Category Judgments as Functions of Flash Luminance and Duration

Abstract

A method for obtaining suprathreshold, constant-response functions from category judgments was developed and illustrated by obtaining judgments for flashes of varying luminance and duration in the fovea. The contours show agreement with Bloch’s law; no Broca—Sulzer effect was obtained. A second experiment indicated that the method is sensitive to context effects. No reliable variation in the critical duration was found with changes in luminance level.