The profile of executive functioning in amnestic mild cognitive impairment: disproportionate deficits in inhibitory control.

Amnestic mild cognitive impairment (aMCI) represents a group of individuals who are highly likely to develop Alzheimer's disease (AD). Although aMCI is typically conceptualized as involving predominantly deficits in episodic memory, recent studies have demonstrated that deficits in executive functioning may also be present, and thorough categorization of cognitive functioning in MCI may improve early diagnosis and treatment of AD. We first provide an extensive review of neuropsychology studies that examined executive functioning in MCI. We then present data on executive functioning across multiple sub-domains (divided attention, working memory, inhibitory control, verbal fluency, and planning) in 40 aMCI patients (single or multiple domain) and 32 normal elderly controls (NECs). MCI patients performed significantly worse than NECs in all 5 sub-domains, and there was impairment (>1.0 SD below the mean of NECs) in all sub-domains. Impairment on each test was frequent, with 100% of MCI patients exhibiting a deficit in at least one sub-domain of executive functioning. Inhibitory control was the most frequently and severely impaired. These results indicate that executive dysfunction in multiple sub-domains is common in aMCI and highlights the importance of a comprehensive neuropsychological evaluation for fully characterizing the nature and extent of cognitive deficits in MCI.

Communicative clusters after a right-hemisphere stroke: are there universal clinical profiles?.

OBJECTIVE: The current research aimed at classifying communication profiles among right-brain-damaged adults with an intercultural perspective, and so begins to fill in a long-standing gap in the literature. METHOD: The sample was made up of 112 right-brain-damaged individuals from three nationalities (Canadians, Brazilians and Argentineans). They were assessed using 13 language tasks from the Protocol MEC in Spanish, Brazilian Portuguese and French. RESULTS: A hierarchical cluster analysis led to four distinct clinical profiles of communication. Since only a few distinctions between nationalities were observed, the results suggest that there probably is a partial universality of clinical profiles of communication impairments after a right brain damage. CONCLUSIONS: This study proposes a preliminary taxonomy of communication disorders among right-brain-damaged individuals with cross-cultural implications. The exploration of associated stroke sites and neuropsychological concomitant deficits would contribute to the eventual development of a more accurate clinical intervention.

Differences in participation according to specific cognitive deficits following a stroke.

This study compared participation following a stroke according to the presence of specific cognitive deficits. Participation is defined as the involvement of a person in daily activities and social roles. Three weeks after being discharged home, 197 older adults (aged 65 years and older) who had a stroke were evaluated using the Assessment of Life Habits, which includes 12 domains of daily activities and social roles. The presence of a cognitive deficit was determined by the scores obtained on tests assessing memory, visual perception, language, unilateral attention, and the inhibition component of executive functions. After adjusting for depressive symptoms, time since stroke, and comorbidities, five of the domains of participation are significantly more restricted by some cognitive deficits. Memory deficits affect the communication (p = .006) and leisure (p = .032) domains. In the presence of visual perception deficits, the nutrition (p = .019), communication (p = .004), and responsibilities (p < .0005) domains are more limited. Language deficits have an impact on several domains of participation, namely communication (p < .0005), responsibilities (p < .0005), community life (p = .001), and leisure (p = .021). Unilateral neglect and deficits in the inhibition component of executive functions are not found to restrict participation. Overall, participation after stroke is related to cognitive function. Looking carefully at individual domains of activities and roles provides essential information in guiding rehabilitation interventions aimed at enhancing participation after discharge.

Partial measurement equivalence of French and English versions of the Canadian Study of Health and Aging neuropsychological battery.

Neuropsychological batteries are often translated for use across populations differing in preferred language. Yet, equivalence in construct measurement across groups cannot be assumed. To address this issue, we examined data from the Canadian Study of Health and Aging, a large study of older adults. We tested the hypothesis that the latent variables underlying the neuropsychological battery administered in French or English were the same (invariant). The best-fitting baseline model, established in the English-speaking Exploratory sample (n = 716), replicated well in the English-speaking Validation sample (n = 715), and the French-speaking sample (FS, n = 446). Across the English- and FSs, two of the factors, Long-term Retrieval and Visuospatial speed, displayed invariance, that is, reflected the same constructs measured in the same scales. In contrast, the Verbal Ability factor showed only partial invariance, reflecting differences in the relative difficulty of some tests of language functions. This empirical demonstration of partial measurement invariance lends support to the continued use of these translated measures in clinical and research contexts and illustrates a framework for detailed evaluation of the generality of models of cognition and psychopathology, across groups of any sort.

Short-term changes in and predictors of participation of older adults after stroke following acute care or rehabilitation.

BACKGROUND: Stroke can lead to restrictions in participation in daily activities and social roles. Although considered an important rehabilitation outcome, little is known about participation after stroke and its predictors, and about the differences associated with the types of services provided following stroke. OBJECTIVE: The aims of this study were 1) to follow and compare changes in participation of older adults discharged home after stroke from acute care or postacute rehabilitation, and 2) to identify the best predictors of participation after stroke from physical, cognitive, perceptual, and psychological ability measures taken shortly after discharge. METHODS: Level of participation in daily activities and social roles of 197 older adults who had a stroke was evaluated at 2 to 3 weeks (T1), 3 months (T2), and 6 months (T3) after being discharged home from acute care (n = 86) or rehabilitation (n = 111). Physical, cognitive, perceptual, and psychological abilities were assessed at T1. RESULTS: A significant increase in participation was found over time for both groups, mainly in the first 3 months. The best predictors of participation differed between the groups and between the daily activities and social roles domains. Walking and acceptance of the stroke or fewer depressive symptoms were the best predictors of the level of participation after stroke. CONCLUSIONS: Participation was not optimal at discharge because it continued to increase after the return home. The importance of psychological factors in participation after stroke is undeniable. Many predictors are amenable to interventions.

Brazilian version of the Protocole Montréal d'Evaluation de la Communication (Protocole MEC): normative and reliability data.

The lack of standardized instruments to evaluate communication disorders related to the right hemisphere was verified. A new evaluation tool was developed: Protocole Montréal d'Evaluation de la Communication--Protocole MEC, adapted to Brazilian Portuguese--Bateria Montreal de Avaliação da Comunicação--Bateria MAC (Montreal Evaluation of Communication Battery). The purpose was to present stratified normative data by age and educational level, and to verify the reliability parameters of the MEC Battery. 300 individuals, between the ages of 19 and 75 years, and levels of formal education between 2 and 35 years, participated in this study. They were divided equally into six normative groups, according to three age categories (young adults, intermediary age, and seniors) and two educational levels (low and high). Two procedures were used to check reliability: Cronbach alpha and reliability between evaluators, Results were established at the 10th percentile, and an alert point per task for each normative group. Cronbach's alpha was, in general, between .70 and .90 and the average rate of agreement between evaluators varied from .62 to .94. Standards of age and education were established. The reliability of this instrument was verified. The psychometric legitimization of the MEC Battery will contribute to the diagnostic process for communicative disorders.

Narrative Discourse in Young and Older Adults: Behavioral and NIRS Analyses.

Discourse comprehension is at the core of communication capabilities, making it an important component of elderly populations' quality of life. The aim of this study is to evaluate changes in discourse comprehension and the underlying brain activity. Thirty-six participants read short stories and answered related probes in three conditions: micropropositions, macropropositions and situation models. Using near-infrared spectroscopy (NIRS), the variation in oxyhemoglobin (HbO2) and deoxyhemoglobin (HbR) concentrations was assessed throughout the task. The results revealed that the older adults performed with equivalent accuracy to the young ones at the macroproposition level of discourse comprehension, but were less accurate at the microproposition and situation model levels. Similar to what is described in the compensation-related utilization of neural circuits hypothesis (CRUNCH) model, older participants tended to have greater activation in the left dorsolateral prefrontal cortex while reading in all conditions. Although it did not enable them to perform similarly to younger participants in all conditions, this over-activation could be interpreted as a compensation mechanism.

Lateralized Affective Word Priming and Gender Effect.

Affective priming research suggests that processing of affective words is a quick and short lived process. Using the divided visual field (DVF) paradigm, investigations of the lateralization of affective word processing have yielded inconsistent results. However, research on semantic processing of words generally suggests that the left hemisphere (LH) is the location where rapid processing occurs. We investigated the processing of affective (emotional) words using a combination of the DVF and affective priming paradigms, and four stimulus onset asynchronies (SOAs)-0, 150, 300, and 750 ms. The priming pattern yielded by males (n = 32) showed quick priming (at 0-ms SOA) of affective words in the LH; there was slower right hemisphere (RH) priming of affective words (at 750-ms SOA). In females (n = 28), both hemispheres were associated with quick priming of affective words (at 300-ms SOA in the LH and at 150-ms SOA in the RH). Results demonstrate the capability of both cerebral hemispheres in the processing of words with affective meaning, along with leading role of the left hemisphere in this process. This is similar to the results of semantic research that suggest access to word meanings occurs in both hemispheres, but different mechanisms might be involved. While the LH seems to prime affective words quickly regardless of gender, gender differences are likely in the RH in that affective word processing probably occurs slowly in males but rapidly in females. This gender difference may result from increased sensitivity to the emotional feature of affective words in females.

Applicability of a toolkit for geriatric rehabilitation outcomes.

PURPOSE: To field test the applicability of a multidimensional toolkit for geriatric rehabilitation outcomes which includes nine standardized tools. Applicability is defined as context- and population-specific pragmatic qualities of an assessment tool such as respondent and examiner burden, score distribution and format compatibility. METHOD: A sample of 48 older adults representing four diagnostic groups, as well as 26 caregivers, were assessed at home in the first month after discharge from intensive rehabilitation (T1) and 2 months later (T2). Pre-determined qualitative and quantitative applicability criteria were coded and compared at T1 and T2, as well as responsiveness. RESULTS: A higher respondent burden was found for three self-report tools, as well as a ceiling effect on social functioning tools. Respondent burden, examiner burden and score distribution remained stable or diminished at T2. Format compatibility deteriorated only for the mobility test due to a higher proportion of non ambulatory participants (17%). Low to moderate associations between the tools corroborated that they were not redundant (rPearson

[Text comprehension, cognitive resources and aging]. / Compréhension de textes, ressources cognitives et vieillissement.

Aging brings cognitive changes. Language is not immune to these changes. The use of compensation strategies may permit older adults to achieve a performance level identical to the one obtained by younger adults. This research aims to study text comprehension in aging and the reading strategies used for by older and younger adults. Kintsch's cognitive model (1988) allows the identification of different levels of representation within text treatment (linguistic form, macrostructure, microstructure and situation model) and predicts the underlying cognitive components. Eye-tracking analyses during reading permit inference about the moments of reading treatment and detection of reading strategies. Sixty highly educated participants were assessed. They were divided in two age groups (20-40 and 60-80 years old). Participants were asked to read and understand three texts constructed to highlight the features of text comprehension within each one of the different levels of text representation. The amount of detail and the necessity of updating the situation model varied for each text. Eye movements were registered by an eye-tracker (Cambridge research) during the reading process. Specific complementary tasks were administered to evaluate working memory, long-term memory, and executive functions. Variances analyses showed significantly lower performance by older adults regarding: 1) recall of the microstructure of the two texts with a high degree of detail, 2) macrostructure of the text with fewer details, and 3) performance on all tasks that evaluated cognitive components. Aging influenced treatment of levels of text representation depending on text characteristics. However, cluster analysis of the text comprehension and eye-tracker data revealed a group of older adults whose performance in reading comprehension was identical to the performance of younger adults, with the same reading profile. This result seems to show that use of compensation strategies by older adults at the onset of signs of cognitive deterioration is not necessary in reading.

[Normal aging and cognition]. / Vieillissement normal et cognition.

It is now well documented that normal aging modifies the cognitive functioning and most observations suggest that cognition evolves in the direction of deterioration. The more frequently impaired functions are memory, attention and visual-spatial abilities. On the other hand, some abilities seem to increase, such as vocabulary. Considering the aging effect on cognition, questions remain regarding directionality, universality and reversibility. A great variability in aged related impacts is observed among subjects and among cognitive domains. Some individuals evolved more rapidly than others. Some cognitive functions are more affected by aging than others. General and specific factors are hypothesized to explain the aged related cognitive decline. Among them, educational level, health, cognitive style, life style, personality, are likely to modulate the aged related cognitive evolution by influencing attentional resources and cerebral plasticity. Cognitive resources are essential to develop adaptative strategies. During the life span, resources are activated and increased by learning and training. Considering the role of cognitive resources, successful aging is dependent on several conditions : absence of disease leading to a loss of autonomy, maintenance of cognitive and physical activities, and active and social engaged lifestyle.

The heterogeneity of picture-supported narratives in Alzheimer's disease.

This study describes discourse patterns produced by 46 Alzheimer disease (AD) patients and 53 normal elderly subjects in two picture-supported narratives. Nine measures derived from a cognitive model of discourse processing were obtained and submitted to cluster analysis. Results indicate that discourse patterns elicited from both stimuli were heterogeneous. Further, they fail to clearly differentiate between normal aging and AD in half of the AD patients. Discourse patterns are examined in light of various sources of heterogeneity including severity of cognitive impairment, subject characteristics, and task demands. The usefulness of discourse as a diagnostic and therapeutic tool is discussed.

[Communication, discourse and dementia]. / Communication, discours et démence.

The construction-integration model (Kintsch, 1988) offers a frame for discourse analysis. This model defines four representation levels: the surface level or linguistic form, the base text or semantic level, the situation model built by combining information from the text and personal world knowledge, and the organization level. This study describes discourse produced by 46 Alzheimer patients and 53 normal elderly subjects in two picture-elicited production tasks: a single picture and a sequence of pictures. Globally, the single picture task is a more difficult situation for Alzheimer patients. The impaired levels in dementia are surface level, situation model and organization. Therefore, Kintsch model allows a distinction among discourse productions by normal elderly and mild to moderate Alzheimer patients.

Development of a conceptual framework for the assessment of geriatric rehabilitation outcomes.

The objective of the study was to develop a conceptual framework of key assessment areas for the evaluation of rehabilitation outcomes in older persons. The study was designed in four stages. First, a review of the literature generated a list of 84 potential outcome variables. Second, semi-structured interviews were conducted with older adults informants (n = 19) to record their thoughts about important rehabilitation outcomes. From the analyses of the transcripts, 20 recurrent themes became apparent. Third, relevant assessment areas were determined based on the merged data from the literature and the interviews. Fourth, a focus group was held with a panel of eight interdisciplinary experts with strong involvement in geriatric rehabilitation to evaluate, improve, and validate the preliminary work. As a result of the study, the conceptual framework for the assessment of geriatric rehabilitation outcomes (FAGRO) is composed of four primary outcome domains related to important activities for community-living older persons: mobility activities, basic activities of daily living, activities of independent living, and leisure activities. The models also allows for four brief evaluations of underlying functioning components, including: physical functioning, psychological functioning, social functioning, and factors related to the caregiver status and available resources. The model has the potential to become a valuable additional tool for outcome assessment, researched and developed specifically for geriatric rehabilitation.

Verbal fluency in right brain damage: dissociations among production criteria and duration.

This study aimed to verify dissociations in the performance of verbal fluency tasks with different production criteria and duration following vascular right-hemisphere damage. We tested the hypothesis that longer fluency tasks would be more sensitive in identifying deficits in the sample. The relationship between verbal fluency performance and sustained attention was also investigated. Forty adults with vascular right-hemisphere damage were assessed using verbal fluency tasks with three different production criteria (unconstrained, phonemic, and semantic fluencies from the Montreal Communication Evaluation Battery). Performance deficits in 1-min and 2-min fluency tasks were calculated (Z score) and compared (chi-square). Results did not suggest a difference in sensitivity between the task lengths in detecting cognitive impairment. However, double dissociations were found, highlighting the contribution of extended verbal fluency tasks to neuropsychological assessment. Analyses also showed that participants exhibited greater levels of impairment in the semantic fluency task. No relationship was identified between performance in sustained attention tasks and verbal fluency tasks, regardless of the latter's duration. The combined use of longer and shorter fluency tasks in the assessment of patients with right brain damage may contribute to the identification of different executive function impairments in this sample.

Working memory training and poetry-based stimulation programs: are there differences in cognitive outcome in healthy older adults?

BACKGROUND: Neuropsychological interventions have been mainly applied with clinical populations, in spite of the need of preventing negative changes across life span. Among the few studies of cognitive stimulation in elderly, surprisingly there is no enough research comparing direct and indirect active stimulation programs. OBJECTIVE: This study aims to verify wheter there are differences between two cognitive interventions approaches in older adults: a structured Working Memory (WM) Training Program versus a Poetry-based Stimulation Program. METHODS: Fourteen older adults were randomly assigned to participate into one of the two intervention groups. The assessed neurocognitive components were attention, episodic and working memory, communicative and executive functions. WM Training activities were based on Baddeley's model; Poetry-based Stimulation Program was composed by general language activities. Data were analyzed with one-way ANCOVA with Delta scores and pre and post-training tests raw scores. RESULTS: WM group improved performance on WM, inhibition, and cognitive flexibility measures, while Poetry group improved on verbal fluency and narrative discourse tasks. DISCUSSION: Both approaches presented benefits; however WM Training improved its target function with transfer effects to executive functions, being useful for future studies with a variety of dementias. Poetry-based Stimulation also improved complex linguistic abilities. Both approaches may be helpful as strategies to prevent dysfunctional aging changes.

Contribution of NIRS to the study of prefrontal cortex for verbal fluency in aging.

Healthy aging is characterized by a number of changes on brain structure and function. Several neuroimaging studies have shown an age-related reduction in hemispheric asymmetry on various cognitive tasks, a phenomenon captured by Cabeza (2002) in the Hemispheric Asymmetry Reduction in Older Adults (HAROLD) model. Although this phenomenon is supported by a range of neuroimaging data on memory and inhibitory processes, there is little evidence concerning changes in hemispheric asymmetry for language processing, and particularly word retrieval, which is assessed with verbal fluency task (VFT). This study aimed to investigate the age-related changes in cerebral oxygenation in the prefrontal cortex for both letter and category VFT, varying the complexity of the criteria (i.e., degree of productivity) and using near-infrared spectroscopy (NIRS). Sixteen younger and 16 older adults participated in this study. For both VF conditions, participants were instructed to pronounce as many nouns as possible as a function of high-productivity (e.g., "animals" or "L") or low-productivity (e.g., "flowers" or "V") criteria. Behavioral data (i.e., accuracy responses) showed comparable performance in younger and older adults for both VF conditions. However, NIRS data showed more reduced activation (i.e., significantly reduced increase in [O(2)Hb] and reduced decrease in [HHb]) in older than younger adults for both VFT. In addition, a bilateral effect was found for both groups, suggesting that VFT requires both executive and language functions. The results are discussed in the context of the current theories of aging.

Neurofunctional (re)organization underlying narrative discourse processing in aging: evidence from fNIRS.

Relatively few studies have analyzed the mechanisms underlying the cognitive changes that affect language in the elderly, and fewer have done so for narrative discourse. The goal of this study was to explore the neurofunctional changes associated with aging for different components of narrative discourse. Functional near-infrared spectroscopy (fNIRS) and behavioral data on 10 younger adults and 10 healthy elderly participants were collected. Ten younger adults in a non-proficient second language condition were included to explore the possibility that the age-related neurofunctional reorganization partly expresses demanding resource allocation. Results show within- and across-hemispheric differences in the neurofunctional pattern of activation in the older participants with reference to the younger ones, partially shared with the low-proficiency young adults, providing support for the recognized mechanisms underlying neural reserve and compensation. fNIRS was shown to be appropriate for studying the age-related neurofunctional reorganization of complex cognitive abilities.

Clinical Focus on Prosodic, Discursive and Pragmatic Treatment for Right Hemisphere Damaged Adults: What's Right?

Researchers and clinicians acknowledge today that the contribution of both cerebral hemispheres is necessary to a full and adequate verbal communication. Indeed, it is estimated that at least 50% of right brain damaged individuals display impairments of prosodic, discourse, pragmatics and/or lexical semantics dimensions of communication. Since the 1990's, researchers have focused on the description and the assessment of these impairments and it is only recently that authors have shown interest in planning specific intervention approaches. However, therapists in rehabilitation settings still have very few available tools. This review of recent literature demonstrates that, even though theoretical knowledge needs further methodological investigation, intervention guidelines can be identified to target right hemisphere damage communication impairments in clinical practice. These principles can be incorporated by speech and language pathologists, in a structured intervention framework, aiming at fully addressing prosodic, discursive and pragmatic components of communication.

Participation after a stroke: changes over time as a function of cognitive deficits.

Participation refers to the engagement of a person in daily activities and social roles. The goal of this study was to compare changes in older adults' participation over time following a stroke as a function of the presence of deficits in memory, visual perception, executive functions, visual attention or language. A total of 197 persons with stroke were assessed 3 weeks, 3 months and 6 months after discharge from an acute care hospital, rehabilitation unit or geriatric day hospital. The Assessment of Life Habits (ALH) was used to measure participation. Neuropsychological measures were used to assess the presence of a cognitive deficit in the domains of memory, visual perception, executive functions (inhibition), visual attention and language. Overall, results indicate that participation after a stroke improves over time after hospital discharge in spite of cognitive deficits. Changes in participation over time differed between unimpaired and impaired participants only for language and executive deficits in three domains: interpersonal relationships, community life and responsibilities. These results indicate that when returning to the community after a stroke, positive changes in participation over time are possible even with cognitive deficits.