Effects of ageing on the rate of visual information processing: a speed-accuracy trade-off (SAT) analysis

Age related decline has been observed for a number of different types of processing speed (Salthouse, 2000), including psychophysical processing speed (the speed at which a representation of a physical stimulus can be formed). Although aging influences speed-accuracy trade-off (Starns & Ratcliff, 2010), rarely have estimates of psychophysical processing speed been derived from studies using a speed-accuracy tradeoff methodology that examines the time course of task performance. In three experiments a speed-accuracy trade-off design was used that required identification of gabor patch orientation after differing amounts of stimulus exposure. Modelling speed-accuracy trade-off functions enabled estimation of the rate of visual information processing in a task with a single stimulus (Experiment 1), distracting stimuli (Experiment 2) or two stimuli with the target being post cued on stimulus offset (Experiment 3). Older adults displayed a deficit in visual information processing only when interfering items were present, suggesting difficulties with inhibiting distracting items and encoding and maintaining multiple distinct object representations.