The spectrum of category effects in object and action knowledge in dementia of the Alzheimer's type.

Fung, Torrance; Chertkow, Howard; Murtha, Susan; Whatmough, Christine; Péloquin, Laurence; Whitehead, Victor; Templeman, F. David

doi:10.1037/0894-4105.15.3.371

Cited by 52 publications

(41 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Semantic deficits have been documented in AD using a variety of standard clinical neuropsychological tests (Huff et al, 1986;Rosser and Hodges, 1994;Hodges and Patterson, 1995;Adlam et al, 2006) and using more specific measures (Chertkow and Bub, 1990;Hodges et al, 1992;Greene and Hodges, 1996;Fung et al, 2001;Thompson et al, 2002;Whatmough et al, 2003;Joubert et al, 2010). Working memory deficits are also frequently reported in AD and involve reduced span for words, digits, letters and spatial locations (Grossi et al, 1993;Belleville et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Early-onset and late-onset Alzheimer's disease are associated with distinct patterns of memory impairment

Joubert

Gour

Guedj

et al. 2016

Cortex

View full text Add to dashboard Cite

The goal of this study was to investigate the specific patterns of memory breakdown in patients suffering from early-onset Alzheimer's disease (EOAD) and late-onset Alzheimer's disease (LOAD). Twenty EOAD patients, twenty LOAD patients, twenty matched younger controls, and twenty matched older controls participated in this study.All participants underwent a detailed neuropsychological assessment, an MRI scan, an FDG-PET scan, and AD patients had biomarkers as supporting evidence of both amyloïdopathy and neuronal injury. Results of the neuropsychological assessment showed that both EOAD and LOAD groups were impaired in the domains of memory, executive functions, language, praxis, and visuoconstructional abilities, when compared to their respective control groups. EOAD and LOAD groups, however, showed distinct patterns of memory impairment. Even though both groups were similarly affected on measures of episodic, short term and working memory, in contrast semantic memory was significantly more impaired in LOAD than in EOAD patients. The EOAD group was not more affected than the LOAD group in any memory domain. EOAD patients, however, showed significantly poorer performance in other cognitive domains including executive functions and visuoconstructional abilities. A more detailed analysis of the pattern of semantic memory performance among patient groups revealed that the LOAD was more profoundly impaired, in tasks of both spontaneous recall and semantic recognition.Voxel-Based Morphometry (VBM) analyses showed that impaired semantic performance in patients was associated with reduced gray matter volume in the anterior temporal lobe region, while PET-FDG analyses revealed that poorer semantic performance was associated with greater hypometabolism in the left temporoparietal region, both areas reflecting key regions of the semantic network. Results of this study indicate that EOAD and LOAD patients present with distinct patterns of memory impairment, and that a genuine semantic impairment may represent one of the clinical hallmarks of LOAD.

show abstract

Section: Introductionmentioning

confidence: 99%

Early-onset and late-onset Alzheimer's disease are associated with distinct patterns of memory impairment

Joubert

Gour

Guedj

et al. 2016

Cortex

View full text Add to dashboard Cite

show abstract

“…Some work demonstrates that verb meaning is particularly impaired in AD White-Devine et al, 1996;Yi et al, 2006), although others report less impairment for verbs (Fung et al, 2001;Robinson et al, 1999). Several factors may contribute to AD patients' difficulty learning the meaning of a new verb.…”

Section: Difficulty Acquiring the Meaning Of A New Word In Admentioning

confidence: 99%

“…This includes visual confrontation naming difficulty with verbs (Robinson, Grossman, White-Devine, & D'Esposito, 1996), a deficit with verb-picture matching , and an impairment selecting the best of four verbs related to a description or a video (Yi, Moore, & Grossman, 2006). Although there are occasional exceptions to this relative difficulty with verbs in AD (Fung et al, 2001;Robinson, Rossor, & Cipolotti, 1999), a number of accounts have been forwarded to explain their verb deficit. These focus on the several important ways that verbs differ from nouns.…”

Section: Introductionmentioning

confidence: 99%

Verb acquisition and representation in Alzheimer's disease

et al. 2007

View full text Add to dashboard Cite

We examined the implicit acquisition and mental representation of a novel verb in patients with probable Alzheimer's disease (AD). Patients were exposed to the new verb in a naturalistic manner as part of a simple picture story. We probed grammatical, semantic and thematic matrix knowledge of the verb soon after presentation and again one week later. We found partial verb acquisition that was retained over one week. AD patients did not differ from controls in their acquisition and retention of a new verb's major grammatical subcategory, although they acquired little of its semantic properties and displayed minimal acquisition of the new word's thematic matrix. Moreover, AD patients appeared to maintain their acquired grammatical knowledge over one week. We discuss the implications of these findings from several perspectives, including the modularity of the language processing system, the relationship between episodic memory and semantic memory, and the role of the preserved implicit memory system in AD patients' partially successful lexical acquisition.

show abstract

“…These control ceiling effects probably reflect the widespread reliance upon simple line drawn stimuli that controls have little difficulty in naming under normal conditions (the Snodgrass and Vanderwart corpus is used in 90+% of category specific studies: Laws and Gale 2002a,b). Studies comparing patient performance with that of ceiling level performance in controls will distort the findings for patients (including both the degree and possibly the types of deficit reported: see Laws et al, 2002Laws et al, , 2003Fung et al 2001).…”

Section: Introductionmentioning

confidence: 99%

When is Category Specific in Alzheimer's Disease?

Laws

Gale

Leeson

et al. 2005

Cortex

View full text Add to dashboard Cite

Mixed findings have emerged concerning whether category-specific disorders occur in Alzheimer's disease. Factors that may contribute to these inconsistencies include: ceiling effects / skewed distributions for control data in some studies; differences in the severity of cognitive deficit in patients; and differences in the type of analysis (in particular, if and how controls are used to analyse single case data).We examined picture naming in Alzheimer's patients and matched elderly healthy normal controls in three experiments. These experiments used stimuli that did and did not produce ceiling effects / skewed data in controls. In Experiment 1, we examined for category effects in individual DAT patients using commonly used analyses for single cases (χ 2 and z-scores). The different techniques produced quite different outcomes. In Experiment 2a, we used the same techniques on a different group of patients with similar outcomes. Finally, in Experiment 2b, we examined the same patients but (a) used stimuli that did not produce ceiling effects / skewed distributions in healthy controls, and (b) used statistical methods that did not treat the control sample as a population. We found that ceiling effects in controls may markedly inflate the incidence of dissociations in which living things are differentially impaired and seriously underestimate dissociations in the opposite direction. In addition, methods that treat the control sample as a population led to inflation in the overall number of dissociations detected. These findings have implications for the reliability of category effects previously reported both in Alzheimer patients and in other pathologies. In particular, they suggest that the greater proportion of living than nonliving deficits reported in the literature may be an artifact of the methods used.

show abstract

The spectrum of category effects in object and action knowledge in dementia of the Alzheimer's type.

Cited by 52 publications

References 43 publications

Early-onset and late-onset Alzheimer's disease are associated with distinct patterns of memory impairment

Early-onset and late-onset Alzheimer's disease are associated with distinct patterns of memory impairment

Verb acquisition and representation in Alzheimer's disease

When is Category Specific in Alzheimer's Disease?

Contact Info

Product

Resources

About