Use of foreground and background information in visually guided locomotion.

The effects of reducing the range of spatial perception on the accuracy of visually guided locomotion were studied in two experiments. Limiting the range of perception to only near objects produces changes in the flow of stimulus detail and reduces opportunities for the appearance of an aiming point and for motion parallax. Such conditions were found to produce inferior performance compared to full vision, or to minimal background information. A defined aiming point was also found to assist control when no other background was present. The results are discussed with reference to theories of locomotor control and the design of artificial spatial sensing aids for the blind.