Modulating attentional biases of adults with autistic traits using transcranial direct current stimulation: A pilot study

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.