The expanding telephone number Part 2: Age variations in immediate memory for multiple-digit numbers
Immediate ordered recall of multiple-digit numbers was investigated in a practical read-and-key or listenand-key task for three age groups whose mean ages were 25.2 years (range 23–27), 44.1 years (range 42–44) and 63.6 years (range 61–68), all recruited from students and faculty staff at the University of Oslo. The two younger groups performed at comparable levels on the immediate memory task, surpassing the performance of the older group for both visual and auditory presentation of the digit-strings. Increasing the presentation time of the numbers affected the young and older age groups similarly by improving the memory performance. Analyses of the serial position curves revealed an enhancement of the well-known modality effect in the older subjects. The overall decline in memory performance observed at the age of 65 should be taken into account in design of communication technology for the general public.