What do verbal fluency tasks measure? Predictors of verbal fluency performance in older adults

Meta-analyses of clinical neuropsychological tests of executive dysfunction and impulsivity in alcohol use disorder

BACKGROUND

Promising models for cognitive rehabilitation in alcohol treatment rest on a more nuanced understanding of the associated impairments in the multifaceted domains of executive functioning (EF) and impulsivity.

OBJECTIVES

This meta-analysis examined the effects of alcohol on the individual subcomponents of EF and impulsivity in recently detoxified participants, including 1) Inhibition & Self-Regulation, 2) Flexibility & Set Shifting, 3) Planning & Problem Solving, 4) Reasoning & Abstraction, and 5) Verbal Fluency. Impulsivity was further examined through an analysis of motor, cognitive, and decisional subcategories.

METHOD

Investigators searched, coded, and calculated effect sizes of impairments demonstrated in a broad range of neuropsychological tests for EF. A total of 77 studies were selected covering 48 years of research with a sample size of 5140.

RESULTS

Findings ranged from a Hedges' g effect size of 0.803 for Inhibition to a Hedges' g of 0.359 for Verbal Fluency. Results also varied for the individual subcategories of Inhibition, including a large effect size for decisional impulsivity (g = 0.817) and cognitive impulsivity (0.860), and a moderate effect size for motor impulsivity (g = 0.529). The Hayling Test, Wisconsin Card Sorting Test, and Iowa Gambling Task were the measures most sensitive for alcohol effects.

CONCLUSION

Planning, problem solving, and inhibitory abilities are significantly affected by alcohol abuse, with decisional and cognitive forms of impulsivity most impacted. Cognitive remediation targeting these deficits might increase the related functions that mediate the ability to moderate or abstain from alcohol, and so lead to improved treatment results.

Cognitive-Motor Interference on Upper Extremity Motor Performance in a Robot-Assisted Planar Reaching Task Among Patients With Stroke

OBJECTIVE

To explore motor performance on 2 different cognitive tasks during robotic rehabilitation in which motor performance was longitudinally assessed.

DESIGN

Prospective study.

SETTING

Rehabilitation hospital.

PARTICIPANTS

Patients (N=22) with chronic stroke and upper extremity impairment.

INTERVENTION

A total of 640 repetitions of robot-assisted planar reaching, 5 times a week for 4 weeks.

MAIN OUTCOME MEASURES

Longitudinal robotic evaluations regarding motor performance included smoothness, mean velocity, path error, and reach error by the type of cognitive task. Dual-task effects (DTEs) of motor performance were computed to analyze the effect of the cognitive task on dual-task interference.

RESULTS

Cognitive task type influenced smoothness (P=.006), the DTEs of smoothness (P=.002), and the DTEs of reach error (P=.052). Robotic rehabilitation improved smoothness (P=.007) and reach error (P=.078), while stroke severity affected smoothness (P=.01), reach error (P<.001), and path error (P=.01). Robotic rehabilitation or severity did not affect the DTEs of motor performance.

CONCLUSIONS

The results provide evidence for the effect of cognitive-motor interference on upper extremity performance among participants with stroke using a robotic-guided rehabilitation system.

Examining lexical processing with two word tasks using the schizotypy analogue

Semantic processing is impaired in schizophrenia, and is often assessed using word-based semantic tasks that additionally require lexical processing for accurate performance. This study aimed to examine lexical processing in relation to psychosis proneness. 61 individuals (mean age=22.92, SD=2.67) completed a schizotypy questionnaire and two lexical processing tasks (recognition and production). Results revealed no relationship between increasing schizotypy scores and overall performance on either lexical processing task. Lexical processing performance is not related to psychosis-proneness. This is discussed in relation to schizophrenia semantic processing research.

Computerized Analysis of Verbal Fluency: Normative Data and the Effects of Repeated Testing, Simulated Malingering, and Traumatic Brain Injury

In verbal fluency (VF) tests, subjects articulate words in a specified category during a short test period (typically 60 s). Verbal fluency tests are widely used to study language development and to evaluate memory retrieval in neuropsychiatric disorders. Performance is usually measured as the total number of correct words retrieved. Here, we describe the properties of a computerized VF (C-VF) test that tallies correct words and repetitions while providing additional lexical measures of word frequency, syllable count, and typicality. In addition, the C-VF permits (1) the analysis of the rate of responding over time, and (2) the analysis of the semantic relationships between words using a new method, Explicit Semantic Analysis (ESA), as well as the established semantic clustering and switching measures developed by Troyer et al. (1997). In Experiment 1, we gathered normative data from 180 subjects ranging in age from 18 to 82 years in semantic ("animals") and phonemic (letter "F") conditions. The number of words retrieved in 90 s correlated with education and daily hours of computer-use. The rate of word production declined sharply over time during both tests. In semantic conditions, correct-word scores correlated strongly with the number of ESA and Troyer-defined semantic switches as well as with an ESA-defined semantic organization index (SOI). In phonemic conditions, ESA revealed significant semantic influences in the sequence of words retrieved. In Experiment 2, we examined the test-retest reliability of different measures across three weekly tests in 40 young subjects. Different categories were used for each semantic ("animals", "parts of the body", and "foods") and phonemic (letters "F", "A", and "S") condition. After regressing out the influences of education and computer-use, we found that correct-word z-scores in the first session did not differ from those of the subjects in Experiment 1. Word production was uniformly greater in semantic than phonemic conditions. Intraclass correlation coefficients (ICCs) of correct-word z-scores were higher for phonemic (0.91) than semantic (0.77) tests. In semantic conditions, good reliability was also seen for the SOI (ICC = 0.68) and ESA-defined switches in semantic categories (ICC = 0.62). In Experiment 3, we examined the performance of subjects from Experiment 2 when instructed to malinger: 38% showed abnormal (p< 0.05) performance in semantic conditions. Simulated malingerers with abnormal scores could be distinguished with 80% sensitivity and 89% specificity from subjects with abnormal scores in Experiment 1 using lexical, temporal, and semantic measures. In Experiment 4, we tested patients with mild and severe traumatic brain injury (mTBI and sTBI). Patients with mTBI performed within the normal range, while patients with sTBI showed significant impairments in correct-word z-scores and category shifts. The lexical, temporal, and semantic measures of the C-VF provide an automated and comprehensive description of verbal fluency performance.

Verbal Fluency Tasks: Effects of Age, Gender, and Education

OBJECTIVES

This study presents data for semantic fluency, phonemic fluency, action fluency, and alternate fluency. The aim is to provide normative data by age, gender, and education for European Portuguese in each fluency category.

METHODS

Norms for the verbal fluency task were collected from a volunteer population of 444 healthy Portuguese participants. Multiple regression analysis with age, gender, and education as independent variables was performed for the semantic fluency global score, and these variables were considered separately for each phonemic category.

RESULTS

Age, education, and gender significantly affected the semantic global score, as well as scores of names, supermarket, kitchen objects, food, and clothes. No gender effect was observed in the categories "p-words," animals, transports, verbs, and alternating fluency. This last category was only influenced by years of education.

CONCLUSIONS

Equivalent scores of verbal fluency tasks are useful in clinical practice, allowing the comparison between the normal and the abnormal performance of language disorders.

Semantic Verbal Fluency: Normative Data in Older Spanish Adults From NEDICES Population-Based Cohort

OBJECTIVE

We aimed to provide the normative data stratified by age, sex and educational attainment for two semantic categories (animal and fruits) in older Spanish adults.

METHOD

A representative sample of 2,744 non-demented older individuals with different socioeconomic background was selected from the Neurological Disorders in Central Spain (NEDICES), a population-based study. Normative data are presented in percentile ranks and divided into four age-tables with different midpoints, using the overlapping interval procedure.

RESULTS

Correlation analyses showed that age, education and sex influence significantly the scores in both semantic tasks. Normative data presented here covered two urban (Margaritas & Lista) and one rural areas (Arévalo).

CONCLUSION

These norms may provide useful data for screening cognitive impairment more accurately in Spanish older adults.

Worsening of Verbal Fluency After Deep Brain Stimulation in Parkinson's Disease: A Focused Review

Worsening of verbal fluency after treatment with deep brain stimulation in Parkinson's disease patients is one of the most often reported cognitive adverse effect. The underlying mechanisms of this decline are not well understood. The present focused review assesses the evidence for the reliability of the often-reported decline of verbal fluency, as well as the evidence for the suggested mechanisms including disease progression, reduced medication levels, electrode positions, and stimulation effect vs. surgical effects. Finally, we highlight the need for more systematic investigations of the large degree of heterogeneity in the prevalence of verbal fluency worsening after DBS, as well as provide suggestions for future research.

Association of neurobehavioral performance with R2* in the caudate nucleus of asymptomatic welders

OBJECTIVES

Welding fumes contain several metals including manganese (Mn) and iron (Fe) that may affect the nervous system. Previous studies of potential welding-related neurotoxicity have focused primarily on Mn exposure. The current study examined neurobehavioral and brain imaging changes in asymptomatic welders and their associations with both Mn and Fe exposure measurements.

METHODS

Data were obtained from subjects with (n=46) and without (controls; n=31) a history of welding exposure. Occupational questionnaires estimated recent (HrsW; welding hours and E₉₀; cumulative exposure, past 90days) and lifetime (YrsW; total welding years and ELT; cumulative exposure, lifetime) exposure. Brain MRI pallidal index (PI), R1 (1/T1), and R2* (1/T2*) were measured to estimate Mn and Fe concentrations in the basal ganglia [caudate nucleus (CN), putamen, and globus pallidus], amygdala, and hippocampus. Comprehensive neuropsychological tests were conducted to examine behavioral differences between welders and controls. Correlation analyses were conducted between neuropsychological tests and those exposure measurements that showed significant group differences.

RESULTS

Compared to controls, welders had significantly higher R2* in the CN and lower performance on the Phonemic Fluency test. Correlation analyses revealed that welders' Phonemic Fluency scores were inversely associated with R2* in the CN, but not with the PI or R1 in any brain region of interest studied.

DISCUSSION

The results showed that neurobehavioral performance for the asymptomatic welders in our study was worse than individuals who had not welded, and suggest the differences may be associated with higher Fe accumulation in the CN.

A comparison of theoretical and statistically derived indices for predicting cognitive decline

INTRODUCTION

Both theoretical and statistically derived approaches have been used in research settings for predicting cognitive decline.

METHODS

Fifty-eight cognitively normal (NC) and 71 mild cognitive impairment (MCI) subjects completed a comprehensive cognitive battery for up to 5 years of follow-up. Composite indices of cognitive function were derived using a classic theoretical approach and exploratory factor analysis (EFA). Cognitive variables comprising each factor were averaged to form the EFA composite indices. Logistic regression was used to investigate whether these cognitive composites can reliably predict cognitive outcomes.

RESULTS

Neither method predicted decline in NC. The theoretical memory, executive, attention, and language composites and the EFA-derived "attention/executive" and "verbal memory" composites were significant predictors of decline in MCI. The best models achieved an area under the curve of 0.94 in MCI.

CONCLUSIONS

The theoretical and the statistically derived cognitive composite approaches are useful in predicting decline in MCI but not in NC.

L-type Ca2+ channels in mood, cognition and addiction: integrating human and rodent studies with a focus on behavioural endophenotypes

Brain Cav 1.2 and Cav 1.3 L-type Ca2+ channels play key physiological roles in various neuronal processes that contribute to brain function. Genetic studies have recently identified CACNA1C as a candidate risk gene for bipolar disorder (BD), schizophrenia (SCZ), major depressive disorder (MDD) and autism spectrum disorder (ASD), and CACNA1D for BD and ASD, suggesting a contribution of Cav 1.2 and Cav 1.3 Ca2+ signalling to the pathophysiology of neuropsychiatric disorders. Once considered sole clinical entities, it is now clear that BD, SCZ, MDD and ASD share common phenotypic features, most likely due to overlapping neurocircuitry and common molecular mechanisms. A major future challenge lies in translating the human genetic findings to pathological mechanisms that are translatable back to the patient. One approach for tackling such a daunting scientific endeavour for complex behaviour-based neuropsychiatric disorders is to examine intermediate biological phenotypes in the context of endophenotypes within distinct behavioural domains. This will better allow us to integrate findings from genes to behaviour across species, and improve the chances of translating preclinical findings to clinical practice.

The Relationship between Sleep Complaints, Depression, and Executive Functions on Older Adults

Aim: In this manuscript, we report data on the association between executive functions screened by Frontal Assessment Battery, Five Digit Test and Digit Span with self-reported depressive symptoms and sleep complaints in non-demented older adults.

Methods: A total sample of 95 non-demented older adults performed Geriatric Depression Scale short version, Frontal Assessment Battery, Five Digit Test, Digit Span, and clinical interview. We split participants in groups stratified by age according to: young-old (60–69 years of age), old-old (70–79 years), and oldest-old (>80 years) and compared these three groups on the sociodemographic characteristics and executive functions performance. We carried out Poisson regression with robust error variance to verify sleep complaints and depression effects on executive functions performance. Gender, age, years of formal education, use of antidepressants and of benzodiazepines were considered as confounding variables, taking into account executive functions as dependent and sleep complaints and depression as independent variables.

Results: Controlling the effect of age, gender, years of formal education, use of benzodiazepines and of antidepressants there was a significant influence of depression in motor programming, inhibitory control, and working memory. Individuals without depression show motor programming scores 68.4% higher, inhibitory control scores 3 times greater and working memory scores also 3 times greater than individuals without depression. There was a significant influence of sleep complaints in phonemic fluency, motor programming, inhibitory control, and working memory. Individuals without sleep complaints show phonemic fluency scores 2 times greater than, motor programming scores 85.9% higher, inhibitory control scores 3 times greater and working memory scores also 3 times greater than individuals without sleep complaints.

Conclusions: Sleep complaints are associated with phonemic fluency, motor programming, inhibitory control, and working memory impairment. Depression symptoms presence are associated with motor programming and working memory performances. Depression and sleep complaints interaction would determine worse phonemic fluency, inhibitory control and working memory cognitive performance than these two conditions alone.

Early childhood exposure to short periods of sevoflurane is not associated with later, lasting cognitive deficits

BACKGROUND

A detrimental effect of commonly used anesthetics on the neurodevelopmental and behavioral parameters has long been shown in young animals subjected to early childhood anesthesia. Epidemiologic studies suggest the possibility of a modestly elevated risk of adverse neurodevelopmental outcomes in children exposed to anesthesia during early childhood. However, these results are still preliminary and inconclusive.

AIM

To further elucidate the probability of occurrence of such adverse outcomes, we evaluated cognitive performance of children who underwent general anesthesia early in their childhood.

METHOD

One hundred and fifteen children aged 5-16 years with established glaucoma were included in the study. Of these, 68 children had a history of at least one general anesthesia with sevoflurane before age 3. Phonemic and semantic verbal fluency, and forward and backward digit span tests were performed to evaluate cognitive function in the study subjects.

RESULTS

The two-way anova revealed that all these variables showed significant changes in various age groups, but they were comparable among subjects with no, single, or multiple childhood anesthesia.

CONCLUSION

It can be concluded that brief periods of anesthesia with single anesthetic sevoflurane may be safe for children under age 3.

Cognitive Dysfunction in Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a mental disorder featuring obsessions (intrusive thoughts) and compulsions (repetitive behaviors performed in the context of rigid rituals). There is strong evidence for a neurobiological basis of this disorder, involving limbic cortical regions and related basal ganglion areas. However, more research is needed to lift the veil on the precise nature of that involvement and the way it drives the clinical expression of OCD. Altered cognitive functions may underlie the symptoms and thus draw a link between the clinical expression of the disorder and its neurobiological etiology. Our extensive review demonstrates that OCD patients do present a broad range of neuropsychological dysfunctions across all cognitive domains (memory, attention, flexibility, inhibition, verbal fluency, planning, decision-making), but some methodological issues temper this observation. Thus, future research should have a more integrative approach to cognitive functioning, gathering contributions of both experimental psychology and more fundamental neurosciences.

Performance of Verbal Fluency as an Endophenotype in Patients with Familial versus Sporadic Schizophrenia and Their Parents

What’s the neurocognitive deficit as an endophenotype to familial schizophrenia? Here, we investigate the neurocognitive endophenotype in first-episode patients with familial schizophrenia (FS) and sporadic schizophrenia (SS), and their parents. 98 FS patients and their 105 parents; 190 SS patients and their 207 parents; 195 controls matched with patients, and 190 controls matched with the patients’ parents, were assessed with the short version of the Wechsler Adult Intelligence Scale-Revised in China (WAIS-RC), the immediate and delayed logical memory tests from the Wechsler Memory Scale-Revised in China (WMS-RC), the Verbal Fluency Test (VFT), the Trail Making Test Parts A and B-Modified (TMA, TMB-M), and the Modified Wisconsin Card Sorting Test (WCST-M). The results showed that with age, gender, and education as covariates, after controlling for false discovery rates, the FS group and their parent group performed worse than the SS group and their parent group on VFT. No significant differences were found for other neurocognitive tests between the FS and SS patient groups, and their respective parent groups. Our findings suggest the patients with familial and sporadic schizophrenia and their respective parent groups may have a different genetic predisposition in relation to a cognitive endophenotype.

Clinical application of DEX/CRH test and multi-channel NIRS in patients with depression

Background

To reduce the number of patients with depression, biomarkers for clarifying psychiatric disorders are warranted. Numerous candidates have been proposed; however, near-infrared spectroscopy (NIRS) with multi-channel probes and a dexamethasone/corticotropin-releasing hormone (DEX/CRH) test are still surviving for practical demand. Thirty-one outpatients with depressed moods were analyzed using both biological tests.

Results

The non-suppressors, as indicated by the DEX/CRH test, exhibited a high severity on the Hamilton Depression Scale and severe anxiety on the State Trait Anxiety Scale. In addition, a unique response was identified via NIRS in the same group suggested by the DEX/CRH assessment.

Conclusions

The results obtained from these biological tests did not fit well with the category defined by operative diagnostic criteria, such as the Diagnostic and Statistical Manual of Mental Disorders or The International Classification of Diseases. Thus, it is critical that the utility evaluations of candidate biomarkers not be assessed by comparisons with the categorized criteria for a specific psychiatric disorder.

Trial registration UMIN000013214, Registered 21 February 2014

Do Baseline Executive Functions Mediate Prospective Memory Performance under a Moderate Dose of Alcohol?

Prospective memory (PM) is memory for delayed intentions. While deleterious effects of acute doses of alcohol on PM have been documented previously using between-subjects comparisons, the current study adopted a single blind placebo-controlled within-subjects design to explore whether the extent to which alcohol-related impairments in PM are mediated by executive functions (EFs). To this end, 52 male social drinkers with no history of substance-related treatment were tested using two parallel versions of a clinical measure of PM (the Memory for Intentions Test; Raskin et al., 2010), and a battery of EF measures. Testing took place on two occasions, with the order of administration of the alcohol and placebo conditions being fully counterbalanced. Overall, PM was worse under alcohol and participants showed deficits on five of the six subscales making up the clinical test. Hierarchical multiple regression analyses demonstrated that EFs did not predict PM performance decrements overall but did predict performance when time cues were presented and when verbal responses were required. Phonemic fluency was the strongest of the EF predictors; a greater capacity to gain controlled access to information in long-term memory predicted a smaller difference between placebo- and alcohol-related performance on both the time cue and verbal response scales. PM is crucial to compliance with, and response to, both therapy programs and alcohol harm prevention campaigns. The results indicate that individual differences in cognitive function need to be taken into account when designing such interventions in order to increase their effectiveness.

Sensitivity and specificity of executive function tests for Alzheimer's disease

Decline in executive function (EF) occurs early in Alzheimer's disease (AD) and can interfere with daily functioning. Unfortunately, little is known about the relative ability of traditional EF tests to detect these cognitive changes. Given that timely diagnosis and intervention are essential to improving functional outcome in this population, our aim was to identify the specific EF measures that best differentiated mild dementia from normal aging. Thirty-one patients with mild AD and 31 controls were administered 7 EF tests. Findings indicated significant between-group differences on all measures except Wisconsin Card Sorting Test. The remaining 6 tests displayed fair to good accuracy discriminating between AD cases and controls. Only category fluency and Tower of London test remained in the final regression model that yielded the highest AUC of 0.90, which was not statistically different from that of either test alone. Overall, most of the tests employed were valid for assessing mild EF disturbances. Specifically, the two measures can be used in isolation for quick screening or in combination to facilitate a more in-depth evaluation of EF performance. This study contributes to clinical field by testifying to the validity of various EF tests to identify AD-related compromises in this cognitive domain.

Effects of age, education, and gender on verbal fluency in healthy adult Arabic-speakers in Egypt

The objective of this study is to establish the effects of age, gender, and education and to provide preliminary normative data for letter and category fluency tasks in the Egyptian Arabic-speaking population. We evaluated 139 cognitively healthy volunteers aged 20-93 by adapting the letter and category verbal fluency tasks for the Egyptian population. On the letter fluency task, mean number of words generated in one-minute beginning with the Arabic letter "Sheen" (pronounced "sh") was 8.14 words per minute (SD = 3.25). Letter fluency was significantly influenced by education. On category fluency tasks, mean number of animal names generated in one minute was 14.63 words (SD = 5.28). Category fluency was significantly influenced by age and education. We were able identify that age significantly affects category fluency while education significantly affected both letter and category fluency. We were also able to provide preliminary normative data for both tasks in the Egyptian population.

Normative data for phonemic and semantic verbal fluency test in the adult French-Quebec population and validation study in Alzheimer's disease and depression

OBJECTIVE

Verbal fluency tasks are principally used to assess lexical access and have shown usefulness for differential diagnosis. The purpose of Study 1 was to provide normative data in the adult French-Quebec population (Canada) for semantic verbal fluency (animals), for two sets of phonemic verbal fluency (TNP and PFL), and for letter P alone (60 seconds per category/letter). The objectives of Study 2 were to establish the diagnostic and predictive validity of the present tasks and normative data in Alzheimer's disease (AD) and major depressive episode (MDE).

METHOD

The normative sample consisted of 932 participants aged 19-91 years. Based on multiple linear regressions, equations to calculate Z-scores were provided. To assess validity, performance of 62 healthy participants was compared to 62 participants with AD and 41 with MDE aged over 50.

RESULTS

Age and education, but not gender, predicted performance on each verbal fluency task. Healthy adults aged 50 and younger had a better performance on semantic than phonemic verbal fluency. In comparison to MDE, AD participants had lower performance on animals and TNP, but not on letter P. Ninety percent of people with a Z-score ≤ -1.50 on semantic verbal fluency had AD and the global accuracy was 76.6%. Test-retest reliability over one year was high for both animals (r = .711) and TNP (r = .790) in healthy older participants, but dropped for animals in people with AD (r = .493).

CONCLUSIONS

These data will strengthen accurate detection of verbal fluency deficits in French-Quebec adults.

[The association between the GRIN2B gene and verbal fluency and impairment of abstract thinking in schizophrenia]

OBJECTIVE

To search for the association between the GRIN2B gene and signs of thought and speech disorders which may be the result of decreased accessibility to the mental lexicon.

MATERIAL AND METHODS

The association between the GRIN2B polymorphism rs7301328 with semantic verbal fluency and five symptoms of thought and speech disorders, as assessed with the PANSS, was studied in 552 patients with schizophrenia-spectrum disorders.

RESULTS AND CONCLUSION

There was the association of the GRIN2B gene with verbal fluency and the PANSS item «Difficulty in Abstract Thinking». The association was not modified by verbal fluency. The results suggest that the GRIN2B gene may modify the linguistic processes involved in the retrieval of information from the mental lexicon on the basis of semantic traits and, moreover, contribute to the variability of clinical symptoms of impairment of abstract thinking in patients with schizophrenia. The heterozygous genotype may be protective against the development of thought and speech disorders.

Physical frailty in late-life depression is associated with deficits in speed-dependent executive functions

OBJECTIVE

The aim of this study was to examine the association between physical frailty and neurocognitive performance in late-life depression (LLD).

METHODS

Cross-sectional design using baseline data from a treatment study of late-life depression was used in this study. Individuals aged 60 years and older were diagnosed with major depressive disorder at time of assessment (N = 173). All participants received clinical assessment of depression and completed neuropsychological testing during a depressive episode. Physical frailty was assessed using an adaptation of the FRAIL scale. Neuropsychological domains were derived from a factor analysis that yielded three factors: (i) speeded executive and fluency, (ii) episodic memory, and (iii) working memory. Associations were examined with bivariate tests and multivariate models.

RESULTS

Depressed individuals with a FRAIL score >1 had worse performance than nonfrail depressed across all three factors; however, speeded executive and fluency was the only factor that remained significant after controlling for depression symptom severity and demographic characteristics.

CONCLUSIONS

Although physical frailty is associated with broad neurocognitive deficits in LLD, it is most robustly associated with deficits in speeded executive functions and verbal fluency. Causal inferences are limited by the cross-sectional design, and future research would benefit from a comparison group of nondepressed older adults with similar levels of frailty. Research is needed to understand the mechanisms underlying associations among depression symptoms, physical frailty, and executive dysfunction and how they are related to the cognitive and symptomatic course of LLD.

Neuroanatomical correlates of verbal fluency in early Alzheimer's disease and normal aging

Verbal fluency (VF) impairments occur early in Alzheimer's disease (AD) and to a lesser extent also in normal aging. However, the neural underpinnings of these impairments are not fully understood. The present study evaluated whether VF impairments in early AD and normal aging rely upon common or different neuroanatomical correlates. We examined the association between VF performance and brain structure in 18 mild AD patients and 24 healthy elderly. Linear regressions were performed between accuracy and time intervals in VF scores and structural measurements of cerebral gray matter (GM) and white matter (WM) using MRI. Results showed that semantic VF correlated exclusively with GM in cerebellum, left temporal fusiform cortex, and WM in uncinate fasciculus, inferior fronto-occipital fasciculus and corpus callosum. Phonemic VF showed unique associations between intervals and WM in left-hemisphere tracts. The association between GM in hippocampus, subcortical structures and semantic accuracy differentiated patients from controls. Results showed that VF impairments are primarily associated with same structural brain changes in AD as in healthy elderly but at exaggerated levels. However, specific VF deficiencies and their underlying neural correlates exist and these clearly differentiate the initial stages of AD.

Dopamine pathway gene variants may modulate cognitive performance in the DHS - Mind Study

BACKGROUND

There is an established association between type 2 diabetes and accelerated cognitive decline. The exact mechanism linking type 2 diabetes and reduced cognitive function is less clear. The monoamine system, which is extensively involved in cognition, can be altered by type 2 diabetes status. Thus, this study hypothesized that sequence variants in genes linked to dopamine metabolism and associated pathways are associated with cognitive function as assessed by the Digit Symbol Substitution Task, the Modified Mini-Mental State Examination, the Stroop Task, the Rey Auditory-Verbal Learning Task, and the Controlled Oral Word Association Task for Phonemic and Semantic Fluency in the Diabetes Heart Study, a type 2 diabetes-enriched familial cohort (n = 893).

METHODS

To determine the effects of candidate variants on cognitive performance, genetic association analyses were performed on the well-documented variable number tandem repeat located in the 3' untranslated region of the dopamine transporter, as well as on single-nucleotide polymorphisms covering genes in the dopaminergic pathway, the insulin signaling pathway, and the convergence of both. Next, polymorphisms in loci of interest with strong evidence for involvement in dopamine processing were extracted from genetic datasets available in a subset of the cohort (n = 572) derived from Affymetrix(®) Genome-Wide Human SNP Array 5.0 and 1000 Genomes imputation from this array.

RESULTS

The candidate gene analysis revealed one variant from the DOPA decarboxylase gene, rs10499695, to be associated with poorer performance on a subset of Rey Auditory-Verbal Learning Task measuring retroactive interference (P = 0.001, β = -0.45). Secondary analysis of genome-wide and imputed data uncovered another DOPA decarboxylase variant, rs62445903, also associated with retroactive interference (P = 7.21 × 10(-7), β = 0.3). These data suggest a role for dopaminergic genes, specifically a gene involved in regulation of dopamine synthesis, in cognitive performance in type 2 diabetes.

A feasibility study exploring the role of pre-operative assessment when examining the mechanism of 'chemo-brain' in breast cancer patients

Background

Women receiving chemotherapy treatment for breast cancer may experience problems with their memory and attention (cognition), which is distressing and interferes with quality of life. It is unclear what causes or contributes to the problems they report: psychological distress, fatigue, coping style, or specific biological changes for example to pro inflammatory cytokines. Research shows however, that approximately a third of women with breast cancer perform poorly on tests of cognition before commencing chemotherapy. We aimed to examine the acceptability and relevance of pre-surgical assessments (bloods, brain imaging, cognitive tests and self-report questionnaires) when investigating the phenomenon of ‘chemo-brain’ and investigate whether inflammatory markers mediate chemotherapy-induced neuropsychological impairments in women treated for breast cancer.

Methods

Women with early stage breast cancer completed neuropsychological and quality of life assessments at T1 (pre-surgery), T2 (post-surgery before chemotherapy) and T3 (6 months later). Blood cytokine levels were measured at the same time points and brain imaging was performed at T1 and T3.

Results

In total, 14/58 women participated (8 chemotherapy, 6 non-chemotherapy). Prior to the start of chemotherapy a decline in cognitive performance compared to baseline was observed in one participant. At T3 women who received chemotherapy reported poorer quality of life and greater fatigue. Increases in soluble tumour necrosis factor receptor II (sTNFRII), interleukin-6, interleukin-10 and vascular endothelial growth factor occurred post chemotherapy only. Levels of sTNFRII were inversely correlated with grey matter volume (GMV) of the right posterior insula in both groups. At T3, the chemotherapy group displayed a greater reduction in GMV in the subgenual and dorsal anterior cingulate, and the inferior temporal gyrus.

Conclusions

Pre-operative recruitment to the study was challenging; however, the lack of significant changes in blood cytokine levels and neuropsychological tests at T2 implies that post surgery may be a valid baseline assessment, but this needs further investigation in a larger study. The preliminary results support the hypothesis that chemotherapy induced fatigue is mediated by a change in peripheral cytokine levels which could explain some symptoms of ‘chemo brain’ experienced by patients.

Changes in Neurocognitive Architecture in Patients with Obstructive Sleep Apnea Treated with Continuous Positive Airway Pressure

Background

Obstructive sleep apnea (OSA) is a chronic, multisystem disorder that has a bidirectional relationship with several major neurological disorders, including Alzheimer's dementia. Treatment with Continuous Positive Airway Pressure (CPAP) offers some protection from the effects of OSA, although it is still unclear which populations should be targeted, for how long, and what the effects of treatment are on different organ systems. We investigated whether cognitive improvements can be achieved as early as one month into CPAP treatment in patients with OSA.

Methods

55 patients (mean (SD) age: 47.6 (11.1) years) with newly diagnosed moderate–severe OSA (Oxygen Desaturation Index: 36.6 (25.2) events/hour; Epworth sleepiness score (ESS): 12.8 (4.9)) and 35 matched healthy volunteers were studied. All participants underwent neurocognitive testing, neuroimaging and polysomnography. Patients were randomized into parallel groups: CPAP with best supportive care (BSC), or BSC alone for one month, after which they were re-tested.

Findings

One month of CPAP with BSC resulted in a hypertrophic trend in the right thalamus [mean difference (%): 4.04, 95% CI: 1.47 to 6.61], which was absent in the BSC group [− 2.29, 95% CI: − 4.34 to − 0.24]. Significant improvement was also recorded in ESS, in the CPAP plus BSC group, following treatment [mean difference (%): − 27.97, 95% CI: − 36.75 to − 19.19 vs 2.46, 95% CI: − 5.23 to 10.15; P = 0.012], correlated to neuroplastic changes in brainstem (r = − 0.37; P = 0.05), and improvements in delayed logical memory scores [57.20, 95% CI: 42.94 to 71.46 vs 23.41, 95% CI: 17.17 to 29.65; P = 0.037].

Interpretation

One month of CPAP treatment can lead to adaptive alterations in the neurocognitive architecture that underlies the reduced sleepiness, and improved verbal episodic memory in patients with OSA. We propose that partial neural recovery occurs during short periods of treatment with CPAP.

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One month of CPAP treatment leads to adaptive alterations in the neuroanatomy and neurocognition in patients with OSA.

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Improvements in sleepiness and verbal episodic memory were demonstrable following only one month of treatment with CPAP.

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Our findings support the clinical rationale for the use of CPAP treatment to relieve sleepiness, even for a short duration.

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder that has been linked with dementia, stroke and increased risks of cardiovascular disease. Continuous positive airway pressure (CPAP) treatment has been shown to be effective in reducing sleepiness in moderate to severe OSA. However, the evidence for its use to reverse or slow the rate of cognitive decline is unclear. Our findings show that one month of CPAP treatment in patients with moderate to severe OSA leads to adaptive alterations in the brain networks associated with reduced sleepiness and improved memory.

Are We There Yet? Exploring the Impact of Translating Cognitive Tests for Dementia Using Mobile Technology in an Aging Population

This study examines implications of the expanded use of mobile platforms in testing cognitive function, and generates evidence on the impact utilizing mobile platforms for dementia screen. The Saint Louis University Mental State examination (SLUMS) was ported onto a computerized mobile application named the Cambridge University Pen to Digital Equivalence assessment (CUPDE). CUPDE was piloted and compared to the traditional pen and paper version, with a common comparator test for both groups. Sixty healthy participants (aged 50–79) completed both measurements. Differences were tested between overall outcomes, individual items, and relationship with the comparator. Significant differences in the overall scores between the two testing versions as well as within individual items were observed. Even when groups were matched by cognitive function and age, scores on SLUMS original version (M = 19.75, SD = 3) were significantly higher than those on CUPDE (M = 15.88, SD = 3.5), t₍₁₅₎ = 3.02, p < 0.01. Mobile platforms require the development of new normative standards, even when items can be directly translated. Furthermore, these must fit aging populations with significant variance in familiarity with mobile technology. Greater understanding of the interplay and related mechanisms between auditory and visual systems, which are not well understood yet in the context of mobile technologies, is mandatory.

Memory and executive functions in persons with type 2 diabetes: a meta-analysis

Literature suggests that persons with type 2 diabetes mellitus (T2DM) are at risk for cognitive impairment, hence dementia. Common domains reported to be affected in those with T2DM are memory and executive functions. The extent of influence of T2DM on these domains has varied among studies. A systematic review and meta-analysis was carried out to understand whether sub-domains contributed to the variations observed in published research. We searched 'PubMed', 'ScienceDirect', 'SciVerseHub', 'Psychinfo', 'Proquest' 'Ebsco' and 'J-gate Plus' databases for published studies on cognition and T2DM among persons aged 50 years and older. Memory, executive functions and processing speed domain and sub-domain scores were extracted; effect sizes (Cohen's d) were calculated and analysed. Eight hundred seventeen articles were found. After various levels of filtering, 15 articles met the inclusion criteria for quantitative analyses. The analyses indicated that in comparison to controls, persons with T2DM showed decrements in episodic memory (d = -0.51), logical memory (d = -0.24), sub-domain of executive functions which included phonemic fluency (d = -0.35) and cognitive flexibility (d = 0.52), and speed of processing (d = -0.22). We found no difference in the sub-domains of verbal short-term memory and working memory. The meta-analysis revealed a detrimental effect of T2DM on cognitive sub-domains, namely, episodic memory and cognitive flexibility. There was a trend for the logical memory, phonemic fluency and processing speed to be affected. The analysis indicates that T2DM is a detrimental factor on certain cognitive sub-domains, rendering the person vulnerable to subsequent dementia. Copyright © 2016 John Wiley & Sons, Ltd.

Clinical Pain and Neuropsychological Functioning in Parkinson's Disease: Are They Related?

Introduction. Pain is an important nonmotor symptom of Parkinson's disease (PD). Brain areas such as the hippocampus and the prefrontal cortex play an important role in the processing of pain. Since these brain areas are also involved in cognitive functioning, for example, episodic memory and executive functions, respectively, we examined whether a relationship exists between cognitive functioning and spontaneous pain in PD. Methods. Forty-eight patients with PD and 57 controls participated. Cognitive functioning was measured by a comprehensive battery of neuropsychological tests. Both the sensory-discriminative aspect and the motivational-affective aspect of pain were assessed. Multiple linear regression analyses were performed to assess a relation between cognition and pain. Results. Cognition was related to neither the sensory nor the affective aspect of pain in our sample of PD patients. Variance in pain measures was primarily explained by symptoms of depression and anxiety. Discussion. The difference between the affective and the sensory aspect of pain might be due to the neuropathology of PD, which is mainly present in areas processing the affective aspect of pain. Pain treatment might improve when mood is taken into account. We provide several explanations for the lack of an association between pain and cognition.

Effect of Pharmacological Interventions on the Fronto-Cingulo-Parietal Cognitive Control Network in Psychiatric Disorders: A Transdiagnostic Systematic Review of fMRI Studies

Executive function deficits, such as working memory, decision-making, and attention problems, are a common feature of several psychiatric disorders for which no satisfactory treatment exists. Here, we transdiagnostically investigate the effects of pharmacological interventions (other than methylphenidate) on the fronto-cingulo-parietal cognitive control network, in order to identify functional brain markers for future procognitive pharmacological interventions. Twenty-nine manuscripts investigated the effect of pharmacological treatment on executive function-related brain correlates in psychotic disorders (n = 11), depression (n = 4), bipolar disorder (n = 4), ADHD (n = 4), OCD (n = 2), smoking dependence (n = 2), alcohol dependence (n = 1), and pathological gambling (n = 1). In terms of impact on the fronto-cingulo-parietal network, the preliminary evidence for catechol-O-methyl-transferase inhibitors, nicotinic receptor agonists, and atomoxetine was relatively consistent, the data for atypical antipsychotics and anticonvulsants moderate, and interpretation of the data for antidepressants was hampered by the employed study designs. Increased activity in task-relevant areas and decreased activity in task-irrelevant areas were the most common transdiagnostic effects of pharmacological treatment. These markers showed good positive and moderate negative predictive value. It is concluded that fronto-cingulo-parietal activity changes can serve as a marker for future procognitive interventions. Future recommendations include the use of randomized double-blind designs and selective cholinergic and glutamatergic compounds.

Task-dependent and polarity-specific effects of prefrontal transcranial direct current stimulation on cortical activation during word fluency

Targeted modulation of cortical functions by non-invasive brain stimulation is widely used for the investigation of the neurophysiological signatures of executive functions and put forward as a potential specific treatment for its disorders. To further investigate the underlying mechanisms, we performed two experiments involving 46 subjects that performed a semantic and a phonological verbal fluency task (VFT) as well as a simple speech-production task after application of 1mA anodal or cathodal transcranial direct current stimulation (tDCS) to the left inferior frontal gyrus (IFG). Brain activation was measured by functional near-infrared spectroscopy (fNIRS) during task performance. Neither preceding anodal nor cathodal tDCS was found to modulate VFT performance of either difficulty. However, preconditioning with anodal tDCS increased brain activity during the VFT whereas a trendwise decrease of activation was found after cathodal stimulation. Notably, this difference was not found with simple speech production. These findings support the notion of a polarity-specific malleability of neuronal network activity underlying speech production by tDCS. Most importantly, the task-specificity of the modulatory effect observed after the end of stimulation demonstrates lasting neurophysiological effects of tDCS that are reflected in modifications of cortical excitability by challenging cognitive tasks.

Development and implementation of Persian test of Elderly for Assessment of Cognition and Executive function (PEACE)

Introduction

A considerable segment of the elderly population in Iran is illiterate, and it seems the existing neuropsychological screening tests are not very useful for detecting dementia in illiterate participants. The purpose of this study was to develop and validate a tool called Persian test of Elderly for Assessment of Cognition and Executive function (PEACE) for detecting dementia in both illiterate and literate participants.

Methods

First, in order to design some of the cognitive aspects of the PEACE assay, we considered other prevalent neuropsychological instruments, such as the General Practitioner assessment of Cognition (GPCOG), Functional Assessment Staging (FAST), Mini Mental State Examination (MMSE), and Wechsler Memory scale. The other domains of PEACE were designed according to our clinical proficiencies and the culture of the society. In the next step, the participants were classified into three distinct groups, i.e., the control group (n=33), the Mild Cognitive Impairment (MCI) group (n=30), and the Alzheimer’s group (n=38). All of the participants in each group were divided according to their educational level, i.e., illiterate, semi-literate, and literate.

Results

We developed PEACE consisting of 14 items, each of which represents a specific cognitive function, with a maximum score of 91. The 14 items are Orientation, Praxis, Attention and Concentration, Attention and Calculation, Memory, Similarity, Abstract Thinking, General Information, Language, Judgment, Gnosis, Planning (Sequencing), Problem Solving, and Animal Naming. PEACE scores are highly correlated with those of the MMSE (r=0.78). The optimal cut-off point of PEACE chosen for diagnosis of Alzheimer’s disease was 67.5 (sensitivity: 75.8%, specificity: 97.4%). The PEACE scores showed a significant difference between Participants with Alzheimer’s disease and the control group (p=0.0000) and the MCI group (p=0.003). In addition, there was no significant difference between illiterate and literate participants in the Alzheimer’s group. However, the PEACE scores differed significantly (p=0.0000) between illiterate and literate participants in the control group.

Conclusion

The PEACE addresses the limitations of existing tests and is appropriate for use in countries that have high rates of illiteracy. It is a valid screening mechanism for the detection of dementia in both illiterate and literate participants.

Improvement in executive subfunctions following cerebrospinal fluid tap test identifies idiopathic normal pressure hydrocephalus from its mimics

BACKGROUND AND PURPOSE

Patients with idiopathic normal pressure hydrocephalus (iNPH) present cognitive deficits that overlap with other neurological conditions such as Parkinson's disease or vascular dementia, therefore mimicking iNPH. This prospective study aimed to compare cognitive performances between iNPH and iNPH mimics before and after cerebrospinal fluid (CSF) tapping.

METHODS

A total of 57 patients with suspicion of iNPH (75.84 ± 6.42 years; 39% female) were included in this study (37 iNPH and 20 iNPH mimics). Neuropsychological assessments were performed before and 24 h after CSF tapping of 40 ml. Multivariate logistic regressions were used to examine the association between iNPH and cognitive functions, adjusted for age, education, baseline cognitive assessment and disease duration.

RESULTS

Both groups presented the same baseline cognitive performances. After CSF tapping, iNPH patients improved their semantic (P = 0.001) and phonemic verbal fluencies (P = 0.001), whereas iNPH mimics presented similar performances to before CSF tapping. The phonemic verbal fluency (odds ratio 1.43, 95% confidence interval 1.05; 1.96) and the Color Trails Test (odds ratio 0.10, 95% confidence interval 0.01; 0.76) improvements were the two discriminative cognitive tests that identified iNPH from iNPH mimics.

CONCLUSION

Improvement in executive subfunctions after CSF tapping identified iNPH patients from other neurological conditions that mimic iNPH. These findings respond to clinical issues encountered on a daily basis and would improve the diagnostic process of iNPH.

Interacting effects of age and time of day on verbal fluency performance and intraindividual variability

We explored the effects of age and time of day (TOD) on verbal fluency ability with respect to performance level and intraindividual variability (IIV). Verbal fluency, which involves complex cognitive operations, was examined in 20 older (mean age = 72.8 years) and 20 younger (mean age = 24.2 years) adults with test start time alternating between morning and evening across four days. Older adults generated more words in the morning and younger adults more in the evening, corresponding with self-report peak TOD. Age by TOD interactions were also observed across fluency tasks on the number of switches among subcategory exemplars during word generation and on the IIV observed in switching behavior. Older adults exhibited greater variability in switching in the evening than in the morning, whereas younger adults showed the opposite pattern. These findings demonstrate that processes involving energization (initiating and sustaining) and attentional control may be particularly sensitive to age differences in TOD influences on cognition.

Evaluation of cognitive function in bipolar disorder using the Brief Assessment of Cognition in Affective Disorders (BAC-A)

BACKGROUND

Although cognitive impairment is a core feature of bipolar disorder (BD) there is no instrument of choice for the assessment of bipolar patients. The aim of this study is to assess cognitive performance using the Brief Assessment of Cognition in Affective Disorders (BAC-A), a comprehensive test battery developed specifically for BD, and determine its suitability to estimate global functioning.

METHODS

The BAC-A was administered to 93 BD patients (M ± S.E: 35.18 ± 1.39 years) and 56 healthy controls (HC - M ± S.E: 36.17 ± 1.91 years). The scores of the BAC-A were combined in eight summary scores: visuomotor, immediate affective and non-affective memory, verbal fluency, delayed affective and non-affective memory, inhibition, and problem solving. Post hoc analyses were performed on subtests of the summary scores found to be significantly different between BD patients and HC. Correlational analyses explored the association between the Global Assessment of Functioning (GAF) score and cognitive functioning.

RESULTS

Compared to HC, BD patients showed a significant impairment in short-term non-affective memory and verbal fluency. Poorer performance in verbal memory and verbal fluency summary scores correlated positively with reduced GAF.

CONCLUSIONS

Our results are consistent with previous reports of verbal memory and verbal fluency impairment in BD. The deficits in short-term memory and semantic fluency may indicate inefficient learning strategies and/or difficulties in retrieving information. The BAC-A could be used to estimate global functioning in BD patients.

Feasibility of a mindfulness-based intervention to address youth issues in Vietnam

Youth problems including risky sex, drug use, violence and mental health issues are on the rise in Vietnam. Mindfulness is proposed as one way to address unskillful responses to stress that give rise to these behavioral and psychosocial issues in Vietnam. This study explores the feasibility of a mindfulness program for adolescents and young adults in a central city in Vietnam. The mindfulness-based intervention was comprised 1-h daily session over 3 weeks that was conducted at two different sites, one with handicapped adolescents/young adults at the Vocational School for Handicapped and the other with at-risk youth at a semi-private high school. Forty-two Vietnamese youth participants and five Vietnamese teachers/facilitators who were trained in the mindfulness program provided personal reflections of their experiences. Analyses of the qualitative data suggest that mindfulness was enthusiastically received and accepted by both youth and teachers. There is strong indication that mindfulness is promising as a prevention strategy to help with stress and to build important life skills among Vietnamese youth.