The full body illusion (FBI) is a bodily illusion based on the application of multisensory conflicts that induce changes in bodily self-consciousness (BSC). This has been used to study cognitive brain mechanisms underlying body ownership and related aspects of self-consciousness. Typically, such paradigms employ external passive multisensory stimulation, thus neglecting the possible contributions of self-generated action and haptic cues to body ownership. In this article, the effects of both external and voluntary self-touch on BSC were examined with a robotics-based FBI paradigm. We compared the effects of classical passive visuotactile stimulation and active self-touch (in which experimental participants had a sense of agency over the tactile stimulation) on the FBI. We evaluated these effects using a questionnaire, crossmodal congruency task, and measurements of changes in self-location. The results indicated that both synchronous passive visuotactile stimulation and synchronous active self-touch induced illusory ownership over a virtual body, without significant differences in their magnitudes. However, the FBI induced by active self-touch was associated with a larger drift in self-location towards the virtual body. These results show that movement-related signals arising from self-touch impact the BSC not only for hand ownership but also for torso-centered body ownership and related aspects of BSC.

中文翻译：

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通过自我和外部接触调节身体自我意识

全身错觉 (FBI) 是一种基于应用引起身体自我意识 (BSC) 变化的多感官冲突的身体错觉。这已被用于研究身体所有权和自我意识相关方面的认知大脑机制。通常，这种范式采用外部被动多感官刺激，从而忽略了自我生成的动作和触觉提示对身体所有权的可能贡献。在本文中，使用基于机器人的 FBI 范式检查了外部和自愿自我接触对 BSC 的影响。我们比较了经典被动视觉触觉刺激和主动自我触摸（实验参与者对触觉刺激有一种代理感）对 FBI 的影响。我们使用问卷、跨模态一致性任务评估了这些效果，以及自我定位变化的测量。结果表明，同步被动视觉刺激和同步主动自我触摸都会引起对虚拟身体的幻觉所有权，它们的大小没有显着差异。然而，主动自我触摸引起的 FBI 与自我定位向虚拟身体的较大漂移有关。这些结果表明，自我触摸产生的运动相关信号不仅会影响 BSC 的手所有权，还会影响以躯干为中心的身体所有权和 BSC 的相关方面。由主动自我触摸引起的 FBI 与自我定位向虚拟身体的较大漂移有关。这些结果表明，自我触摸产生的运动相关信号不仅会影响 BSC 的手所有权，还会影响以躯干为中心的身体所有权和 BSC 的相关方面。由主动自我触摸引起的 FBI 与自我定位向虚拟身体的较大漂移有关。这些结果表明，自我触摸产生的运动相关信号不仅会影响 BSC 的手所有权，还会影响以躯干为中心的身体所有权和 BSC 的相关方面。