Primate Gaze Behavior Reflects Change of Mind in a Naturalistic Navigation Task

Revising a decision while acting on it is a fundamental aspect of natural behavior, yet the underlying computations are difficult to track in real time. To explore how such belief updates unfold, we tested whether eye movements reveal a subject's change of mind during a naturalistic navigation task with a binary target choice. Humans and monkeys were required to navigate to one of two goal locations presented either simultaneously or sequentially in a virtual environment where explicit position cues were absent. Our findings reveal that gaze continuously tracks the latent variable, including changes of mind. We found that the target tracking accuracy before the second target is even presented during sequential target trials predicts whether the subject's navigational goal persists (first target choice) or changes (second target choice). These results underscore the importance of gaze in action planning and changes of mind, supporting the hypothesis that eye movements embody not only the current latent variable but also its uncertainty.

Humans and monkeys virtually navigated to one of two sequentially presented goals.Humans and monkeys prefer a cost-efficient goal, but the introduction of a new goal may sway their initial decisions.Eye movements predict change of decision by tracking the chosen goal location.Eye movements convey latent information for future navigation planning.

1. Primates virtually navigate and select one of two sequentially presented goals.2. Sequential goals prompt humans and monkeys to alter their initial decision, reflecting a tradeoff between memory uncertainty and action cost.3. Eye movements predict change of decision by tracking the invisible target location.4. Eye movements convey task-related latent variables for navigation.