By JOSEPH B. VERRENGIA, AP Science Writer
"Their stories are the stuff of creepy movies and daytime
TV: Hospital patients resuscitated on the operating table speak
of being drawn toward a brilliant light, or looking down on their
own bodies and the doctors working feverishly to save their lives. "
What induces these brief, haunting images?
A new study suggests these "out-of-body" and "near-death" experiences may be influenced by a portion of the brain misfiring under stress.
The paper, which describes one patient's visions while she was being evaluated for epilepsy, does not wrestle with issues of the soul.
Nor, researchers said, do the brain-mapping results entirely explain these strange reports.
The researchers point to a processing center in the brain known as the angular gyrus. The angular gyrus is thought to play an important role in the way the brain analyzes sensory information to give us a perception of our own bodies. When it misfires, they speculate, the result can be visions of floating outside of ourselves.
The findings were published in Thursday's issue of the journal Nature.
"We do not fully understand the neurological mechanism that causes OBEs," conceded the study's lead researcher, neurologist Dr. Olaf Blanke at the University Hospitals of Geneva and Lausanne in Switzerland.
Skeptics of OBEs said the experiment goes a long way toward providing a scientific explanation for what some believe is a paranormal phenomenon, even if the study is based on only one patient.
"Since all of our brains are wired in a similar manner, there is no reason to think that stimulation of this brain region in other patients will not corroborate the finding," said psychologist Michael Shermer, director of the Skeptic Society, which seeks to debunk alien abductions, ESP and other claims.
"It's another blow against those who believe that the mind and spirit are somehow separate from the brain," Shermer said. "In reality, all experience is derived from the brain."
Other researchers were less dismissive of the possibility that OBEs might be real. They described the experiment as modest but interesting.
Neurologist Dr. Bruce Greyson of the University of Virginia said the experiment does not necessarily prove that all OBEs are illusions. He said it is possible that some OBEs occur in different ways than the scientists suspect.
The Swiss researchers mapped the brain activity of a 43-year old woman who had been experiencing seizures for 11 years. They implanted electrodes to stimulate portions of her brain's right temporal lobe.
The temporal lobe, which includes the angular gyrus structure, is associated with perception of sound, touch, memory and speech.
Blanke suspects that the right angular gyrus integrates signals from the visual system, as well as information on touch and balance.
When electrical stimulation was applied, the patient reported seeing herself "lying in bed, from above, but I only see my legs and lower trunk." She also described herself as "floating" near the ceiling.
Millions of people have reported OBEs, but relatively few have been clinically analyzed.
Last December, the British medical journal Lancet published a Dutch study in which 344 cardiac patients were resuscitated from clinical death. About 12 percent reported seeing light at the end of a tunnel, or speaking to dead relatives.
Other researchers have suggested that OBEs occur as brain cells
die from lack of oxygen, or when the brain releases pain-reducing
chemicals called endorphins.[/quote] What'dya think?