Frontal theta power prospectively associated with response inhibition

A proactive mechanism has been postulated to promote successful inhibition (Kenemans, 2015). Specifically, this mechanism is thought to operate before any action demanding or countermanding event has occurred. In the current study, we investigated whether EEG theta power could reflect this mechanism, in a sample of healthy individuals performing a stop-signal paradigm. By comparing frontal theta power preceding failed versus successful stop trials, we tested whether frontal theta is predictive of inhibition success. We hypothesized that proactive cognitive control manifests in frontal theta power preceding a countermanding go-stop event. Our results demonstrate that frontal theta is indeed higher preceding successful as compared to preceding failed stopping events. We also show that frontal theta power preceding stopping events is associated with Stop-Signal Reaction Times (SSRT), with a higher theta being indicative of shorter SSRTs. This association was not present for go-RT. This study may be the first to reveal a relationship between lower frontal theta power and subsequent stopping failure, suggesting thetas role in proactive response inhibition.