Impairment in category fluency in ischemic vascular dementia.

Abstract

The underlying mechanisms for impaired output on letter (F, A, and S) and category (e.g., animal) word list generation (WLG) tasks in subcortical ischemic vascular dementia (IVD) were investigated. Normal control (NC) and Alzheimer's disease (AD) participants were also studied. IVD and NC participants performed better on category than letter WLG tasks, whereas the opposite was observed among AD participants. IVD participants produced fewer responses than AD participants on letter WLG tasks, but there was no difference between AD and IVD participants on the "animal" WLG task. AD participants scored lower than IVD and NC participants on animal WLG indexes measuring semantic knowledge. There were few differences between IVD and NC participants. The reduced output on the animal WLG task for IVD participants is consistent with search-retrieval deficits. The reduced output of AD participants may be caused by degraded semantic knowledge.

Distinguishing between Vascular Dementia and Alzheimer's Disease by Means of the WAIS: A Meta-analysis

“…Both tests are occasionally referred to as measuring EF, although letter fluency is acknowledged as the most pure form of EF whereas category fluency is often denoted as a test of semantic memory. Interestingly, a dissociation between letter and category fluency tests in VaD and AD patients exists, in that AD patients perform worse on category compared to letter fluency (Carew, Lamar, Cloud, Grossman & Libon, 1997;Henry, Crawford & Phillips, 2004;Monsch et al, 1997) whereas the opposite is found in VaD patients (Carew et al, 1997). Possibly, this dissociation might also be present with respect to the Wechsler subtests, but for now it remains speculative.…”

The heterogeneity of mild cognitive impairment: A neuropsychological analysis

“…Performance on most nonmemory tests was largely intact except for comparatively low output on the "animal" fl uency test. Low output on semantically guided fl uency tests in a group of individuals with anterograde amnesia might suggest the presence of concomitant semantic memory defi cits (Adlam, Bozeat, Arnold, Watson, & Hodges, 2006 ;Carew et al, 1997 ;Dudas, Clague, Thompson, Graham, & Hodges, 2005 ;Murphy, Rich, & Troyer, 2006 ). Howieson at al.…”

“…Lexical retrieval/naming was assessed with the 60-item version of the Boston Naming Test (BNT; Kaplan, Goodglass, & Weintraub, 1983 ), and a test of semantic fl uency ("animals"; Carew, Cloud, Lamar, Grossman, & Libon, 1997 ;Monsch, Bondi, Butters, Salmon, Katzman, & Thal, 1992). The dependent variable derived from the BNT was the number of correct responses.…”

Organization of semantic category exemplars in schizophrenia

“…In the original, participants arranged animal names mounted on dowels so that closer proximity reflected greater similarity and the examiner measured the distance between labels. We also quantified the degree of semantic feature sharing between our animal exemplars by incorporating a published scoring system (Giovannetti Carew et al, 1997;Moelter et al, 2001). Each animal was scored on six semantic attributes (size, geographic location, diet, zoological class, habitat, and zoological families or groupings) and the number of shared attributes between pairs was computed (see Appendix A).…”

“…Each animal was scored on six semantic attributes (size, geographic location, diet, zoological class, habitat, and zoological families or groupings) and the number of shared attributes between pairs was computed (see Appendix A). Reductions in the number of shared attributes between consecutive animal fluency responses has been associated with semantic memory deficits in Alzheimer's disease and left temporal lobe epilepsy (Giovannetti Carew et al, 1997;Giovannetti et al, 2003).…”