Spatial updating of environments described in texts.

People update egocentric spatial relations in an effortless and on-line manner when they move in the environment, but not when they only imagine themselves moving. In contrast to previous studies, the present experiments examined egocentric updating with spatial scenes that were encoded linguistically instead of perceived directly. Experiment 1 demonstrated that, regardless of the mode of rotation (physical or imagined), egocentric updating takes place in a deliberate and backward fashion when the locations of objects are anchored in a mental framework. Experiment 2 involved only imagined rotations and showed that results remained unchanged when spatial labels were removed from the scene descriptions. Experiment 3 provided evidence that physical rotations--but not imagined rotations--lead to on-line updating of egocentric relations, provided that the objects of the scene are represented in a sensorimotor framework. The present results suggest that physical movements and sensorimotor encoding are both prerequisites of effortless egocentric updating.