Thirioux Bérangère, Wehrmann Moritz, Langbour Nicolas, Jaafari Nematollah, Berthoz Alain
Laboratoire de Physiologie de la Perception et de l'Action UMR 7152 CNRS, Collège de FranceParis, France; Unité de Recherche Clinique Intersectorielle en Psychiatrie à vocation régionale Pierre Deniker, Centre Hospitalier Henri LaboritPoitiers, France.
Laboratoire de Physiologie de la Perception et de l'Action UMR 7152 CNRS, Collège de FranceParis, France; Bauhaus-Universität WeimarWeimar, Germany.
Front Psychol. 2016 Aug 25;7:1283. doi: 10.3389/fpsyg.2016.01283. eCollection 2016.
Looking at our face in a mirror is one of the strongest phenomenological experiences of the Self in which we need to identify the face as reflected in the mirror as belonging to us. Recent behavioral and neuroimaging studies reported that self-face identification not only relies upon visual-mnemonic representation of one's own face but also upon continuous updating and integration of visuo-tactile signals. Therefore, bodily self-consciousness plays a major role in self-face identification, with respect to interplay between unisensory and multisensory processing. However, if previous studies demonstrated that the integration of multisensory body-related signals contributes to the visual processing of one's own face, there is so far no data regarding how self-face identification, inversely, contributes to bodily self-consciousness. In the present study, we tested whether self-other face identification impacts either the egocentered or heterocentered visuo-spatial mechanisms that are core processes of bodily self-consciousness and sustain self-other distinction. For that, we developed a new paradigm, named "Double Mirror." This paradigm, consisting of a semi-transparent double mirror and computer-controlled Light Emitting Diodes, elicits self-other face merging illusory effect in ecologically more valid conditions, i.e., when participants are physically facing each other and interacting. Self-face identification was manipulated by exposing pairs of participants to an Interpersonal Visual Stimulation in which the reflection of their faces merged in the mirror. Participants simultaneously performed visuo-spatial and mental own-body transformation tasks centered on their own face (egocentered) or the face of their partner (heterocentered) in the pre- and post-stimulation phase. We show that self-other face identification altered the egocentered visuo-spatial mechanisms. Heterocentered coding was preserved. Our data suggest that changes in self-face identification induced a bottom-up conflict between the current visual representation and the stored mnemonic representation of one's own face which, in turn, top-down impacted bodily self-consciousness.
照镜子看自己的脸是自我最强烈的现象学体验之一，在这个过程中，我们需要将镜子中反射出的脸识别为属于自己的脸。最近的行为和神经影像学研究表明，自我面部识别不仅依赖于对自己面部的视觉记忆表征，还依赖于视觉触觉信号的持续更新和整合。因此，就单感官和多感官处理之间的相互作用而言，身体自我意识在自我面部识别中起着重要作用。然而，尽管先前的研究表明，与身体相关的多感官信号的整合有助于对自己面部的视觉处理，但迄今为止，尚无关于自我面部识别如何反过来影响身体自我意识的数据。在本研究中，我们测试了自我与他人面部识别是否会影响以自我为中心或以外界为中心的视觉空间机制，这些机制是身体自我意识的核心过程，并维持自我与他人的区分。为此，我们开发了一种新的范式，名为“双镜”。这种范式由一个半透明的双镜和计算机控制的发光二极管组成，在更符合生态效度的条件下，即当参与者面对面互动时，会引发自我与他人面部融合的错觉效应。通过让参与者 pairs 接受人际视觉刺激，其中他们的面部反射在镜子中融合，来操纵自我面部识别。在刺激前和刺激后阶段，参与者同时执行以自己的脸（以自我为中心）或其伙伴的脸（以外界为中心）为中心的视觉空间和心理自我身体转换任务。我们发现，自我与他人面部识别改变了以自我为中心的视觉空间机制。以外界为中心的编码得以保留。我们的数据表明，自我面部识别的变化在当前视觉表征与自己面部的存储记忆表征之间引发了自下而上的冲突，进而自上而下地影响了身体自我意识。
