Monday, November 20, 2006

Out of Body experiences triggered by electrical simulation of the angular gyrus

Yet another notch for science. We have all read about mystical sounding abnormal 'out of body' experiences where people seem to inhabit a non-corporeal self and seem to look down upon their own bodies from a position outside their body. Rational explanation for a lot of this could not be unearthed and it was thought that either these people were faking it or these people were closer to some superior force. Some people were just waiting for a rational scientific explanation. Looks like the people who were waiting just got it...

Dr. Olaf Blanke, a neurologist at the École Polytechnique Fédérale de Lausanne in Switzerland reported in the Sept. 21 issue of Nature magazine of cases of women who sensed a shadow person behind her on electrical simulation to certain parts of the brain.

As we know the angular gyrus in the temporal parietal junction forms one of the higher association areas for senses like vision, sound and touch. Located behind the somatosensory strip and ventral to the primary visual areas with inputs from the speech and sound areas, it is possible that this area could provide a representation for our 'self' in a rudimentary form (in the same sense as one gets a feeling for a 'phantom limb'). On electrical simulation to this area, people have reported seeing or feeling detached from the corporeal self and have also found to experience intriguing behavior.

"There is nothing mystical about these ghostly experiences, said Peter Brugger, a neuroscientist at University Hospital in Zurich, who was not involved in the experiments but is an expert on phantom limbs, the sensation of still feeling a limb that has been amputated, and other mind-bending phenomena.

“The research shows that the self can be detached from the body and can live a phantom existence on its own, as in an out-of-body experience, or it can be felt outside of personal space, as in a sense of a presence,” Dr. Brugger said. "

The woman replied that she had a weird sensation that another person was lying beneath her on the bed. The figure, she said, felt like a “shadow” that did not speak or move; it was young, more like a man than a woman, and it wanted to interfere with her.
When the current was turned off, the woman stopped looking to the right, and said the strange presence had gone away. Each time he reapplied the current, she once again turned her head to try to see the shadow figure.

When the woman sat up, leaned forward and hugged her knees, she said that she felt as if the shadow man was also sitting and that he was clasping her in his arms. She said it felt unpleasant. When she held a card in her right hand, she reported that the shadow figure tried to take it from her. “He doesn’t want me to read,” she said.

Because the presence closely mimicked the patient’s body posture and position, the doctor performing the test concluded that the patient was experiencing an unusual perception of her own body, as a double. But for reasons that scientists have not been able to explain, he said, she did not recognize that it was her own body she was sensing

Read on more here.

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