Using objective and subjective measures of mind wandering to predict progression to development of cognitive impairment and test associations with Alzheimer disease biomarkers

Introduction: Mind wandering decreases in healthy aging, and in some cases, it is further reduced in Alzheimer disease (AD). However, little is known about how mind wandering changes during the preclinical phase of AD, which is a critical period for intervention. The present study aims to provide novel evidence for the utility of objective and subjective measures of mind wandering in evaluating the risk of developing cognitive impairment and their association with AD biomarkers. Methods: Participants (N = 504; M_age = 69.54 years, SD_age = 8.95 years) completed a Sustained Attention to Response Task (SART). We calculated objective (reaction time coefficient of variation; RT CoV) and subjective (self-reported frequency of off-task thoughts) mind wandering measures during the SART for participants who remained cognitively stable (N = 349) and those who eventually developed cognitive impairment (progressors; N = 155). A subset of participants (N = 211) completed the SART annually and had recent CSF biomarkers. Results: Objective and subjective mind wandering significantly differed between progressors and cognitively stable participants at baseline and predicted likelihoods of progression. Moreover, baseline subjective mind wandering predicted progression beyond standard neuropsychological measures. Longitudinal models indicated that biomarker negative, but not positive, participants showed a significant reduction in RT CoV over time, possibly reflecting practice-related changes in performance. There were no longitudinal associations with subjective mind wandering. Conclusions: Mind wandering is a common activity and may reflect a healthy cognitive system in older age. Subjective measures of mind wandering may be useful in predicting the later onset of cognitive impairment, while objective measures may be more sensitive to longitudinal changes.