Dockree Paul M, Brennan Sabina, O'Sullivan Michael, Robertson Ian H, O'Connell Redmond G
Trinity College Institute of Neuroscience & School of Psychology, Trinity College, Dublin, Ireland.
Trinity College Institute of Neuroscience & School of Psychology, Trinity College, Dublin, Ireland.
Brain Cogn. 2015 Jul;97:40-50. doi: 10.1016/j.bandc.2015.04.002. Epub 2015 May 24.
While aging is associated with a gradual decline in memory, substantial preservation of function is observed in certain individuals and dissecting this heterogeneity is paramount to understanding successful aging. A cohort of elderly individuals were classified according to their level of memory preservation and administered a test of episodic memory in which participants were cued to learn or simply read each word and then to identify previously presented items in a delayed recognition phase. Mathematical modelling revealed that relatively preserved memory function was specifically linked to a faster rate of memorial evidence accumulation (drift rate). Analysis of event-related potentials at encoding revealed that high-performing elderly exhibited signals over parietal regions that discriminated between words to be learned vs. read for an additional 300-ms compared to young subjects suggesting a compensatory encoding mechanism that was absent in the low-performing group. At recognition, parietal signals associated with recollection processes discriminated previously learned words from read words in the young and high-performing old but not in low-performing old. These results reveal that successful aging is associated with specific adaptive neural markers during both encoding and retrieval.
虽然衰老与记忆力逐渐衰退有关，但在某些个体中观察到功能的大量保留，剖析这种异质性对于理解成功衰老至关重要。一组老年人根据其记忆保留水平进行分类，并进行了一项情景记忆测试，在测试中，参与者被提示学习或简单阅读每个单词，然后在延迟识别阶段识别之前呈现的项目。数学建模显示，相对保留的记忆功能与更快的记忆证据积累速度（漂移率）特别相关。对编码时的事件相关电位分析表明，与年轻受试者相比，表现良好的老年人在顶叶区域表现出信号，该信号能够区分要学习的单词和要阅读的单词，且持续时间额外多出300毫秒，这表明低表现组中不存在的一种补偿性编码机制。在识别时，与回忆过程相关的顶叶信号在年轻组和表现良好的老年组中能够区分之前学习的单词和阅读的单词，但在低表现的老年组中则不能。这些结果表明，成功衰老与编码和检索过程中特定的适应性神经标记有关。
