How stimulus and task complexity affect monitoring in high-functioning adults with autism spectrum disorder.

Koolen et al. (2014) asked high-functioning adults with autism to watch a screen.

Simple shapes popped up one at a time. The adults had to press a key when the same shape appeared twice in a row.

Later the shapes were replaced with hard-to-name abstract pictures. The team timed how fast and how accurately each person responded.

When the shapes were easy, adults with autism kept pace with typical adults.

When the pictures were complex, the same adults slowed down much more than the control group.

Their accuracy stayed okay, but the extra thinking time jumped as soon as semantic detail increased.

Samson et al. (2006) saw the same pattern in hearing tests: simple tones favored autistic listeners, complex sound streams did not.

Takahashi et al. (2013) looked at neurotypical college students who scored high on autistic traits. Those students did NOT slow down when picture arrays got harder. This seems like a clash, but Junichi used spatial clutter, not meaning. The two studies together show the bottleneck is about meaning, not just visual load.

Li et al. (2021) tracked kids’ eyes while they remembered dot patterns. Autistic children used fewer memory shortcuts and looked longer at single dots. The adult slowdown in Sophieke’s work mirrors the child eye-movement data: both groups skip efficient chunking when complexity rises.

If you give an adult client a long verbal chain or a busy visual schedule, build in extra wait time. Swap abstract icons for photos only after the skill is solid. Start simple, then layer meaning once the response is quick and calm.