Monday, October 27, 2014

NEAR-DEATH EXPERIENCES EXPLAINED


brent.dunn@jefferson.kyschools.us
Tunnel
photo: iStockPhoto
Do you believe in life after death?
Many people believe in ghosts and heaven, and about three in 100 Americans report actually having near-death experiences. These typically include an awareness of being dead, out-of-body experiences, meeting dead people, entering tunnels of light, and so on.
But these are stories and anecdotes; what does science have to say?
A new article published in Trends in Cognitive Sciences by neuroscientist Dean Mobbs, of the University of Cambridge's Medical Research Council Cognition and Brain Sciences Unit, and Caroline Watt, of the University of Edinburgh, finds that "contrary to popular belief, research suggests that there is nothing paranormal about these experiences. Instead, near-death experiences are the manifestation of normal brain function gone awry, during a traumatic, and sometimes harmless, event."
Mobbs and Watt noted that many classic NDE symptoms are actually reported by people who were never in danger of dying in the first place. This suggests that the perception that one is near death is traumatic and disturbing enough to cause some of the experiences.
Researcher Susan Blackmore, author of Dying to Live: Near-Death Experiences (Prometheus Books, 1993), notes that many NDEs (such as euphoria and the feeling of moving toward a tunnel of white light) are common symptoms of oxygen deprivation in the brain.
The new paper also discussed something called "walking corpse" syndrome, named after French neurologist Jules Cotard. Co-author Watt told Discovery News, "The sufferer feels that he or she is dead, even though not actually near death. It can be associated with trauma and some illnesses. It's not fully understood why individuals suffer from Cotard syndrome, but one possibility is that it's the brain's attempt to make sense of the strange experiences that the patient is having.
"This is relevant to NDEs because the near-death experience may also arise out of an attempt to interpret unusual physiological and psychological experiences, and the NDE includes the perception that one is not alive in the normal sense of the word."
Watt's research also busts another myth: that people have "returned from the dead" -- if by dead you mean clinical brain death.
No one has survived true clinical death (which is why the experiences are called near-death). Many people have been revived after their heart stopped for short periods of time -- around 20 minutes or more -- but anyone revived from brain death would be permanently and irreparably brain damaged and certainly unable to report their experiences.
"The idea of surviving clinical brain death is mythical," Watt said. "NDEs are sometimes reported after a person experiences some of the preliminary 'stages' of death -- for instance, when the heart stops beating for a while and the person is then revived. I think it's curious, however, that a survey has shown that 82 percent of individuals who have survived being actually near death do not report a near-death experience. That would seem to undermine the idea that these experiences give a glimpse into life after death."
Watt believes that near-death experiences hold an enduring fascination for people because they like the idea that humans survive bodily death.
"Some people find this a comforting idea," Watt said, "because it suggests we are not simply like other biological organisms on our planet."
The fact that near-death experiences can be chemically induced and explained by neurological mechanisms suggests a natural -- instead of supernatural -- cause.

Monday, October 20, 2014

FLY PARASITE TURNS HONEY BEES INTO 'ZOMBIES' The parasites that cause the transformation may provide a clue to the mysterious colony collapse disorder


American scientists have discovered that a fly parasite can turn honey bees into confused zombies before killing them, in an advance that could offer new clues to why bee colonies are collapsing.

So far, the parasite has only been detected in honey bees in California and South Dakota, American researchers reported in the open access science journal PLoS ONE this week.


But if it turns out to be an emerging parasite, that "underlines the danger that could threaten honey bee colonies throughout North America," said the study led by San Francisco State University professor of biology John Hafernik.

Hafernik made the discovery by accident, when he foraged some bees from outside a light fixture at the university to feed to a praying mantis he'd brought back from a field trip.

"But being an absent-minded professor, I left them in a vial on my desk and forgot about them. Then the next time I looked at the vial, there were all these fly pupae surrounding the bees," he said.

Soon, the bees began to die, but not in the usual way by sitting still and curling up. These bees kept trying to move their legs and get around, but they were too weak, said lead author Andrew Core, a graduate student in Hafernik's lab.

"They kept stretching them out and then falling over," said Core. "It really painted a picture of something like a zombie."

Further study showed that bees that left their hives at night were most likely to become infected with the fly parasite, identified as Apocephalus borealis.

Once bees were parasitized by the fly, they would abandon their hives and congregate near lights, a very unusual behavior for bees.


"When we observed the bees for some time -- the ones that were alive -- we found that they walked around in circles, often with no sense of direction," said Core.

The parasite lays its eggs in the bee's abdomen. About a week after the bee dies, the fly larvae push their way into the world, often exiting from between the bee's head and mid-section.

The research, which has also confirmed that the same flies have been parasitizing bumblebees, won local excellence awards when it was first presented last year.

Next, the team hopes to find out more about where the parasitization is taking place, and whether the "zombie bees" leave the colony of their own accord or if their disease is sensed by comrades who then push them out.

Researchers plan to use tiny radio tags and video monitoring to find clues to the mystery.

"We don't know the best way to stop parasitization, because one of the big things we're missing is where the flies are parasitizing the bees," Hafernik said.

"We assume it's while the bees are out foraging, because we don't see the flies hanging around the bee hives. But it's still a bit of a black hole in terms of where it's actually happening."

Experts have theorized that the huge die-off of bees worldwide since 2006, a major threat to crops that depend on the honey-making insects for pollination, is not due to any one single factor.

Parasites, viral and bacterial infections, pesticides, and poor nutrition resulting from the impact of human activities on the environment have all played a role in the decline.

The mysterious decimation of bee populations in the United States, Europe, Japan and elsewhere in recent years threatens agricultural production worth tens of billions of dollars.

Monday, October 13, 2014

FYI: Could Scientists Really Create a Zombie Apocalypse Virus?


Dead Head Infectious proteins called prions could shut down parts of the brain and leave others intact, creating a zombie. iStock
Maybe, but it’s not going to be easy. In West African and Haitian vodou, zombies are humans without a soul, their bodies nothing more than shells controlled by powerful sorcerers. In the 1968 film Night of the Living Dead, an army of shambling, slow-witted, cannibalistic corpses reanimated by radiation attack a group of rural Pennsylvanians. We are looking for something a little in between Haiti and Hollywood: an infectious agent that will render its victims half-dead but still-living shells of their former selves.

See our gallery of real live zombies in nature.
An effective agent would target, and shut down, specific parts of the brain, says Steven C. Schlozman, an assistant professor of psychiatry at Harvard University and author of The Zombie Autopsies, a series of fictional excerpts from the notebooks of “the last scientist sent to the United Nations Sanctuary for the study of ANSD,” a zombie plague. Schlozman explained to PopSci that although the walking dead have some of their motor skills intact—walking, of course, but also the ripping and tearing necessary to devour human flesh—the frontal lobe, which is responsible for morality, planning, and inhibiting impulsive actions (like taking a bite out of someone), is nonexistent. The cerebellum, which controls coordination, is probably still there but not fully functional. This makes sense, since zombies in movies are usually easy to outrun or club with a baseball bat.
The most likely culprit for this partially deteriorated brain situation, according to Schlozman, is as simple as a protein. Specifically, a proteinaceous infectious particle, a prion. Not quite a virus, and not even a living thing, prions are nearly impossible to destroy, and there’s no known cure for the diseases they cause.
The first famous prion epidemic was discovered in the early 1950s in Papua New Guinea, when members of the Fore tribe were found to be afflicted with a strange tremble. Occasionally a diseased Fore would burst into uncontrollable laughter. The tribe called the sickness “kuru,” and by the early ’60s doctors had traced its source back to the tribe’s cannibalistic funeral practices, including brain-eating.
Prions gained notoriety in the 1990s as the infectious agents that brought us bovine spongiform encephalopathy, also known as mad cow disease. When a misshapen prion enters our system, as in mad cow, our mind develops holes like a sponge. Brain scans from those infected by prion-based diseases have been compared in appearance to a shotgun blast to the head.
Now, if we’re thinking like evil geniuses set on global destruction, the trick is going to be attaching a prion to a virus, because prion diseases are fairly easy to contain within a population. To make things truly apocalyptic, we need a virus that spreads quickly and will carry the prions to the frontal lobe and cerebellum. Targeting the infection to these areas is going to be difficult, but it’s essential for creating the shambling, dim-witted creature we expect.
Jay Fishman, director of transplant infectious diseases at Massachusetts General Hospital in Boston, proposes using a virus that causes encephalitis, an inflammation of the brain’s casing. Herpes would work, and so would West Nile, but attaching a prion to a virus is, Fishman adds, “a fairly unlikely” scenario. And then, after infection, we need to stop the prion takeover so that our zombies don’t go completely comatose, their minds rendered entirely useless. Schlozman suggests adding sodium bicarbonate to induce metabolic alkalosis, which raises the body’s pH and makes it difficult for proteins like prions to proliferate. With alkalosis, he says, “you’d have seizures, twitching, and just look awful like a zombie."

Tuesday, October 7, 2014

Hooking a 9-Volt Battery To Your Brain Improves Your Video Game Skills, Researcher Finds

(But don't try this at home)



9-Volt Battery Wikimedia Commons
We’ve already seen how magnets hovering close to a person’s head can affect speech, behavior and learning patterns. Now it appears zapping your brain with a 9-volt battery will make youbetter at video games, at least according to one researcher. Don’t try this yourself, though.
Neuroscientists at the University of New Mexico asked volunteers to play a video game called “DARWARS Ambush!”, developed to help train American military personnel. Half of the players received 2 milliamps of electricity to the scalp, using a device powered by a simple 9-volt battery, and they played twice as well as those receiving a much tinier jolt. The DARPA-funded study suggests direct current applied to the brain could improve learning.
This type of brain stimulation, called transcranial direct current stimulation (tDCS), is controversial but could show promise for treatment of various neurological disorders and cognitive impairments. Click through to Nature News for a thorough overview.
It’s different from transcranial magnetic stimulation, in which a magnetic coil running at high voltage is positioned close to the head. The magnets stimulate electrical responses in the brain. Transcranial direct current stimulation is just what it sounds, applying the current directly to the brain.
We’ve been hearing quite a lot about these methods lately, and the scientific literature indicates the fields — tDCS in particular — are experiencing a revival, Nature News points out. Scientists hope the methods could be used to treat depression, post-traumatic stress disorder, stroke and autism, as well as to improve learning by increasing the brain’s plasticity.
Researchers are beginning to understand how an external electrical current affects brain function, including by inducing changes to the flow of electricity across neurons and increasing the expression of certain synapse proteins.
Apparently, it takes very little electricity to do all this. But please, don’t start hooking up 9-volt batteries to your brain — leave that to the scientific studies.