Aging and the vulnerability of speech to dual task demands

Tracking a digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. Tracking performance by both groups was affected by dual task demands: time on target declined and tracking error increased as dual task demands increased from the baseline condition to a moderately demanding dual task condition to a more demanding dual task condition. When dual task demands were moderate, older adults' speech rate declined but their fluency, grammatical complexity, and content were unaffected. When the dual task was more demanding, older adults' speech, like young adults' speech, became highly fragmented, ungrammatical, and incoherent. Vocabulary, working memory, processing speed, and inhibition affected vulnerability to dual task costs: vocabulary provided some protection for sentence length and grammaticality, working memory conferred some protection for grammatical complexity, and processing speed provided some protection for speech rate, propositional density, coherence, and lexical diversity. Further, vocabulary and working memory capacity provided more protection for older adults than for young adults although the protective effect of processing speed was somewhat reduced for older adults as compared to the young adults.     

Memory for the form and force of declaratives and interrogatives

Memory for the illocutionary force and surface form of direct and indirect speech acts was studied in two recall tasks. Both examined the effects of the context of original presentation on subjects’ ability to recall declarative and interrogative sentences. Subjects more accurately recalled the verbatim form of indirect requests and offers than that of direct assertions and queries. When prompted by contexts that preserved or changed in illocutionary force of a declarative or interrogative, subjects were equally likely to recall sentences originally used as indirect requests and offers. However, they more frequently recalled sentences originally used as direct assertions or queries when prompted by force-preserving contexts than when prompted by force-changing contexts.     

Metalinguistic awareness in first graders: A qualitative perspective

The purpose of this study was to investigate first graders' metalinguistic awareness using children as the direct sources of information rather than utilizing standard inferential probes. Open-ended interviews were conducted with each child for data gathering purposes, and indefinite triangulation (Cicourel, 1974) was employed as a verification technique for providing multiple perspectives with respect to interview data. The data were analyzed for emerging patterns that might reveal ways in which children manifest an awareness of language. Results indicated that underlying social interaction processes appeared to exert at least as equal an amount of influence as cognition in the development of metalinguistics.     

The effects of aging and dual task demands on language production

A digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. After training on the pursuit rotor, participants were asked to track the moving target while providing a language sample. When simultaneously engaged, young adults experienced greater dual task costs to tracking, fluency, and grammatical complexity than older adults. Older adults were able to preserve their tracking performance by speaking more slowly. Individual differences in working memory, processing speed, and Stroop interference affected vulnerability to dual task costs. These results demonstrate the utility of using a digital pursuit rotor to study the effects of aging and dual task demands on language production and confirm prior findings that young and older adults use different strategies to accommodate to dual task demands.