Auditory brainstem evoked responses in autistic children.

Doctors taped tiny earphones and scalp sensors to autistic and non-autistic kids. They played soft clicks and measured how fast the sound traveled up the brainstem. The test is called brain-stem evoked response, or BSER. It takes minutes and needs no talking or pointing.

Every autistic child had slower, jumpier brainstem signals. The wait time was longer and the timing changed from click to click. Control kids gave steady, quicker answers. The pattern hints that the brainstem itself is noisy in autism.

Gillberg et al. (1983) ran the same test three years later. They saw odd BSERs in only one-third of autistic kids, not all. The kids with odd results also had floppy muscle tone and almost no words. Method mattered: Locurto et al. (1980) mixed all kids together, while C et al. split them by features. The studies look opposite but both show brainstem timing can drift in autism.

Spates et al. (2013) moved the idea down to toddlers. They used a quick stapedial-reflex test and again found longer, uneven wait times. Chen et al. (2019) tracked the same children for ten months. Typical kids locked into stable timing; autistic kids stayed erratic. Together the chain shows the brainstem lag is real, starts early, and stays wobbly.

Patton et al. (2020) and Perez et al. (2015) pushed the "wobble" story up to cortex and even to grown-ups. Whether you record brainstem clicks, cortical ERPs, or fMRI blobs, autistic brains show more moment-to-moment scatter. The 1980 paper lit the first signal that this noise lives at the most basic relay station.

You now have a fast, objective red flag. A five-minute BSER or acoustic reflex test can show if a child’s brainstem timing is shaky. Pair it with checklists for hypotonia or language delay to spot kids who need auditory supports early. No cooperation, no language, no problem—the click does the work.