The Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada.
Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.
J Neurophysiol. 2020 Nov 1;124(5):1449-1457. doi: 10.1152/jn.00271.2020. Epub 2020 Sep 30.
Many motor skills are learned with the help of instructions. In the context of complex motor sequences, instructions often break down the movement into chunks that can then be practiced in isolation. Thus, instructions shape an initial cognitive representation of the skill, which in turn guides practice. Are there ways of breaking up a motor sequence that are better than others? If participants are instructed in a way that hinders performance, how much practice does it take to overcome the influence of the instruction? To answer these questions, we used a paradigm in which participants were asked to perform finger sequences as fast and accurately as possible on a keyboard-like device. In the initial phases of training, participants had to explicitly remember and practice two- or three-digit chunks. These chunks were then combined to form seven 11-digit sequences that participants practiced for the remainder of the study. Each sequence was broken up into chunks in a way such that the instruction was either aligned or misaligned with the basic execution-level constraints. We found that misaligned chunk instruction led to an initial performance deficit compared with the aligned chunk instruction. Overall, instructions still influenced the temporal pattern of performance after 10 days of subsequent training, with shorter interpress intervals within a chunk compared with between chunks. However, for the misaligned instructed sequences, this temporal pattern was altered more rapidly, such that participants could overcome the induced performance deficit in the last week. At the end of training, participants found idiosyncratic, but interindividually stable, ways of performing each sequence. Instructions often break down motor sequences into smaller parts, such that they can be more easily remembered. Here, we show that different ways of breaking down a finger sequence can subsequently lead to better or worse performance. The initial instruction still influenced the temporal performance pattern after 10 days of practice. The results demonstrate that the initial cognitive representation of a motor skill strongly influences how a skill is learned and performed.
许多运动技能都是在指导的帮助下习得的。在复杂的运动序列中，指导通常会将运动分解成可以单独练习的小块。因此，指导形成了技能的初始认知表示，反过来又指导了练习。有没有更好的方法来分解运动序列？如果参与者受到阻碍表现的指导，需要多少练习才能克服指导的影响？为了回答这些问题，我们使用了一种范式，要求参与者在类似键盘的设备上尽可能快、尽可能准确地执行手指序列。在训练的初始阶段，参与者必须明确地记住和练习两到三位数的块。然后，这些块被组合成七个 11 位数字的序列，参与者在研究的剩余部分中练习这些序列。每个序列都被分解成块，指导方式与基本执行级别约束对齐或不对齐。我们发现，与对齐的块指导相比，不对齐的块指导会导致初始表现缺陷。总体而言，即使在随后的 10 天训练后，指导仍然会影响性能的时间模式，块内的 Press 间隔比块之间的 Press 间隔更短。然而，对于不对齐的指导序列，这种时间模式会更快地改变，以至于参与者可以在最后一周克服诱导的表现缺陷。在训练结束时，参与者找到了独特但个体间稳定的执行每个序列的方式。指导通常会将运动序列分解成更小的部分，以便更容易记住。在这里，我们表明，分解手指序列的不同方式随后会导致更好或更差的性能。初始指导在 10 天的练习后仍然会影响时间性能模式。结果表明，运动技能的初始认知表示强烈影响技能的学习和表现方式。
