In the absence of a pharmacological cure, finding the most sensitive early cognitive markers of Alzheimer's disease (AD) is becoming increasingly important. In this article we review evidence showing that brain mechanisms of spontaneous, but stimulus-dependent, cognition overlap with key hubs of the default mode network (DMN) that become compromised by amyloid pathology years before the clinical symptoms of AD. This leads to the formulation of a novel hypothesis which predicts that spontaneous, but stimulus-dependent, conscious retrieval processes, that are generally intact in healthy aging, will be particularly compromised in people at the earliest stages of AD. Initial evidence for this hypothesis is presented across diverse experimental paradigms (e.g., prospective memory, mind-wandering), and new avenues for research in this area are outlined.

中文翻译：

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自发认知缺陷是阿尔茨海默病的早期标志

在缺乏药物治疗的情况下，寻找阿尔茨海默病 (AD) 最敏感的早期认知标志物变得越来越重要。在本文中，我们回顾了证据，表明自发但依赖于刺激的认知大脑机制与默认模式网络 (DMN) 的关键枢纽重叠，而默认模式网络 (DMN) 的关键枢纽在 AD 临床症状出现前数年就受到淀粉样蛋白病理学的影响。这导致了一个新假设的形成，该假设预测自发的、但依赖于刺激的、有意识的检索过程，在健康老龄化中通常完好无损，在 AD 的早期阶段将特别受到损害。这一假设的初步证据是通过不同的实验范式（例如，前瞻记忆、走神）提出的，