Adult age effects of plausibility on memory: the role of time constraints during encoding

We investigated the role of training-induced knowledge schemas and encoding time on adult age differences in recall. High-plausible (schema coherent) words were recalled better than low-plausible (schema discrepant) words in both age groups. This difference was larger for old adults than for young adults for presentation times ranging from 3 s to 11 s per word. After equating participants in overall recall (i.e., at 50% correct) by dynamic adjustment of presentation time, old adults again showed a stronger plausibility effect than young adults when recall was above criterion. In a second experiment with self-paced encoding, old adults used more time than young adults only for low-plausible pairs, yet they still remembered fewer of them. In a third experiment, both age groups preferred to imagine high- rather than low-plausible words, but this effect was more pronounced in old adults. The results indicate that, compared with young adults, old adults find it particularly difficult to form elaborative mental images of schema-discrepant information under a wide variety of time constraints during encoding. Results are discussed in relation to explanations based on age-related mental slowing.