Delayed rewards weaken human goal directed actions

Goal-directed actions are sensitive to the causal association between actions and outcomes, as well as the value of those outcomes. Such sensitivity diminishes when actions become habitual. Based on recent findings in animals, we tested if delaying outcomes relative to actions would weaken sensitivity to outcome revaluation and reduce action rates. In three experiments (N = 290), participants made fictitious investments in companies within contexts that provided either immediate or delayed feedback. After training, participants were informed of a change in markets which affected both companies (one improved and the other worsened). Across all experiments, action rates were lower in the delayed-feedback condition, and outcome revaluation was stronger in the immediate-feedback condition. In addition, self-reported action-outcome knowledge was weaker in the delayed-feedback condition. These findings suggest that delays in reinforcement weaken the action-outcome association critical for goal-directed control. We discuss the potential mechanisms underlying this phenomenon in light of a contemporary theory of goal-directed behavior.