By Tanya Lewis via LiveScience
SAN DIEGO — The human mind effortlessly constructs the feeling of inhabiting a body, and now scientists are figuring out how the brain produces that experience.
Recent studies have shown that the brain incorporates information from multiple senses and the first-person visual perspective to create a sense of body ownership. But it’s still unclear how the brain perceives the body’s location in space.
In the study, which has not yet been published in a scientific journal, participants lay inside an MRI scanner while wearing a head-mounted display that showed a first-person camera view of another person’s body lying in a corner of the scanner room, with their head either parallel to a wall or perpendicular to it. Researchers from the Karolinska Institutet in Sweden repeatedly touched each participant with an object while simultaneously touching the body shown in the camera view. This gave participants the illusion that the body in the camera view belonged to them.
To heighten the illusion, the researchers used . . .
What happens in the brain when a person has an out-of-body experience? A team of scientists may now have an answer.
In a new study, researchers using a brain scanner and some fancy camera work gave study participants the illusion that their bodies were located in a part of a room other than where they really were. Then, the researchers examined the participants’ brain activity, to find out which brain regions were involved in the participants’ perceptions about where their body was.
The findings showed that the conscious experience of where one’s body is located arises from activity in brain areas involved in feelings of body ownership, as well as regions that contain cells known to be involved in spatial orientation, the researchers said. Earlier work done in animals had showed these cells, dubbed “GPS cells,” have a key role in navigation and memory.
The feeling of owning a body “is a very basic experience that most of us take for granted in everyday life,” said Dr. Arvid Guterstam, a neuroscientist at the Karolinska Institutet in Sweden, and co-author of the study published today (April 30) in the journal Current Biology. But Guterstam and his colleagues wanted to understand the brain mechanisms that underlie this everyday experience.
Rubber hands and virtual bodies
In previous experiments, the researchers had explored the feeling of being out of one’s body. For example, the researchers developed the so-called “rubber hand illusion,” in which a person wearing video goggles sees a rubber hand being stroked, while a researcher strokes the participant’s own hand (which is out of sight), producing the feeling that the rubber hand is the participant’s own. The researchers have used a similar technique to give people the feeling of having a manikin’s body, or even an invisible body, as they described in a report published last week in the journal Scientific Reports.
In the new study, Guterstam and his colleagues . . .
By J. Francis Wolfe via Listverse
There is very good reason for all of humanity to have a healthy curiosity relating to near-death experiences. Death is the one experience we are all guaranteed to ultimately share. The field of science has therefore made numerous attempts to explain the near-death phenomena that so many people have independently described.
10 • The Temporoparietal Junction May Be Responsible For Out-Of-Body Experiences
Among the more common elements of near-death experiences is the distinct feeling of an individual having left their worldly body. Those who have had an “out-of-body” experience often report floating above themselves while being able to see their body and the people surrounding them. There have even been a few reports in which those who have had an out-of-body experience can identify objects and events occurring during times in which they were considered clinically dead, but there have also been studies demonstrating that this all could be due to damage in the temporoparietal junction of the brain.
The temporoparietal junction is responsible for assembling the data collected by the body’s senses and organs to form the perception of an individual’s body. When this part of the brain is damaged, it is possible that this results in the “out-of-body” experience that so many people have reported.
Though the experience may appear to be incredibly vivid and real, scientific studies have been able to reproduce this phenomenon without bringing the subject close to death, simply by electrically stimulating the temporoparietal junction of the brain.
9 • Excess Carbon Dioxide May Create The Tunnel And White Light
Nearly every individual who has had a near-death experience discusses the existence of a bright, white light and a tunnel that seems to lead to the afterlife. The white light seems to take on an otherworldly quality and is often accompanied by an overwhelming sense of peacefulness and welcoming.
A 2010 study of patients who had heart attacks revealed that there may be a correlation between this type of near-death experience and the level of CO2 in the blood. Out of the 52 cardiac patients studied, 11 reported a near-death experience. The levels of CO2 in the blood of those 11 patients were significantly higher than the patients who did not report having a near-death experience.
The feeling among researchers is that the excess CO2 in the bloodstream can have a significant effect on vision, which leads to patients seeing the tunnel and the bright light.
8 • Lack Of Oxygen To The Brain Causes Hallucinations
Many near-death experiences include the presence of long-dead friends and relatives appearing and perhaps even guiding the individual as they pass from the world of the living to the afterlife. Memories from every part of life are recalled in rapid succession, and there is an overwhelming sense of comfort, yet it appears that scientific research has provided an explanation for this phenomenon as well.
While excess CO2 has an effect on vision during a near-death experience, a lack of oxygen to the brain also plays a contributing role. It is well known that oxygen deprivation can lead to hallucinations and may even contribute to the feeling of euphoria that is often reported. While the sample size available to researchers is limited, studies have indicated that individuals who reported a near-death experience during cardiac arrest also had lower levels of oxygen.
Researchers believe that oxygen deprivation could well result in people “seeing their lives flash before their eyes” or being transported to a place where they are surrounded by friends and relatives who have long since passed on. This remains just a theory, however, as the other available research seems to indicate that multiple factors contribute to the near-death experience, which include the aforementioned CO2 levels as well. It makes sense in this regard that near-death experiences are commonly reported by those resuscitated following a heart attack, as a heart attack occurs when blood is blocked from reaching the brain.
In the 21st Century, why do so many people still believe in the paranormal? David Robson discovers that there’s good reason we hold superstitions – and a few surprising benefits.
By David Robson via BBC Future
Soon after World War II, Winston Churchill was visiting the White House when he is said to have had an uncanny experience. Having had a long bath with a Scotch and cigar, he reportedly walked into the adjoining bedroom – only to be met by the ghost of Abraham Lincoln. Unflappable, even while completely naked, Churchill apparently announced: “Good evening, Mr President. You seem to have me at a disadvantage.” The spirit smiled and vanished.
His supposed contact with the supernatural puts Churchill in illustrious company. Arthur Conan Doyle spoke to ghosts through mediums, while Alan Turing believed in telepathy. Three men who were all known for their razor-sharp thinking, yet couldn’t stop themselves from believing in the impossible. You may well join them. According to recent surveys, as many as three quarters of Americans believe in the paranormal, in some form, while nearly one in five claim to have actually seen a ghost.
Intrigued by these persistent beliefs, psychologists have started to look at why some of us can’t shake off old superstitions and folk-lore. Their findings may suggest some hidden virtues to believing in the paranormal. At the very least, it should cause you to question whether you hold more insidious beliefs about the world.
Some paranormal experiences are easily explainable, based on faulty activity in the brain. Reports of poltergeists invisibly moving objects seem to be consistent with damage to certain regions of the right hemisphere that are responsible for visual processing; certain forms of epilepsy, meanwhile, can cause the spooky feeling that a presence is stalking you close by – perhaps underlying accounts of faceless “shadow people” lurking in the surroundings.
Out-of-body experiences, meanwhile, are now accepted neurological phenomena, while certain visual illusions could confound the healthy brain and create mythical beings. For example, one young Italian psychologist looked in the mirror one morning to find a grizzled old man staring back at him. His later experiments confirmed . . .