ABSTRACT
The results from several meta-analyses place new constraints on the general slowing hypothesis of age-related changes in the rate of cognitive processing. It was found that in the lexical domain, a linear function described the relationship between the response latencies of older (age 65 – 75) and younger (age 19 – 29) adults with great precision: O= 1.48 Y − .067, where O and Y refer to older and younger latency, respectively, and the unit is the second; adjusted r 2 = .976. This function was based on data from lexical decision experiments and accurately predicted performance in an independent set of experiments employing other lexical tasks. In contrast, performance in nonlexical tasks spanning the same range of task difficulty was described by a nonlinear, positively accelerated power function: O = 1.60 Y1.26, adjusted r 2 = .951. It was concluded that although general slowing is observed in both the lexical and the nonlexical domains, latencies in the former are consistently shorter than would be predicted based on performance in the latter. These results are interpreted within the framework of the Information Loss Model, a mathematical model of age-related cognitive slowing (Myerson, Hale, Wagstaff, Poon, & Smith, in press).
