Functional Neuroimaging Unit, C.R.I.U.G.M., Montreal, Quebec, Canada.
McConnell Brain Imaging Center, Montreal Neurological Institute, Montreal, Quebec, Canada.
PLoS One. 2019 Jan 17;14(1):e0210876. doi: 10.1371/journal.pone.0210876. eCollection 2019.
Reconsolidation theory posits that upon retrieval, consolidated memories are destabilized and need to be restabilized in order to persist. It has been suggested that experience with a competitive task immediately after memory retrieval may interrupt these restabilization processes leading to memory loss. Indeed, using a motor sequence learning paradigm, we have recently shown that, in humans, interference training immediately after active task-based retrieval of the consolidated motor sequence knowledge may negatively affect its performance levels. Assessing changes in tapping pattern before and after interference training, we also demonstrated that this performance deficit more likely indicates a genuine memory loss rather than an initial failure of memory retrieval. Here, applying a similar approach, we tested the necessity of the hypothetical retrieval-induced destabilization of motor memory to allow its impairment. The impact of memory retrieval on performance of a new motor sequence knowledge acquired during the interference training was also evaluated. Similar to the immediate post-retrieval interference, interference training alone without the preceding active task-based memory retrieval was also associated with impairment of the pre-established motor sequence memory. Performance levels of the sequence trained during the interference training, on the other hand, were impaired only if this training was given immediately after memory retrieval. Noteworthy, an 8-hour interval between memory retrieval and interference allowed to express intact performance levels for both sequences. The current results suggest that susceptibility of the consolidated motor memory to behavioral interference is independent of its active task-based retrieval. Differential effects of memory retrieval on performance levels of the new motor sequence encoded during the interference training further suggests that memory retrieval may influence the way new information is stored by facilitating its integration within the retrieved memory trace. Thus, impairment of the pre-established motor memory may reflect interference from a competing memory trace rather than involve interruption of reconsolidation.
再巩固理论认为，记忆在被提取后会变得不稳定，需要重新稳定下来才能持续存在。有研究表明，在记忆提取后立即进行竞争性任务的体验可能会中断这些重新稳定过程，导致记忆丧失。事实上，我们最近使用运动序列学习范式表明，在人类中，在主动基于任务的记忆检索后立即进行干扰训练可能会对运动序列知识的表现水平产生负面影响。通过评估干扰训练前后的敲击模式变化，我们还证明了这种表现缺陷更可能表明是真正的记忆丧失，而不是记忆检索的初始失败。在这里，我们应用类似的方法来测试运动记忆的假设检索诱导不稳定性对其损伤的必要性。还评估了记忆检索对在干扰训练中获得的新运动序列知识的性能的影响。类似于即时的记忆检索干扰，没有先前主动基于任务的记忆检索的单独干扰训练也与预先建立的运动序列记忆损伤有关。另一方面，如果在记忆检索后立即进行训练，干扰训练期间训练的序列的性能水平只会受到损害。值得注意的是，在记忆检索和干扰之间有 8 小时的间隔可以使两个序列的表现水平保持完整。当前的结果表明，巩固的运动记忆对行为干扰的敏感性与其主动基于任务的检索无关。记忆检索对在干扰训练期间编码的新运动序列的性能水平的不同影响进一步表明，记忆检索可以通过促进新信息与检索到的记忆痕迹的整合来影响新信息的存储方式。因此，预先建立的运动记忆的损伤可能反映了来自竞争记忆痕迹的干扰，而不是涉及再巩固的中断。
