Cortical variability in the sensory-evoked response in autism.

Perez et al. (2015) watched adult brains with fMRI while they felt simple touch or heard beeps.

They counted how much each person’s own brain response jumped around from trial to trial.

All adults had autism and normal IQ; the team compared their brain jitter to adults without autism.

The autism group had bigger moment-to-moment swings in sensory brain activity.

This ‘brain noise’ was stable within each person, pointing to a personal biomarker.

Patton et al. (2020) saw the same jumpy pattern in kids, but used EEG and reaction-time tests, showing the idea holds across ages and tools.

Locurto et al. (1980) first noticed jumpy brain-stem responses in autistic kids, so the new work moves the finding up from brain-stem to cortex.

He et al. (2018) looks like a clash: preschoolers with autism showed less variability in the default-mode network, not more. The gap is about age and brain system—toddlers may start with rigid networks that later flip to noisy sensory circuits in adulthood.

If sensory brain responses are naturally unstable in many autistic learners, brief, consistent stimuli may help during teaching. You can test this by using the same sound level, same picture size, and same room lighting across trials, then watch if skill acquisition smooths out. The study also flags that ‘variable response’ is not one-size-fits-all: check age and task type before you label it a deficit.