Binocular detection of masked patterns in young and old observers.

A visual pattern embedded in noise is detected appreciably better when the stimulus complex contains interocular cues (dichoptic condition) than when such cues are absent (binoptic condition). In a recent study (F. Speranza, G. Moraglia, & B. A. Schneider, 1995) the authors showed that the relative difference between binoptic and dichoptic thresholds does not change with age. However, older adults showed higher binoptic and dichoptic thresholds, thus suggesting an age-related difficulty with degraded stimulation. In this article the authors first replicated these findings and proceeded next to investigating whether age-related changes in processing efficiency, additive internal noise, and the spatial frequency bandwidth of the detecting filters could account, separately or concurrently, for the elevated thresholds in noise exhibited by the older adults. Results indicate that this increase is not attributable to age-related changes in filter bandwidth or internal noise. Rather, the findings can be explained in terms of a decrease in processing efficiency with age.