Brain-machine interfaces (BMI) allows individuals to control an external device by controlling their own brain activity, without requiring bodily or muscle movements. Performing voluntary movements is associated with the experience of agency (“sense of agency”) over those movements and their outcomes. When people voluntarily control a BMI, they should likewise experience a sense of agency. However, using a BMI to act presents several differences compared to normal movements. In particular, BMIs lack sensorimotor feedback, afford lower controllability and are associated with increased cognitive fatigue. Here, we explored how these different factors influence the sense of agency across two studies in which participants learned to control a robotic hand through motor imagery decoded online through electroencephalography. We observed that the lack of sensorimotor information when using a BMI did not appear to influence the sense of agency. We further observed that experiencing lower control over the BMI reduced the sense of agency. Finally, we observed that the better participants controlled the BMI, the greater was the appropriation of the robotic hand, as measured by body-ownership and agency scores. Results are discussed based on existing theories on the sense of agency in light of the importance of BMI technology for patients using prosthetic limbs.

脑机接口（BMI）允许个人通过控制自己的大脑活动来控制外部设备，而不需要身体或肌肉运动。进行随意运动与对这些运动及其结果的代理体验（“代理感”）相关。当人们自愿控制体重指数时，他们同样应该体验到一种代理感。然而，与正常动作相比，使用 BMI 进行动作存在一些差异。特别是，BMI缺乏感觉运动反馈，可控性较低，并且与认知疲劳增加有关。在这里，我们通过两项研究探讨了这些不同因素如何影响代理感，在这两项研究中，参与者学习通过脑电图在线解码的运动意象来控制机械手。我们观察到，使用 BMI 时缺乏感觉运动信息似乎不会影响代理感。我们进一步观察到，对 BMI 的控制力较低会降低代理感。最后，我们观察到，参与者对体重指数的控制越好，机械手的使用量就越大（通过身体所有权和代理分数来衡量）。鉴于 BMI 技术对使用假肢的患者的重要性，基于现有的代理感理论对结果进行了讨论。