Sounds, Words, Sentences: Age-related changes across levels of language processing
Federmeier, Van Petten, Schwartz, & Kutas
Age-related changes in sensory, lexical, and sentence processing were examined and compared using event-related potentials (ERPs) recorded as young (mean age 22) and elderly (mean age 72) participants listened to natural speech for comprehension. Stimuli consisted of lexically associated and unassociated word pairs embedded in meaningful or syntactically legal but meaningless sentences. Early sensory and attention-related responses were delayed by ~25 ms for the elderly, but later components (e.g., N400) were not delayed. There were no differences in the size, timing, or distribution of lexical associative effects for the two groups. In contrast, message-level context effects were delayed more than 200 ms in the elderly group. The results support models that posit age-related changes primarily in higher-order language processes.