Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China ; School of Psychology and Cognitive Science, East China Normal University, Shanghai 200062, China.
Department of Psychology, Fudan University, Shanghai 200433, China.
Neural Regen Res. 2013 Sep 15;8(26):2424-31. doi: 10.3969/j.issn.1673-5374.2013.26.003.
Episodic memories are composed of various interrelated elements, including those specific to items of central interest and those pertaining to related features, such as the color, shape, size, spatial location, temporal order, and media or modalities of presentation. Memory about a core item (such as a word, object, or picture) is called item memory while memory about the context or related fea-tures of a core item is defined as source memory. What determines which sources within an episode are successfully remembered is of particular interest to researchers. Behavioral evidence suggests that the orientation of a memory task influences whether the related source of the item will be re-membered later. This study explored changes in the hippocampus and prefrontal cortex while par-ticipants completed two tasks: an item-oriented task and a source-oriented task. We used functional MRI to investigate the neural mechanisms by which task orientation influences source encoding. We found that subsequent source memory effects in the right prefrontal cortex and hippocampus were modulated by task orientation, whereas task orientation modulated item memory effects in the prefrontal cortex. These findings highlight the possibility that the hippocampus contributes to the intentional encoding of item-source associations, whereas the prefrontal cortex is biased toward processing information to which attention is directed.
情景记忆由各种相互关联的元素组成，包括与核心项目相关的特定元素和与相关特征（如颜色、形状、大小、空间位置、时间顺序以及呈现的媒体或模态）相关的元素。关于核心项目（如单词、对象或图片）的记忆称为项目记忆，而关于核心项目的上下文或相关特征的记忆则定义为来源记忆。决定一个情景中哪些来源可以被成功记住是研究人员特别感兴趣的问题。行为证据表明，记忆任务的方向会影响以后是否会记住项目的相关来源。这项研究在参与者完成两项任务时，探索了海马体和前额叶皮层的变化：一项是面向项目的任务，另一项是面向来源的任务。我们使用功能磁共振成像来研究任务方向影响源编码的神经机制。我们发现，右前额叶皮层和海马体的后续来源记忆效应受到任务方向的调节，而任务方向调节了前额叶皮层的项目记忆效应。这些发现强调了海马体可能有助于有意图地编码项目-来源关联，而前额叶皮层则偏向于处理注意力指向的信息。
