Motor memory interference

动作学习是通过动作练习提高动作技能的过程。练习对于学习运动技能是必不可少的，因为在练习过程中，神经系统对感觉运动信息进行编码，这些信息用于加工运动记忆。然而，神经系统并没有随着练习的结束而停止处理信息。在练习运动任务（A）之后，在练习过程中编码的信息在大脑中被巩固为运动记忆的形式。如果巩固成功，在练习A的过程中编码的记忆会变得更加稳定，从而导致A的保留，甚至在没有额外训练的情况下，在练习会话之间的技能表现会进一步提高。然而，在巩固的初始阶段，运动记忆仍然很脆弱，如果不久之后进行第二个运动任务（B），可能会发生记忆干扰。B的性能可能导致两种类型的干扰：逆行和顺行干扰。当B的练习破坏A的巩固时发生逆行干扰，当B的练习损害A在保留时的表现时发生顺行干扰。当干扰发生时，记忆不能正确巩固，对先前学习的保留（A）受到损害。记忆干扰是研究记忆形成过程的一个有用的实验工具，因为它允许测试记忆痕迹在其巩固过程中的强度，然而，其潜在的机制还没有得到很好的理解。我的研究项目的短期目标是进行4项研究，这些研究使用通过行为和非侵入性脑刺激技术应用的记忆干扰范例，以发现健康老龄化背景下记忆干扰的神经生理学机制。研究1探讨了皮质脊髓神经元之间的耦合是否会因逆行和顺行干扰而发生变化。研究2探讨了初级运动皮层对干扰的敏感性是否与记忆巩固的速度有关。研究3探讨了对参与处理不同类型记忆的大脑网络的抑制是否会改变对不同记忆系统之间干扰的敏感性。研究4调查是否长时程增强，记忆形成的基板，预测干扰。我的研究计划的长期目标是创建一个新的框架来解释记忆干扰。该框架认为，干扰的产生是由于主要任务（A）和干扰任务（B）之间对神经网络和资源的竞争。当记忆表征之间不存在重叠并且引出2个独立的神经元池时，两个记忆痕迹可以平行地合并并且不发生干扰。相反，当整合需要相同的突触池时，就会发生干扰。

Motor learning is the process of improving the performance of motor skills through motor practice. Practice is essential for learning motor skills because it is during practice that the nervous system encodes the sensorimotor information, which is used for the elaboration of motor memories. However, the nervous system does not stop processing information with the end of practice. After practicing a motor task (A), the information encoded during practice is consolidated within the brain as a form of motor memory. If consolidation is successful, the memory encoded during the practice of A becomes more stable, leading to the retention of A or even to further improvements in skill performance between practice sessions without additional training. During the initial stages of consolidation, however, motor memories are still fragile and if a second motor task (B) is practiced soon after, memory interference may occur. The performance of B may result in two types of interference: retrograde and anterograde interference. Retrograde interference occurs when the practice of B disrupts the consolidation of A and anterograde interference when the practice of B impairs the performance of A at retention. When interference occurs, memories do not consolidate properly and the retention of previous learning (A) is compromised. Memory interference is a useful experimental tool to investigate memory formation processes because it allows to test the strength of a memory trace during its consolidation, however, its underlying mechanisms are not well understood. The short term objective of my research program is to conduct 4 studies that use memory interference paradigms applied through behavioural and non-invasive brain stimulation techniques to discover neurophysiological mechanisms underlying memory interference in the context of healthy aging. Study 1 explores if the coupling between cortico-spinal neurons changes as a result of retrograde and anterograde interference. Study 2 investigates if the susceptibility to interference of the primary motor cortex signals the pace of memory consolidation. Study 3 explores if the inhibition of brain networks involved in processing different types of memory modifies the susceptibility to interference between different memory systems. Study 4 investigates if long term potentiation, a substrate of memory formation, predicts interference. The long term goal of my research program is to create a novel framework to explain memory interference. This framework argues that interference arises as the competition for neural networks and resources between the primary (A) and interfering tasks (B). When no overlap between memory representations exists and 2 independent neuronal pools are elicited, both memory traces can be consolidated in parallel and interference does not occur. In contrast, when consolidation requires the same pool of synapses, interference occurs.