Aging and memory for numerical information: the role of specificity and expertise in associative memory.

In order to examine the nature of associative memory deficits in old age, the present study examined how younger and older adults link numerical and object information to other items. The hypothesis was that there would be large age differences for numerical information caused by the arbitrariness and specificity of this type of information, but that this could be reduced by expertise. Participants studied sentences that contained numeric quantity, object, and location information (e.g., 26 cherries in the bowl); they were later cued with the location and had to recall the object and quantity. In general, there were significant age differences for quantity recall but negligible age differences for recall of related objects but not unrelated objects. However, a group of older retired accountants and bookkeepers showed exceptional memory for quantity information. The findings suggest that the associative deficit in old age is based on the linking of specific arbitrary information.