Adult age differences in short-term memory for serial order: Data and a model

Age-related deficits in short-term memory have been widely reported, but re duced overall scores could reflect increased order errors, increased omissi ons, or increased intrusions. Different explanations for reduced short-term memory with aging lead to different predictions. Zn this study, young (n = 68; M age = 20 years) and older(n = 99; M age = 65 years) adults were pres ented with lists of letters and were asked to recall each list immediately in the correct order. Age differences in error patterns were similar for au ditory and visual presentation. For example, older adults made more errors of every type, and a greater proportion of the older adults' errors were om issions. An additional condition, in which older adults were encouraged to guess, ruled out an age increase in response threshold as a full explanatio n for the results. The data were modeled by an oscillator-based computation al model of memory for serial order. A good fit to the aging data was achie ved by simultaneously altering two parameters that were interpreted as corr esponding to frontal decline and response slowing.