Inhibitory control training and transcranial direct current stimulation of the pre-supplementary motor area: behavioral gains and transfer effects.

Inhibitory control is a critical part of executive function and an important cognitive process in daily life. It is currently unclear how to optimally improve inhibitory control ability through behavior training and other interventions. Here, we explored the factors that influence inhibition control training in two experiments, focusing on the gains and transfer effects of training. Experiments 1 and 2 investigated the effects of anodal transcranial direct current stimulation (tDCS) over the pre-supplementary motor area and an increase in training duration on the training effect for inhibitory control, respectively, as well as the transfer effects when participants completed the Stroop and directed forgetting tasks. The results showed a stable training effect in relation to inhibitory control and a transfer effect for the Stroop task. Anodal tDCS in the pre-supplementary motor area could effectively improve inhibitory control ability, but not further enhance the training effect for inhibitory control. Moreover, increasing the training duration did not enhance the training effect for inhibitory control. The addition of tDCS and the extension of training duration failed to enhance the training effect, indicating that there may be a limitation of improvement in inhibitory control. The findings provide evidence regarding the further intervention effects of behavioral training and tDCS.