Cognitive Neuroscience Division, Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, New York, New York, USA.
Mental Health Data Science, New York State Psychiatric Institute, New York, New York, USA.
Hum Brain Mapp. 2024 Apr;45(5):e26658. doi: 10.1002/hbm.26658.
Cognitive reserve (CR) explains differential susceptibility of cognitive performance to neuropathology. However, as brain pathologies progress, cognitive decline occurs even in individuals with initially high CR. The interplay between the structural brain health (= level of brain reserve) and CR-related brain networks therefore requires further research. Our sample included 142 individuals aged 60-70 years. National Adult Reading Test intelligence quotient (NART-IQ) was our CR proxy. On an in-scanner Letter Sternberg task, we used ordinal trend (OrT) analysis to extract a task-related brain activation pattern (OrT slope) for each participant that captures increased expression with task load (one, three, and six letters). We assessed whether OrT slope represents a neural mechanism underlying CR by associating it with task performance and NART-IQ. Additionally, we investigated how the following brain reserve measures affect the association between NART-IQ and OrT slope: mean cortical thickness, total gray matter volume, and brain volumes proximal to the areas contained in the OrT patterns. We found that higher OrT slope was associated with better task performance and higher NART-IQ. Further, the brain reserve measures were not directly associated with OrT slope, but they affected the relationship between NART-IQ and OrT slope: NART-IQ was associated with OrT slope only in individuals with high brain reserve. The degree of brain reserve has an impact on how (and perhaps whether) CR can be implemented in brain networks in older individuals.
认知储备（CR）解释了认知表现对神经病理学的不同敏感性。然而，随着大脑病理学的进展，即使在最初具有高 CR 的个体中，认知能力也会下降。因此，需要进一步研究结构大脑健康（=大脑储备水平）与 CR 相关的大脑网络之间的相互作用。我们的样本包括 142 名年龄在 60-70 岁的个体。国家成人阅读测试智商（NART-IQ）是我们的 CR 代理。在扫描内的字母斯特恩伯格任务中，我们使用有序趋势（OrT）分析从每个参与者中提取出一个与任务相关的大脑激活模式（OrT 斜率），该斜率捕获了随着任务负荷的增加而增加的表达（一个、三个和六个字母）。我们通过将其与任务表现和 NART-IQ 相关联，来确定 OrT 斜率是否代表 CR 的神经机制。此外，我们研究了以下大脑储备措施如何影响 NART-IQ 和 OrT 斜率之间的关联：平均皮质厚度、总灰质体积以及与包含在 OrT 模式中的区域相邻的脑体积。我们发现，较高的 OrT 斜率与更好的任务表现和更高的 NART-IQ 相关。此外，大脑储备措施与 OrT 斜率没有直接关联，但它们影响了 NART-IQ 和 OrT 斜率之间的关系：只有在具有高大脑储备的个体中，NART-IQ 才与 OrT 斜率相关。大脑储备的程度会影响 CR 在老年人大脑网络中的实施方式（和可能的方式）。
