Adult age differences in integrative spatial ability.

Young and older adults were contrasted in three experiments that involved manipulation of the number of required spatial integration operations (Experiments 1 and 2) and manipulation of the amount of information per operation (Experiment 3). Older adults performed at lower levels of accuracy than did young adults in each experiment. However, the magnitude of the age differences tended to increase with each successive integration operation but was constant across different quantities of relevant information. I interpreted these results as suggesting that one factor responsible for age differences in tests of spatial ability is an age-related reduction in the efficiency of executing operations responsible for the accurate and stable representation of spatial information.