Naturalistic assessment of task interruption in individuals with mild cognitive impairment.

Objective: Interruptions are ubiquitous in everyday life, and recovering from interruptions requires several cognitive processes working in tandem. In this study, we assessed the effects of an interruption on the performance of older individuals with and without mild cognitive impairment (MCI) completing everyday tasks in a naturalistic apartment setting. Method: Thirty-two persons with MCI and 64 cognitively healthy older adults (HOA) completed two different sets of everyday activities, of which one received an interruption. Participants also completed tests assessing cognitive constructs thought to be important in interruption recovery including retrospective memory, prospective memory, planning, working memory, and executive function. Results: As a consequence of an interruption, participants with MCI took longer to complete primary task demands and made more substitution errors, but did not make more omission errors. In contrast, an interruption led HOAs to make more omission errors, but their time on task was not affected. Results from a hierarchical linear regression suggest that the ecologically valid interruption task time was more predictive of everyday functional status than the traditional neuropsychological measures. Conclusions: Results suggest that a brief task interruption taxed cognitive resources of both MCI and HOA groups, but was more detrimental to MCI in terms of time on task and total errors committed. Participant groups appeared to use a speed—accuracy trade-off to mitigate negative effects, where HOAs emphasized speed and MCI participants focused on accuracy. Amount of cognitive engagement/disengagement was also theorized to have played a role, where MCI may have maintained information online throughout the interruption, and HOAs disengaged and reengaged resulting in worse reactivation of goals. Although MCI held onto task goals, their execution of details was imperfect over the interruption delay resulting in substitution errors likely due to further taxed executive abilities. (PsycINFO Database Record (c) 2019 APA, all rights reserved)