Electrophysiological evidence for preserved primacy of lexical prediction in aging. (August 2018)

• Record Type: Journal Article
• Authors: Dave, Shruti; Brothers, Trevor A.; Traxler, Matthew J.; Ferreira, Fernanda; Henderson, John M.; Swaab, Tamara Y.
• Is Part Of: Neuropsychologia. Volume 117(2018)
• Page Start: 135
• Page End: 147
• Publication Date: 2018-08
• Subjects: Prediction -- Contextual Support -- Aging -- N250 -- N400 -- Post-N400 positivity -- Reading; Neuropsychology -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Neuropsychologie -- Périodiques; Neuropsychology; Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.neuropsychologia.2018.05.023
• Languages: English
• ISSNs: 0028-3932

Abstract

Abstract: Young adults show consistent neural benefits of predictable contexts when processing upcoming words, but these benefits are less clear-cut in older adults. Here we disentangle the neural correlates of prediction accuracy and contextual support during word processing, in order to test current theories that suggest that neural mechanisms underlying predictive processing are specifically impaired in older adults. During a sentence comprehension task, older and younger readers were asked to predict passage-final words and report the accuracy of these predictions. Age-related reductions were observed for N250 and N400 effects of prediction accuracy, as well as for N400 effects of contextual support independent of prediction accuracy. Furthermore, temporal primacy of predictive processing (i.e., earlier facilitation for successful predictions) was preserved across the lifespan, suggesting that predictive mechanisms are unlikely to be uniquely impaired in older adults. In addition, older adults showed prediction effects on frontal post-N400 positivities (PNPs) that were similar in amplitude to PNPs in young adults. Previous research has shown correlations between verbal fluency and lexical prediction in older adult readers, suggesting that the production system may be linked to capacity for lexical prediction, especially in aging. The current study suggests that verbal fluency modulates PNP effects of contextual support, but not prediction accuracy. Taken together, our findings suggest that aging does not result in specific declines in lexical prediction. Highlights: Neural facilitation for accurate predictions slowed and reduced in older adults. Similar age-related changes emerge for facilitation via contextual support. Time course of predictive benefits preceding context effects is maintained in aging. Updating following unpredicted or unsupported words is intact in older readers. Prediction during comprehension is not selectively impaired in older readers.