Chen, X.; Wiener, J.; Hegarty, M.; Wolbers, T.

Path integration and spatial updating refer to the integration of self-motion information during navigation to update start location and the positions of other locations, respectively. Even though path integration has been described as a fundamental process whose output may serve as a building block for other navigational computations like spatial updating, the exact relationship between path integration and spatial updating is unknown. Here we addressed this question with an eye-tracking behavioral experiment and a subsequent fMRI study. Despite experiencing identical self-motion cues, participants showed differential eye fixation patterns and responded more quickly during spatial updating than during path integration, casting doubt on the fundamental role of path integration. Neuroimaging results showed that the precuneus and the dorsal premotor cortex were more activated during spatial updating, but the precuneus had stronger functional connectivity with the thalamus and the frontal cortex during path integration. Further supporting this dissociation, the two tasks invoked distinct brain-wide inter-regional functional networks. Together, the combined findings of both experiments suggest that spatial updating and path integration are dissociable navigation processes supported by distinct behavioral and neural mechanisms, rather than one process operating on the basis of the other.