Wig Gagan S, Grafton Scott T, Demos Kathryn E, Wolford George L, Petersen Steven E, Kelley William M
Department of Psychological & Brain Sciences, Dartmouth College, Hanover, NH 03755, USA.
Proc Natl Acad Sci U S A. 2008 Nov 25;105(47):18555-60. doi: 10.1073/pnas.0804546105. Epub 2008 Nov 10.
Human beings differ in their ability to form and retrieve lasting long-term memories. To explore the source of these individual differences, we used functional magnetic resonance imaging to measure blood-oxygen-level-dependent (BOLD) activity in healthy young adults (n = 50) during periods of resting fixation that were interleaved with periods of simple cognitive tasks. We report that medial temporal lobe BOLD activity during periods of rest predicts individual differences in memory ability. Specifically, individuals who exhibited greater magnitudes of task-induced deactivations in medial temporal lobe BOLD signal (as compared to periods of rest) demonstrated superior memory during offline testing. This relationship was independent of differences in general cognitive function and persisted across different control tasks (i.e., number judgment versus checkerboard detection) and experimental designs (i.e., blocked versus event-related). These results offer a neurophysiological basis for the variability in mnemonic ability that is present amongst healthy young adults and may help to guide strategies aimed at early detection and intervention of neurological and mnemonic impairment.
人类在形成和提取持久的长期记忆的能力上存在差异。为了探究这些个体差异的根源，我们使用功能磁共振成像技术，在健康的年轻成年人（n = 50）进行静息注视期间（其间穿插简单认知任务阶段），测量其血氧水平依赖（BOLD）活动。我们报告称，静息期内侧颞叶的BOLD活动可预测记忆能力的个体差异。具体而言，在离线测试中，内侧颞叶BOLD信号中任务诱发失活幅度更大（与静息期相比）的个体表现出更优的记忆力。这种关系独立于一般认知功能的差异，并且在不同的控制任务（即数字判断与棋盘检测）和实验设计（即组块设计与事件相关设计）中均持续存在。这些结果为健康年轻成年人中存在的记忆能力变异性提供了神经生理学基础，并可能有助于指导旨在早期检测和干预神经及记忆障碍的策略。
