There is growing interest in developing and using novel measures to assess how the body is represented in human infancy. Various lines of evidence with adults and older children show that tactile perception is modulated by a high-level representation of the body. For instance, the distance between two points of tactile stimulation is perceived as being greater when these points cross a joint boundary than when they are within a body part, suggesting that the representation of the body is structured with joints acting as categorical boundaries between body parts. Investigating the developmental origins of this categorical effect has been constrained by infants’ inability to verbally report on the properties of tactile stimulation. Here we made novel use of an infant brain measure, the somatosensory mismatch negativity (sMMN), to explore categorical aspects of tactile body processing in infants aged 6–7 months. Amplitude of the sMMN elicited by tactile stimuli across the wrist boundary was significantly greater than for stimuli of equal distance that were within the boundary, suggesting a categorical effect in body processing in infants. We suggest that an early-appearing, structured representation of the body into ‘parts’ may play a role in mapping correspondences between self and other.

人们越来越关注开发和使用新颖的方法来评估人体在婴儿期的代表方式。成人和大龄儿童的各种证据表明，触觉的感知是由身体的高级表征所调节的。例如，触觉刺激的两个点之间的距离被认为比它们位于身体部位内时要大，这表明它们是通过关节作为身体部位之间的分类边界而构成的。 。由于婴儿无法通过口头报告触觉刺激的特性，因此限制了这种分类作用的发展起源的研究。在这里，我们新颖地利用了婴儿脑部测量技术，即体感失配阴性（sMMN），探讨6-7个月大婴儿的触觉加工的分类方面。触觉刺激越过腕部边界引起的sMMN的幅度明显大于边界内等距刺激的幅度，表明对婴儿的身体加工有一定的分类作用。我们建议，将身体早期显示为“部分”的结构化表示形式可能在映射自我与他人之间的对应关系中起作用。