Department of Psychology, New York University, New York, NY, USA.
Department of Psychology, Boston College, MA, USA.
Cereb Cortex. 2019 Jul 22;29(8):3305-3318. doi: 10.1093/cercor/bhy200.
Memory retrieval can strengthen, but also distort memories. Parietal cortex is a candidate region involved in retrieval-induced memory changes as it reflects retrieval success and represents retrieved content. Here, we conducted an fMRI experiment to test whether different forms of parietal reactivation predict distinct consequences of retrieval. Subjects studied associations between words and pictures of faces, scenes, or objects, and then repeatedly retrieved half of the pictures, reporting the vividness of the retrieved pictures ("retrieval practice"). On the following day, subjects completed a recognition memory test for individual pictures. Critically, the test included lures highly similar to studied pictures. Behaviorally, retrieval practice increased both hit and false alarm (FA) rates to similar lures, confirming a causal influence of retrieval on subsequent memory. Using pattern similarity analyses, we measured two different levels of reactivation during retrieval practice: generic "category-level" reactivation and idiosyncratic "item-level" reactivation. Vivid remembering during retrieval practice was associated with stronger category- and item-level reactivation in parietal cortex. However, these measures differentially predicted subsequent recognition memory performance: whereas higher category-level reactivation tended to predict FAs to lures, item-level reactivation predicted correct rejections. These findings indicate that parietal reactivation can be decomposed to tease apart distinct consequences of memory retrieval.
记忆提取既能增强，也能扭曲记忆。顶叶皮层是参与提取诱导记忆变化的候选区域，因为它反映了提取的成功并代表了提取的内容。在这里，我们进行了一项 fMRI 实验，以测试不同形式的顶叶再激活是否预测了提取的不同后果。被试学习了单词和人脸、场景或物体图片之间的关联，然后反复提取一半的图片，报告所提取图片的生动程度（检索练习）。第二天，被试完成了对个别图片的识别记忆测试。关键是，测试中包括与学习图片高度相似的诱饵。行为上，检索练习增加了对类似诱饵的击中率和错误警报（FA）率，这证实了检索对随后记忆的因果影响。使用模式相似性分析，我们在检索练习过程中测量了两种不同水平的再激活：通用的“类别水平”再激活和特有的“项目水平”再激活。检索练习过程中生动的记忆与顶叶皮层中更强的类别和项目水平的再激活有关。然而，这些测量结果对随后的识别记忆表现有不同的预测：虽然较高的类别水平再激活倾向于预测诱饵的 FA，但项目水平再激活预测了正确的拒绝。这些发现表明，顶叶再激活可以被分解开来，以区分记忆提取的不同后果。
