Wales Institute of Cognitive Neuroscience, Cardiff University, Cardiff, Wales, United Kingdom.
J Neurosci. 2010 May 19;30(20):7099-104. doi: 10.1523/JNEUROSCI.0345-10.2010.
The neural substrates of memory for when events occurred are not well described. One reason for this is that the paradigms used to date have permitted isolation of only some of the relevant memory processes. In this experiment, functional magnetic resonance imaging was used to identify for the first time brain regions that support two distinct bases upon which "when" judgments can be made. Seventeen human participants (6 male) completed a continuous recognition memory task where the interval between presentation and re-presentation of words varied between 5 and 25 intervening words (the lag). The task on each trial was to distinguish repeated words from those presented for the first time, and to indicate the lag for repeated words. The inferior parietal lobe showed greater activation for shorter lag judgments, regardless of judgment accuracy. The lingual gyrus, by contrast, was more active for correct than for incorrect lag judgments, regardless of the interval between first and second item presentations. Both of these regions have been linked in previous work to the process of recollection, and the findings described here represent a novel neural dissociation across regions that deploy mnemonic information in fundamentally different ways to support judgments about when events occurred.
记忆事件发生时间的神经基础尚未得到很好的描述。原因之一是，迄今为止使用的范式仅允许分离出一些相关的记忆过程。在这项实验中，首次使用功能磁共振成像技术确定了支持“何时”判断的两个不同基础的大脑区域。17 名人类参与者（6 名男性）完成了一项连续识别记忆任务，其中单词的呈现和再现之间的间隔在 5 到 25 个插入单词之间变化（延迟）。在每次试验中，任务是区分重复的单词和首次呈现的单词，并指示重复单词的延迟。无论判断准确性如何，下顶叶都显示出对较短延迟判断的更大激活。相比之下，舌回在正确的延迟判断中比在错误的延迟判断中更活跃，而不管第一个和第二个项目呈现之间的间隔如何。这两个区域在以前的工作中都与回忆过程有关，这里描述的发现代表了在以根本不同的方式部署记忆信息以支持关于事件发生时间的判断的区域之间的新的神经分离。
