Abstract
Introduction: In cognitively normal (CN) adults, increased rates of amyloid beta (Aβ) accumulation can be detected in low Aβ (Aβ–) apolipoprotein E (APOE) ε4 carriers. We aimed to determine the effect of ε4 on the ability to benefit from experience (ie, learn) in Aβ–CNs. Methods: Aβ– CNs(n= 333) underwent episodic memory assessments every 18 months for 108 months. A subset (n = 48) completed the Online Repeatable Cognitive Assessment-Language Learning Test (ORCA-LLT) over 6 days. Results: Aβ– ε4 carriers showed significantly lower rates of improvement on episodic memory over 108 months compared to non-carriers (d = 0.3). Rates of learning on the ORCA-LLT were significantly slower in Aβ– ε4 carriers compared to non-carriers (d = 1.2). Discussion: In Aβ– CNs,ε4 is associated with a reduced ability to benefit from experience. This manifested as reduced practice effects (small to moderate in magnitude) over 108 months on the episodic memory composite, and a learning deficit (large in magnitude) over 6 days on the ORCA-LLT. Alzheimer’s disease (AD)–related cognitive abnormalities can manifest before preclinical AD thresholds.
RAS ID
39576
Document Type
Journal Article
Date of Publication
2021
Volume
13
Issue
1
Funding Information
Edith Cowan University National Health and Medical Research Council Funding information : https://doi.org/10.1002/dad2.12136
School
School of Medical and Health Sciences / Centre of Excellence for Alzheimer's Disease Research and Care
Grant Number
NHMRC Number : GNT1111603, GNT1147465
Grant Link
http://purl.org/au-research/grants/nhmrc/GNT1111603 http://purl.org/au-research/grants/nhmrc/GNT1147465
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Publisher
Wiley
Comments
Lim, Y. Y., Baker, J. E., Mills, A., Bruns Jr, L., Fowler, C., Fripp, J., ... Maruff, P. (2021). Learning deficit in cognitively normal APOE ε4 carriers with LOW β‐amyloid. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring, 13(1), article e12136. https://doi.org/10.1002/dad2.12136