Perception of collisions while walking in a virtual environment with simulated peripheral vision loss.

Abstract

While walking, people rely on visual judgments to avoid collisions. People with severe peripheral vision loss (“tunnel vision”) report frequent collisions with obstacles. We used a virtual environment to examine how normally-sighted subjects performed with and without simulated tunnel vision in a collision-detection task. The virtual environment consisted of a treadmill situated in front of a large rear-projected screen (about 95 degrees wide). Subjects walked down a simulated shopping mall corridor and were shown one-second glimpses of human-sized obstacles at eccentricities from zero to 12 degrees relative to their heading. Subjects were asked to judge whether continued walking in the same direction would have resulted in a collision with the obstacle. Head and eye tracking were used to dynamically adjust a dark mask restricting the subject's field of vision. Restrictions revealed only parts of the scene within circles 5, 10 or 20 degrees in diameter centered at the subject's center of gaze. Not surprisingly, subjects failed to see obstacles more frequently as their vision was increasingly restricted. However, when subjects were allowed to repeat obstacle presentations that they failed to see, performance at discriminating collisions was unaffected by peripheral vision restriction.

Footnotes

 Supported in part by NIH Grant EY12890.