Roerdink M, Peper C E, Beek P J
Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, Vrije Universiteit, 1081BT Amsterdam, The Netherlands.
Hum Mov Sci. 2005 Jun;24(3):379-402. doi: 10.1016/j.humov.2005.06.007.
The effects of correct and transformed visual feedback on rhythmic unimanual visuo-motor tracking were examined, focusing on tracking performance (accuracy and stability) and visual search behavior. Twelve participants (reduced to 9 in the analyses) manually tracked an oscillating visual target signal in phase (by moving the hand in the same direction as the target signal) and in antiphase (by moving the hand in the opposite direction), while the frequency of the target signal was gradually increased to probe pattern stability. Besides a control condition without feedback, correct feedback (representing the actual hand movement) or mirrored feedback (representing the hand movement transformed by 180 degrees) were provided during tracking, resulting in either in-phase or antiphase visual motion of the target and feedback signal, depending on the tracking mode performed. The quality (accuracy and stability) of in-phase tracking was hardly affected by the two forms of feedback, whereas antiphase tracking clearly benefited from mirrored feedback but not from correct feedback. This finding extends previous results indicating that the performance of visuo-motor coordination tasks is aided by visual feedback manipulations resulting in coherently grouped (i.e., in-phase) visual motion structures. Further insights into visuo-motor tracking with and without feedback were garnered from the visual search patterns accompanying task performance. Smooth pursuit eye movements only occurred at lower oscillation frequencies and prevailed during in-phase tracking and when target and feedback signal moved in phase. At higher frequencies, point-of-gaze was fixated at a location that depended on the feedback provided and the resulting visual motion structures. During in-phase tracking the mirrored feedback was ignored, which explains why performance was not affected in this condition. Point-of-gaze fixations at one of the end-points were accompanied by reduced motor variability at this location, reflecting a form of visuo-motor anchoring that may support the pick up of discrete information as well as the control of hand movements to a desired location.
研究了正确和变换后的视觉反馈对有节奏的单手视觉运动跟踪的影响，重点关注跟踪性能（准确性和稳定性）以及视觉搜索行为。12名参与者（分析时减少到9名）手动跟踪一个振荡的视觉目标信号，分别进行同相跟踪（手朝与目标信号相同的方向移动）和反相跟踪（手朝与目标信号相反的方向移动），同时逐渐提高目标信号的频率以探究模式稳定性。除了无反馈的控制条件外，跟踪过程中还提供正确反馈（代表实际手部运动）或镜像反馈（代表旋转180度后的手部运动），根据执行的跟踪模式，目标和反馈信号会产生同相或反相的视觉运动。同相跟踪的质量（准确性和稳定性）几乎不受这两种反馈形式的影响，而反相跟踪明显受益于镜像反馈，而非正确反馈。这一发现扩展了先前的结果，表明视觉运动协调任务的表现得益于视觉反馈操作，从而产生连贯分组（即同相）的视觉运动结构。通过伴随任务执行的视觉搜索模式，我们进一步深入了解了有无反馈情况下的视觉运动跟踪。平滑跟踪眼动仅在较低振荡频率下出现，且在同相跟踪以及目标和反馈信号同相移动时占主导。在较高频率下，注视点固定在一个取决于所提供反馈和由此产生的视觉运动结构的位置。在同相跟踪过程中，镜像反馈被忽略，这就解释了为什么在这种情况下性能不受影响。注视点固定在端点之一时，该位置的运动变异性会降低，这反映了一种视觉运动锚定形式，可能有助于获取离散信息以及将手部运动控制到所需位置。
