Purchase this article with an account.
J. B. Wilmer, B. T. Backus; Genetic Contribution to Individual Differences in Depth Judgement From Binocular Disparity. Invest. Ophthalmol. Vis. Sci. 2007;48(13):5884.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
One in three individuals is essentially blind to some range of stereoscopic depth for briefly presented stimuli (Richards, 1970). What are the relative contributions of genes and environment to these individual differences?
The degree to which identical twins (100% genetically similar) are more similar for a given trait than fraternal twins (50% genetically similar) indicates the heritability of that trait. We used a recently developed stereo test of perceived depth by van Ee & Richards (2002) to test 90 identical and 20 fraternal twin pairs on a range of binocular disparities (13 levels from 2 deg crossed to 2 deg uncrossed) and at two durations (.2 or 1.5 sec). We computed the precision of each individual's depth judgements for near and far disparities, and for long and short durations.
Identical twins' depth estimation precision was more similar than fraternal twins' across the disparities and durations tested, suggesting heritability. This difference reached statistical significance (p=0.01) for the uncrossed, long duration stimuli, so performance over this spatial and temporal range may be particularly heritable. However, performance was generally poorer for crossed and short duration stimuli, so future testing may reveal heritability at other depths and display durations.
Our results suggest that one's ability to precisely determine depth from binocular disparity is heritable, at least for some spatial and temporal ranges, and they provide the first step toward identifying clinically significant genes that influence depth perception.Richards W. (1970) Stereopsis and stereoblindness. Exp Br Res, 10, 380-8.van Ee R., Richards W. (2002) A planar and a volumetric test for stereoanomaly. Perception, 31, 51-64.
This PDF is available to Subscribers Only