Physiological Evidence for the Time-dependent Resolution of Response Conflicts

Abstract Cognitive control encapsulates the mental processes that support goal-directed behavior and overcome habitual/automatic drives. Traditional RT approaches obscure the temporal dynamics of conflict resolution. We recently proposed the use of a forced-response paradigm in combination with the response preparation model (RPM) to reveal how processing related to goal-directed and automatic responses unfolds over time during the conflict resolution process. However, this model relies on overt behavior and trials when participants make an error, leaving it unclear if the insight the model provides can be used to infer the dynamic mental states that occur when conflict resolution is successful. Partial errors—subthreshold muscle activation of the incorrect response on incongruent trials before the correct response—offer a solution. Partial errors act as a physiological window into the timing of the habitual process. Across two experiments, participants completed forced-response versions of the Simon and flanker tasks while EMG was recorded from both hands. We demonstrate that the RPM accurately captures behavioral performance and that the estimations of the habitual process by the RPM correspond with the timing of partial errors. Importantly, replacing the habit process in the RPM with the timing of partial errors preserved the model's ability to accurately predict behavior. These findings offer converging behavioral, computational, and physiological evidence for the timing of the habitual response process in conflict tasks and affirm the utility of the forced-response method and RPM in examining conflict resolution.