Autism & Developmental

Motion and form coherence detection in autistic spectrum disorder: Relationship to motor control and 2:4 digit ratio.

Milne et al. (2006) · Journal of autism and developmental disorders 2006
★ The Verdict

Kids with autism often move clumsily and some need slower visual motion cues, so pair motor drills with clear, unhurried demos.

✓ Read this if BCBAs running motor or social-skills groups for school-age clients with ASD.
✗ Skip if Clinicians who work solely with verbal behavior and never use movement tasks.

01Research in Context

01

What this study did

Kelley et al. (2006) watched how kids with autism see moving dots and shapes.

They also checked finger length. The pointer-to-ring-finger ratio is a quiet marker of fetal testosterone.

Last, they timed how fast each child could tap and wiggle.

02

What they found

Most kids with autism moved more slowly and less smoothly than same-age peers.

Their 2D:4D ratio was lower, hinting at higher prenatal testosterone.

Oddly, only a small slice of the group struggled to spot coherent motion.

03

How this fits with other research

Manning et al. (2013) ran the same dot test and found the motion problem shows up only at slow speed. That explains the mixed 2006 result.

Sajith et al. (2008) used plaid patterns and saw zero motion deficit. Different pictures, different answer — an apparent contradiction that warns us to pick our visual tools with care.

Hilton et al. (2012) and Hopkins et al. (2011) later showed big motor gaps in siblings and in gait. Together the papers say motor trouble is a core, not side, feature of ASD.

Burnham Riosa et al. (2023) stretched the link into adults with mild traits, proving the motion-motor tie can linger across life.

04

Why it matters

If a learner with autism looks lost during group movement games, test slow-speed motion perception and basic motor timing. Add clear visual cues, extra demo, or partner taps. Track 2D:4D only if you study hormones; for day-to-day therapy, focus on motor goals that boost play and social entry.

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Show the next action at half-speed before asking the child to copy it.

02At a glance

Intervention
not applicable
Design
quasi experimental
Population
autism spectrum disorder
Finding
mixed

03Original abstract

Children with autistic spectrum disorder and controls performed tasks of coherent motion and form detection, and motor control. Additionally, the ratio of the 2nd and 4th digits of these children, which is thought to be an indicator of foetal testosterone, was measured. Children in the experimental group were impaired at tasks of motor control, and had lower 2D:4D than controls. There were no group differences in motion or form detection. However a sub-group of children with autism were selectively impaired at motion detection. There were significant relationships between motion coherence detection and motor control in both groups of children, and also between motion detection, fine motor control and 2D:4D in the group of children with autistic spectrum disorder.

Journal of autism and developmental disorders, 2006 · doi:10.1007/s10803-005-0052-3