Thursday, September 11, 2008

Near Death Experiences May Have Biological Explanation, Say Scientists

For centuries people have been talking about near-death experiences, where the patient has an out-of-body experience and remembers seeing a bright light and feels a great sense of peace. We have linked this experience with knocking on the doors of heaven, to many other spiritual explanations. According to a new study, there might be a biological explanation for this.

According to a team of researchers from University of Kentucky, while a person is undergoing a near death experience the same parts of his/her brain are activated as the brain of a person who is having a dream. The scientists compared 110 people, half had never had a near death experience, while the other half had.

They found that the people who had had a near death experience had less clearly separated boundaries between periods of sleep and wakefulness. The near death experience people reported looking down at themselves in the operating theatre or being bathed in a bright, white light. When a person is in a REM (Rapid Eye Movement) sleep stage, similar sensations also happen.

... The researchers say they cannot rule out a spiritual explanation for a near death experience. They say that, as scientists, their job is to find out what is going on physically. It is not their job to find out why.  Just like dreams can seem really real, so can near death experiences, say the researchers. - medicalNews

Also note, experiments show that out of body experiences are due to brain functioning.
The Sept. 21 issue of Nature magazine includes an account by Dr. Blanke and his colleagues of the woman who sensed a shadow person behind her. They described the out-of-body experiences in the February 2004 issue of the journal Brain.

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. ...

Because the presence closely mimicked the patient’s body posture and position, Dr. Blanke 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.

The feeling of a shadowy presence can occur without electrical stimulation to the brain, Dr. Brugger said. It has been described by people who undergo sensory deprivation, as in mountaineers trekking at high altitude or sailors crossing the ocean alone, and by people who have suffered minor strokes or other disruptions in blood flow to the brain.

Six years ago, another of Dr. Blanke’s patients underwent brain stimulation to a different multisensory area, the angular gyrus, which blends vision with the body sense. The patient experienced a complete out-of-body experience.

When the current flowed, she said: “I am at the ceiling. I am looking down at my legs.”

When the current ceased, she said: “I’m back on the table now. What happened?”

Further applications of the current returned the woman to the ceiling, causing her to feel as if she were outside of her body, floating, her legs dangling below her. When she closed her eyes, she had the sensation of doing sit-ups, with her upper body approaching her legs.

Because the woman’s felt position in space and her actual position in space did not match, her mind cast about for the best way to turn her confusion into a coherent experience, Dr. Blanke said. She concluded that she must be floating up and away while looking downward.

Some schizophrenics, Dr. Blanke said, experience paranoid delusions and the sense that someone is following them. They also sometimes confuse their own actions with the actions of other people. While the cause of these symptoms is not known, he said, multisensory processing areas may be involved. - nytimes

Many things like this that I have read lead to my being not particularly religous.

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