Aging on the input versus output side: Theoretical implications of age-linked asymmetries between detecting versus retrieving orthographic information

This experiment tested for age-linked asymmetries predicted under Node Structure theory (NST; D. G. MacKay & D. M. Burke, 1990) between detecting versus retrieving orthographic information. Older adults detected that briefly presented words were correctly spelled (e.g., endeavor) or misspelled (e.g., endeavuor) as readily as did young adults. However, they were less able than young adults to retrieve the correctly and incorrectly spelled words that they had seen. These age-linked asymmetries were not due to educational factors, stimulus characteristics, sensory-level factors, task complexity, floor or ceiling effects, general slowing, or cohort-related activities, but they were consistent with NST predictions and with similar asymmetries in a wide range of other studies. By contrast, repetition deficits in detecting and retrieving repeated- versus unrepeated-letter misspellings (e.g., elderdly vs. elderkly) were symmetrical or equivalent in magnitude for young and older adults. Implications for a wide range of theories of cognitive aging and of repetition deficits are discussed. In this article we report the first systematic comparison of aging effects on the input versus output side of language processing. The input side of language involves perception of the letters and speech sounds that make up words as well as comprehension of the meanin