Age-related differences in referential production: A multiple-measures study.

Contemporary research on aging has provided mixed evidence for whether older adults are less effective than younger adults at designing and delivering spoken utterances. However, most of these studies have focused on only specific aspects of this process. In addition, they tend to vary significantly in terms of the degree of complexity in their chosen stimuli or task. The present study compares younger and older adults' performance using a referential production paradigm involving simple everyday objects. We varied referential context such that a target object was either unique in its category (e.g., one shirt), or was accompanied by a same-category object (e.g., two shirts). We evaluated whether speakers' descriptions provided listeners with sufficient information for identification, and whether speakers spontaneously adapt their speech for different addressee types (younger adult, older adult, automated dialogue system). A variety of measures were included to provide a comprehensive perspective on adults' performance. Interestingly, the results revealed few or no age differences in measures related to production performance (speech onset latency, speech rate, and fluency). In contrast, consistent differences were observed for measures related to descriptive content, both in terms of informativity and variability in lexical selection: Older adults not only provided more information than necessary for referential success (e.g., superfluous modifiers), but also exhibited greater variability in their selection of modifiers. The results show that, although certain aspects of the production process are well-preserved across the adult lifespan, meaningful age-related differences can still be found in simple referential tasks with everyday objects. (PsycINFO Database Record (c) 2019 APA, all rights reserved).