Related Experiment Video
Updated: Aug 14, 2026

Lexical Decision Task for Studying Written Word Recognition in Adults with and without Dementia or Mild Cognitive Impairment
Published on: June 25, 2019
Category and letter fluency in semantic dementia, primary progressive aphasia, and Alzheimer's disease
Cecile A Marczinski1, Andrew Kertesz
1Department of Cognitive Neurology, St. Joseph's Hospital, University of Western Ontario, London, Ont., Canada. camarc2@uky.edu
Abstract:
This study examined the impact of various degenerative dementias on access to semantic knowledge and the status of semantic representations. Patients with semantic dementia, primary progressive aphasia, and Alzheimer's disease were compared with elderly controls on tasks of category and letter fluency, with number of words generated, mean lexical frequency and errors recorded. The findings are consistent with the view that category and letter fluency rely on both common and unique cognitive processes. Fluency tasks, with the richness of data obtained, are valuable in distinguishing different dementia syndromes from one another.
Related Concept Videos
Alzheimer Disease l: Introduction
Dementia l: Introduction
Alzheimer Disease ll: Pathophysiology
Dementia
The progression of dementia is generally gradual.
Alzheimer's Disease: Overview
The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau...
Language and Cognition
