Without Blinking an Eye: Proactive Motor Control Enhancement

While most cognitive control enhancement studies have focused on reactive inhibition paradigms, enhancement of proactive control of urge-driven behaviors has been relatively neglected. With the aim of focusing on the proactive components of cognitive control over motor output, we designed a simple, ecologically valid eye blinking suppression task and applied transcranial direct current stimulation (tDCS) over the right inferior frontal gyrus (rIFG). Fifty-three subjects randomly allocated to three different stimulation groups underwent active or sham stimulation, subsequently performing eye blinking and stop signal tasks. Results showed that anodal stimulation over the rIFG increased the ability to suppress blinks compared to sham and active control stimulation. In addition, the rIFG group demonstrated a general slowdown of the stop signal reaction time, implying proactive control enhancement. Herein, we discuss our results with regard to previous findings as well as possible interventions in clinical populations.