Impaired motor function occurs in autism spectrum disorders, as well as the core symptoms of repetitive behaviours, and difficulty with social interaction. Individuals with autism often present with faulty perception of movement and problems with motor control. Presence of gross and fine motor skill impairments suggest a basic flaw in movement kinematics.
This study investigated 14 adults with ASD and 15 controls to see if abnormal movements contribute to the perception aberration and motor control symptoms. Trajectory, velocity, jerk and sinusoidal arm movements were measured and compared between ASD adults and controls. Also the perceptions of what was natural and unnatural movements were recorded by participants.
An IR Vicon motion tracking system was used to assess velocity, acceleration and jerk during a movement execution task including sinusoidal arm movements. In the perception task, ASD adults classified whether specific virtual movements were abnormal or normal.
In this study, ASD adults showed greater kinematic acceleration and velocity and more jerky movements compared with controls. The level of atypical movements correlated with their perception of the degree of their kinematic abnormality, and severity of autism symptoms measured by ADOS.
The authors suggested that atypical kinematics in ASD adults may contribute to loss of motor control and distort their perception of the actions of others.
Cook JL, Blakemore S-J, Press C. Atypical basic movement kinematics in autism
spectrum conditions. Brain 2013: 136; 2816-24.
