Computational mechanisms underlying latent value updating of unchosen actions

Current studies suggest that individuals estimate the value of their
choices based on observed feedback. Here, we ask whether individuals also
update the value of their unchosen actions, even when the associated
feedback remains unknown. One hundred and seventy-eight individuals
completed a multi-armed bandit task, making choices to gain rewards. We
found robust evidence suggesting latent value updating of unchosen actions
based on the chosen action’s outcome. Computational modeling results
suggested that this effect is mainly explained by a value updating
mechanism whereby individuals integrate the outcome history for choosing
an option with that of rejecting the alternative. Properties of the
deliberation (i.e., duration/difficulty) did not moderate the latent value
updating of unchosen actions, suggesting that memory traces generated
during deliberation might take a smaller role in this specific phenomenon
than previously thought. We discuss the mechanisms facilitating credit
assignment to unchosen actions and their implications for human
decision-making.