Lexico-semantic access and audiovisual integration in the aging brain: Insights from mixed-effects regression analyses of event-related potentials

Available online 16 December 2021 We investigated how aging modulates lexico-semantic processes in the visual (seeing written items), auditory (hearing spoken items) and audiovisual (seeing written items while hearing congruent spoken items) modalities. Participants were young and older adults who performed a delayed lexical decision task (LDT) presented in blocks of visual, auditory, and audiovisual stimuli. Event-related potentials (ERPs) revealed differences between young and older adults despite older adults’ ability to identify words and pseudowords as accurately as young adults. The observed differences included more focalized lexico-semantic access in the N400 time window in older relative to young adults, stronger re-instantiation and/or more widespread activity of the lexicality effect at the time of responding, and stronger multimodal integration for older relative to young adults. Our results offer new insights into how functional neural differences in older adults can result in efficient access to lexico-semantic representations across the lifespan. This work was supported by a Marie Curie Individual Fellowship 702178 by the European Commission and a Juan de la Cierva Formacion Fellowship FJCI-2017-31782 from the Spanish Ministry of Science, Innovation and Universities to RALZ, NWO VENI grant 275-89-027 to MB, MINECO grant PSI 2017-82563-P from the Spanish Ministry of Economics and Competitiveness to AGS, Natural Sciences and Engineering Research Council of Canada Discovery Grant 502584 to BCA, and by the Basque Government through the BERC 2018–2021 program.