Longo Matthew R
Department of Psychological Sciences, Birkbeck, University of London London, UK.
Front Hum Neurosci. 2017 Mar 7;11:111. doi: 10.3389/fnhum.2017.00111. eCollection 2017.
Perceiving the external spatial location of touch requires that tactile information about the stimulus location on the skin be integrated with proprioceptive information about the location of the body in external space, a process called . Recent results have suggested that this process relies on a distorted representation of the hand. Here, I investigated whether similar distortions are also found on the forearm and how they are affected by the presence of the wrist joint, which forms a categorical, segmental boundary between the hand and the arm. Participants used a baton to judge the perceived location of touches applied to their left hand or forearm. Similar distortions were apparent on both body parts, with overestimation of distances in the medio-lateral axis compared to the proximo-distal axis. There was no perceptual expansion of distances that crossed the wrist boundary. However, there was increased overestimation of distances near the wrist in the medio-lateral orientation. These results replicate recent findings of a distorted representation of the hand underlying tactile spatial remapping, and show that this effect is not idiosyncratic to the hand, but also affects the forearm. These distortions may be a general characteristic of the mental representation of the arms.
感知触觉的外部空间位置需要将皮肤上刺激位置的触觉信息与身体在外部空间位置的本体感觉信息进行整合，这一过程称为 。最近的研究结果表明，这一过程依赖于手部的扭曲表征。在此，我研究了前臂是否也存在类似的扭曲，以及它们如何受到腕关节的影响，腕关节在手部和手臂之间形成了一个分类的、分段的边界。参与者使用警棍来判断施加在他们左手或前臂上的触摸的感知位置。两个身体部位都出现了类似的扭曲，与近远轴相比，中外侧轴上的距离被高估。跨越腕关节边界的距离没有感知上的扩展。然而，在中外侧方向上，靠近腕关节处的距离被高估的程度增加。这些结果重复了最近关于触觉空间重新映射背后手部扭曲表征的研究发现，并表明这种效应并非手部所特有，也会影响前臂。这些扭曲可能是手臂心理表征的一个普遍特征。
