THE EFFECT OF GAP DEPTH ON THE PERCEPTION OF WHETHER A GAP IS CROSSABLE

Four experiments were performed in order to examine the effect of gap depth on human observers' perception of whether-or not a gap is crossa ble. Experiments 1 and 2 showed that as the gap's depth increased, obs ervers tended to increasingly underestimate the maximum width of a gap they could step across. Experiments 3 and 4 clarified this finding: T he observed covariation of perceived gap crossability and gap depth de pended on the observer's direction of gaze, rather than on the physica l depth of the gap. The optical relations to which observers might be attending are discussed, as well as the possibility that cognitive-aff ective processes might have contributed to observers' underestimation of their actual capabilities.