Department of Medical and Social Sciences, Ken and Ruth Davee Department of Neurology, and Interdepartmental Neuroscience Program, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611.
J Neurosci. 2014 Feb 5;34(6):2203-13. doi: 10.1523/JNEUROSCI.3819-13.2014.
Memory stability and change are considered opposite outcomes. We tested the counterintuitive notion that both depend on one process: hippocampal binding of memory features to associatively novel information, or associative novelty binding (ANB). Building on the idea that dominant memory features, or "traces," are most susceptible to modification, we hypothesized that ANB would selectively involve dominant traces. Therefore, memory stability versus change should depend on whether the currently dominant trace is old versus updated; in either case, novel information will be bound with it, causing either maintenance (when old) or change (when updated). People in our experiment studied objects at locations within scenes (contexts). During reactivation in a new context, subjects moved studied objects to new locations either via active location recall or by passively dragging objects to predetermined locations. After active reactivation, the new object location became dominant in memory, whereas after passive reactivation, the old object location maintained dominance. In both cases, hippocampal ANB bound the currently dominant object-location memory with a context with which it was not paired previously (i.e., associatively novel). Stability occurred in the passive condition when ANB united the dominant original location trace with an associatively novel newer context. Change occurred in the active condition when ANB united the dominant updated object location with an associatively novel and older context. Hippocampal ANB of the currently dominant trace with associatively novel contextual information thus provides a single mechanism to support memory stability and change, with shifts in trace dominance during reactivation dictating the outcome.
记忆的稳定性和变化被认为是相反的结果。我们测试了一个反直觉的观点，即两者都依赖于一个过程：海马体将记忆特征与联想新颖信息（或联想新颖绑定，ANB）绑定。基于主导记忆特征或“痕迹”最容易受到修改的想法，我们假设 ANB 将选择性地涉及主导痕迹。因此，记忆的稳定性与变化取决于当前主导痕迹是旧的还是更新的；在任何一种情况下，新信息都会与之绑定，从而导致维持（当旧的）或改变（当更新的）。我们实验中的人在场景（上下文）内的位置研究物体。在新场景中重新激活时，受试者通过主动位置回忆或被动拖动物体到预定位置将研究过的物体移动到新位置。在主动重新激活后，新的物体位置在记忆中变得占主导地位，而在被动重新激活后，旧的物体位置保持主导地位。在这两种情况下，海马体的 ANB 将当前占主导地位的物体-位置记忆与之前未配对的上下文（即联想新颖的）绑定。当 ANB 将主导的原始位置痕迹与联想新颖的更新上下文结合在一起时，被动条件下会出现稳定性。当 ANB 将主导的更新物体位置与联想新颖且较旧的上下文结合在一起时，主动条件下会发生变化。因此，海马体 ANB 与联想新颖的上下文信息结合当前主导的痕迹提供了一种单一的机制来支持记忆的稳定性和变化，重新激活期间痕迹主导地位的转变决定了结果。
