Discrete movements in ASD children: comparison between the isochrony principle and Fitts' law

International audienceRecent studies on animal models have suggested that Autism Spectrum Disorders (ASD) could be related with a cerebellum dysfunction (Jaber, 2017). Because the cerebellum is particularly involved in the control of fine motricity, we compared the production of handwriting and pointing discrete movements in ASD and neurotypical (NT) children. Because these two tasks follow two motor laws, the isochrony principle and Fitts’ law, we can have clear expectations in terms of tasks success criteria.Using a digitizer, 24 NT and 27 ASD children (6-12 years) had to produce five size of “e” letters in cursive mode and 16 pointing movements with 4 difficulty indexes. In the two tasks the results show that, although ASD children respect the motor laws which characterize the production of movements, they are significantly slower compared with NT. Thereby, ASD children seemed to manage differently the difficulty. These results will be discussed in the framework of the cerebellum dysfunction hypothesis of ASD