Fatigue influence on inhibitory control: Cardiovascular and performance findings elucidate the role of restraint intensity.

Various papers have detailed an analysis of behavioral restraint that provides suggestions regarding fatigue influence on inhibitory control. A well-known limited resource model by Baumeister suggests that fatigue should directly impair it. By contrast, the behavioral restraint analysis suggests-first-that fatigue might affect control indirectly by impacting the intensity of restraint. Second, fatigue should impair control consistently only when it leads people to withhold restraint effort. We evaluated these suggestions in an experiment that presented participants a task designed to induce low- or high- mental fatigue and then challenged them to maintain a neutral facial expression while watching a more- or less emotionally evocative film clip. As expected, cardiovascular assessments during the facial restraint period revealed interactional response patterns indicative of opposing fatigue influence on restraint intensity under low- as compared to high-evocativeness conditions. Also as expected, fatigue combined with evocativeness to produce a three versus one pattern of inhibitory control operationalized in terms of the duration of non-neutral facial displays. Control failure increased with evocativeness only when fatigue was high and increased with fatigue only when evocativeness was high. Findings support the restraint analysis suggestions, extend results from previous research, and bear out the promise of the restraint analysis for advancing understanding of inhibitory control.