Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, 405 N Mathews Avenue, Urbana, IL 61801, USA.
Neuropsychologia. 2011 Dec;49(14):3956-66. doi: 10.1016/j.neuropsychologia.2011.10.012. Epub 2011 Oct 15.
Memory retrieval can involve activity in the same sensory cortical regions involved in perception of the original event, and this neural "reactivation" has been suggested as an important mechanism of memory retrieval. However, it is still unclear if fragments of experience other than sensory information are retained and later reactivated during retrieval. For example, learning in non-laboratory settings generally involves active exploration of memoranda, thus requiring the generation of action plans for behavior and the use of strategies deployed to improve subsequent memory performance. Is information pertaining to action planning and strategic processing retained and reactivated during retrieval? To address this question, we compared ERP correlates of memory retrieval for objects that had been studied in an active manner involving action planning and strategic processing to those for objects that had been studied passively. Memory performance was superior for actively studied objects, and unique ERP retrieval correlates for these objects were identified when subjects remembered the specific spatial locations at which objects were studied. Early-onset frontal shifts in ERP correlates of retrieval were noted for these objects, which parallel the recruitment of frontal cortex during learning object locations previously identified using fMRI with the same paradigm. Notably, ERPs during recall for items studied with a specific viewing strategy localized to the same supplementary motor cortex region previously identified with fMRI when this strategy was implemented during study, suggesting rapid reactivation of regions directly involved in strategic action planning. Collectively, these results implicate neural populations involved in learning in important retrieval functions, even for those populations involved in strategic control and action planning. Notably, these episodic features are not generally reported during recollective experiences, suggesting that reactivation is a more general property of memory retrieval that extends beyond those fragments of perceptual information that might be needed to re-live the past.
记忆检索可能涉及到与原始事件感知相关的相同感觉皮层区域的活动，这种神经“再激活”被认为是记忆检索的重要机制。然而，目前仍不清楚在检索过程中是否会保留除感觉信息以外的其他经验片段并进行再激活。例如，在非实验室环境中的学习通常涉及对记忆材料的主动探索，因此需要生成行为计划，并使用策略来提高后续的记忆表现。在检索过程中，是否会保留与动作规划和策略处理相关的信息并进行再激活？为了解决这个问题，我们比较了主动参与动作规划和策略处理的研究对象的记忆检索的 ERP 相关物，以及被动研究对象的记忆检索的 ERP 相关物。主动研究的对象的记忆表现更好，并且当受试者记住对象被研究的特定空间位置时，这些对象的独特 ERP 检索相关物被识别出来。这些对象的 ERP 检索相关物中注意到早期的额前转移，这与使用相同范式的 fMRI 先前确定的学习对象位置期间前额叶皮层的招募相平行。值得注意的是，当在研究期间实施特定的观看策略时，研究对象的回忆中 ERPs 定位于先前使用 fMRI 确定的相同辅助运动皮层区域，这表明与战略行动规划直接相关的区域的快速再激活。总之，这些结果表明，即使是涉及战略控制和动作规划的那些神经群体，在学习中也涉及到重要的检索功能。值得注意的是，这些情节特征通常不会在回忆经历中报告，这表明再激活是记忆检索的一个更普遍的属性，它不仅限于那些可能需要重新体验过去的感知信息片段。
