This title is the second part of the article “Improving Vision Among Older Adults: Behavioral Training to Improve Sight,” by DeLoss, Watanabe, and Andersen in Psychological Science Online First, March 6 2015 as dii:10.1177/0956797614567510. Age-related decline in visual function could be due to optical, retinal, cortical, or pathological changes, there also appears to be a cortical locus as a result of decreased inhibition in the visual cortex.
This study assessed whether perceptual learning could be a possible intervention to counteract age related declines in contrast sensitivity. Younger and older subjects performed an orientation-discrimination task using sine wave gratings that varied in contrast. The researchers assessed whether training improved performance for targets at a specific location, transferred to targets at an untrained orientation, and transferred to other tasks ( near- and far-acuity tasks, for example).
Sixteen younger adults (mean age=22.43) and 16 older adults (mean age=71.23) participated in the experiment. The experiment consisted of 1.5 hr per day of testing and training over 7 days. Participants were required to complete the study within 3 weeks of their first testing session.
The major finding of the study is that five days of training for older adults resulted in performance that was not statistically different from that of younger adults prior to training. Clearly perceptual learning can be used to counter age-related declines in contrast sensitivity. The authors note that a these improvements are the result of changes in sensory process and not due to the optical efficiency of the eye.
Both age groups also showed significant transfer of learning to an untrained orientation. Another important finding is that both younger and older individuals showed significant improvement in acuity with perceptual-learning training. These improvements in acuity were associated with the range of acuity most problematic for each age group. Younger individuals showed an improvement in far acuity, whereas older individuals showed improvement in near acuity. These improvements were substantial resulting in an average of from two to three additional letters on the acuity charts after training. So the benefits of this training is not restricted to older adults.
This research provides strong evidence of the plasticity of visual processing as we age. Further research is needed to determine how much more improvement could be gained by additional training. Let us hope that such research will be done expeditiously and that programs will be developed for dissemination to the general population..