Jacobs R, van Steenberghe D, Schotte A
Department of Periodontology, Faculty of Medicine, Catholic University, Leuven, Belgium.
Arch Oral Biol. 1992 Sep;37(9):677-83. doi: 10.1016/0003-9969(92)90071-f.
The anatomical position of the mandible means that direct visual feedback is not possible. To clarify the role of visual information, several jaw- and finger-positioning tasks were designed, both in a 'free-movement' and an 'isolated' (arm or head fixed) state, with or without a visual feedback display of the target position. The subjects had to position the mandible or the index finger of the preferred hand on to a movable metal bar and to maintain a defined position coinciding with the target level provided on an oscilloscope screen. The position signal was tape recorded and computer analysed off-line. Digital filtering differentiated between the drift and the oscillations around the target (root mean square). The results demonstrated a lack of precision in the free-movement, finger-positioning task after withdrawal of visual feedback. For jaw opening and closing muscles, position control was less impaired when a visual feedback display was abolished. It was suggested that the efficiency of jaw positioning is not primarily determined by visual feedback.
下颌骨的解剖位置意味着无法获得直接的视觉反馈。为了阐明视觉信息的作用，设计了几种下颌和手指定位任务，包括“自由运动”和“孤立”（手臂或头部固定）状态，有或没有目标位置的视觉反馈显示。受试者必须将下颌或优势手的食指放在可移动的金属棒上，并保持与示波器屏幕上提供的目标水平一致的特定位置。位置信号被磁带记录并离线进行计算机分析。数字滤波区分了围绕目标的漂移和振荡（均方根）。结果表明，在撤回视觉反馈后，自由运动的手指定位任务缺乏精确性。对于下颌开合肌肉，取消视觉反馈显示时，位置控制受到的损害较小。研究表明，下颌定位的效率并非主要由视觉反馈决定。
