Loss of person-specific knowledge in Alzheimer’s disease: Evidence from priming

Abstract

Semantic deficits in Alzheimer’s disease (AD) are often more severe for items that are characterized by a unique semantic and lexical association, such as famous people. Whether these deficits are due to the degradation of semantic information or a deficit in the ability to intentionally access semantic knowledge remains controversial. To assess the integrity of the semantic system without explicitly accessing it, a priming paradigm was used. Semantic and repetition priming effects in individuals with AD (n = 7) and age-matched controls (n = 13) were measured in a familiarity judgment task using visually-presented names of famous people. A defective priming effect in AD subjects was observed in the semantic priming but not in the repetition priming condition. Therefore, the semantic impairments observed in AD may indicate a degraded representation of the semantic information concerning famous people.

Keywords:

• Aging
• Cognition
• Dementia
• Executive function
• Famous people
• Neuropsychological tests

This research was supported by the Fondation Institut de gériatrie de Montréal, Réseau Québecois de Recherche sur le Vieillissement, and Fonds de recherche du Québec—Santé. We thank Valérie Dostie for carrying out the neuropsychological assessment. The authors have no conflicts of interest to disclose.