When Sleeping Turns Deadly and Other Strange Tales fromScientific American MIND

By Ingrid Wickelgren | June 11, 2012 |  

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The July/August issue of Scientific American Mind made its debut online late last week. Here I divulge some of the more surprising and useful lessons from its pages.

Dozing Dangerously

Sleepwalking is one of the strangest phenomena I have ever witnessed. Despite its name, it doesn’t resemble any other kind of sleep I’ve seen. To me, it appears as if an odd imposter has temporarily inhabited the body of someone I know. The person’s eyes are open. He or she gets up, strolls or scampers around, and can hug me or grab a drinking glass. He may even talk to me. The slumbering human really seems awake—until it dawns on me that his behavior is distinctly erratic. The person may respond to me—say, take a drink when I give him a glass of juice—but in an odd manner, say, gulping the liquid as if in a huge hurry. His eyes might open wide as if he’s panic-stricken, but the cause of the panic is nowhere to be seen. And he may do nonsensical things such as pouring liquid from a cup into the trashcan.

In 1846, Albert Tirrell was acquitted of the murder of Maria Bickford because he was sleepwalking. By National Police Gazette via Wikimedia Commons.

When a person is sleepwalking, as we report in the current issue of the magazine, the brain is kind of half awake. Some parts, those involved in talking and walking, are operational. But other parts, those involved in reasoning and self-control, are pretty much in lala land, explaining why the person’s actions make no sense. Sleepwalking is apparently common (and usually benign) in children. But in some adults it turns violent (see “Are Sleepwalking Killers Conscious?” by Francesca Siclari, Guilio Tononi and Claudio Bassetti). In rare cases, sleepwalkers have committed murder, and at least half of those with sleep disorders exhibit less serious forms of unintentional violence. In some instances, the murderous sleeper has been acquitted (see illustration). But questions of culpability remain. Was it a strange imposter’s fault? Probably, but the loss of control is frightening for all concerned.

On the plus side, researchers are uncovering the biological roots of such odd actions in hopes of developing treatments. In the process, they are also gleaning clues to the origins of consciousness.

Microbial Madness

Speaking of brains subverted by demons, consider the influence of gut microbes. One parasite co-opts the intentions of mice such that they are drawn to cats, which, of course, then consume the brainwashed rodents (see “Microbes Manipulate Your Mind,” by Moheb Costandi). In humans, gut microbes can subtly change our moods and emotional states. The “brains” in our guts—a combination of 500 microorganisms that seems to vary from one person to the next—may even explain differences between people in personality as well as disparities between us in symptoms of psychiatric illnesses.

Notably, our bodies’ microbial inhabitants might make us more or less able to withstand stress. Colicky babies, we report, seem to have a less diverse array of germs in their gut, and seem to be predisposed to stress later on. But as adults, we might also be able to deliberately colonize ourselves for better mental health. Early data suggest that probiotics might be able to quell anxiety. Whenever I feel overwhelmed, I am going to make a point of indulging in live-culture yogurt, and not just for the calcium. Taking stress down a notch, after all, can improve productivity.

Inspiring Ingenuity

Research unraveling the roots of creativity might be even more beneficial to my performance, however. An article in this issue suggests that creativity is not unique to unusually gifted individuals such as Einstein, Picasso or Mozart (see “Put Your Creative Brain to Work,” by Evangelia G. Chrysikou). Instead, its roots lie in mental processes such as decision making, language and memory that all of us possess. In the first stage of the creative process, the generation of ideas, it is best to keep an open mind. In the brain, this translates into lower activity in the cognitive control regions of the prefrontal cortex. But later in the process, when you have to evaluate your options, the brain’s cognitive filter needs to go online again. So different brain states are optimal for different parts of a creative endeavor.

Taking a break at the office can spur creativity. Courtesy of Robert Gaal via Flickr.

Putting yourself into an innovative mindset can be as simple as doing something backwards–or engaging in any exercise that shakes up your typical way of thinking. Prepare a sandwich by using the bread to scoop up the insides (or some other crazy method). Think of nonstandard uses for a roll of toilet paper. (Can its cardboard innards be used to protect something?) Describe an object in terms of its parts rather than its use. My tape dispenser at the office is a piece of hard plastic that curves up at the ends with a hole in the middle that can accommodate a plastic circular piece that spins around. It also has a serrated metal piece at one end. Having revised my definition of that object, I should be able to generate more creative thoughts about other things.

If I am still short on ideas, I can try enlisting my subconscious. To do that, I need to put my conscious mind out of commission by not thinking about the problem. Instead, I can sleep on it, let my mind wander or just do something completely different for a while.

If I really want to break boundaries, I will also need to do something that is hard for most people: let go of my fear. Being brave enough to dismiss safe and proven paths or solutions is a basic requirement for innovation. Those of us who trod down well-worn avenues may find success in our own limited way. But the folks willing to whack a trail through the bush in uncharted territory are the ones with a real chance at reinventing the world.

About the Author: Ingrid Wickelgren is an editor at Scientific American Mind, but this is her personal blog at which, at random intervals, she shares the latest reports, hearsay and speculation on the mind, brain and behavior. Follow on Twitter @iwickelgren.

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The views expressed are those of the author and are not necessarily those of Scientific American.

Infectious Selflessness: How an Ant Colony Becomes a Social Immune System

Ants work together to battle a deadly fungus by diluting the infection across the colony

By Ferris Jabr  | April 3, 2012

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SOCIAL IMMUNITY An ant colony can act as one giant immune system when battling a pathogen, like an infectious fungus.Image: Luke Elstad, Wikimedia Commons

In the 2011 blockbuster thriller Contagion, a virus infects and kills 26 million people around the world. But even those who evade the virus are infected with something else:crippling fear. To contain the outbreak, the military imposes a quarantine. People stay indoors, refusing to interact with anyone outside their families. Touching anyone or anything becomes a risk, because the virus lingers everywhere.

Ants do things differently. When a deadly fungus infects an ant colony, the healthy insects do not necessarily ostracize their sick nest mates. Instead, they welcome the contagious with open arms—or, rather, open mouths—often licking their neighbors to remove the fungal spores before the pathogens sprout and grow. Apparently, such grooming dilutes the infection, spreading it thinly across the colony. Instead of leaving their infected peers to deal with the infection on their own and die, healthy ants share the burden, deliberately infecting everyone in the colony with a tiny dose of fungus that each individual's immune system can clear on its own. Such "social immunization" also primes the immune systems of healthy ants to battle the infection. These are the conclusions of a new study in the April 3 issue of PLoS Biology.

When you encounter a particular pathogen—a virus, a fungus—for the first time, your immune system has to learn how to deal with it. The second time you meet the same pathogen, your immune system is ready—it has developed some resistance. Researchers have found that when some members of an ant colony are exposed to a pathogen for the first time, all members of that colony—even the ones that were not initially infected—build resistance to the pathogen. How this happens was never clear.

To investigate the mystery, Sylvia Cremer of the Institute of Science and Technology in Austria and her colleagues studied Lasius neglectus, a rather common-looking ant that forms supercolonies, and Metarhizium anisopliae, a parasitic fungus that feeds on and kills many insects. Once the fungal spores settle on an insect's body, they germinate and penetrate the exoskeleton with rootlike structures called hyphae. Eventually the fungus sucks out all the nutrients from the insect and encrusts its emptied husk in what looks like green mold.

To interrupt the pathogen's life cycle, some ants lick fungal spores off of others. As the ants groom one another, bacteria on their skin—as well as specialized glands in the mouth called infrabuccal pockets—kill most of the spores that they lap up. Later, the ants spit out a compacted ball of dead spores. But Cremer and her colleagues suspected that not all of the spores are killed and that, by tending to infected peers, healthy ants end up with some spores on their bodies.

Cremer and her teammates tested these hunches by first tagging M. anisopliae spores with a protein that glows red under ultraviolet light and subsequently exposing 15 ants to the signature spores. Two days later the researchers dissected the ants under a microscope and detected the blushing spores on 17 of 45 ants that they had not directly exposed to the fungus. Cremer concluded that these ants must have picked up the spores by grooming their infected nest mates. The infection had rippled through the colony. When the researchers dissected the ants and placed their body parts in agar plates, fungi grew on 64 percent of the ants that had not been directly exposed to the spores—an even larger portion of the colony than the scientists had first detected with UV light.

"Even though 60 to 80 percent of nest mates contracted the disease, only about 2 percent of the ants died," Cremer explains. "Such low-level infections were actually beneficial because they saved the directly exposed ants and built up resistance in the healthy ants."

When Cremer analyzed the gene activity of ants that picked up spores from infected peers, she found that genes coding for antifungal proteins, as well as more general immune proteins, were more active than usual. Removing fungal spores from a peer seems to prime the immune system to battle any collateral infections. When Cremer prevented healthy ants from touching infected ants, the infection did not spread, the uninfected nestmates did not rev up their immune systems and many of the lone ants died. Cremer also observed that healthy ants are especially attentive to sick nest mates in the first two days after infection, which makes sense because if the spores are not removed within that period, it is usually too late to prevent full-blown infection and death.

Cremer and her colleagues think that the newly observed interactions between healthy and sick ants—as well as the genetic evidence of increased immune responses—explain how an entire ant colony develops resistance to a pathogen, even if only some of the ants are directly exposed to that pathogen. Although each insect has its own immune system, ants seem to have evolved a second immune system—a colony-wide immune response to infection. To thwart contagion, ants embrace it.

Rebeca Rosengaus of Northeastern University was impressed with the variety of experiments and analyses in the new study, which she says "provides further support that social immunity is a real phenomenon, not only in ants, but also in termites and probably eusocial wasps and bees, too." In earlier work Rosengaus discovered that termites exposed to a fungus warn one another by "essentially having a seizure"—hopping around like crazy and banging their heads against their nest walls to keep healthy peers away. She also found evidence that ants spread immunity to bacterial infections by transmitting immune proteins in droplets of food passed from one ant's mouth to another. "It goes against what you might think. Because there are so many individuals living so closely together, if one gets sick, chances are someone else would get sick, but through social immunization the entire colony seems to be doing better."