Abstract:

Effort plays a critical role in reward processing, which has been couched within two contradictory theories regarding effort as either a cost or a reward. On the one hand, effort is regarded as a cost whereby it reduces reward value, which has been articulated in the intrinsic cost model, the opportunity cost model, and the signal model. On the other hand, effort can boost the value of reward, which has been explained by the cognitive dissonance model, the learned industriousness model, and the need for cognition model. Both theories have been supported by converging evidence from animal studies, human behavioral studies, electrophysiological studies, and neuroimaging studies. Future research is needed to specify the definition of effort, integrate the competing theories in terms of the time course of effort expenditure, and explore potential factors that impact on effort.

Key words: effort, cost, reward