Cognitive resources predict value learning for outcome-irrelevant features

To establish accurate action-outcome associations in the environment, individuals must refrain from assigning value to outcome-irrelevant features. However, reinforcement learning studies have largely ignored the role of attentional control processes on credit assignment (the process of assigning value to one’s actions). In the current study, we examined the extent to which working memory – a system that can filter and block the processing of irrelevant information in one’s mind – predicted credit assignment to outcome-irrelevant task features. One hundred and seventy-four individuals completed working memory capacity and outcome-irrelevant learning estimates. Outcome-irrelevant learning was estimated in a reinforcement learning task where only stimulus’ visual features predicted reward, but not the response keys used to indicate one’s selection. As expected, we found a consistent tendency to assign value to the tasks’ response keys, reflecting outcome-irrelevant learning at the group level. However, we also found substantial individual differences, such that only 55% of participants demonstrated this effect. Importantly, working memory capacity significantly moderated individual differences in outcome-irrelevant learning; individuals with higher capacity were less likely to assign credit to the outcome-irrelevant feature (i.e., response key). We discuss the influence of working memory on outcome-irrelevant learning through the perspective of cognitive control failure.