Rewarding cognitive effort increases the intrinsic value of mental labor.

Current models of mental effort in psychology, behavioral economics, and cognitive neuroscience typically suggest that exerting cognitive effort is aversive, and people avoid it whenever possible. The aim of this research was to challenge this view and show that people can learn to value and seek effort intrinsically. Our experiments tested the hypothesis that effort-contingent reward in a working-memory task will induce a preference for more demanding math tasks in a transfer phase, even though participants were aware that they would no longer receive any reward for task performance. In laboratory Experiment 1 (n = 121), we made reward directly contingent on mobilized cognitive effort as assessed via cardiovascular measures (ß-adrenergic sympathetic activity) during the training task. Experiments 2a to 2e (n = 1,457) were conducted online to examine whether the effects of effort-contingent reward on subsequent demand seeking replicate and generalize to community samples. Taken together, the studies yielded reliable evidence that effort-contingent reward increased participants' demand seeking and preference for the exertion of cognitive effort on the transfer task. Our findings provide evidence that people can learn to assign positive value to mental effort. The results challenge currently dominant theories of mental effort and provide evidence and an explanation for the positive effects of environments appreciating effort and individual growth on people's evaluation of effort and their willingness to mobilize effort and approach challenging tasks.

Foundational assumption reasonable but uncertain.

We offer thoughts on Shadmehr and Ahmed's foundational assumption that behavioral intensity (vigor) is proportional to the perceived value of outcomes driving behavior (incentives). The assumption is reasonable considering classical motivational thought and scholarship in related literatures but called into question by an influential contemporary theory of motivation by Brehm. Brehm's theory suggests that the assumption is warranted in some, but not all, performance circumstances. Furthermore, proportionality between vigor and value might be generated through a deliberative goal-setting process rather than through intrinsic neural linkages.

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.

Ability influence on effort and associated cardiovascular responses: Nocebo-Placebo evidence that perception is key.

Studies have documented the predictive utility of an integrative analysis of ability influence on effort and cardiovascular response. An assumption is that influence is driven by perception. We evaluated this altering ability perception through negative (nocebo) or positive (placebo) suggestion. Participants ingested a pill having been told it would reduce or enhance cognitive clarity. They then were presented a math task with the chance to earn an incentive if they met a low- or high performance standard. Analyses indicated higher reports of clarity during work among participants provided positive clarity instructions and a crossover clarity instruction x performance standard interaction for heart rate response. Responses were stronger for positive instruction participants when the standard was high, but stronger for negative instruction participants when it was low. Findings provide distinctive support for the assumption and suggest a fresh strategy for evaluating the impact of nocebo/placebo and other interventions on subjective experience.

Mortality salience, effort, and cardiovascular response to a bar-press challenge: Remarkably nuanced effects of a death prime on heart performance.

We presented participants with a bar-pressing challenge relevant to their identity after having exposed them to a prime that made their mortality more or less salient. For some participants, difficulty was low; for others, it was high; for the rest, it was unfixed. As expected, heart pre-ejection period responses-reflecting heart contraction force-were (a) stronger under high-salience conditions when difficulty was high and unfixed, but (b) low regardless of salience when difficulty was low. Findings bear out conceptually and extend results from a previous experiment. In doing so, they add substantively to a new line of support for terror management theory and document the predictive utility of a proposed blended analysis of associated effort processes. The blended analysis speaks to the way in which motives to manage existential terror should convert into active goal striving and to the impact that existential threat might have on aspects of autonomic arousal.

Outsiders' Thoughts on Generating Self-Regulatory-Depletion (Fatigue) Effects in Limited-Resource Experiments.

We offer thoughts pertaining to purported conceptual and replication crises that have been discussed in relation to the limited-resource model (LRM) of self-control, functioning as crisis outsiders who have been conducting related research concerned with determinants and cardiovascular correlates of effort. Guiding analyses in our laboratory convey important lessons about experimental generation of the now-classic LRM self-regulatory-fatigue effect on control. They do so by drawing attention to conditions that must be met in fatigue-induction and fatigue-influence phases of relevant experiments. One fundamental lesson is that even highly standardized fatigue-induction protocols cannot be expected to consistently allow definitive tests of this effect. Another is that the effect might emerge consistently only in a behavioral-restraint "sweet spot" of sorts-a multidimensional motivational space wherein rested study participants view restraint as possible and worthwhile and fatigued participants do not. Implications are identified and discussed.

Circadian mismatch and cardiovascular response to a performance challenge: Larks in morning and evening work sessions.

We presented morning chronotype ("Lark") university undergraduate volunteers a more or less difficult Sternberg-type recognition memory task either in the morning (8-11 am) or in the evening (5-8 pm) with instructions that they could win a prize if they were 85% successful. We established morning chronotype using the Composite Scale for Morningness (Smith et al., 1989), employing a tertile split on a pool of scale scores that ranged from 13 (extreme eveningness) to 55 (extreme morningness). Participants had scores above 37, with most participants identifying as White/Caucasian, Hispanic/Latino, or Black/African-American. Among women (final sample n = 81), systolic blood pressure and mean arterial pressure responses assessed during work formed a crossover pattern, being positively correspondent to difficulty in the morning but negatively correspondent to difficulty in the evening. Heart rate and heart pre-ejection period responses ran parallel in the morning but not the evening. Among men (final sample n = 41), cardiovascular responses differed neither with difficulty nor with time. Findings for women support the extension of a recent analysis of fatigue influence on effort and associated cardiovascular responses to the phenomenon of circadian mismatch. Findings for men do not support the extension but should be interpreted guardedly in light of prohibitively low cell ns and unexpected findings on key subjective measures.

Naturally-occurring fatigue and cardiovascular response to a simple memory challenge.

Participants first completed a state affect checklist that included a fatigue (energy-tiredness) index and a measure of mental sharpness. They then were presented a simple memory challenge. In the first minute of the two-minute work period, heart rate responses (1) rose with values on the fatigue index, and (2) fell with values on the measure of mental sharpness. In the second minute of the work period, the responses were unrelated to fatigue index and mental sharpness values. Follow-up analysis indicated mental sharpness mediation of fatigue influence on heart rate in Minute 1. First minute findings add substantively to the body of evidence supporting recent suggestions that fatigue can lead people to try harder and experience stronger cardiovascular responses when confronted with simple challenges. They also support the suggestion that fatigue might exert its influence on cardiovascular responses to a mental challenge by diminishing cognitive clarity, that is, by obscuring thought. Second minute findings are contrary to the fatigue suggestions, but could indicate that memorization was accomplished in the first minute. A practical implication of the first minute results is that real-world fatigue could elevate health risk by enhancing CV responses to mundane daily tasks.

Success importance and urge magnitude as determinants of cardiovascular response to a behavioral restraint challenge.

Decades of research have investigated a conceptual analysis concerned with determinants and cardiovascular correlates of effort in people confronted with performance challenges, that is, opportunities to alter some course of events by acting. One suggestion is that effort and associated cardiovascular responses should be determined jointly by the difficulty of meeting a challenge and the importance of doing so. The present experiment tested this in a context involving behavioral restraint, that is, effortful resistance against a behavioral impulse or urge. Participants were presented a mildly evocative violent film clip (restraint difficulty low) or a strongly evocative violent film clip (restraint difficulty high) with instructions to refrain from showing any facial response. Success was made more or less important through coordinated manipulations of outcome expectancy, ego-involvement and social evaluation. As expected, SBP responses assessed during the work period were proportional to clip evocativeness - i.e., the difficulty of the restraint challenge - when importance was high, but low regardless of clip evocativeness when importance was low. Findings conceptually replicate previous cardiovascular results and support extension of the guiding analysis to the behavioral restraint realm.