Johnson Marcia K, Kuhl Brice A, Mitchell Karen J, Ankudowich Elizabeth, Durbin Kelly A
Department of Psychology and Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA,
Cogn Affect Behav Neurosci. 2015 Sep;15(3):644-61. doi: 10.3758/s13415-015-0352-9.
Although older adults often show reduced episodic memory accuracy, their ratings of the subjective vividness of their memories often equal or even exceed those of young adults. Such findings suggest that young and older adults may differentially access and/or weight different kinds of information in making vividness judgments. We examined this idea using multivoxel pattern classification of fMRI data to measure category representations while participants saw and remembered pictures of objects and scenes. Consistent with our hypothesis, there were age-related differences in how category representations related to the subjective sense of vividness. During remembering, older adults' vividness ratings were more related, relative to young adults', to category representations in prefrontal cortex. In contrast, young adults' vividness ratings were more related, relative to older adults, to category representations in parietal cortex. In addition, category representations were more correlated among posterior regions in young than in older adults, whereas correlations between PFC and posterior regions did not differ between the 2 groups. Together, these results are consistent with the idea that young and older adults differentially weight different types of information in assessing subjective vividness of their memories.
尽管老年人的情景记忆准确性往往会下降，但他们对记忆主观生动性的评分通常与年轻人相当，甚至超过年轻人。这些发现表明，年轻人和老年人在做出生动性判断时，可能会以不同的方式获取和/或权衡不同类型的信息。我们使用功能磁共振成像（fMRI）数据的多体素模式分类来测量类别表征，以此检验了这一想法，在此过程中，参与者观看并记忆物体和场景的图片。与我们的假设一致，在类别表征与主观生动感的关系方面存在年龄差异。在记忆过程中，相对于年轻人，老年人的生动性评分与前额叶皮层中的类别表征更为相关。相比之下，相对于老年人，年轻人的生动性评分与顶叶皮层中的类别表征更为相关。此外，年轻人后脑部区域之间的类别表征相关性高于老年人，而两组之间前额叶皮层与后脑部区域之间的相关性并无差异。总之，这些结果与以下观点一致，即年轻人和老年人在评估记忆的主观生动性时，会以不同的方式权衡不同类型的信息。
