Reduced precision of motor and perceptual rhythmic timing in autistic adults

Recent results suggest that autistic individuals find it challenging to temporally coordinate their actions with predictable external cues, as indicated, for instance, by lower accuracy in synchronizing finger taps to an auditory metronome compared with their non-autistic peers. However, it is not yet clear whether these difficulties are driven primarily by motor or perceptual impairments. We recruited autistic and non-autistic participants for an online study which tested both finger tapping synchronization and continuation as well as purely perceptual (non-motoric) rhythmic timing. We fractionated each participant’s synchronization results into several individual-specific parameters representing error correction, motor noise, and internal time-keeper noise, and also investigated error-correcting responses to small timing perturbations in metronome timing. Contrary to previous work, we did not find strong evidence for reduced tapping error correction. However, we found compelling evidence for noisier internal rhythmic time-keeping in the synchronization, continuation, and perceptual components of the experiment. These results suggest that noisier rhythmic timing processes underlie some sensorimotor coordination challenges in autism.