Department of Psychology, Harvard University, USA.
Department of Psychology, University of Texas at Austin, USA.
Neuroimage. 2019 May 1;191:162-175. doi: 10.1016/j.neuroimage.2019.02.005. Epub 2019 Feb 5.
Using functional magnetic resonance imaging data, we assessed whether across-participant variability of content-selective retrieval-related neural activity differs with age. We addressed this question by employing across-participant multi-voxel pattern analysis (MVPA), predicting that increasing age would be associated with reduced variability of retrieval-related cortical reinstatement across participants. During study, 24 young and 24 older participants viewed objects and concrete words. Test items comprised studied words, names of studied objects, and unstudied words. Participants judged whether the items were recollected, familiar, or new by making 'Remember', 'Know' and 'New' responses, respectively. MVPA was conducted on each region belonging to the 'core recollection network', dorsolateral prefrontal cortex, and a previously identified content-selective voxel set. A leave-one-participant-out classification approach was employed whereby a classifier was trained on a subset of participants and tested on the data from a yoked pair of held-out participants. Classifiers were trained on the study phase data to discriminate the study trials as a function of content (picture or word). The classifiers were then applied to the test phase data to discriminate studied test words according to their study condition. In all of the examined regions, classifier performance demonstrated little or no sensitivity to age and, for the test data, was robustly above chance. Thus, there was little evidence to support the hypothesis that across-participant variability of retrieval-related cortical reinstatement differs with age. The findings extend prior evidence by demonstrating that content-selective cortical reinstatement is sufficiently invariant to support across-participant multi-voxel classification across the healthy adult lifespan.
使用功能磁共振成像数据，我们评估了内容选择检索相关神经活动的跨参与者变异性是否随年龄而变化。我们通过采用跨参与者多体素模式分析（MVPA）来解决这个问题，预测随着年龄的增长，参与者之间的检索相关皮质再激活的变异性会降低。在研究过程中，24 名年轻参与者和 24 名年长参与者观看了物体和具体单词。测试项目包括学习过的单词、学习过的物体的名称和未学习过的单词。参与者通过分别做出“记得”、“知道”和“新”的反应来判断项目是被回忆起、熟悉还是新的。对属于“核心回忆网络”、背外侧前额叶皮层以及先前确定的内容选择体素集的每个区域进行 MVPA。采用了一种离开一个参与者的分类方法，其中分类器在参与者子集上进行训练，并在一对保留参与者的配对数据上进行测试。分类器在学习阶段的数据上进行训练，以根据内容（图片或单词）区分学习试验。然后将分类器应用于测试阶段的数据，根据其学习条件区分学习的测试单词。在所有检查的区域中，分类器的性能对年龄几乎没有或没有敏感性，并且对于测试数据，其表现明显高于随机水平。因此，几乎没有证据支持跨参与者检索相关皮质再激活变异性随年龄变化的假设。这些发现通过证明内容选择皮质再激活具有足够的不变性来支持健康成年人整个生命周期的跨参与者多体素分类，扩展了先前的证据。
