Prefrontal tDCS results in enhanced visual search performance. Changes in visual search by group and set size (as previously reported in Wards et al. [2023]). All 5 groups show similar changes in RTs for set size 8 trials. However, both 1 mA left hemisphere (1 mA LH) and right hemisphere (1 mA RH) tDCS groups that trained on multitasking have greater performance improvements than sham for set sizes 12 and 16. Each point represents an individual’s change in RT from pre–post training. Positive values reflect an improvement in performance from pre–post training. Δ = change in, ** = strong evidence, *** = decisive evidence (Kass and Raferty 1995) for a difference between groups.