TIME ACCURACY FUNCTIONS FOR DETERMINING PROCESS AND PERSON DIFFERENCES - AN APPLICATION TO COGNITIVE AGING

A paradigm for the determination of time-accuracy functions (TAFs) for individual participants is introduced for two pairs of tasks differin g in cognitive complexity, that is, word scanning vs cued recognition and figural scanning vs figural reasoning. TAFs can be used to test di ssociations of cognitive processes beyond scale-related ambiguities of ordinal interactions. The approach is applied to examine the cognitiv e-aging hypothesis that a single slowing factor can account for intera ctions between adult age and cognitive task complexity. Twenty young a nd 20 old adults participated in 17 sessions. Presentation times requi red for 75, 87.5, and 100% accuracies were determined for each task wi th a variant of the psychophysical method of limits. Accuracy was fit by negatively accelerated functions of presentation time. State-trace analyses showed that different slowing factors are required for high- and low-complexity tasks. Relations to speed-accuracy and performance- resource functions are discussed. (C) 1994 Academic Press, Inc.