Younger adults use both semantic and phonological cues to quickly and efficiently localize the referent during sentence comprehension. While some behavioral studies suggest that older adults use contextual information even more strongly than younger adults, ERP studies have shown that this population, as a group, is less apt at using contextual semantic cues to predict upcoming words. The current study extends the investigation of contextual cue processing in auditory sentence comprehension beyond semantic cue processing, by comparing younger and older adults in their ability to use phonological cues in indefinite articles (a/an) to localize the referent in an eye-tracking visual world paradigm. Our results suggest that both age groups use such phonological information for referent localization, but with different timelines: younger adults use the cues to anticipate an upcoming word, whereas older adults show delayed cue processing after the target word has been spoken. Together with findings from semantic context processing, these results support a model of sentence comprehension in which the use of contextual cues continues with aging, but is no longer as efficient as in the young system for anticipatory word retrieval.

Speech production in aphasia is often described as “effortful”, though the consequences of consistent, high degrees of cognitive effort have not been explored. Using recent work on mental effort as a theoretical framework, the present study examined how effort-related fatigue produces decrements in performance in picture naming among participants with post-stroke aphasia. We analyzed three data sets from prior studies where participants completed a large picture naming test. Decreasing naming accuracy across trials was statistically significant in two of the three samples. There were also significant effects of practice (better performance on a second test administration), word frequency (better performance for more frequent words), and word length (better performance for shorter words). These results are the first concrete demonstration of fatigue affecting performance on a language task in post-stroke aphasia. They open a new avenue for research on mental effort/fatigue with potential implications for aphasia assessment, treatment, and management.