The effect of tDCS on inhibitory control in healthy older adults

Abstract

Highlights - This study aimed to examine the effects of transcranial direct current stimulation (tDCS) on right inferior frontal gyrus (rIFG) for inhibitory control in healthy older adults. - The results show that application of tDCS on rIFG does not improve inhibitory control in healthy older adults. Abstract Objectives: The present study examined the effects of tDCS on rIFG for inhibitory control in healthy older adults.

Methods: Twenty-five healthy older adults (60+) performed two inhibitory tasks (STOP-IT task and Go/No-Go task) in a double-blind cross-over design, after receiving either sham tDCS or actual tDCS (20 min, 2.0 mA, anodal rIFG; cathodal left supraorbital region). Outcome measures for inhibitory control were stop signal reaction time [(SSRT), (STOP-IT task)], reaction time and percentage of motor responses (Go/No-Go task). The STOP-IT task provided a measure of SSRT and mean signal-respond reaction time. The Go/No-Go task provided reaction time and a percentage of motor responses on Go and No-Go trials. The secondary outcomes were attention, fatigue and discomfort measured by the VAS scoring system at 3 time epochs (prior and after tDCS intervention and after completion of the tasks).

Results: Data analysis revealed no significant effect between the tDCS and sham condition for inhibitory control in both the STOP-IT task and the Go/No-Go task. However, the secondary outcomes showed some significant differences in attention, fatigue and discomfort among the 3 time epochs (prior to the intervention,