The Effects Of Age And Verbal Ability On Word Predictability In Reading

Increased predictability effects in older compared to younger adults have been mostly observed in late eye-movement measures during reading. However, it is unclear whether and how these effects may be related to verbal ability, which typically improves with age. Past studies have shown that verbal abilities modulate the predictability effect. Here, we aimed to replicate predictability effects in younger and older adults in a sentence reading paradigm and to investigate how verbal ability modulates the predictability effect. We monitored 26 younger and 27 older adults' eye movements as they read sentences with target words varying in predictability and examined the impact of age and verbal ability, as reflected in vocabulary and print exposure measures. Replicating previous studies, we found that older adults relied more heavily on contextual information in their anticipation of upcoming input in one late measure. In one early measure (first-fixation duration), participants with higher scores in verbal ability showed greater predictability effects, whereas the predictability effect was virtually absent in those with low scores. In one late measure (regression-path duration), age interacted with predictability. However, verbal ability, when included as a covariate in this model, could not account for the age-related increases in predictability effects. Collectively, our findings indicate that verbal ability influences predictability effects in early processing stages, suggesting facilitation of initial word processing and that some aspect of aging other than verbal ability influences predictability effects in late measures. The latter finding most likely reflects a shift toward integrative controlled processes with age.