Decision processes underlying effort avoidance and their relationship with metacognition.

Effort-based decision making relies on cost-benefit computations that require individuals to evaluate expected rewards against the effort needed to obtain them. However, the temporal dynamics underlying the neural processing of reward and effort, as well as the influence of metacognitive ability on this process, remain unclear. The present study investigated these dynamics by recording electroencephalogram (EEG) data while participants performed an effort-based decision-making task and by assessing their metacognitive ability. Decoding analyses of the EEG data revealed that neural representations of effort-avoidance decisions emerged early (approximately 260 ms after stimulus onset) and remained stable over time. Crucially, representational similarity analysis showed that the brain processes reward information before effort information. Although both types of information were primarily represented in parietal electrodes, effort processing engaged a broader network that also included frontal regions. Behaviorally, higher metacognitive ability was associated with better task performance and reduced sensitivity to immediate rewards. These findings suggest a sequential decision-making process in which individuals first evaluate potential rewards and subsequently integrate information about the required effort when deciding whether to avoid effort. Furthermore, higher metacognitive ability appears to buffer against immediate reward impulses, thereby promoting long-term goal-directed behavior. Overall, this study provides direct neural evidence for the temporal dynamics of cost-benefit computation and highlights the critical role of metacognition in effort-based decision making.