Department of Biology, Northeastern University Boston, MA, USA.
Front Comput Neurosci. 2013 Sep 2;7:111. doi: 10.3389/fncom.2013.00111. eCollection 2013.
Despite anecdotal reports that humans retain acquired motor skills for many years, if not a lifetime, long-term memory of motor skills has received little attention. While numerous neuroimaging studies showed practice-induced cortical plasticity, the behavioral correlates, what is retained and also what is forgotten, are little understood. This longitudinal case study on four subjects presents detailed kinematic analyses of humans practicing a bimanual polyrhythmic task over 2 months with retention tests after 6 months and, for two subjects, after 8 years. Results showed that individuals not only retained the task, but also reproduced their individual "style" of performance, even after 8 years. During practice, variables such as the two hands' frequency ratio and relative phase, changed at different rates, indicative of multiple time scales of neural processes. Frequency leakage across hands, reflecting intermanual crosstalk, attenuated at a significantly slower rate and was the only variable not maintained after 8 years. Complementing recent findings on neuroplasticity in gray and white matter, our study presents new behavioral evidence that highlights the multi-scale process of practice-induced changes and its remarkable persistence. Results suggest that motor memory may comprise not only higher-level task variables but also individual kinematic signatures.
尽管有传闻称人类可以多年甚至终身保留获得的运动技能，但运动技能的长期记忆却很少受到关注。虽然有许多神经影像学研究表明练习会引起皮质可塑性，但行为相关性，即保留了什么和遗忘了什么，还不太清楚。本研究对 4 名受试者进行了纵向案例研究，他们在 2 个月的时间里练习了双手复节奏任务，并在 6 个月后（对 2 名受试者而言，在 8 年后）进行了保留测试。结果表明，个体不仅保留了任务，而且还再现了他们个人的“风格”，即使是在 8 年后。在练习过程中，双手的频率比和相对相位等变量以不同的速度变化，这表明存在多个神经过程的时间尺度。双手之间的频率泄漏反映了手间的串扰，其衰减速度明显较慢，是仅有的在 8 年后未被保留的变量。本研究补充了最近关于灰质和白质神经可塑性的发现，提供了新的行为证据，突出了练习诱导变化的多尺度过程及其显著的持久性。研究结果表明，运动记忆可能不仅包括更高层次的任务变量，还包括个体运动学特征。
