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Between group differences in clustering and switching in SVF Animals and Vegetables in subsample of patients.
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Patients with subjective cognitive decline (SCD) are at higher risk for conversion to dementia due to Alzheimer’s disease (AD). Semantic verbal fluency (SVF) seems to be impaired in the early stages of AD. The goal of the present study was to identify the discriminative potential of verbal fluency (VF) in patients with SCD to show if very early sig...
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Context 1
... was consis- tent with differences found in SVF vegetables between NC and SCD groups. Table 3 shows demographic characteristics of NC (n ¼ 30) and SCD (n ¼ 33) subsamples and comparison of these subsamples in given SVF scores. NC and SCD subsamples significantly differed in the number of switches and cluster size in SVF animals. ...
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Background:
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Citations
... Finally, studies used tests of verbal fluency to examine lexical access and executive functions in SCD. Overall, the authors found lower performance of participants with SCD compared to participants without cognitive complaints (Açikgöz et al., 2014;López-Higes et al., 2017;Macoir et al., 2019Macoir et al., , 2022Nikolai et al., 2018;Nutter-Upham et al., 2008). ...
... Mixed results have been reported in studies using semantic fluency. Some reported impairments in SCD compared to healthy controls (Açikgöz et al., 2014;Elkana et al., 2016;Kielb et al., 2017;Koppara et al., 2015;López-Higes et al., 2017;Minett et al., 2008;Nikolai et al., 2018), while others (Caramelli & Beato, 2008;De Simone et al., 2023) found no difference between the groups. There is a similar discrepancy in studies of phonemic fluency tasks in SC, with studies reporting differences between SCD and HC groups (Koppara et al., 2015;López-Higes et al., 2017) and others not (De Simone et al., 2023;Nutter-Upham et al., 2008;Park et al., 2019). ...
Subjective cognitive decline (SCD) may serve as an early indicator of Alzheimer's disease (AD). However, accurately quantifying cognitive impairment in SCD is challenging, mainly because existing assessment tools lack sensitivity. This study examined how tasks specifically designed to assess knowledge of famous people, could potentially aid in identifying cognitive impairment in SCD. A total of 60 adults with SCD and 60 healthy controls (HCs) aged 50 to 82 years performed a famous people verbal fluency task and a famous people naming task. In the famous people fluency task, the results showed that the individuals with SCD produced significantly fewer famous names in the total time allowed than the HCs, and this difference was also found in the first and the second time interval. In the famous people naming task, the performance of the SCD group was significantly lower than that of the HC group only in the more recent period of fame. Overall, these results suggest that retrieving the names of famous people was more difficult for people with SCD than for people without cognitive complaints. They also suggest that famous people verbal fluency and naming tasks could be useful in detecting cognitive decline at the preclinical stage of AD.
... These changes could characterize the transition to full-blown disease 56 . In particular, the tendency of subjects who later developed dementia to form smaller clusters could support the hypothesis of disorganization of lexical representations 57 . ...
Patients with amnestic mild cognitive impairment (aMCI) are at a higher risk of converting to Alzheimer's disease. The aim of this study was to examine the potential use of Verbal Fluency (VF) measures as markers for predicting the conversion to dementia. At baseline, 61 aMCI, aged 65 to 80 years, underwent a comprehensive neuropsychological assessment, including phonemic (PVF) and semantic verbal fluency (SVF) tasks. After 18 months, 14 individuals with aMCI had progressed to a diagnosis of dementia. The findings revealed that aMCI-converter group had lower Mini Mental State Examination and Rey Auditory Verbal Learning Task scores than aMCI-no converter and produced fewer clusters in both VF tasks and a lower number of switches in PVF at baseline (p < 0.05). According to receiver operating characteristic curve analysis, the number of clusters in PVF had the highest predictive value (AUC = 0.80) with a threshold of 5.510 for identifying aMCI-converter at baseline. Additionally, participants with higher levels of education exhibited more clusters and switches in VF tasks (p < 0.05). These results suggest that qualitative measures of VF could serve as neuropsychological markers for predicting cognitive decline in individuals with aMCI. Furthermore, the study highlights the potential influence of the education level on cognitive performance in neuropsychological tasks.
... On the other hand, some studies have stated that in general, expressive language function is impaired in mild cognitive impairment and Alzheimer's disease, as is verbal fluency (Murphy et al, 2006;Price et al, 2012;Weakley et al, 2013;Nikolai et al, 2018), writing (Tsantali (Ahmed et al, 2008;Frings et al, 2011;Noroozian et al, 2018), word and picture description (Taler and Phillips, 2008;Tsantali et al, 2013) and oral reading (Taler and Phillips, 2008;Tsantali et al, 2013). In the present study, both the mild cognitive impairment and Alzheimer's disease groups had reduced scores in semantic verbal fluency, oral reading, letter verbal fluency, writing sentences, confrontation naming, picture description, and word description after 6 months, compared to each other as well as the control group. ...
Background/Aims
Language changes are the earliest signs and symptoms of mild cognitive impairment and Alzheimer's disease. The aim of this study was to explore the language difference performance between people with mild cognitive impairment, people with Alzheimer's disease and healthy individuals as a control group. To accomplish this aim, the language profile of both mild cognitive impairment and Alzheimer's disease needs to be characterised to determine which feature is more affected by both mild cognitive impairment and Alzheimer's disease among expressive language, receptive language, executive function and memory performance.
Methods
This case-control prospective study involved 90 participants. The Mini-Mental Status Examination and the Functional Assessment Staging Tool were used to classify the participants into three groups: people with mild cognitive impairment, people with Alzheimer's disease and healthy individuals as a control group. Then, the language performance of patients in the mild cognitive impairment and Alzheimer's disease groups was investigated and compared with those of the control group by using the Barnes Language Assessment. The groups were reassessed 6 months later to see if there was any change in language ability.
Results
The results showed that the mild cognitive impairment group and Alzheimer's disease group had significant decreases in expressive language (P>0.01), executive function (P>0.01), receptive language (P>0.01) and memory skills (P>0.01) from baseline to the reassessment at 6 months.
Conclusions
Language deficits, especially expressive language deficits, could appear before impairment in executive function, receptive language and verbal episodic memory in participants with mild cognitive impairment or Alzheimer's disease. Speech and language therapists can use the findings of this study to design and implement treatment programmes.
... As in the memory domain, the results have been mixed. Additionally, some research has found associations between greater general SCCs and poorer language performance Macoir et al., 2019;Nikolai et al., 2018). These findings highlight the clinical relevance of assessing language performance but do not provide information on the validity of SLCs as opposed to SCCs. ...
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.
... Results were considered statistically significant at p < 0.05. (71). Moreover, the absence of extensive cognitive differences between the two groups was not unexpected. ...
IntroductionSubjective Cognitive Decline (SCD) can progress to mild cognitive impairment (MCI) and Alzheimer’s disease (AD) dementia and thus may represent a preclinical stage of the AD continuum. However, evidence about structural changes observed in the brain during SCD remains inconsistent.Materials and methodsThis cross-sectional study aimed to evaluate, in subjects recruited from the CompAS project, neurocognitive and neurostructural differences between a group of forty-nine control subjects and forty-nine individuals who met the diagnostic criteria for SCD and exhibited high levels of subjective cognitive complaints (SCCs). Structural magnetic resonance imaging was used to compare neuroanatomical differences in brain volume and cortical thickness between both groups.ResultsRelative to the control group, the SCD group displayed structural changes involving frontal, parietal, and medial temporal lobe regions of critical importance in AD etiology and functionally related to several cognitive domains, including executive control, attention, memory, and language.Conclusion
Despite the absence of clinical deficits, SCD may constitute a preclinical entity with a similar (although subtle) pattern of neuroanatomical changes to that observed in individuals with amnestic MCI or AD dementia.
... Promising results have emerged from studies using verbal fluency tests, which explore lexical access and executive functions. For example, a few studies have shown that, compared to the HCs, individuals with SCD generated significantly fewer words during semantic and/or orthographic verbal fluency tasks [28][29][30]. In addition, we recently identified a continuum of performance on a free action (verb) fluency task; the HCs performed better than the participants with SCD, who, in turn, performed better than the participants with MCI [31]. ...
... Verbal fluency tasks are used in clinical practice and research to measure the speed of lexical access as well as executive functions, especially updating, inhibition, and mental flexibility [58,59]. Impaired performance in verbal fluency has been reported in SCD research in which classical semantic and orthographic fluency tasks were used; however, some studies obtained inconsistent or inconclusive results [28][29][30][60][61][62]. For example, Nutter-Upham et al. reported a HC > SCD > MCI continuum of performance in verbal fluency but did not detect a statistical difference between the participants with SCD and the HCs [29]. ...
... Fagundo et al. and Östberg et al. found significant differences in verbal fluency between the participants with SCD, MCI, and AD; however, the absence of a control group in each study made it impossible to assess the decline in SCD [60,61]. Nikolai et al. showed that, compared to the HCs, the participants with SCD generated significantly fewer words in semantic tasks but not in orthographic fluency tasks [28]. ...
Objective:
Although evidence has indicated that subjective cognitive decline (SCD) may be an early sign of Alzheimer's disease (AD), the objectification of cognitive impairment in SCD is challenging, mainly due to the lack of sensitivity in assessment tools. The present study investigated the potential contribution of two verbal fluency tasks with high executive processing loads to the identification of cognitive impairment in SCD.
Methods:
A total of 60 adults with SCD and 60 healthy controls (HCs) performed one free action (verb) fluency task and two fluency tasks with more executive processing load-an alternating fluency task and an orthographic constraint fluency task-and the results were compared.
Result:
In the free action fluency task, the performance of the participants with SCD and the HCs was similar. However, HCs performed significantly better than SCD in the alternating fluency task, which required mental flexibility, and the orthographic constraint fluency task, which required inhibition.
Discussion:
The study findings suggest that verbal fluency tasks with high executive processing load could be useful in detecting cognitive deficits at the preclinical stage of AD. The inclusion of such tests in assessment batteries should be considered in order to improve the detection of subtle cognitive impairment in preclinical major neurocognitive disorder populations.
... For example, measures derived from tests of associative memory (Kormas et al., 2020;Sanabria et al., 2018), memory binding (Koppara et al., 2015;Markova et al., 2022) and semantic interference Matias-Guiu et al., 2018) seeming to be better indicators of SCD or biomarker-defined preclinical AD and are also more predictive of progression to MCI or AD dementia (Mowrey et al., 2016(Mowrey et al., , 2018 than traditional neuropsychological scores. Promising results in this field have also been reported for measures of discrepancy between semantic and phonological word fluency (Nikolai et al., 2018;Vonk et al., 2020) and tests assessing spatial memory (Coughlan et al., 2020;Poos et al., 2021;Webb et al., 2020). However, more data are needed to develop reliable instruments for use in clinical practice. ...
Objective: Subjective cognitive decline (SCD) was recently proposed as an early risk factor for future mild cognitive impairment and Alzheimer’s disease (AD). In this study, we investigated the sensitivity of novel neuropsychological testing paradigms (which have been proposed as potentially challenging tools for the identification of preclinical AD) in capturing the subtle cognitive changes leading to SCD but not objectively detected by traditional tests. Method: The performances of 18 patients with SCD and 15 healthy individuals with no worries of cognitive decline (healthy controls [HC]) was compared on demanding tasks that investigated, respectively, associative memory, memory binding, spatial pattern separation processes and semantic memory. The diagnostic utility of these tests in capturing the subtle cognitive changes associated with SCD and possible relationships with SCD-related worries were investigated. Results: No significance between-group difference was found on the standard neuropsychological tests. Conversely, the performance of patients with SCD and HC differed significantly on specific indexes derived from experimental tasks assessing face–name associative memory and spatial pattern separation. Moreover, these measures correctly classified group membership with good overall accuracy (between 79% and 82%) and were significantly associated with self-perceived memory functioning. Conclusions: Our preliminary findings suggest that specific measures derived from demanding cognitive paradigms could be sensitive neuropsychological indexes for detecting the subtle cognitive impairment associated with SCD. These observations could be useful for further refining cognitive assessment aimed at early detection of AD.
... This is analogous to the previous results showing semantic fluency to predict incident dementia even when controlling for memory test scores [53] and brings other arguments that deficits in semantic fluency may constitute a dysnomic aMCI phenotype that progresses to dementia more quickly than memory impairment alone [26]. It has been previously shown that semantic fluency is greatly reduced in early stages of AD [24,25,[54][55][56], qualitatively impaired already in patients with subjective cognitive decline [57], and the predictive power to predict future conversion to dementia in MCI patients was only slightly inferior to memory tests [58]. At the functional level, the impairment of semantic fluency in AD is probably caused mainly by the degradation of semantic knowledge and impairment of associations between concepts in semantic knowledge manifesting as reduced cluster size [59]. ...
Background:
Memory tests using controlled encoding and cued recall paradigm (CECR) have been shown to identify prodromal Alzheimer's disease (AD), but information about the effectiveness of CECR compared to other memory tests in predicting clinical progression is missing.
Objective:
The aim was to examine the predictive ability of a memory test based on the CECR paradigm in comparison to other memory/non-memory tests for conversion to dementia in patients with amnestic mild cognitive impairment (aMCI).
Methods:
270 aMCI patients from the clinical-based Czech Brain Aging Study underwent a comprehensive neuropsychological assessment including the Enhanced Cued Recall test (ECR), a memory test with CECR, two verbal memory tests without controlled encoding: the Auditory Verbal Learning Test (AVLT) and Logical memory test (LM), a visuospatial memory test: the Rey-Osterrieth Complex Figure test, and cognitive testing based on the Uniform Data Set battery. The patients were followed prospectively. Conversion to dementia as a function of cognitive performance was examined using Cox proportional hazard models.
Results:
144 (53%) patients converted to dementia. Most converters (89%) developed dementia due to AD or mixed (AD and vascular) dementia. Comparing the four memory tests, the delayed recall scores on AVLT and LM best predicted conversion to dementia. Adjusted hazard ratios (HR) of immediate recall scores on ECR, AVLT, and LM were similar to the HR of categorical verbal fluency.
Conclusion:
Using the CECR memory paradigm in assessment of aMCI patients has no superiority over verbal and non-verbal memory tests without cued recall in predicting conversion to dementia.
... Semantic verbal fluency; mild cognitive impairment; multidimensional scaling; lexical-semantic features; semantic map Verbal fluency tasks are usually included in neuropsychological protocols to assess language and executive functions in healthy older adults, as well as in patients with subjective cognitive decline (Nikolai et al., 2018), mild cognitive impairment (MCI; Price et al., 2012) and Alzheimer's disease (AD; Herbert et al., 2014). Verbal fluency tasks have two typical modalities, phonological (producing words beginning with the same letter/phoneme), and semantic (SVF) (evoking words belonging to a semantic category, for example: animals, fruits, tools, etc.). ...
Introduction: Semantic verbal fluency is a useful neuropsychological tool since it involves language and executive abilities that can be impaired in patients with neurodegenerative diseases in comparison to healthy controls. The present study explores retrieve and executive control processes using traditional quantitative and qualitative raw scores and examines the utility of multidimensional scaling combined with linear regression to provide new insights about the underlying semantic network in mild cognitive impairment and in healthy older adults.
Method: A total of 165 Spanish older adults, 81 patients and 84 controls, were assessed in different cognitive domains and evoked animal names in one minute. Group differences on fluency raw scores were first explored. Regressions using tests to predict groups’ fluency scores were also performed. The 12 animals that had been produced more frequently were selected to perform a multidimensional scaling analysis for each group. Four features related to animal names were extracted from normative studies and then were used as predictors in linear regression to provide an interpretation of the resulting dimensions’ coordinates.
Results: Patients performed worse on memory and naming and produced a shorter list of animals than controls. In controls, naming and visual memory explained a small part of variance related to the total of animals produced and to the number of switches. Both groups exhibited similar semantic maps.
Conclusions: Results suggest that patients’ map is influenced by words with a dense associative neighborhood that were acquired at an early age, whereas in controls none of the predictors explained dimensions.
... In contrast, regarding the phonemic fluency tests, differences were only observed in the case of the 'a' phonemic fluency, where two temporal parameters (the average and total length of irrelevant utterances) and one of the traditional measures (incorrect words) showed significant difference. These results are consistent with those of earlier studies, confirming that semantic fluency tasks may be more appropriate for detecting the cognitive changes that occur in MCI (McDonnell et al., 2020;Nikolai et al., 2018). Furthermore, when compared to other subtypes of semantic fluency tests (plants, clothes, vehicles), the animal fluency test has previously shown the highest sensitivity (98.8%) in discriminating between HC and MCI participants (García-Herranz et al., 2020). ...
Objective
Most recordings of verbal fluency tasks include substantial amounts of task-irrelevant content that could provide clinically valuable information for the detection of mild cognitive impairment (MCI). We developed a method for the analysis of verbal fluency, focusing not on the task-relevant words but on the silent segments, the hesitations, and the irrelevant utterances found in the voice recordings.
Methods
Phonemic (‘k’, ‘t’, ‘a’) and semantic (animals, food items, actions) verbal fluency data were collected from healthy control (HC; n = 25; M age = 67.32) and MCI ( n = 25; M age = 71.72) participants. After manual annotation of the voice samples, 10 temporal parameters were computed based on the silent and the task-irrelevant segments. Traditional fluency measures, based on word count (correct words, errors, repetitions) were also employed in order to compare the outcome of the two methods.
Results
Two silence-based parameters (the number of silent pauses and the average length of silent pauses) and the average word transition time differed significantly between the two groups in the case of all three semantic fluency tasks. Subsequent receiver operating characteristic (ROC) analysis showed that these three temporal parameters had classification abilities similar to the traditional measure of counting correct words.
Conclusion
In our approach for verbal fluency analysis, silence-related parameters displayed classification ability similar to the most widely used traditional fluency measure. Based on these results, an automated tool using voiced-unvoiced segmentation may be developed enabling swift and cost-effective verbal fluency-based MCI screening.
