Category and letter fluency tasks are commonly used clinically to investigate the semantic and phonological processes central to speech production, but the neural correlates of these processes are difficult to establish with functional neuroimaging because of the relatively unconstrained nature of the tasks. This study investigated whether differential performance on semantic (category) and pho...

Changes of cognitive function in PD have been extensively documented and defined as a 'frontal' type executive dysfunction. One of the main components of this executive dysfunction is the impairment of verbal fluency. The aim of the present study was to assess semantic and phonemic fluency in a large sample of PD patients and to investigate the effect of clinical and sociodemographic variables ...

The strategies used to perform a verbal fluency task appear to be reflective of cognitive abilities necessary for successful daily functioning. In the present study, we explored potential differences in verbal fluency strategies (switching and clustering) used to maximize word production by patients with relapsing-remitting multiple sclerosis (RRMS) versus patients with secondary progressive mu...

This study examined the relationships between regional brain volumes and semantic, phonological, and nonverbal fluency in 32 participants with Alzheimer's disease (AD). Object but not animal semantic fluency correlated with frontal and temporal gray matter volumes. Phonological fluency was not significantly associated with any brain volume examined. Nonverbal fluency was selectively associated ...

Background: Finding the right word is a necessity in communication, and its evaluation has always been a challenging clinical issue, suggesting the need for valid and reliable measurements. The Homophone Meaning Generation Test (HMGT) can measure the ability to switch between verbal concepts, which is required in word retrieval. The purpose of this study was to adapt and validate the Persian ve...

Verbal fluency tasks have been identified as important indicators of executive functioning impairment in patients with frontal lobe dysfunction. Although the usual evaluation of this ability considers phonologic and semantic criteria, there is some evidence that fluency of verbs would be more sensitive in disclosing frontostriatal physiopathology since frontal regions primarily mediate retrieva...

We used multidimensional statistical procedures to study semantic and lexical processes underlying word retrieval in verbal-fluency performance. Forty healthy participants were given a two-choice letter task (i.e., generate items beginning with the letter 'A' or 'F', in any order) and a two-choice category task (i.e., generate animal or fruit names, in any order). Using correspondence analysis ...

Two underlying components of verbal fluency tasks have been identified as clustering (the ability to generate successive words within a sub-category) and switching (the ability to shift from one sub-category to another). Selective impairment of switching ability occurs in patients with frontostriatal pathology, whilst clustering ability is compromised with temporal lobe dysfunction. Letter flue...

INTRODUCTION A prominent view in the neuropsychological literature is that schizophrenia is particularly associated with executive dysfunction, yet in a meta-analytic review it was concluded that, relative to their general level of intellectual functioning, schizophrenics are not disproportionately impaired on a measure of this construct, the Wisconsin Card Sorting Test (WCST). However, verbal ...

INTRODUCTION Formal thought disorder is a hallmark feature of schizophrenia in which disorganized thoughts manifest as disordered speech. A dysfunctional semantic system and a disruption in executive functioning have been proposed as possible mechanisms for formal thought disorder and verbal fluency impairment. Traditional rating scales and neuropsychological test scores might not be sensitive ...