Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany; Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
Neuroimage. 2015 Sep;118:146-53. doi: 10.1016/j.neuroimage.2015.06.002. Epub 2015 Jun 5.
Associative memory involves binding two or more items into a coherent memory episode. Relative to memory for single items, associative memory declines greatly in aging. However, older individuals vary substantially in their ability to memorize associative information. Although functional studies link associative memory to the medial temporal lobe (MTL) and prefrontal cortex (PFC), little is known about how volumetric differences in MTL and PFC might contribute to individual differences in associative memory. We investigated regional gray-matter volumes related to individual differences in associative memory in a sample of healthy older adults (n=54; age=60years). To differentiate item from associative memory, participants intentionally learned face-scene picture pairs before performing a recognition task that included single faces, scenes, and face-scene pairs. Gray-matter volumes were analyzed using voxel-based morphometry region-of-interest (ROI) analyses. To examine volumetric differences specifically for associative memory, item memory was controlled for in the analyses. Behavioral results revealed large variability in associative memory that mainly originated from differences in false-alarm rates. Moreover, associative memory was independent of individuals' ability to remember single items. Older adults with better associative memory showed larger gray-matter volumes primarily in regions of the left and right lateral PFC. These findings provide evidence for the importance of PFC in intentional learning of associations, likely because of its involvement in organizational and strategic processes that distinguish older adults with good from those with poor associative memory.
联想记忆涉及将两个或多个项目绑定到一个连贯的记忆事件中。与单个项目的记忆相比，联想记忆在衰老过程中会大大下降。然而，老年人在记忆联想信息的能力上有很大的差异。尽管功能研究将联想记忆与内侧颞叶（MTL）和前额叶皮层（PFC）联系起来，但对于 MTL 和 PFC 的体积差异如何导致联想记忆的个体差异知之甚少。我们在一组健康老年人样本中（n=54；年龄=60 岁）研究了与联想记忆个体差异相关的区域灰质体积。为了区分项目和联想记忆，参与者在执行识别任务之前，有意学习人脸-场景图片对，该任务包括单个面孔、场景和人脸-场景对。使用基于体素的形态计量学 ROI 分析来分析灰质体积。为了专门检查与联想记忆相关的体积差异，在分析中控制了项目记忆。行为结果显示，联想记忆的可变性很大，主要源于虚报率的差异。此外，联想记忆与个体记住单个项目的能力无关。具有更好联想记忆的老年人表现出更大的灰质体积，主要位于左侧和右侧外侧前额叶皮层的区域。这些发现为 PFC 在联想的有意学习中的重要性提供了证据，可能是因为它参与了区分具有良好和较差联想记忆的老年人的组织和策略过程。
