Department of Psychological and Brain Sciences, Washington University in St. Louis, St. Louis, MO, USA.
VISN 17 Center of Excellence for Research on Returning War Veterans, Waco, TX, USA.
Cereb Cortex. 2018 Nov 1;28(11):4008-4022. doi: 10.1093/cercor/bhx264.
Receiving correct answer feedback following a retrieval attempt has proven to be a highly effective means of learning new information, yet the mechanisms behind its efficacy remain poorly understood. Here, fMRI was used to examine how BOLD activity measured during a period of feedback could predict subsequent memory (SM) performance on a final test. Twenty-five human subjects studied pairs of associated words, and were then asked to covertly recall target words in response to provided cues. Correct answer feedback was provided immediately after covert retrieval attempts. A partial trial design enabled separate modeling of activity related to retrieval and to feedback processing. During initial study, typical SM effects were observed across the whole brain. During feedback following a failed recall attempt, activity in only a subset of these regions predicted final test performance. These regions fell within the default mode network (DMN) and demonstrated negative SM effects, such that greater deactivation was associated with successful recall. No "task-positive" regions demonstrated SM effects in this contrast. The obtained results are consistent with a growing literature that associates DMN deactivation with successful learning in multiple task contexts, likely reflecting differences in the allocation of attentional resources during encoding.
在检索尝试后接收正确答案反馈已被证明是学习新信息的一种非常有效的方法,但它的有效性背后的机制仍未被很好地理解。在这里,fMRI 被用来研究在反馈期间测量的 BOLD 活动如何预测最终测试中的后续记忆 (SM) 表现。二十五名人类受试者学习了一对相关的单词,然后被要求在提供的提示下默默地回忆目标单词。在隐蔽检索尝试后立即提供正确答案反馈。部分试验设计能够分别对检索和反馈处理的活动进行建模。在最初的学习过程中,整个大脑都观察到了典型的 SM 效应。在失败的回忆尝试后反馈期间,只有这些区域中的一小部分的活动可以预测最终测试的表现。这些区域属于默认模式网络 (DMN),表现出负的 SM 效应,即更大的去激活与成功回忆相关。在这种对比中,没有“任务正”区域表现出 SM 效应。所获得的结果与越来越多的文献一致,这些文献将 DMN 去激活与多种任务环境中的成功学习联系起来,这可能反映了在编码过程中注意力资源分配的差异。