Journal article

Achromatic impulses unmask L- and M-cone adaptive mechanisms

AJ Zele, AJ Vingrys

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY | BLACKWELL SCIENCE ASIA | Published : 2001

Abstract

The mechanisms underlying the adaptive response for achromatic impulses seen on achromatic fields were investigated. Foveal thresholds were measured for a static probe-impulse under two conditions of adaptation. Thresholds were obtained under gain-clamped conditions after observers had reached steady-state adaptation and with a probe-flash paradigm. It was found that thresholds isolated on steady-state fields cannot be modelled using a single mechanism. Likewise, the probe-flash condition failed to reflect the response of a single mechanism. Both threshold functions showed distinct breaks occurring at about the same field luminance (approximately 1.0 log cd/m2). Optimum data fits required th..

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