Cardio-visual full body illusion alters bodily self-consciousness and tactile processing in somatosensory cortex

Jane Aspell, Olaf Blanke, Bruno Herbelin, Lukas Heydrich
2018
Article

Résumé

Prominent theories highlight the importance of bodily perception for self-consciousness, but it is currently not known whether this is based on interoceptive or exteroceptive signals or on integrated signals from these anatomically distinct systems, nor where in the brain such integration might occur. To investigate this, we measured brain activity during the recently described 'cardio-visual full body illusion' which combines interoceptive and exteroceptive signals, by providing participants with visual exteroceptive information about their heartbeat in the form of a periodically illuminated silhouette outlining a video image of the participant's body and flashing in synchrony with their heartbeat. We found, as also reported previously, that synchronous cardio-visual signals increased self-identification with the virtual body. Here we further investigated whether experimental changes in self-consciousness during this illusion are accompanied by activity changes in somatosensory cortex by recording somatosensory evoked potentials (SEPs). We show that a late somatosensory evoked potential component (P45) reflects the illusory self-identification with a virtual body. These data demonstrate that interoceptive and exteroceptive signals can be combined to modulate activity in parietal somatosensory cortex.

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https://infoscience.epfl.ch/record/262483?ln=fr

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Jane Aspell, Olaf Blanke, Bruno Herbelin, Lukas Heydrich
2018
Article

Résumé

Official source

https://infoscience.epfl.ch/record/262483?ln=fr

À propos de ce résultat

Concepts associés (10)

La perception est l'activité par laquelle un sujet fait l'expérience d'objets ou de propriétés présents dans son environnement. Cette activité repose habituellement sur des informations fournies par

vignette|250x250px|Personnel de l'U.S. Navy utilisant un simulateur de parachute. L'expression « réalité virtuelle » (ou multimédia immersif ou réalité simulée par ordinateur) renvoie typiquement à u

La somesthésie (dite aussi sensibilité du corps) constitue un des systèmes sensoriels de l'organisme. La somesthésie désigne un ensemble de différentes sensations (pression, chaleur, douleur…) qui pr

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Turning Body and Self Inside Out. Visualized Heartbeats Alter Bodily Self-Consciousness and Tactile Perception

Jane Aspell, Olaf Blanke, Bruno Herbelin, Lukas Heydrich

Prominent theories highlight the importance of bodily perception for self-consciousness, but it is currently not known whether bodily perception is based on interoceptive or exteroceptive signals or on integrated signals from these anatomically distinct systems. In the research reported here, we combined both types of signals by surreptitiously providing participants with visual exteroceptive information about their heartbeat: A real-time video image of a periodically illuminated silhouette outlined participants’ (projected, “virtual”) bodies and flashed in synchrony with their heartbeats. We investigated whether these “cardio-visual” signals could modulate bodily self-consciousness and tactile perception. We report two main findings. First, synchronous cardio-visual signals increased self-identification with and self-location toward the virtual body, and second, they altered the perception of tactile stimuli applied to participants’ backs so that touch was mislocalized toward the virtual body. We argue that the integration of signals from the inside and the outside of the human body is a fundamental neurobiological process underlying self-consciousness.

Wiley-Blackwell2013

Chargement

What is the self? This major philosophical question has been considered too complex to be studied in neuroscience. However, during the last 20 years, researchers from different disciplines within the cognitive neurosciences have started investigating the neural correlates of self-consciousness, using a range of behavioural paradigms and functional imaging techniques. Where as many researchers have studied highorder representational aspects of self-consciousness, such as language (i.e. the use of the self-referential pronoun "I" or "Me"), converging evidence suggests that the most basic sense of self, e.g. the sensation that we possess a stable and coherent representation of our body, that we identify with our body and that we perceive the self as being located within the bodily boundaries (e.g. bodily self-consciousness), is due to integration of bodily signals from different exteroceptive sensory modalities (vision, touch, proprioception). Others have highlighted the importance signals related to internal signals (homeostasis, interoception) for self-consciousness. Using lesion analysis, we could demonstrate a causal link between damage to the right temporo-parietal junction and an altered state of bodily self-consciousness, e.g out-of-body experiences. This was confirmed using functional magnetic resonance imaging, multisensory exteroceptive conflicts and virtual reality: if healthy participants perceived themselves as "disembodied", activity in the same cortical region (i.e. temporo-parietal junction) was systematically modulated. Moreover, we were able to demonstrate in a second line of experiments that interoceptive signals can be used to systematically alter bodily self-consciousness and somatosensory processing, extending previous paradigms that focused exclusively on exteroceptive signals. This was strengthened by our finding that the left posterior insula, repeatedly linked to the representation and integration of internal and external bodily signals, is implicated in another state of altered bodily self-consciousness, e.g. heautoscopy. Our results demonstrate that bodily self-consciousness is based on a neural network that represents and integrates both external and internal signals from the body.

EPFL2012

Chargement

Distinct illusory own-body perceptions caused by damage to posterior insula and extrastriate cortex

Olaf Blanke, Lukas Heydrich

Recent research in cognitive neuroscience using virtual reality, robotic technology and brain imaging has linked self-consciousness to the processing and integration of multisensory bodily signals. This work on bodily self-consciousness has implicated the temporo-parietal, premotor and extrastriate cortex and partly originated in work on neurological patients with different disorders of bodily self-consciousness. One class of such disorders is autoscopic phenomena, which are defined as illusory own-body perceptions, during which patients experience the visual illusory reduplication of their own body in extrapersonal space. Three main forms of autoscopic phenomena have been defined. During autoscopic hallucinations, a second own body is seen without any changes in bodily self-consciousness. During out-of-body experiences, the second own body is seen from an elevated perspective and location associated with disembodiment. During heautoscopy, subjects report strong self-identification with the second own body, often associated with the experience of existing at and perceiving the world from two places at the same time. Although it has been proposed that each autoscopic phenomenon is associated with different impairments of bodily self-consciousness, past research on neurological patients and the development of experimental paradigms for the study of bodily self-consciousness has focused on out-of-body experiences and the association with temporo-parietal cortex. Here, we performed quantitative lesion analysis in the-to date-largest group of patients with autoscopic hallucination and heautoscopy and compared the location of brain damage with those of control patients suffering from complex visual hallucinations. We found that heautoscopy was associated with lesions to the left posterior insula, and that autoscopic hallucinations were associated with damage to the right occipital cortex. Autoscopic hallucination and heautoscopy were further associated with distinct symptoms and deficits. The present data suggest that the autoscopic hallucination is a visuo-somatosensory deficit implicating extrastriate cortex and is, despite the visual hallucination of the own body, not associated with major deficits in bodily self-consciousness. Based on the symptoms and deficits in patients with heautoscopy and the implication of the left posterior insula, we suggest that abnormal bodily self-consciousness during heautoscopy is caused by a breakdown of self-other discrimination regarding affective somatosensory experience due to a disintegration of visuo-somatosensory signals with emotional (and/or interoceptive) bodily signals. These brain mechanisms are distinct from those described for out-of-body experiences. The present data extend previous models of autoscopic phenomena and provide clinical evidence for the importance of emotional and interoceptive signal processing in the posterior insula in relation to bodily self-consciousness.

2013

Chargement

Distinct illusory own-body perceptions caused by damage to posterior insula and extrastriate cortex

Olaf Blanke, Lukas Heydrich

2013

EPFL2012