Background: Pause duration analysis is a common feature in the study of discourse in Alzheimer's disease (AD) and may also be helpful for its early detection. However, studies involving patients with amnestic mild cognitive impairment (aMCI) have yielded varying results. Objectives: To characterize the probability density distribution of speech pause durations in AD, two multi-domain amnestic MCI patients (with memory encoding deficits, a-mdMCI-E, and with retrieval impairment only, a-mdMCI-R) and healthy controls (HC) in order check whether there are significant differences between them. Method: 112 picture-based oral narratives were manually transcribed and annotated for the automatic extraction and analysis of pause durations. Different probability distributions were tested for the fitting of pause durations while truncating shorter ranges. Recent findings in the field of Statistics were considered in order to avoid the inherent methodological uncertainty that this type of analysis entails. Results: A lognormal distribution (LND) explained the distribution of pause duration for all groups. Its fitted parameters (mu, sigma) followed a gradation from the group with shorter durations and a higher tendency to produce short pauses (HC) to the group with longer pause durations and a considerably higher tendency to produce long pauses with greater variance (AD). Importantly, a-mdMCI-E produced significantly longer pauses and with greater variability than their a-mdMCI-R counterparts (alpha = 0.05). Conclusion: We report significant differences at the group level in pause distribution across all groups of study that could be used in future diagnostic tools and discuss the clinical implications of these findings, particularly regarding the characterization of aMCI.

中文翻译：

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语音暂停分布是阿尔茨海默氏病的早期标志

背景：停顿持续时间分析是阿尔茨海默病（AD）话语研究中的常见特征，也可能有助于早期发现。但是，涉及遗忘性轻度认知障碍（aMCI）患者的研究得出了不同的结果。目的：为了表征AD，两名多域记忆删除MCI患者（记忆编码缺陷，a-mdMCI-E和仅具有检索障碍的a-mdMCI-R）和健康对照组（AD）中语音暂停持续时间的概率密度分布HC），以检查它们之间是否存在显着差异。方法：对112张基于图片的口头叙述进行手动转录和注释，以自动提取和分析暂停时间。测试了不同的概率分布，以适应暂停持续时间，同时缩短较短的范围。考虑了统计领域的最新发现，以避免这种类型的分析所固有的方法学不确定性。结果：对数正态分布（LND）解释了所有组的停顿持续时间的分布。它的拟合参数（mu，sigma）遵循从持续时间较短和产生短暂停顿（HC）趋势较高的组到逐渐停顿持续时间较长且产生较长停顿并具有较大方差（AD）趋势的组的等级。重要的是，与a-mdMCI-R对应物相比，a-mdMCI-E产生的停顿时间明显更长，并且变异性更大（alpha = 0.05）。结论：