Learning trajectories in the preclinical phase of Alzheimer's disease over two years measured using digital remote memory assessments

• Applicant: Dr. Iris Blotenberg
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology ; Personality Psychology, Clinical and Medical Psychology, Methodology ; Public Health, Healthcare Research, Social and Occupational Medicine
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 557339238

The preclinical phase of Alzheimer's disease is the most promising time window for interventions to slow the progression of the disease. However, it is a significant challenge for the field to measure the subtle cognitive changes in this early phase. One cognitive process that is affected particularly early in Alzheimer's disease is memory consolidation. The Boston Remote Assessment for NeuroCognitive Health (BRANCH) was developed to detect subtle changes in memory consolidation during the preclinical phase of Alzheimer's disease. BRANCH is a web-based platform that enables the remote administration of memory tests and measures learning effects in these tests over several days. Initial studies have shown that individuals with elevated Alzheimer's disease biomarkers exhibit reduced learning effects in BRANCH compared to individuals with non-elevated Alzheimer’s disease biomarkers. So far, little is known about how memory consolidation changes over time in the preclinical phase of Alzheimer's disease. The aim of this project is to investigate how learning effects differ over a period of two years in individuals with elevated Alzheimer's disease biomarkers compared to individuals without elevated levels. This project uses data from three ongoing cohort studies (Harvard Aging Brain Study, Instrumental Activities of Daily Living Study, Subjective Cognitive Decline Study). Cognitively unimpaired older adults with known biomarker status completed multi-day memory tasks from BRANCH regularly over two years. The first multiday testing period was completed by n = 232 individuals, in the second testing period six months later, n = 164 individuals participated. Data collection for subsequent testing periods is still ongoing. For each multi-day testing period, a learning score is calculated that summarizes the learning effects. The "Area under the Curve" is calculated for this purpose, a score that summarizes both the rapidity with which an individual learns and the total accumulation of memory content. Changes in the learning score in the memory tasks over two years will be analyzed using multilevel growth curve models. These flexible models allow for the modelling of individual learning trajectories and the examination of the role of Alzheimer's disease biomarkers and sociodemographic variables for changes in learning effects over time. This research project is significant for neuropsychological and intervention research: Examining the cognitive trajectories provides information on when digital tests are particularly sensitive to detecting changes in the preclinical phase of Alzheimer's disease. A better understanding of the progression of cognitive changes in the preclinical phase of Alzheimer's disease is also important for better understanding the progression of the disease and for being able to detect intervention effects in the future.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Professorin Rebecca Amariglio, Ph.D.