Abstract

The technique of spatial scaling provides a method by which the rate of decline in performance in any psychophysical task can be determined as a function of eccentricity. The main advantage of the technique is that no prior assumptions regarding the size of peripherally presented stimuli need to be made. We measured thresholds for discriminating the direction of movement of an object that underwent an instantaneous displacement either to the right or left. No stationary references were present in the rest of the visual field. The rate at which performance changes with eccentricity is conveniently denoted by E₂ which represents the eccentricity at which foveal stimulus size must double to maintain equivalent performance.

© 1991 Optical Society of America