Abstract
Prior studies have consistently found that human observers exhibit visual compression, such that distances in depth (along an observer's line of sight) appear shorter than they really are (Loomis, Da Silva, Fujita, & Fukusima, 1992; Norman, Crabtree, Clayton, & Norman, 2005; Norman, Todd, Perotti, & Tittle, 1996; Wagner, 1985). In contrast, Bian and Andersen (2013) found that older adults (but not younger adults) could estimate egocentric distances (up to 12 meters) accurately. The purpose of the current study was to investigate whether this superiority of performance for older adults extends to distances greater than 12 meters. The current experiment used Gilinsky's method (1951) of creating equal-appearing intervals in depth. On any given trial, participants first viewed an orange traffic cone placed at an egocentric distance of 6m. They were then required to place five additional traffic cones (one by one) along their line of sight so that each subsequent cone appeared to be an additional 6m farther away (for accurate performance, the last cone should be placed 36m away from the participant). Twenty-one younger and older adults participated in the current study. An analysis of the results revealed a significant effect of increasing distance upon error magnitude [F(4,68) = 40.5, p < 0.000001], but there was no significant main effect of age [F(1,17) = 0.01, p = 0.91]. The current results therefore suggest that the previously obtained superiority in performance for older adults may not necessarily extend to large environmental distances.