Naturalistic movements enrich episodic memories but not their spatiotemporal structure

It remains unclear how episodic memories, our memories for past events, are generated from the rich sensory details encompassing everyday experience. Here, 40 healthy young participants navigated in a large-scale virtual environment under two conditions: an immersive-ambulatory condition, in which participants walked on a treadmill with full-body motion and head turns, or a restricted-movement condition, in which participants used a hand-held joystick to control gaze and position in virtual-reality while standing still. Participants then freely recalled their experience navigating in the virtual town. Analysis of verbal narratives revealed a double dissociation such that ambulation resulted in more detailed episodic elaborations, particularly those grounded in a first-person perspective, whereas restricted movement promoted more generalized spatial elaborations, particularly those not anchored to participants' point of view. These findings suggest that bodily cues contribute to the construction of episodic memory, while their absence may redirect attention toward external features of the environment. Participants also judged the relative direction of landmarks (space) and reproduced the amount of time they had spent navigating (time); however, objective indicators of spatiotemporal memory did not vary based on condition and, with one exception, did not correlate with subjective measures of memory quality. Together, these results suggest that the construction of vivid episodes is not necessarily tied to the precision of spatial and temporal encoding.