Abstract

Considerable research has been devoted to measurements of contrast threshold in older adults. These studies have revealed significant differences between young and older observers in contrast sensitivity at high spatial frequencies. Normal age-related changes in suprathreshold contrast perception have also been reported. With a contrast discrimination paradigm, it has been found that the facilitation effect commonly reported at 0.008 standard contrast level in young observers is not present for older participants. The current investigation tested whether a facilitation in contrast discrimination ability for older adults is totally absent or is merely shifted to a higher contrast level. The subjects were 10 young and 10 older individuals. All observers had corrected visual acuity of at least 20/20 for the test distance and revealed no signs of visual pathology. Results indicate that the facilitation effect is entirely absent in this sample of older observers. The results are discussed in terms of existing theories of the facilitation effect, incorporating the effects of added noise and slower temporal processing in the visual systems of older adults.

© 1990 Optical Society of America