Open AccessThe Pulfrich effect and depth constancy[Note 1. This research was supported by a grant from the ...]
Author(s) -
Nakamizo Sachio,
Lei Chen
Publication year - 2000
Publication title -
japanese psychological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 30
eISSN - 1468-5884
pISSN - 0021-5368
DOI - 10.1111/1468-5884.00152
Subject(s) - stimulus (psychology) , depth perception , mathematics , binocular disparity , optics , horizontal plane , stereopsis , physics , computer vision , geodesy , psychology , communication , artificial intelligence , geometry , computer science , perception , geology , neuroscience , psychotherapist
Perceived depth of the Pulfrich effect was measured as a function of viewing distance and target velocity. The stimulus was a vertical rod, moving sinusoidally back and forth along a horizontal path 22.5 cm long, within the observer's frontoparallel plane. The two independent variables were the viewing distance (1, 2, 3, and 4 m) and the target velocity (.2, .4, and .6 Hz). Observers viewed the stimulus binocularly through a neutral‐density filter (1.0 OD) in front of the right eye and were then required to perform two tasks. The first was to adjust the position of a depth probe so that it appeared to be at the same location as the target in the center of its apparent path. The other was to reproduce the extent of the perceived depth of the target from the stimulus plane in the center of its path. The results with eight observers showed that the magnitude of the perceived depth for all target velocities in either task increased almost in proportion to the viewing distance. This result suggests that the visual system calibrates an equivalent of binocular disparity, which is assumed to be transformed from the visual latency difference in the Pulfrich effect, through the use of absolute distance information.