By Emma Young
People who’ve had an out-of-body experience (OBE) report that their conscious awareness shifted outside their physical body – often upwards, so they felt like they were floating above their own head. It’s thought that OBEs occur when the brain fails to properly integrate data from the different senses, including vision, touch, proprioception (the sense of where the limbs and other body parts are located in space) and from the vestibular system (organs in the inner ear that monitor head orientation, balance and motion).
Previous research has mostly focused on the role of vision and touch – for example by triggering the illusion of viewing one’s own body – but the vestibular system has largely been neglected. If it does play an important role we should expect that problems with the vestibular system – which often present as feelings of dizziness – lead to OBEs, but do they?
Historical case studies suggested that they might. And now, published in Cortex, the first systematic study of patients referred to a neurological specialist because of dizziness has found that they can.
Christophe Lopez, a neuroscientist at Aix Marseille University, and Maya Elziere, a neurologist specialising in balance disorders at the Hôpital Européen, also in Marseille, France, compared 210 patients referred to them for dizziness and vertigo (having the feeling of spinning, swaying or tilting, being off balance, or that the room is spinning) with the same number of age and gender-matched controls. They found that the patients were much more likely to report having had an OBE – 14 per cent had had at least one, compared with 5 per cent of the healthy controls. And most of these patients reported having an OBE only after their dizziness had started.
During their OBE, most of the patients reported vestibular sensations – of elevation and lightness, for example. (One reported a “sensation of entering my body, like in an envelope, from the top”). The vast majority of these patients also reported having had not just one but multiple OBEs, which usually lasted for a few seconds or a few minutes.
OBEs were linked mainly to dizziness caused by obvious problems with the vestibular system itself such as vestibular neuritis and Meniere’s disease (rather than being brain-based). Yet, most patients with these same vestibular problems did not develop OBEs so something else must be going on to contribute to the experience. Questionnaire results showed that scores for “depersonalisation-derealization”, depression and anxiety, were the main predictors of OBE in patients with dizziness, suggesting these psychological factors interact with the physical problem of atypical signals being sent from the vestibular system to generate OBEs. In healthy controls, there was also a relationship between depersonalisation-derealization scores and reported OBEs. This isn’t a surprise: depersonalisation-derealization involves feelings of observing yourself from outside your body, or having the sense that things around you aren’t real.
As anxiety was also a significant predictor – and anxiety is known to be linked to vertigo – “we suggest that anxiety and depersonalisation-derealization may combine to precipitate OBE in patients with dizziness,” the researchers write.
Article source: http://feedproxy.google.com/~r/BpsResearchDigest/~3/COtoBpxF5N0/