RESUMEN
A historical review of the concepts of self-consciousness is presented, highlighting the important role of the body (particularly, body perception but also body action), and the social other in the construction of self-consciousness. More precisely, body perception, especially intermodal sensory perception including kinesthetic perception, is involved in the construction of a sense of self allowing self-other differentiation. Furthermore, the social other, through very early social and emotional interactions, provides meaning to the infant's perception and contributes to the development of his/her symbolization capacities. This is a necessary condition for body image representation and awareness of a permanent self in a time-space continuum (invariant over time and space). Self-image recognition impairments in the mirror are also discussed regarding a comprehensive developmental theory of self-consciousness. Then, a neuropsychological and neurophysiological approach to self-consciousness reviews the role of complex brain activation/integration pathways and the mirror neuron system in self-consciousness. Finally, this article offers new perspectives on self-consciousness evaluation using a double mirror paradigm to study self- and other- image and body recognition.
RESUMEN
Clinical observations suggest early self-consciousness disturbances in schizophrenia. A double mirror combining the images of two individuals sitting on each side of the mirror was used to study self-other differentiation in 12 individuals with early onset schizophrenia (EOS) and 15 individuals with adult onset schizophrenia (AOS) compared to 27 typically developing controls (TDC) matched on age and sex. The effects of intermodal sensory perception (visual-tactile and visual-kinesthetic) on self-other recognition were also studied. The results showed that EOS and AOS individuals, independently of age and schizophrenia severity, were centered on their own image compared to TDC, with both significant earlier self-recognition and delayed other-recognition during the visual recognition task. In addition, there was no significant effect of intermodal sensory stimulation on self-other recognition in EOS and AOS patients, whereas self-centered functioning was significantly increased by visual-tactile stimulation and decreased by visual-kinesthetic stimulation in TDC. The findings suggest that self-other recognition impairments might be a possible endophenotypic trait of schizophrenia.
RESUMEN
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.
