Age-related differences in temporal processing

Visual backward masking paradigm, as determined with the shine-through effect, is a very sensitive tool to detect age related differences in visual temporal processing. We presented a vernier offset to the left or right followed by a grating mask which impedes vernier offset discrimination. Because of the use of such a vernier acuity task, visual deficits are unlikely caused by optical deficiencies. In the first experiment, we found strongly deteriorated masking performance of elderly from 60 years on and teenagers basically from 7 to 13 years compared to controls aged between 18 and 32 years. In a second experiment, we varied the spatial and temporal layout of the mask, for example, by inserting a small gap in the grating mask. With these manipulations, processing deficits in elderly turned out to be very different from the teenagers' ones. Teenagers were sensitive to the gaps (and other manipulations) whereas elderly were not--possibly because elderly low-pass filter visual information, such as the gaps, related to a loss of retinal and other neurons.