Y. Zhang and P.H. Schiller, 2004
Soc
Neurosci. Abstr., 865.11
Abstract
The three-dimensional world we perceive is derived from two-dimensional retinal
images. One of the most powerful cues for depth perception is motion parallax
(MP): the differential motion on the retinal surface determined by the 3-D geometry,
the movement of the visual objects, the movement of the viewer, and the distance
between the two.
To study depth perception created by MP in the head-fixed rhesus monkey, we
devised a novel display: a single flat rocking surface formed by random dots.
When a set of dots within the display is moved at a higher velocity than the
background, this set is perceived as protruding in depth. The extent of the
protrusion (the depth) is represented by the degree of relative movement between
the object and the background; the movement of the viewer is simulated by the
rocking motion of the entire display.
To determine how the depth perceived depends on the relative movement between
the objects and the background as well as the overall motion of the entire display,
we used both detection and discrimination tasks. The animals task was to detect
a protruding single square-shaped surface at one of four possible locations,
or to discriminate the one, out of four, at a greater depth.
Two monkeys were studied. We recorded both the % correct responses and the reaction
times (RTs). For both detection and discrimination tasks, the % correct performance
decreased and RTs increased as the extent of target protrusion was reduced.
Increasing the speed of the overall movement of the visual scene improved performance.
In general, % correct performance was higher and RTs were faster in the detection
task than in the discrimination task.
Our results show that depth perception based on MP is determined by both relative
movement between objects and the overall motion of the visual scene. Our results
also suggest that motion-parallax induced depth perception may be processed
in a hierarchic fashion in the visual system.
Support Contributed By: NIH grants F32-EY014750, R01-EY08502.
Citation: Y. Zhang, P.H. Schiller. BEHAVIORAL ASSESSMENT OF DEPTH PERCEPTION BASED ON MOTION PARALLAX IN THE NON-HUMAN PRIMATE Program No. 865.11. 2004 Abstract Viewer/Itinerary Planner. Washington, DC: Society for Neuroscience, 2004. Online.