■重复体感刺激(RSS)是调节初级体感皮层(S1)和初级运动皮层(M1)的神经状态的常规方法。然而,RSS对感觉运动适应中的技能获取和保留的影响仍存在争议。本研究旨在调查全手水流(WF)是否,一种独特的RSS诱导的M1去抑制,通过检验全手WF导致M1抑制的假设来影响感觉运动适应;从而,增强电机记忆保持力。
■根据运动学习前接受的预处理,将68名年轻健康参与者随机分为三组:对照组,全手水浸(WI),和全手WF。所有参与者的实验方案连续两天。在第一天(第1天),在任何预处理前进行基线经颅磁刺激(TMS)评估(T0).随后,每组接受各自的30min预处理方案.为了确定每个预处理对M1的兴奋性的影响,进行随后的TMS评估(T1)。在此之后,所有参与视觉运动跟踪任务的运动学习(ML)的参与者,其中指示他们通过调节夹紧力来使光标与目标轨迹对齐。完成ML会话后,进行最终的TMS评估(T2)。要求所有参与者在第2天的24小时后进行相同的运动学习。
■结果表明,在感觉运动适应过程中,全手WF对技能习得没有显着影响,虽然它确实减少了皮质内抑制。这种现象与S1而不是M1在感觉运动适应的早期阶段参与技能获取的想法一致。此外,技能获得后24小时的记忆保留在三组中没有显着差异,挑战我们最初的假设,即全手WF在整个感觉运动适应过程中增强记忆保持力。这可能是由于全手WF无法改变感觉运动的连接和集成,以及预处理引起的塑性反应的性质。
■总而言之,这些发现表明,尽管全手WF减弱皮质内抑制,在感觉运动适应期间,它不会调节技能获取或运动记忆保持。
UNASSIGNED: Repetitive somatosensory stimulation (RSS) is a conventional approach to modulate the neural states of both the primary somatosensory cortex (S1) and the primary motor cortex (M1). However, the impact of RSS on skill acquisition and retention in sensorimotor adaptation remains debated. This study aimed to investigate whether whole-hand water flow (WF), a unique RSS-induced M1 disinhibition, influences sensorimotor adaptation by examining the hypothesis that whole-hand WF leads to M1 disinhibition; thereby, enhancing motor memory retention.
UNASSIGNED: Sixty-eight young healthy participants were randomly allocated to three groups based on the preconditioning received before motor learning: control, whole-hand water immersion (WI), and whole-hand WF. The experimental protocol for all the participants spanned two consecutive days. On the initial day (day 1), baseline transcranial magnetic stimulation (TMS) assessments (T0) were executed before any preconditioning. Subsequently, each group underwent their respective 30 min preconditioning protocol. To ascertain the influence of each preconditioning on the excitability of the M1, subsequent TMS assessments were conducted (T1). Following this, all participants engaged in the motor learning (ML) of a visuomotor tracking task, wherein they were instructed to align a cursor with a target trajectory by modulating the pinch force. Upon completion of the ML session, final TMS assessments (T2) were conducted. All participants were required to perform the same motor learning 24 h later on day 2.
UNASSIGNED: The results revealed that whole-hand WF did not significantly influence skill acquisition during sensorimotor adaptation, although it did reduce intracortical inhibition. This phenomenon is consistent with the idea that S1, rather than M1, is involved in skill acquisition during the early stages of sensorimotor adaptation. Moreover, memory retention 24 h after skill acquisition did not differ significantly across the three groups, challenging our initial hypothesis that whole-hand WF enhances memory retention throughout sensorimotor adaptation. This could be due to the inability of whole-hand WF to alter sensorimotor connectivity and integration, as well as the nature of the plastic response elicited by the preconditioning.
UNASSIGNED: In conclusion, these findings suggest that although whole-hand WF attenuates intracortical inhibition, it does not modulate skill acquisition or motor memory retention during sensorimotor adaptation.