Speer Megan E, Soldan Anja
Department of Psychology, Rutgers University, Newark, NJ, USA.
Division of Cognitive Neuroscience, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Neurobiol Aging. 2015 Mar;36(3):1424-34. doi: 10.1016/j.neurobiolaging.2014.12.025. Epub 2014 Dec 29.
Although many epidemiological studies suggest the beneficial effects of higher cognitive reserve (CR) in reducing age-related cognitive decline and dementia risk, the neural basis of CR is poorly understood. To our knowledge, the present study represents the first electrophysiological investigation of the relationship between CR and neural reserve (i.e., neural efficiency and capacity). Specifically, we examined whether CR modulates event-related potentials associated with performance on a verbal recognition memory task with 3 set sizes (1, 4, or 7 letters) in healthy younger and older adults. Neural data showed that as task difficulty increased, the amplitude of the parietal P3b component during the probe phase decreased and its latency increased. Notably, the degree of these neural changes was negatively correlated with CR in both age groups, such that individuals with higher CR showed smaller changes in P3b amplitude and less slowing in P3b latency (i.e., smaller changes in the speed of neural processing) with increasing task difficulty, suggesting greater neural efficiency. These CR-related differences in neural efficiency may underlie reserve against neuropathology and age-related burden.
尽管许多流行病学研究表明较高的认知储备（CR）在降低与年龄相关的认知衰退和痴呆风险方面具有有益作用，但CR的神经基础仍知之甚少。据我们所知，本研究是对CR与神经储备（即神经效率和能力）之间关系的首次电生理研究。具体而言，我们研究了CR是否会调节健康的年轻人和老年人在执行具有3种组块大小（1、4或7个字母）的言语识别记忆任务时与表现相关的事件相关电位。神经数据显示，随着任务难度的增加，探测阶段顶叶P3b成分的波幅降低，潜伏期延长。值得注意的是，在两个年龄组中，这些神经变化的程度与CR呈负相关，即CR较高的个体在任务难度增加时，P3b波幅变化较小，P3b潜伏期减慢较少（即神经处理速度变化较小），表明神经效率更高。这些与CR相关的神经效率差异可能是抵御神经病理学和与年龄相关负担的储备基础。
