Lim Yen Ying, Baker Jenalle E, Mills Andrea, Bruns Loren, Fowler Christopher, Fripp Jurgen, Rainey-Smith Stephanie R, Ames David, Masters Colin L, Maruff Paul
Turner Institute for Brain and Mental Health, School of Psychological Sciences Monash University Clayton Victoria Australia.
The Florey Institute of Neuroscience and Mental Health University of Melbourne Parkville Victoria Australia.
Alzheimers Dement (Amst). 2021 Mar 16;13(1):e12136. doi: 10.1002/dad2.12136. eCollection 2021.
In cognitively normal (CN) adults, increased rates of amyloid beta (Aβ) accumulation can be detected in low Aβ (Aβ-) apolipoprotein E () ε4 carriers. We aimed to determine the effect of ε4 on the ability to benefit from experience (ie, learn) in Aβ- CNs.
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.
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).
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.
在认知正常（CN）的成年人中，低淀粉样β蛋白（Aβ）（Aβ-）载脂蛋白E（）ε4携带者体内可检测到Aβ积累率增加。我们旨在确定ε4对Aβ-CN个体从经验中获益（即学习）能力的影响。
333名Aβ-CN个体每18个月接受一次情景记忆评估，为期108个月。其中一个亚组（n = 48）在6天内完成了在线可重复认知评估-语言学习测试（ORCA-LLT）。
与非携带者相比，Aβ-ε4携带者在108个月内情景记忆改善率显著更低（d = 0.3）。与非携带者相比，Aβ-ε4携带者在ORCA-LLT上的学习速度显著更慢（d = 1.2）。
在Aβ-CN个体中，ε4与从经验中获益的能力降低有关。这表现为在108个月内情景记忆综合指标上练习效果降低（幅度小到中等），以及在ORCA-LLT上6天内存在学习缺陷（幅度大）。阿尔茨海默病（AD）相关的认知异常可在临床前AD阈值之前出现。
