Motor memory interference

运动学习是通过运动练习提高运动技能的过程。练习对于学习运动技能是必不可少的，因为神经系统正是在练习的过程中编码用于阐述运动记忆的感觉运动信息。然而，神经系统不会随着练习的结束而停止处理信息。在练习一项运动任务(A)后，在练习中编码的信息作为一种运动记忆形式在大脑中得到巩固。如果巩固成功，在练习A的过程中编码的记忆变得更稳定，导致A的保留，甚至在不需要额外训练的情况下，在练习之间进一步提高技能表现。然而，在巩固的初始阶段，运动记忆仍然是脆弱的，如果在不久之后练习第二个运动任务(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：逆行干扰和顺行干扰。当练习B打乱A的巩固时发生逆行干扰，当练习B损害A在保留时的表现时发生顺行干扰。当干扰发生时，记忆不能正确地巩固，对先前学习(A)的保留受到损害。记忆干扰是研究记忆形成过程的一种有用的实验工具，因为它允许测试记忆痕迹在巩固过程中的强度，然而，其潜在的机制尚未被很好地理解。我的研究计划的短期目标是进行4项研究，使用通过行为和非侵入性脑刺激技术应用的记忆干扰范式，以发现健康老龄化背景下潜在的记忆干扰的神经生理机制。研究1探索皮质-脊髓神经元之间的耦合是否由于逆行和顺行干扰而改变。研究2调查初级运动皮质对干扰的敏感性是否标志着记忆巩固的速度。研究3探索了参与处理不同类型记忆的大脑网络的抑制是否改变了对不同记忆系统之间干扰的敏感性。研究4调查记忆形成的底物--长时程增强是否能预测干扰。

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.