Aging and resolution of quantifier scope effects.

Two experiments were conducted to compare young and older adults' processing of complex sentences involving quantifier scope ambiguities. Young adults were hypothesized to use a mix of syntactic processing strategies to interpret sentences such as Every actor used a prop or An actor used every prop. Older adults, particularly those with limited working memories, were hypothesized to rely on a simple pragmatic principle. Participants read the quantifier sentences and judged whether a continuation sentence "made sense." Reading times for the quantifier sentences and decision times and continuation sentence acceptability judgements were analyzed. Whereas young and older adults exhibited similar patterns of reading times for the quantifier sentences, they preferred different continuations for the Every ... a quantifier sentences. As predicted, both young adults and older adults interpreted a quantifier sentence such as An actor used every prop as referring to a single entity resulting in a preference for continuations such as The actor was on the stage. In contrast, young and older adults made different interpretations of a quantifier sentence such as Every actor used a prop; young adults preferred continuations postulating multiple entities such as The props were on the stage whereas older adults, particularly those with working memory limitations, preferred continuations with a single entity such as The prop was on the stage. These results support models of the effects of aging on language processing in which immediate syntactic analysis is not affected by aging or working memory limitations whereas postcomprehension processes are affected by aging and/or working memory limitations.