Humans incorporate trial-to-trial working memory uncertainty into rewarded decisions

In daily life, working memory plays an important role in action planning and decision-making. However, both the informational content of memory and how that information is used in decisions is poorly understood. To investigate this, we conducted a memory experiment where people not only reported an estimate of a remembered stimulus, but also made a rewarded decision designed to reflect memory uncertainty. Reported memory uncertainty is correlated with estimation error, showing people incorporate their trial-to-trial memory quality into rewarded decisions. Moreover, memory uncertainty can be combined with other sources of information; after we induced prior beliefs about stimuli probabilities, we found that estimates shifted towards more frequent colors, with the shift increasing with reported uncertainty. The data is best predicted by models where people incorporate their trial-to-trial memory uncertainty with potential rewards and prior beliefs, highlighting the importance of studying working memory as a process integrated with decision-making.