Threshold and suprathreshold spatiotemporal response throughout adulthood.

The effect of age on spatiotemporal contrast sensitivity at both threshold and suprathreshold levels was studied in 63 adults ranging in age from 13 to 67 years. Sensitivity for low spatial frequencies modulated at 0 to 15 Hz was not affected by age, but a progressive age-related elevation of threshold was found for combinations of high spatial and temporal frequencies. The magnitude of the effect ascribed to age on spatial frequency was larger than the effect of age on temporal frequency. For most combinations of spatial and temporal frequencies, elevation of thresholds started at approximately 45 years of age. No age-related effects were observed in a contrast-matching task performed at suprathreshold levels.