The Rubber Hand Illusion (RHI) is used widely to investigate the multisensory integration mechanisms that support bodily self-consciousness and, more specifically, body ownership and self-location. It has been reported that individuals affected by obesity show anomalous multisensory integration processes. We propose that these obesity-induced changes could lead to an unusual susceptibility to the RHI and anomalous bodily self-experience. To test this hypothesis, we administered a modified version of the RHI (using a picture of the participant's hand) to individuals affected by obesity and participants with a healthy weight. During synchronous and asynchronous stimulation, we compared the subjective experience of the illusion (using a questionnaire) and the effect of the illusion on self-location (i.e., proprioceptive drift). In accordance with the illusion phenomenology, both groups had a comparable subjective illusory experience after the synchronous stimulation. Nevertheless, individuals affected by obesity showed less recalibration of self-location than healthy weight participants. In light of a recent interpretation of the multisensory integration mechanisms that underpin the RHI, our findings suggest that in obesity visuo-tactile integration supporting the subjective experience of the illusion is preserved, whereas visuo-proprioceptive integration for self-location is reduced.

中文翻译：

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肥胖症中的虚拟手错觉：支持错觉体验和自我位置重新校准的多感官交互之间的分离。

橡胶手错觉 (RHI) 被广泛用于研究支持身体自我意识，更具体地说，身体所有权和自我定位的多感官整合机制。据报道，受肥胖影响的个体表现出异常的多感觉整合过程。我们认为这些肥胖引起的变化可能导致对 RHI 的异常易感性和异常的身体自我体验。为了验证这一假设，我们对受肥胖影响的个体和体重健康的参与者进行了 RHI 的修改版本（使用参与者的手的图片）。在同步和异步刺激期间，我们比较了幻觉的主观体验（使用问卷）和幻觉对自我定位的影响（即本体感觉漂移）。根据幻觉现象学，两组在同步刺激后的主观幻觉体验相当。然而，与健康体重参与者相比，受肥胖影响的个体对自我定位的重新校准较少。根据最近对支持 RHI 的多感觉整合机制的解释，我们的研究结果表明，在肥胖症中，支持幻觉主观体验的视觉触觉整合得以保留，而自我定位的视觉本体整合则减少了。