Tuesday, October 27, 2009

OBEs and fantasy proneness

Several years ago I undertook some work with Dr Kathryn Gow of the Queensland University of Technology, and a number of her students. We took a look at Australian UFO abductees in respect of measures concerning fantasy proneness, paranormal beliefs and personality characteristics. The findings of our research are available to you at: http://www.anomalistik.de/gow.pdf

While conducting my recent survey of scientific journal articles on out-of-body experiences, I was pleasantly surprised to find another article by Kathryn Gow and students, but this time on OBEs. Their abstract of their paper is as follows:

Gow, K; Lang, T; Chant, D.
"Fantasy proneness, paranormal beliefs and personality features in out-of-body experiences."
Contemporary Hypnosis. 2004. 21(3):107-125.

"This study investigated the relationship between reported out-of-body experiences, certain psychological variables and personality characteristics."

"One hundred and sixty-seven participants completed a series of questionnaires to investigate differences amongst those participants reporting out-of-body experiences and those who were classified as believers or non-believers on fantasy proneness, paranormal beliefs, psychological absorption, psychological association, somatoform dissociation, certain personality characteristics and OBE experience sensations."

"The findings revealed that experients were more fantasy prone, higher in their belief in the paranormal and displayed greater somatoform dissociation."

" Psychological absorption and dissociation were higher for believers than for either experients or non-believers and in relation to experients, fantasy proneness, paranormal beliefs and the personality dimensions of institution and feeling were significantly related, as were psychological absorption, psychological dissocation and somatoform dissociation."

These kind of psychological studies are aimed at examining the differences between individuals who have experiences; whether they be OBEs or alien abductions, and others who do not.

Previous posts here, related to neurological studies of OBE experiencers, which again, are trying to determine why some persons experience OBEs and others do not.

Saturday, October 24, 2009

To sum up

(1) OBEs have been produced by electrically stimulating specific areas of the brain.
(2) OBEs are hypothesised to represent a breakdown of bodily-self sensations.
(3) OBEs have been artificially created in the laboratory by at least two different groups of researchers.

The implications of this body of work, for alien abduction accounts, is huge!

In alien abductions, individuals relate being "floated of their bed", "floated out of their car", "floated through windows and walls." Could it be that abductees never really leave their room/car and that the experience, sense of presence, figures in the bedroom; floating away etc is in fact all in the mind!

OBEs in the lab

Other 2007 work even made the headlines of the New York Times (23 August 2007). The NYT article reported upon the work of two separate groups.

Firstly, the work of Dr Olaf Blanke-a neuroscientist at Ecole Polytechnique Federale in Lausanne, Switzerland. Participants put on virtual reality goggles to view an image from a camera in the same empty room, which showed the person's back. The experimenter then stroked the participant's back with a stick, while at the same time projecting the stick's image on the illusory image of the participant's back. With synchronous strokes, participants felt their sens of self to be within the mannequin.

Secondly, the work of Dr Henrick Ehrsson, Assistant Professor, neuroscience, Karolinska Institute, Helsinki. Participants in goggles saw an image of the back of themselves from a perspective 6 feet behind them. One stick was used to stimulate the participant's chest, while another was placed under the camera's lens. Synchronous stroking produced a sense of being outside their body-located where the camera lenses were. (Ehrsson, H H. 2007. The experimental induction of out-of-body experiences. Science 317:1048.)

Another 2007 study

De Ridder, D; Van Laere, K; DuPont.P; Menovsky, T and Van de Heyning, P.
"Visualizing out-of-body experience in the brain."
The New England Journal of Medicine. 2007. 357:1829-1833.

"An out-of-body experience was repeatedly elicited during stimulation of the posterior part of the superior-temporal gyrus on the right side in a patient in whom electrodes had been implanted to suppress tinnitus. Positron-emission tomographic scanning showed brain activation at the temporoparietal junction-more specifically, at the angular - supramarginal gyrus junction and the superior temporal gyrus-sulcus on the right side. Activation was also noted at the right precuneus and posterior thalamus, extending into the superior vermis. We suggest that activation of these regions is the neural correlate of the disembodiment that is part of the out-of-body experience."

The incidence and determinants...

Terhune, D B
"The incidence and determinants of visual phenomenology during out-of-body experiences."
Cortex. 2009 Feb;45(2):236-42

"The visual content of out-of-body experiences (OBEs) has received little attention but a number of theories of OBEs include implicit predictions regarding the determinants of this phenomenological feature. Hypnagogic imagery and unusual sleep experiences, weak synaesthesia and preference for employing object and spatial visual imagic cognitive styles were psychometrically measured along with the incidence of self-reported OBEs and the absence or presence of visual content therein, in a sample of individuals from the general population. "

"Seventy percent of individuals who had experienced an OBE reported that the experience included some form of visual content. These individuals exhibited greater scores on the measures of preference for object visual imagic cognition and weak synaesthesia than those who reported an absence of visual content during their OBE."

"Subsequent analysis revealed that the measure of weak synaesthesia was the stronger discriminator of the two cohorts. The results are discussed within the context of the synaesthesia model of visual phenomenology during OBEs (Brugger 2000; Irwin 2000.)"

"This account proposes that visual content appears during these experiences through a process of cognitive dedifferentiation in which visual hallucinations are derived from available non-visual sensory cues and that such dedifferentiation is made possible through an underlying characteristic hyperconnectivity of cortical structures regulating vestibular and visual representations of the body and those responsible for the rotation of environmental objects. Predictions derived from this account and suggestions for future research are proffered."

A putative implication for ....

Easton, S; Blanke,O; Mohr, C.
"A putative implication for fronto-parietal connectivity in out-of-body experiences."
Cortex. 2009 Feb;45(2):216-27.

"Self-processing has been related to the prefrontal cortex (PFC) and the temporo-parietal junction (TPJ) as well as to their connectivity. So far, out-of-body experiences (OBEs), impressive transient deviations of intact bodily self-integration, could be associated with the TPJ, but the mediation by the frontal lobe, and thus fronto-parietal connectivity, is yet unknown. Thus we assessed switching performance to assess frontal-parietal connectivity when healthy participants (11 reported previous OBEs (OBE-individuals); 36 reported no previous OBEs (nOBE individuals)performed two different mental own body imagery tasks. By using the same stimuli of a front facing and a back-facing human figure, a cue simultaneously presented with the target indicated to participants whether they Had to take the position of the depicted human figure (disembodied self-location mimicking an OBE) or had to imagine that the figure was their own reflection in a mirror (embodied self-location)."

"By repeating trials of the same task instruction for a differing number of trials (2-6 trials) we could assess switch costs when alternating between these two task instructions with switch costs being considered to be a behavioural indicator of frontal-parietal connectivity. Results showed that OBE-individuals performed worse than nOBE-individuals in switch trials but not in trials in which the same task instruction was repeated. Moreover, this reduced performance was specific to body positions that are normally considered easier (front-facing in the mirror condition; back-facing in the OBE mimicking condition.) These findings suggest that a front-parietal network might be implicated in OBEs, and that the flexible and spontaneous egocentric perspective taking of self-congruent body representations is hampered in individuals with previous OBEs."

The body unbound:...

Cheyne, J A; Girard, T A.
"The body unbound:vestibular-motor hallucinations and out-of-body experiences."
Cortex. 2009 Feb; 45(2):201-15.

"Among the varied hallucinations associated with sleep paralysis (SP), out-of-body experiences (OBEs) and vestibular-motor (V-M) sensations represent a distinct factor. Recent studies of direct stimulation of vestibular cortex report a virtually identical set of bodily-self hallucinations. Both programs of research agree on numerous details of OBEs and V-M experiences and suggest similar hypotheses concerning their association."

"In the present study, self-report data from two on-line surveys of SP-related experiences were employed to assess hypotheses concerning the causal structure of relations among V-M experiences and OBEs during SP episodes."

"The results complement neurophysiological evidence and are consistent with the hypothesis that OBEs represent a breakdown in the normal binding of bodily-self sensations and suggest that out-of-body feelings (OBFs) are consequences of anomalous V-M experiences and precursors to a particular form of autoscopic experience, out-of-body autoscopy (OBA)."

"An additional finding was that vestibular and motor experiences make relatively independent contributions to OBE variance. Although OBEs are superficially consistent with universal dualistic and supernatural intuitions about the nature of the soul and its relation to the body, recent research increasingly offers plausible alternative naturalistic explanations of the relevant phenomenology."

The vestibular component in out-of-body experiences

Schwabe, L; Blanke, O.
"The vestibular component in out-of-body experiences:a computational approach."
Front hum Neurosci. 2008;2;17.

" Neurological evidence suggests that disturbed vestibular processing may play a key role in triggering out-of-body experiences (OBEs). Little is known about the brain mechanisms during such pathological conditions, despite recent experimental evidence that the scientific study of such experiences may facilitate the development of neurobiological models of a crucial aspect of self-consciousness: embodied self-location."

"Here we apply Bayesian modeling to vestibular processing and show that OBEs and the reported illusory changes in self-location and translation can be explained as the result of a mislead Bayesian interference, in the sense that ambiguous bottom-up signals from the vestibular otholiths in the supine body position are integrated with a top-down prior for the upright body position, which we measure during natural head movements. Our findings have relevance for self-location and translation under normal conditions and suggest novel ways to induce and study experimentally both aspects of bodily self-consciousness in healthy subjects."

Body ownership and embodiment...

Lopez, C; Halje, P; Blank, O.
Neurphysiol Clin. 2008 June; 38(3):149-161
"Body ownership and embodiment:vestibular and multisensory mechanisms."

"Body ownership and embodiment are two fundamental mechanisms of self-consciousness. The present article reviews neurological data about paroxysmal illusions during which body ownership and embodiment are affected differentially:autoscopic phenomena (out-of-body experience, heautoscopy, autoscopic hallucination, feeling of a presence) and the room tilt illusion."

"We suggest that autoscopic phenomena and room tilt illusion are related to different types of failures to integrate body-related information (vestibular, propioceptive and tactile cues) in addition to a mismatch between vestibular and visual references. In these patients, altered body ownership and embodiment has been shown to occur due to pathological activity at the temporoparietal junction and other vestibular related areas arguing for a key importance of vestibular processing. "

"We also review the possibilities of manipulating body ownership and embodiment in healthy subjects through exposition to weightlessness as well as caloric and galvanic stimulation of the peripheral vestibular apparatus. In healthy subjects, disturbed self-processing might be related to interference of vestibular stimulation with vestibular cortex leading to disintegration of bodily information and altered body ownership and embodiment. We finally propose a differential contribution of the vestibular cortical areas to the different forms of altered body ownership and embodiment."

Functional and neural mechanisms of embodiment....

Lenggenhager, B; Smith, S T; Blanke. O.
"Functional and neural mechanisms of embodiment:importance of the vestibular system and the temporal parietal junction."
Rev Neurosci. 2006; 17(6):643-57.

"Embodiment, the sense of being localized within one's physical body. is a fundamental aspect of the self. Recent research shows that self and body processing as well as embodiment require distinct brain mechanisms. Here, we review recent clinical and neuroimaging research on multisensory perception and integration as well as mental imagery, pointing out their significance for the coding of embodiment at the temporo-parietal junction (TPJ). Special reference is given to vestibular mechanisms that are relevant for self and embodiment and to methods that interfere experimentally with normal embodiment. We conclude that multisensory and vestibular coding at the TPJ mediates humans' experience as being embodied and spatially situated, and argue that pathologies concerning the disembodied self, such as out-of-body experience or autoscopic phenomena, are due to deficient multisensory integration at the TPJ."

The out-of-body experience: disturbed self-processing at the temporo-parietal junction

Blank, O; Arzy, S.
"The out-of-body experience: disturbed self-processing at the temporo-parietal junction."
Neuroscientist. 2005 Feb; 11(1);16-24.

"Folk psychology postulates a spatial unity of self and body, a "real me" that resides in one's body and is the subject of experience. The spatial unity of self and body has been challenged by various philosophical considerations but also by several phenomena, perhaps most notoriously the "out-of-body experience" (OBE) during which one's visuo-spatial perspective and one's self are experienced to have departed from their habitual position within one's body. Here the authors marshal evidence from neurology, cognitive neuroscience and neuroimaging that suggests that OBEs are related to a failure to integrate multisensory information from one's own body at the temporo-parietal junction (TPJ). It is argued that this multisensory disintegration at the TPJ leads to the disruption of several phenomenological and cognitive aspects of self-processing, causing illusory reduplication, illusory self- location, illusory perspective and illusory agency that are experienced as an OBE."

Out-of body experience, heautoscopy, and ....

Blanke, O; Mohr, C.
"Out-of-body experience, heautoscopy, and autoscopic hallucination of neurological origin implications for neurocognitive mechanisms of corporeal awareness and self-consciousness."
Brain Res Brain Res Rev. 2005 Dec 1; 50(1):184-199.

"Autoscopic phenomena (AP) are rare illusory visual experiences during which the subject has the impression of seeing a second own body in extrapersonal space. AP consist of out-of-body experience (OBE), autoscopic hallucination (AH) and heautoscopy (HAS). The present article reviews and statistically analyzes phenomenological, functional, and anatomical variables in AP of neurological origin (n=41 patients) that have been described over the last 100 years."

"This was carried out in order to further our understanding of the underlying mechanisms of AP, much as previous research into the neural bases of body part illusions has demystified these latter phenomena. Several variables could be extracted, which distinguish between or are comparable for the three AP providing testable hypotheses for subsequent research. "

"Importantly, we believe that the scientific demystification of AP may be useful for the investigation of the cognitive functions and brain regions that mediate processing of the corporeal awareness and self consciousness under normal conditions."

The out-of-body experience: precipitating factors and neural correlates

Bunning, S; Blanke, O.
The out-of-body experience:precipitating factors and neural correlates.
Prog Brain Res. 2005; 150:331-50.

"Out-of-body experiences (OBEs) are defined as experiences in which a person seems to be awake and sees his body and the world from a location outside his physical body. More precisely, they can be defined by the presence of the following three phenomenological characteristics: (1) disembodiment (location of the self outside one's body; (ii) the impression of seeing the world from an elevated and distanced visuo-spatial perspective (extracorporeal, but egocentric visuo-spatial perspective); and (iii) the impression of seeing one's own body (autoscopy) from this perspective. OBEs have fascinated mankind from time immemorial and are abundant in folklore, mythology, and spiritual experiences of most ancient and modern societies. Here we review some of the classical precipitating factors of OBEs such as sleep, drug abuse, and general anesthesis as well as their neurobiology and compare them with recent findings on neurological and neurocognitive mechanisms of OBEs."

"The reviewed data suggests that OBEs are due to functional disintegration of lower-level multisensory processing and abnormal higher-level self-processing at the temporo-parietal junction. We argue that the experimental investigation of the interactions between these multisensory and cognitive mechanisms in OBEs and related illusions in combination with neuroimaging and behavioural techniques might further our understanding of the central mechanisms of corporal awareness and self-consciousness much as previous research about the neural bases of complex body part illusions such as phantom limb has done."

Linking out-of-body expereince and self processing....

Blanke, O; Mohr, C; Michel, C M; Pascual-Leone, A; Brugger, P; Seeck, M; Landis, T; Thut, G.
Linking out-of-body experience and self processing to mental own-body imagery at the temporoparietal junction.
J Neurosci. 2005 Jan 19; 25(3):550-7.

"The spatial unity of self and body is challenged by various philosophical considerations and several phenomena, perhaps most notoriously the 'out-of-body experience' (OBE) during which one's visual perspective and one's self are experienced to have departed from their habitual position within one's body."

"Although researchers started examining isolated aspects of the self, the neurocognitive processes of OBEs have not been investigated experimentally to further our understanding of the self. With the use of evoked potential mapping, we show the selective activation of the temporoparietal junction (TPJ) at 330-400ms after stimulus onset when healthy volunteers imagined themselves in the position and visual perspective that generally are reported by people experiencing spontaneous OBEs."

"Interference with the TPJ by transcranial magnetic stimulation (TMS) at this time impaired mental transformation of one's own body in healthy volunteers relative to TMS over a control site. No such TMS effect was observed for imagined spatial transformations of external objects, suggesting the selective implication of the TPJ in mental imagery of one's own body."

"Finally, in an epileptic patient with OBEs originating from the TPJ, we show partial activation of the seizure focus during mental transformations of her body and visual perspective mimicking her OBE perceptions. These results suggest that the TPJ is a crucial structure for the conscious experience of the normal self, mediating spatial unity of self and body, and also suggests that impaired processing at the TPJ may lead to pathological selves such as OBEs."

Friday, October 23, 2009

Out-of-body experience and autoscopy of neurological origin

Blancke, O; Landis, T; Spinelli, L; Seeck, M.
Out-of-body experience and autoscopy of neurological origin
Brain. 2004 Feb; 127(Pt2):243-58.

"During an out-of-body experience (OBE), the experient seems to be awake and to see his body and the world from a location outside the physical body. A closely related experience is autoscopy (AS), which is characterized by the experience of seeing one's body in extrapersonal space. Yet, despite great public interest and many case studies, systematic neurological studies of OBE and AS are extremely rare and, to date, no testable neuroscientific theory exists. The present study describes phenomenological , neuropsychological and neuroimaging correlates of OBE and AS in six neurological patients.

"We provide neurological evidence that both experiences share important central mechanisms. We show that OBE and AS are frequently associated with pathological sensations of position, movement and perceived completeness of one's own body. These include vestibular sensations (such as floating, elevation and rotation), visual body-part illusions (such as the illusory shortening, transformation or movement of an extremity) and the experience of seeing one's body only partially during an OBE or AS. We also find that the patient's body position prior to the experience influences OBE and AS. Finally, in five patients, brain damage or brain dysfunction is localized to the temporo-parietal junction (TPJ). These results suggest that the complex experience of OBE and AS represent paroxysmal disorders of body perception and cognition (or body schema).

"The processes of body perception and cognition, and the unconscious creation of central representation (s) of one's own body based on proprioceptive, tactile, visual and vestibular information - as well as their integration with sensory information of extrapersonal space - is a prerequisite for rapid and effective action with their surroundings. Based on our findings, we speculate that ambiguous input from these different sensory systems is an important mechanism of OBE and AS, and thus the intriguing experience of seeing one's body in a position that does not coincide with its felt position.

"We suggest that OBE and AS are related to a failure to integrate proprioceptive, tactile and visual information with respect to one's own body (disintegration in personal space) and by a vestibular disfunction leading to an additional disintegration between personal (vestibular) space and extrapersonal space (visual space.)"

Stimulating illusory own-body perceptions

This is the first of the scientific journal articles about OBEs which I found on my recent web crawl.

Blanke, O; Ortique, S; Landis, T; Seeck, M.
"Stimulating illusory own-body perceptions."
Nature, 2002 Sep 19; 419(6904):269-70.

"'Out-of-body experiences (OBEs) are curious, usually brief sensations in which a person's consciousness seems to become detached from the body and take up a remote viewing position. Here we describe the repeated induction of this experience by focal electrical stimulation of the brain's right angular gyrus in a patient who was undergoing evaluation for epilepsy treatment.

" Stimulation at this site also elicited illusory transformations of the patient's arm and legs (complex somatosensory responses) and whole body displacements (vestibular responses), indicating that out-of-body experiences may reflect a failure by the brain to integrate complex somatosensory and vestibular information."

Thursday, October 22, 2009

Is it all in the mind?

I have been taking a break from this blog, in order to focus on reading some of the scientific journal articles on OBEs; which have been published since 2002.

The research presented in these articles is in sharp contrast to the material I have posted in recent times.

I have been very surprised by the volume of scientific journal articles on this topic! Suddenly, science has discovered that you can indeed study OBEs.

So, to give you, the reader, an appreciation of this new literature, I will post abstracts in a series of posts over the next couple of weeks.