Abstract
Several studies have suggested that various aspects of motion perception decline with age. Amongst those highlighted are motion coherence thresholds. In this study we extend previous findings by (1) measuring coherence thresholds across a wide range of speeds and (2) relate the findings to changes in earlier visual processing as indexed by contrast sensitivity to grating patterns over a wide range of spatial and temporal frequencies. Standard two-option forced-choice techniques were used to measure motion coherence thresholds for random dot patterns at four speeds covering a sixteen-fold range, and contrast sensitivity to gratings at three spatial frequencies and three temporal frequencies. In agreement with previous findings we find that coherence thresholds decline with age for slow movements, however contrary to previous findings we find no loss of performance for a range of medium to fast motions. Such results are inconsistent with theories of selective loss of M-cell function in old age.