while parkinson's disease (pd) has traditionally been defined by motor symptoms, many researches have indicated that mild cognitive impairment is common in non-demented pd patients. the purpose of this study was to compare verbal fluency performance in non-demented parkinson's disease patients with healthy controls.in this cross-sectional study thirty non-demented parkinson's disease patients a...

Age-related macular degeneration (AMD), the leading cause of blindness in developed nations, has been associated with poor performance on tests of phonemic fluency. This pilot study sought to (1) characterize the relationship between phonemic fluency and resting-state functional brain connectivity in AMD patients and (2) determine whether regional connections associated with phonemic fluency in...

A meta-analysis of 153 studies with 15,990 participants was conducted to compare the magnitude of deficits upon tests of phonemic and semantic fluency for patients with dementia of the Alzheimer's type (DAT) relative to healthy controls. As has been found for patients with focal temporal cortical lesions (but not for patients with focal frontal cortical lesions), DAT patients were significantly...

Although verbal fluency is a frequently used neuropsychological test, little is known about the underlying cognitive processes. The authors proposed that 2 important components of fluency performance are clustering (i.e., the production of words within semantic or phonemic subcategories) and switching (i.e., the ability to shift between clusters). In Experiment 1, correlational data from 54 old...

A meta-analysis of 31 studies with 1,791 participants was conducted to investigate the sensitivity of tests of verbal fluency to the presence of focal cortical lesions. Relative to healthy controls, participants with focal frontal injuries had large and comparable deficits on phonemic (r = .52) and semantic (r = .54) fluency. For frontal but not nonfrontal patients, phonemic fluency deficits qu...

In a meta-analysis of 135 studies involving 6000 patients with Alzheimer's disease (AD) and 6057 healthy controls, we examined the relative degree of semantic and phonemic fluency impairment in AD patients. The effect size for semantic fluency (d=2.10: 95%CI 2.22-1.97) was significantly larger than for both phonemic fluency (d=1.46: 95%CI 1.56-1.36) and picture naming (d=1.54: 95%CI 1.66-1.40)....

Subthalamic nucleus deep brain stimulation (STN-DBS) is a surgical technique to treat motor symptoms in patients with Parkinson's disease (PD). Studies have shown that STN-DBS may cause a decline in verbal fluency performance. We aimed to verify the effects of STN-DBS on the performance of phonemic verbal fluency in Brazilian PD patients. Sixteen participants were evaluated on the Unified Parki...

Disproportionately greater deficits in semantic relative to phonemic verbal fluency are seen in Alzheimer's disease (AD) and have been attributed to neurodegenerative changes in the temporal lobe. Amnestic (AMN) mild cognitive impairment (MCI), which often represents incipient AD, is also characterized by early temporal lobe neuropathology, but previous comparisons of verbal fluency between AD ...