Figure 2

The three spatial-cue conditions. Participants were assigned to either the egocentric, the allocentric, or the combined condition. The footsteps (not shown in the task) represent exemplary paths that participants walked in each condition, to encode the locations of two objects (a plant and an umbrella). Left: The egocentric condition contained no spatial landmarks, and the distance and direction to each object were encoded from a fixed viewpoint (the red semicircle). On every trial, participants started at the red semicircle, walked to the object, and made a perceptual judgment. The object then disappeared, and participants walked back to the red semicircle. Next, a new object was shown, and the procedure was repeated. See video 1 for further details. Middle: In the allocentric condition, no fixed viewpoint was used as different viewpoints were used. On every trial, participants started at a temporary red circle, walked to the object, and made a perceptual judgment. The object then disappeared, and participants walked to another red circle (which appeared in a different location than before). However, participants could code the locations of the objects relative to environmental landmarks. Next, a new object was shown, and the procedure was repeated. See video 2 for further details. Right: In the combined condition (right), the locations of the objects could be coded relative to the fixed viewpoint and relative to the spatial landmarks. See video 3 for further details.