Nonvisually Guided Locomotion to a Previously Viewed Target in Real and Virtual Environments

Comparing human performance in a virtual environment (VE) with performance in the real world can provide clues about which aspects of VE technology require improvement. Using a technique previously shown to measure real-world distance judgments accurately, we compared performance in a real-world environment with performance in a virtual model of that environment. The technique required participants to walk without vision to a target after viewing it for 10 s. VE distance judgments averaged 85% of the target distance, whereas real-world judgments averaged 92%. The magnitude of the relative errors in the VE was twice that in the real world, indicating that the VE degraded distance judgments. Our analysis suggests that VE performance deficits result either from poor binocular disparity cues or from distortion of pictorial depth cues. Actual or potential applications of this research include the development of virtual environments for training and the design of visual displays for virtual simulations.