Is vision metric? Comment on Lappin and Love (1992).
In a recent paper, Lappin and Love (1992) showed that depth judgments, based on planar motion of a stimulus, are remarkably precise. This led them to the conclusion that perception of planar motion allows acquiring metric information about visual space. We show, however, that Lappin and Love's stimuli contained 2-D cues in the frontal plane that could subserve the subject's judgments. This means that high precision in this task does not necessarily imply metric structure of visual space.
Purdue University, West Lafayette, Indiana.
Z
Z
Pizlo
M
M
Salach-Golyska
D003867:Depth Perception; D006801:Humans; D010775:Photic Stimulation; D015348:Vision, Binocular