Grey-Matter Thickness of the Left But Not the Right Primary Visual Area Correlates with Autism Traits in Typically Developing Adults.

Researchers scanned the brains of neurotypical adults. They measured how thick the grey matter was in each side of the primary visual area.

Each adult also filled out a self-report form about autism traits. The team asked: does thicker visual cortex match higher trait scores?

Only the left side mattered. Thicker left V1 went hand-in-hand with higher autism-trait scores.

The right side showed no link. Brain activity levels did not relate to trait scores at all.

Anthony et al. (2020) seems to say the opposite. They found less left-side activation in autistic adults watching videos. The two studies differ because one looks at structure and the other at real-time activity.

Xiao et al. (2014) set the stage. Toddlers with ASD already had extra grey matter. Beck et al. (2021) now show that even small trait shifts in neurotypical adults show up in the same brain area.

Deng et al. (2021) add sex to the picture. Females with ASD have more male-typical brain asymmetry. Together these papers build a map of how grey-matter asymmetry tracks autism features across age, sex, and diagnosis.

If you assess adults who report social or sensory quirks, remember their visual cortex may hold clues. A quick MRI is not practical in clinic, but knowing the link exists can guide your interpretation of self-report tools. It also reminds us that autism traits sit on a continuum in the general public, not just in diagnosed clients.