Prospective memory in Alzheimer-type dementia: Exploring prospective memory performance in an age-stratified sample

Abstract

Prospective memory (PM), the memory for future intentions, is an essential component of many day-to-day activities. PM accuracy has consistently been found to decline as a function of age and is further impaired in Alzheimer’s disease (AD). In the present study, subjective PM failures, PM accuracy, and cost of carrying a PM were recorded in 42 healthy elderly, 34 younger old, and 45 older old AD participants. It was found that PM deficits across the AD cohort did not change as a function of age. In addition, while PM accuracy was impaired compared to age-matched controls, cost of carrying a PM intention did not differ across the three groups. Evidence that AD participants show a reaction time (RT) cost of PM intention alongside an impaired PM accuracy indicates that the PM intention is held, but is not implemented effectively. The fact that the cost is independent of age and dementia suggests that it may not index working memory (WM) resource. At a practical level, the study suggests that for a comprehensive evaluation of PM competence cost of carrying a PM intention should be measured alongside PM accuracy.

• Alzheimer’s disease
• Prospective memory
• Age-dependent change
• Severity
• Cognition

We would like to give a special thank you to every one of the volunteers, and the research staff at Cognitive Treatment and Research Unit (CTRU), who contributed to this research.

This work was financially supported by the Economic and Social Research Council [grant number ES/102803X/1]; Sussex Partnership NHS Foundation Trust.