Effort-based decision-making:A value-based dissection and arousal-focused synthesis

Work often leads to better outcomes in terms of health, nutrition, and reproductive success, suggesting that work execution should be favored by natural selection. However, work also involves expending energy and time, costs that biological systems aim to limit. Indeed, work is often accompanied by the subjectively aversive experience of effort, which motivates work avoidance. Accordingly, decision-makers need to trade off the expected benefits of the goal their work aims to achieve with the anticipated effort costs before engaging in any action. While such trade-offs are relatively well-characterized, effort-based decision-making involve several other essential components, including the representation of anticipated effort and its comparison with experienced effort, which allows learning. These components and their relation to arousal received considerably less attention. To thoroughly dissect effort-based decision-making, we here synthesize the framework of value-based decision-making and expand it with work preparation, execution and recovery subprocesses. This systematizes existing research, highlights the specificities of effort-based decision-making, and identifies understudied components. Moreover, we use this framework to analyze (neuro)physiological commonalities and differences between motor and cognitive effort. Finally, we propose a novel, arousal-based model of effort suggesting that required increases in arousal give rise to effort and serve as a common currency that effort indexes and effort-based decisions aim to minimize.