Computerized EEG analyses of autistic children.

Researchers hooked 30 autistic kids to a 16-channel EEG. They recorded five minutes of quiet rest.

The computer counted slow delta waves, alpha waves, and left-right balance. Same tests were run on two control groups matched for mental age and for chronological age.

Autistic children carried 40 % more slow-wave activity and 25 % less alpha than both control groups. Their EEG looked like the patterns you see in typical two-year-olds.

The two sides of the brain also acted more alike, showing weaker left-right asymmetry. The data fit a 'maturational-lag' story: autistic brains grow slower, not broken.

Wallander et al. (1983) saw the same lag earlier, using ear and finger tests instead of EEG. The 1986 EEG study sharpened the picture with numbers from the scalp.

Rochette et al. (2018) extended the idea to sleep. Autistic adults still show weak slow waves at night, linking the lag to overnight memory problems.

Wu et al. (2025) used fMRI BrainAGE and found sensorimotor networks maturing late, too. Three decades and three tools all point to the same delay.

Audras-Torrent et al. (2021) pooled 68 imaging papers and found less focal language activation in ASD. That meta-analysis includes the 1986 data, showing the lag holds across labs.

If a client's brain is running on 'toddler time,' don't rush skills that need older circuits. Break language or social targets into smaller steps and give longer practice windows. When you see slow progress, think 'late blooming,' not 'can't learn.'