Erro Roberto, Marotta Angela, Tinazzi Michele, Frera Elena, Fiorio Mirta
Department of Neurosciences, Biomedicine and Movement Sciences, Università di Verona, Verona, Italy.
Center for Neurodegenerative Diseases (CEMAND), Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi (SA), Italy.
Sci Rep. 2018 Feb 7;8(1):2531. doi: 10.1038/s41598-018-20551-6.
When subjects look at a rubber hand being brush-stroked synchronously with their own hidden hand, they might feel a sense of ownership over the rubber hand. The perceived mislocalization of the own hand towards the rubber hand (proprioceptive drift) would reflect an implicit marker of this illusion occurring through the dominance of vision over proprioception. This account, however, contrasts with principles of multisensory integration whereby percepts result from a "statistical sum" of different sensory afferents. In this case, the most-known proprioceptive drift should be mirrored by complementary visual drift of the rubber hand in the opposite direction. We investigated this issue by designing two experiments in which subjects were not only requested to localize their own hand but also the rubber hand and further explored the subjective feeling of the illusion. In both experiments, we demonstrated a (visual) drift in the opposite direction of the proprioceptive drift, suggesting that both hands converge toward each other. This might suggest that the spatial representations of the two hands are integrated in a common percept placed in between them, contradicting previous accounts of substitution of the real hand by the rubber hand.
当受试者看着一只橡胶手与他们自己隐藏的手同时被刷动时，他们可能会对橡胶手产生一种所有权的感觉。自身手部向橡胶手的感知性位置错误定位（本体感觉漂移）将反映出这种错觉的一个隐性标志，这种错觉是通过视觉对本体感觉的主导而产生的。然而，这种解释与多感官整合的原则形成对比，在多感官整合中，感知是由不同感觉传入信息的“统计总和”产生的。在这种情况下，最著名的本体感觉漂移应该会被橡胶手在相反方向上的互补视觉漂移所反映。我们通过设计两个实验来研究这个问题，在实验中，不仅要求受试者定位他们自己的手，还要定位橡胶手，并进一步探究这种错觉的主观感受。在两个实验中，我们都证明了视觉漂移与本体感觉漂移方向相反，这表明两只手相互靠拢。这可能表明两只手的空间表征在它们之间的一个共同感知中被整合，这与之前关于橡胶手替代真实手的观点相矛盾。
