Department of Psychology, Keio University, 2-15-45 Mita, Minato-ku, Tokyo, Japan.
Neurobiol Learn Mem. 2011 Sep;96(2):143-9. doi: 10.1016/j.nlm.2011.03.008. Epub 2011 Apr 7.
Learning is the process of accumulating information. Repetition can make the process of retrieving information more efficient. The mechanisms by which repetition facilitates the retrieval process, however, are not yet clear. Here, we used event-related functional magnetic resonance imaging to investigate the effects of repetition on cued recall. In this study, participants were asked to encode visually presented semantically unrelated word pairs. The word presented on the left side served as the cue, and the word presented on the right side was the target. In the first test phase, participants were presented with the cue and asked to recall the associated word (target) from the study phase. The second test phase was performed 20 min later using the same method. Participants responded orally during the interval between image acquisitions, and no feedback was provided. Neural activity for identical stimuli and responses across the two tests were compared. As compared with the first test phase, the right dorsolateral prefrontal, bilateral inferior parietal, and precuneus regions showed greater activity and the left inferior frontal areas showed reduced activity during the second test phase. These shifts in neural activity that occurred with repetition may reflect the dynamics of the retrieval process.
学习是积累信息的过程。重复可以使信息检索过程更有效率。然而，重复促进检索过程的机制尚不清楚。在这里，我们使用事件相关功能磁共振成像来研究重复对提示回忆的影响。在这项研究中，参与者被要求对视觉呈现的语义上不相关的单词对进行编码。左边呈现的单词作为提示，右边呈现的单词是目标。在第一个测试阶段，参与者被呈现提示，并被要求从学习阶段回忆相关单词（目标）。第二个测试阶段在 20 分钟后以相同的方式进行。参与者在图像采集之间的间隔内口头回答，没有提供反馈。比较了两次测试中相同刺激和反应的神经活动。与第一测试阶段相比，第二测试阶段右侧背外侧前额叶、双侧下顶叶和楔前叶区域的活动增加，左侧额下回区域的活动减少。这种随着重复而发生的神经活动的变化可能反映了检索过程的动态。
