Modulating attentional biases of adults with autistic traits using transcranial direct current stimulation: A pilot study.
One 20-minute zap over the right parietal spot gave high autistic-trait adults a quick leftward attention boost.
01Research in Context
What this study did
The team gave one dose of mild brain stimulation to neurotypical adults. All scored high on an autism-trait survey.
They placed a small tDCS sponge over the right rear parietal spot. The current ran for 20 minutes while each adult did a greyscales line-bisection task.
The goal was to see if the zap could shift the typical left-side attention bias that high-trait adults usually lack.
What they found
After the real stimulation, high-trait adults showed a clear leftward tilt on the greyscales task.
The sham session produced no tilt. The effect vanished within hours, but it proved the bias can move.
How this fits with other research
Whiting et al. (2015) first showed that high autistic-trait adults have almost no leftward bias on the same task. The new study flips that deficit around with one shot of tDCS, so the 2018 paper extends the 2015 finding into the changeable column.
van Timmeren et al. (2016) recorded brain waves and found weaker distractor suppression in the same population. Together the two studies map both the neural signature and a quick lever for shifting it.
Fitzgerald et al. (2015) saw weak dorsal attention network wiring in teens with ASD. The tDCS target sits right in that network, giving a biological reason the stimulation worked.
Why it matters
You now know that spatial attention in high-trait adults is not fixed; it can be nudged in minutes. While tDCS is not clinic-ready, the greyscales task offers a fast, non-social probe you can use during assessments. If a client shows little bias, consider adding spatial-cueing games or left-side prompting to your skill packages. The study also reminds us to test attention markers in sub-threshold clients before labeling a skill deficit as permanent.
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02At a glance
03Original abstract
UNLABELLED: While neurotypical individuals over-attend to the left-side of centrally-presented visual stimuli, this bias is reduced in individuals with autism/high levels of autistic traits. Because this difference is hypothesized to reflect relative reductions in right-hemisphere activation, it follows that increasing right-hemisphere activation should increase leftward bias. We administered transcranial direct current stimulation (tDCS) over the right posterior parietal cortex to individuals with low levels (n = 19) and high levels (n = 19) of autistic traits whilst they completed a greyscales task. Anodal tDCS increased leftward bias for high-trait, but not low-trait, individuals, while cathodal tDCS had no effect. This outcome suggests that typical attentional patterns driven by hemispheric lateralization could potentially be restored following right-hemisphere stimulation in high-trait individuals. Autism Res 2018, 11: 385-390. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Attentional differences between individuals with and without autism may reflect differences in underlying activation of the left and right hemispheres. In this study, we combine an attentional task that reflects relative hemispheric activation with non-invasive cortical stimulation, and show that attentional differences between healthy individuals with low and high levels of autistic-like traits can be reduced. This outcome is encouraging, and suggests that other aspects of attention in autism (e.g., face processing) may stand to benefit from similar stimulation techniques.
Autism research : official journal of the International Society for Autism Research, 2018 · doi:10.1002/aur.1895