ANALYSIS OF CEREBELLAR MOTOR DISORDERS BY VISUALLY-GUIDED ELBOW TRACKING MOVEMENT .2. CONTRIBUTION OF THE VISUAL CUES ON SLOW RAMP PURSUIT
ANALYSIS OF CEREBELLAR MOTOR DISORDERS BY VISUALLY-GUIDED ELBOW TRACKING MOVEMENT .2. CONTRIBUTION OF THE VISUAL CUES ON SLOW RAMP PURSUIT
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DOI：
10.1093/brain/110.1.1
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发表时间：
1987-02-01
期刊：
影响因子：
14.5
通讯作者：
TANAKA, R
中科院分区：
文献类型：
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作者：
BEPPU, H;NAGAOKA, M;TANAKA, R
在视觉引导的缓慢斜坡肘跟踪中，小脑共济失调患者显示出追踪速度的不规则波动，这导致与正常对照的平滑恒定速度或速率跟踪模式不同的位置跟踪模式（Beppuet al. 1984年）。这项任务提供了充分的机会，使用视觉和本体感受反馈信息来纠正错误。本研究探讨了视觉信息的作用，产生这种扫视追求模式的患者。电视屏幕被分成上下两半，每半显示一个垂直的长条。通过斜坡电压将上部条带（T，目标）从屏幕的中心水平地移动到左侧或右侧。通过连接到手柄轴的电位计，使下部条带（D，手柄的位移）与手柄的角位移成比例地移动。受试者坐在屏幕前，通过手臂控制手柄使D与T的运动相匹配。T的运动范围为手柄角运动的30度。T的速度为6.0或7.5度/秒。训练结束后，进行测试，其中DorT在追逐过程中突然从屏幕上消失。剥夺受试者关于运动肢体和/或表现的视觉信息。该程序只对对照组的表现产生轻微影响，但它显著减少了小脑性共济失调患者的速度波动，产生了更平滑的连续追踪。DorTerase任务之间的性能没有显着差异。这一结果支持了这一假设，即小脑性共济失调患者在追踪运动过程中的显著波动模式是由于重复的视觉引导纠错反应。在这个视觉慢斜坡跟踪任务的相对重要性的视觉路径传递位置信息和运动速度信息的本体感受路径进行了讨论。
In visually-guided slow ramp elbow tracking, patients with cerebellar ataxia show irregular undulations of pursuit velocity which result in a position tracking pattern unlike the smooth constant velocity or rate tracking pattern of normal controls (Beppuet al., 1984). This task provides ample opportunity to use both visual and proprioceptive feedback information for correcting errors. The present study investigated the role of visual information for generation of this saccadic pursuit pattern in the patients. A television screen was divided into upper and lower halves in each of which a vertical strip was displayed. The upper strip (T, target) was moved horizontally from the centre of the screen to the left or right by ramp voltage. The lower strip (D, displacement of the handle) was moved in proportion to angular displacement of the handle by a potentiometer coupled to the handle axis. The subject, while sitting in front of the screen, had to makeDmatch the movement ofTby controlling the handle with his arm. The range ofTmovement was 30 deg in terms of the angular movement of the handle.Tvelocity was 6.0 or 7.5 deg/s.After a training session, the test was performed in whichDorTwas suddenly erased from the screen during pursuit, depriving the subject of visual information about the moving limb and/or performance. The procedure gave only minor effects on the performance of the control subjects, but it reduced significantly the velocity undulation of the patients with cerebellar ataxia, producing a smoother continuous pursuit. There were no significant differences in performance betweenDorTerase tasks. The result supports the hypothesis that the marked undulation pattern during pursuit movement in cerebellar ataxia is due to repeated visually-guided error correction responses. The relative importance of the visual pathway for conveying position information and the proprioceptive pathway for movement velocity information in this visual slow ramp tracking task is also discussed.