On Which Abilities Are Category Fluency and Letter Fluency Grounded A Confirmatory Factor Analysis of 53 Alzheimer's Dementia Patients

Abstract

Background/Aims: In Alzheimer's dementia (AD), letter fluency is less impaired than category fluency. To check whether category fluency and letter fluency depend differently on semantics and attention, 53 mild AD patients were given animal and letter fluency tasks, two semantic tests (the Verbal Semantic Questionnaire and the BORB Association Match test), and two attentional tests (the Stroop Colour-Word Interference test and the Digit Cancellation test). Methods: We conducted a LISREL confirmatory factor analysis to check the extent to which category fluency and letter fluency tasks were related to semantics and attention, viewed as latent variables. Results: Both types of fluency tasks were related to the latent variable Semantics but not to the latent variable Attention. Conclusions: Our findings warn against interpreting the disproportionate impairment of AD patients on category and letter fluency as a contrast between semantics and attention.

Dissociating Semantic and Phonemic Search Strategies in the Phonemic Verbal Fluency Task in early Dementia

“…However, there is conflicting research that PVF taps into the semantic network, although to a lesser extent than semantic fluency (Lezak et al, 2004;Mueller et al, 2015;Schmidt et al, 2017;Clark et al, 2013). Bizzozero et al (2013) investigated the extent to which SVF and PVF were related to semantic and attention processes and found evidence of semantic processes in both SVF and PVF. Nutter-Upham et al (2008) observed a larger effect size for the amnestic MCI (aMCI) group's deficit on semantic verbal fluency (Cohen's d=0.98) than for their deficit on phonemic verbal fluency (Cohen's d=0.66), due to greater variability in phonemic verbal fluency performance.…”

Contribution of the Cerebellum and the Basal Ganglia to Language Production: Speech, Word Fluency, and Sentence Construction—Evidence from Pathology

“…Category fluency is largely based on an automatic search in the lexical semantic system that might help organize a list of semantic items, e.g., a shopping list, in an ecological context [131]. Letter fluency, by contrast, requires greater attention because it requires an active lexical search based on the given phoneme without any contextual associative support [132]. Clinically, category fluency is considered an indicator of lexical-semantic integrity, whereas letter fluency is currently used as a measure of executive abilities in which the active lexical search requires keeping and monitoring information in the working memory system.…”

Construct validity of the Free and Cued Selective Reminding Test in older adults with memory complaints

“…The following measures were selected, in order to test discriminant validity, representing constructs distinct from episodic memory: Word Fluencies (letter fluency [LF; Carlesimo et al ., ] and category fluency [CF; Novelli et al ., ]), which require the generation of word lists, have proven to be sensitive indicators of lexical–phonological functions and cognitive flexibility. CF is largely based on semantic processing, whereas attention and lexical knowledge have an heavier role in LF (Bizzozero et al ., ). The RCF copy (Caffarra, Vezzadini, et al ., ) investigates perceptual organization, constructional praxis, and copy strategy. The Clock Drawing Test (CDT; Sunderland et al., ) requires different cognitive abilities, including visuospatial abilities, abstract conceptualization, and executive control. The Raven Coloured Progressive Matrices 47 (CPM47; Measso et al ., ) requires the capacity of hypothesis generation and abstract reasoning. The Trail Making Test (TMT) (part A; Giovagnoli et al ., ) assesses the capacity for visual search, psychomotor speed and attention. The Frontal Assessment Battery (FAB; Appollonio et al ., ) consists of a set of tests exploring conceptualization, item generation, motor sequencing, sensitivity to interference, inhibitory control, and environmental autonomy. The Stroop Colour‐Word Test (SCWT; Caffarra, Dieci, Zonato, and Venneri, ) requires the ability to shift concepts and to inhibit automatic responses. Scoring is based on time and number of errors. …”

“…Word Fluencies (letter fluency [LF; Carlesimo et al, 1996] and category fluency [CF; Novelli et al, 1986]), which require the generation of word lists, have proven to be sensitive indicators of lexical-phonological functions and cognitive flexibility. CF is largely based on semantic processing, whereas attention and lexical knowledge have an heavier role in LF (Bizzozero et al, 2013). The RCF copy (Caffarra, Vezzadini, et al, 2002) investigates perceptual organization, constructional praxis, and copy strategy.…”