摘要：A major risk factor for late-onset Alzheimer’s type dementia (DAT) is the carriage of theε4 allele of the apolipoprotein E (ApoE) gene. Identifying cognitive deficits in healthyApoE-ε4 carriers is valuable in order to develop interventions to prevent them fromdeveloping DAT. Existing evidence about cognitive deficits in the domains of episodicmemory and cognitive control specific to ApoE-ε4 is contradictory.The objective of our research was to assess episodic memory and cognitive controlin healthy ApoE-ε4 carriers.Cognitively healthy ApoE-ε4 carriers (13 ε4/ε4 heterozygotes) and noncarriers (22ε3/ε3 homozygotes), who were matched on age and family history of DAT, were comparedon episodic-memory and cognitive-control tasks. Episodic-memory tasks wereverbal and visual recognition tasks with a systematic variation of distractor-to-targetsimilarity. Executive functions were assessed by a task for updating working memory, aninhibition task, and a switching task. Working-memory capacity was also assessed.The results showed that executive functions were generally not impaired in the carriers,but carriers showed a specific increase in accuracy-related switch costs. Workingmemorycapacity was not reduced in the carriers. In the domain of episodic memory, thecarriers were found to make more errors with phonetic distractors in the verbal episodicmemorytask. They also tended to make more errors with visually dissimilar distractorsin the visual episodic-memory task.
