Fig. 1.

Path integration task. A) Illustration of the path integration task. A subject wearing the VR goggles goes to the indicated location A (yellow flag), and then to a different indicated location B (red flag), and finally returns to the starting point. Point X is the final position, which is hence the point that the subjects consider to be the starting position. The path integration error (the distance between the subject’s final position and the actual starting point), and angular error (the rotation angle between the straight line connecting the goal and the starting point, and the straight line connecting the goal and point X) were measured. B) Demonstration of the VR equipment, with a subject wearing 3D VR goggles seated on a swivel chair during the task. C) An example of the environment that is observed from the goggles, showing the yellow flag.