Due to advances in the early detection of Alzheimer's disease (AD) biomarkers including beta-amyloid (Aβ), neuropsychological measures that are sensitive to concurrent, subtle changes in cognition are critically needed. Story recall tasks have shown sensitivity to early memory declines in persons with mild cognitive impairment (MCI) and early stage dementia, as well as in persons with autosomal dominantly inherited AD up to 10 years prior to a dementia diagnosis. However, the evidence is inconclusive regarding relationships between evidence of Aβ and story recall measures. Because story recall tasks require the encoding and delayed retrieval of several lexical-semantic categories, such as proper names, verbs, and numerical expressions, and because lexical categories have been shown to be differentially impaired in persons with MCI, we focused on item-level analyses of lexical-semantic retrieval from a quintessential story recall task, Logical Memory from the Wechsler Memory Scale-Revised. Our objective was to investigate whether delayed recall of lexical categories (proper names, verbs and/or numerical expressions), as well as the traditional total score measure, was associated with “preclinical AD,” or cognitively unimpaired adults with positive Aβ deposition on positron emission tomography (PET) neuroimaging using Pittsburgh Compound B (PiB). We developed an item-level scoring system, in which we parsed items into lexical categories and examined the immediate and delayed recall of these lexical categories from 217 cognitively unimpaired participants from the Wisconsin Registry for Alzheimer's Prevention (WRAP). We performed binary logistic regression models with story recall score as predictor and Aβ status (positive/negative) as the outcome. Using baseline Logical Memory data, proper names from delayed story recall were significantly associated with Aβ status, such that participants who recalled more proper names were less likely to be classified as PiB(+) (odds ratio = .58, p = .01). None of the other story recall variables, including total score, were associated with PiB status. Secondary analyses determined that immediate recall of proper names was not significantly associated with Aβ, suggesting a retrieval deficit rather than that of encoding. The present findings suggest that lexical semantic retrieval measures from existing story recall tasks may be sensitive to Aβ deposition, and may provide added utility to a widely-used, long-standing neuropsychological test for early detection of cognitive decline on the AD continuum.

由于阿尔茨海默病 (AD) 生物标志物（包括 β-淀粉样蛋白 (Aβ)）的早期检测取得了进展，因此迫切需要对认知中同时出现的微妙变化敏感的神经心理学测量方法。故事回忆任务显示，轻度认知障碍 (MCI) 和早期痴呆症患者以及常染色体显性遗传 AD 患者在痴呆症诊断前 10 年内，其早期记忆力下降很敏感。然而，关于 Aβ 证据与故事回忆测量之间的关系，证据尚无定论。由于故事回忆任务需要对多个词汇语义类别（例如专有名称、动词和数字表达）进行编码和延迟检索，并且由于词汇类别已被证明在 MCI 患者中存在不同程度的受损，因此我们专注于项目级别从典型的故事回忆任务中进行词汇语义检索分析，来自韦克斯勒记忆量表修订版的逻辑记忆。我们的目的是调查词汇类别（专有名词、动词和/或数字表达）的延迟回忆以及传统的总分测量是否与“临床前 AD”或正电子 Aβ 沉积呈阳性的认知未受损的成年人相关使用匹兹堡化合物 B (PiB) 进行发射断层扫描 (PET) 神经成像。我们开发了一个项目级评分系统，将项目解析为词汇类别，并检查来自威斯康星州阿尔茨海默病预防登记处 (WRAP) 的 217 名认知未受损的参与者对这些词汇类别的即时和延迟回忆。我们执行二元逻辑回归模型，以故事回忆分数作为预测因子，以 Aβ 状态（阳性/阴性）作为结果。 使用基线逻辑记忆数据，延迟故事回忆的专有名称与 Aβ 状态显着相关，因此回忆起更多专有名称的参与者不太可能被归类为 PiB(+)（比值比 = .58， p = .01） 。其他故事回忆变量（包括总分）均与 PiB 状态无关。二次分析确定，正确名称的立即回忆与 Aβ 没有显着相关，这表明检索缺陷而不是编码缺陷。目前的研究结果表明，现有故事回忆任务中的词汇语义检索措施可能对 Aβ 沉积敏感，并且可能为广泛使用的长期神经心理学测试提供额外的实用性，以早期检测 AD 连续体的认知衰退。