Search Results (13)

Background/Objectives: We examined the effects of cardiovascular exercise on verbal fluency using a between-groups design. Methods: Within our experimental (i.e., exercise) group, participants performed phonemic and semantic verbal fluency tasks (VFTs) before, during, and after a vigorous 30 min bout of cycling. Participants within our control group also completed these VFTs before, during, and after a non-physical activity. We compared the VFT performance of the experimental (exercise) and control (no-exercise) groups of participants in terms of the characteristics of the words that they produced within the VFTs. In addition, we examined these aspects of VFT performance for each participant group across time within the experiment session. Conclusions: From these comparisons, we see that exercise influenced VFT performance. Most notably, participants engaged in exercise changed their VFT performance over time, while control group participants did not. Exercising participants produced more words over the course of their exercise session that contained fewer letters over time and were lower in frequency during and after exercise as compared to before exercise. Additionally, topic switches in the VFTs increased after exercise as compared to before exercise. Participants in the control group did not change their VFT performance over time according to any of these measures. These findings indicate that exercise impacted participants’ lexical access and that these VFT performance changes were not due to practice effects. Full article

Background: In this narrative review, we have surveyed results obtained from a research program dealing with the role of semantic memory disorders as a predictor of progression from mild cognitive impairment (MCI) to Alzheimer’s disease (AD). Objectives: In this research program, we have taken into account many different putative markers, provided of a different complexity in the study of the semantic network. These markers ranged from the number of words produced on a semantic fluency task to the following: (a) the discrepancy between scores obtained on semantic vs. phonemic word fluency tests; (b) the presence, at the single-word level, of features (such as a loss of low typical words on a category verbal fluency task) typical of a degraded semantic system; or (c) the presence of more complex phenomena (such as the semantic distance between consecutively produced word pairs) concerning the organization of the semantic network. In the present review, all these studies have been presented, providing separate subsections for (a) methods, (b) results, and (c) a short discussion. Some tentative general conclusions have been drawn at the end of the review. We found that at baseline all these markers are impaired in MCI patients who will later convert to AD, but also that they do not necessarily show a linear worsening during the progression to AD and allow one to make different predictions about the time of development of AD. Our conclusions were that, rather than searching for the best marker of conversion, we should use a range of different markers allowing us to obtain the information most appropriate to the goal of our investigation. Full article

Background: Among the cognitive markers, the deterioration of semantic and phonemic verbal fluency seems to be an early indicator of Alzheimer’s disease (AD). The aims of this study are (1) to evaluate both types of verbal fluency in the early stages of AD in order to know which of them deteriorates earlier and (2) to investigate if verbal fluency tasks can help to differentiate between patients with Mild Cognitive Impairment (MCI) who will progress to AD two years later (progress) and those who will not (non-progress). Method: A verbal fluency task was administered to 25 patients with MCI and their respective control subjects. All patients underwent a neuropsychological evaluation twice in order for us to follow up on their global cognitive status. The second time, eight of them converted to AD. Results: On the one hand, phonemic verbal fluency deteriorates earlier than semantic verbal fluency in MCI patients; on the other hand, although we found statistically significant differences between patients with MCI and AD in both types of fluency tasks, none were found when comparing the performance of progress and non-progress. Conclusions: These results point to a greater impairment in phonemic verbal fluency in MCI patients and its potential capacity to predict conversion to AD. Full article

Background: Parents report associations between children’s sleep disturbances and behaviors. Children with neurodevelopmental conditions (e.g., Williams Syndrome and autism) are consistently reported to experience increased sleeping problems. Sleep in children with vision impairment and children with a dual diagnosis of vision impairment and autism remains understudied. Methods: Our exploratory study compared sleep profiles in 52 children (aged 4–12 years) and their parents (n = 37), across four groups: children with vision impairment (VI; n = 9), autism (n = 10), comorbid vision impairment + autism (n = 6), and typically developing children (n = 27). Childhood sleep was measured using the parental report Childhood Sleep Habits Questionnaire and sleep diaries. Children’s cognitive functioning was measured using digit span, semantic, and phonemic verbal fluency measures. Parental sleep was measured via the Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale. Results: Clinically disordered sleep was reported in all child groups (p ≤ 0.001), particularly children with VI + autism. Age, not sleep quality/quantity, predicted cognitive task performance in TD and autistic groups, but not in VI and VI + autism groups. The child’s diagnosis affected parental sleep, particularly in children with a dual diagnosis of VI + autism. Conclusions: All participants experienced problematic sleep to varying degrees. Those most affected were children and parents in the VI + autism group, suggesting that autism may be the main driver of sleep problems in our sample. Full article

Background and Objectives: The present study explored the utilization of verbal fluency (VF) cognitive strategies, including clustering, switching, intrusions, and perseverations, within both semantic (SVF) and phonemic (PVF) conditions, across a continuum of neurocognitive decline, spanning from normal cognitive ageing (NC) to mild cognitive impairment (MCI) and its subtypes, amnestic (aMCI) and non-amnestic (naMCI), as well as AD. Materials and Methods: The study sample was derived from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD) cohort. The sample included 1607 NC individuals, 146 with aMCI (46 single-domain and 100 multi-domain), 92 with naMCI (41 single-domain and 51 multi-domain), and 79 with AD. Statistical analyses, adjusting for sex, age, and education, employed multivariate general linear models to probe differences among these groups. Results: Results showed that AD patients exhibited poorer performance in switching in both VF tasks and SVF clustering compared to NC. Similarly, the aMCI group performed worse than the NC in switching and clustering in both tasks, with aMCI performing similarly to AD, except for SVF switching. In contrast, the naMCI subgroup performed similarly to those with NC across most strategies, surpassing AD patients. Notably, the aMCI subgroup’s poor performance in SVF switching was mainly due to the subpar performance of the multi-domain aMCI subgroup. This subgroup was outperformed in switching in both VF tasks by the single-domain naMCI, who also performed better than the multi-domain naMCI in SVF switching. No significant differences emerged in terms of perseverations and intrusions. Conclusions: Overall, these findings suggest a continuum of declining switching ability in the SVF task, with NC surpassing both aMCI and AD, and aMCI outperforming those with AD. The challenges in SVF switching suggest executive function impairment associated with multi-domain MCI, particularly driven by the multi-domain aMCI. Full article

Recent evidence has shown a relationship between physical exercise (PE) and cognitive functioning. However, it is unknown if unimodal and multimodal modalities of PE affect cognitive abilities in different ways. To fill this gap, we analyzed the effects of unimodal PE (running) and multimodal PE (Tai Chi) on specific cognitive abilities. A sample of 33 participants (mean age = 52.6 ± 7.2) divided into eleven runners, eleven Tai Chi practitioners, and eleven age-matched sedentary individuals were subjected to a neuropsychological tests battery to assess shifting and problem solving abilities (Rule Shift Cards, BADS-RS, and Key Search tasks), verbal fluency (semantic and phonemic verbal fluency tasks), verbal memory (Rey’s 15 words test), visuo-spatial working memory (Corsi test), and global cognitive functioning (clock-drawing test). The results showed significantly higher BADS-RS scores in runners and Tai Chi practitioners in comparison to the sedentary participants, thus evidencing improved shifting abilities for active individuals. Interestingly, post hoc analysis showed significantly higher span scores of Corsi test only in Tai Chi practitioners as compared to sedentary participants, suggesting how multimodal PE facilitates the visuo-spatial working memory processes. Although preliminary, our descriptive study indicates that the type of PE could modulate specific cognitive domains, even if the practice of motor activity favors a global cognitive improvement. Full article

Individuals with attention deficit hyperactivity disorder (ADHD) struggle with impaired verbal fluency as an executive function. The left and right dorsolateral prefrontal cortex (dlPFC) and the right inferior frontal gurus (IFG), which show reduced functionality in individuals with ADHD, are involved in verbal fluency. In this study, a total of thirty-seven children with ADHD participated in two separate experiments. Each experiment included three different stimulation conditions: anodal left dlPFC/cathodal right vmPFC stimulation, the reversed montage, and a sham stimulation in Experiment 1, and anodal right dlPFC, anodal right IFG with extracranial return electrode, and a sham stimulation in Experiment 2. During each session, participants performed semantic and phonemic verbal fluency tasks while receiving tDCS. The results revealed a significant main effect of stimulation condition on phonemic verbal fluency during anodal left dlPFC stimulation in Experiment 1, and on semantic verbal fluency during both real stimulation conditions in Experiment 2. In conclusion, this study suggests that anodal left dlPFC stimulation improves phonemic verbal fluency, while anodal right dlPFC and right IFG stimulation enhance semantic verbal fluency. This domain-specific improvement can be attributed to the distinct cognitive demands of phonemic and semantic verbal fluency tasks. Phonemic verbal fluency heavily relies on working memory processes, whereas semantic verbal fluency requires effective inhibitory control and cognitive flexibility. Full article

Cochlear implantation gives children with prelingual severe hearing loss and deafness the opportunity to develop their hearing abilities, speech, language, cognitive abilities and academic skills with adequate rehabilitation. The aim of the research was to analyze verbal, figural and arithmetic fluency and their interrelationship in children with a cochlear implant (CI) and children with normal hearing (NH). A total of 46 children with CI and 110 children with NH, aged 9 to 16, participated in the research. Verbal fluency was assessed using phonemic and semantic fluency, and non-verbal fluency using figural fluency. Arithmetic fluency was assessed using simple arithmetic tasks within the number range up to 100. The results showed that children with CI achieved poorer results in phonemic fluency (z = −4.92; p < 0.001), semantic fluency (z = −3.89; p < 0.001), figural fluency (z = −3.07; p = 0.002), and arithmetic fluency (z = −4.27; p < 0.001). In both groups, a positive correlation was obtained between the measured modalities and types of fluency. In the group of children with CI, a sex difference was obtained on the phonemic fluency test, in favor of girls. The age of children with CI was correlated with arithmetic fluency. Verbal, figural and arithmetic fluency of children with CI speak in favor of the importance of early auditory and language experiences. Full article

Background and Objectives: The aim of the present study was to investigate the prognostic value of the qualitative components of verbal fluency (clustering, switching, intrusions, and perseverations) on the development of mild cognitive impairment (MCI) and dementia. Materials and Methods: Participants were drawn from the multidisciplinary, population-based, prospective HELIAD (Hellenic Longitudinal Investigation of Aging and Diet) cohort. Two participant sets were separately analysed: those with normal cognition and MCI at baseline. Verbal fluency was assessed via one category and one letter fluency task. Separate Cox proportional hazards regressions adjusted for important sociodemographic parameters were performed for each qualitative semantic and phonemic verbal fluency component. Results: There were 955 cognitively normal (CN), older (72.9 years ±4.9), predominantly female (~60%) individuals with available follow-up assessments after a mean of 3.09 years (±0.83). Among them, 34 developed dementia at follow-up (29 of whom progressed to Alzheimer’s dementia (AD)), 160 developed MCI, and 761 remained CN. Each additional perseveration on the semantic condition increased the risk of developing all-cause dementia and AD by 52% and 55%, respectively. Of note, participants with two or more perseverations on the semantic task presented a much more prominent risk for incident dementia compared to those with one or no perseverations. Among the remaining qualitative indices, none were associated with the hazard of developing all-cause dementia, AD, and MCI at follow-up. Conclusions: Perseverations on the semantic fluency condition were related to an increased risk of incident all-cause dementia or AD in older, CN individuals. Full article

Mild cognitive impairment (MCI) is an early stage of cognitive decline or memory loss, commonly found among the elderly. A phonemic verbal fluency (PVF) task is a standard cognitive test that participants are asked to produce words starting with given letters, such as “F” in English and “ก” /k/ in Thai. With state-of-the-art machine learning techniques, features extracted from the PVF data have been widely used to detect MCI. The PVF features, including acoustic features, semantic features, and word grouping, have been studied in many languages but not Thai. However, applying the same PVF feature extraction methods used in English to Thai yields unpleasant results due to different language characteristics. This study performs analytical feature extraction on Thai PVF data to classify MCI patients. In particular, we propose novel approaches to extract features based on phonemic clustering (ability to cluster words by phonemes) and switching (ability to shift between clusters) for the Thai PVF data. The comparison results of the three classifiers revealed that the support vector machine performed the best with an area under the receiver operating characteristic curve (AUC) of 0.733 (N = 100). Furthermore, our implemented guidelines extracted efficient features, which support the machine learning models regarding MCI detection on Thai PVF data. Full article

Verbal Fluency Tests (VFT) are one of the most common neuropsychological tasks used in bipolar disorder (BD) and schizophrenia (SZ) research. Recently, a new VFT analysis method based on graph theory was developed. Interpreting spoken words as nodes and every temporal connection between consecutive words as edges, researchers created graph structures, allowing the extraction of more data from participants’ speech, called Speech Graph Attributes (SGA). The aim of our study was to compare speech graphs, derived from Phonemic and Semantic VFT, between SZ, BD, and healthy controls (HC). Twenty-nine SZ patients, twenty-nine BD patients, and twenty-nine HC performed Semantic and Phonemic VFT. Standard measures (SM) and 13 SGA were analyzed. SZ patients’ Semantic VFT graphs showed lower total word count and correct responses. Their graphs presented less nodes and edges, higher density, smaller diameter, average shortest path (ASP), and largest strongly connected component than the HC group. SM did not differentiate BD and HC groups, and patients’ Semantic VFT graphs presented smaller diameter and ASP than HC. None of the parameters differentiated BD and SZ patients. Our results encourage the use of speech graph analysis, as it reveals verbal fluency alterations that remained unnoticed in the routine comparisons of groups with the use SM. Full article

Background: Parkinson’s disease [PD] is associated with reduced motor and cognitive initiation, and decreased goal-directed behavior including language generation. The current study investigated a novel goal intervention for language generation impairments in PD patients. Methods: Twenty-one PD patients and 22 healthy controls, matched for gender, age, and education, completed a cognitive baseline and language generation tasks (complex scene descriptions and phonemic/semantic word fluency) with standard and adapted instructions, which implements a target ‘goal’. In addition, participants completed self-report questionnaires for apathy and mood. Results: PD patients performed more poorly on two of three language generation tasks. The goal intervention was effective in increasing both the PD patient and healthy control groups’ language generation. However, there was no differential benefit of increased goal specificity and difficulty for PD patients. As a group, PD patients reported higher levels of apathy and depression than healthy controls. Specifically, PD patients with executive apathy were more likely to have language generation impairments than PD patients without executive apathy and controls. Apathy subscales and goal benefit were unrelated. Conclusions: The goal intervention was effective for PD patients and older adults, suggesting that enhanced goal specificity and difficulty may benefit individuals with PD or those aging naturally. Full article

Background: Coffee is one of the most consumed beverages worldwide and the effect on cognition appears to be task specific and vary by age. Method: In cohort of 14,563 public service workers (35–74 years old) we assessed coffee consumption habits and examined cognitive function using standardized neuropsychological test battery. By linear regression and generalize linear regression with logarithmic link and gamma distribution we investigated the relation of coffee consumption (never/almost never, ≤1 cup/day, 2–3 cups/day, ≥3 cups/day) in the last 12 months to performance on specific domains of cognition for adults and elderly separately. Results: Among elderly, after adjustments, coffee consumption was associated only with an increase in the mean words remembered on learning, recall, and word recognition tests when comparing the 2–3 cups/day to never/almost never category (arithmetic mean ratio (AMR): 1.03; 95% Confidence Interval (CI): 1.00 to 1.07), and to an increase in the mean words pronounced in semantic verbal fluency test when comparing the ≥3 cups/day to never/almost never category (difference of the mean: 1.23; 95% CI: 0.16 to 2.29). However, coffee consumption was not associated with any cognitive function tests in adults and also was not associated with the phonemic verbal fluency test and trail-making test B in elderly. Conclusions: Results suggest that coffee consumption might be slightly beneficial to memory in elderly but lacks a dose response relationship. Longitudinal analyses are needed to investigate possible, even if subtle, positive effects of coffee drinking on specific cognitive domains in elderly. Full article