Perceptual distortions of the human body image produced by local anaesthesia, pain and cutaneous stimulation
Perceptual distortions of the human body image produced by local anaesthesia, pain and cutaneous stimulation
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DOI：
10.1111/j.1469-7793.1999.609ae.x
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发表时间：
1999-01-15
影响因子：
5.5
通讯作者：
Phegan, CML
中科院分区：
文献类型：
--
作者：
Gandevia, SC;Phegan, CML
1.如果要在空间中准确地移动手，了解手的大小和方向是必不可少的。我们使用了两种心理物理学方法来确定当感觉输入改变时，身体部位的感知大小是否会改变：第一，选择与身体部位的表观大小相匹配的缩放绘图，第二，运动任务，其中受试者绘制身体部位以描绘其感知大小。完全麻醉的拇指（与手指神经阻滞）显着增加了60-70%的感知大小时，评估与心理物理方法。在麻醉期间，对侧相邻食指或手指的感知大小不变。然而，未麻醉的嘴唇的大小增加（接近50%）。当用两种测量方法进行评估时，嘴唇的明显感觉丧失（由局部麻醉剂产生）显着增加了它们的感知大小。拇指的表观尺寸略有增加。为了确定感知尺寸的变化是否也可以由外周输入的升高产生，使用了对指神经的无害电刺激以及对手指的疼痛冷却。这两个程序产生的刺激部分的感知大小的小，但显着的增加。结果突出了身体各部分感知大小的不稳定性，以及这如何影响运动输出。这些数据可能会揭示知觉的后果，急性变化的中枢体感地图，这些变化是已知的传入神经阻滞发生。
1. Knowledge of the size and orientation of the hand is essential if it is to be moved accurately in space. We used two psychophysical methods to determine whether the perceived size of a body part changes when its sensory input is changed: first, the selection of scaled drawings which matched the apparent size of a body part, and second, a motor task in which the subject drew the body part to depict its perceived size.2. Complete anaesthesia of the thumb (with a digital nerve block) significantly increased its perceived size by 60-70% when assessed with both psychophysical methods. During this anaesthesia, the perceived size of the adjacent index finger or digits on the contralateral side was unaltered. However, the size of the unanaesthetized lips increased (by similar to 50 %).3. Marked sensory loss for the lips (produced by topical anaesthetics) significantly increased their perceived size when assessed with both methods of measurement. There was a small increase in apparent size of the thumb.4. To determine whether changes in perceived size could also be produced by an elevation of peripheral inputs, innocuous electrical stimulation of the digital nerves and also painful cooling of the digit were used. Both procedures produced small but significant increases in perceived size of the stimulated part.5. The results highlight lability in the perceived size of parts of the body and how this affects motor output. The data may reveal perceptual consequences of acute changes in central somatosensory maps, changes which are known to occur with deafferentation.