Department of Psychology, University of Missouri-St. Louis, St. Louis, MO 63121, USA.
Neuroimage. 2012 Sep;62(3):1956-64. doi: 10.1016/j.neuroimage.2012.06.017. Epub 2012 Jun 19.
Impairments in the ability to recollect specific details of personally experienced events are one of the main cognitive changes associated with aging. Cognitive training can improve older adults' recollection. However, little is currently known regarding the neural correlates of these training-related changes in recollection. Prior research suggests that the hippocampus plays a central role in supporting recollection in young and older adults, and that age-related changes in hippocampal function may lead to age-related changes in recollection. The present study investigated whether cognitive training-related increases in older adults' recollection are associated with changes in their hippocampal activity during memory retrieval. Older adults' hippocampal activity during retrieval was examined before and after they were trained to use semantic encoding strategies to intentionally encode words. Training-related changes in recollection were positively correlated with training-related changes in activity for old words in the hippocampus bilaterally. Positive correlations were also found between training-related changes in activity in prefrontal and left lateral temporal regions associated with self-initiated semantic strategy use during encoding and training-related changes in right hippocampal activity associated with recollection during retrieval. These results suggest that cognitive training-related improvements in older adults' recollection can be supported by changes in their hippocampal activity during retrieval. They also suggest that age differences in cognitive processes engaged during encoding are a significant contributor to age differences in recollection during retrieval.
记忆特定个人经历的能力下降是衰老相关的主要认知变化之一。认知训练可以提高老年人的记忆能力。然而，目前对于记忆训练相关变化的神经相关性知之甚少。先前的研究表明，海马体在支持年轻人和老年人的记忆方面起着核心作用，并且海马体功能的年龄相关性变化可能导致记忆的年龄相关性变化。本研究调查了老年人的记忆能力是否与他们在记忆检索过程中海马体活动的变化有关。在老年人接受使用语义编码策略有意编码单词的认知训练之前和之后，检查了他们在检索过程中海马体的活动。记忆的训练相关变化与海马体双侧旧词的活动的训练相关变化呈正相关。在与自我启动语义策略使用相关的额前和左侧颞叶区域的活动以及与检索期间记忆相关的右侧海马体活动的训练相关变化之间也发现了正相关。这些结果表明，记忆检索过程中海马体活动的变化可以支持老年人记忆能力的训练相关提高。它们还表明，在编码过程中涉及的认知过程的年龄差异是检索期间记忆的年龄差异的重要原因。
