Contrast and the justification of effort

When humans are asked to evaluate rewards or outcomes that follow unpleasant (e.g., high-effort) events, they often assign higher value to that reward. This phenomenon has been referred to ascognitive dissonance or justification of effort. There is now evidence that a similar phenomenon can be found in nonhuman animals. When demonstrated in animals, however, it has been attributed to contrast between the unpleasant high effort and the conditioned stimulus for food. In the present experiment, we asked whether an analogous effect could be found in humans under conditions similar to those found in animals. Adult humans were trained to discriminate between shapes that followed a high-effort versus a low-effort response. In test, participants were found to prefer shapes that followed the high-effort response in training. These results suggest the possibility that contrast effects of the sort extensively studied in animals may play a role in cognitive dissonance and other related phenomena in humans.     

Physical and cognitive effort discounting of hypothetical monetary rewards

Effort discounting refers to the decrease in the subjective value of a reward as the effort required to obtain the reward increases. The main aims of this study were to ascertain whether the amount of the reward affects the steepness of the effort discounting process for hypothetical monetary rewards, to identify whether this steepness depends on the type of effort that is required, and to determine whether the steepness of different types of effort covary at the individual level. Two types of effort were studied under hypothetical choice situations: physical effort and cognitive effort. Both physical and cognitive effort discounting were well described by the hyperbolic model. Large rewards were discounted less steeply than small rewards for both types of effort. This finding agrees with the results of prior studies which have found that larger rewards have greater motivational power. In addition, the steepness of physical effort discounting was positively correlated with the steepness of cognitive effort discounting, which suggests that the effort discounting process is a trait‐like characteristic within an individual.     

Payment and value: The generation of an evaluation standard and its effect on value

Three studies explored the relationship between the reward that individuals receive for engaging in an activity and the value that they subsequently place on that activity. In Experiments 1 and 2, subjects engaged in an activity more when they had previously received a moderate amount of reward than when they had received either a small or a large reward. Experiment 3 indicated that the shape of this function was determined, in part, by the value the activity had before the reward was give. These results, coupled with those of previous studies in the effort justification paradigm, suggest that reward and cost can influence activity value similarly, through the operation of simple comparison processes as predicted by personal comparison theory. Implications for social judgment, associative, self-perception, and dissonance perspectives were discussed.     

Monetary reward increases attentional effort in the flanker task

An important question is whether monetary reward can increase attentional effort in order to improve performance. Up to now, evidence for a positive answer is weak. Therefore, in the present study, the flanker task was used to examine this question further. Participants had to respond sooner than a certain deadline in a flanker task. One group of participants received a performance-contingent monetary reward, whereas the other group earned a fixed amount of money. As a result, monetary reward significantly improved performance in comparison with the control group. The analysis of speed-accuracy trade-off functions revealed that monetary reward increased attentional effort, leading to an enhanced quality of stimulus coding. Little evidence was found that reward also improved selective spatial attention.     

Effect of failure/success feedback and the moderating influence of personality on reward motivation

While motivation to pursue goals is often assumed to be a trait-like characteristic, it is influenced by a variety of situational factors. In particular, recent experiences of success or failure, as well as cognitive responses to these outcomes, may shape subsequent willingness to expend effort for future rewards. To date, however, these effects have not been explicitly tested. In the present study, 131 healthy individuals received either failure or success feedback on a cognitive task. They were then instructed to either ruminate or distract themselves from their emotions. Finally, they completed the Effort Expenditure for Rewards Task, a laboratory measure of reward motivation. Results indicate that participants who received failure feedback relied more strongly on the reward magnitude when choosing whether to exert greater effort to obtain larger rewards, though this effect only held under conditions of significant uncertainty about whether the effort would be rewarded. Further, participants with high levels of trait inhibition were less responsive to reward value and probability when choosing whether to expend greater effort, results that echo past studies of effort-based decision-making in psychological disorders.     

Response rate correlates with indifference points in a delay‐discounting procedure

To study how effort affects reward value, we replicated Fortes, Vasconcelos and Machado's (2015) study using an adjusting‐delay task. Nine pigeons chose between a standard alternative that gave access to 4 s of food, after a 10 s delay, and an adjusting‐delay alternative that gave access to 12 s of food after a delay that changed dynamically with the pigeons' choices, decreasing when they preferred the standard alternative, and increasing when they preferred the adjusting alternative. The delay value at which preference stabilized defined the indifference point, a measure of reward value. To manipulate effort across phases, we varied the response rate required during the delay of the standard alternative. Results showed that a) the indifference point increased in the higher‐response‐rate phases, suggesting that reward value decreased with effort, and b) in the higher‐response‐rate phases, response rate in the standard alternative was linearly related to the indifference point. We advance several conceptions of how effort may change perceived delay or amount and thereby affect reward value.     

Reformative self‐control and discounting of reward value by delay or effort1

Abstract: The relation between reformative self‐control and discounting of reward value by delay or effort was examined. Thirty‐two Japanese undergraduates were selected based on their scores on a standardized pencil and paper test of self‐control, the Redressive–Reformative Self‐Control Scale ( Sugiwaka, 1995 ). The subjects indicated their preference (i) between a hypothetical 100 000 yen reward available with various delays and a certain reward of variable amount available immediately; or (ii) between a hypothetical 100 000 yen reward available with various efforts and a certain reward of variable amount available without effort. The discounting of delayed reward value was described well by a hyperbolic function proposed by Mazur (1987 ). The slopes of the delayed discounting curves were steeper for subjects who scored low on the Reformative Self‐Control Scale, which is a measure of reformative self‐control and a subscale of the Redressive–Reformative Self‐Control Scale. The discounting by effort was also described well by the hyperbolic function. The slopes of the effortful discounting curves did not correlate to those of the delayed discounting curves. The slopes were not systematically different across the groups of subjects with different scores on the reformative self‐control scale.     

Cognitive dissonance and psychotherapy: The role of effort justification in inducing weight loss

The role of effort justification in psychotherapy was examined. It was hypothesized that the effort involved in therapy, plus the conscious decision to undergo that effort, leads to positive therapeutic changes through the reduction of cognitive dissonance. An experiment was conducted in which overweight subjects attempted to lose weight through one of two forms of “effort therapy”. These therapies were bogus in that they were based solely on the expenditure of effort on a series of cognitive tasks that were unrelated to any existing techniques or theory addressing weight loss. One of the therapies called for a high degree of effort while the degree of effort in the second therapy was low. A no-treatment control group was also included. It was predicted that greater weight loss would occur for high-effort than low-effort or control subjects, and that this weight loss would be maintained or increased over time. Results supported these predictions. Over an initial 3-week period, high-effort subjects lost slightly more weight than low-effort subjects or controls. A 6-month follow-up revealed that the effects of effort on weight loss had increased and were highly significant. Reliable differences remained even 1 year after the initial experimental sessions. Possible mechanisms mediating the dissonance effect were discussed, as were several alternative explanations.     

努力：成本还是奖赏?

努力(Effort)与奖赏系统关系密切。当前关于努力在奖赏加工中的作用存在两个截然相反的观点：努力是一种成本还是一种奖赏?理论模型包括：其一, 努力是一种成本, 会降低奖赏的价值, 相应的理论解释包括内部成本模型、机会成本模型及信号模型等; 其二, 努力能够提升奖赏的价值, 相应的理论解释包括认知失调和努力的合理化模型、习得性勤奋理论及认知需求理论等。这两种观点均得到了来自于动物学、行为学、电生理学以及神经影像学等证据的支持。未来研究需要对努力准确定义, 从时间进程角度对努力的理论进行整合, 进一步考察努力的相关影响因素。     

The role of effort type and intensity in children's decisions about effort-based outcomes

Despite the importance of persistence in early learning, we know little about how children reason about outcomes that result from their efforts. Here we examined the role of effort type (i.e., physical vs. cognitive) and intensity (i.e., high vs. low effort) in shaping children's decision making about effort-based rewards. Five- to 7-year-olds (N = 133) were assigned to one of four conditions (High Physical Effort, Low Physical Effort, High Cognitive Effort, Low Cognitive Effort) and completed a series of tasks to construct a toy. Tasks varied in the type (physical/cognitive) and intensity (high/low) of effort required to complete them. After constructing their toy, children completed a series of tasks to probe how much they valued that toy. Across conditions, children preferred their toy and gave it a higher monetary value, relative to a stranger's. However, when choosing their toy came at a cost, children no longer preferred it. Only children who built their toy through either cognitive or low effort were willing to incur a cost for their toy. Older children, across conditions, were also more likely to incur a cost for their toy. These findings demonstrate that by age five, children are sensitive to variations in effort type and intensity, and these factors shape how they evaluate effort-based rewards.     

Subjective cognitive effort: a model of states, traits, and time

Self-regulation theories were used to develop a dynamic model of the determinants of subjective cognitive effort. The authors assessed the roles of malleable states and stable individual differences. Subjective cognitive effort and perceived difficulty were measured while individuals performed an air traffic control task. As expected, Conscientiousness moderated the effort trajectory. Individuals with high Conscientiousness maintained subjective cognitive effort at high levels for longer than their counterparts. There were also individual differences in reactions to perceptions of task difficulty. The intra-individual relationship between perceived difficulty and subjective cognitive effort was stronger for individuals with low ability or low Conscientiousness than for their counterparts. A follow-up study showed that the measures of perceived difficulty and subjective cognitive effort were sensitive to a task difficulty manipulation as well as that the relationship between perceived difficulty and subjective cognitive effort held after controlling for self-set goal level. These findings contribute to the self-regulation literature by identifying factors that influence changes in subjective cognitive effort during skill acquisition.     

Effect of effort and deadlines on consumer product returns

While extant research has examined return policies as a combination of time and effort, we investigate both the independent and interactive impacts of time and effort on consumer decisions to return or retain products. We find that decreasing return deadlines can have the counterintuitive effect of increasing return rates under some conditions. Using construal level theory, we propose that perceived effort (both physical and cognitive) mediates the effect of return policy on return rates leading to suppressed returns. Further, when deadlines are framed as durations between store visits, overall product returns are exacerbated except when perceived effort is high.     

Reducing fears and increasing assertiveness: The role of dissonance reduction

In the research paradigm known as effort justification, people engage in an effortful activity in order to attain a goal. As a result, the goal becomes more attractive. Two experiments were conducted to test the notion that the effort justification sequence can account for the positive changes that result from psychotherapy. In the first experiment, subjects who were afraid to approach a snake underwent one of two types of effortful therapy. One was a modified form of an anxiety-producing therapy known as “implosive therapy”; the other was merely a set of physical exercises. It was reasoned, on the basis of cognitive dissonance theory, that the expenditure of effort would lead to a positive change in the ability to approach the snake but only under conditions of high decision freedom. Half of the subjects in each of the therapy conditions participated with high choice; the other half with low choice. Subjects' improvement in their approach to snakes was assessed. A main effect for decision freedom was predicted and found independently of the type of effort that subjects expended. A second experiment conceptually replicated the findings of the first experiment. Subjects who wanted to become more assertive participated in an effortful, physical exercise therapy or in a modified form of the standard treatment for fear of assertiveness. The results of the 2 × 2 factorial experiment again showed a main effect for decision freedom such that high choice subjects became more assertive. The findings were discussed in terms of dissonance and attribution theories as well as for implications for future consideration of psychotherapy.     

Effects of Frustration Increase and Decrease on Percentage of Short Interresponse Times

The finding by H. L. Armus (1986) that short (less than 1 s) interresponse times (IRTs) occur with greater frequency at higher levels of required lever-pressing effort was investigated. It has been hypothesized that greater percentages of short IRTs at higher effort requirements are an expression of frustration (S. Boyer & R. Carroll, 1980); in the present study, between-groups manipulations of effort and reward combinations were made in an attempt to increase and decrease relative frustration and thereby increase and decrease percentages of short IRTs. The subjects were 17 experimentally naive, male Long-Evans rats. Manipulation of effort requirements and reward magnitudes yielded both an increase and a decrease in percentage of short IRTs. The rats switched from low effort and high reward to high effort and low reward demonstrated the greatest increase in percentage of short IRTs, whereas the rats switched from low effort and low reward to high effort and high reward demonstrated a decrease in short IRTs.     

Dissociation of reward and effort sensitivity in methcathinone‐induced Parkinsonism

Methcathinone‐induced Parkinsonism is a recently described extrapyramidal syndrome characterized by globus pallidus and substantia nigra lesions, which provides a unique model of basal ganglia dysfunction. We assessed motivated behaviour in this condition using a novel cost‐benefit decision‐making task, in which participants decided whether it was worth investing effort for reward. Patients showed a dissociation between reward and effort sensitivity, such that pallidonigral complex dysfunction caused them to become less sensitive to rewards, while normal sensitivity to effort costs was maintained.     

Investigating the influence of an effort–reward interaction on cognitive fatigue in individuals with multiple sclerosis

This study examined whether an alteration in the effort–reward relationship, a theoretical framework based on cognitive neuroscience, could explain cognitive fatigue. Forty persons with MS and 40 healthy age- and education-matched cognitively healthy controls (HC) participated in a computerized switching task with orthogonal high- and low-demand (effort) and reward manipulations. We used the Visual Analog Scale of Fatigue (VAS-F) to assess subjective state fatigue before and after each condition during the task. We used mixed-effects models to estimate the association and interaction between effort and reward and their relationship to subjective fatigue and task performance. We found the high-demand condition was associated with increased VAS-F scores (p < .001), longer response times (RT) (p < .001) and lower accuracy (p < .001). The high-reward condition was associated with faster RT (p = .006) and higher accuracy (p = .03). There was no interaction effect between effort and reward on VAS-F scores or performance. Participants with MS reported higher VAS-F scores (p = .02). Across all conditions, participants with MS were slower (p < .001) and slower as a function of condition demand compared with HC (p < .001). This behavioural study did not find evidence that an effort–reward interaction is associated with cognitive fatigue. However, our findings support the role of effort in subjective cognitive fatigue and both effort and reward on task performance. In future studies, more salient reward manipulations could be necessary to identify effort–reward interactions on subjective cognitive fatigue.     

I'm worth more than you! Effects of reward interdependence on performance,cohesion, emotion and effort during team competition

ObjectivesTo examine the effects of reward structures on the performance of a motor task. To evaluate the effects of reward interdependence on performance, cohesion, emotion, and effort during intergroup (team) competition.DesignAn experimental design was used to compare the effects of reward interdependence (no, low, high) on performance of a strength and endurance task.MethodParticipants (N = 111) performed a 3-min handgrip task as a member of a team of four under three reward interdependence conditions (no; low, with an even split of prize money; high, with an uneven split of prize money) in head-to-head competitions against another team. Task performance was assessed using the cumulative force production total. Task-related cohesion, enjoyment, anxiety and effort were measured using self-report scales.ResultsPerformance was better with rewards than no reward, and better with high than low reward interdependence. Team cohesion was highest with low reward interdependence. Effort was greater with rewards than no reward. Anxiety and enjoyment did not vary among the reward conditions. Mediation analyses indicated that increased cohesion mediated improvements in performance from no reward to low reward interdependence conditions, and increased effort mediated improvements in performance from no reward to both low and high reward interdependence conditions.ConclusionPerformance of a simple physical task in team competition was facilitated by rewards, with optimal performance associated with unequal rewards (i.e., performance-related pay). The benefits of performing with rewards compared to no rewards were explained by increased cohesion and effort. Social interdependence theory can help explain performance of simple motor tasks during team-based competitions. The findings have implications for the pay structures adopted by sports teams.     

Learned industriousness.

Extensive research with animals and humans indicates that rewarded effort contributes to durable individual differences in industriousness. It is proposed that reinforcement for increased physical or cognitive performance, or for the toleration of aversive stimulation, conditions rewards value to the sensation of high effort and thereby reduces effort's aversiveness. The conditioning of secondary reward value to the sensation of effort provides a dynamic mechanism by which reinforced high performance generalizes across behaviors. Applications to self-control, moral development, and education are described.     

Transfer of effort across behaviors

A series of experiments investigated the effects of required force and number of responses per reinforcer upon the subsequent performance of a second behavior. In the first experiment, a group of rats required to complete five round trips in an alley per food pellet subsequently bar-pressed for food at a greater rate than a group rewarded for each round trip or a control group that did not receive the alley experience. In the second experiment, a group required to apply a 70-g bar-press force subsequently shuttled for food at a greater rate than a group required merely to touch the lever or a control group that did not undergo the lever-press manipulation. The third experiment found that the force effect persisted across all five test sessions and was attributable to differences both in response speed and interresponse time. The fourth experiment found that both the necessary bar-press force and number of bar presses per reward affected subsequent shuttling in extinction. Two alternative interpretations of these results were compared: (a) the degree of accustomed effort per reinforcer becomes a generalized component of instrumental behavior or (b) high effort increases the habituation frustration-produced disruptive responses.