Bowman Caitlin R, Dennis Nancy A
The Department of Psychology, The Pennsylvania State University, University Park, PA 16802, USA.
Brain Res. 2015 Jul 1;1612:2-15. doi: 10.1016/j.brainres.2014.08.006. Epub 2014 Aug 19.
Past research finds that age-related increases in false recognitions are a key contributor to age-related memory decline, suggesting that older adults have difficulty in correctly distinguishing between new and old information, particularly when new items at retrieval are semantically or perceptually related to items from encoding. However, little work has examined the neural mechanisms older adults engage to avoid false recognitions and successfully identify information as novel. In the present study, young and older adults were scanned during a retrieval task in which new items were exemplars from studied categories (related lures) or unstudied categories (unrelated lures) in order to detect age-related differences in the neural correlates of related and unrelated novelty processing. Results showed that, unlike young adults, older adults did not differentially recruit regions such as the anterior cingulate and bilateral middle/inferior temporal gyrus to capitalize on the salient categorical differences in unrelated items. Likewise, older adults did not differentially recruit regions of early visual cortex or anterior hippocampus, suggesting that older adults have difficulty using item-specific details to make successful related novelty decisions. Instead, older adults recruited bilateral ventrolateral prefrontal cortex differentially for successful novelty processing and particularly for related novelty processing. Overall, results suggest that age deficits in novelty processing may arise because older adults process related and unrelated lures similarly and do not capitalize on categorical or item-specific properties of novel items. Similar to aging patterns in memory retrieval, results also showed that older adults have the strongest novelty success activity in lateral PFC regions associated with control and monitoring processes. This article is part of a Special Issue entitled SI: Memory & Aging.
以往的研究发现，与年龄相关的错误识别增加是导致与年龄相关的记忆衰退的关键因素，这表明老年人在正确区分新信息和旧信息方面存在困难，尤其是当检索时的新项目在语义或感知上与编码时的项目相关时。然而，很少有研究探讨老年人为避免错误识别并成功将信息识别为新信息而采用的神经机制。在本研究中，年轻和年长的成年人在一项检索任务中接受扫描，在该任务中，新项目是来自已研究类别的示例（相关诱饵）或未研究类别的示例（不相关诱饵），以便检测与年龄相关的在相关和不相关新颖性处理的神经关联方面的差异。结果表明，与年轻人不同，老年人没有差异地激活诸如前扣带回和双侧中/颞下回等区域，以利用不相关项目中显著的类别差异。同样，老年人也没有差异地激活早期视觉皮层或前海马体区域，这表明老年人在利用特定项目的细节做出成功的相关新颖性决策方面存在困难。相反，老年人在成功进行新颖性处理，特别是相关新颖性处理时，差异地激活双侧腹外侧前额叶皮层。总体而言，结果表明新颖性处理中的年龄缺陷可能是因为老年人对相关和不相关诱饵的处理方式相似，并且没有利用新事物的类别或特定项目属性。与记忆检索中的衰老模式类似，结果还表明，老年人在与控制和监测过程相关的外侧前额叶皮层区域具有最强的新颖性成功活动。本文是名为“SI：记忆与衰老”的特刊的一部分。
