Capturing cognitive capacity in the everyday environment across a continuum of cognitive decline using a smartwatch n-back task and ecological momentary assessment.

OBJECTIVE

Cognitive testing using mobile technologies can assist with early detection of cognitive decline. We use ecological momentary assessment to investigate the feasibility, reliability, and validity of a smartwatch n-back task (1-back) delivered to adults across the cognitive continuum.

METHOD

One hundred seventy-four community-dwelling individuals ( = 70.51) representing healthy older adults, individuals with subjective cognitive decline, and mild cognitive impairment completed a neurocognitive assessment battery and wore a smartwatch for 7+ days. Participants were prompted 4 times per day to complete an n-back task on the smartwatch.

RESULTS

Across all groups, findings indicated an acceptable task adherence rate (> 78%; = 174) and response rate (> 89%; = 158 -back analysis sample). Supporting external validity, participants with mild cognitive impairment were less accurate, had fewer total correct responses, and performed at lower initial levels than both healthy older adults and subjective cognitive decline, ω²s > .09. Intraindividual variability was greater for the mild cognitive impairment group compared to healthy older adults, but subjective cognitive decline did not differ significantly from either group, ω² = .12. For discriminant and convergent validity, -back total correct correlated with performance on standardized assessments of executive attention, whereas intraindividual variability correlated with real-world factors (i.e., context, everyday function). Reliability assessment revealed stability for -back measures after four to six posttraining trials and excellent test-retest reliability for total correct after 5 months. Finally, combining -back and clinical measures improved classification accuracy.

CONCLUSIONS

Findings suggest the smartwatch -back task is feasible for collecting cognitive data across the cognitive continuum with demonstrated reliability and validity in the everyday environment using ecological momentary assessment. (PsycInfo Database Record (c) 2025 APA, all rights reserved).