Lucas Heather D, Gupta Resh S, Hubbard Ryan J, Federmeier Kara D
Department of Psychology, Louisiana State University, Baton Rouge, LA, United States.
Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, United States.
Front Hum Neurosci. 2019 Oct 10;13:339. doi: 10.3389/fnhum.2019.00339. eCollection 2019.
It is well-established that aging impairs memory for associations more than it does memory for single items. Aging also impacts processes involved in online language comprehension, including the ability to form integrated, message-level representations. These changes in comprehension processes could impact older adults' associative memory performance, perhaps by reducing or altering the effectiveness of encoding strategies that encourage semantic integration. The present study examined age differences in the use of a strategy termed conceptual combination, which involves integrating two words (e.g., "winter" and "salad") into a single concept ("a salad for winter"). We recorded ERPs while participants studied unrelated noun pairs using a strategy that either did or did not encourage conceptual combination. We also varied the concreteness of the first noun in each pair in order to measure compositional concreteness effects, or ERP differences at the second noun due to the concreteness of the first noun. At the first nouns, older adults showed word-level concreteness effects that were similar to those of younger adults. However, compositional concreteness effects were diminished in older adults, consistent with reduced semantic integration. Older adults' associative memory performance was better for word pairs studied during the conceptual combination task versus the non-combinatory encoding task; however, the magnitude of the age-related associative memory deficit did not differ between tasks. Finally, analyses of both memory accuracy and trial-by-trial ratings of perceived combination success suggested that older adults had disproportionate difficulty applying the conceptual combination strategy to word pairs that began with abstract nouns. Overall, these results indicate that changes to integrative language processing that occur with age are not independent of - and may sometimes exacerbate - age-related memory decline.
众所周知，衰老对联想记忆的损害比对单个项目记忆的损害更大。衰老还会影响在线语言理解过程，包括形成整合的、信息层面表征的能力。这些理解过程的变化可能会影响老年人的联想记忆表现，也许是通过减少或改变鼓励语义整合的编码策略的有效性。本研究考察了一种称为概念组合的策略使用中的年龄差异，该策略涉及将两个词（如“冬天”和“沙拉”）整合为一个单一概念（“冬季沙拉”）。当参与者使用鼓励或不鼓励概念组合的策略研究不相关的名词对时，我们记录了他们的事件相关电位（ERP）。我们还改变了每对中第一个名词的具体性，以测量组合具体性效应，即由于第一个名词的具体性而在第二个名词上产生的ERP差异。在第一个名词上，老年人表现出与年轻人相似的词级具体性效应。然而，老年人的组合具体性效应减弱，这与语义整合减少一致。与非组合编码任务相比，老年人在概念组合任务中研究的词对的联想记忆表现更好；然而，任务之间与年龄相关的联想记忆缺陷的程度没有差异。最后，对记忆准确性和逐次试验的感知组合成功评分的分析表明，老年人在将概念组合策略应用于以抽象名词开头的词对时存在不成比例的困难。总体而言，这些结果表明，随着年龄增长而发生的整合语言处理变化并非独立于与年龄相关的记忆衰退，有时可能会加剧这种衰退。
