The effect of age on the speed of sentence formation and incidental learning.

To test the hypothesis that older persons tend not to use verbal mediators in paired-associate learning because it takes them too long to form an appropriate mediator, the time needed by young and old subjects to generate sentences incorporating given pairs of nouns was measured. Older subjects formed sentences just as rapidly as did the young. Despite their equivalent speed in creating these verbal associations when tested later for the occurrence of incidental learning of the noun pairs, the older subjects showed much poorer recall than did the younger subjects. This age difference in learning did not appear to be a function of any major dissimilarities in the generated sentences themselves, i.e., in the grammatical constructions used, or in the imageability of the relationships expressed by the sentences. The rated imagery value of the stimulus nouns was found to affect both the speed of sentence formation and the accuracy of incidental learning; in both younger and older subjects, formation time was less, and recall was better for the high imagery noun pairs.