Individuals with autistic-like traits show reduced lateralization on a greyscales task.

The team asked adults with high autistic traits to judge which side of a grey bar looked darker. The bar was identical on both sides, so normal brains pick the left side more often. This left-side pick is called pseudoneglect.

They compared the bias scores of high-trait adults to typical adults. No one in the study had an autism diagnosis; they were all neurotypical volunteers who scored high on an autism-trait questionnaire.

High-trait adults chose the left side less often. Their reduced leftward bias means weaker brain lateralization.

The weaker bias was tied to self-reported social difficulties, linking a simple visual choice to real-life social problems.

Ivy et al. (2017) repeated the idea with a line-bisection task and got the same pattern: high-trait adults show less leftward bias in physical space. Together the two papers build a picture that attention, not just vision, is skewed.

Jouravlev et al. (2020) moved from traits to diagnosed adults. Using brain scans, they found reduced language lateralization in people with ASD. The 2015 greyscales result now looks like the mild end of the same lateralization curve.

Frazier et al. (2018) then showed the bias is plastic. One short session of tDCS restored leftward bias in the same high-trait adults. The 2015 finding is not a fixed deficit; it can be nudged.

You can spot attention quirks in high-trait clients without long tests. Try the greyscales task as a quick screener: show the bar, record the choice, and note if they pick left less than 60% of the time. If they do, slow down instruction pacing and use clear left-right cues. The 2018 tDCS data also hint that brief attention drills or even lateralized flashcards might re-train bias, giving you a low-cost intervention to pilot in your next session.