Objectives: By use of purer indices of PM and RM components than previous studies and adoption of three PM task types, the present study aimed to investigate the deficits of these two components underlying global impairment at a PM task in individuals with amnestic mild cognitive impairment (aMCI).
Methods: Nineteen aMCI patients and 22 normal controls were examined on event-, time- and activity-based PM tasks. Separate scores were obtained for initiation of intentions (i.e. PM component) and for the content of the intentions (i.e. RM component).
Results: Individuals with aMCI achieved lower PM component (but not RM component) scores than NCs across all three PM tasks. Furthermore, there was a trend for greater impairment on activity-based than time-based and event-based PM tasks, but which did not reach significance. In addition, a significant association between PM component and an executive function test was observed in aMCI group. PM task performance, especially activity-based PM task performance and PM component performance, successfully discriminated between aMCI and NC and was able to do so above and beyond the executive function tests.
Conclusions: Our finding suggested that the deficits in PM component, related to a disrupted executive control processes, were responsible for the impaired ability of individuals with aMCI to realize delayed intentions.