Further Experiments on the Effects of Foveal Load on Peripheral Vision

Abstract

The main objective of this research was to investigate the effects of foveal load on sensitivity in the peripheral visual field. The first experiment was presented at previous meeting of the Human Factors Society. Here, foveal load was manipulated by comparing the fixation of a cross vs. a simple first-order compensatory tracking task display. Peripheral sensitivity was determined simultaneously for light flashes presented at different eccentricities along the horizontal meridian. In general, the results showed no losses in peripheral sensitivity or a “tunnel vision” effect under the experimental conditions employed. Three more experiments have been carried out since that presentation. More complex tracking tasks have been employed in order to vary foveal load and the difficulty of the perimetry task has also been manipulated in one experiment by including lights on the vertical meridian. Whether or not a loss or a gain in peripheral sensitivity depends upon the complexity of the foveal task and to some extent the perimetry task. Results are discussed in terms of arousal and resource theory.