Origins of submovements during pointing movements
Origins of submovements during pointing movements
复制标题
DOI：
10.1016/j.actpsy.2008.04.009
复制
发表时间：
2008-09-01
影响因子：
1.8
通讯作者：
Dounskaia, Natalia
中科院分区：
文献类型：
--
作者：
Fradet, Laetitia;Lee, Gyusling;Dounskaia, Natalia
在指向运动的最后部分经常观察到的子移动传统上被视为指向精度调整。在这里，我们通过发展证据来重新检验这一长期持续的解释，即许多亚运动可能是由电机输出变异性的各种来源引起的非校正波动。特别是，在运动终止和低速运动期间，可能会出现非矫正子运动。通过操纵运动方式(离散、反向和传球)和目标大小(小和大)，研究了这些因素和精度调节因素在分步生产中的贡献。这三种模式提供了精确度调节和运动终止的不同时间组合，从而使我们能够理清与每个因素相关的亚运动。目标大小操纵进一步强调了精确度调节的作用，并提供了移动速度的变化。根据平滑运动的扰动程度来区分粗大和细小的亚运动。研究发现，粗大的亚运动量主要与运动终止有关，而与指向精度调节无关。虽然细微的亚运动在小目标运动中比大目标运动中更常见，但其他结果表明，它们也可能不是校正的亚运动，而是归因于运动速度的降低和目标尺寸的减小而引起的运动波动。总而言之，这些发现挑战了传统的解释，表明大多数亚运动是由运动可变性的机械和神经来源产生的波动。讨论了这些发现对负责准确实现目标的机制的影响。(C)2008爱思唯尔B.V.保留所有权利。
Submovements that are frequently observed in the final portion of pointing movements have traditionally been viewed as pointing accuracy adjustments. Here we re-examine this long-lasting interpretation by developing evidence that many of submovements may be non-corrective fluctuations arising from various sources of motor output variability. In particular, non-corrective submovements may emerge during motion termination and during motion of low speed. The contribution of these factors and the factor of accuracy regulation in submovement production is investigated here by manipulating movement mode (discrete, reciprocal, and passing) and target size (small and large). The three modes provided different temporal combinations of accuracy regulation and motion termination, thus allowing us to disentangle submovements associated with each factor. The target size manipulations further emphasized the role of accuracy regulation and provided variations in movement speed. Gross and fine submovements were distinguished based on the degree of perturbation of smooth motion. It was found that gross submovements were predominantly related to motion termination and not to pointing accuracy regulation. Although fine submovements were more frequent during movements to small than to large targets, other results show that they may also be not corrective submovements but rather motion fluctuations attributed to decreases in movement speed accompanying decreases in target size. Together, the findings challenge the traditional interpretation, suggesting that the majority of submovements are fluctuations emerging from mechanical and neural Sources of motion variability. The implications of the findings for the mechanisms responsible for accurate target achievement are discussed. (C) 2008 Elsevier B.V. All rights reserved.