When effort matters: Expectations of reward and efficacy guide cognitive control allocation

The amount of mental effort we invest in a task is influenced by the reward we can expect if we perform that task well. However, some of the rewards that have the greatest potential for driving these efforts (e.g., jobs, grants) are partly determined by factors outside of one9s control. In such cases, effort has more limited efficacy for achieving one9s desired outcome. We have proposed that people integrate information about the expected reward and efficacy for effort to determine the expected value of control, and then adjust their control (i.e. mental effort) allocation accordingly. Here we test key predictions this makes about behavior and neural activity. We show that participants invest more control in a task when this control is more rewarding and more efficacious, and that these incentive components separately modulate EEG signatures of incentive evaluation and subsequent control allocation. Our findings support the prediction that individuals combine considerations of worth and worthwhileness to determine how they will invest their efforts.