AUTOMATIC SPATIAL UPDATING DURING LOCOMOTION WITHOUT VISION

People can update their spatial relationships relative to the environm ent while walking without vision. The hypothesis that such updating is automatic was tested in a locomotor task in which the subjects were a sked to refrain from updating their positions. Subjects walked without vision to one of four previously seen targets via a second location. In one condition-the updating condition-the subjects were asked to wal k to the real position of the target relative to the second location; in another-the ignoring condition-they were asked to imagine that they had not moved from the starting point and to walk from the second loc ation as if walking to the target from the initial location. When the subjects were asked to start walking to the target as soon as it was n amed by the experimenter, they performed better in the updating condit ion than in the ignoring condition. When the subjects were allowed mor e time to respond, the difference in performance between these two con ditions disappeared. The results suggest that the subjects automatical ly updated their positions as they mol ed, but that, given enough time , they could override this updating retrospectively using more deliber ate cognitive processing.