OBE (naturally occuring OBEs)
Green (1968) appealed for people who experienced OBEs to take part in her study. She recieved 400 participants and she developed a classification system for different types of OBEs. 20% of the voulenteers had experienced a parasomatic body (another body), this tended to be a exact replica of themselves or a wieghtless cloud. Some had a asomatic OBE (no sense of another body). 3.5% of cases had a cord connecting the 2 bodies together. Green also discovered that 25% of OBEs occured due to stress, 12% during sleep.
OBEs are incredibly hard to study beacuse they are unpredictable. Any study on OBEs are based on descriptions given by people and the descriptions are assumed to be correct. Some studies involve artifical OBEs, which can be argued to be different from the natural OBEs.
OBE (artificially induced OBEs) (AO1)
Ehrsson (2007) argued that OBEs are due to the disconnection from brain circuit that deals with visual and tactile information. He had 42 participants who stood in from of a camera (one at a time), while wearing video-display goggles. The image on the goggle produced a 3D image of the participants back in front of them. A pen was stroked along their back, the participants saw this happen on the image in the goggles.
Participants often reported the pen being stroked down the back of the image infront of them (produced by the goggles). The equipment was turned off and when the participant was repositioned and asked to return to the position they were in when they had their back stroked by a pen. The participants usually stood in the position when the projecting would have been standing in the projections from the goggles.
OBE (artificially induced OBEs) (AO2)
Ehrsson claimed that his experiment showed that OBEs were due to the imagination and their senses were relocated into the projected body.
However, the small sample of volunteers means the experiement can't be generalised to the general population. Also, to keep the participants from guessing the aims of the study, there are ethical issues, such as full informed consent is not likely. Confidentiality is ensured however.
Blakemore (2008) commented on the study, argueing that dispite many argueing that artificial OBEs are differnet from natural ones, that this study has shown that OBEs can be created in a lab and therefore tested one theory on why/how OBEs occur.
Psychological study of OBEs
Blanke et al (2002) accidently created OBEs when they electrical stimulated the Temporal-parietal Junction (TPJ) in a woman with epilepsy. This was then tried on women without epilepsy, they also found that OBEs occured. When other parts of the brain were stimulated, there was no OBE occurance.
However, the small and biased sample (only women) makes it hard to generalise the results to the general population.
Commentray of OBEs (AO2)
Paranormal explination - The reason for their occurrence is currently beyond our knowledge.
Anomalistic explination - OBEs are connected to either sensory disturbance or stimulation to the temporla-parietal junction (TPJ).
Gow et al (2004) believes that belief in OBE are linked to personality factors. In a study, 167 participants (either a believer of non-believer) were asked to fill in a questionnaire. Those who had experienced a OBE was found to be fantasy prone (FP) and had a greater belief. However, it is hard to determine cause and effect, does the OBE cause the FP or the FP cause the OBE.
Natural NDEs (AO1)
Moody (1975) Looked at hundreds of cases of NDE and found they mainly occured when a person was near death (obviously) or was clinically died, but 'revived'. A NDE can occur following fainting, or during stress or life and death situations. His book caused many a huge wave of research. Ring (1980) looked at 100 people who experienced NDEs and found a 'core experience' of common themes. Around 20% of heart attack survivers had NDEs (Fox, 2006)
- Floating above your body
- Rapidly moving through darkness towards a light
- A sence of spiritual light
- Seeing Jesus, God or deceased relative/friends
- Sometimes a 'choice' to return to life or being told "its not your time"
Challenges to beliefs in NDEs (AO2)
NDEs occur near death, raising the question of if there is a psychological cause. Parapsycologist argue NDEs are proof of life after death. Van Lommel et al (2001) followed 344 cardiac arrest survivors and found that those who experienced NDEs found it to be life changing and spiritual. Those who didn't experience a NDE still feared death.
However, Blackmore argues that biological and medical phenomena can be used to challege the 'exceptional and meaning experince'. It is suggested that endorphin is released during pain or stress and can lead to a sense of euphoria, causing a detachment from reality.
Ketamin (origianlly a horse tranqualiser) is now used by some people to gain the euphoria experience, producing the common NDE sensations/properties.
Research also suggests that NDES are due to REM intrusions, creating hallucinations. The REM sleep is triggered by hypoxia (i.e. fainting), shutting down parts of the brain, but activates the brain stems.
Paranormal explinations are also argued to be reductionist, the brain is complex.