Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey, United States of America.
PLoS One. 2019 Feb 28;14(2):e0213265. doi: 10.1371/journal.pone.0213265. eCollection 2019.
Can the mere expectation of a sensory event being about to occur on an artificial limb be sufficient to elicit an illusory sense of ownership over said limb? This issue is currently under debate and studies using two different paradigms have presented conflicting results. Here, we employed the two relevant paradigms, namely, the magnetic touch illusion and the "tactile expectation" version of the rubber hand illusion, to clarify the role of tactile expectations in the process of attributing ownership to limbs. The illusory senses of ownership and 'magnetic touch' were quantified using questionnaires, threat-evoked skin conductance responses and a combination of motion tracking synchronized with real-time subjective ratings and skin conductance. The results showed that the magnetic touch illusion was dependent on concurrent visual and tactile stimulation and that visually induced tactile expectations alone were insufficient. Moreover, in this study, tactile expectations were not associated with the rubber hand illusion, neither in terms of subjective ratings nor skin conductance changes. Together, these findings contradict the notion that the brain uses predictions of upcoming sensory events to determine whether or not a limb belongs to the self, and, instead, emphasize the importance of correlated multisensory information.
仅仅预期一个感觉事件即将发生在人工肢体上，是否足以引起对该肢体的虚幻所有权感？这个问题目前存在争议，使用两种不同范式的研究得出了相互矛盾的结果。在这里，我们采用了两种相关的范式，即磁触觉错觉和橡胶手错觉的“触觉预期”版本，以阐明触觉预期在赋予肢体所有权过程中的作用。使用问卷调查、威胁引起的皮肤电导率反应以及与实时主观评分和皮肤电导率同步的运动跟踪的组合，对虚幻的所有权感和“磁触觉”进行了量化。结果表明，磁触觉错觉取决于同时的视觉和触觉刺激，仅通过视觉诱导的触觉预期是不够的。此外，在这项研究中，触觉预期与橡胶手错觉无关，无论是在主观评分还是皮肤电导率变化方面都没有关联。综上所述，这些发现与大脑使用对即将到来的感觉事件的预测来确定肢体是否属于自我的观点相矛盾，而是强调了相关多感觉信息的重要性。
