Temporal Processing Instability with Millisecond Accuracy is a Cardinal Feature of Sensorimotor Impairments in Autism Spectrum Disorder: Analysis Using the Synchronized Finger-Tapping Task.

Morimoto et al. (2018) asked people to tap their finger in time with a steady beat. They compared autistic individuals to neurotypical controls. The team measured how close each tap landed to the beat, down to the millisecond.

The autistic group showed more wobble in their tap timing. Their taps drifted farther from the beat than controls. This millisecond-level scatter was large enough to tell the groups apart.

Franich et al. (2021) extended the same idea to speech. They found that autistic kids who tapped poorly also spoke with uneven rhythm. The same timing glitch showed up in both finger and tongue moves.

De Meo-Monteil et al. (2019) seems to disagree. They saw equal or better timing in autistic adults when the task was visual, not auditory. The gap closes once you notice the switch: Chie used sound cues; Rosanna used flashing lights.

Dudley et al. (2019) reviewed 45 timing papers and confirm the pattern. Simple motor tasks like finger tapping separate the groups. Complex time judgments do so even more.

You now have a one-minute, low-cost screen. Hand the client a tablet and let them tap to a metronome. If their millisecond scatter is high, it flags domain-general timing issues that could feed into language, social, or motor goals. Pair the result with Kathryn’s speech findings and you can justify rhythm-based interventions such as hand-drill warm-ups before articulation practice.