The association between age and the frequency of nouns selected for production

This article examines whether age-related difficulties in word retrieval are reflected in the lexical frequency of the nouns selected for production. Participants (N = 136; age range 20-85 years) completed a picture-naming test, a semantic fluency task, and a picture description task. Each noun in the speech samples was examined for its lexical frequency according to published word counts and was rated subjectively by 40 young and 40 older adults. In addition, the cumulative occurrence of each noun was calculated across all descriptions. Cumulative analysis was conducted on fluency protocols as well. Results show that age was associated with a decrease in total scores on structured single-word production tests as well as a decrease in the lexical frequency of nouns selected for production. Age was also associated with the production of words that appeared in 1 picture description only or in 1 fluency protocol only. Instead of selecting the most common nouns and thus avoiding age-associated retrieval difficulties, older speakers appear to produce more infrequent nouns, most likely because they have a larger vocabulary from which to choose these nouns.