Autoscopic Experiences (AE, OBE)

The Abnormal Body Perception (Autoscopy/OBE)

Disembodiment phenomena due to altered body perception (ABP) and regrouping autoscopy (AS) and out-of-body experiences (OBE/180° body reversal), the common view sustains that the temporoparietal junction (TPJ), especially the right hemisphere, is the neural hub to convey multisensory body-related information and builds a coherent sense of body ownership (Blanke et al., 2002). Indeed, multisensory conflicts seem to be the cornerstone of abormal body perception (Ionta et al,. 2011) and phenomenological changes in perceived body ownership seem to follow the progressive stimulation of right TPJ (Blanke, 2000). However, further investigations reported controversial evidence. On the one hand, also the left TPJ seems to be involved in disembodiment (Bos et al., 2016). On the other hand, TPJ is not the only brain region implied in body ownership since, for instance, abnormal body perceptions have been associated with the medial occipitoparietal junction (Jonas et al., 2014), occipital cortex (Daltrozzo et al., 2016), precuneus/thalamus (Dirk et al., 2007), and thalamo-occipital radiations (Smith & Messier., 2014). This large synchronous functional network is known to be involved in reflective self-awareness (Kjaer et al., 2002). Interestingly, the activation process of the funtional network never lead to disembodiment but only to autoscopy (without large changes in visuoperspective and location).
To summarize, a deactivation/desynchronization process along a highly functional network might be linked to OBE (Daltrozzo et al., 2016). In sum, the specificity of the rTPJ for ABP is controversial and a systematic decrease of EEG power is found in all frequency bands, suggesting that a cortical deactivation/desynchronization (possible reduced connectivity) is correlated with ABP. One possible reason of this inconsistency is that most of the previous studies (1) were focused on only one TPJ (left or right) and (2) did not include the analysis of global brain dynamics following the manipulation of neural activity in TPJ.

Scientific Papers on Autoscopic Phenomena (AE, OBE)

Arzy, S., Overney, L. S., Landis, T., & Blanke, O. (2006). Neural Mechanisms of Embodiment: Asomatognosia Due to Premotor Cortex Damage. Archives of Neurology, 63(7), 1022. https://doi.org/10.1001/archneur.63.7.1022

Blanke, O. (2000). Simple and complex vestibular responses induced by electrical cortical stimulation of the parietal cortex in humans. Journal of Neurology, Neurosurgery & Psychiatry, 69(4), 553–556. https://doi.org/10.1136/jnnp.69.4.553

Blanke, O., & Arzy, S. (2005). The Out-of-Body Experience: Disturbed Self-Processing at the Temporo-Parietal Junction. The Neuroscientist, 11(1), 16–24. https://doi.org/10.1177/1073858404270885

Blanke, O., & Dieguez, S. (2009). Leaving Body and Life Behind: Out-of-Body and Near-Death Experience. In The Neurology of Consciousness (pp. 303–325). Elsevier. https://doi.org/10.1016/B978-0-12-374168-4.00023-X

Blanke, O., Landis, T., Spinelli, L., & Seeck, M. (2004). Out‐of‐body experience and autoscopy of neurological origin. Brain, 127(2), 243–258. https://doi.org/10.1093/brain/awh040

Blanke, O., Mohr, C., Michel, C. M., Pascual-Leone, A., Brugger, P., Seeck, M., Landis, T., & Thut, G. (2005). Linking Out-of-Body Experience and Self Processing to Mental Own-Body Imagery at the Temporoparietal Junction. The Journal of Neuroscience, 25(3), 550–557. https://doi.org/10.1523/JNEUROSCI.2612-04.2005

Blanke, O., Ortigue, S., Landis, T., & Seeck, M. (2002). Stimulating illusory own-body perceptions. Nature, 419(6904), 269–270. https://doi.org/10.1038/419269a

Bos, E. M., Spoor, J. K. H., Smits, M., Schouten, J. W., & Vincent, A. J. P. E. (2016). Out-of-Body Experience During Awake Craniotomy. World Neurosurgery, 92, 586.e9-586.e13. https://doi.org/10.1016/j.wneu.2016.05.002

Daltrozzo, J., Kotchoubey, B., Gueler, F., & Karim, A. A. (2016). Effects of Transcranial Magnetic Stimulation on Body Perception: No Evidence for Specificity of the Right Temporo-Parietal Junction. Brain Topography, 29(5), 704–715. https://doi.org/10.1007/s10548-016-0496-0

Dirk, D. R., Koen, V. L., Patrick, D., & Tomas, M. (2007). Visualizing Out-of-Body Experience in the Brain. The New England Journal of Medicine.

Ehrsson, H. H. (2007). The Experimental Induction of Out-of-Body Experiences. Science, 317(5841), 1048–1048. https://doi.org/10.1126/science.1142175

Ionta, S., Heydrich, L., Lenggenhager, B., Mouthon, M., Fornari, E., Chapuis, D., Gassert, R., & Blanke, O. (2011). Multisensory Mechanisms in Temporo-Parietal Cortex Support Self-Location and First-Person Perspective. Neuron, 70(2), 363–374. https://doi.org/10.1016/j.neuron.2011.03.009

Jonas, J., Maillard, L., Frismand, S., Colnat-Coulbois, S., Vespignani, H., Rossion, B., & Vignal, J.-P. (2014). Self-face hallucination evoked by electrical stimulation of the human brain. Neurology, 83(4), 336–338. https://doi.org/10.1212/WNL.0000000000000628

Kheradmand, A., Lasker, A., & Zee, D. S. (2015). Transcranial Magnetic Stimulation (TMS) of the Supramarginal Gyrus: A Window to Perception of Upright. Cerebral Cortex, 25(3), 765–771. https://doi.org/10.1093/cercor/bht267

Kjaer, T. W., Nowak, M., & Lou, H. C. (2002). Reflective Self-Awareness and Conscious States: PET Evidence for a Common Midline Parietofrontal Core. NeuroImage, 17(2), 1080–1086. https://doi.org/10.1006/nimg.2002.1230

Lenggenhager, B., Tadi, T., Metzinger, T., & Blanke, O. (2007). Video Ergo Sum: Manipulating Bodily Self-Consciousness. Science, 317(5841), 1096–1099. https://doi.org/10.1126/science.1143439

Longo, M. R., Schüür, F., Kammers, M. P. M., Tsakiris, M., & Haggard, P. (2008). What is embodiment? A psychometric approach. Cognition, 107(3), 978–998. https://doi.org/10.1016/j.cognition.2007.12.004

Mantovani, A., Simeon, D., Urban, N., Bulow, P., Allart, A., & Lisanby, S. (2011). Temporo-parietal junction stimulation in the treatment of depersonalization disorder. Psychiatry Research, 186(1), 138–140. https://doi.org/10.1016/j.psychres.2010.08.022

Nakul, E., & Lopez, C. (2017). Commentary: Out-of-Body Experience during Awake Craniotomy. Frontiers in Human Neuroscience, 11, 417. https://doi.org/10.3389/fnhum.2017.00417

Northoff, G., & Bermpohl, F. (2004). Cortical midline structures and the self. Trends in Cognitive Sciences, 8(3), 102–107. https://doi.org/10.1016/j.tics.2004.01.004

Smith, A. M., & Messier, C. (2014). Voluntary Out-of-Body Experience: An fMRI Study. Frontiers in Human Neuroscience, 8. https://doi.org/10.3389/fnhum.2014.00070

Tsakiris, M., Hesse, M. D., Boy, C., Haggard, P., & Fink, G. R. (2007). Neural Signatures of Body Ownership: A Sensory Network for Bodily Self-Consciousness. Cerebral Cortex, 17(10), 2235–2244. https://doi.org/10.1093/cercor/bhl131

How to investigate AE, OBE with scientific tools ?

In order to understand the causal role of TPJ in self-bodily awareness and the associated modified neural dynamics (desynchronization hypothesis), the experimental protocol encompasses a phenomenological inquiry (embodiment scales) before and after the rTMS-induced inhibition of bilateral TPJs in order to understand the phenomenological within- and between-subject effects with regard to experimental conditions (inhibition, sham).

The combined EEG analyses will allow to pinpoint the variations of EEG power and delimitate the possible correlations between TMS-induced abnormal body perception and cortical deactivation (desynchronization) across the scalp.