Abstract

Previous research has shown that older observers have reduced contrast sensitivity at high spatial frequencies (e.g., Owsley et al., 1983). The present investigation extends this finding to include age-related changes in suprathreshold contrast perception. Contrast increment threshold functions were obtained for young (<40-years), middle aged (40-60-years) and older (>60-years) adults. A two-alternative forced-choice procedure was used to determine psychometric functions for contrast detection and discrimination of antisymmetric Gabor stimuli with a fundamental spatial frequency of 10.0 cpd. Thresholds were measured at three standard contrasts (0.0, 0.008, and 0.30) and at two levels of mean luminance (50 and 12.5 cd/m²). The results from all age groups show decreased contrast thresholds at the higher mean luminance level. Young and middle-aged observers showed the characteristic facilitation effect at the intermediate contrast. However, there was no evidence for this facilitation effect in the older age group.

© 1989 Optical Society of America