Demographic Effects on Longitudinal Semantic Processing, Working Memory, and Cognitive Speed.

OBJECTIVES: To better understand and compare effects of aging and education across domains of language and cognition, we investigated whether (a) these domains show different associations with age and education, (b) these domains show similar patterns of age-related change over time, and (c) education moderates the rate of decline in these domains. METHOD: We analyzed data from 306 older adults aged 55-85 at baseline of whom 116 returned for follow-up 4-8 years later. An exploratory factor analysis identified domains of language and cognition across a range of tasks. A confirmatory factor analysis analyzed cross-sectional associations of age and education with these domains. Subsequently, mixed linear models analyzed longitudinal change as a function of age and moderation by education. RESULTS: We identified 2 language domains, that is, semantic control and semantic memory efficiency, and 2 cognitive domains, that is, working memory and cognitive speed. Older age negatively affected all domains except semantic memory efficiency, and higher education positively affected all domains except cognitive speed at baseline. In language domains, a steeper age-related decline was observed after age 73-74 compared to younger ages, while cognition declined linearly with age. Greater educational attainment did not protect the rate of decline over time in any domain. DISCUSSION: Separate domains show varying effects of age and education at baseline, language versus cognitive domains show dissimilar patterns of age-related change over time, and education does not moderate the rate of decline in these domains. These findings broaden our understanding of age effects on cognitive and language abilities by placing observed age differences in context.

The Role of Executive Functions in Object- and Action-Naming among Older Adults.

Background/Study Context: Lexical retrieval abilities and executive function skills decline with age. The extent to which these processes might be interdependent remains unknown. The aim of the current study was to examine whether individual differences in three executive functions (shifting, fluency, and inhibition) predicted naming performance in older adults. Methods: The sample included 264 adults aged 55-84. Six measures of executive functions were combined to make three executive function composites scores. Lexical retrieval performance was measured by accuracy and response time on two tasks: object naming and action naming. We conducted a series of multiple regressions to test whether executive function performance predicts naming abilities in older adults. Results: We found that different executive functions predicted naming speed and accuracy. Shifting predicted naming accuracy for both object and action naming while fluency predicted response times on both tests as well as object naming accuracy, after controlling for education, gender, age, working memory span, and speed of processing in all regressions. Interestingly, inhibition did not contribute to naming accuracy or response times on either task. Conclusion: The findings support the notion that preservation of some executive functions contributes to successful naming in older adults and that different executive functions are associated with naming speed and accuracy.

Breathe Easy, Speak Easy: Pulmonary Function and Language Performance in Aging.

BACKGROUND: This study explored the association between pulmonary function (PF) and older adults' language performance accuracy. Study rationale was anchored in aging research reporting PF as a reliable risk factor affecting cognition among the elderly. METHODS: 180 adult English native speakers aged 55 to 84 years participated in the study. PF was measured through forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio (FFR). Language performance was assessed with an action naming test and an object naming test, and two tests of sentence comprehension, one manipulating syntactic complexity and the other, semantic negation. Greater PF was predicted to be positively associated with all tasks. RESULTS: Unadjusted models revealed FVC and FEV1 effects on language performance among older adults. Participants with higher FVC showed better naming on both tasks and those with higher FEV1 had better object naming only. In covariate-adjusted models, only a positive FVC-object naming association remained. CONCLUSION: Findings were discussed in terms of brain oxygenation mechanisms, whereby good PF may implicate efficient oxygenation, supporting neurotransmitter metabolism that protects against neural effects of cerebrovascular risk. Effects on object naming were linked to putative differential oxygenation demands across language tasks.

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.

Neuroscience of aphasia recovery: the concept of neural multifunctionality.

Aphasia therapy, while demonstrably successful, has been limited by its primary focus on language, with relatively less attention paid to nonlinguistic factors (cognitive, affective, praxic) that play a major role in recovery from aphasia. Neuroscientific studies of the past 15-20 years have opened a breach in the wall of traditional clinico-anatomical teachings on aphasia. It is not an exaggeration to talk of a paradigm shift. The term "neural multifunctionality" denotes a complex web of neural networks supporting both linguistic and nonlinguistic functions in constant and dynamic interaction, creating language as we know it and contributing to recovery from aphasia following brain damage. This paper reviews scientific underpinnings of neural multifunctionality and suggests ways in which this new approach to understanding the neural basis of language can lead to meaningful, practical steps for improvements in aphasia therapy.

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.

Brain and language: evidence for neural multifunctionality.

This review paper presents converging evidence from studies of brain damage and longitudinal studies of language in aging which supports the following thesis: the neural basis of language can best be understood by the concept of neural multifunctionality. In this paper the term "neural multifunctionality" refers to incorporation of nonlinguistic functions into language models of the intact brain, reflecting a multifunctional perspective whereby a constant and dynamic interaction exists among neural networks subserving cognitive, affective, and praxic functions with neural networks specialized for lexical retrieval, sentence comprehension, and discourse processing, giving rise to language as we know it. By way of example, we consider effects of executive system functions on aspects of semantic processing among persons with and without aphasia, as well as the interaction of executive and language functions among older adults. We conclude by indicating how this multifunctional view of brain-language relations extends to the realm of language recovery from aphasia, where evidence of the influence of nonlinguistic factors on the reshaping of neural circuitry for aphasia rehabilitation is clearly emerging.

Psycholinguistics of Aphasia Pharmacotherapy: Asking the Right Questions.

BACKGROUND: Among the obstacles to demonstrating efficacy of pharmacological intervention for aphasia is quantifying patients' responses to treatment in a statistically valid and reliable manner. In many of the review papers on this topic (e.g., Berthier et al., 2011; de Boissezon, Peran, de Boysson, & Démonet, 2007; Small & Llano, 2009), detailed discussions of various methodological problems are highlighted, with some suggestions on how these shortcomings should be addressed. Given this deep understanding of caveats associated with the experimental design of aphasia pharmacotherapy studies (e.g., Berthier et al., 2011), investigations continue to produce inconsistent results. AIM: In this review paper we suggest that inclusion of theory-driven linguistic measures in aphasia pharmacotherapy studies would add an important step toward elucidating precise patterns of improvement in language performance resulting from pharmacotherapeutic intervention. MAIN CONTRIBUTION: We provide a brief review of the clinical approaches currently used in pharmacotherapy studies of aphasia, which often lack psycholinguistic grounding. We then present ways in which psycholinguistic models can complement this approach, offering a rationale for task selection, and as a result, lead to a better understanding of treatment effects. We then follow with an example of how such an integrative approach can be implemented in studies targeting stress reduction in people with aphasia, via beta-blocking agents, as a means to augment language performance, using the psycholinguistic framework of "linguistic anxiety" outlined in Cahana-Amitay et al, 2011 as our guideline. CONCLUSION: We conclude that the incorporation of psycholinguistic models into aphasia pharmacotherapy studies can increase the resolution with which we can identify functional changes.

Effects of hypertension and diabetes on sentence comprehension in aging.

OBJECTIVES: To assess the impact of hypertension and diabetes mellitus on sentence comprehension in older adults. METHOD: Two hundred and ninety-five adults aged 55 to 84 (52% men) participated in this study. Self-report mail survey combined with medical evaluations were used to determine eligibility. Multiple sources were used to determine whether hypertension and diabetes were present or absent and controlled or uncontrolled. Sentence comprehension was evaluated with two tasks: embedded sentences (ES) and sentences with multiple negatives (MN). Outcome measures were percent accuracy and mean reaction time of correct responses on each task. RESULTS: Regression models adjusted for age, gender, and education showed that the presence of hypertension impaired comprehension on the multiple negatives task (p < .01), whereas the presence of diabetes impaired the comprehension of embedded sentences (p < .05). Uncontrolled diabetes significantly impaired accurate comprehension of sentences with multiple negatives (p < .05). No significant patterns were found for reaction time. DISCUSSION: The presence of hypertension and diabetes adversely affected sentence comprehension, but the relative contribution of each was different. These findings support the researchers' earlier speculations on the neurobiological mechanisms underlying the effects of hypertension and diabetes on language and cognition in aging. Uncontrolled disease status demonstrated more complicated age-related effects on sentence processing, highlighting the clinical importance for cognitive aging of identifying and managing vascular risk factors.

The contribution of set switching and working memory to sentence processing in older adults.

This study evaluates the involvement of switching skills and working-memory capacity in auditory sentence processing in older adults. The authors examined 241 healthy participants, aged 55 to 88 years, who completed four neuropsychological tasks and two sentence-processing tasks. In addition to age and the expected contribution of working memory, switching ability, as measured by the number of perseverative errors on the Wisconsin Card Sorting Test, emerged as a strong predictor of performance on both sentence-processing tasks. Individuals with both low working-memory spans and more perseverative errors achieved the lowest accuracy scores. These findings are consistent with compensatory accounts of successful performance in older age.

Language as a Stressor in Aphasia.

BACKGROUND: Persons with aphasia often report feeling anxious when using language while communicating. While many patients, caregivers, clinicians and researchers would agree that language may be a stressor for persons with aphasia, systematic empirical studies of stress and/or anxiety in aphasia remain scarce. AIM: The aim of this paper is to review the existing literature discussing language as a stressor in aphasia, identify key issues, highlight important gaps, and propose a program for future study. In doing so, we hope to underscore the importance of understanding aspects of the emotional aftermath of aphasia, which plays a critical role in the process of recovery and rehabilitation. MAIN CONTRIBUTION: Post stroke emotional dysregulation in persons with chronic aphasia clearly has adverse effects for language performance and prospects of recovery. However, the specific role anxiety might play in aphasia has yet to be determined. As a starting point, we propose to view language in aphasia as a stressor, linked to an emotional state we term "linguistic anxiety." Specifically, a person with linguistic anxiety is one in whom the deliberate, effortful production of language involves anticipation of an error, with the imminence of linguistic failure serving as the threat. Since anticipation is psychologically linked to anxiety and also plays an important role in the allostatic system, we suggest that examining physiologic stress responses in persons with aphasia when they are asked to perform a linguistic task would be a productive tool for assessing the potential relation of stress to "linguistic anxiety." CONCLUSION: Exploring the putative relationship between anxiety and language in aphasia, through the study of physiologic stress responses, could establish a platform for investigating language changes in the brain in other clinical populations, such as in individuals with Alzheimer's disease or persons with post traumatic stress disorder, or even with healthy aging persons, in whom "linguistic anxiety" might be at work when they have trouble finding words.

Bilateral brain regions associated with naming in older adults.

To determine structural brain correlates of naming abilities in older adults, we tested 24 individuals aged 56-79 on two confrontation-naming tests (the Boston Naming Test (BNT) and the Action Naming Test (ANT)), then collected from these individuals structural Magnetic-Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI) data. Overall, several regions showed that greater gray and white matter volume/integrity measures were associated with better task performance. Left peri-Sylvian language regions and their right-hemisphere counterparts, plus left mid-frontal gyrus correlated with accuracy and/or negatively with response time (RT) on the naming tests. Fractional anisotropy maps derived from DTI showed robust positive correlations with ANT accuracy bilaterally in the temporal lobe and in right middle frontal lobe, as well as negative correlations with BNT RT, bilaterally, in the white matter within middle and inferior temporal lobes. We conclude that those older adults with relatively better naming skills can rely on right-hemisphere peri-Sylvian and mid-frontal regions and pathways, in conjunction with left-hemisphere peri-Sylvian and mid-frontal regions, to achieve their success.

Semantic verbal fluency in two contrasting languages.

This cross-linguistic study investigated Semantic Verbal Fluency (SVF) performance in 30 American English-speaking and 30 Finnish-speaking healthy elderly adults with different cultural and linguistic backgrounds. Despite the different backgrounds of the participant groups, remarkable similarities were found between the groups in the overall SVF performance in two semantic categories (animals and clothes), in the proportions of words produced within the first half (30 seconds) of the SVF tasks, and in the variety of words produced for the categories. These similarities emerged despite the difference in the mean length of words produced in the two languages (with Finnish words being significantly longer than English words). The few differences found between the groups concerned the types and frequencies of the 10 most common words generated for the categories. It was concluded that culture and language differences do not contribute significantly to variability in SVF performance in healthy elderly people.

Effects of health status on word finding in aging.

OBJECTIVES: To evaluate effects of health status on word-finding difficulty in aging, adjusting for the known contributors of education, sex, and ethnicity. DESIGN: Cross-sectional. SETTING: Community. PARTICIPANTS: Two hundred eighty-four adults aged 55 to 85 (48.6% female) participating in an ongoing longitudinal study of language in aging. MEASUREMENTS: Medical, neurological, and laboratory evaluations to determine health status and presence or absence of hypertension and diabetes mellitus. Lexical retrieval evaluated with the Boston Naming Test (BNT) and Action Naming Test. RESULTS: Unadjusted regression models showed that presence of diabetes mellitus was not related to naming. Presence of hypertension was associated with significantly lower accuracy on both tasks (P<.02). Adjustment for demographics attenuated the effect of hypertension (P<.08). For the BNT, a variable combining presence, treatment, and control of hypertension was marginally significant (P<.10), with subjects with uncontrolled hypertension being least accurate (91.4%). Previously observed findings regarding the effects of age, education, sex, and ethnicity were confirmed. CONCLUSION: In this sample of older adults, hypertension contributed to the word-finding difficulty of normal aging, but diabetes mellitus did not.

Pseudohysterical hemiparesis.

Four patients with the diagnosis of hysterical hemiparesis and normal magnetic resonance imagings were referred to us for further evaluation. All were being treated with antidepressant or antianxiety drugs or both, with no benefit. In all 4 cases single photon emission computed tomography revealed decreased regional cerebral blood flow in frontal regions in cortical areas corresponding to their neurologic deficits. In all 4 cases improvement followed neurologic treatment. We suspect that reduced blood flow in frontal regions may have produced the neurologic deficits. We call these conditions "pseudohysterical hemiparesis."

Cognitive neuroscience of delusions in aging.

Assessments and clinical understanding of late-onset delusions in the elderly are inconsistent and often incomplete. In this review, we consider the prevalence, neurobehavioral features, and neuroanatomic correlations of delusions in elderly persons - those with documented cognitive decline and those with no evidence of cognitive decline. Both groups exhibit a common phenotype: delusions are either of persecution or of misidentification. Late-onset delusions show a nearly complete absence of the grandiose, mystical, or erotomanic content typical of early onset psychoses. Absent also from both elderly populations are formal thought disorders, thought insertions, and delusions of external control. Neuroimaging and behavioral studies suggest a frontotemporal localization of delusions in the elderly, with right hemispheric lateralization in delusional misidentification and left lateralization in delusions of persecution. We propose that delusions in the elderly reflect a common neuroanatomic and functional phenotype, and we discuss applications of our proposal to diagnosis and treatment.

Modes of remembering in patients with chronic pain: relation to current pain.

The objective of our study was to assess the relation of current pain ratings to observer versus field modes of memory retrieval in patients with chronic pain. Memories from an observer perspective involve seeing oneself in the original event as if from an external point of view; memories from a field perspective involve recalling the event as if viewing it through one's own eyes. Sixty-one patients with chronic pain were asked to (1) recall a painful memory, (2) indicate whether they saw themselves in the memory (observer mode) or re-experienced events of the memory from the first-person perspective (field mode), and (3) rate various phenomenologic properties of the memory. Twenty of these pain patients were also given two frontal lobe tests to examine potential neuropsychologic correlates of memory retrieval preferences. Memory retrieval in the field mode was associated with (a) significantly higher self-reported pain scores on the McGill Pain Questionnaire, (b) nonright-handedness, and (c) poorer performance on the tests of frontal function. Patients with chronic pain who adopt the field mode of memory retrieval when recalling painful memories experience greater current pain severity than chronic pain patients who adopt observer retrieval strategies. Those adopting field retrieval strategies may also evidence frontal system neuropsychologic anomalies.