Transcranial Direct Current Stimulation Decreases P3 Amplitude and Inherent Delta Activity During a Waiting Impulsivity Paradigm

Abstract Background One of the main features of addictive behaviors is the inability to wait for an action, that is, the waiting impulsivity. It has been suggested that potential therapeutic tools for addiction, such as transcranial Direct Current Stimulation (tDCS), might focus on this inability. Nonetheless, whereas there is consensus about the role of prefrontal cortex on impulsivity behavior, the effects of tDCS in waiting impulsivity and underlying electrophysiological (EEG) markers are still not clear. Objective The study aimed the neuromodulation of right inferior frontal gyrus during a task designed to elicit premature responses, while EEG markers important in reward anticipation (i.e., cue and target-P3 and underlying delta/theta activity) were studied. Methods Forty healthy subjects participated in two experimental sessions, where they received active and sham tDCS while performing a premature responding task and the EEG was recorded. At next, participants performed two control tasks to evaluate transfer effects for delay discounting and motor inhibition abilities. Results Active tDCS decreased amplitude in cue-P3, target-P3, and delta activity during target-P3. On the other hand, active tDCS increased the discounting of future rewards in small values in comparison with sham, while no tDCS effects were found in motor inhibition. Conclusion These findings suggest tDCS-induced modulation of the P3 component and underlying oscillatory activity during waiting impulsivity. Moreover, these changes were associated with differences in the discounting of future rewards. Thus, the current study suggests the usefulness of tDCS in modulating impulsive processes and the relationship between P3, the inherent delta activity, and reward processing.