Hyphens for disambiguating phrases: Effectiveness for young and older adults

The purpose of this study was to investigate whether hyphens that disambiguate phrasing in ambiguous sentences influence reading rate and reading comprehension for younger and older adults. Moreover, as working memory (WM) has been implicated in age-related changes in sentence comprehension for both auditory and written materials, we asked if it contributed to comprehension of our sentences with hyphenated and non-hyphenated ambiguous noun phrases (NPs), predicting that the hyphens would reduce WM load. Twenty younger (M = 24 years) and 20 older (M = 73 years) adults read sentences with either ambiguous or non-ambiguous NPs that were either hyphenated or not. Both reading times for the sentences and accuracy on Yes/No questions were measured. Results indicated that younger adults read sentences more rapidly than the older participants whether sentences were presented word-by-word or as complete sentences. Both younger and older adults read sentences with ambiguous hyphenated NPs faster than sentences with ambiguous non-hyphenated NPs. Yes/No question accuracy distinguished reading of the sentences with ambiguous hyphenated phrases from those with ambiguous non-hyphenated phrases for older, but not for younger adults. Regression analyses showed that age contributed to both accuracy and reading times on this task, whereas WM did not.