A predominance of category deficits for living things in Alzheimer's disease and Lewy body dementia

Abstract

Although semantic memory impairment is well documented in patients with dementia of the Alzheimer's type, questions remain as to whether the deficit extends to other forms of dementia and whether it differentially affects different domains of knowledge. We examined category naming on two tasks (picture naming and naming-to-description) in patients with Alzheimer's disease (AD: n 5 11), Lewy body dementia (DLB: n 5 11) and healthy elderly matched controls (n 5 22). The DLB and AD groups showed significantly worse naming on both tasks, although the AD patients were more impaired than the DLB patients. Like some AD patients, some DLB patients showed evidence of category-specific naming deficits, and strikingly, all 25 significant category dissociations were for living things. The latter finding accords with the preponderance of living deficits previously documented for AD patients, but extends this finding to DLB patients. The implications of this category bias is discussed in relation to relevant models of category specificity. (JINS, 2007, 13, 401-409.)

Language deterioration in bilingual Alzheimer's disease patients: A longitudinal study

“…In picture naming, the AD patients made more errors in natural/living items in all assessment times for semantic errors and also for crosslanguage intrusions at follow-up, replicating one of the most frequent category-specific deficits in AD (e.g., Chertkow, Whatmough, Saumier, & Duong. 2008;Laws, Crawford, Gnoato, & Sartori, 2007;Tippett, Meier, Blackwood, & Diaz-Asper, 2007;Zannino, Perri, Carlesimo, Pasqualetti, & Caltagirone, 2002). However, this effect was less consistent in translation, suggesting that the semantic properties of the words are task sensitive.…”

Interhemispheric Differences in Knowledge of Animals Among Patients With Semantic Dementia

“…41–43 Investigators have described patients with herpes simplex encephalitis and bilateral inferior temporal lobe damage who have had significantly greater difficulty in recognizing and naming animals and food items than with inanimate objects. 44–49 Differential impairment for living things has also occurred among head-injury patients and in SD.…”

In the Absence of Animacy: Superordinate Category Structure Affects Subordinate Label Verification

“…This dissociation of impairment has been taken as evidence that different superordinate categories are processed in neuroanatomically distinct cortical regions. However, selective deficits have also been observed in patients with less focused neural damage (e.g., Alzheimers: [11], [12]), raising the possibility that selective deficits can arise from unfocussed damage to a more distributed system. Furthermore, while neuroimaging studies have identified regions of activation specific to animates or inanimates [13], [14], these categories also activate common regions, with only small and inconsistent differences between domains [15].…”