The impact of memory on age differences in digit symbol performance.

The roles of memory and unnecessary reliance on the coding key were examined in relation to age differences in performance on the WAIS Digit Symbol test. Old and young adults were trained to a stringent criterion of learning the digit-symbol pairings before carrying out the task. Their performances on the Digit Symbol test were then compared to performances of control subjects who had not learned the digit-symbol pairs. Memory training had no effect on the performances of older adults; it did benefit slightly the performances of younger persons. Unnecessary reliance on the coding key was examined by allowing the use of the Digit Symbol key, even when it was not needed. There were no significant differences between the performances of either old or young adults who had the key as compared to those who did not. It was concluded that neither memory nor unnecessary reliance on the coding key explain the difficulties older adults experience in performing digit-symbol substitutions.