Separable prefrontal cortex contributions to free recall.
Separable prefrontal cortex contributions to free recall.
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DOI：
10.1523/jneurosci.2611-10.2010
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发表时间：
2010-08-18
期刊：
影响因子：
--
通讯作者：
Badre D
中科院分区：
文献类型：
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作者：
Long NM;Oztekin I;Badre D
在日常生活中，我们经常必须在环境中缺乏有用线索的情况下记住过去。在这些情况下，大脑依靠内部保持的线索和策略来指导检索。自由回忆是一种被广泛应用的研究最小线索条件下提取的行为范式。在自由回忆过程中，个体经常回忆起语义相关的项目召唤式的效果称为语义聚类和以前的研究试图了解聚类，以获得杠杆的基本机制支持战略回忆。成功的回忆和语义聚类依赖于前额叶皮层（PFC）。然而，由于方法的局限性，很少有功能性磁共振成像（fMRI）研究评估了支持随后回忆的编码神经机制，也没有测试回忆本身的事件相关性。因此，在编码和回忆过程中是否有一个或几个额叶控制机制起作用仍然是个问题。在这里，我们采用了最近开发的方法来评估自由回忆过程中事件相关的fMRI信号的变化。在编码过程中，背外侧前额叶皮层（DLPFC）的激活是预测随后的语义聚类。与此相反，腹外侧前额叶皮层（VLPFC）的子区域预测随后的回忆，无论是集群或非集群，并在回忆过程中与集群呈负相关。这些结果表明，DLPFC支持关系过程中的编码，足以产生类别聚类效应在回忆。相反，VLPFC支持的受控检索机制支持在回忆过程中的项目特定的搜索。
In everyday life, we often must remember the past in the absence of helpful cues in the environment. In these cases, the brain directs retrieval by relying on internally maintained cues and strategies. Free recall is a widely used behavioral paradigm for studying retrieval with minimal cue support. During free recall, individuals often recall semantically related items consecutively—an effect termed semantic clustering—and previous studies have sought to understand clustering to gain leverage on the basic mechanisms supporting strategic recall. Successful recall and semantic clustering depend on the prefrontal cortex (PFC). However, as a result of methodological limitations, few functional magnetic resonance imaging (fMRI) studies have assessed the neural mechanisms at encoding that support subsequent recall, and none have tested the event-related correlates of recall itself. Thus, it remains open whether one or several frontal control mechanisms operate during encoding and recall. Here, we applied a recently developed method to assess event-related fMRI signal changes during free recall. During encoding, dorsolateral prefrontal cortex (DLPFC) activation was predictive of subsequent semantic clustering. In contrast, subregions of ventrolateral prefrontal cortex (VLPFC) were predictive of subsequent recall, whether clustered or nonclustered, and were inversely associated with clustering during recall. These results suggest that DLPFC supports relational processes at encoding that are sufficient to produce category clustering effects during recall. Conversely, controlled retrieval mechanisms supported by VLPFC support item-specific search during recall.