Effects of kinesthetic information from body movements on accuracy in perception and cognition of object motion

我们研究了视觉和本体感觉在动态环境中估计目标位置的相对重要性。受试者完成一个位置估计任务，在这个任务中，一个目标在屏幕上以匀速水平移动，然后消失。研究结果表明，动态条件下手部本体感觉定位存在系统偏差。当没有视觉反馈时，手在跟踪运动中倾向于超过目标位置。这一特征与过去使用击打或触碰任务的研究结果大致相似。在其他实验中，如果被要求在视觉空间中估计动态手的位置，研究参与者在没有视觉反馈的情况下明显低估了他们的实际手的位移。这两种现象之间似乎有很强的联系。在这种运动任务中，超过目标位置可归因于对自己手部运动的低估，而不是对目标运动的高估。事实上，研究参与者一直低估了目标位移，即使在超调行为发生时也是如此。这些发现让我们假设，虽然人类在没有视觉的情况下有意识地意识到肢体各部分的位置变化，但大脑可能会将肢体的运动解释为肢体的远端（例如，手或指尖）相对于外部空间的移动要少得多。所以我们需要知道为什么对动态手部位置的估计偏向于认为肢体运动的程度减少了，而不是扩大了。此外，为了完成与物体相互作用的运动任务，人们如何在有意识或潜意识的水平上调整或纠正由于更多地依赖本体感觉信息而可能发生的手部运动估计错误。这些问题有待在今后的研究中进一步探讨。

We investigated the relative importance of vision and proprioception in estimating target locations in a dynamic environment. Subjects performed a position estimation task in which a target moved horizontally on a screen at a constant velocity and then disappeared. Study results indicate that proprioceptive localization of the hand included systematic biases under dynamic conditions. When visual feedback was not given, the hand tended to overshoot target positions during tracking movements. This characteristic is approximately similar to those in past studies using hitting or reaching tasks. In the other experiments, study participants significantly underestimated their actual hand displacements without visual feedback, if they were asked to estimate the dynamic hand position in visual space. There seems to be a strong relationship between these two phenomena. Overshooting the target position in such a motor task would be attributed to underestimation of own hand movements, but not overestimation of target movements. In fact, study participants consistently underestimated the target displacements, even when the overshooting behaviours took place. These findings lead us to hypothesize that while humans are consciously aware of the position change of the various parts of the limb during ongoing movement without vision, the brain might interpret the limb movement as if more distal end of the limb (e.g., hand or the tip of finger) transferred less than it actually did relative to the extrapersonal space. So we need to know why estimates of the dynamic hand position are biased toward as if the extent of limb movement is reduced, but not extended. Moreover, for attainment of a motor task interacting with an object, how do people adjust or correct, in conscious or subconscious level, errors in estimation of their hand movements that could occur as they more rely on proprioceptive information. These problems remain to be examined in future studies.