Competing complexity metrics and adults' production of complex sentences

The adequacy of 11 metrics for measuring linguistic complexity was evaluated by applying each metric to language samples obtained from 30 different adult speakers, aged 60-90 years. The analysis then determined how well each metric indexed age-group differences in complexity. In addition, individual differences in the complexity of adults' language were examined as a function of these complexity metrics using structural equation modeling techniques. In a follow-up study, judges listened to sentences in noise, rated their comprehensibility, and attempted to recall each sentence verbatim. Hierarchical multiple regression was used to evaluate the structural equation model, derived from the language samples, with respect to sentence comprehensibility and recall. While most of the metrics provided an adequate account of age-group and individual differences in complexity, the amount of embedding and the type of embedding proved to predict how easily sentences are understood and how accurately they are recalled

The structure of verbal abilities in young and older adults

This article may not exactly replicate the final version published in the APA journal. It is not the copy of record.Four language sample measures as well as measures of vocabulary, verbal fluency, and memory span were obtained from a sample of young adults and a sample of older adults. Factor analysis was used to analyze the structure of the vocabulary, fluency, and span measures for each age group. Then an "extension" analysis was performed by using structural modeling techniques to determine how the language sample measures were related to the other measures. The measure of grammatical complexity was associated with measures of working memory including reading span and digit span. Two measures, sentence length in words and a measure of lexical diversity, were associated with the vocabulary measures. The fourth measure, propositional density, was associated with the fluency measures as a measure of processing efficiency. The structure of verbal abilities in young and older adults is somewhat different, suggesting age differences in processing efficiency. (PsycINFO Database Record (c) 2010 APA, all rights reserved

Eye movements of young and older adults during reading

This article may not exactly replicate the final version published in the APA journal. It is not the copy of record.The eye movements of young and older adults were tracked as they read sentences varying in syntactic complexity. In Experiment 1, cleft object and object relative clause sentences were more difficult to process than cleft subject and subject relative clause sentences; however, older adults made many more regressions, resulting in increased regression path fixation times and total fixation times, than young adults while processing cleft object and object relative clause sentences. In Experiment 2, older adults experienced more difficulty than young adults while reading cleft and relative clause sentences with temporary syntactic ambiguities created by deleting the that complementizers. Regression analyses indicated that readers with smaller working memories need more regressions and longer fixation times to process cleft object and object relative clause sentences. These results suggest that age-associated declines in working memory do affect syntactic processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved