Abstract
INTRODUCTION: Updating egocentric positions of objects of interest during self-motion is fundamental to our daily navigation. Past studies show we make systematic errors in the direction of the movement when updating these positions after lateral self-motion. However, the source of these errors is still largely unknown. To distinguish between the errors due to our perception of target position and errors in updating during movement, the present study measured errors in remembered target position with and without visually-simulated movements. METHODS: We used an Oculus Rift (CV1) to present targets (lateral positions: ±.75m, ±.5m, ±.25m, or 0m; simulated viewing distance 2m) briefly (0.5s) on a simulated projector screen while participants fixated a cross. After an idle period (7s) or a visually-induced lateral movement (left or right at ~0.14 m/s for 7s), they positioned a dot at the remembered target positions by pointing a hand-held controller. RESULTS: Participants underestimated target eccentricity when remembering target positions, with greater errors for more eccentric targets. After visually-induced lateral motion, errors were reduced for targets within the range of motion and increased for targets outside the range of motion. CONCLUSION: Our ability to update a remembered target’s position is affected by both its initial and final eccentricity and the perceived magnitude of the movement. People may be more accurate in updating the positions of targets within the perceived range of motion. Future experiments will extend these studies using physical motion and real targets.
Acknowledgement: VISTA, CVR