P. H. Schiller and D. Senna, 2007
Soc Neurosci. Abstr., 716.12.
Abstract
A series of tests was devised to assess stereopsis, motion parallax, binocular
integration and hand-eye coordination in intact, stereo blind and stereo impaired
subjects. In the first set of tests the ability to process depth information
based on disparity and motion parallax cues was determined. The display, viewed
through a stereoscope, consisted of a random dot array rocked back and forth
along a central, vertical axis mimicking the rocking of a solid, three dimensional
object. Disparity and motion parallax depth cues for a target appearing in one
of four locations could be presented separately or in concert. Subjects unable
to perform the task when only disparity cues were provided were considered stereo
blind as also confirmed by other tests and their history. Of the more than 120
subjects tested, 25 proved to be either stereo blind or stereo deficient.
In the second set of tests binocular integration was assessed using numbers,
words and images of stepped, rotating wheels which were presented binocularly,
monocularly and interocularly under brief exposure conditions. Virtually all
subjects with stereoscopic vision showed high levels of binocular integration.
The majority of the stereo blind subjects showed significant deficits in binocular
integration.
In the third set of tests hand-eye coordination was assessed using two procedures.
The first was a "thread-the-needle" test in which the task was to
hang fine rods with eyelets of different diameters onto a horizontal pin. Procedure
two consisted of a horizontally placed touch panel on which a series of small
black spot appeared in succession in various locations. The subjects' task was
to touch each spot with their forefingers. Testing was carried out under both
monocular and binocular viewing conditions. The time and accuracy difference
between monocular and binocular performance was significantly smaller for stereo
blind subjects than for subjects with stereoscopic vision demonstrating that
stereopsis plays a significant role in the execution of these tasks.
Our results suggest that this battery of tests can be effectively used to asses
stereopsis and motion parallax, binocular integration and hand-eye coordination
in human subjects. The tests may be especially useful for the assessment of
rehabilitative procedures for patients in whom binocular vision was acutely
compromised by injury.
Support Contributed by: NIH Grant EY014884
Citation: P. H. Schiller
and D. Senna. Depth perception, binocular integration and hand-eye coordination
in intact and stereo impaired subjects. Program No. 716.12. 2007 Neuroscience
Meeting Planner. San Diego, CA: Society for Neuroscience, 2007. Online.