Verbal fluency in relation to reading ability in students with and without dyslexia

In Alzheimer’s dementia (AD), greater declines in semantic fluency (SF) relative to letter fluency (LF) have been assumed to reflect semantic disintegration. However, the same pattern is observed in typical aging and neurodegenerative disorders besides AD. We examined this assumption by comparing different aspects of SF and LF performance in older adults with and without dementia, and identifying which verbal fluency measures most clearly distinguish AD from typical aging. Verbal fluency data were compared from 109 individuals with AD and 66 typically aging adults. Correct items, clusters, and errors were analyzed using both raw counts and proportions. Regression analyses examined Task-by-Group interactions and the impact of demographic variables on verbal fluency measures. ROC analyses examined the sensitivity and specificity of the different outcome measures. In regressions, interactions were found for raw but not proportional data, indicating that different group patterns were driven largely by the number of correct items produced. Similarly, in ROC analyses, raw SF totals showed stronger discriminability between groups than either raw discrepancy scores (SF–LF) or discrepancy ratios (SF/LF). Age and cognitive status (MMSE) were the strongest individual predictors of performance. Findings suggest that AD entails quantitative declines in verbal fluency, but qualitatively similar patterns of performance relative to typically aging adults. Thus, SF declines in AD seem to be at least partially attributable to an exaggeration of the underlying mechanisms common to typical aging, and do not necessarily implicate semantic disintegration.

Action (verb) fluency is a newly developed verbal fluency task that requires the examinee to rapidly generate as many verbs (i.e., "things that people do") as possible within 1 min. Existing literature indicates that action fluency may be more sensitive to frontal-basal ganglia loop pathophysiology than traditional noun fluency tasks (e.g., animal fluency), which is consistent with the hypothesized neural dissociation between noun and verb retrieval. In the current study, a series of analyses were undertaken to examine the psychometric properties of action fluency in a sample of 174 younger healthy participants. The first set of analyses describes the development of demographically adjusted normative data for action fluency. Next, a group of hypothesis-driven correlational analyses reveals significant associations between action fluency and putative tests of executive functions, verbal working memory, verbal fluency, and information processing speed, but not between action fluency and tests of learning or constructional praxis. The final set of analyses demonstrates the test-retest stability of the action fluency test and provides standards for determining statistically reliable changes in performance. In sum, this study enhances the potential clinical applicability of action fluency by providing demographically adjusted normative data and demonstrating evidence for its reliability and construct validity.

Semantic verbal fluency is usually administered as a screening test for dementia in clinical settings. The most common categories used are animal and fruits. Recently, there has been an increasing interest in the performance of MCI subjects in verbal fluency tests and how these tools can contribute in the early detection of cognitive decline. Our aim is to evaluate which categories best contribute to the differential diagnosis between CCL x normal elderly. Cross-sectional assessment of 60 patients (30 controls, and 30 MCI) with animal (aVF), fruit (fVF), means of transportation (tVFf), action fluency (acVF), and letter fluency (FAS-COWA), administered as part of a cognitive battery assessment in the work-up for dementia and MCI. There was a statistically difference in the performance of MCI and controls in all categories of verbal fluency employed. The cut off scores obtained in this sample were: aVF:13 (sensitivity: 60%; specificity: 86.7%); fVF:11 (sensitivity: 46.7%; specificity: 90%); tVF: 11 (sensitivity: 66.7%; specificity: 76.7%); acVF: 11 (sensitivity: 56.7%; specificity: 90%) and FAS-COWA: 30 (specificity: 68.3%; specificity: 80%). Logistic regression and ROC curve analyses showed that animal fluency was slightly better in discriminating the two groups, followed by the FAS-COWA VF tasks are valuable screening tools in discriminating MCI from normal elderly; however, animal fluency and FAS-COWA were more effective for such differentiation.

Accumulating evidence indicates action naming may rely more on frontal-subcortical circuits, and noun naming may rely more on temporal cortex. Therefore, noun versus action fluency might distinguish frontal and subcortical dementias from cortical dementias primarily affecting temporal and/or parietal cortex such as Alzheimer's disease (AD). We hypothesized patients with subcortical dementia, e.g., normal pressure hydrocephalus (NPH) and patients with dementias predominantly affecting frontal cortex, e.g., behavioral variant frontotemporal dementia (bv-FTD) and progressive nonfluent aphasia (PNFA) have more difficulty on action fluency versus noun fluency (e.g., animal naming). Patients with AD, who have temporo parietal cortical dysfunction, should have more difficulty on noun versus verb fluency. A total of 234 participants, including healthy controls (n = 20) and patients diagnosed with NPH (n =144), AD (n = 33), bv-FTD (n = 22) or PNFA (n =15) were administered animal fluency, action fluency, and letter fluency tasks, and the Mini-Mental State Examination (MMSE, to control for dementia severity). NPH and bv-FTD/PNFA patients had significantly higher MMSE scores and animal fluency than AD patients (after adjusting for age), but their action fluency tended to be lower than in AD. Only NPH and bvFTD/PNFA patients showed significantly lower action verb than animal fluency. Results provide novel evidence that action naming relies more on frontal-subcortical circuits while noun naming relies more on temporoparietal cortex, indicating action verb fluency may be more sensitive than noun fluency, particularly for detecting frontal-subcortical dysfunction.

BackgroundEvidence is emerging that subtle language decline is an early indicator of Alzheimer’s disease (AD). This study assessed change in semantic and letter fluency in individuals with subjective cognitive decline (SCD), and examined whether trajectories differed between individuals with and without amyloid‐beta (Aβ)‐pathology.MethodLongitudinal data from 437 individuals of the memory clinic‐based Amsterdam Dementia Cohort were included (Age 61±8 years, 184(42%) Female, follow‐up time 5.3±3.7 years; Table 1). Participants were classified as SCD at baseline, had available baseline Aβ‐information and had at least 1 follow‐up on semantic or letter fluency. Baseline Aβ‐status was dichotomized as positive/negative based on local cut‐offs for Aβ1‐42 concentrations in cerebrospinal fluid, or visual inspection of amyloid positron emission tomography‐imaging (Florbetapir or PiB). Two linear mixed models (LMM) were used to investigate change on semantic and letter fluency. Models included time and time*Aβ‐status as predictors of interest, a random intercept for participant, and age, sex, education were adjusted for. LMMs were subsequently stratified for Aβ‐status.ResultAt baseline, the groups did not differ in semantic (p = 0.313) or letter fluency (p = 0.294). Over time Aβ‐positive individuals changed more rapidly on semantic fluency compared to Aβ‐negative individuals (β = ‐0.32,CI = ‐0.49 – ‐0.14;p<.001). The Aβ‐positive group declined with 0.35 words per year (CI = ‐0.49 – ‐0.20;p<.001), while Aβ‐negative individuals did not show change (β = 0.03;CI = ‐0.12 – 0.06;p = 0.496) (Figure 1). On letter fluency Aβ‐positive individuals changed differently compared to Aβ‐negative individuals (β = ‐0.38;CI = ‐0.72 – ‐0.04;p = 0.028), to the extent that the Aβ‐positive group did not progress (β = 0.10;CI = ‐0.21 – 0.41;p = 0.533), while Aβ‐negative individuals improved with 0.47 words per year (CI = 0.29 – 0.65;p<.001) (Figure 2).ConclusionOur results indicate that Aβ‐positive individuals decreased on semantic fluency, but remained stable on letter fluency. In contrast, Aβ‐negative individuals remained stable on semantic fluency, while they improved on letter fluency over time, which might suggest a learning effect. These findings suggest that the presence of Aβ‐pathology is characterized by semantic loss, highlighting the potential of language based performance as a biomarker for Aβ‐pathology in SCD.

The functional organization and related anatomy of executive functions are still largely unknown and were examined in the present study using a verbal fluency task. The objective of this study was to determine the cognitive architecture of a fluency task and related voxelwise anatomy in the GRECogVASC cohort and fMRI based meta-analytical data.First, we proposed a model of verbal fluency in which two control processes, lexico-semantic strategic search process and attention process, interact with semantic and lexico-phonological output processes. This model was assessed by testing 404 patients and 775 controls for semantic and letter fluency, naming, and processing speed (Trail Making test part A). Regression (R2 = .276 and .3, P = .0001, both) and structural equation modeling (CFI: .88, RMSEA: .2, SRMR: .1) analyses supported this model.Second, voxelwise lesion-symptom mapping and disconnectome analyses demonstrated fluency to be associated with left lesions of the pars opercularis, lenticular nucleus, insula, temporopolar region, and a large number of tracts. In addition, a single dissociation showed specific association of letter fluency with the pars triangularis of F3. Disconnectome mapping showed the additional role of disconnection of left frontal gyri and thalamus. By contrast, these analyses did not identify voxels specifically associated with lexico-phonological search processes.Third, meta-analytic fMRI data (based on 72 studies) strikingly matched all structures identified by the lesion approach.These results support our modeling of the functional architecture of verbal fluency based on two control processes (strategic search and attention) operating on semantic and lexico-phonologic output processes. Multivariate analysis supports the prominent role of the temporopolar area (BA 38) in semantic fluency and the F3 triangularis area (BA 45) in letter fluency. Finally, the lack of voxels specifically dedicated to strategic search processes could be due to a distributed organization of executive functions warranting further studies.

The ability to generate words that follow certain constraints, or verbal fluency, is a sensitive indicator of neurocognitive impairment, and is impacted by a variety of variables. To investigate the effect of post-stroke aphasia, elicitation category and linguistic variables on verbal fluency performance. Twenty-eight persons with aphasia (PWA) with a single left-hemisphere lesion and 40 age-matched neurotypical community-dwelling adults were administered three verbal fluency tasks: two semantic (animals and actions) and one phonemic (the letters F, A and S). Data analysis included comparison of total scores, clusters and perseverations. Individual responses were coded for frequency of occurrence, age of acquisition and syllable length to investigate qualitative differences in word generation. PWA performed worse than neurotypical participants across all verbal fluency tasks, and animal fluency scores were farthest from neurotypical performance. PWAs' animal and action fluency were correlated with other language measures, while phonemic fluency was uncorrelated with language measures. While some PWAs showed dissociations between verbal fluency tasks, the dissociations did not pattern along with aphasia fluency. PWAs produced fewer clusters and responses with higher word frequency across all three verbal fluency tasks. Responses had earlier age of acquisition and shorter word length for animal and phonemic fluency, but not action fluency. Verbal fluency, particularly animal fluency, is sensitive to even mild aphasia. PWA produced lexically simpler responses than their neurotypical peers. This study identifies the relevance of qualitative analysis of verbal fluency responses.

The study examined the relationship between phonemic awareness and reading ability in students who are deaf. The research questions were: (a) What is the relationship between phonemic awareness and reading ability in students who are deaf? (b) Does phonemic awareness facilitate the reading development of these students? Participants were 29 children of primary school age enrolled in a residential school for students who are deaf. The dependent variable, reading ability, was measured by a retelling task. The independent variables were age, language ability, and phonemic awareness. Language ability was determined through expert analysis of participant interviews. Phonemic awareness was measured with a word-to-word matching task. Descriptive techniques and multiple regression analysis were employed to analyze the data. Results indicated that reading ability was significantly correlated to language ability, but not to phonemic awareness. Phonemic awareness did not contribute to any of the variance in reading ability. The study results call into question the role of phonemic awareness as a prerequisite for reading development.

Sex differences in lateralization of semantic verbal fluency in temporal lobe epilepsy

This paper reports on a longitudinal study using the computer‐based cognitive assessment system CoPS, and considers the applicability of this system in the early identification of cognitive strengths and limitations that affect the development of reading. CoPS comprises eight tests of basic cognitive abilities, including phonological awareness, auditory discrimination, and short‐term visual and auditory‐verbal memory. A total of 421 children participated in the study. Assessment with the CoPS tests was carried out at age 5 years, and follow‐up assessments using conventional tests of reading and general ability were carried out at 6 and 8 years of age.Correlations between the CoPS tests administered at age 5 and reading ability at age 8 were in the region of 0.6 for auditory‐verbal memory and phonological awareness, and in the region of 0.3 for the CoPS measure of auditory discrimination as well as most of the other memory measures. Stepwise linear regression analyses showed that the CoPS tests of auditory‐verbal memory and phonological awareness administered at age 5 together accounted for 50% of the variance in reading ability at age 8, compared with only 29% of the variance being attributable to intelligence. It was concluded that short‐term memory is an important predictor variable for reading, in addition to the more generally acknowledged variable of phonological processing.Discriminant function analysis showed that CoPS tests provide a highly satisfactory prediction of poor reading skills, with very low or zero rates for false positives and false negatives. By contrast, a word recognition test given at age 6 was not found to predict reading at age 8 to the same degree of accuracy, resulting in an unsatisfactory false positive rate of 21%. Measures of verbal and nonverbal ability at age 6 produced unacceptably high false positive rates between 50% and 70%. These findings are discussed in relation to the prediction of children at risk of reading failure. The potential of computer‐based cognitive profiling for facilitating differentiated teaching in early reading is also considered.

This study aims to compare the word decoding skills, phonological awareness (PA), rapid automatized naming (RAN) skills, and letter knowledge of first graders with developmental dyslexia (DD) and those who were typically developing (TD). Eighteen children with DD and eighteen TD children, matched by nonverbal intelligence and discourse ability, participated in the study. Word decoding of Korean language-based reading assessment(<xref ref-type="bibr" rid="B27">Pae <italic>et al.,</italic> 2015</xref>) was conducted. Phoneme-grapheme correspondent words were analyzed according to whether the word has meaning, whether the syllable has a final consonant, and the position of the grapheme in the syllable. Letter knowledge asked about the names and sounds of 12 consonants and 6 vowels. The children’s PA of word, syllable, body-coda, and phoneme blending was tested. Object and letter RAN was measured in seconds. The decoding difficulty of non-words was more noticeable in the DD group than in the TD one. The TD children read the syllable initial and syllable final position with 99% correctness. Children with DD read with 80% and 82% correctness, respectively. In addition, the DD group had more difficulty in decoding words with two patchims when compared with the TD one. The DD group read only 57% of words with two patchims correctly, while the TD one read 91% correctly. There were significant differences in body-coda PA, phoneme level PA, letter RAN, object RAN, and letter-sound knowledge between the two groups. This study confirms the existence of Korean developmental dyslexics, and the urgent need for the inclusion of a Korean-specific phonics approach in the education system.

Rhythm production in 53 children in grade 1 was investigated as a predictor of reading ability in the same children in grades 1–5. This paper reports the results of correlations and hierarchical regression analyses, controlling for shared variance between phonological awareness and naming speed. Rhythm was correlated significantly with both phonological awareness and naming speed. Rhythm predicted significant variance in reading ability at each grade level. Once phonological awareness was controlled, however, rhythm was a significant predictor only in grade 5. When naming speed was controlled, rhythm predicted unique variance in reading ability in grades 2, 3 and 5. Implications for the relationship between rhythm and the development of reading skills are discussed.

OBJECTIVETo test the hypothesis that semantic impairment is present in both patients with dementia with Lewy bodies (DLB) and those with dementia of Alzheimer's type (DAT).METHODSA comprehensive battery of neuropsychological...

Introduction: Reading impairment in children with dyslexia stems from either a phonological awareness deficit or a deficit in rapid automatized naming. Both deficits constitute the double deficit hypothesis of dyslexia. The aim of the present study was to assess phonological awareness and rapid automatized naming in a group of Greek-speaking children with dyslexia and to correlate their performance in phonological awareness and rapid automatized naming with reading fluency (accuracy and comprehension) scores. Method: Participants were 23 children with a formal diagnosis of dyslexia and 27 typically-developing children with no other learning difficulties or dyslexia. All children were monolingual speakers of Greek and they were administered a naming speed test, a fluency test, a phonological awareness test and reading accuracy and comprehension tasks. Results: Students with dyslexia scored worse in most phonological awareness, rapid automatized naming and reading fluency measures in comparison to their non-dyslexic peers. In addition, students with dyslexia needed more time to complete the rapid automatized naming tests. Positive correlations were found between phonological awareness, rapid automatized naming and reading fluency tests for both groups of students. Specifically, rapid automatized naming and phonological awareness explained 9.3% and 21.8%, respectively, of the variance in the reading fluency of students with dyslexia, while the respective contributions of rapid automatized naming and phonological awareness to the reading fluency for non-dyslexic students were 2% and 9.3%, respectively. Discussion and Conclusion: Phonological awareness and rapid automatized naming can be reliable predictors of reading fluency even in orthographically consistent languages (i.e., Greek), offering support to the double deficit hypothesis. In addition, combining phonological awareness and rapid automatized naming tests seems to be a quick and reliable way to early identify children at risk of reading difficulties in the first grades of primary school.

It is well established that phonological awareness (PA) and rapid automatized naming (RAN) tasks reliably predict children’s developing word reading abilities, across a wide range of languages. However, existing research has not yet demonstrated unequivocally whether RAN and PA are independently and causally linked to reading, nor fully explored the underlying cognitive mechanisms. Most existing research has assessed PA and RAN in children who may already have some reading skill, making direction of influence hard to ascertain. To address this, the current longitudinal research initially assessed RAN and PA in a very young sample of 91 English children (mean age: 3;11; SD = 3.7 months), demonstrated to be non-readers. Children were reassessed on RAN, PA, and word-level reading, 18 months (Time 2) and then a further year later (Time 3). To explore underlying mechanisms, separate measures of reading accuracy and fluency were taken, and reading tasks varied according to the extent to which they required alphabetic decoding and lexical, orthographic knowledge. Path analyses revealed that from Time 1 to Time 2 both RAN and PA predicted word reading, indicating temporal precedence, though there was some degree of reciprocity in these relationships. However, by Time 3, while RAN still predicted accuracy and fluency of reading, PA only predicted reading accuracy. Furthermore, findings suggested that while RAN was robustly related to both alphabetic decoding and lexical, orthographic aspects of reading, PA’s relationship was restricted to alphabetic decoding accuracy. Theoretical and practical implications are discussed.