Using remote, digital, multi-day testing to characterize long-term forgetting in cognitively unimpaired older adults.

Introduction: Accelerated long-term forgetting (LTF) might be an early marker of subtle memory changes in older adults at risk for Alzheimer's disease (AD). We leveraged remote, multi-day digital testing to characterize LTF in older adults and investigated its association with initial learning and AD imaging biomarkers.

Methods: One hundred four cognitively unimpaired older adults completed a face-name memory task for seven consecutive days and were asked to recognize face-name pairs 1 week later. LTF was computed as the number of correctly identified stimuli divided by a participant's maximum performance during learning.

Results: Better learning was associated with less LTF (β = 0.52, 95% confidence interval [CI]:0.34-0.71, p < 0.001). Accelerated LTF was associated with cortical thinning in AD-signature regions (β = 0.33, 95% CI: 0.13-0.52, p = 0.001), but associations with regional tau were more subtle.

Discussion: Remote, multi-day testing may facilitate the assessment of LTF as an early cognitive marker of preclinical AD, but further replication is needed.

Highlights: Using digital, remote assessments, we evaluated long-term forgetting in cognitively unimpaired older adults. We found a potential association between long-term forgetting and tau in Alzheimer's disease (AD)-related regions. Assessing long-term forgetting may facilitate early detection of AD-related cognitive decline.