MEi:CogSci Conferences, MEi:CogSci Conference 2010, Dubrovnik

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OUT OF BODY EXPERIENCE
Sasko Djurasevic

Last modified: 2010-06-14

Abstract


Introduction
The objective of this paper is to propose a method to be used for the experimental research of OBE.Studies in the field of OBE have developed and reached new dimensions in the past years.
First I limit the term OBE (Out of Body Experience) , which relates to experience where a person seems to be awake and sees his physical body and environment from a location out and away from his physical body. I will also investigate the methods and lesions which may trigger such sensation. In Neuroscience the OBE is seen as a result of transient failure to integrate the visual, tactile, proprioperceptive and vestibular information with sensory information of extrapersonal space, that converges at the temporoparietal junction, especially in the right hemisphere. Partly disintegration can be induced by stimulating angular - supramarginal junction, which suggests the involvement of investibular somatosenzory integration of body orientation in space. In regard to a brain lesion the OBE is often experienced among patients with epilepsy.

Methods
There are several methods developed to evoke and investigate OBE. Induced OBE experience is evoked with electrical stimulation (implanted electrodes) of the brain's right hemisphere at temporoparietal junction. TMS (Transcranial Magnetic Stimulation uses magnetic fields to stimulate nerve cells in the brain. Among the fast developing new techniques is a noninvasive method which uses virtual reality goggles to mix up the sensory signals reaching the brain. In one experiment Ehrsson and Blanke (source: 24 August 2007 issue of Science) used video cameras and virtual reality goggles to show volunteers images of their own bodies from the perspective of someone behind them. Virtual reality systems may provide further answers to scientific explanation related to distorted full-body perception. Devices used to measure the brain activities during OBE induced experience are mainly EEG, PET and fMRI. Additional measurements involve changes of skin impedance, skin temperature, sudden changes in subtle magnetic field and temperature in the near environment.

Proposal
The most promising and affordable method would be a type of virtual reality systems as presented by Blanke (Brain 2004, p. 243-258). The basic will be the controlled room where we are going to use the system which projects images of a person in a space in front of physical body. We will experiment with one or multiple projected virtual bodies, partly covered or missing and in different positions, touching the volunteers' bodies, both physically and virtually. We shall also investigate OBE in relation to failures to integrate full body perception. OBE results will be reported by the volunteers involved in experiments, by recording the EEG signals in specific regions near and around temporoparietal junctions and by recording the changes in ELF magnetic fields and temperature around a person involved in the experiment. In additional study we shall use Shakti helmet to evoke and speed up OBE experience, by stimulating angular-supramarginal junctions of the right hemisphere to induce different body perceptions and states of consciousness.

Sources:
1. Shahar Arzy, Gregor Thut, Christine Mohr, Christoph M. Michel, Olaf Blanke: August 2, 2006 Neural Basis of Embodiment: Distinct Contributions of Temporoparietal Junction and Extrastriate Body Area, The Journal of Neuroscience, o 26(31):8074-8081
2. Olaf Blanke, Theodor Landis, Laurent Spinelli and Margitta Seeck: 2004 Out-of-body experience and autoscopy of neurological origin Brain , 127, 243 ? 258