Chapter 15. Language and Our Divided Brain
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Jason G Goldman We humans don’t typically agree on all that much, but there is at least one thing that an impressive amount of us accept: which hand is easiest to control. If you use one hand for writing, you probably use the same one for eating as well, and most of us – around 85% of our species – prefer our right hands. In fact, "there has never been any report of a human population in which left-handed individuals predominate", according to archaeologist Natalie Uomini at the University of Liverpool in the UK. Lateralisation of limb use – that is, a bias towards one side or the other – usually begins in the brain. We know that some tasks are largely controlled by brain activity in the left hemisphere, while the right hemisphere governs other tasks. Confusingly, there is some crossing of nerves between the body and the brain, which means it’s actually the left side of the brain that has more control over the right side of the body and vice versa. In other words, the brain’s left hemisphere helps control the operation of the right hand, eye, leg and so on. Some argue that this division of neurological labour has been a feature of animals for half a billion years. Perhaps it evolved because it is more efficient to allow the two hemispheres to carry out different computations at the same time. The left side of the brain, for instance, might have evolved to carry out routine operations – things like foraging for food – while the right side was kept free to detect and react rapidly to unexpected challenges in the environment – an approaching predator, for instance. This can be seen in various fish, toads and birds, which are all more likely to attack prey seen in the right eye. © 2014 BBC.
|By Marissa Fessenden Songbirds stutter, babble when young, become mute if parts of their brains are damaged, learn how to sing from their elders and can even be "bilingual"—in other words, songbirds' vocalizations share a lot of traits with human speech. However, that similarity goes beyond behavior, researchers have found. Even though humans and birds are separated by millions of years of evolution, the genes that give us our ability to learn speech have much in common with those that lend birds their warble. A four-year long effort involving more than 100 researchers around the world put the power of nine supercomputers into analyzing the genomes of 48 species of birds. The results, published this week in a package of eight articles in Science and 20 papers in other journals, provides the most complete picture of the bird family tree thus far. The project has also uncovered genetic signatures in song-learning bird brains that have surprising similarities to the genetics of speech in humans, a finding that could help scientists study human speech. The analysis suggests that most modern birds arose in an impressive speciation event, a "big bang" of avian diversification, in the 10 million years immediately following the extinction of dinosaurs. This period is more recent than posited in previous genetic analyses, but it lines up with the fossil record. By delving deeper into the rich data set, research groups identified when birds lost their teeth, investigated the relatively slow evolution of crocodiles and outlined the similarities between birds' and humans' vocal learning ability, among other findings. © 2014 Scientific American,
|By Ingrid Wickelgren Confusion is one symptom of a concussion. But confusion may also characterize decisions about how soon to let an athlete play after taking a hit to the head. Sizing up symptoms such as dizziness and nausea is subjective, after all. Now a study suggests that a blood test could objectively determine whether or not the damage is bad enough to put a player on the bench. The work is in the Journal of Neurotrauma. [Robert Siman et al, Serum SNTF Increases in Concussed Professional Ice Hockey Players and Relates to the Severity of Post Concussion Symptoms] A strong blow to the head causes chemical changes within nerve cells that damage their structural proteins. Among the debris is a protein fragment called SNTF—which in more severe cases, spills into the bloodstream. The new study followed 20 professional hockey players who got concussions with symptoms that lasted six days or more. And blood levels of SNTF were much higher one hour to six days later than were levels of the protein fragment in eight other athletes who had gotten concussions that cleared up within five days. Levels were also low in 45 non-concussed players tested during the pre-season. A blood test for SNTF might thus forecast recovery time from a head injury. Combined with other neurological tests, levels of this molecule could help doctors tell athletes when it’s safe to suit up again. © 2014 Scientific American
Keyword: Brain Injury/Concussion
Link ID: 20419 - Posted: 12.16.2014
by Colin Barras It's not just great minds that think alike. Dozens of the genes involved in the vocal learning that underpins human speech are also active in some songbirds. And knowing this suggests that birds could become a standard model for investigating the genetics of speech production – and speech disorders. Complex language is a uniquely human trait, but vocal learning – the ability to pick up new sounds by imitating others – is not. Some mammals, including whales, dolphins and elephants, share our ability to learn new vocalisations. So do three groups of birds: the songbirds, parrots and hummingbirds. The similarities between vocal learning in humans and birds are not just superficial. We know, for instance, that songbirds have specialised vocal learning brain circuits that are similar to those that mediate human speech. What's more, a decade ago we learned that FOXP2, a gene known to be involved in human language, is also active in "area X" of the songbird brain – one of the brain regions involved in those specialised vocal learning circuits. Andreas Pfenning at the Massachusetts Institute of Technology and his colleagues have now built on these discoveries. They compared maps of genetic activity – transcriptomes – in brain tissue taken from the zebra finch, budgerigar and Anna's hummingbird, representing the three groups of vocal-learning birds. © Copyright Reed Business Information Ltd.
By JOHN McWHORTER “TELL me, why should we care?” he asks. It’s a question I can expect whenever I do a lecture about the looming extinction of most of the world’s 6,000 languages, a great many of which are spoken by small groups of indigenous people. For some reason the question is almost always posed by a man seated in a row somewhere near the back. Asked to elaborate, he says that if indigenous people want to give up their ancestral language to join the modern world, why should we consider it a tragedy? Languages have always died as time has passed. What’s so special about a language? The answer I’m supposed to give is that each language, in the way it applies words to things and in the way its grammar works, is a unique window on the world. In Russian there’s no word just for blue; you have to specify whether you mean dark or light blue. In Chinese, you don’t say next week and last week but the week below and the week above. If a language dies, a fascinating way of thinking dies along with it. I used to say something like that, but lately I have changed my answer. Certainly, experiments do show that a language can have a fascinating effect on how its speakers think. Russian speakers are on average 124 milliseconds faster than English speakers at identifying when dark blue shades into light blue. A French person is a tad more likely than an Anglophone to imagine a table as having a high voice if it were a cartoon character, because the word is marked as feminine in his language. This is cool stuff. But the question is whether such infinitesimal differences, perceptible only in a laboratory, qualify as worldviews — cultural standpoints or ways of thinking that we consider important. I think the answer is no. Furthermore, extrapolating cognitive implications from language differences is a delicate business. In Mandarin Chinese, for example, you can express If you had seen my sister, you’d have known she was pregnant with the same sentence you would use to express the more basic If you see my sister, you know she’s pregnant. One psychologist argued some decades ago that this meant that Chinese makes a person less sensitive to such distinctions, which, let’s face it, is discomfitingly close to saying Chinese people aren’t as quick on the uptake as the rest of us. The truth is more mundane: Hypotheticality and counterfactuality are established more by context in Chinese than in English. © 2014 The New York Times Company
Link ID: 20401 - Posted: 12.08.2014
| By Carolyn Gregoire When reading about Harry Potter's adventures fighting Lord Voldemort or flying around the Quidditch field on his broomstick, we can become so absorbed in the story that the characters and events start to feel real. And according to neuroscientists, there's a good reason for this. Researchers in the Machine Learning Department at Carnegie Mellon University scanned the brains of Harry Potter readers, and found that reading about Harry's adventures activates the same brain regions used to perceive people's intentions and actions in the real world. The researchers performed fMRI scans on a group of eight study participants while they read chapter nine of Harry Potter and the Sorcerer's Stone, which describes Harry's first flying lesson. Then, they analyzed the scans, one cubic millimeter at a time, for four-word segments of the chapter in order to build the first integrated computational model of reading. The researchers created a technique such that for each two-second fMRI scan, the readers would see four words. And for each word, the researchers identified 195 detailed features that the brain would process. Then, an algorithm was applied to analyze the activation of each millimeter of the brain for each two-second scan, associating various word features with different regions of the brain. Using the model, the researchers were able to predict which of two passages the subjects were reading with a 74 percent accuracy rate. ©2014 TheHuffingtonPost.com, Inc
By Gabe Bergado It's not news that reading has countless benefits: Poetry stimulates parts of the brain linked to memory and sparks self-reflection; kids who read the Harry Potter books tend to be better people. But what about people who only read newspapers? Or people who scan Twitter all day? Are those readers' brains different from literary junkies who peruse the pages of 19th century fictional classics? Short answer: Yes — reading enhances connectivity in the brain. But readers of fiction? They're a special breed. The study: A 2013 Emory University study looked at the brains of fiction readers. Researchers compared the brains of people after they read to the brains of people who didn't read. The brains of the readers — they read Robert Harris' Pompeii over a nine-day period at night — showed more activity in certain areas than those who didn't read. Specifically, researchers found heightened connectivity in the left temporal cortex, part of the brain typically associated with understanding language. The researchers also found increased connectivity in the central sulcus of the brain, the primary sensory region, which helps the brain visualize movement. When you visualize yourself scoring a touchdown while playing football, you can actually somewhat feel yourself in the action. A similar process happens when you envision yourself as a character in a book: You can take on the emotions they are feeling. It may sound hooey hooey, but it's true: Fiction readers make great friends as they tend to be more aware of others' emotions. Copyright © Mic Network Inc.
Some teenagers appear to show changes in their brains after one season of playing American football, a small study suggests. Even though players were not concussed during the season, researchers found abnormalities similar to the effects of mild traumatic brain injury. Twenty-four players aged between 16 and 18 were studied and devices on their helmets measured head impacts. The study was presented to the Radiological Society of North America. In recent years, a number of reports have expressed concern about the potential effects on young, developing brains of playing contact sports. These studies have tended to focus on brain changes as a result of concussion. But this study focused on the effects of head impacts on the brain, even when players did not suffer concussion at any point during the season. Using detailed scans of the players' brains before the season began and then again after it ended, the researchers were able to identify slight changes to the white matter of the brain. White matter contains millions of nerve fibres which act as communication cables between the brain's regions. Those players who were hit harder and hit more often were more likely to show these changes in post-season brain scans. Dr Alex Powers, co-author and paediatric neurosurgeon at Wake Forest Baptist Medical Centre in North Carolina, said the changes were a direct result of the hits received by the young players during their football season. BBC © 2014
By BILL PENNINGTON It happens dozens of times in every N.F.L. game. There is a fierce collision, or perhaps a running back is slammed to the ground. Most of the time, all the players rise to their feet uneventfully. Other times, as the pileup unravels, a player gets up slowly. His gait may be unsteady. For decades in the N.F.L., the operative term for the situation was that someone “got dinged.” It was a cute, almost harmless-sounding description of what was often a concussion or a worrying subconcussive blow to the head. But with the N.F.L. agreeing to pay hundreds of millions of dollars to settle a lawsuit brought by about 5,000 former players who said the league hid from them the dangers of repeated hits to the head, a backpedaling league has corrected its lingo and hastily amended its methodology. The N.F.L. now has a concussion management protocol, outlined in an inches-thick document that commands teams to institute a specific, detailed game-day and postconcussion course of action. Once, the treatment of players with head injuries varied from team to team and could be haphazard. Beginning last season, all players suspected of having a head injury — should they lose consciousness from a collision or experience symptoms like a headache, dizziness or disorientation — were required to go through the concussion protocol system. It features a broad cast: a head-injury spotter in the press box, athletic trainers on the bench, doctors and neuro-trauma specialists on the sideline and experts in neuro-cognitive testing in the locker room. The system is far from foolproof — players with serious symptoms remain in games. But as the N.F.L. grapples with a sobering threat to the welfare of its work force, not to mention a public-relations nightmare, the new concussion protocol is meant to establish a systemic, itemized policy on how potential brain injuries should be handled. © 2014 The New York Times Company
Keyword: Brain Injury/Concussion
Link ID: 20372 - Posted: 12.01.2014
By John Edward Terrell We will certainly hear it said many times between now and the 2016 elections that the country’s two main political parties have “fundamental philosophical differences.” But what exactly does that mean? At least part of the schism between Republicans and Democrats is based in differing conceptions of the role of the individual. We find these differences expressed in the frequent heated arguments about crucial issues like health care and immigration. In a broad sense, Democrats, particularly the more liberal among them, are more likely to embrace the communal nature of individual lives and to strive for policies that emphasize that understanding. Republicans, especially libertarians and Tea Party members on the ideological fringe, however, often trace their ideas about freedom and liberty back to Enlightenment thinkers of the 17th and 18th centuries, who argued that the individual is the true measure of human value, and each of us is naturally entitled to act in our own best interests free of interference by others. Self-described libertarians generally also pride themselves on their high valuation of logic and reasoning over emotion. The basic unit of human social life is not and never has been the selfish and self-serving individual. Philosophers from Aristotle to Hegel have emphasized that human beings are essentially social creatures, that the idea of an isolated individual is a misleading abstraction. So it is not just ironic but instructive that modern evolutionary research, anthropology, cognitive psychology and neuroscience have come down on the side of the philosophers who have argued that the basic unit of human social life is not and never has been the selfish, self-serving individual. Contrary to libertarian and Tea Party rhetoric, evolution has made us a powerfully social species, so much so that the essential precondition of human survival is and always has been the individual plus his or her relationships with others. © 2014 The New York Times Company
Link ID: 20371 - Posted: 12.01.2014
|By Jason G. Goldman A sharp cry pierces the air. Soon a worried mother deer approaches the source of the sound, expecting to find her fawn. But the sound is coming from a speaker system, and the call isn't that of a baby deer at all. It's an infant fur seal's. Because deer and seals do not live in the same habitats, mother deer should not know how baby seal screams sound, reasoned biologists Susan Lingle of the University of Winnipeg and Tobias Riede of Midwestern University, who were running the acoustic experiment. So why did a mother deer react with concern? Over two summers, the researchers treated herds of mule deer and white-tailed deer on a Canadian farm to modified recording of the cries of a wide variety of infant mammals—elands, marmots, bats, fur seals, sea lions, domestic cats, dogs and humans. By observing how mother deer responded, Lingle and Riede discovered that as long as the fundamental frequency was similar to that of their own infants' calls, those mothers approached the speaker as if they were looking for their offspring. Such a reaction suggests deep commonalities among the cries of most young mammals. (The mother deer did not show concern for white noise, birdcalls or coyote barks.) Lingle and Riede published their findings in October in the American Naturalist. Researchers had previously proposed that sounds made by different animals during similar experiences—when they were in pain, for example—would share acoustic traits. “As humans, we often ‘feel’ for the cry of young animals,” Lingle says. That empathy may arise because emotions are expressed in vocally similar ways among mammals. © 2014 Scientific American
by Aviva Rutkin THERE is only one real rule to conversing with a baby: talking is better than not talking. But that one rule can make a lifetime of difference. That's the message that the US state of Georgia hopes to send with Talk With Me Baby, a public health programme devoted to the art of baby talk. Starting in January, nurses will be trained in the best way to speak to babies to help them learn language, based on what the latest neuroscience says. Then they, along with teachers and nutritionists, will model this good behaviour for the parents they meet. Georgia hopes to expose every child born in 2015 in the Atlanta area to this speaking style; by 2018, the hope is to reach all 130,000 or so newborns across the state. Talk With Me Baby is the latest and largest attempt to provide "language nutrition" to infants in the US – a rich quantity and variety of words supplied at a critical time in the brain's development. Similar initiatives have popped up in Providence, Rhode Island, where children have been wearing high-tech vests that track every word they hear, and Hollywood, where the Clinton Foundation has encouraged television shows like Parenthood and Orange is the New Black to feature scenes demonstrating good baby talk. "The idea is that language is as important to the brain as food is to physical growth," says Arianne Weldon, director of Get Georgia Reading, one of several partner organisations involved in Talk With Me Baby. © Copyright Reed Business Information Ltd.
By Virginia Morell When we listen to someone talking, we hear some sounds that combine to make words and other sounds that convey such things as the speaker’s emotions and gender. The left hemisphere of our brain manages the first task, while the right hemisphere specializes in the second. Dogs also have this kind of hemispheric bias when listening to the sounds of other dogs. But do they have it with human sounds? To find out, two scientists had dogs sit facing two speakers. The researchers then played a recorded short sentence—“Come on, then”—and watched which way the dogs turned. When the animals heard recordings in which individual words were strongly emphasized, they turned to the right—indicating that their left hemispheres were engaged. But when they listened to recordings that had exaggerated intonations, they turned to the left—a sign that the right hemisphere was responding. Thus, dogs seem to process the elements of speech very similarly to the way humans do, the scientists report online today in Current Biology. According to the researchers, the findings support the idea that our canine pals are indeed paying close attention not only to who we are and how we say things, but also to what we say. © 2014 American Association for the Advancement of Science.
By Amy Ellis Nutt Debbie Hall undergoes external brain stimulation at Ohio State's Wexner Medical Center. Hall was partially paralyzed on her left side after a stroke. Doctors are conducting a study to see if a device known as NexStim can `prep` a stroke victim's brain immediately prior to physical therapy so that the therapy will be more effective. (The Ohio State University Wexner Medical Center) Using non-invasive transcranial magnetic stimulation, or TMS, researchers at Ohio State Wexner Medical Center may have found a way to help prep a stroke victim's brain prior to physical therapy to aid a more complete recovery. When one side of the brain is damaged by a stroke, the corresponding healthy part goes into overdrive in order to compensate, said Dr. Marcie Bockbrader, principle investigator of the study. She believes the hyperactivity in the healthy side may actually slow recovery in the injured side. The technology, called NexStim, employs TMS to prepare a stroke patient's brain for physical therapy by sending low-frequency magnetic pulses painlessly through a victim's scalp to suppress activity in the healthy part of the motor cortex. This allows the injured side to make use of more energy during physical therapy, which immediately follows the transcranial magnetic stimulation. "This device targets the overactive side, quieting it down enough, so that through therapies the injured side can learn to express itself again," said Bockbrader, an assistant professor of physical medicine and rehabilitation, in a new release.
Link ID: 20349 - Posted: 11.24.2014
By Bethany Brookshire WASHINGTON — Estrogen can protect the brain from harmful inflammation following traumatic injury, a new study in zebra finches suggests. Boosting levels of the sex hormone in the brain might help prevent the cell loss that occurs following damage from injuries such as stroke. Estrogen levels quadrupled around the damaged area in both male and female zebra finches after researchers gave them experimental brain injuries, Colin Saldanha and colleagues at American University in Washington, D.C., reported November 17 at the annual meeting of the Society for Neuroscience. When the scientists prevented finch brains from making estrogen, inflammatory proteins at damaged sites increased. The helpful estrogen didn’t come from gonads. It’s made within the brain by support cells called astrocytes close to the injury. Injury inflames the brain. Initially, this inflammation recruits helpful cells to the damaged area and aids in recovery. But the long-term presence of inflammatory proteins can cause harm, killing off brain cells and reducing functions such as movement and memory. The researchers hope that by understanding how estrogen reduces inflammatory proteins, therapies might boost this natural estrogen production to keep harmful inflammation at bay. © Society for Science & the Public 2000 - 2014.
Mo Costandi A team of neuroscientists in America say they have rediscovered an important neural pathway that was first described in the late nineteenth century but then mysteriously disappeared from the scientific literature until very recently. In a study published today in Proceedings of the National Academy of Sciences, they confirm that the prominent white matter tract is present in the human brain, and argue that it plays an important and unique role in the processing of visual information. The vertical occipital fasciculus (VOF) is a large flat bundle of nerve fibres that forms long-range connections between sub-regions of the visual system at the back of the brain. It was originally discovered by the German neurologist Carl Wernicke, who had by then published his classic studies of stroke patients with language deficits, and was studying neuroanatomy in Theodor Maynert’s laboratory at the University of Vienna. Wernicke saw the VOF in slices of monkey brain, and included it in his 1881 brain atlas, naming it the senkrechte occipitalbündel, or ‘vertical occipital bundle’. Maynert - himself a pioneering neuroanatomist and psychiatrist, whose other students included Sigmund Freud and Sergei Korsakov - refused to accept Wernicke’s discovery, however. He had already described the brain’s white matter tracts, and had arrived at the general principle that they are oriented horizontally, running mostly from front to back within each hemisphere. But the pathway Wernicke had described ran vertically. Another of Maynert’s students, Heinrich Obersteiner, identified the VOF in the human brain, and mentioned it in his 1888 textbook, calling it the senkrechte occipitalbündel in one illustration, and the fasciculus occipitalis perpendicularis in another. So, too, did Heinrich Sachs, a student of Wernicke’s, who labeled it the stratum profundum convexitatis in his 1892 white matter atlas. © 2014 Guardian News and Media Limited
Link ID: 20333 - Posted: 11.20.2014
By David Shultz WASHINGTON, D.C.—Reciting the days of the week is a trivial task for most of us, but then, most of us don’t have cooling probes in our brains. Scientists have discovered that by applying a small electrical cooling device to the brain during surgery they could slow down and distort speech patterns in patients. When the probe was activated in some regions of the brain associated with language and talking—like the premotor cortex—the patients’ speech became garbled and distorted, the team reported here yesterday at the Society for Neuroscience’s annual meeting. As scientists moved the probe to other speech regions, such as the pars opercularis, the distortion lessened, but speech patterns slowed. (These zones and their effects are displayed graphically above.) “What emerged was this orderly map,” says team leader Michael Long, a neuroscientist at the New York University School of Medicine in New York City. The results suggest that one region of the brain organizes the rhythm and flow of language while another is responsible for the actual articulation of the words. The team was even able to map which word sounds were most likely to be elongated when the cooling probe was applied. “People preferentially stretched out their vowels,” Long says. “Instead of Tttuesssday, you get Tuuuesdaaay.” The technique is similar to the electrical probe stimulation that researchers have been using to identify the function of various brain regions, but the shocks often trigger epileptic seizures in sensitive patients. Long contends that the cooling probe is completely safe, and that in the future it may help neurosurgeons decide where to cut and where not to cut during surgery. © 2014 American Association for the Advancement of Science.
By Laura Geggel A major pathway of the human brain involved in visual perception, attention and movement — and overlooked by many researchers for more than a century — is finally getting its moment in the sun. In 2012, researchers made note of a pathway in a region of the brain associated with reading, but "we couldn't find it in any atlas," said Jason Yeatman, a research scientist at the University of Washington's Institute for Learning and Brain Sciences. "We'd thought we had discovered a new pathway that no one else had noticed before." A quick investigation showed that the pathway, known as the vertical occipital fasciculus (VOF), was not actually unknown. Famed neuroscientist Carl Wernicke discovered the pathway in 1881, during the dissection of a monkey brain that was most likely a macaque. [10 Things You Didn't Know About the Brain] But besides Wernicke's discovery, and a few other mentions throughout the years, the VOF is largely absent from studies of the human brain. This made Yeatman and his colleagues wonder, "How did a whole piece of brain anatomy get forgotten?" he said. The researchers immersed themselves in century-old brain atlases and studies, trying to decipher when and why the VOF went missing from mainstream scientific literature. They also scanned the brains of 37 individuals, and found an algorithm that can help present-day researchers pinpoint the elusive pathway.
By Kate Baggaley WASHINGTON, D.C. — Adding magnets to football helmets could reduce the risk of concussions, new research suggests. When two players collide, the magnets in their helmets would repel each other, reducing the force of the collision. “All helmet design companies and manufacturers have the same approach, which is to try to disperse the impact energy after the impact’s already occurred,” neuroscientist Raymond Colello said November 15 at the annual meeting of the Society for Neuroscience. The magnets, he says, would put a brake on the impact before it happens. The idea hasn’t been tested yet in helmets with real players, said Judy Cameron, a neuroscientist at the University of Pittsburgh. “But a lot of thought has gone into it, and the data that was shown about the ability of the magnets to actually repel each other looked extremely promising.” On the field, football players can run at nearly 20 miles per hour and can experience up to 150 g’s of force upon impact. Concussions readily occur at impacts greater than 100 g’s. Every year there are 100,000 concussions at all levels of play among the nearly 1.2 million people who play football in the United States. Colello, of Virginia Commonwealth University in Richmond, is testing magnets made in China from the rare-earth element neodymium. They are the most powerful commercially available magnets and weigh about one-third of a pound each (football helmets weigh from 3.5 to 5.5 pounds). When placed one-fourth of an inch away from each other, two magnets with their same poles face-to-face exert nearly 100 pounds of repulsive force. © Society for Science & the Public 2000 - 2014
Keyword: Brain Injury/Concussion
Link ID: 20317 - Posted: 11.17.2014
by Helen Thomson As you read this, your neurons are firing – that brain activity can now be decoded to reveal the silent words in your head TALKING to yourself used to be a strictly private pastime. That's no longer the case – researchers have eavesdropped on our internal monologue for the first time. The achievement is a step towards helping people who cannot physically speak communicate with the outside world. "If you're reading text in a newspaper or a book, you hear a voice in your own head," says Brian Pasley at the University of California, Berkeley. "We're trying to decode the brain activity related to that voice to create a medical prosthesis that can allow someone who is paralysed or locked in to speak." When you hear someone speak, sound waves activate sensory neurons in your inner ear. These neurons pass information to areas of the brain where different aspects of the sound are extracted and interpreted as words. In a previous study, Pasley and his colleagues recorded brain activity in people who already had electrodes implanted in their brain to treat epilepsy, while they listened to speech. The team found that certain neurons in the brain's temporal lobe were only active in response to certain aspects of sound, such as a specific frequency. One set of neurons might only react to sound waves that had a frequency of 1000 hertz, for example, while another set only cares about those at 2000 hertz. Armed with this knowledge, the team built an algorithm that could decode the words heard based on neural activity aloneMovie Camera (PLoS Biology, doi.org/fzv269). © Copyright Reed Business Information Ltd.