The time course of word recognition in younger and older adults: Signal degradation and lexical challenge

Abstract

As listeners age, speech recognition often becomes more challenging, especially in noisy environments. Older adults also appear to have more difficulty resolving lexical competition than do younger adults. Relatively little is known, however, about how such signal- and lexicon-related challenges interact to affect the timing of word recognition and how such effects might change across the lifespan. In this study, we use a visual world paradigm to investigate the effects noise, word frequency, and phonological neighborhood density on the time course of spoken word recognition in young and older adults. On each trial, listeners saw four items on a computer screen and heard “Click on the” followed by a target word that corresponded to one of the images. None of the other items on the display were phonologically or semantically related to the target. Eye-tracking results show that the time course of word recognition is predicted by age, noise, frequency, density, and several of their interactions. In general, high-frequency words and words from dense phonological neighborhoods were fixated more quickly, while noise and age slowed recognition. These results support a framework in which lexical and acoustic factors co-determine the cognitive challenges associated with speech perception.As listeners age, speech recognition often becomes more challenging, especially in noisy environments. Older adults also appear to have more difficulty resolving lexical competition than do younger adults. Relatively little is known, however, about how such signal- and lexicon-related challenges interact to affect the timing of word recognition and how such effects might change across the lifespan. In this study, we use a visual world paradigm to investigate the effects noise, word frequency, and phonological neighborhood density on the time course of spoken word recognition in young and older adults. On each trial, listeners saw four items on a computer screen and heard “Click on the” followed by a target word that corresponded to one of the images. None of the other items on the display were phonologically or semantically related to the target. Eye-tracking results show that the time course of word recognition is predicted by age, noise, frequency, density, and several of their interactions. In general,...