Discover Magazine | The Brain

The Brain: Sewing Audio to Video, and Rubber Hands Onto People

Thu, 15 Dec 2011 14:05:00 -0500

I don’t usually stream Netflix onto my television to probe the  inner workings of my mind, but it had that effect not long ago.  While I was catching an old episode of Law & Order: Criminal Intent, the actors’ voices lagged a fraction of a second behind the movement  of their mouths, making me so disoriented it completely ruined the show. Soon my irritation turned to puzzlement, and some self-observation allowed me to track my frustration to a precise source. I didn’t care that the ominous soundtrack rose half a second late when Vincent D’Onofrio and Kathryn Erbe crept into the subway tunnel where they  were about to find a body. I didn’t care that the show’s trademark duh-dung! sound marking a new scene was still duh-dung-ing after the scene started. It was only when people talked that I went batty. I would watch the characters speak, and then I’d switch to listening to them, and then I’d watch them speak again. I just couldn’t meld the two streams of information in my head.

Thanks to Netflix, I was confronted with one of the most crucial tricks that the human brain uses to make sense of the world: combining input from all five senses into a single, coherent experience, updated many times a second in virtually real time. Because the techniques our brains use to meld the senses are far from perfect, it turns out, we can fall prey to a variety of illusions—and to maddening confusion when Netflix delivers audio and video out of sync.

One of the most famous such illusions is known as the McGurk Effect, named for its discoverer, Harry McGurk, a developmental psychologist at the University of Surrey in England. In the 1970s he filmed people repeatedly making the sound ga. Then he had a new audio track laid over the film so that ga was replaced with the sound ba. The new audio and video were perfectly in sync. Many people who watched the movie were sure that the speakers were actually saying da, a different syllable entirely. If they closed their eyes, they heard the correct ba. When they opened their eyes, it became da again. (If you don’t know about the McGurk Effect, you may want to experience it via this very impressive video)...

The Brain: Maybe You Do Need a Hole in Your Head—to Let the Medicine In

Tue, 15 Nov 2011 12:25:00 -0500

Neuroscientists these days regularly make spectacular discoveries about how the brain gets sick. They know much more today about brain cancer, Alzheimer’s disease, Parkinson’s disease, and a host of other neurological disorders than they did just a few years ago. And from such discoveries come all sorts of encouraging possibilities for treating or even curing these diseases. If  only we could break down some rogue protein or bind a drug to  a troublesome receptor, it seems as if all would be well. There’s just one little hitch: Even if scientists invented the perfect cure, they  probably couldn’t get it into the brain to do its work.

Drugs can cross easily out of the bloodstream into most organs of the body. The brain is a glaring exception because it is protected by an intricate shield known as the blood-brain barrier. The blood-brain barrier serves a vital function: It keeps our brains free for the most part from infections or toxins that find their way into other parts of the body. Unfortunately, the brain’s barrier also gets in the way of most medicines that could help heal it. Neurologists sometimes open up the skull and inject drugs directly. That brute-force approach can work in an emergency, but it is hardly a practical solution for people who need to take drugs every day at home.

There is reason for hope that the blood-brain barrier will not block medicine’s path forever, though. Some scientists are working on ways to penetrate it—either by sneaking drugs through the barrier or by temporarily opening channels through which the drugs can pass...

The Brain: The Language Fossils Buried in Every Cell of Your Body

Mon, 17 Oct 2011 14:25:00 -0400

It is a shame that grammar leaves no fossils behind. Few things have been more important to our evolutionary history than language. Because our ancestors could talk to each other, they became a powerfully cooperative species. In modern society we are so submerged in words—spoken, written, signed, and texted—that they seem inseparable from human identity. And yet we cannot excavate some fossil from an Ethiopian hillside, point to a bone, and declare, “This is where language began.”

Lacking hard evidence, scholars of the past speculated broadly about the origin of language. Some claimed that it started out as cries of pain, which gradually crystallized into distinct words. Others traced it back to music, to the imitation of animal grunts, or to birdsong. In 1866 the Linguistic Society of Paris got so exasperated by these unmoored musings that it banned all communication on the origin of language. Its English counterpart felt the same way. In 1873 the president of the Philological Society of London declared that linguists “shall do more by tracing the historical growth of one single work-a-day tongue, than by filling wastepaper baskets with reams of paper covered with speculations on the origin of all tongues.”

A century passed before linguists had a serious change of heart. The change came as they began to look at the deep structure of language itself. MIT linguist Noam Chomsky asserted that the way children acquire language is so effortless that it must have a biological foundation. Building on this idea, some of his colleagues argued that language is an adaptation shaped by natural selection, just like eyes and wings. If so, it should be possible to find clues about how human language evolved from grunts or gestures by observing the communication of our close primate relatives.

This line of thinking raised an exciting possibility: Perhaps language left a fossil record after all—not in buried bones, but in our DNA. Yet for years biologists could not find a single gene involved in language...

The Brain: "I See," Said the Blind Man With an Artificial Retina

Thu, 15 Sep 2011 11:50:00 -0400

For 100 million people around the globe who suffer from macular degeneration and other diseases of the retina, life is a steady march from light into darkness. Until recently some types of retinal degeneration seemed as inevitable as the wrinkling of skin or the graying of hair—only far more terrifying and debilitating. But recent studies offer hope that eventually the darkness may be lifted. Some scientists are trying to inject signaling molecules into the eye to stimulate light-collecting photoreceptor cells to regrow. Others want to deliver working copies of broken genes into retinal cells, restoring their function. And a number of researchers are taking a fundamentally different, technology-driven approach to fighting blindness. They seek not to fix biology but to replace it, by plugging cameras into people’s eyes...

Image: human retina. Source: iStockphoto.

The Brain: A Body Fit for a Freaky-Big Brain

Tue, 26 Jul 2011 13:30:00 -0400

In 1758 the Swedish taxonomist Carolus Linnaeus dubbed our species Homo sapiens, Latin for “wise man.” It’s a matter of open debate whether we actually live up to that moniker. If Linnaeus had wanted to stand on more solid ground, he could have instead called us Homo megalencephalus: “man with a giant brain.”

Regardless of how wisely we may use our brains, there’s no disputing that they are extraordinarily big. The average human brain weighs in at about three pounds, or 1,350 grams. Our closest living relatives, the chimpanzees, have less than one-third as much brain—just 384 grams. And if you compare the relative size of brains to bodies, our brains are even more impressive.

As a general rule, mammal species with big bodies tend to have big brains. If you know the weight of a mammal’s body, you can make a fairly good guess about how large its brain will be. As far as scientists can tell, this rule derives from the fact that the more body there is, the more neurons needed to control it. But this body-to-brain rule isn’t perfect. Some species deviate a little from it. A few deviate a lot. We humans are particularly spectacular rule breakers. If we were an ordinary mammal species, our brains would be about one-sixth their actual size...

Image courtesy of Byron Eggenshwiler.

The Brain: A Tiny Key to a Terrible Lock

Thu, 16 Jun 2011 12:30:00 -0400

For tens of millions of Americans, pain is not just an occasional  nuisance—a stubbed toe, a paper cut—but a constant and torturous companion. Chronic pain can be focused on an arthritic knee or a bad back, diffused throughout the body, or even located virtually in an amputated limb. It can linger for years. And it can transform the world so that merely the light brush of a finger is an agonizing experience. The daily devastation can be so intense that people with chronic pain are up to six times as likely as those who are pain-free to report suicidal thoughts.

Despite the toll, chronic pain has been relatively neglected by  doctors. Perhaps that’s because it seems less real to them than other, more tangible medical disorders. With no equivalent of a stethoscope  or thermometer to measure pain objectively, they have had to rely  entirely on their patients’ testimony.

As neuroscientists learn more about the biological basis of pain, the situation is finally beginning to change. Most remarkably, unfolding research shows that chronic pain can cause concrete, physiological changes in the brain. After several months of chronic pain, a person’s brain begins to shrink. The longer people suffer, the more gray matter they lose.

With that bad news, though, comes a message of hope. In documenting the damage that chronic pain causes, neuroscientists are also beginning to decipher how it comes to exist in the first place. Those insights suggest better treatments and cures...

Image credit: Bryon Eggenschwiler.

The Brain Is Made of Its Own Architects

Tue, 17 May 2011 16:50:00 -0400

In the 1940s, the Nobel prize–winning neurobiologist Roger Sperry performed some of the most important brain surgeries in the history of science. His patients were newts.

Sperry started by gently prying out newts’ eyes with a jeweler’s forceps. He rotated them 180 degrees and then pressed them back into their sockets. The newts had two days to recover before Sperry started the second half of the procedure. He sliced into the roof of each newt’s mouth and made a slit in the sheath surrounding the optic nerve, which relays signals from the eyes to the brain. He drew out the nerve, cut it in two, and tucked the two ragged ends back into their sheath.

A month later Sperry’s subjects could see again. The experiment revealed that nerve cells, or neurons, possess a tremendous capacity for wiring themselves. Neurons grow branches known as dendrites for receiving signals, and sprout long outgrowths called axons to relay the signals to other neurons. Axons in particular can travel spectacular distances to reach astonishingly precise targets. They can snake through the brain’s dense thicket, pushing past billions of other neurons, in order to form tight connections, or synapses, with just the right partners.

To better treat wiring disorders, scientists are trying to understand how neurons form circuits. But almost 70 years after Sperry’s newt surgery, the wiring question remains one of the deepest mysteries in neuroscience. One reason why is that the wiring problem is actually a series of problems, each of which our neurons may solve in several ways...

Image: iStockphoto

The Brain: Memories Are Crucial for Looking Into the Future

Sun, 24 Apr 2011 13:35:00 -0400

One day not long ago a 27-year-old woman was brought to the  Tel Aviv Sourasky Medical Center, sleepy and confused. Fani Andelman, a neuropsychologist at the center, and colleagues gave the woman a battery of psychological tests to judge her state of mind. At first the woman seemed fine. She could see and speak clearly. She could understand the meaning of words and recall the faces of famous people. She could even solve logic puzzles, including a complex test that required her to plan several steps ahead. But her memory had holes. She could still remember recent events outside her own life, and she could tell Andelman details of her life up to 2004. Beyond that point, however, her autobiography was in tatters. The more doctors probed her so-called episodic memory—the sequential recollection of personal events from the past—the more upset she became. As for envisioning her personal future, that was a lost cause. Asked  what she thought she might be doing anytime beyond the next day, she couldn’t tell them anything at all. The patient, Andelman realized, hadn’t just lost her past; she had lost her future as well. It was impossible for her to imagine traveling forward in time. During her examination, the woman offered an explanation for her absence of foresight. “I barely know where I am,” she said. “I don’t picture myself in the future. I don’t know what I’ll do when I get home. You need a base to build the future.” The past and future may seem like different worlds, yet the two are intimately intertwined in our minds. In recent studies on mental time travel, neuroscientists found that we use many of the same regions of the brain to remember the past as we do to envision our future lives. In fact, our need for foresight may explain why we can form memories in the first place. They are indeed “a base to build the future.” And together, our senses of past and future may be crucial to our species’ success. Endel Tulving, a neuroscientist at the University of Toronto, first proposed a link between memory and foresight in 1985. It had occurred to him as he was examining a brain-injured patient. “N.N.,” as the man was known, still had memories of basic facts. He could explain how to make a long-distance call and draw the Statue of Liberty. But he could not recall a single event from his own life. In other words, he had lost his episodic memory. Tulving and his colleagues then discovered that N.N. could not imagine the future. “What will you be doing tomorrow?” Tulving asked him during one interview. After 15 seconds of silence, N.N. smiled faintly. “I don’t know,” he said. “Do you remember the question?” Tulving asked. “About what I’ll be doing tomorrow?” N.N. replied. “Yes. How would you describe your state of mind when you try to think about it?” N.N. paused for a few more seconds. “Blank, I guess,” he said. The very concept of the future, seemed meaningless to N.N. “It’s like being in a room with nothing there and having a guy tell you to go find a chair,” he explained.

On the basis of his study of N.N., Tulving proposed that projecting ourselves into the future requires the same brain circuitry we use to remember ourselves in the past. Over the past decade, as scientists have begun to use fMRI scanners to probe the activity of the brain, they have found support for his hypothesis. Last year, for example, Tulving and his colleagues had volunteers lie in an fMRI scanner and imagine themselves in the past, present, and future. The researchers saw a number of regions become active in the brains of the volunteers while thinking of the past and future, but not the present...

The Brain: The Trouble With Teens

Thu, 24 Mar 2011 15:20:00 -0400

Teenagers are a puzzle, and not just to their parents. When kids pass from childhood to adolescence their mortality rate doubles, despite the fact that teenagers are stronger and faster than children as well as more resistant to disease. Parents and scientists alike abound with explanations. It is tempting to put it down to plain stupidity: Teenagers have not yet learned how to make good choices. But that is simply not true. Psychologists have found that teenagers are about as adept as adults at recognizing the risks of dangerous behavior. Something else is at work.

Scientists are finally figuring out what that “something” is. Our brains have networks of neurons that weigh the costs and benefits of potential actions. Together these networks calculate how valuable things are and how far we’ll go to get them, making judgments in hundredths of a second, far from our conscious awareness. Recent research reveals that teen brains go awry because they weigh those consequences in peculiar ways.

Neuroscientist B. J. Casey and her colleagues at the Sackler Institute of the Weill Cornell Medical College believe the unique way adolescents place value on things can be explained by a biological oddity. Within our reward circuitry we have two separate systems, one for calculating the value of rewards and another for assessing the risks involved in getting them. And they don’t always work together very well...

The Brain: Seeing the Person Behind the Face

Wed, 19 Jan 2011 13:45:00 -0500

Imagine that an eccentric psychologist accosts you. In his hand is a piece of paper with 20 pictures of roses. One of the pictures shows a rose in the flower bed you just passed, he says, and he asks you to pick its picture out from his lineup. The challenge would seem absurd—but if you were to change the roses to faces, nearly everyone could meet it. Most of us have a powerful ability to recognize faces, and yet we hardly ever take note of it. We can commit a face to memory with a single viewing, and even if we see that face only once its memory can stay fresh for years. The faces we remember so easily may differ only in subtle tweaks of geometry: the ratio of distances between different landmarks such as the eyes and the mouth, for example. A small fraction of people, however, cannot recognize faces—even the faces of their parents, spouses, and children. Prosopagnosia, as this condition is known, can affect people from birth or be triggered later in life by injuries to the brain. It strikes an estimated 2 percent of Americans and is often accompanied by other types of recognition impairments, including difficulty recognizing places and objects, such as cars. Despite the millions of people who suffer from prosopagnosia, it remains an obscure disorder, probably due to the skill with which face-blind people quietly compensate for their condition...

The Brain: Is Music for Wooing, Mothering, Bonding—or Is It Just "Auditory Cheesecake"?

Wed, 22 Dec 2010 10:25:00 -0500

Image: iStockphoto

See more writing from Discover blogger Carl Zimmer in his new ebook, Brain Cuttings: Fifteen Journeys Through the Mind. For more information, visit his website.

When Charles Darwin listened to music, he asked himself, what is it for? Philosophers had pondered the mathematical beauty of music for thousands of years, but Darwin wondered about its connection to biology. Humans make music just as beavers build dams and peacocks show off their tail feathers, he reasoned, so music must have evolved. What drove its evolution was hard for him to divine, however. “As neither the enjoyment nor the capacity of producing musical notes are faculties of the least direct use to man in reference to his ordinary habits of life, they must be ranked among the most mysterious with which he is endowed,” Darwin wrote in 1871.

Today a number of scientists are trying to solve that mystery by looking at music right where we experience it: in the brain. They are scanning the activity that music triggers in our neurons and observing how music alters our biochemistry. But far from settling on a single answer, the researchers are in a pitched debate over music. Some argue that it evolved in our ancestors because it allowed them to have more children. Others see it as merely a fortunate accident of a complex brain...

The Brain: The "Router" in Your Head—a Bottleneck of Processing

Mon, 15 Nov 2010 14:25:00 -0500

Pop quiz: what is 357 times 289? no pencils allowed. no calculators. Just use your brain.

Got an answer yet? Got it now? How about now? Chances are you still don’t. As you solved the problem one step at a time, you lost track of the numbers. Maybe you tried to start over, lost track again, and eventually gave up in frustration before you could discover that the answer was 103,173. I used a calculator to get that, I confess...

Our mutual failure is absurd. The brain is, in the words of neuroscientist Floyd Bloom, “the most complex structure that exists in the universe.” Its trillions of connections let it carry out all sorts of sophisticated computations in very little time. You can scan a crowded lobby and pick out a familiar face in a fraction of a second, a task that pushes even today’s best computers to their limit. Yet multiplying 357 by 289, a task that demands a puny amount of processing, leaves most of us struggling.

For psychologists, this kind of mental shortcoming is like a crack in a wall. They can insert a scientific crowbar and start to pry open the hidden life of the mind. The fact that we struggle with certain simple tasks speaks volumes about how we are wired. It turns out the evolution of our complex brain has come at a price: Sometimes we end up with a mental traffic jam in there...

The Brain: "Ringing in the Ears" Actually Goes Much Deeper Than That

Wed, 27 Oct 2010 12:00:00 -0400

See Carl Zimmer's new ebook, Brain Cuttings, available at Amazon, Barnes and Noble, and carlzimmer.com.

In some of the world’s oldest medical texts—papyrus scrolls from ancient Egypt, clay tablets from Assyria—people complain about noise in their ears. Some of them call it a buzzing. Others describe it as whispering or even singing. Today we call such conditions tinnitus. In the distant past, doctors offered all sorts of strange cures for it. The Assyrians poured rose extract into the ear through a bronze tube. The Roman writer Pliny the Elder suggested that earthworms boiled in goose grease be put in the ear. Medieval Welsh physicians in the town of Myddfai recommended that their patients take a freshly baked loaf of bread ($) out of the oven, cut it in two, “and apply to both ears as hot as can be borne, bind and thus produce perspiration, and by the help of god you will be cured.”

Today tinnitus continues to resist medicine’s best efforts, despite being one of the more common medical disorders. Surveys show that between 5 and 15 percent of people say they have heard some kind of phantom noise for six months or more; some 1 to 3 percent say tinnitus lowers their quality of life. Tinnitus can force people to withdraw from their social life, make them depressed, and give them insomnia.

Some modern doctors prescribe drugs like lidocaine. Others offer patients cognitive therapy. Some have people listen to certain sounds, others apply magnetic pulses to the brain and even implant electrodes in the brain stem. Although many treatments have shown some promise, none is consistently effective. Recent research suggests why: Tinnitus is a lot more complicated than just a ringing in the ears. It is more like a ringing across the brain...

The Brain: The Places in the Brain Where Space Lives

Tue, 21 Sep 2010 10:50:00 -0400

The great philosopher Immanuel Kant believed that nothing matters more to our existence than space. Every experience we have—from the thoughts in our heads to the stars we see wheeling through the sky—makes sense only if we can assign it a location. “We never can imagine or make a representation to ourselves of the non-existence of space,” he wrote in 1781.

The nonexistence of space may certainly be hard to imagine. But for some people it is part of everyday life. Strokes can rob us of space. So can brain injuries and tumors. In 1941, neurologists Andrew Paterson and O. L. Zangwill, working in Edinburgh, Scotland, published an account of a 34-year-old patient who had been hit in the head by a mortar fragment. The injury wiped out his sense of the left half of his world. Paterson and Zangwill described how the man “consistently failed to appreciate doors and turnings on his left-hand side even when he was aware of their presence.” He also “neglected the left-hand side of a picture or the left-hand page of a book despite the fact that his attention was constantly being drawn to the oversight.” The patient could play checkers but ignored the pieces on the left side of the board. “And when his attention was drawn to the pieces on this side,” the doctors wrote, “he recognized them but immediately thereafter forgot them.”

This condition, called spatial neglect, challenges our intuitive notions of how we understand the world. But by mapping how people lose some of their sense of space, neuroscientists are gaining new insights into how we build that sense in the first place...

The Brain: What Happens to a Linebacker's Neurons?

Wed, 18 Aug 2010 10:20:00 -0400

A blow to the head can change the neural architecture of the brain from elastic to brittle, with devastating consequences.

The Brain: The Switches That Can Turn Mental Illness On and Off

Wed, 16 Jun 2010 12:10:00 -0400

Image: iStockphoto

This month’s column is a tale of two rats. One rat got lots of attention from its mother when it was young; she licked its fur many times a day. The other rat had a different experience. Its mother hardly licked its fur at all. The two rats grew up and turned out to be very different. The neglected rat was easily startled by noises. It was reluctant to explore new places. When it experienced stress, it churned out lots of hormones. Meanwhile, the rat that had gotten more attention from its mother was not so easily startled, was more curious, and did not suffer surges of stress hormones.

The same basic tale has repeated itself hundreds of times in a number of labs. The experiences rats had when they were young altered their behavior as adults. We all intuit that this holds true for people, too, if you replace fur-licking with school, television, family troubles, and all the other experiences that children have. But there’s a major puzzle lurking underneath this seemingly obvious fact of life. Our brains develop according to a recipe encoded in our genes. Each of our brain cells contains the same set of genes we were born with and uses those genes to build proteins and other molecules throughout its life. The sequence of DNA in those genes is pretty much fixed. For experiences to produce long-term changes in how we behave, they must be somehow able to reach into our brains and alter how those genes work.

Neuroscientists are now mapping that mechanism. Our experiences don’t actually rewrite the genes in our brains, it seems, but they can do something almost as powerful. Glued to our DNA are thousands of molecules that shut some genes off and allow other genes to be active. Our experiences can physically rearrange the pattern of those switches and, in the process, change the way our brain cells work. This research has a truly exciting implication: It may be possible to rearrange that pattern ourselves and thereby relieve people of psychiatric disorders like severe anxiety and depression. In fact, scientists are already easing those symptoms in mice.

The Brain: The First Yardstick for Measuring Smells

Mon, 17 May 2010 12:10:00 -0500

iStockphoto

Your nose is a paradox. In some ways the human sense of smell is astonishingly precise. For example, natural gas companies add a smelly molecule called n-butyl mercaptan to natural gas, which is odorless by itself, so that people can sniff gas leaks. All it takes is one n-butyl mercaptan molecule for every 10 billion molecules of methane to do the trick. To put this precision in perspective, imagine you are standing in front of two Olympic-size swimming pools. One of them contains a grand total of three drops of n-butyl mercaptan, and the other has none. Your nose could tell the difference.

But don’t get too smug, because in other ways your sense of smell is practically useless. To judge for yourself, find someone to help you run a simple experiment. Close your eyes while your partner raids your refrigerator and then holds different foods under your nose. Try to name each scent. If you’re like most people, you’ll bomb. In a number of studies, scientists have found that people tested on items in their own kitchens and garages give the wrong answer at least half the time. And as bad as we normally are at identifying smells, we can easily be fooled into doing worse. If orange food coloring is added to cherry-flavored soda, for example, people are more likely to say that it smells like oranges...

The Brain: Why Athletes Are Geniuses

Fri, 16 Apr 2010 12:10:00 -0500

The qualities that set a great athlete apart from the rest of us lie not just in the muscles and the lungs but also between the ears. That’s because athletes need to make complicated decisions in a flash. One of the most spectacular examples of the athletic brain operating at top speed came in 2001, when the Yankees were in an American League playoff game with the Oakland Athletics. Shortstop Derek Jeter managed to grab an errant throw coming in from right field and then gently tossed the ball to catcher Jorge Posada, who tagged the base runner at home plate. Jeter’s quick decision saved the game—and the series—for the Yankees. To make the play, Jeter had to master both conscious decisions, such as whether to intercept the throw, and unconscious ones. These are the kinds of unthinking thoughts he must make in every second of every game: how much weight to put on a foot, how fast to rotate his wrist as he releases a ball, and so on. In recent years neuroscientists have begun to catalog some fascinating differences between average brains and the brains of great athletes. By understanding what goes on in athletic heads, researchers hope to understand more about the workings of all brains—those of sports legends and couch potatoes alike...

The Brain: Look Deep Into the Mind's Eye

Tue, 23 Mar 2010 13:10:00 -0500

One day in 2005, a retired building surveyor in Edinburgh visited his doctor with a strange complaint: His mind’s eye had suddenly gone blind.

The surveyor, referred to as MX by his doctors, was 65 at the time. He had always felt that he possessed an exceptional talent for picturing things in his mind. The skill had come in handy in his job, allowing MX to recall the fine details of the buildings he surveyed. Just before drifting off to sleep, he enjoyed running through recent events as if he were watching a movie. He could picture his family, his friends, and even characters in the books he read.

Then these images all vanished. The change happened shortly after MX went to a hospital to have his blocked coronary arteries treated. As a cardiologist snaked a tube into the arteries and cleared out the obstructions, MX felt a “reverberation” in his head and a tingling in his left arm. He didn’t think to mention it to his doctors at the time. But four days later he realized that when he closed his eyes, all was darkness.

The Brain: The Primitive, Complicated, Essential Emotion Called Fear

Tue, 16 Feb 2010 10:40:00 -0600

Are you a man or a mouse? No matter how you answer, you experience fear the same way in your brain.

The Brain: What Is the Speed of Thought?

Wed, 16 Dec 2009 15:50:00 -0600

Faster than a bird and slower than sound. But that may be besides the point: Efficiency and timing seem to be more important anyway.

The Brain: Humanity's Other Basic Instinct: Math

Tue, 17 Nov 2009 09:35:00 -0600

New research suggests that math has evolved its way right into our neurons—and monkeys', too.

The Brain: Where Does Sex Live in the Brain? From Top to Bottom.

Thu, 10 Sep 2009 06:30:00 -0500

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Image: iStockphoto

On April 11, 1944, a doctor named T. C. Erickson addressed the Chicago Neurological Society about a patient he called Mrs. C. W. At age 43 she had started to wake up many nights feeling as if she were having sex—or as she put it to Erickson, feeling “hot all over.” As the years passed her hot spells struck more often, even in the daytime, and began to be followed by seizures that left her unable to speak. Erickson examined Mrs. C. W. when she was 54 and diagnosed her with nymphomania. He prescribed a treatment that was shockingly common at the time: He blasted her ovaries with X-rays.

Despite the X-rays, Mrs. C. W.’s seizures became worse, leaving her motionless and feeling as if an egg yolk were running down her throat. Erickson began to suspect that her sexual feelings were emanating not from her ovaries but from her head. Doctors opened up her skull and discovered a slow-growing tumor pressing against her brain. After the tumor was removed and Mrs. C. W. recovered, the seizures faded. “When asked if she still had any ‘passionate spells,’” Erickson recounted, “she said, ‘No, I haven’t had any; they were terrible things.’”

The Brain: The Dark Matter of the Human Brain

Wed, 19 Aug 2009 10:40:00 -0500

Meet the forgotten 90 percent of your brain: glial cells, which outnumber your neurons ten to one. And no one really knows what they do.

The Brain: Stop Paying Attention: Zoning Out Is a Crucial Mental State

Mon, 15 Jun 2009 12:15:00 -0500

Researchers say a wandering mind may be important to setting goals, making discoveries, and living a balanced life.