ADULT AGE-DIFFERENCES IN THE ONLINE PROCESSING OF NEW CONCEPTS IN DISCOURSE

Young university students and elderly community-dwelling volunteers re ad three short narratives word by word on a video display terminal, pa cing the text by pressing a key. With this ''moving window'' method, r eading times for each word were measured. Subjects recalled each narra tive immediately after reading. Regression analyses were used to predi ct word-by-word reading times from text features representing differen t levels of discourse processing (e.g., word length and frequency, ser ial position, new concepts introduced, and the presence of syntactic b oundaries). The effects of these features on reading time were examine d not only for young and old as a whole, but also for good and poor re callers within each age group. For many of these features, younger and older readers responded similarly to the demands of the text in alloc ating reading time. Interesting differences among these different kind s of readers revolved around how they allocated time to encode and org anize new concepts. Overall, older readers allocated less time to proc ess new concepts at all levels of discourse. Most notably, they were l ess likely to spend extra time at the ends of sentences, a site at whi ch younger readers reliably show evidence of organizational processing . Interestingly, relatively good recallers within the older group did not show any evidence of this ''wrap-up'' processing. Rather, older ad ults who showed high levels of text recall allocated more time to proc ess new concepts at minor syntactic boundaries (e.g., prepositional ph rases), suggesting that they pause more frequently to organize new inf ormation during reading.