Working memory and aging: Deficit or strategy differences?

Abstract

Thirty young and 30 older subjects were administered a reading comprehension test and a working memory test involving processing of acceptable and incongruous sentences with an increasing mnemonic preload. the complexity of incongruous sentences was assumed to solicit the processing component of working memory, whereas the size of the mnemonic preload was assumed to solicit its storage component. Results suggested not only reduced working memory capacity in older subjects, but also a change in their strategies relative to both the sentence processing/word recall and the speed/accuracy trade-offs: Older subjects favored sentence processing to the detriment of word recall, and a subset of them favored accuracy to the detriment of speed when the memory load was heavy. This change of strategy was reflected by the pattern of correlations between working memory measures and reading comprehension scores, in that the best comprehension scores were reached by the fastest young subjects, but by the most accurate older subjects. It is concluded that reduced working memory capacity intervenes in the age-related differences in reading comprehension, but that the main modifications concern the strategies used to cope with the conflictual requirements of the task.