Peripersonal space (PPS) is a multisensory representation of the space near body parts facilitating interactions with the close environment. Studies on non-human and human primates agree in showing that PPS is a body part-centered representation that guides actions. Because of these characteristics, growing confusion surrounds peripersonal and arm-reaching space (ARS), that is the space one’s arm can reach. Despite neuroanatomical evidence favoring their distinction, no study has contrasted directly their respective extent and behavioral features. Here, in five experiments (N = 140) we found that PPS differs from ARS, as evidenced both by participants’ spatial and temporal performance and by its modeling. We mapped PPS and ARS using both their respective gold standard tasks and a novel multisensory facilitation paradigm. Results show that: (1) PPS is smaller than ARS; (2) multivariate analyses of spatial patterns of multisensory facilitation predict participants’ hand locations within ARS; and (3) the multisensory facilitation map shifts isomorphically following hand positions, revealing hand-centered coding of PPS, therefore pointing to a functional similarity to the receptive fields of monkeys’ multisensory neurons. A control experiment further corroborated these results and additionally ruled out the orienting of attention as the driving mechanism for the increased multisensory facilitation near the hand. In sharp contrast, ARS mapping results in a larger spatial extent, with undistinguishable patterns across hand positions, cross-validating the conclusion that PPS and ARS are distinct spatial representations. These findings show a need for refinement of theoretical models of PPS, which is relevant to constructs as diverse as self-representation, social interpersonal distance, and motor control.

周边空间 (PPS) 是身体部位附近空间的多感官表示，有助于与近距离环境进行交互。对非人类和人类灵长类动物的研究一致表明，PPS 是一种以身体部位为中心的表示，可以指导行动。由于这些特征，围绕人际和手臂伸展空间（ARS）越来越混乱，这是一个人的手臂可以到达的空间。尽管神经解剖学证据支持它们的区别，但没有研究直接对比它们各自的程度和行为特征。这里，在五个实验中（N= 140）我们发现 PPS 与 ARS 不同，参与者的空间和时间表现及其建模都证明了这一点。我们使用 PPS 和 ARS 各自的黄金标准任务和一种新颖的多感官促进范式来绘制 PPS 和 ARS。结果表明：（1）PPS小于ARS；(2) 多感官促进空间模式的多变量分析预测参与者在 ARS 内的手部位置；(3) 多感觉促进图随着手部位置同构变化，揭示了以手为中心的 PPS 编码，因此表明与猴子多感觉神经元的感受野具有功能相似性。对照实验进一步证实了这些结果，并进一步排除了将注意力定向作为手附近多感官促进增加的驱动机制。与此形成鲜明对比的是，ARS 映射导致更大的空间范围，手部位置的模式无法区分，交叉验证了 PPS 和 ARS 是不同空间表示的结论。这些发现表明需要改进 PPS 的理论模型，这与自我表征、社会人际距离和运动控制等多种结构有关。