Project 333607 funded under FP7-PEOPLE Marie Curie Career Integration Grant from 01/10/2013 to 30/09/2017
Principal Investigator: Dr. Christophe Lopez, CNRS
Host Institution: Centre National de la Recherche Scientifique (CNRS)
SUMMARY AND OBJECTIVES OF THE PROJECT
Multisensory processing has been proven to be of key importance for bodily experiences and the self, although research has focused mostly on the contribution of visual and somatosensory signals. The investigation of vestibular signals has received much less attention despite its key importance in coding whole-body motion and orientation in space. The BODILYSELF Project plans to investigate vestibular contributions to whole-body experiences, in particular self-location, first-person perspective taking and self-other distinction and mirroring. For this, vestibular physiology will be linked with neuroimaging and cognitive science of the self. We will use artificial stimulation of the vestibular system and multisensory conflicts – in combination with electroencephalography and fMRI – to explore the mechanisms of bodily self-consciousness. The strength and novelty of the BODILYSELF Project lies in joining approaches from cognitive neuroscience, vestibular physiology and oto-neurology, in collaboration with a philosopher of mind, for a common goal. This may lead to findings that are relevant across research fields in the cognitive neurosciences of the self, philosophy of mind, neurology and oto-neurology.
MAIN QUESTIONS AND ACHIEVEMENTS
1) Is vestibular information used for changing the viewpoint?
We combined natural vestibular stimulation on a rotatory chair with virtual reality to test how vestibular signals are processed to simulate the viewpoint of a distant avatar. While they were rotated, participants tossed a ball to a virtual character from the viewpoint of a distant avatar. Vestibular signals influence perspective taking in a direction-specific way: participants were faster when their physical body rotated in the same direction as the mental rotation needed to take the avatar’s viewpoint. In a control experiment, participants realized 3D object mental rotations, which did not involve perspective taking, during the same whole-body vestibular stimulation. Vestibular stimulation did not affect mental rotation.
In conclusion, vestibular signals have a direction-specific influence on visuo-spatial perspective taking (self-centred mental imagery), but not a general effect on mental imagery. Findings from this study suggest that vestibular signals contribute to one of the most crucial mechanisms of social cognition: understanding others’ actions.
2) Do vestibular disorders modify perspective taking?
In collaboration with the Otorhinolaryngology Department of La Conception Hospital (Prof. J.P. Lavieille, Dr. L. Bernard-Demanze) in Marseille, we evaluated the consequence of unilateral vestibular deafferentation (acoustic neurinoma) for the patient’s ability to change perspective. Our data indicate that patients with a unilateral vestibular loss are significantly slower and make more errors than age- and gender-matched healthy participants when required to simulate the viewpoint and self-location of distant avatars. This was not the case in a control visuo-spatial task requiring mental imagery (mental rotation of 3D non-human objects). This indicates that vestibular signals are involved in the mental simulation of a distant avatar’s viewpoint involving egocentric-based mental imagery. Interestingly, only patients with vestibular loss on the left side were significantly impaired with respect to the control participants. This result provides evidence for an asymmetrical contribution of the vestibular system to the sensorimotor and neural mechanisms of perspective taking.
Published abstract: Deroualle D., Borel L., Devèze A., and Lopez C. “Les Informations Vestibulaires Influencent La Prise de Perspective D’autrui : Études Chez Des Volontaires Sains et Implications Pour La Réhabilitation Vestibulaire.” Neurophysiologie Clinique/Clinical Neurophysiology 44(5), 2014: 493. doi:10.1016/j.neucli.2014.09.008.
3) Do vestibular signals contribute to social cognition?
We have reviewed several lines of evidence indicating that vestibular signals may be involved in the sensory bases of self-other distinction and mirroring, emotion perception and perspective taking.
Another article, in collaboration with Dr Caroline Falconer (University of Nottingham) and Prof Fred Mast (University of Bern) deals more specifically with how the social context influences more global self-perceptions. In this article, we outline previously overlooked areas of research to bridge the distinct field of social neuroscience with global self-perception, vestibular processing and postural control.
See the original article: Lopez, Falconer, Deroualle and Mast (2015)In the presence of others: self-location, balance control and vestibular processing. Neurophysiologie Clinique/Clinical Neurophysiology, 45: 241–254.
4) Do vestibular disorders impair bodily self-consciousness?
The consequences of vestibular disorders on balance, oculomotor control and self-motion perception have been extensively described in humans and animals. More recently, vestibular disorders have been related to cognitive deficits in spatial navigation and memory tasks. Less frequently, abnormal bodily perceptions have been described in patients with vestibular disorders. Altered forms of bodily self-consciousness include distorted body image and body schema, disembodied self-location (out-of-body experience), altered sense of agency, as well as more complex experiences of dissociation and detachment from the self (depersonalization). In this article, I suggest that vestibular disorders create sensory conflict or mismatch in multisensory brain regions, producing perceptual incoherence and abnormal body and self perceptions. This hypothesis is based on recent functional mapping of the human vestibular cortex, showing vestibular projections to the primary and secondary somatosensory cortex and in several multisensory areas found to be crucial for bodily self-consciousness.
This model was subsequently tested in a large population of patients with dizziness, in a study in collaboration with Dr Maya Elzière, an ENT specialist from the Centre des Vertiges at the Hôpital Européen in Marseille. This observational, prospective study describes otoneurological, neuropsychological and phenomenological correlates of OBE in the largest sample of patients with dizziness to date (n = 210) compared to a group of age- and gender-matched controls with no history of dizziness (n = 210). We show a significantly higher occurrence of OBE in patients with dizziness (14%) than in healthy participants (5%). Most of the patients experienced OBE only after they started having dizziness for the first time. OBE in patients with dizziness were mainly related to peripheral vestibular disorders. We also identify depersonalization-derealization, depression and anxiety as the main predictors of OBE in patients with dizziness, as well as a contribution of migraine. Depersonalization-derealization was the only significant predictor of OBE in healthy controls. Altogether, our data indicate that OBE in patients with dizziness may arise from a combination of perceptual incoherence evoked by the vestibular dysfunction with psychological factors (depersonalization-derealization, depression and anxiety) and neurological factors (migraine).
See the original article: Lopez and Elzière (2017) Out-of-body experience in vestibular disorders – a prospective study of 210 patients with dizziness. Cortex. In press. https://doi.org/10.1016/j.cortex.2017.05.026
5) What are the vestibular contributions to human self-consciousness?
Together with Dr. Bigna Lenggenhager (University of Zürich), we have contributed to an open access collection of articles edited by the German philosophers Prof. Thomas Metzinger and Dr. Jenny Windt: OPEN MIND, collecting cutting-edge articles about philosophy of mind and the cognitive neuroscience of mind, self and consciousness (see: http://open-mind.net).
See the open access article: Lenggenhager B. and Lopez C. “Vestibular Contributions to the Sense of Body, Self, and Others.” In Open MIND, edited by T. Metzinger and J. M. Windt, 1–38. Frankfurt am Main: MIND-Group, 2015.
We have confronted our opinions about vestibular perception and the vestibular contributions to self-consciousness with a philosopher of mind, Dr. Adrian Alsmith (University of Copenhagen), who is a collaborator of the BODILYSELF project.
See the open access articles: Alsmith, A. “Perspectival Structure and Vestibular Processing. A Commentary on Bigna Lenggenhager and Christophe Lopez.” In Open MIND, edited by T. Metzinger and J. M. Windt. Frankfurt am Main: MIND-Group, 2015.
6) Vestibular stimulation as a therapeutic tool for neurological and psychiatric patients?
The probable relevance of galvanic and caloric vestibular stimulations for rehabilitation of neurological and psychiatric disorders is the topic of a research article published in Current Opinion in Neurology.
7) Electrophysiological investigations of vestibular processing: electromyography and electroencephalography
We investigated how the central nervous system processes vestibular signals using non-invasive surface electromyography and scalp electroencephalography (64-channel BIOSEMI system) in healthy volunteers. State-of-the-art electrophysiological approaches, combined with experimental paradigms from social and cognitive neurosciences, should reveal the vestibular contributions to perspective taking.
See the conference proceedings:
Deroualle D., Nakul E. and Lopez C. (2016) Modulation du réflexe vestibulo-colique au cours de la prise de perspective d’autrui. Neurophysiologie Clinique/Clinical Neurophysiology, 46(4-5):254–255. doi: 10.1016/j.neucli.2016.09.044
Nakul E., Deroualle D. and Lopez C. (2016) Observing self and other body motion modulates vestibular information processing. Neurophysiologie Clinique/Clinical Neurophysiology, 46(4-5):271. doi: 10.1016/j.neucli.2016.09.085
OUTREACH ACTIVITIES AND INCREASE IN PUBLIC AWARENESS ABOUT VESTIBULAR PROCESSING AND SELF-CONSCIOUSNESS
1) Special issue in « Frontiers in Integrative Neuroscience »
Christophe Lopez (CNRS, Aix-Marseille University, France) has co-edited the Special issue « The vestibular system in cognitive and memory processes in mammals » together with Prof. Pierre Denise (Univ. Caen, France), Prof. Thomas Brandt (Univ. Munich, Germany), Prof. Paul Smith (Univ. Otago, New Zealand) and Dr. Stéphane Besnard (INSERM, Univ. Caen, France). The special issue is a collection of 24 articles written by the leading experts in the field of vestibular cognition and vestibular neuroscience.
2) « Fête de la Science » at Aix-Marseille University
Christophe Lopez, Diane Deroualle and Liliane Borel host high school students in the Laboratory of Integrative and Adaptive Neuroscience at Aix Marseille University for one day. Students are involved in experimental designs used in the research area of the BODILYSELF project, including testing the « rubber hand illusion » and the « full body illusion ».
3) Communication to non expert public in the field
Christophe Lopez presented the contribution of the vestibular organs to balance control and space perception in a public conference at La Cité des Sciences et de l’Industrie (Paris, France). The conference was followed by an hour of questions with a non expert audience, increasing public awareness about balance disorders and rehabilitation. The conference is available online here.
An article by Christophe Lopez and Olaf Blanke was published (October 2015) in a famous French public science journal (La Recherche) for a special issue on « Consciousness ».
LIST OF PUBLICATIONS FROM THE BODILYSELF PROJECT
- PAVLIDOU A., FERRE E.R., and LOPEZ C. Vestibular stimulation makes people more egocentric. In revision in Cortex. Manuscript number CORTEX-D-17-00376R1.
- LOPEZ C. Nouvelles avancées dans l’étude de la symptomatologie vestibulaire et sa prise en charge fonctionnelle. In revision in Main Libres – Physiothérapie, Ostéopathie, Thérapies Manuelles.
- NAKUL E. and LOPEZ C. (2017) Commentary: Out-of-body experience during awake Frontiers in Human Neuroscience, 11:417. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5566977/
- LOPEZ C. and ELZIERE M. (2017) Out-of-body experience in vestibular disorders – a prospective study of 210 patients with dizziness. Cortex. In press. https://doi.org/10.1016/j.cortex.2017.05.026
- DIEGUEZ S. and LOPEZ C. (2017) The bodily self: insights from clinical and experimental research. Annals of Physical and Rehabilitation Medicine, 60(3): 198–
- GALE S., PRSA M., SHURGER A., GAY A., PAILLARD A., HERBELIN B., GUYOT J.P., LOPEZ C. and BLANKE O. (2016) Oscillatory neural responses evoked by natural vestibular stimuli in humans. Journal of Neurophysiology, 115(3): 1228–1242.
- LOPEZ C. (2016) The vestibular system: balancing more than just the body. Current Opinion in Neurology, 29(1):74-83.
- LOPEZ C. (2016) Cortex vestibulaire et conscience de soi. Les Cahiers de l’Audition, Mars/Avril 2016, Vol. 29(2): 13–
- BESNARD S., LOPEZ C., BRANDT T., DENISE P. and SMITH P.F. (2015) Editorial: The vestibular system in cognitive and memory processes in mammals. Frontiers in Integrative Neuroscience, 9:55.
- LOPEZ C., FALCONER C.J., DEROUALLE D. and MAST F.W. (2015) In the presence of others: self-location, balance control and vestibular processing. Neurophysiologie Clinique/Clinical Neurophysiology, 45: 241–254.
- DEROUALLE D., BOREL L., DEVÈZE A. and LOPEZ C. (2015) Changing perspective: the role of vestibular signals. Neuropsychologia, 79: 175–185.
- LOPEZ C. (2015) Making sense of the body: the role of vestibular signals. Multisensory Research, 28(5–6): 525–557.
- LOPEZ C. and DIEGUEZ S. (2015) La représentation du corps et ses troubles: approches de la neuropsychologie et des neurosciences cognitives. In: Pérennou D., Rode G., Azouvi P. and Brun V. (Eds.). La cognition spatiale. Sauramps Médical, Montpellier, p. 63–
- LOPEZ C. and BLANKE O. (2014) Nobel Prize Centenary: Robert Bárány and the vestibular system. Current Biology, 24(21): R1026–R1028.
- FERRÈ E.R., LOPEZ C. and HAGGARD P. (2014) Anchoring the self to the body. Psychological Science, 25(11): 2106–2108.
- DEROUALLE D. and LOPEZ C. (2014) Toward a vestibular contribution to social cognition. Frontiers in Integrative Neuroscience, 8:16.
- LOPEZ C. (2013) A neuroscientific account of how vestibular disorders impair bodily self-consciousness. Frontiers in Integrative Neuroscience, 7:91.
- LOPEZ C. (2015) Vestibular cortex. In: Toga A.W. (Ed.). Brain Mapping: An Encyclopedic Reference. Volume 2: Anatomy and Physiology, Systems. Academic Press: Elsevier, p. 305–312.
- LENGGENHAGER B. and LOPEZ C. (2015) Vestibular contributions to the sense of body, self and others. In: Metzinger T. & Windt J. (Eds.). Open MIND. MIND Group, Frankfurt am Main, p. 1–38. http://open-mind.net/papers/vestibular-contributions-to-the-sense-of-body-self-and-others
- LENGGENHAGER B. and LOPEZ C. (2015) Vestibular sense and perspectival experience. A commentary on Alsmith. In: Metzinger T. & Windt J. (Eds.). Open MIND. MIND Group, Frankfurt am Main, p. 1–9. http://open-mind.net/papers/vestibular-sense-and-perspectival-experience2014a-reply-to-adrian-alsmith