•Octopus suckers have a strong tendency to attach to any substrate they contact
•This raises the question of why octopus arms do not grab or interfere with each other
•Here it is shown that chemical signals from octopus skin inhibit the attachment reflex
•Thus, constraining the arms from interfering with each other simplifies motor control
由于自身足腕几乎无限自由度，控制这些柔性足腕的运动对章鱼来说变成了一项艰巨的任务。 而章鱼则运用能降低自由度的刻板运动模式简化了这种控制，将足腕在可操控环境下控制在了几条。 这些运动由大脑触发并由嵌入在足腕外周神经肌肉系统中的运动程序所产生。每条足腕上的数百吸盘倾向于吸附他们能接触的任何物体。假如没有适当管理则这种反射的存在可能会造成足腕间相互干扰的显著问题。并且由于章鱼“无法辨别自身足腕”，这一问题更显严重。我们在此表明了在自动控制中十分重要的自我识别机制， 它能抑制足腕间的相互干扰。我们展示了已截断足腕的吸盘从来不会吸附章鱼皮肤， 因为在皮肤上的化学物质抑制了吸盘的吸附反射。 这一外设机制似乎能受中央控制操控，因为与截断足腕行为不同的是章鱼有时会抓取截肢。出人意料的是章鱼似乎能识别自身已截断的足腕，因为他们常常只会将别人的足腕而不是自己的足腕当作食物。这种自我识别机制是章鱼大脑，身体和环境之间的适应性交互作用表征管理中的新颖的外部组成。
Controlling movements of flexible arms is a challenging task for the octopus because of the virtually infinite number of degrees of freedom (DOFs). Octopuses simplify this control by using stereotypical motion patterns that reduce the DOFs, in the control space, to a workable few. These movements are triggered by the brain and are generated by motor programs embedded in the peripheral neuromuscular system of the arm. The hundreds of suckers along each arm have a tendency to stick to almost any object they contact. The existence of this reflex could pose significant problems with unplanned interactions between the arms if not appropriately managed. This problem is likely to be accentuated because it is accepted that octopuses are “not aware of their arms”. Here we report of a self-recognition mechanism that has a novel role in motor control, restraining the arms from interfering with each other. We show that the suckers of amputated arms never attach to octopus skin because a chemical in the skin inhibits the attachment reflex of the suckers. The peripheral mechanism appears to be overridden by central control because, in contrast to amputated arms, behaving octopuses sometime grab amputated arms. Surprisingly, octopuses seem to identify their own amputated arms, as they treat arms of other octopuses like food more often than their own. This self-recognition mechanism is a novel peripheral component in the embodied organization of the adaptive interactions between the octopus’s brain, body, and environment.