Aging and the depth of binocular rivalry suppression

Abstract

Two experiments were designed to examine the effect of aging upon the strength of binocular rivalry suppression. To initiate the onset of rivalry, orthogonally-oriented sine-wave luminance gratings were presented dichoptically to the observers' two eyes. The observers were then required to either discriminate the spatial location of a probe spot presented to the dominant or suppressed eye's view or to detect the presence or absence of the probe. The observers in the younger and older age groups exhibited typical rivalry suppression for both tasks (i.e., the probe was more difficult to detect or discriminate when presented to the suppressed eye), but the magnitude of the suppression was significantly larger in the older observers. This increased suppression that accompanies aging can be explained by a reduction in the inhibition produced by the binocular matching circuitry of the Lehky and Blake (1991) model.