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They have been interpreted as evidence of the existence of a soul and even life after death, but now scientists may have unravelled what is going on when people have out-of-body experiences.

Researchers devised a devious experiment to trick volunteers into thinking they had left their own body while undergoing brain scans.

They found that specific areas of the brain lit up with activity according to where in the room a person thought they were.

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MRI scans revealed that specific areas of the brain lit up (pictured) according to where in the room participants believed they were during an 'out-of-body experience'. It found that neurons known as place cells were involved and research in rats has shown these cells work like the brain's GPS

It suggests that abnormal activity in these areas, perhaps under the influence of drugs or when deprived of oxygen, could be responsible for creating out-of-body experiences.

The researchers used video headsets that gave participants a view of the room they were in from another persons perspective - in effect 'teleporting' them out of their body to another location.

HOW IT FEELS TO BE INVISIBLE

Researchers have discovered it is possible to trick a person into thinking they are invisible simply by using a virtual reality headset.

The study by neuroscientists at Sweden's Karolinska Institute also found an illusion of invisibility can help people deal with socially stressful situations more easily.

They asked 125 people to wear a virtual reality headset while standing upright and to look down towards their body.

Participants wore a VR headset but instead of seeing their body, they were shown an empty space (left) or a mannequin (right)

Instead of seeing their body, they were shown either the body of a mannequin or an empty space where their body should have been.

A researcher then stroked the participant's body with a paintbrush while simultaneously moving another paintbrush in the corresponding location in the empty space, as if they were touching an 'invisible body'.

The researchers also examined whether the feeling of invisibility can play a role in social anxiety by placing the participants in front of an audience of strangers.

Their heart rate and stress levels was lower if they had experienced the invisible body illusion before hand.

The illusion made the volunteers in the scanner believe they were actually in a stranger's body on the other side of the room, looking back at their own body in the MRI machine.

In some of the experiments, the scientists even touched or threatened the stranger's body with knives to examine how the volunteer's brain would react.

Arvid Guterstam, a neuroscientist at the Karolinska Institute and lead author of the study, said: 'The sense of being a body located somewhere in space is essential for our interactions with the outside world and constitutes a fundamental aspect of human self-consciousness.

'Our results are important because they represent the first characterization of the brain areas that are involved in shaping the perceptual experience of the bodily self in space.'

The researchers asked 15 healthy volunteers to wear head-mounted displays that showed them lying in the MRI scanner from another part of the room, from the perspective of a stranger lying down.

The volunteers could see a pair of legs and feet as if they were lying on their back, but could also see their own legs and feet sticking out of the scanner.

By touching the volunteers body with an object at the same time as identical touches were performed on the stranger's body they were viewing from in the headset, the researchers were able to cement the illusion.

Mr Guterstam said: 'In a matter of seconds, the brain merges the sensation of touch and visual input from the new perspective, resulting in the illusion of owning the stranger's body and being located in that body's position in the room, outside the participant's physical body.'

Brain scans taken while this was happening revealed that the activity patterns in the temporal and parietal lobes matched this misplaced sense of self-location.

They also found that there was particular activity in the hippocampus - an area of the brain where a type of neuron known as 'place cells' have been identified.

Research in rats has shown that these 'place cells' work like the brain's GPS, helping to locate its position in the room.

It could mean that unusual activity in these cells may be partly responsible for causing out-of-body experiences. 

The participants in the MRI scanner wore headsets that gave them a view like the one above, creating the illusion they were in a strangers body on the other side of the room looking at themselves in the scanner

Does it work? Out-of-body illusion in a brain scan experiment

The scientists changed the perspective of the video headset as shown in the graphics and images above and found the activity in the participant's brain changed according to where in the room they thought they were

Most people who claim to have had an out-of-body experience have been close to sleep in a lucid-dream state, or following severe physical trauma where they have a near death experience.

Others claim to have had such experiences after taking hallucinogenic drugs or mushrooms.

Professor Henrik Ehrsson, a neuroscientist who oversaw the study, said: 'This finding is particularly interesting because it indicates that place cells are not only involved in navigation and memory encoding, but are also important for generating the conscious experience of one's body in space.'