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

Evaluating the factor structure of the Dutch individual differences in language skills (IDLaS-NL) test battery

Individual differences in using language are prevalent in our daily lives. Language skills are often assessed in vocational (predominantly written language) and diagnostic contexts. Not much is known, however, about individual differences in spoken language skills. The lack of research is in part due to the lack of suitable test instruments. We introduce the Individual Differences in Language Skills (IDLaS-NL) test battery, a set of 31 behavioural tests that can be used to capture variability in language and relevant general cognitive skills in adult speakers of Dutch. The battery was designed to measure word and sentence production and comprehension skills, linguistic knowledge, nonverbal processing speed, working memory, and nonverbal reasoning. The present article outlines the structure of the battery, describes the materials and procedure of each test, and evaluates the battery's factor structure based on the results of a sample of 748 Dutch adults, aged between 18 and 30 years, most of them students. The analyses demonstrate that the battery has good construct validity and can be reliably administered both in the lab and via the internet. We therefore recommend the battery as a valuable new tool to assess individual differences in language knowledge and skills; this future work may include linking language skills to other aspects of human cognition and life outcomes.

The impact of gestational age on executive function in infancy and early-to-middle childhood following preterm birth: a systematic review

Lower gestational age (GA) is a risk factor for cognitive and developmental concerns following preterm birth. However, its impact on executive function (EF) is unclear based on conflicting conclusions across the literature. Moreover, as children below 4 years have largely been neglected from previous reviews, the impact of GA on EF within this early developmental period remains unclear. Hence, this systematic review investigated the impact of GA on EF following preterm birth in infancy and early-to-middle childhood. PubMed, Web of Science, and PsycInfo were searched for articles investigating the impact of GA on EF (inhibition, working memory, shifting) in preterm-born (<37 week gestation) and term-born participants aged 0-10 years. Eighteen studies were included. Most of the studies (n = 10) found no significant association between EF and GA. However, several limitations hindered conclusions to be drawn about the strength of this interpretation. Examples include inconsistencies in the theoretical underpinnings and operationalisations of EF, discrepancies in the reporting and measurement of GA, recruitment biases, and a paucity of infant or longitudinal studies available. Consequently, these issues may have contributed to inconsistent or null findings, and they must be addressed in future research to better clarify the impact of GA on EF in preterm-born infants and children.

Verbal Fluency Selectively Predicts Survival in Old and Very Old Age

Intelligence is known to predict survival, but it remains unclear whether cognitive abilities differ in their relationship to survival in old age. We analyzed longitudinal data of 516 healthy adults (age: M = 84.92 years, SD = 8.66 years at Wave 1) from the Berlin Aging Study (Germany) on nine tasks of perceptual speed, episodic memory, verbal fluency, and verbal knowledge, and a general composite intelligence score. There were eight waves, with up to 18 years of follow-up; all participants were deceased by the time of analysis. We used a joint multivariate longitudinal survival model to estimate the unique contribution of each cognitive ability in terms of true (i.e., error-free) current value and current rate of change when predicting survival. Additional survival covariates included age at first occasion, sex, sociobiographical status, and suspected dementia. Only the two verbal-fluency measures were uniquely predictive of mortality risk. Thus, verbal fluency showed more salient associations with mortality risk than did measures of perceptual speed, episodic memory, and verbal knowledge.

Tablet- and Group-Based Multicomponent Cognitive Stimulation for Older Adults With Mild Cognitive Impairment: Single-Group Pilot Study and Protocol for Randomized Controlled Trial

BACKGROUND

Cognitive stimulation therapy is a group-based psychological treatment for people with dementia as well as those with mild cognitive impairment (MCI) and is shown to improve both cognition and quality of life. Previous studies have indicated the potential to benefit from the use of technological devices in group interventions.

OBJECTIVE

The pilot study aimed to assess the effectiveness of a tablet- and group-based multicomponent cognitive stimulation therapy (MCST) for enhancing cognitive functions among older adults with MCI. The following study aims to report the protocol for a trial evaluating whether the MCST program is affecting individuals with MCI.

METHODS

In the first study, 30 individuals with MCI participated in 10 sessions of the tablet- and group-based MCST group. A subsequent protocol study will compare tablet-based MCST, tablet-based cognitive stimulation therapy, and control groups among 93 individuals with MCI. All participants will be recruited from older adults living in semiurban communities. Intervention groups will be facilitated by trained therapists, nurses, or psychologists. The study will be assessed by a pre- and posttest evaluation, including computer-based neuropsychological tests and electroencephalography assessment. The effects of several indicators, such as cognitive functions, behavioral, and emotional, will be analyzed as being indexed by their neurophysiological data.

RESULTS

The pilot study showed significant cognitive improvement (P<.001), reduced depression (P=.002), and decreased state anxiety (P=.001) post intervention. Quality of life remained unchanged (P=.18). The randomized controlled trial study was funded in March 2023. Enrolling began in August 2023 and was completed in December 2023. The data analysis was started, and the results are expected to be published by mid- to late-2025.

CONCLUSIONS

The study is the first tablet-group-based MCST for older adults with MCI in middle-income countries. It will provide deeper insight into participants' neuropsychological data, thus identifying specific processes underlying physiologically measured positive outcomes. Furthermore, the project will deliver solid and integrative results to mental health professionals in terms of knowledge and guidance for implementing the tablet- and group-based MCST in people with MCI.

TRIAL REGISTRATION

Thai Clinical Trials Registry TCTR20230829004; https://tinyurl.com/3wuaue3e.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/64465.

Executive function deficit in patients with long COVID syndrome: A systematic review

Background

Post-COVID-19 condition (Long COVID) refers to a condition in which patients endure persistent symptoms for more than 12 weeks, typically occurring at least 3 months after the onset of Coronavirus disease 2019 (COVID-19) infection. It occurs when a constellation of symptoms persists following the initial illness, and this may obstruct a daily routine and impose difficulty in life. Therefore, this study aimed to systematically review published articles assessing the neurocognitive profile of long COVID patients, with a specific emphasis on executive function (EF), and to determine the correlation between EF deficits and brain alterations through the utilisation of neuroimaging modalities.

Methods

A thorough search was conducted using the PubMed/MEDLINE and Web of Science online databases following the PICOS and PRISMA 2020 guidelines. All included studies were deemed to be of high quality according to the Newcastle-Ottawa Scale (NOS).

Results

A total of 31 out of 3268 articles were included in the present study. The main outcome is the proportion of individuals with cognitive deficits, particularly in the EF domain, as detected by neuropsychological assessments. The present study also revealed that EF deficits in long COVID patients are correlated with disruptions in the frontal and cerebellar regions, affecting processes such as nonverbal reasoning, executive aspects of language, and recall. This consistent disturbance also emphasised the correlation between EF deficits and brain alterations in patients with long COVID.

Conclusion

The present study highlights the importance of evaluating EF deficits in long COVID patients. This insight has the potential to improve future treatments and interventions.

Effects of Dance-Based Aerobic Training on Frailty and Cognitive Function in Older Adults with Mild Cognitive Impairment: A Randomized Controlled Trial

Background/Objectives: The purpose of this study has been to evaluate the effects of a dance-based aerobic training program on frailty, cognitive impairment, executive functions, and verbal fluency in older adults with mild cognitive impairment. Methods: Randomized clinical trial, whose sample was made up of 92 older adults, of which 47 performed rhythmic physical activity for 12 weeks. Data on frailty were collected through FRAIL, cognitive function through the Mini-Mental State Examination (MMSE), cognitive impairment through The Montreal Cognitive Assessment (MoCA), verbal fluency using the Isaac test, and executive functions with the Trail Making Test (TMT). All variables were measured before and after the intervention by an independent researcher blinded to the treatment. Results: Participants in the experimental group showed statistically significant improvements in frailty (Cohen's d = 0.60), cognitive function (Cohen's d = 0.98), cognitive impairment (Cohen's d = 1.22), verbal fluency (Cohen's d = 0.61) and executive functions (Cohen's d = 0.64). Conclusions: This study demonstrated that a 12-week dance-based aerobic training program can significantly reduce frailty and improve cognitive abilities in older adults with mild cognitive impairment. These improvements suggest that the intervention is not only effective in terms of physical health, but also in promoting mental health and general well-being.

Bilingual language control during single-language production: does relocation to a new linguistic environment change it?

A bilingual's two languages are simultaneously active and competing for selection, even when only one language is used. To manage this competition, bilinguals apply language control. We examined how bilinguals apply control across two single-language tasks and how this language control might adapt to the language environment bilinguals live in. We conducted a longitudinal study with Mandarin-English bilinguals who moved from China to the UK and a control group staying in China. Participants completed a picture-naming task and a verbal-fluency task twice, approximately seven months apart. We examined language order effects by comparing performance in each language when it was used first versus after the other language. While the L2 benefited from being used second, L1 performance benefited less or even deteriorated after L2 use. This suggests bilinguals proactively applied language control, especially during L2 use, to manage the anticipated language competition from the L1. However, these effects did not change after relocation to the UK, nor did they differ between the groups. This suggests that while language control is a core part of language production, the language environment a bilingual lives in might not have a defining impact on the exact way this language control is applied.

Automated acoustic voice screening techniques for comorbid depression and anxiety disorders

Anxiety disorders (AD) and major depressive disorders (MDD) are growing in prevalence, yet many people suffering from these disorders remain undiagnosed due to known perceptual, attitudinal, and structural barriers. Methods, tools, and technologies that can overcome these barriers and improve screening rates are needed. Tools based on automated analysis of acoustic voice could help bridge this gap. Comorbid AD/MDD presents additional challenges since some effects of AD and MDD oppose one another. Here, acoustic models that use acoustic and phonemic data from verbal fluency tests to discern the presence of comorbid AD/MDD are presented, with the best results of F1 = 0.83.

Kidney Function, Cognitive Impairment, and Trajectories: A Longitudinal Biracial Study

BACKGROUND

Chronic kidney disease (CKD) is associated with incident cognitive impairment (ICI) and disproportionately affects older adults and Black persons.

OBJECTIVE

To determine (1) whether age or race differences exist in the association of CKD and ICI and (2) whether cognitive trajectories differ in people with and without CKD.

DESIGN

Nationwide cohort study.

PARTICIPANTS

A total of 22,435 Black and White adults age ≥ 45 years without baseline cognitive impairment.

MEASUREMENTS

Creatinine-cystatin C-based eGFR and albumin-to-creatinine ratio (ACR). Six-item screener (SIS) of global cognition every 6 months, three cognitive domain tests (memory, semantic, and letter fluencies) every 2 years for 10 years. Logistic regression for risk of CI and latent growth curve models for trajectory analysis.

RESULTS

Participants were 56% female, 37% Black, 56% hypertensive, and 19% had diabetes. Overall, 13% (n = 2959) developed ICI over 10 years. In mid-life (age 45- < 65), the OR (95% CI) of ICI for eGFR < 45 vs eGFR ≥ 90 was 1.9 (1.2, 3.0); in late-life (≥ 65), the OR was 0.9 (0.7, 1.1), p interaction < 0.001. For ACR > 300 vs ACR < 10, in mid-life and late-life, the ORs were 1.6 (1.0, 2.6) and 1.0 (0.7, 1.4), p interaction 0.02. Compared to those with eGFR ≥ 60, eGFR < 60 was associated with lower initial cognitive domains scores, worse in mid-life than late-life, but the slopes did not differ. Compared to ACR < 30, ACR ≥ 30 had lower initial cognitive domain scores, which were similar in mid and late-life, and a steeper decline for memory scores. No differences by race were observed.

CONCLUSIONS

Kidney disease was more strongly linked to cognitive impairment in mid-life than in late-life. Albuminuria was associated with steeper decline in memory function, especially in mid-life.

PRIMARY FUNDING SOURCE

NIGMS.

Item-Level Analysis of Category Fluency Test Performance: A Systematic Review and Meta-Analysis of Studies of Normal and Neurologically Abnormal Ageing

While Category Fluency (CF) is widely used to help profile semantic memory, item-level scoring (ILS) approaches to this test have been proposed to obtain indices that are less influenced by non-semantic supportive functions. We systematically reviewed the literature to test the hypotheses that (1) compared with healthy adults, individuals with a clinical diagnosis suggestive of neurodegeneration generate words of lower semantic complexity; (2) compared with young adults, older adults generate words of higher semantic complexity. We searched six databases (date of search: 8 December 2023) for studies that relied on CF and ILS methods, in normal ageing and in age-associated neurodegeneration. Thirty-four studies were shortlisted: 27 on neurodegenerative conditions; 7 on normal ageing. Risk of bias was evaluated via a published checklist. Data were presented via qualitative synthesis. Most studies reported words of lower semantic complexity in relation to at least one item-level feature in individuals with mild cognitive impairment (MCI), Alzheimer's dementia (AD), and other neurodegenerative diseases. Post-hoc meta-analyses focussing on the MCI/AD continuum confirmed an effect on words' frequency (385 MCI/AD individuals and 350 controls; Hedges's G = 0.59) and age-of-acquisition (193 MCI/AD individuals and 161 controls; Hedges's G =  - 1.51). Studies on normal ageing, conversely, failed to demonstrate any overall effect. Most studies on MCI and AD have not relied on neurobiological diagnostic criteria. Moreover, only a small number of studies analysed ILS controlling for quantitative CF performance. Despite these two limitations, this study suggests that ILS can contribute to an in-depth characterisation of semantic memory in neurological ageing.

Functional Connectivity and MRI Radiomics Biomarkers of Cognitive and Brain Reserve in Post-Stroke Cognitive Impairment Prediction-A Study Protocol

Acute ischemic stroke (AIS) is frequently associated with long-term post-stroke cognitive impairment (PSCI) and dementia. While the mechanisms behind PSCI are not fully understood, the brain and cognitive reserve concepts are topics of ongoing research exploring the ability of individuals to maintain intact cognitive performance despite ischemic injuries. Brain reserve refers to the brain's structural capacity to compensate for damage, with markers like hippocampal atrophy and white matter lesions indicating reduced reserve. Cognitive reserve involves the brain's ability to optimize performance and use alternative networks to maintain function. Advanced methods of MRI and EEG processing may better assess brain reserve and cognitive reserve, with emerging predictive models integrating these measures to improve PSCI prediction. This article provides the design of a hospital-based study investigating the predictive role of functional connectivity and MRI radiomics in assessing PSCI occurrence one year after AIS. One hundred forty-four patients will be enrolled following strict inclusion/exclusion criteria. The patients will undergo comprehensive assessments, including neuropsychological testing, brain MRI, and quantitative EEG (QEEG), across four visits over a year. The primary outcome will be PSCI occurrence, and it will be assessed at six and twelve months after AIS. Secondary outcomes will include PSCI severity, recurrent AIS, and mortality. Statistical analyses will be performed to identify predictive factors using Cox proportional hazards models, and predictive models based on QEEG, MRI radiomics, and clinical data will be built. Early detection of AIS patients prone to developing PSCI might outline more effective therapeutic approaches, reducing the social and economic burden of ischemic stroke.

No Relation Between Cognitive Impairment, Physical Disability and Serum Biomarkers in a Cohort of Progressive Multiple Sclerosis Patients

Despite significant efforts, there is still an existing need to identify diagnostic tools that would enable fast and reliable detection of the progressive stage of multiple sclerosis (MS) and help in monitoring the disease course and/or treatment effects. The aim of this prospective study in a group of people with progressive MS was to determine whether changes in the levels of selected serum biomarkers and in cognitive function may predict disease progression, and therefore refine the decision-making process in the evaluation of MS patients. Forty two (42) patients with progressive MS completed all the study procedures; the mean duration of follow-up was 12.97 months. During the observation period, serum concentration of chitinase-3 like-protein-1 (CHI3L1/YKL-40) decreased significantly in the whole study group (from 4034.95 ± 262.62 to 2866.43 ± 173.37; p = 0.0005), as well as in subgroups of people with secondary progressive and primary progressive MS (SPMS: from 3693.81 ± 388.68 to 2542.76 ± 256.59; p = 0.0207; and PPMS: from 4376.09 ± 353.27 to 3190.09 ± 233.22; p = 0.0089, respectively). A significant worsening of Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) scores was detected in the whole study group (from 1.18 ± 0.14 to 1.34 ± 0.15; p = 0.0331) as well as in the PPMS subgroup (from 1.04 ± 0.18 to 1.26 ± 0.20; p = 0.0216). No correlations between the analyzed molecular parameters or the results of neuropsychological tests and physical disability were observed. In conclusion, an emphasis should be placed on furthering the search for multimodal biomarkers of disease progression, especially in the PMS population, based on simultaneous analysis of several factors, such as blood biomarkers and cognitive profiles.

Language and Ageing in Adults With Down Syndrome: An Analysis of Receptive and Expressive Language Measures

BACKGROUND

The evidence on the effect of age on the receptive and expressive language skills of individuals with Down syndrome is inconclusive. Recent research highlights the relevance of having tools to detect age-related changes in language skills.

METHOD

Data were collected on 45 adults with Down syndrome. All were assessed with the Peabody test, token test, verbal fluency tasks and an expressive language sample.

RESULTS

Scores on token and Peabody showed a decline in older adults, whereas no significant effect of age was observed for expressive language measures. A quadratic regression confirmed the association between age and receptive language measures. Highly significant associations were also found between the performance on receptive and expressive language measures.

CONCLUSIONS

Receptive language skills are more age-sensitive than the expressive language skills. In addition to expressive language skills, receptive language skills should be measured because they show age associated changes not observed in expressive language.

fNIRS Classification of Adults with ADHD Enhanced by Feature Selection

Adult attention deficit hyperactivity disorder (ADHD), a prevalent psychiatric disorder, significantly impacts social, academic, and occupational functioning. However, it has been relatively less prioritized compared to childhood ADHD. This study employed a functional near-infrared spectroscopy (fNIRS) during verbal fluency tasks in conjunction with machine learning (ML) techniques to differentiate between healthy controls (N=75) and ADHD individuals (N=120). Efficient feature selection in high-dimensional fNIRS datasets is crucial for improving accuracy. To address this, we propose a hybrid feature selection method that combines a wrapper-based and embedded approach, termed Bayesian-Tuned Ridge RFECV (BTR-RFECV). The proposed method facilitated streamlined feature selection and hyperparameter tuning in high-dimensional data, thereby reducing the number of features while enhancing accuracy. HbO features from the combined frontal and temporal regions were key, with the models achieving precision (89.89%), recall (89.74%), F-1 score (89.66%), accuracy (89.74%), MCC (78.36%), and GDR (88.45%). The outcomes of this study highlight the promising potential of combining fNIRS with ML as diagnostic tools in clinical settings, offering a pathway to significantly reduce manual intervention.

Individual differences in online research: Comparing lab-based and online administration of a psycholinguistic battery of linguistic and domain-general skills

Experimental psychologists and psycholinguists increasingly turn to online research for data collection due to the ease of sampling many diverse participants in parallel. Online research has shown promising validity and consistency, but is it suitable for all paradigms? Specifically, is it reliable enough for individual differences research? The current paper reports performance on 15 tasks from a psycholinguistic individual differences battery, including timed and untimed assessments of linguistic abilities, as well as domain-general skills. From a demographically homogenous sample of young Dutch people, 149 participants participated in the lab study, and 515 participated online. Our results indicate that there is no reason to assume that participants tested online will underperform compared to lab-based testing, though they highlight the importance of motivation and the potential for external help (e.g., through looking up answers) online. Overall, we conclude that there is reason for optimism in the future of online research into individual differences.

Low income, being without employment, and living alone: how they are associated with cognitive functioning-Results from the German national cohort (NAKO)

Aim was to investigate to what extent cognitive functioning differs by three socioeconomic conditions: low income, being without employment, and living alone. A total of N = 158,144 participants of the population-based German National Cohort (NAKO) provided data on socioeconomic conditions and completed cognitive tests. Multivariable confounder-adjusted regression analyses indicated that cognitive functioning was lower in those with low income (b = -0.21) compared to not having low income, living alone (b = -0.04) compared to not living alone, and being without employment (b = -0.09) compared to being employed. An interaction with age indicated that the difference in cognitive functioning was getting larger with age between the income groups and living alone status groups. Accordingly, the three conditions appear independently associated with poorer cognitive functioning. Pathways of how cognitive health in this population group can be improved need to be explored.

Investigating the cognitive architecture of verbal fluency: evidence from an interference design on 487 controls

Introduction

Numerous studies have explored the linguistic and executive processes underlying verbal fluency using association designs, which provide limited evidence. To assess the validity of our model, we aimed to refine the cognitive architecture of verbal fluency using an interference design.

Methods

A total of 487 healthy participants performed letter and semantic fluency tests under the single condition and dual conditions while concurrently performing a secondary task that interferes with speed, semantics, phonology, or flexibility. We examined the effect of such interference on fluency indices including correct responses, clustering, switching, and time course.

Results

(1) All secondary tasks decreased fluency (p < 0.0001, all), (2) including a simple concurrent task that solely engages the attentional activation system (i.e., speed interference) and (3) a complex concurrent task that affects the ability to alternate (i.e., flexibility interference). (4) Linguistic secondary tasks (which engage phonological and semantic processes, in addition to attention) led to a greater decrease in fluency than speed interference (p < 0.0001), (5) with a more pronounced decrease in semantic fluency induced by semantic interference (p < 0.0001), and (6) the highest decrease in all types of fluency induced by phonological interference (p < 0.0001). In terms of derived indices, (7) speed interference decreased switching without affecting clustering (p < 0.0001) and (8) phonological interference mainly affected the first time interval, whereas speed and flexibility interference primarily affected the last time interval (p < 0.0001, all).

Discussion

These results, based on an interference design, indicate that letter and semantic fluency involve output lexico-phonological and semantic processes with which the strategic search process interacts, as well as an attentional component necessary to accelerate overall processing. These results also highlight interactions with other executive processes, such as those involved in stimulus dimension alternation, which require further analysis. They support our model and provide information concerning derived indices. The commonly claimed associations of executive function with switching and of semantic ability with clustering are only partially supported by our results. Finally, word production appears to be modulated by different cognitive processes over time, with a prominence of the phonological output lexicon in early production and more demanding processing (i.e., executive functioning) in late production.

Leveraging relatedness-based measures in people with language disorders: A scoping review

Understanding lexico-semantic processing is crucial for dissecting the complexities of language and its disorders. Relatedness-based measures, or those which investigate the degree of relatedness in meaning between either task items or items produced by participants, offer the opportunity to harness novel computational and analytical techniques from cognitive network science. Recognizing the need to deepen our understanding of lexico-semantic deficits through diverse experimental and analytical approaches, this review explores the use of such measures in research into language disorders. A comprehensive search of four electronic databases covering publications from the last 11 years (October 2013-September 2024) identified 38 original experimental studies employing relatedness-based measures in populations with language disorders or other neurological conditions. Articles were examined for the types of tasks used, populations studied, item selection methods and analytical approaches. The predominant use of category fluency tasks emerged across studies, with a notable absence of relatedness judgement tasks or comparable paradigms. Commonly discussed populations included individuals with post-stroke aphasia, mild cognitive impairment and schizophrenia. Analytical methods varied significantly, ranging from more traditional approaches of clustering and switching to more sophisticated computational techniques. Despite the evident utility of category fluency tasks in research and clinical settings, the review underscores a critical need to diversify experimental paradigms and probe lexico-semantic processing in a more multifaceted manner. A broadened approach in future language disorder research should incorporate innovative analytical techniques, investigations of neural correlates and a wider array of tasks employing relatedness-based measures already present in healthy populations.

Brain Abnormalities During Self-Referential Task in Subthreshold Depression: A Near-Infrared Spectroscopy Study

Background and aim Subthreshold depression is a potential risk factor for major depressive disorder. Although the neurobiological mechanism underlying major depressive disorder is well-established, the mechanism underlying subthreshold depression has not yet been fully elucidated. We investigated the characteristics of brain abnormalities in participants with subthreshold depression using near-infrared spectroscopy (NIRS) owing to its portability. Methods A total of 53 college students were recruited, and all participants performed three tasks: self-referential task (SRT), verbal fluency task (VFT), and category fluency task (CFT). Hemodynamic changes in the prefrontal cortex (PFC) during the tasks were also measured using NIRS. A generalized linear model was employed for the NIRS data analysis. Subsequently, we evaluated the relationship between depressive severity and NIRS data during task performance. Results Our analysis revealed a positive correlation between hemodynamic changes in the right PFC during the SRT and depression severity (SRTL_coeff: 0.12), suggesting that increased activation in this region may be associated with higher levels of depressive severity. In contrast, hemodynamic changes in the left PFC during the SRT did not significantly influence the severity of depression. Additionally, hemodynamic changes during the VFT and CFT did not significantly influence the severity of depression. Conclusions Hyperactivation of the right PFC, which is a characteristic of subthreshold depression, may cause a negative bias, leading to high sensitivity to negative stimuli. These results provide novel insights into the neural mechanism of subthreshold depression and highlight the utility of NIRS for evaluating brain function related to negative bias in the right PFC.

Changes in Response Inhibition, Visual Anticipation and Verbal Fluency During Vagus Nerve Stimulation Therapy in Patients With Drug-Resistant Epilepsy

BACKGROUND

The effect of vagus nerve stimulation (VNS) on cognitive domain of attention and executive functions (AEFs) has not been extensively researched. This study was set up to investigate performance variability on cognitive tests assessing AEFs in drug-resistant epilepsy (DRE) patients receiving VNS therapy during a follow-up of up to 5 years.

METHODS

Thirty-three DRE patients were assessed with the interference, maze, and written verbal fluency tests as a part of EpiTrack screening before and after VNS implantation through repeated follow-ups according to the clinical VNS protocol. A linear mixed-effects model was used to analyse changes in test scores.

RESULTS

Maze performance improved significantly by an average of 0.20 s per month (95% confidence interval (CI): -0.365 to -0.041; p = 0.014). Interference performance improved by an average of 0.05 s per month (p = 0.207) and number of words increased by an average of 0.03 words per month (p = 0.079) on the verbal fluency test. On the maze test, patients with psychiatric comorbidities improved the most (0.52 s/month, p = 0.001), while on the interference test, patients with frontal lobe epilepsy (FLE), those taking 1-2 antiseizure medications (ASMs) and patients with focal to bilateral tonic-clonic seizures improved the most (0.14 s/month, p = 0.005; 0.14 s/month, p = 0.033 and 0.16 s/month, p = 0.087, respectively). For verbal fluency, no clinically meaningful improvement was noted in any of the groups.

CONCLUSION

During the follow-up, maze performance markedly improved, while performance on the interference and verbal fluency tasks remained relatively stable at the group level. Accordingly, visual anticipation and planning improved during VNS therapy whereas response inhibition was unchanged at the group level despite significant enhancements in patients with FLE and those taking 1-2 ASM. Furthermore, the presence of psychiatric comorbidities correlated with even greater improvement on maze performance.

Examining heterogeneity in dementia using data-driven unsupervised clustering of cognitive profiles

Dementia is characterized by a decline in memory and thinking that is significant enough to impair function in activities of daily living. Patients seen in dementia specialty clinics are highly heterogenous with a variety of different symptoms that progress at different rates. Recent research has focused on finding data-driven subtypes for revealing new insights into dementia's underlying heterogeneity, rather than assuming that the cohort is homogenous. However, current studies on dementia subtyping have the following limitations: (i) focusing on AD-related dementia only and not examining heterogeneity within dementia as a whole, (ii) using only cross-sectional baseline visit information for clustering and (iii) predominantly relying on expensive imaging biomarkers as features for clustering. In this study, we seek to overcome such limitations, using a data-driven unsupervised clustering algorithm named SillyPutty, in combination with hierarchical clustering on cognitive assessment scores to estimate subtypes within a real-world clinical dementia cohort. We use a longitudinal patient data set for our clustering analysis, instead of relying only on baseline visits, allowing us to explore the ongoing temporal relationship between subtypes and disease progression over time. Results showed that subtypes with very mild or mild dementia were more heterogenous in their cognitive profiles and risk of disease progression.

The association of motor reserve and clinical progression in Parkinson's disease

OBJECTIVE

To explore the association of motor reserve (MR) and clinical progression in Parkinson's disease.

METHODS

This longitudinal study using data from the Parkinson's progression markers initiative. Patients with de novo PD who underwent dopamine transporter scans at baseline and finished at least five years clinical follow-up assessments (including motor, cognitive, and non-motor symptoms) were included. The individual MR of PD patients were estimated based on initial motor deficits and striatal dopamine depletion using a residual model. Linear mixed-effects models (LME) were performed to examine the associations of baseline MR and clinical progression.

RESULTS

A total of 303 de novo PD patients were included and the mean follow-up time was 8.95 years. Results of LME models revealed that the baseline MR was associated with motor, cognitive, and non-motor symptoms in PD patients. There was a significant interaction between MR and disease duration for longitudinal changes in motor (p < 0.001), cognitive (p = 0.028) and depression symptoms (p = 0.014). PD patients with lower MR had a more rapid progression to postural instability and cognitive impairment compared with those with higher MR (p = 0.002 and p = 0.001, respectively).

CONCLUSIONS

The baseline MR of PD patients were associated with motor and non-motor symptoms and can predicted disease prognosis, suggesting that the initial MR in PD would be associated with the individual's capacity to cope with neurodegenerative process as well as comprehensive prognosis.

Cognitive components of aging-related increase in word-finding difficulty

Word-finding difficulty (WFD) is a common cognitive complaint in aging, manifesting both in natural speech and in controlled laboratory tests. Various theories of cognitive aging have addressed WFD, and understanding its underlying mechanisms can help to clarify whether it has diagnostic value for neurodegenerative disease. Two influential "information-universal" theories attribute it to rather broad changes in cognition. The processing speed theory posits a general slowdown of all cognitive processes, while the inhibitory deficit hypothesis (IDH) predicts a specific problem in suppressing irrelevant information. One "information specific" theory of language production, the transmission deficit hypothesis (TDH), posits a breakdown in retrieval of phonological word forms from a corresponding lemma. To adjudicate between these accounts, we administered an online gamified covert naming task featuring picture-word interference (PWI), previously validated to elicit similar semantic interference and phonological facilitation effects as overt naming tasks. 125 healthy adults aged 18 to 85 completed the task, along with a battery of executive function tasks and a naturalistic speech sample to quantify WFD in connected speech. PWI effects provided strong support for the TDH but limited support for IDH, in that semantic interference increased and phonological facilitation decreased across the lifespan. However, neither of these effects on single-word retrieval associated with WFD measured in connected speech. Rather, overall reaction time for word retrieval (controlling for psychomotor slowing) was the best predictor of spontaneous WFD and executive function decline, suggesting processing speed as the key factor, and that verbal reaction time may be an important clinical measure.

Cognitive Processing Speed and Loneliness in Stroke Survivors: Insights from a Large-Scale Cohort Study

OBJECTIVE

Loneliness, when prolonged, is associated with many deleterious effects and has been shown to be highly prevalent in those with a history of stroke, yet the cognitive mechanisms underpinning this phenomenon remain unclear. Therefore, the current study aims to investigate the extent to which cognitive factors, with specific focus on processing speed, are associated with loneliness in those with a history of stroke.

METHOD

Utilizing data from the British Cohort Study, a nationally representative dataset, we conducted secondary data analysis. A total of 7,752 participants completed relevant questions related to health, social interactions, demographics, loneliness, and cognitive assessments. Among them, 47 had experienced a stroke ("stroke," n = 47), 5,545 reported other health conditions ("ill," n = 5,545), and 2,857 were deemed healthy ("healthy," n = 2,857).

RESULTS

Consistent with previous research, our findings confirmed a positive correlation between stroke history and heightened loneliness. However, inferential analysis revealed that processing speed, alongside other cognitive factors, had a minimal impact on loneliness, with correlations too small to draw definitive conclusions.

CONCLUSION

This study suggests that cognitive processing speed alone is not a robust predictor of loneliness in stroke survivors. Consequently, when developing interventions to combat loneliness in this population, it is crucial to consider a broader spectrum of factors, such as social engagement, emotional wellbeing, and interpersonal relationships. This underscores the imperative need for comprehensive assessments to better comprehend the multifaceted nature of loneliness and inform more effective intervention strategies.

Serum glial cell line-derived neurotrophic factor: a potential biomarker for white matter alteration in Parkinson's disease with mild cognitive impairment

Objective

Mild cognitive impairment (MCI) is a common non-motor manifestation of Parkinson's disease, commonly referred to as PD-MCI. However, there is a lack of comprehensive data regarding the role of glial cell line-derived neurotrophic factor (GDNF) and cerebral white matter damage in the pathogenesis of PD-MCI. The objective of this study is to investigate the association between alterations in GDNF levels and cerebral white matter damage in individuals diagnosed with PD-MCI, as well as to explore their potential involvement in cognitive progression.

Methods

Neuropsychological assessments were conducted on 105 patients with Parkinson's disease and 45 healthy volunteers to examine various cognitive domains. An enzyme-linked immunosorbent assay (ELISA) was employed to measure serum levels of GDNF. Additionally, all participants underwent 3.0T magnetic resonance imaging (MRI) to acquire diffusion tensor images (DTI), and a voxel-based analysis (VBA) approach was utilized to compare the fractional anisotropy (FA) values of white matter in the brain.

Results

There was a significant correlation between the right corpus callosum, right cingulate gyrus, and the Digit Span Backward Test (DSB-T) as well as the Trail Making Test A (TMT-A), both of which assess attention and working memory functions. The left internal capsule exhibited a significant correlation with the Trail Making Test B (TMT-B) and the Clock Drawing Test (CDT), which evaluate executive function. Additionally, the right cingulate gyrus showed a significant association with scores on the Auditory Verbal Learning Test-HuaShan (AVLT-H), assessing memory function. Abnormal fiber structures that demonstrated significant correlations with serum GDNF levels included the left internal capsule, left corticospinal tract, right corpus callosum, and right cingulate gyrus.

Conclusion

The decrease in serum GDNF levels among PD-MCI patients exhibiting impairments in attention and working memory function was significantly correlated with alterations in the corpus callosum (knee) and posterior cingulate gyrus. Furthermore, the reduction of serum GDNF levels in PD-MCI patients with impaired executive function is associated with changes in the internal capsule (forelimb) projection fibers. Additionally, the decline of serum GDNF levels in PD-MCI patients experiencing memory function impairment is related to alterations in the right cingulate gyrus.

Associations Between Cognitive Performance and Self-Efficacy for Pain Management in Older Adults With Chronic Pain

BACKGROUND

Self-efficacy for pain management is the key to successful pain management, yet little is known about the effect of cognitive performance on self-efficacy for pain management. This study aimed to examine to what extent cognitive performance is related to self-efficacy for pain management in older adults with chronic pain.

METHODS

The analyses utilized data from the baseline assessment of the MOBILIZE Boston Study. Five neuropsychological tests-the Clock in the Box Test, Letter Fluency Test, Trail-making Test, Hopkins Verbal Learning Test, and WORLD Test-were performed to measure the cognitive performance domains of 458 participants, aged 70 years and reporting chronic pain and self-efficacy for pain management. We measured self-efficacy for pain management using the Chronic Pain Self-Efficacy Scale. Statistical analyses were done using multiple linear regression analysis.

RESULTS

After adjusting for sociodemographic factors, general cognitive performance, executive function, as measured by the Clock in the Box Test, and attention, as measured by the Trail-Making Test Part A, were significantly associated with self-efficacy for pain management in older adults with chronic pain. However, after controlling for sociodemographic factors, chronic conditions, pain interference, and physical performance, the associations between cognitive performance measures and self-efficacy for pain management weakened.

CONCLUSION

Greater cognitive performance in attention and executive function might be associated with better self-efficacy for pain management. Future longitudinal research is required to investigate the long-term implications of cognitive performance changes on the progress of self-efficacy for pain management in community-dwelling older adults.

Inflammatory Cytokines and Cognition in Alzheimer's Disease and Its Prodrome

OBJECTIVE

The aim of this study was to investigate the association between blood levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and cognitive impairments among elderly individuals.

METHODS

Peripheral concentration of TNF-α and IL-6 were measured in all subjects. To assess individual cognitive function, the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery (CERAD-NP) was used, and standardized scores (z-scores) were calculated for each test. Cytokine levels were compared between the diagnostic groups, and correlations between blood inflammatory factor levels and z-scores were analyzed.

RESULTS

The 37 participants included 8 patients with Alzheimer's disease (AD), 15 subjects with mild cognitive impairment (MCI), and 14 cognitively healthy controls. TNF-α and IL-6 levels were higher in patients with AD than in healthy controls. TNF-α levels were higher in the AD group than in the MCI group. However, after adjusting for age, the associations between diagnosis and TNF-α and IL-6 were not significant. The higher the plasma IL-6 level, the lower the z-scores on the Boston Naming Test, Word List Learning, Word List Recognition, and Constructional Recall. The higher the serum TNF-α level, the lower the z-scores on the Word List Learning and Constructional Recall. Negative correlation between serum TNF-α level and the z-score on Word List Learning remained significant when age was adjusted.

CONCLUSION

The difference in the blood levels of TNF-α and IL-6 between the diagnostic groups may be associated with aging. However, elevated TNF-α levels were associated with worse immediate memory performance, even after adjusting for age.

Discriminative analysis of schizophrenia and major depressive disorder using fNIRS

BACKGROUND

Research into the shared and distinct brain dysfunctions in patients with schizophrenia (SCZ) and major depressive disorder (MDD) has been increasing. However, few studies have explored the application of functional near-infrared spectroscopy (fNIRS) in investigating brain dysfunction and enhancing diagnostic methodologies in these two conditions.

METHODS

A general linear model was used for analysis of brain activation following task-state fNIRS from 131 patients with SCZ, 132 patients with MDD and 130 healthy controls (HCs). Subsequently, seventy-seven time-frequency analysis methods were used to construct new features of fNIRS, followed by the implementation of five machine learning algorithms to develop a differential diagnosis model for the three groups. This model was evaluated by comparing it to both a diagnostic model relying on traditional fNIRS features and assessments made by two psychiatrists.

RESULTS

Brain activation analysis revealed significantly lower activation in Broca's area, the dorsolateral prefrontal cortex, and the middle temporal gyrus for both the SCZ and MDD groups compared to HCs. Additionally, the SCZ group exhibited notably lower activation in the superior temporal gyrus and the subcentral gyrus compared to the MDD group. When distinguishing among the three groups using independent validation datasets, the models utilizing new fNIRS features achieved an accuracy of 85.90 % (AUC = 0.95). In contrast, models based on traditional fNIRS features reached an accuracy of 52.56 % (AUC = 0.66). The accuracies of the two psychiatrists were 42.00 % (AUC = 0.60) and 38.00 % (AUC = 0.50), respectively.

CONCLUSION

This investigation brings to light the shared and distinct neurobiological abnormalities present in SCZ and MDD, offering potential enhancements for extant diagnostic systems.

New Evidence of Healthier Aging: Positive Cohort Effects on Verbal Fluency

Background and Objectives

Cross-sectional studies have shown improvements in cognition in later-born cohorts. However, it remains unclear whether these cohort effects extend beyond cognitive levels and are also detectable in the rate of age-related cognitive decline. Additionally, evidence is scarce on the presence and consistency of cohort effects throughout different segments of the distribution of cognitive trajectories.

Research Design and Methods

This study evaluates the existence and variability of cohort effects across the entire distribution of aging-related trajectories of verbal fluency. With this purpose, we develop sex and education-adjusted longitudinal norms of verbal fluency using data from 9 waves of the English Longitudinal Study of Aging (ELSA) by fitting quantile mixed models. The effect of age was modeled using splines to assess birth cohort effects, after grouping individuals in 5-year groups from 1920 to 1950 according to their age at study entry. To test for possible cohort effects across the 10th, 50th, and 90th quantiles, the coefficients associated with the splines were allowed to vary among cohorts.

Results

Our results suggest that, consistently across longitudinal quantiles, decline in verbal fluency across age is less pronounced for later-born individuals (p < .001), supporting the hypothesis of cohort effects. Additionally, we also found that quantiles of verbal fluency at any age are shifted upwards in later-born cohorts compared to those in earlier-born cohorts.

Discussion and Implications

These results enhance our understanding of cognitive decline in older adults by demonstrating that cohort effects on cognition are observable both cross-sectionally and longitudinally, affecting the entire range of verbal fluency trajectories.

Semantic and phonemic verbal fluency tests: Normative data for the Turkish population

Semantic and phonemic verbal fluency tests are widely used neuropsychological assessments of executive functions and language skills and are easy to administer. The aim of this study was to determine the impact of age, education, and gender on semantic and phonemic verbal fluency tests and to establish normative data for Turkish adults aged between 18 and 86 years. The results revealed significant main effects of age and education on all subscores of verbal fluency tests. Furthermore, an interaction effect between age and education was observed on semantic fluency and letter K fluency scores. While no significant differences were found among the 18-29, 30-39, and 40-49 age groups in any of the subscores, performance on the tests decreased with increasing age. Significant differences were observed among all education groups in all subscores. No main or interaction effects of gender were found on any subscore. These normative data could prove useful in clinical and research settings for the assessment of cognitive impairment.

Blood pressure, brain lesions and cognitive decline in patients with atrial fibrillation

Background

The influence of atrial fibrillation (AF) and blood pressure (BP) on brain lesions and cognitive function is unclear. We aimed to investigate the association of BP with different types of brain lesions and cognitive decline in patients with AF.

Methods

Overall, 1,213 AF patients underwent standardized brain magnetic resonance imaging at baseline and after 2 years, as well as yearly neurocognitive testing. BP was measured at baseline and categorized according to guidelines. New lesions were defined as new or enlarged brain lesions after 2 years. We defined cognitive decline using three different neurocognitive tests. Logistic and Cox regression analyses were performed to examine the associations of BP with new brain lesions and cognitive decline.

Results

The mean age was 71 ± 8.4 years, 74% were male and mean BP was 135 ± 18/79 ± 12 mmHg. New ischemic lesions and white matter lesions were found in 5.4% and 18.4%, respectively. After multivariable adjustment, BP was not associated with the presence of new brain lesions after 2 years. There was no association between BP and cognitive decline over a median follow-up of 6 years when using the Montreal Cognitive Assessment or Digit Symbol Substitution Test. However, BP categories were inversely associated with cognitive decline using the Semantic Fluency Test, with the strongest association in patients with hypertension grade 1 [Hazard Ratio (95% Confidence Interval) 0.57(0.42 to 0.77)], compared to patients with optimal BP (p for linear trend: 0.025).

Conclusions

In a large cohort of AF patients, there was no association between BP and incidence of brain lesions after 2 years. Also, there was no consistent association between BP and cognitive decline over a follow-up of 6 years.

Clinical Trial Registration

https://clinicaltrials.gov/study/NCT02105844, Identifier (NCT02105844).

Are subjective language complaints in memory clinic patients informative?

To diagnose mild cognitive impairment, it is crucial to understand whether subjective cognitive complaints reflect objective cognitive deficits. This question has mostly been investigated in the memory domain, with mixed results. Our study was one of the first to address it for language. Participants were 55-to-93-year-old memory clinic patients (n = 163). They filled in a questionnaire about subjective language and memory complaints and performed two language tasks (naming-by-definition and sentence comprehension). Greater language complaints were associated with two language measures, thus showing a moderate value in predicting language performance. Greater relative severity of language versus memory complaints was a better predictor, associated with three language performance measures. Surprisingly, greater memory complaints were associated with better naming, probably due to anosognosia in further disease progression or personality-related factors. Our findings highlight the importance of relative complaint severity across domains and, clinically, call for developing self-assessment questionnaires asking specific questions about multiple cognitive functions.

Using semantic verbal fluency to estimate the relative and absolute vocabulary size of bilinguals: An exploratory study of children and adolescents

INTRODUCTION

The full assessment of bilingual children often involves at least one language for which formal vocabulary tests are lacking and which the examiner does not speak. We examined, in a sample of children with typical development (TD), whether a semantic verbal fluency task, typically used in research as a measure of executive function, could be used in the place of a formal vocabulary test to estimate vocabulary knowledge when formal tests are not available.

METHOD

113 TD monolingual French speakers and TD bilinguals and with varying degrees of exposure to French, age 6 to 17 years, completed tests of vocabulary knowledge and semantic verbal fluency. A subset of 64 participants spoke French and English and were tested in both languages. Verbal fluency measures calculated using a traditional method which uses specific rules for superordinate categories and for animals of different sex and age and a simplified scoring method which simply counts all words produced, included the total number of words produced in each language, Total Vocabulary and Conceptual Vocabulary measures combining both languages, as well as analyses of lexical composition and word frequency within the study sample.

RESULTS

Linear regressions revealed that the number of words produced predicted vocabulary size in a language-specific way, with slightly stronger predictions made by the simplified scoring method. As expected, bilinguals produced more words and more unique words in their language of greater exposure, while different exposure groups were equivalent in measures combining both languages, including their Total vocabulary and Conceptual vocabulary. Producing unusual words (infrequently produced in the study sample) indicated higher vocabulary scores.

CONCLUSIONS

This study supports the use of the verbal fluency task as a quick and simple tool to obtain a rough estimate of vocabulary size in TD monolinguals and bilinguals. This tool shows promise as well in clinical work with other populations, subject to further verification.

The development of a cognitive screening protocol for Aboriginal and/or Torres Strait Islander peoples: the Guddi Way screen

Background Many Aboriginal and/or Torres Strait Islander peoples are exposed to risk factors for cognitive impairment. However, culturally appropriate methods for identifying potential cognitive impairment are lacking. This paper reports on the development of a screen and interview protocol designed to flag possible cognitive impairments and psychosocial disability in Aboriginal and/or Torres Strait Islander adults over the age of 16years. Methods The Guddi Way screen includes items relating to cognition and mental functions across multiple cognitive domains. The screen is straightforward, brief, and able to be administered by non-clinicians with training. Results Early results suggest the Guddi Way screen is reliable and culturally acceptable, and correctly flags cognitive dysfunction among Aboriginal and/or Torres Strait Islander adults. Conclusions The screen shows promise as a culturally appropriate and culturally developed method to identify the possibility of cognitive impairments and psychosocial disability in Aboriginal and/or Torres Strait Islander adults. A flag on the Guddi Way screen indicates the need for referral to an experienced neuropsychologist or neuropsychiatrist for further assessment and can also assist in guiding support services.

Investigating the relationship between CSAT scores and prefrontal fNIRS signals during cognitive tasks using a quantum annealing algorithm

Academic achievement is a critical measure of intellectual ability, prompting extensive research into cognitive tasks as potential predictors. Neuroimaging technologies, such as functional near-infrared spectroscopy (fNIRS), offer insights into brain hemodynamics, allowing understanding of the link between cognitive performance and academic achievement. Herein, we explored the association between cognitive tasks and academic achievement by analyzing prefrontal fNIRS signals. A novel quantum annealer (QA) feature selection algorithm was applied to fNIRS data to identify cognitive tasks correlated with CSAT scores. Twelve features (signal mean, median, variance, peak, number of peaks, sum of peaks, range, minimum, kurtosis, skewness, standard deviation, and root mean square) were extracted from fNIRS signals at two time windows (10- and 60-s) to compare results from various feature variable conditions. The feature selection results from the QA-based and XGBoost regressor algorithms were compared to validate the former's performance. In a two-step validation process using multiple linear regression models, model fitness (adjusted R2) and model prediction error (RMSE) values were calculated. The quantum annealer demonstrated comparable performance to classical machine learning models, and specific cognitive tasks, including verbal fluency, recognition, and the Corsi block tapping task, were correlated with academic achievement. Group analyses revealed stronger associations between Tower of London and N-back tasks with higher CSAT scores. Quantum annealing algorithms have significant potential in feature selection using fNIRS data, and represents a novel research approach. Future studies should explore predictors of academic achievement and cognitive ability.

Language and executive functions in patients with transcortical motor aphasia and Broca's aphasia

This study investigated language and executive functions (EF) in people with transcortical motor aphasia (TMA) and Broca's aphasia (BA). Participants included 19 patients with TMA, 19 patients with BA, and 25 healthy controls. Verbal Fluency tests, Stroop tests and Trail-Making tests were administered to all participants, and the Boston Diagnostic Aphasia Examination (BDAE) was administered to participants with aphasia. Results showed that (1) both groups of patients with aphasia had poorer performance on Verbal Fluency tests, Stroop tests and Trail-Making tests than healthy controls; (2) participants with BA had superior performance on Stroop tests and Trail-Making tests, but not on Verbal Fluency tests, than participants with TMA, and (2) the performance on Verbal Fluency tests, Stroop tests and Trail-Making was significantly correlated with the performance on BDAE for participants with TMA, but not for participants with BA. These results suggest that EF deficits are present in both patients with TMA and those with BA. They also show that the relationship between EF deficits and language impairments in people with aphasia might depend on the type of aphasia, aspects of language, and the components of EF measured.

The Contributions of the Cerebellar Peduncles and the Frontal Aslant Tract in Mediating Speech Fluency

Fluent speech production is a complex task that spans multiple processes, from conceptual framing and lexical access, through phonological encoding, to articulatory control. For the most part, imaging studies portraying the neural correlates of speech fluency tend to examine clinical populations sustaining speech impairments and focus on either lexical access or articulatory control, but not both. Here, we evaluated the contribution of the cerebellar peduncles to speech fluency by measuring the different components of the process in a sample of 45 neurotypical adults. Participants underwent an unstructured interview to assess their natural speaking rate and articulation rate, and completed timed semantic and phonemic fluency tasks to assess their verbal fluency. Diffusion magnetic resonance imaging with probabilistic tractography was used to segment the bilateral cerebellar peduncles (CPs) and frontal aslant tract (FAT), previously associated with speech production in clinical populations. Our results demonstrate distinct patterns of white matter associations with different fluency components. Specifically, verbal fluency is associated with the right superior CP, whereas speaking rate is associated with the right middle CP and bilateral FAT. No association is found with articulation rate in these pathways, in contrast to previous findings in persons who stutter. Our findings support the contribution of the cerebellum to aspects of speech production that go beyond articulatory control, such as lexical access, pragmatic or syntactic generation. Further, we demonstrate that distinct cerebellar pathways dissociate different components of speech fluency in neurotypical speakers.

Cognitive functioning and sustained internet use amid the COVID-19 pandemic: longitudinal evidence from older adults in Switzerland

This study aimed to investigate the relationship between pre-pandemic objective and subjective cognitive functioning and sustained Internet use during the pandemic among older adults in Switzerland. Data from 1299 respondents of the Survey of Health, Ageing and Retirement in Europe (SHARE) in 2019/2020 and a supplementary technology use questionnaire during the pandemic in 2021 were used. Cognitive functioning was assessed in 2019/2020 through objective measures (delayed and immediate memory, verbal fluency) and self-rated memory. Sustained Internet use was defined as having used the Internet at least once in the past seven days in 2019/2020 and reporting daily or weekly use in 2021. We found that 73.1% of respondents consistently used Internet between 2019/2020 and 2021. Using multivariable probit regression models controlling for sociodemographic and health variables, we found that higher global cognition z-scores, especially in immediate and delayed memory, were associated with a higher likelihood of sustained Internet use. Additionally, respondents with good, very good, or excellent self-rated memory were more likely to sustain their Internet use. These findings highlight the potential critical role of cognitive health in shaping older adults' digital engagement, suggesting that cognitive assessments and training should be further considered in digital literacy initiatives for this population.

Social cognition in Parkinson's disease and functional movement disorders

INTRODUCTION

Functional movement disorders (FMD) can overlap with Parkinson's disease (PD), and distinguishing between the two clinical conditions can be complex. Framing social cognition (theory of mind) (TOM) disorder, attention deficit, and psychodynamic features of FMD and PD may improve diagnosis.

METHODS

Subjects with FMD and PD and healthy controls (HC) were administered tasks assessing TOM abilities and attention. The psychodynamic hypothesis of conversion disorder was explored by a questionnaire assessing dissociative symptoms. A comprehensive battery of neuropsychological tasks was also administered to FMD and PD.

RESULTS

Although both FMD and PD scored lower than HC on all TOM tests, significant correlations between TOM and neuropsychological tasks were found only in PD but not in FMD. Only PD showed a reduction in attentional control. Dissociative symptoms occurred only in FMD.

DISCUSSION

Cognitive-affective disturbances are real in FMD, whereas they are largely dependent on cognitive impairment in PD. Attentional control is preserved in FMD compared to PD, consistent with the hypothesis that overload of voluntary attentional orientation may be at the basis of the onset of functional motor symptoms. On a psychodynamic level, the confirmation of dissociative symptoms in FMD supports the conversion disorder hypothesis.

CONCLUSION

FMD and PD can be distinguished on an affective and cognitive level. At the same time, however, the objective difficulty often encountered in distinguishing between the two pathologies draws attention to how blurred the boundary between 'organic' and 'functional' can be.

A scoping review of incidence and assessment tools for post-intensive care syndrome following cardiac surgery

BACKGROUND

Post-intensive care syndrome is a new or worsening persistent deterioration in cognitive, mental, and/or physical health following a prolonged admission to an intensive care unit. Post-intensive care syndrome remains underexplored following cardiac surgery, with a lack of understanding of the incidence and tools used to measure the symptoms. A scoping review was conducted to determine the incidence and to identify the tools commonly used to measure symptoms of post-intensive care syndrome following cardiac surgery.

METHODS

The electronic databases Medline (Ovid), EMBASE (Ovid), PsycINFO (Ovid), Scopus, and CINAHL (EBSCOhost) and Google Scholar were searched with keywords and controlled vocabulary to describe both cardiac surgery and post-intensive care syndrome (cardiac surgical procedures, heart surgery, and post-intensive care symptoms) and symptoms (delirium, depression, mobility and quality of life). Included were articles written in English and published after 2005 that described cognitive, mental, and physical symptoms of post-intensive care syndrome following cardiac surgery. 3,131 articles were found, with 565 duplicates, leaving 2,566 articles to be screened. Of these, seven unique studies were included.

RESULTS

Five studies explored cognitive health, three mental health, one cognitive and mental health, and none physical health. No identified studies reported the overall incidence of post-intensive care syndrome following cardiac surgery. The incidence of cognitive health issues ranged from 21% to 38%, and mental health issues ranged from 16% to 99%. In total, 17 different tools were identified - 14 for cognitive health and three for mental health. No identified studies used the same tools to measure symptoms. No single tool was found to measure all three domains.

CONCLUSION

This scoping review identified a literature gap specific to the incidence and inconsistency of assessment tools for post-intensive care syndrome in cardiac surgery patients.

CLINICAL IMPLICATIONS

This work impacts clinical practice for the bedside nurse by raising awareness of an emerging health issue.

Linked patterns of symptoms and cognitive covariation with functional brain controllability in major depressive disorder

BACKGROUND

Controllability analysis is an approach developed for evaluating the ability of a brain region to modulate function in other regions, which has been found to be altered in major depressive disorder (MDD). Both depressive symptoms and cognitive impairments are prominent features of MDD, but the case-control differences of controllability between MDD and controls can not fully interpret the contribution of both clinical symptoms and cognition to brain controllability and linked patterns among them in MDD.

METHODS

Sparse canonical correlation analysis was used to investigate the associations between resting-state functional brain controllability at the network level and clinical symptoms and cognition in 99 first-episode medication-naïve patients with MDD.

FINDINGS

Average controllability was significantly correlated with clinical features. The average controllability of the dorsal attention network (DAN) and visual network had the highest correlations with clinical variables. Among clinical variables, depressed mood, suicidal ideation and behaviour, impaired work and activities, and gastrointestinal symptoms were significantly negatively associated with average controllability, and reduced cognitive flexibility was associated with reduced average controllability.

INTERPRETATION

These findings highlight the importance of brain regions in modulating activity across brain networks in MDD, given their associations with symptoms and cognitive impairments observed in our study. Disrupted control of brain reconfiguration of DAN and visual network during their state transitions may represent a core brain mechanism for the behavioural impairments observed in MDD.

FUNDING

National Natural Science Foundation of China (82001795 and 82027808), National Key R&D Program (2022YFC2009900), and Sichuan Science and Technology Program (2024NSFSC0653).

Errorful learning improves recognition memory for new vocabulary for people living with memory and dysexecutive impairment following brain injury

A widely accepted view is that errorless learning is essential for supporting new learning in people with anterograde amnesia, but findings are mixed for those with a broader range of memory impairments. People at a chronic stage of recovery from brain injury (BI) with impaired memory and executive function (N = 26) were compared with adults in a comparison group without any known risks to brain function (N = 25). Learning techniques were compared using a "Generate-and-correct" and "Read-only" condition when learning novel word pairs. At test, both groups scored above chance and showed benefits of Generate-and-correct (errorful learning). Poor learners in the BI group were classified from "flat" learning slopes extracted from an independent word-pair learning task. Critically, poor learners showed no benefit, but also no decrement to learning, using the Generate-and-correct method. No group was harmed by errorful learning; all, except the poorest learners, benefitted from errorful learning. This study indicates, that in some rehabilitation settings, encouraging clients to guess the meaning of unfamiliar material (e.g., from cards, magazines, newspapers) and then correct their errors, could have benefits for recognition memory. Determining when and how errorful learning benefits learning is a key aim for future research.

Sex Differences in the Association Between Cumulative Use of Cannabis and Cognitive Function in Middle Age: The Coronary Artery Risk Development in Young Adults Study

Background: Cannabis use may impair cognitive function (CF) differently in men and women, due to sex-specific differences in neurobiological mechanisms and environmental risk factors. Objective: Assess sex differences in the association between cumulative exposure to cannabis and cognitive performance in middle age. Methods: We studied participants from the Coronary Artery Risk Development in Young Adults (CARDIA) Study, including Black and White men and women 18-30 years old at baseline followed over 30 years. Our cross-sectional analysis of CF scores at year 30 was stratified by sex. We computed categories of cumulative exposure in "cannabis-years" (1 cannabis-year=365 days of use) from self-reported use every 2 to 5 years over 30 years. At years 25 and 30, we assessed CF with the Rey Auditory Verbal Learning Test (verbal memory), the Digit Symbol Substitution Test (processing speed), and the Stroop Interference Test (executive function). At year 30, additional measures included Category and Letter Fluency Test (verbal ability) and the Montreal Cognitive Assessment (global cognition). We computed standardized scores for each cognitive test and applied multivariable adjusted linear regression models for self-reported cumulative cannabis use, excluding participants who used cannabis within 24 h. In a secondary analysis, we examined the association between changes in current cannabis use and changes in CF between years 25 and 30. Results: By year 30, 1,352 men and 1,793 women had measures of CF; 87% (N=1,171) men and 84% (N=1,502) women reported ever cannabis use. Men had a mean cumulative use of 2.57 cannabis-years and women 1.29 cannabis-years. Self-reported cumulative cannabis use was associated with worse verbal memory in men (e.g., -0.49 standardized units [SU] for ≥5 cannabis-years of exposure; 95% CI=-0.76 to -0.23), but not in women (SU=0.02; 95% CI=-0.26 to 0.29). Other measures of CF were not associated with cannabis. Changes in current cannabis use between years 25 and 30 were not associated with CF in men or women. Conclusions: Self-reported cumulative cannabis exposure was associated with worse verbal memory in men but not in women. Researchers should consider stratified analyses by sex when testing the association between cannabis and cognition.

Association of Depression and Cognitive Performance in US Older Adults: A Secondary Analysis of Cross-Sectional Data Using NHANES 2013-2014

INTRODUCTION

Depression has been associated with cognitive performance, but whether sociodemographic and clinical characteristics might influence this association is not well elaborated. This study aimed to further explore this relationship in older adults.

METHODS

This cross-sectional study is based on data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014. A total of 1,433 individuals with complete information on depressive symptoms and cognitive function variables were included in this study. Patient Health Questionnaire 9 (PHQ-9) score ≥10 as the cutoff to identify cases of depression in our study. We defined poor cognitive performance as a composite cognitive score <47. Logistic regression models were used to examine the association of depression with cognitive performance (model 1). We progressively adjusted the covariates as confounders (model 2: model 1 + age, and gender; model 3: model 2 + race, education level, family income, drinking, and smoking; model 4: model 3 + overweight, arthritis, hyperlipidemia, diabetes, hypertension, heart failure, coronary heart disease, heart attack, stroke, and cancer). We then conducted subgroup, interaction, and restricted cubic spline (RCS) analyses to examine this association.

RESULTS

The prevalence of poor cognitive performance was 36.6% (53/145) in the depression group and 14.1% (182/1,288) in the non-depression group. In the fully adjusted model, depression was significantly associated with poor cognitive performance (adjusted odds ratio: 2.25; 95% confidence interval: 1.31-3.81). The results were robust to sensitivity analyses. Gender and education level may modify the association between depression and poor cognitive performance. RCS analysis revealed that the PHQ-9 score was related to poor cognitive performance in a nonlinear manner (p for nonlinearity <0.001), and exhibited a J-shaped curve.

CONCLUSION

Depression is associated with poor cognitive performance in US older adults. Early recognition and treatment of depression may be potential intervention strategies to protect cognitive health.

Normative Data for the Famous People Fluency Test in the Adult French-Quebec Population and Validation Study in Mild Cognitive Impairment and Alzheimer's Disease

OBJECTIVE

The production of words in verbal fluency tests relies heavily on executive functions and linguistic abilities. New tests such as the famous people fluency test can also be useful in clinical practice and research. This test, in which participants are asked to name so many famous people, has the potential to distinguish healthy individuals from participants with neurological disorders such as mild cognitive impairment or Alzheimer's disease.

METHOD

The aim of this study was to determine the psychometric validity of the test (Study 1) and to provide normative data in the adult population of French Quebec for the famous people fluency test (Study 2).

RESULTS

The results of the normative study, derived from a sample of 378 healthy individuals between the ages of 50 and 92, showed that age and educational level significantly influence performance on the test. Therefore, percentile ranks were calculated for performance on the famous people fluency test, stratified for these two variables. The results of Study 2 showed that the test differentiated the performance of healthy participants from the performance of participants with mild cognitive impairment or Alzheimer's disease. The results also showed that the famous people fluency test has adequate convergent validity, established with a semantic fluency test, and that the results showed good stability over time (test-retest validity).

CONCLUSION

Norms and psychometric data for the famous people fluency test will improve the ability of clinicians and researchers to better recognize executive and language impairments associated with pathological conditions.

Quantitative transport mapping of multi-delay arterial spin labeling MRI detects early blood perfusion alterations in Alzheimer's disease

BACKGROUND

Quantitative transport mapping (QTM) of blood velocity, based on the transport equation has been demonstrated higher accuracy and sensitivity of perfusion quantification than the traditional Kety's method-based cerebral blood flow (CBF). This study aimed to investigate the associations between QTM velocity and cognitive function in Alzheimer's disease (AD) using multiple post-labeling delay arterial spin labeling (ASL) MRI.

METHODS

A total of 128 subjects (21 normal controls (NC), 80 patients with mild cognitive impairment (MCI), and 27 AD) were recruited prospectively. All participants underwent MRI examination and neuropsychological evaluation. QTM velocity and traditional CBF maps were computed from multiple delay ASL. Regional quantitative perfusion measurements were performed and compared to study group differences. We tested the hypothesis that cognition declines with reduced cerebral blood perfusion with consideration of age and gender effects.

RESULTS

In cortical gray matter (GM) and the hippocampus, QTM velocity and CBF showed decreased values in the AD group compared to NC and MCI groups; QTM velocity, but not CBF, showed a significant difference between MCI and NC groups. QTM velocity and CBF showed values decreasing with age; QTM velocity, but not CBF, showed a significant gender difference between male and female. QTM velocity and CBF in the hippocampus were positively correlated with cognition, including global cognition, memory, executive function, and language function.

CONCLUSION

This study demonstrated an increased sensitivity of QTM velocity as compared with the traditional Kety's method-based CBF. Specifically, we observed only in QTM velocity, reduced perfusion velocity in GM and the hippocampus in MCI compared with NC. Both QTM velocity and CBF demonstrated a reduction in AD vs. controls. Decreased QTM velocity and CBF in the hippocampus were correlated with poor cognitive measures. These findings suggest QTM velocity as potential biomarker for early AD blood perfusion alterations and it could provide an avenue for early intervention of AD.

The grasp reflex in patients with idiopathic normal pressure hydrocephalus

OBJECTIVE

To investigate the prevalence and intensity of grasp reflexes and to examine changes in these reflexes after shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH).

METHODS

We enrolled 147 patients with probable iNPH. A standard procedure was used to determine the presence of grasp reflexes, and the intensity of these reflexes was assessed using a four-category classification. Clinical rating scales and their correlation with grasp reflexes were also evaluated. Grasp reflexes were reassessed in 72 patients 1 year after surgery.

RESULTS

We found that approximately 50.3% of patients with iNPH exhibited a positive grasp reflex. Among these patients, 69% exhibited bilateral positivity, while the remaining patients showed unilateral positivity. Furthermore, the intensity of the grasp reflex was significantly correlated with the severity of gait and with cognitive, urinary, motor, and behavioural symptoms. Surgical interventions led to a reduction (41.7%) or maintenance (30.6%) of the reflex intensity in 72.3% of iNPH patients. The changes in reflex intensity showed significant positive correlations with changes in the number of steps of the Timed Up and Go test and Trail Making Test-A scores but not with changes in total scores on the iNPH Grading Scale.

CONCLUSION

This retrospective study identified grasp reflexes as a highly prevalent phenomenon in patients with iNPH. These reflexes can assist in evaluating the severity of various symptoms, including cognitive, gait, urinary, motor and emotional symptoms.

Verbal fluency in Lebanese children: Preliminary normative data, sociodemographic determinants, and patterns of clustering and switching

This study assessed the quantitative and qualitative performance of Lebanese-speaking children on verbal fluency (VF) tasks and investigated the effects of sociodemographic characteristics. This study included 219 Lebanese children aged between 5 and 12 years and 11 months, whose native language is Lebanese-Arabic. Semantic and letter VF tasks were assessed using a range of categories and letters. Switching and clustering strategies were analyzed for 177 Lebanese children. The number of words produced presented a significant increase with age (p < .004) in semantic (SVF), while in letter (LVF), the differences were significant between extreme age groups. Females generated more words in the clothes (p = .003) and household items (p = .002) categories. The total number of switches and clusters showed a significantly increasing pattern with age (p < .05). The number of switches was higher for participants with high maternal (p < .001) and paternal (p < .013) educational levels. Regression analyses showed that the total number of switches and clusters, and the mean cluster size had a significant effect on SVF performance (p < .001). The current study generated preliminary norms for VF tasks for Lebanese-speaking children. The results of the current study have an important contribution to neuropsychology research and clinical practice.

Normative Data Study of Verbal Fluency and Naming Tests in Elderly People in Costa Rica

OBJECTIVE

To generate normative data for the Verbal Fluency Test (VFT) and the Boston Naming Test (BNT) in the Costa Rican population.

METHOD

The sample consisted of 563 healthy older people (aged 59-90 years). Polynomial multiple regression analyses were run to evaluate the effects of the age, sex, and education variables on VFT and BNT scores.

RESULTS

The results showed a significant linear effect of education on the four-letter VF scores and an effect of sex on the letter P score, with females performing better than males. The explained variance ranged from 20.9% to 28.3%. A linear effect of age and education was also found for the four semantic VF scores, with scores decreasing with increasing age and lower education. The sex variable was significant for all semantic categories, with females performing better than males except in the animal category. The explained variance ranged from 21.7% to 30.9%. In the BNT, a linear effect of education was found, so that the more education, the better the score. In addition, a sex effect was also found, with males having higher scores than females. The predictors of the model explained 9.6% of the variance.

CONCLUSIONS

This is the first study that generates normative data for the VF and BNT in the Costa Rican population over 59 years of age based on demographic variables. The use of these normative data will help clinicians in Costa Rica to better understand language functioning in the elderly, allowing for better classification and diagnosis in the future.

Fronto-thalamic networks and the left ventral thalamic nuclei play a key role in aphasia after thalamic stroke

Thalamic aphasia results from focal thalamic lesions that cause dysfunction of remote but functionally connected cortical areas due to language network perturbation. However, specific local and network-level neural substrates of thalamic aphasia remain incompletely understood. Using lesion symptom mapping, we demonstrate that lesions in the left ventrolateral and ventral anterior thalamic nucleus are most strongly associated with aphasia in general and with impaired semantic and phonemic fluency and complex comprehension in particular. Lesion network mapping (using a normative connectome based on fMRI data from 1000 healthy individuals) reveals a Thalamic aphasia network encompassing widespread left-hemispheric cerebral connections, with Broca's area showing the strongest associations, followed by the superior and middle frontal gyri, precentral and paracingulate gyri, and globus pallidus. Our results imply the critical involvement of the left ventrolateral and left ventral anterior thalamic nuclei in engaging left frontal cortical areas, especially Broca's area, during language processing.