WEDNESDAY, Oct. 31 (HealthDay News) -- New research is taking a little of the mystery out of the phenomenon known as the "out-of-body" experience.

A team of Belgian scientists have linked the sense of disembodiment central to the experience -- the feeling of leaving one's body and then floating outside it -- to abnormal activity in a specific region of the brain.

This activity appears to short-circuit the processing of sensory information and the ability to locate oneself in time and space, the team said.

"Self-perception is nothing else but a creation of your brain," explained study lead author and neurosurgeon Dr. Dirk De Ridder, of the neurosurgical department at Antwerp University. "We found a key spot in the brain in which different areas are normally activated whenever stimulus comes in, so you can relate that stimulus to yourself, which helps create a unified perception of ourselves."

"The 'total perception of self,' " he added, "is built out of different parts. And one of these parts is that your consciousness belongs within your body."

"But when something goes wrong in that brain area so that the integration of all the incoming information -- sight, sound, smell, the senses -- is not happening as it should, then you can feel that you're not in your body," De Ridder said. "You can get an out-of-body experience. You're perfectly conscious. But you just feel as if you're not actually sitting in your body."

His team reported its finding in the Nov. 1 issue of the New England Journal of Medicine.

De Ridder's team discovered what they believe is a hardwired connection between the out-of-body experience and specific abnormal brain activity. They did so while observing the unanticipated side-effects of a treatment offered to a 63-year-old Belgian patient suffering from tinnitus, more commonly known as "ringing in the ears."

To alleviate his condition, doctors had implanted electrodes in a region in the right side of the man's brain known as the temporoparietal junction.

Unfortunately, stimulation of the electrodes failed to halt the ear-ringing. However, in the process of doing so, the attending physicians found that the patient repeatedly experienced what he described as an out-of-body experience.

By monitoring the use of a patient-controlled button pressed at the start and end of each experience, researchers found that within one second following electrode stimulation to the brain, out-of-body experiences were provoked -- each lasting from 15 to 21 seconds an episode.

While at no time causing any alteration in his sense of consciousness, during each episode, the patient consistently reported feeling disembodied to a specific location -- namely about 20 inches behind his body and to the left. The perception remained the same, regardless of whether the patient was standing or lying down during electrode stimulation.

At no time did the patient report the sense that he was watching his actual body from another place -- a phenomenon known as autoscopy. Rather, he said that throughout each out-of-body episode, he visually perceived the world as usual -- from the vantage point of his actual body. At the same time, however, he continued to feel as if his body was located elsewhere.

During repeated actual and false (placebo) stimulations, the researchers conducted 12 PET scans of the patient's brain.

The scans revealed that throughout each out-of-body episode, brain activity spiked in two areas surrounding the electrode implant: a small area where the angular gyrus meets the supramarginal gyrus, and in the rear section of the superior temporal cortex.

The former area is known for being associated with integrating sensory stimulus -- such as sight, sound, and touch -- in order to establish head and body orientation in space.

The latter area is known to be integral to the forming of a so-called "map" of self-perception -- a key ingredient in establishing self-consciousness.

The researchers concluded that electrode stimulation of these two areas seems to alter a person's spatial self-perception, while leaving global self-consciousness -- the ability to perceive the surrounding world -- untouched. The result: an out-of-body experience.

However, they cautioned that while epileptics, patients suffering from migraines and tinnitus, and those undergoing a near-death experience have all been known to spontaneously experience out-of-body episodes, it remains unclear whether pro-actively stimulating the two identified cranial areas -- which don't normally activate in unison -- would induce a similar experience in healthy individuals.

"It's fairly rare," said De Ridder. "It might be possible to trigger this experience -- and even likely -- in a normal brain, and mess up the normal integration of the functions, the senses. But we're not sure yet."

"It's fascinating," commented Paul Sanberg, a distinguished university professor and director of the Center of Excellence for Aging and Brain Repair with the University of South Florida's College of Medicine in Tampa.

"This gives a physiological mechanism for out-of-body experiences under different conditions," he said. "And, it points out that our sense of self isn't just our cognitive abilities and our emotions, but it's also our sense of time and space."

"So, I imagine if you can stimulate a part of the brain that has been found to control where we are in space and orientation and our sense of body, it could give a sense of being out of our body," he said. "It could give us a sense that we are somewhere else. Perhaps not a real out-of-body experience. But a perceptual experience, nonetheless."

More information

For more on the brain and sensory perception, visit the Howard Hughes Medical Institute  .

SATURDAY, Oct. 27 (HealthDay News) -- In 2006, an estimated 1.1 million people were treated at U.S. hospital emergency departments for head injuries related to common household products and settings such as ladders, steps, and showers, the federal Consumer Product Safety Commission reports.

The actual number of head injuries suffered by people in their homes is likely greater, since many injuries are treated at doctor's offices and immediate-care centers, or people don't seek any medical treatment, says the American Association of Neurological Surgeons (AANS).

Many head injuries are caused by falls, which are the leading cause of death and serious injury among Americans 65 and older. Among older adults, falls are the most common cause of traumatic brain injury, which account for 46 percent of fatal falls among older adults.

In addition, traumatic brain injury is the leading cause of death and severe injury in children who suffer falls.

Simple precautions can help prevent falls and serious or deadly head injuries, says the AANS, which offers the following safety tips:

• Secure loose electrical cords and put away toys and other items that are lying around on floors, stairs, etc.
• Use safety gates and install window guards to protect young children.
• Secure rugs and lift them periodically to inspect the backing for wear.
• Don't walk on slippery, freshly washed floors and avoid floor waxes.
• Install grab bars and handrails if you are frail or elderly.
• Improve the lighting in your home; dim lighting can increase the risk of falls.
• Install night lights in halls and bathrooms and keep a flashlight near your bed.
• Store items in easy-to-reach places; use stepstools or ladders only when absolutely necessary.
• Check all stair railings and steps.
• Don't wear any clothing that interferes with your vision.
• Wear proper shoes with slip-resistant soles.
• Inspect and remove debris from walkways, driveways, porches and yards.
• In winter, remove ice and snow from areas where people walk.
• Inspect and remove debris from lawns before mowing or gardening.
• Store outdoor equipment properly.
• Make sure ladders are stable and secure before you use them.

More information

The American Academy of Orthopaedic Surgeons has more about fall prevention  .

THURSDAY, Oct. 25 (HealthDay News) -- U.S. researchers say they've determined the molecular structure of a cellular receptor that's key to how the body reacts to drug treatment.

The beta 2-adrenergic receptor is one of many G protein-coupled receptors on cells that play an important role in drug response, say scientists at the Scripps Research Institute and the Stanford University School of Medicine, Calif.

Reporting Oct. 25 in two Science Express articles, the team said that identifying the structure of G protein-coupled receptors may help bring new drugs that precisely bind to specific receptors on the surfaces of cells. That would make the drugs more effective and less likely to cause side effects, they said.

Currently, more than half of all drugs work by targeting a particular receptor on cells.

"The majority of hormones and neurotransmitters work through one of these (G protein-coupled) receptors," senior author Dr. Brian Kobilka, professor of molecular and cellular physiology, said in a prepared statement. "All these receptors are structurally related, which means that knowing more about a specific one will advance the whole field."

"These receptors are ideal candidates for therapeutics for many types of diseases," he added.

More information

The U.S. National Institute of General Medical Sciences has more about how drugs work in the body.

WEDNESDAY, Oct. 24 (HealthDay News) -- Changing to daylight savings time may give people an hour more of sunlight, but it appears that their internal body clocks never really adjusts to the change, German researchers report.

In fact, daylight savings time can cause a significant seasonal disruption that might have other effects on our bodies, according to the report in the Oct. 24 online edition of Current Biology.

"When you change clocks to daylight savings time, you don't change anything related to sun time," explained lead researcher Till Roenneberg of Ludwig-Maximilians-University in Munich. "This is one of those human arrogances -- that we can do whatever we want as long as we are disciplined. We forget that there is a biological clock that is as old as living organisms, a clock that cannot be fooled. The pure social change of time cannot fool the clock."

People's circadian rhythm -- the body's internal clock -- follows the sun and changes depending on where you live. It actually changes in four-minute intervals, exactly the time it takes for the sun to cross one line of longitude, Roenneberg explained.

"The circadian clock does not change to the social change," Roenneberg said. "During the winter, there is a beautiful tracking of dawn in human sleep behavior, which is completely and immediately interrupted when daylight savings time is introduced in March," he said. It returns to normal this year when standard time returns on Nov. 4, he added.

Daylight savings time may be one cause of what Roenneberg called our lack of seasonality. By seasonality, he means that our internal clock is in tune with the natural change in light throughout the year. "This could have long-term effects," he said.

In the study, Roenneberg's group collected data on the sleep patterns of 55,000 people in Central Europe. The researchers found that sleep time on days off work when daylight savings time took effect followed the seasonal progression of dawn under standard time, but not under daylight savings time.

In a another study, Roenneberg's group looked at the timing of sleep and activity for eight weeks during the change to daylight savings time in 50 people, taking into account each person's natural clock preferences, or "chronotypes," which range from morning larks to night owls.

For both morning larks and night owls, their timing for sleep and peak activity easily adjusted when daylight savings time ended in the fall. However, it never adjusted to the return to daylight savings time in spring. This was especially true for night owls -- those who stay up late and sleep late.

"If we didn't change to daylight savings time, people would adjust to dawn during the summer and again to dawn in the autumn," Roenneberg. "But this natural adjustment is interrupted by daylight savings time," he said.

One expert believes daylight savings time is only one of the ways we try to fool our biological clock.

"It is not surprising that when you change our time to respond to something other than the sun and daylight that different chronotypes are going to have a difficult time," said Dr. Louis Ptacek, an investigator at the Howard Hughes Medical Institute and the John C. Coleman Distinguished Professorship in Neurodegenerative Diseases at the University of California, San Francisco.

"Before artificial lighting, humans tended to live much more by the sun cycle," Ptacek said. "Whereas, now, people stay up all night and turn the lights on, which affects our biological clock. There is no question that we have been changing our clocks long before daylight savings time came along."

So, it's not surprising that daylight savings time affects our internal clock, Ptacek said. However, it is no more unnatural than our use of artificial light, he noted.

There is no reason to abandon daylight savings time, Ptacek added. "There may be societal benefits to daylight savings time, such as saving energy," he said. In any case, it is no more disruptive than the other things we do to manipulate time, he said.

Another expert believes daylight savings time isn't really useful, however.

"I don't think it is valuable to change to daylight savings time," said Ralph Downey III, the chief of sleep medicine at Loma Linda University Medical Center in California. "Five o'clock to the body clock is five o'clock," he said. "But, socially, things change, and that's also a time-giver."

More information

For more on the body's clock, visit the U.S. National Institute of Mental Health.