near death' experiences
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PNAS|Near death experience|EEG|University of Michigan Medical School|University of Michigan
Researchers
at the University of Michigan have found that there is a surge of
electrical activity in the brain at the time of cardiac arrest (heart
attack).
RELATED
NEW
DELHI: What does one feel at the moment of death? There are hundreds of
recorded cases of patients who nearly died but were saved by medical
intervention. They had gone through a "near-death experience". Most of
them report a sense of peace and painlessness, and a vision of bright
light. Other report feelings or visions associated with their cultural
beliefs.
So what is exactly happening? There is considerable controversy on this. Now, researchers at the University of Michigan have found that there is a surge of electrical activity in the brain at the time of cardiac arrest (heart attack). This unusual activity was recorded for the first time by the scientists in rats which were undergoing simulated cardiac arrest.
Led by author Jimo Borjigin, associate professor at the University of Michigan Medical School the study shows that shortly after clinical death, in which the heart stops beating and blood stops flowing to the brain, rats display brain activity patterns characteristic of conscious perception. The study is published in this week's Proceedings of National Academy of Science ( PNAS) Early Edition.
"This study, performed in animals, is the first dealing with what happens to the neurophysiological state of the dying brain," Borjigin said, according to a statement of the University..
"It will form the foundation for future human studies investigating mental experiences occurring in the dying brain, including seeing light during cardiac arrest," she said.
Approximately 20 percent of cardiac arrest survivors report having had a near-death experience. These visions and perceptions have been called "realer than real," according to previous research, but it remains unclear whether the brain is capable of such activity after cardiac arrest.
"We reasoned that if near-death experience stems from brain activity, neural correlates of consciousness should be identifiable in humans or animals even after the cessation of cerebral blood flow," Borjigin said.
Researchers analyzed the recordings of brain activity called electroencephalograms (EEGs) from nine anesthetized rats undergoing experimentally induced cardiac arrest.
Within the first 30 seconds after cardiac arrest, all of the rats displayed a widespread, transient surge of highly synchronized brain activity that had features associated with a highly aroused brain.
Furthermore, the authors observed nearly identical patterns in the dying brains of rats undergoing asphyxiation.
"The prediction that we would find some signs of conscious activity in the brain during cardiac arrest was confirmed with the data," says Borjigin.
"But, we were surprised by the high levels of activity," adds study senior author anesthesiologist George Mashour, assistant professor of anesthesiology and neurosurgery at the U-M, the University statement said.
"In fact, at near-death, many known electrical signatures of consciousness exceeded levels found in the waking state, suggesting that the brain is capable of well-organized electrical activity during the early stage of clinical death," he added
The brain is assumed to be inactive during cardiac arrest. However the neurophysiological state of the brain immediately following cardiac arrest had not been systemically investigated until now.
"This study tells us that reduction of oxygen or both oxygen and glucose during cardiac arrest can stimulate brain activity that is characteristic of conscious processing," says Borjigin. "It also provides the first scientific framework for the near-death experiences reported by many cardiac arrest survivors."
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Isaac Newton quotes
“To myself I am only a child playing on the beach, while vast oceans of truth lie undiscovered before me.”
TODAY’S SCIENTISTS BELIEVE HE KNOWS EVERYTHING AND HIS RESEARCH IS THE FINAL ANSWER
-------------------------------------------------------------------------------------------------------------------------------
pulling the rug out from under Einstein's principle
following the known laws of physics would lead to a contradiction, the firewall paradox.
http://timesofindia.indiatimes.com/home/science/Black-Hole-mystery-This-time-they-say-Einstein-might-really-be-wrong/articleshow/21808286.cms
VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
So what is exactly happening? There is considerable controversy on this. Now, researchers at the University of Michigan have found that there is a surge of electrical activity in the brain at the time of cardiac arrest (heart attack). This unusual activity was recorded for the first time by the scientists in rats which were undergoing simulated cardiac arrest.
Led by author Jimo Borjigin, associate professor at the University of Michigan Medical School the study shows that shortly after clinical death, in which the heart stops beating and blood stops flowing to the brain, rats display brain activity patterns characteristic of conscious perception. The study is published in this week's Proceedings of National Academy of Science ( PNAS) Early Edition.
"This study, performed in animals, is the first dealing with what happens to the neurophysiological state of the dying brain," Borjigin said, according to a statement of the University..
"It will form the foundation for future human studies investigating mental experiences occurring in the dying brain, including seeing light during cardiac arrest," she said.
Approximately 20 percent of cardiac arrest survivors report having had a near-death experience. These visions and perceptions have been called "realer than real," according to previous research, but it remains unclear whether the brain is capable of such activity after cardiac arrest.
"We reasoned that if near-death experience stems from brain activity, neural correlates of consciousness should be identifiable in humans or animals even after the cessation of cerebral blood flow," Borjigin said.
Researchers analyzed the recordings of brain activity called electroencephalograms (EEGs) from nine anesthetized rats undergoing experimentally induced cardiac arrest.
Within the first 30 seconds after cardiac arrest, all of the rats displayed a widespread, transient surge of highly synchronized brain activity that had features associated with a highly aroused brain.
Furthermore, the authors observed nearly identical patterns in the dying brains of rats undergoing asphyxiation.
"The prediction that we would find some signs of conscious activity in the brain during cardiac arrest was confirmed with the data," says Borjigin.
"But, we were surprised by the high levels of activity," adds study senior author anesthesiologist George Mashour, assistant professor of anesthesiology and neurosurgery at the U-M, the University statement said.
"In fact, at near-death, many known electrical signatures of consciousness exceeded levels found in the waking state, suggesting that the brain is capable of well-organized electrical activity during the early stage of clinical death," he added
The brain is assumed to be inactive during cardiac arrest. However the neurophysiological state of the brain immediately following cardiac arrest had not been systemically investigated until now.
"This study tells us that reduction of oxygen or both oxygen and glucose during cardiac arrest can stimulate brain activity that is characteristic of conscious processing," says Borjigin. "It also provides the first scientific framework for the near-death experiences reported by many cardiac arrest survivors."
-----------------------------------------------------------------------------------------------------------------------------
Isaac Newton quotes
“To myself I am only a child playing on the beach, while vast oceans of truth lie undiscovered before me.”
TODAY’S SCIENTISTS BELIEVE HE KNOWS EVERYTHING AND HIS RESEARCH IS THE FINAL ANSWER
-------------------------------------------------------------------------------------------------------------------------------
pulling the rug out from under Einstein's principle
following the known laws of physics would lead to a contradiction, the firewall paradox.
http://timesofindia.indiatimes.com/home/science/Black-Hole-mystery-This-time-they-say-Einstein-might-really-be-wrong/articleshow/21808286.cms
VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
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