Event-based prospective memory and everyday forgetting in healthy older adults and individuals with mild cognitive impairment

An event-based nonfocal task was used to evaluate prospective memory (PM) and the relationship between PM, neuropsychological testing data, and everyday forgetting. Twenty-four participants with mild cognitive impairment (MCI) and 24 age- and education-matched cognitively healthy adults responded to a nonfocal PM cue, while completing an ongoing working memory task. Neuropsychological testing data and self- and informant-report of frequency of forgetting were also gathered. Compared to healthy adults, the MCI participants exhibited significantly poorer prospective remembering and ongoing task performance, despite similar self-reported effort directed to the PM task. Both self- and informant-report indicated that the MCI group was experiencing a higher frequency of everyday forgetting than the healthy adult group. Self-report of everyday forgetting was correlated with PM task performance for the healthy adults, but not for the MCI participants. For the healthy adults, correlational analyses also showed significant relationships between PM accuracy and tests of memory and executive functioning, suggesting that both spontaneous retrieval processes and effortful, strategic monitoring may be important in supporting prospective remembering for this nonfocal PM task. The stronger relationships between PM accuracy and memory and language tests for the MCI group suggest that their poorer event-based prospective remembering might be linked to impaired spontaneous retrieval processes, which are thought to be supported by medial temporal structures.