Introduction

This study investigated how Alzheimer’s Disease (AD) affects numerosity estimation abilities (e.g., finding the approximate number of items in a collection).

Method

Across two experiments, performance from HOA (i.e., Healthy Older Adults; N = 48) and AD patients (N = 50) was compared on dot comparison tasks. Participants were presented with two dot arrays and had to select the more numerous dot array in comparison tasks. They also took a Simon task and a number-line tasks (i.e., number-line tasks in which they had to indicate the position of a number on a line 0 to 100 or on a line 0 to 1,000 in the number-line task).

Results

In Experiment 1, (a) AD patients obtained significantly poorer performance while comparing collections of dots, especially harder (small-ratio) collections, (b) these deficits correlated with poorer performance on the number-line task for larger numerosities (i.e., 0 to 1,000), and (c) AD patients showed poorer performance on incongruent (where numerosity and area occupied by dots mismatched) than on congruent items (where both features matched), while HOA showed no congruency effects. Experiment 2 showed (a) congruency effects in both groups when convex hull was tested as an incongruent feature, and (b) comparable sequential modulations of congruency effects in both groups.

Conclusions

Our findings showed that numerosity abilities decline in AD patients, and that this decline results from impaired domain-specific processes (i.e., numerosity processing) and domain-general processes (i.e., inhibition). These findings have important implications to further our understanding of how specific and general cognitive processes contribute to numerosity estimation/comparison performance, and how such contributions change during Alzheimer’s disease.

中文翻译：

---

阿尔茨海默氏病会破坏数字估计中的特定领域和一般领域的过程。

介绍

这项研究调查了阿尔茨海默氏病（AD）如何影响数字估计能力（例如，找到集合中的大概项目数）。

方法

在两个实验中，在点比较任务中比较了HOA（即健康的老年人；N  = 48）和AD患者（N  = 50）的表现。向参与者展示了两个点阵列，并且在比较任务中必须选择更多的点阵列。他们还接受了Simon任务和数字行任务（即，数字行任务，其中他们必须在数字行任务中的0到100行或0到1,000行中指示数字的位置） 。

结果

在实验1中，（a）AD患者在比较点集合，尤其是较硬（小比例）集合时获得了明显较差的性能，（b）这些缺陷与数字量较大（例如0的数字行任务）上的较差性能相关。到1,000），以及（c）AD患者在不一致的情况下（数字和点所占的面积不匹配）表现不如在一致的项目（两个特征都匹配）上的表现差，而HOA没有一致性表现。实验2显示了（a）当测试凸包作为不一致特征时，两组的一致性效果，以及（b）两组一致性效果的可比顺序调制。

结论

我们的研究结果表明，AD患者的数字能力下降，并且这种下降是由于特定领域的过程（即数字过程）和一般领域的过程（即抑制）受损导致的。这些发现对进一步理解特定和一般的认知过程如何促进数字估计/比较表现以及在阿尔茨海默氏病期间这些贡献如何变化具有重要意义。