First- and second-order processing in transient stereopsis.
Large-field stimuli were used to investigate the interaction of first- and second-order pathways in transient-stereo processing. Stimuli consisted of sinewave modulations in either the mean luminance (first-order stimulus) or the contrast (second-order stimulus) of a dynamic-random-dot field. The main results of the present study are that: (1) Depth could be extracted with both the first-order and second-order stimuli; (2) Depth could be extracted from dichoptically mixed first- and second-order stimuli, however, the same stimuli, when presented as a motion sequence, did not result in a motion percept. Based upon these findings we conclude that the transient-stereo system processes both first- and second-order signals, and that these two signals are pooled prior to the extraction of transient depth. This finding of interaction between first- and second-order stereoscopic processing is different from the independence that has been found with the motion system.
Edwards
M
M
School of Optometry, University of California, 94720, Berkeley, CA, USA. mark@hering.berkeley.edu
Pope
D R
DR
Schor
C M
CM
D003867:Depth Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology*