Department of Psychological Sciences, Kansas State University, Manhattan, Kansas, United States of America.
School of Psychology, Keele University, Keele, England.
PLoS One. 2019 Jul 31;14(7):e0220526. doi: 10.1371/journal.pone.0220526. eCollection 2019.
Previous work supports an age-specific impairment for recognition memory of pairs of words and other stimuli. The present study tested the generalization of an associative deficit across word, name, and nonword stimulus types in younger and older adults. Participants completed associative and item memory tests in one of three stimulus conditions and made metacognitive ratings of perceptions of self-efficacy, task success ("postdictions"), strategy success, task effort, difficulty, fatigue, and stamina. Surprisingly, no support was found for an age-related associative deficit on any of the stimulus types. We analyzed our data further using a multilayer perceptron artificial neural network. The network was trained to classify individuals as younger or older and its hidden unit activities were examined to identify data patterns that distinguished younger from older participants. Analysis of hidden unit activities revealed that the network was able to correctly classify by identifying three different clusters of participants, with two qualitatively different groups of older individuals. One cluster of older individuals found the tasks to be relatively easy, they believed they had performed well, and their beliefs were accurate. The other cluster of older individuals found the tasks to be difficult, believed they were performing relatively poorly, yet their beliefs did not map accurately onto their performance. Crucially, data from the associative task were more useful for neural networks to discriminate between younger and older adults than data from the item task. This work underscores the importance of considering both individual and age differences as well as metacognitive responses in the context of associative memory paradigms.
先前的研究支持特定年龄的单词和其他刺激对识别记忆的损害。本研究在年轻和老年成年人中测试了跨单词、名称和非单词刺激类型的联想缺陷的泛化。参与者在三种刺激条件之一中完成联想和项目记忆测试，并对自我效能感、任务成功（“预测”）、策略成功、任务努力、难度、疲劳和耐力的感知进行元认知评分。令人惊讶的是，对于任何刺激类型，都没有发现与年龄相关的联想缺陷。我们使用多层感知机人工神经网络进一步分析了我们的数据。该网络被训练为将个体分类为年轻或年长，并检查其隐藏单元活动，以识别区分年轻和年长参与者的数据模式。隐藏单元活动的分析表明，该网络能够通过识别三个不同的参与者集群来正确分类，其中有两个不同质的老年人群体。一个老年人群体认为任务相对容易，他们相信自己表现出色，而且他们的信念是准确的。另一个老年人群体认为任务很困难，相信自己表现相对较差，但他们的信念与表现并不准确对应。至关重要的是，与项目任务相比，联想任务的数据对于神经网络在年轻和老年人之间进行区分更有用。这项工作强调了在联想记忆范式中考虑个体和年龄差异以及元认知反应的重要性。
