The effects of aging on spatial frequency tuning

Purpose. To examine whether spatial frequency channels change with age. Method. Detection thresholds were measured for a 4 c/deg sinewave grating embedded in high- or low-pass noise. Masked thresholds were used to derive estimates of the shape and bandwidth of spatial frequency filters in six older (mean age 60) and six younger observers (mean age 23). Results. The group and individual data provide converging evidence that the low-frequency, but not the high-frequency, side of the spatial frequency filter becomes more broadly tuned with age. Conclusions. There are two interpretations of these results: 1) The spatial frequency filters of older observers are broader than those of younger observers; 2) The observed change in filter shape results from younger observers employing an off-frequency looking strategy to a greater extent than older observers. We will report results from recent experiments that support this second interpretation.