Pay now or pay later: aging and the role of boundary salience in self-regulation of conceptual integration in sentence processing.

Previous research has suggested that older readers may self-regulate input during reading differently from the way younger readers do, so as to accommodate age-graded change in processing capacity. For example, older adults may pause more frequently for conceptual integration. Presumably, such an allocation policy would enable older readers to manage the cognitive demands of constructing a semantic representation of the text by off-loading the products of intermediate computations to long-term memory, thus decreasing memory demands as conceptual load increases. This was explicitly tested in 2 experiments measuring word-by-word reading time for sentences in which boundary salience was manipulated but in which semantic content was controlled. With both a computer-based moving-window paradigm that permits only forward eye movements, and an eye-tracking paradigm that allows measurement of regressive eye movements, we found evidence for the proposed tradeoff between early and late wrap-up. Across the 2 experiments, age groups were more similar than different in regulating processing time. However, older adults showed evidence of exaggerated early wrap-up in both experiments. These data are consistent with the notion that readers opportunistically regulate effort and that older readers can use this to good advantage to maintain comprehension.