Differences in the production and perception of communicative kinematics in autism

----FINAL VERSION: doi.org/10.1002/aur.2611 ----In human communication, social intentions and meaning are often revealed in the way we move. In this study, we investigate the flexibility of human communication in terms of kinematic modulation in a clinical population, namely, autistic individuals. The aim of this study was twofold: to assess 1) whether communicatively relevant kinematic features of gestures differ between autistic and neurotypical individuals, and 2) if autistic individuals use communicative kinematic modulation to support gesture recognition. We tested autistic and neurotypical individuals on a silent gesture production task and a gesture comprehension task. We measured movement during the gesture production task using a Kinect motion tracking device in order to determine if autistic individuals differed from neurotypical individuals in their gesture kinematics. For the gesture comprehension task, we utilized stick-light figures as stimuli and, by testing for a correlation between the kinematics of these videos and recognition performance, we assessed whether autistic individuals used communicatively relevant kinematic cues to support recognition. We found that 1) silent gestures produced by autistic and neurotypical individuals differ in communicatively relevant kinematic features, such as the number of meaningful holds between movements, and 2) while autistic individuals are overall unimpaired at recognizing gestures, they processed repetition and complexity, measured as the amount of submovements perceived, different than neurotypicals do. These findings highlight how subtle aspects of neurotypical behavior can be experienced differently by autistic individuals, and demonstrate the relationship between movement kinematics and social interaction in high-functioning autistic individuals.