Abstract:

PURPOSE: Given the well documented age-related declines in contrast sensitivity (CS) and that CS is a contributing factor to age-related increases in driving accident risk, the current study aims to answer an important question that whether one can at least partially reverse age-related CS deficits for older adults through perceptual learning (PL) training.
METHODS: A total of 32 older adults (Mean age = 77.86, SD = 9.41) were randomly assigned to two training group, either being training with a contrast discrimination (CD) task or being trained with an orientation discrimination task (ORD). Participants were measured on their CS and ORD performance before and after two days’ PL training.
RESULTS: Participants in both groups showed significant improvements on their training tasks for the trained eye. More importantly, signi?cant transfer e?ects across tasks were found for both groups (e.g. from ORD to CD, and from CD to ORD), but not for an active control group in which participants received training on multiple object tracking. Signi?cant transfer was also found for untrained eyes, but not for untrained orientations.
CONCLUSIONS: These results showed that older individuals could improve their CS through training. Such improvements were obtained even in untrained eyes and tasks as long as the training displays were similar to the test displays. Thus, given the orientation-speci?city found in this study, the results support the idea that PL of CD and ORD results from a low level in the visual pathway (i.e., V1), in which both tasks share the same mechanism at that representational level.

Key words: perceptual learning, transfer, aging, contrast sensitivity