The pleasure of effort: Cognitive challenges trigger hedonic physiological responses

Challenging prominent neuroscientific conceptions of effort as generally aversive, recent research suggests that people can learn to seek effort. Importantly, it is unknown whether people once they learn to value effort for its instrumentality, experience pleasure when engaging in effortful tasks. In this preregistered study (N = 194), we tested the hypothesis that effort-contingent rewards in a cognitive task will induce reward-related hedonic facial responses before, during, or after effortful engagement in a subsequent non-incentivized task. The results showed that effort-contingent reward enhanced participants' facial responses in the zygomaticus major (ZM) muscle after effort exertion (consumption phase) in the subsequent non-incentivized task, especially in high-difficulty trials. Electrical activity in the ZM was positively associated with subjective pleasure ratings in the experimental group when solving difficult trials, suggesting that it is implicitly tracking the hedonic value of effort. Our findings show that effort-contingent reward promotes effort-related reward experience, indicating that effort itself becomes intrinsically rewarding as experienced pleasure after effort exertion.