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Comparison of the time courses of concomitant and nonconcomitant vertical phoria adaptation

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Vertical phoria adaptation was measured before, during, and after 1 h of training with either a prism or magnifying lens. With the prism (concomitant adaptation) a single vertical disparity was presented at primary position. With the magnifier (nonconcomitant adaptation) two vertical disparities of opposite sign were presented along the vertical meridian. Following adaptation, binocular vision was prevented with an eye patch, and vertical phorias were measured periodically along the primary vertical meridian over the course of 8 h. Despite individual variation, adaptation followed approximately exponential time courses. The average time constants for the decay of concomitant and nonconcomitant adaptation were 31 and 83 min, respectively. There was no consistent relationship between the rates of acquisition and decay nor was there a strong relationship between the gains of the adaptive responses and the rates of decay although there was a general trend for the gains of the nonconcomitant responses to be higher and the rate of decay slower than the concomitant responses. The results support the notion that concomitant and nonconcomitant phoria adaptation involve different mechanisms but not the contention that adaptation to prisms is easier or more robust than adaptation to lenses.

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Graf, Erich W., Maxwell, James S. and Schor, Clifton M. (2003) Comparison of the time courses of concomitant and nonconcomitant vertical phoria adaptation Vision Research, 43, (5), pp. 567-576. (doi:10.1016/S0042-6989(02)00597-7).

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Published date: 2003
Keywords: vergence, prism adaptation


Local EPrints ID: 18305
ISSN: 0042-6989
PURE UUID: 7b1f3090-9526-4f93-bc3e-6458e53efe41
ORCID for Erich W. Graf: ORCID iD

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Date deposited: 17 Jan 2006
Last modified: 17 Jul 2017 16:36

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Author: Erich W. Graf ORCID iD
Author: James S. Maxwell
Author: Clifton M. Schor

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