How older adults use cognition in sentence-final word recognition.

This study examined the effects of executive control and working memory on older adults' sentence-final word recognition. The question we addressed was the importance of executive functions to this process and how it is modulated by the predictability of the speech material. To this end, we tested 173 neurologically intact adult native English speakers aged 55-84 years. Participants were given a sentence-final word recognition test in which sentential context was manipulated and sentences were presented in different levels of babble, and multiple tests of executive functioning assessing inhibition, shifting, and efficient access to long-term memory, as well as working memory. Using a generalized linear mixed model, we found that better inhibition was associated with higher accuracy in word recognition, while increased age and greater hearing loss were associated with poorer performance. Findings are discussed in the framework of semantic control and are interpreted as supporting a theoretical view of executive control which emphasizes functional diversity among executive components.

Effects of metabolic syndrome on language functions in aging.

This study explored effects of the metabolic syndrome (MetS) on language in aging. MetS is a constellation of five vascular and metabolic risk factors associated with the development of chronic diseases and increased risk of mortality, as well as brain and cognitive impairments. We tested 281 English-speaking older adults aged 55-84, free of stroke and dementia. Presence of MetS was based on the harmonized criteria (Alberti et al., 2009). Language performance was assessed by measures of accuracy and reaction time on two tasks of lexical retrieval and two tasks of sentence processing. Regression analyses, adjusted for age, education, gender, diabetes, hypertension, and heart disease, demonstrated that participants with MetS had significantly lower accuracy on measures of lexical retrieval (action naming) and sentence processing (embedded sentences, both subject and object relative clauses). Reaction time was slightly faster on the test of embedded sentences among those with MetS. MetS adversely affects the language performance of older adults, impairing accuracy of both lexical retrieval and sentence processing. This finding reinforces and extends results of earlier research documenting the negative influence of potentially treatable medical conditions (diabetes, hypertension) on language performance in aging. The unanticipated finding that persons with MetS were faster in processing embedded sentences may represent an impairment of timing functions among older individuals with MetS.

Biomarkers of "Linguistic Anxiety" in aphasia: a proof-of-concept case study.

This is a proof-of-concept case study designed to evaluate the presence of "Linguistic Anxiety" in a person with mild aphasia. The participant (aged 68) was tested on linguistic and non-linguistic cognitive tasks administered under conditions that differed in levels of anxiety. A validated anxiety-induction technique rarely used in previous aphasia studies was employed: the participant was instructed to prepare for a public speaking presentation. Measures of linguistic and non-linguistic cognitive performance, and anxiety (self-report and psychophysiologic) were obtained. The participant exhibited increased psychophysiologic stress reactivity (heart rate, skin conductance and self-report ratings) in the high-anxiety condition. In the state of increased anxiety, performance on language tasks, in particular discourse production, declined relative to performance in low-anxiety settings. Even in mild aphasia, language-based anxiety can interfere with language performance. This finding provides a basis for carrying out a study with a larger sample that can open a new path to assessment and treatment of persons with aphasia.