de Vignemont Frédérique, Majid Asifa, Jola Corinne, Haggard Patrick
Institut Jean-Nicod, EHESS-ENS-CNRS, Paris, France.
Q J Exp Psychol (Hove). 2009 Mar;62(3):500-12. doi: 10.1080/17470210802000802. Epub 2008 May 3.
How do we individuate body parts? Here, we investigated the effect of body segmentation between hand and arm in tactile and visual perception. In a first experiment, we showed that two tactile stimuli felt farther away when they were applied across the wrist than when they were applied within a single body part (palm or forearm), indicating a "category boundary effect". In the following experiments, we excluded two hypotheses, which attributed tactile segmentation to other, nontactile factors. In Experiment 2, we showed that the boundary effect does not arise from motor cues. The effect was reduced during a motor task involving flexion and extension movements of the wrist joint. Action brings body parts together into functional units, instead of pulling them apart. In Experiments 3 and 4, we showed that the effect does not arise from perceptual cues of visual discontinuities. We did not find any segmentation effect for the visual percept of the body in Experiment 3, nor for a neutral shape in Experiment 4. We suggest that the mental representation of the body is structured in categorical body parts delineated by joints, and that this categorical representation modulates tactile spatial perception.
我们如何区分身体部位？在这里，我们研究了手部和手臂之间的身体分割在触觉和视觉感知中的作用。在第一个实验中，我们发现，当两个触觉刺激施加在手腕两侧时，比施加在单个身体部位（手掌或前臂）时感觉距离更远，这表明存在“类别边界效应”。在接下来的实验中，我们排除了两种将触觉分割归因于其他非触觉因素的假设。在实验2中，我们表明边界效应并非源于运动线索。在涉及腕关节屈伸运动的运动任务中，这种效应会减弱。行动将身体部位组合成功能单元，而不是将它们分开。在实验3和实验4中，我们表明这种效应并非源于视觉不连续的感知线索。在实验3中，我们没有发现身体视觉感知的任何分割效应，在实验4中，对于一个中性形状也没有发现分割效应。我们认为，身体的心理表征是由关节划分的分类身体部位构成的，并且这种分类表征会调节触觉空间感知。
