿童的运动不太流畅、更加多变，且有发育停滞的迹象。本研究为儿童发育中自闭症运动特征的计算表征提供了一种新颖的工具，展示了智能平板电脑技术如何以客观、可量化和可扩展的方式实现对儿童运动表现的便捷评估。
