• 'Hobbit' had bigger brain than thought

    © National Museum of Nature and Science, Tokyo

    The hobbit, Homo floresiensis, lived on the island of Flores some 18,000 years ago, and now researchers have more evidence (its relatively large brain) the diminutive creature was a unique human species.

    By Charles Choi, LiveScience

    The brain of the extinct "hobbit" was bigger than often thought, researchers say.

    These findings add to evidence that the hobbit was a unique species of humans after all, not a deformed modern human, scientists added.

    The 18,000-year-old fossils of the extinct type of human officially known as Homo floresiensis were first discovered on the remote Indonesian island of Flores in 2003. Its squat, 3-foot-tall build led to the hobbit nickname. [Image Gallery: A Real-Life Hobbit]

    Scientists had suggested the hobbit was a unique branch of the human lineage Homo. It may have descended from Homo erectus, the earliest undisputed ancestor of modern humans, or an even more primitive extinct species of human, Homo habilis, which had a more apelike skeleton. However, other researchers have argued it was unlikely another species of human lasted so close to the present day, and that the hobbit was really a modern human with microcephaly, a condition that leads to an abnormally small head, a small body and some mental retardation.

    Big brains?
    One method that may help solve the mystery of the hobbit's status involves comparing the size of its brain with the size of its body. Scientists could then make similar comparisons with modern and extinct human groups and note the hobbit's differences from the groups. However, the actual size of the hobbit's brain was unclear — past estimates for its size ranged from 380 to 430 cubic centimeters (23 to 26 cubic inches), inviting confusing answers when it came to analyzing the hobbit.

    To help resolve this question, researchers scanned the interior of the only known hobbit skull with a high-resolution CT scan for the first time. They found the hobbit's brain was larger than previously suggested — 426 cubic cm (nearly 26 cubic inches), instead of the commonly cited figure of 400 cubic cm. (The modern human brain is 1,300 cubic centimeters, or 79 cubic inches, large on average.)

    Armed with this knowledge, the scientists then compared the hobbit with other groups of humans. Past studies had argued the hobbit could not have evolved from Homo erectus, which typically had a brain about 1,000 cubic centimeters (61 cubic inches) in size, because it would have suggested Homo erectus shrunk an unreasonable degree over time. However, it turned out Javanese specimens of Homo erectus had brains about 860 cubic cm (52 cubic inches) large, and combined with the newfound increased size of the hobbit's brain, the researchers say it now seems possible that Homo erectus may be the ancestor of Homo floresiensis.

    "This study does not prove who was the actual ancestral species for Homo floresiensis, but it has removed the most important concern for the model, which supposes Homo erectus was the ancestral species," researcher Yousuke Kaifu, a paleoanthropologist at Japan's National Museum of Nature and Science in Tokyo, told LiveScience.

    Hobbit ancestor alternative
    Another possibility is that the hobbit evolved from Homo habilis, whose brains were only about 600 cubic cm (37 cubic inches).

    "Homo habilis could also be the ancestor, but this model still has the problem that no fossil record exists for the presence of such a primitive form of hominin in Asia," Kaifu said. Hominins include modern and extinct human species and their direct ancestors.

    While the human lineage is ordinarily typified by increases in brain and body size, Homo floresiensis suggests this trend may go the opposite direction in special circumstances, such as when on islands. Many animals experience dwarfism on islands, including mammoths and dinosaurs.

    Future research will hopefully uncover more ancient human fossils on the island of Flores.

    "New discovery of older hominin remains from Flores would provide us with fresh materials to solve the evolutionary questions of Homo floresiensis," Kaifu said.

    Kaifu and his colleagues Daisuke Kubo and Reiko Kono detailed their findings online April 17 in the journal Proceedings of the Royal Society B.

    Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.com.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Paralyzed monkey controls arm via brain

    M.D. Madhusudan

    A paralyzed macaque monkey (like those shown) controlled its arm using an artificial neural bridge from its brain.

    By Tanya Lewis, LiveScience

    A monkey partially paralyzed by a spinal cord injury was able to control its arm using an external link between its brain and spinal cord, a new study shows.

    Even after a spinal cord injury or stroke, the nervous system wiring above and below the injury can remain intact. With that in mind, researchers created an artificial electrical connection between the injured monkey's brain and an area below the damaged part of its spinal cord. This allowed the animal to send neural signals to its spinal cord to engage its arm muscles. The findings were detailed online April 11 in the journal Frontiers in Neural Circuits.

    "In the distant future, it's conceivable that one could get lots of signals in the brain's cortex to trigger lots of stimulation in different spinal sites, and begin to restore some basic functions like grasp and movement," study co-author Eberhard Fetz, a neuroscientist at the University of Washington in Seattle, told LiveScience. But Fetz added that the technology was still a long way off. [Inside the Brain: A Photo Journey Through Time]

    Previous studies have shown that monkeys can use brain signals to control electrical stimulation of muscles that have been temporarily paralyzed, but stimulating the muscles directly caused them to fatigue very quickly. In the new study, the researchers stimulated the spine instead of the muscles, in the hope of restoring more coordinated, natural movement to a macaque monkey with an upper spinal cord lesion. That lesion partially paralyzed one of its upper arms and made the monkey unable to move its fingers independently.

    Researchers surgically implanted electrodes in the motor cortex and premotor cortex of the monkey's brain, in areas that control arm and hand movements. They also implanted electrodes in the monkey's spinal cord.

    Fetz et al / Frontiers in Neural Circuits

    In a monkey with a spinal cord injury, an artificial connection filters brain signals that activate a stimulator, which sends pulses to the spinal cord to control the animal's arm.

    The macaque was trained to move a cursor on a computer screen by flexing its wrist muscles. Later, the animal was trained to move the cursor with its mind alone, via signals recorded from the electrodes in its brain. In contrast to some previous studies that recorded single neurons, this study recorded the combined activity of groups of neurons.

    Flexing its wrist
    By using the signals recorded from the brain to control electrical stimulation of the spinal cord, the researchers created an artificial bridge between the two areas. The monkey was able to use this bridge to successfully flex its wrist muscles to drive the computer cursor.

    Next, the researchers took the weak electrical signals from muscles in the monkey's partially paralyzed arm and fed them back into the spinal cord, creating a self-reinforcing loop.

    Though these findings were only in one monkey, they suggest that artificial connections between the brain and spinal cord could restore control of the limbs following damage to the spinal cord, Fetz said. It depends on the kind of injury and the amount of control this method can achieve, he said, but it's a proof-of-concept that a brain-spinal cord connection like this could work.

    "It's a small step, but certainly a step in the right direction," said neuroscientist Lee Miller of Northwestern University, who wasn't involved in the study. The movements being demonstrated are very simple ones, Miller said, but "ultimately, spinal cord stimulation may offer promise."

    Follow Tanya Lewis on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on LiveScience.com.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Sense of place found in rat's brain

    Geir Mogen, NTNU

    By using tiny biological light switches, scientists have identified the network of cells that fire as rats navigate a maze for treats.

    By Tia Ghose, LiveScience

    Scientists have watched a specific network of brain cells light up in rats to create a mental map of their location.

    The new study, in which researchers looked at brain cells that literally turned on and off like light switches as rats navigated a maze, could shed light on how the brain creates a sense of place.

    The study is published Thursday in the journal Science.

    Finding our place
    Scientists have known the hippocampus is involved in creating mental maps, but less certain is exactly how mental maps form or why we get lost. Past studies showed that specific place cells in the hippocampus fired when animals explored a new space, but knowing which brain cells sent information to the place cells proved trickier.

    That's because tracing how any number of unknown brain cells, or neurons, are hooked up can be incredibly complicated — even in relatively simple animals such as rats.

    "A rat's brain is the size of a grape. Inside there are about 50 million neurons that are connected together at a staggering 450 billion places," said study co-author Edvard Moser, director of the Kavli Institute, in a statement.

    Mental maps
    To watch the entire process of learning a new place unfold, Moser and his colleagues created a virus that could insert tiny biological light switches into the neurons of rats. Next, they threaded optical fiber into the rats' brains to connect to the light-switch-enhanced brain cells, allowing the researchers to turn the lights on and activate the neurons at will. Finally, they inserted electrodes that could record electrical signals traveling between different brain cells.

    The team flipped those biological light switches on and off about 10,000 times as rats navigated a maze seeking tasty treats, which enabled the scientists to identify individual neurons. Simultaneously, they measured the electrical signals traveling between these brain cells.

    By combining the two pieces of information, the team was able to recreate the neural network that fires as the animals learned their location. It turned out that many different cell types were involved in creating a sense of place.

    The findings raise questions about cells that have not previously been tied to orientation.

    "One mystery is the role that the cells that are not part of the sense of direction play. They send signals to place cells, but what do they actually do?" Moser said in a statement.

    Follow Tia Ghose on Twitter @tiaghose. Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.com.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • How your brain finds your car keys

    Wei Deng / Salk Institute for Biological Studies

    Different neurons in the dentate gyrus fire when mice encounter new places (green neurons) versus familiar spaces (red neurons).

    By Tia Ghose
    LiveScience

    The saying that it's impossible to step into the same river twice may be true, at least as far as the brain is concerned.

    Different neurons in a brain region called the dentate gyrus fire when encountering a place for the first or second time. Different brain cells also fire to distinguish subtle changes in familiar terrain, new research in mice suggests.

    The findings, which were published March 20 in the journal eLife, may help unravel how the brain tracks minute changes in our everyday environments, a process known as pattern separation. The phenomenon is how we find our car keys or wallet, for instance.

    "Everyday, we have to remember subtle differences between how things are today versus how they were yesterday, from where we parked our car to where we left our cellphone," said study co-author Fred H. Gage, a neuroscientist at the Salk Institute, in a statement. "We found how the brain makes these distinctions, by storing separate 'recordings' of each environment in the dentate gyrus." [10 Odd Facts About the Brain]

    Small differences
    Several studies suggested that a brain region called the hippocampus helps people navigate and orient themselves in space, in part by retrieving memories from different environments. For instance, London cabbies have more hippocampal gray matter after training in navigation.  

    But exactly how the hippocampus sifted memories of new and familiar places wasn't fully understood.

    Previous studies found that a sub-region of the hippocampus, called the dentate gyrus, helped the brain pick out important patterns from detail-rich memories of the environment — such as where someone placed their keys from one day to the next. The same region may play a role in the eerie feeling of déjà vu.

    Different brain cells
    To find out, Gage and his colleagues measured firing from neurons, or brain cells, in mice as they navigated a new chamber.

    They then recorded their brain activity while the same mice explored either the exact same chamber or a very similar one.

    The team found that neurons in a sub-region of the hippocampus called CA-1 fired when mice were in both new and familiar environments. But in the dentate gyrus, different groups of neurons fired in undiscovered territory versus familiar spaces. Different collections of cells also fired in the dentate gyrus in the two similar chambers.

    The findings suggest the neurons that encode our memories of a new place are different from those that fire when we revisit it and notice its subtle transformations. 

    Follow Tia Ghose on Twitter @tiaghose. Follow LiveScience @livescience, Facebook and Google+. Original article on LiveScience.com.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Brain comparison suggests that Neanderthals lacked social skills

    Frank Franklin II / AP file

    A reconstructed Neanderthal skeleton, right, is on display near a modern human's skeleton, left, at the American Museum of Natural History in New York.

    By Jennifer Viegas
    Discovery News

    For ages, anthropologists have puzzled over Neanderthal and human brains, since they were the same size. If each species had comparable brain power, why did humans dominate?

    A comparison of Neanderthal and human brains has revealed it was a matter of allocation: Neanderthal brains focused more on vision and movement, leaving less room for cognition related to social networking.

    According to the study, published in the Proceedings of the Royal Society B, bigger-eyed and larger-bodied Neanderthals required more brain space devoted to the visual system and basic body functions, leaving less area for what co-author Robin Dunbar called "the smart part."

    He explained to Discovery News that this is "the part that is doing the creative thinking."

    Eye sockets measured
    Dunbar, a professor of evolutionary psychology at the University of Oxford, and colleagues Eiluned Pearce and Chris Stringer compared the skulls of 32 anatomically modern humans and 13 Neanderthals. The skulls date to 27,000 to 75,000 years ago. The researchers noticed that Neanderthals had significantly larger eye sockets.

    The researchers next used the known relationship between the height of the eye socket and the size of visual brain areas in living primates to estimate how much of each brain was dedicated to visual processing. Once differences in body and visual system size were taken into account, the researchers could then compare how much of the brain was left over for other types of cognition.

    It's clear that environmental differences affected the evolution of each species. The common ancestor of Neanderthals and Homo sapiens was Homo heidelbergensis. It had a bulkier body, as did the Neanderthals, but Homo heidelbergensis did not possess enlarged eyes.

    "The large eyes (of Neanderthals) are purely an adaptation to low light levels, and long dark nights at higher latitudes outside the tropics," Dunbar said.

    Flash interactive: Before and after humans

    Neanderthals also tended to be shorter than humans, which again was an adaptation to colder climates. Shorter stature reduces heat loss through the extremities. Modern Eskimos exhibit some of this adaptation.

    Neanderthals in Europe also "developed a very confrontational and dangerous style of hunting, and were very dependent on a heavy meat diet," Dunbar shared. "Modern humans (in Africa) developed the bow and arrow, as well as spear throwers, which allowed hunting at arms’ length and often focused on smaller prey."

    As for what happened to the Neanderthals, some researchers believe that they were simply absorbed into the modern human population. There is evidence that, as numerous humans migrated north into Europe, they interbred with Neanderthals.

    Social smarts
    Another theory, supported by this new study, is that Neanderthals went extinct because they were less capable of forming larger social networks. Pearce theorized that "smaller social groups might have made Neanderthals less able to cope with the difficulties of their harsh Eurasian environments because they would have had fewer friends to help them out in times of need."

    She continued, "Overall, differences in brain organization and social cognition may go a long way towards explaining why Neanderthals went extinct whereas modern humans survived."

    Dunbar further thinks that new diseases brought in by humans could have hurt Neanderthals. He said, "It was clear that, by the end, they were struggling to maintain a foothold in Ice Age Europe, having been squeezed down into the southern appendages of Europe (in places like Spain and Italy)."

    Clive Gamble, an expert on the archaeology of human origins and a professor at Southampton University, praised the new work. "This paper cracks a big problem in human evolution. Neanderthals had brains as big as ours, yet did not regularly produce the sorts of cultural stuff — art, ornamentation and complicated tools — that we take for granted ... Brains got bigger, but in different ways," Gamble said.

    "I've long argued for social differences between Neanderthals and ourselves," Gamble concluded. "It doesn't make us better than them and it doesn’t confirm the age-old prejudices about stupid, brutish Neanderthals. What it does do, quite literally, is make us see them with different eyes."

    More from Discovery News:

    Copyright 2013 Discovery Channel

  • Say what? Mystery of 'cocktail party' hearing solved

    Credit: Neuron, Zion-Golumbic et al

    At a cocktail party, the brain pays attention to a single speaker, while ignoring others.

    By Tanya Lewis
    LiveScience

    The mystery of how the brain hones in on a single speaker in a noisy room may be solved, a new study shows.

    Studying the infamous "cocktail party problem," researchers found that brain waves are shaped to allow the brain to track the sounds it's interested in while ignoring competing sounds. The findings could be used to aid people with problems hearing or focusing on sounds, linked to  attention deficit hyperactivity disorder (ADHD), autism and aging, researchers reported Wednesday in the journal Neuron.

    Humans don't have a way of closing their minds to sounds, and so the brain "hears" everything that reaches a person's ears. The new study confirmed this.

    "We also provide the first clear evidence that there may be brain locations in which there is exclusive representation of an attended speech segment, with ignored conversations apparently filtered out," senior author Charles Schroeder, a neuroscientist at Columbia University, said in a statement.

    In the study, the researchers recorded the brain activity of epilepsy patients, who had recently undergone surgery, as they listened to natural spoken sentences. In order to figure out how the brain ignored or focused on various sounds, the researchers showed the patients two side-by-side videos of people talking, and told them to pay attention to one of the speakers.

    In the brain's auditory cortex, which processes incoming sound signals, the brain activity represented both the speech being attended to and that being ignored, but the attended speech had stronger signals. [10 Odd Facts About the Brain]

    In higher-level processing regions responsible for things like language and attention control, only the attended speech had a detectable, clear representation, the results showed. That representation became more refined as a sentence progressed, suggesting as a cocktail-party conversation continues, the brain focuses more and more only on those sentences while tuning out others.

    Previous studies of the cocktail party problem have used simplified, unnatural sounds such as beeps or brief phrases, Schroeder said, whereas this study used natural speech.

    The ability to study widespread patterns of brain activity in surgical epilepsy patients provides a link between work on a "brain activity map" in animals and uniquely human abilities like language and music, the researchers say.

    Follow Tanya Lewis @tanyalewis314. Follow us @livescience, Facebook or Google+. This article was first published on LiveScience.com.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Two rats, thousands of miles apart, cooperate telepathically via brain implant

    Nicolelis lab / Duke University

    If you're a lab rat, life is full of choices.

    By Nidhi Subbaraman

    Two rats — one in North Carolina, the other in Brazil — worked together on a task by communicating telepathically, thanks to implants in their brain.

    Electrical signals from a "leader" rat’s brain were collected, encoded and then zapped into the "follower" rat’s cortex in the form of an electrical signal. The follower rat then pressed one of two levers based on a light visible only to the leader rat. The Duke University experiment is the first time two animals have collaborated through such an artificial link, and shows that the mammal brain can be trained to act on electrical signals from another animal. 

    Miguel Nicolelis, the Duke neuroscientist who led the team from Duke and the International Institute for Neuroscience of Natal in Brazil, believes that information transfer could extend to other senses, too. “You could think about taste, vision — I don’t see any problem doing this,” he told NBC News.

    He says his wired rat duo show that the linking of mammalian brains is possible, but why stop at just two? "I could see a swarm of rats be informed by one rat," he says, "Most of them driving to the source based on information from another individual," a concept he calls a "Brain Net."

    Nicolelis and crew published their findings in Scientific Reports Thursday. 

    “I still think it's wild that he made it possible,” Ron Frostig, a neurobiologist at the University of Irvine who was not involved with the experiments told NBC News. 

    This experiment is in many ways extension of brain-machine tech that has been on slow boil at the Nicolelis lab for over a decade. Earlier in February, the Nicolelis lab showed that rats could be trained to act on infrared cues. Rats, like people, can’t naturally sense infrared light — an infrared sensor activated a implant in the rats' brains. Eventually they learned to follow that signal, approached the right hole, and received a reward.

    In the latest "mind-reading" experiment, both lead and follow rats went through a series of training phases. The leader rat was trained to use a lit light bulb to choose which of two levers to press. The second rat was trained to receive and act on gentle zaps of electrical stimulation in its brain. Once the two were wired up together, the second rat received signals from the leader rat's brain indicating which lever to choose. When the follower pressed the right lever, it was rewarded with water, and the leader was rewarded as well.

    The leader rat eventually figured out that the clearer he was with his “instructions,” the better his chances of getting a double reward. Frostig pointed out that this training was crucial to the success of this series of demonstrations. 

    While the link between the rats seems telepathic to casual observer, the rats don't necessarily know the other exists, Nicolelis explains. The follower rat feels a tingle in its brain and discovers that interpreting it one way rather than another leads to a reward. Marshall Shuler — a neuroscientist at Johns Hopkins University who was Nicolelis’ student in the late 1990s — describes it as a "special and powerful case of conditioning." "What's unique about this is that one animal is getting information that has nothing to do with it environment," he told NBC News.  

    How about human telepathy?
    The researchers are years away from testing this kind of electronic telepathy in people. Still, based on what is known about how people respond to brain stimulation and implants, Shuler says we might be better than the rats at interpreting intracranial cues.

    "I would think that humans would be able to exploit this information even more efficiently," Shuler says. 

    Nicolelis says they are “perfecting the experiment” in monkeys, training them to collaborate in a virtual game. In the past, the Nicolelis lab has trained brain-implanted monkeys to control a cursor on a screen using only their thoughts. In another computer game, a monkey pawed at virtual discs of different simulated textures, and was trained to pick one texture over the other, demonstrating one way information about touch could be fed back into the brain.

    Shuler says that this line of research isn't just about person-to-person telepathy, but may very well help computers talk back to human brains. “We’re quite comfortable with patterns arising from our own sensory mechanisms,” he explained, “What’s less intuitive to us is that, as experimentalists and engineers impose artificial patterns, the brain is able to render that information useful.”

    Take the field of prosthetics, a zone the Nicolelis lab is at home in. Ultimately, Shuler says, the goal is to get prosthetics to send touch data back to the user. A number of labs have shown that the brain or residual nerves can move a prosthetic limb. What many of those smart body parts lack is a way of relaying sophisticated feedback back to the brain. The Nicolelis lab may well provide the answer. 

    Related posts: 

  • How neuroscientists are hacking into brain waves to open new frontiers

    This video provides an introduction to the infrared-sensing rat experiment. Check the Web page at http://www.nicolelislab.net/?p=345 for the full series of videos, as well as background about the experiment,

    By Alan Boyle, Science Editor, NBC News


    BOSTON — Neuroscientists are following through on the promise of artificially enhanced bodies by creating the ability to "feel" flashes of light in invisible wavelengths, or building an entire virtual body that can be controlled via brain waves.

    "Things that we used to think were hoaxes or science fiction are fast becoming reality," said Todd Coleman, a bioengineering professor at the University of California at San Diego. Coleman and other researchers surveyed the rapidly developing field of neuroprosthetics in Boston this weekend at the annual meeting of the American Association for the Advancement of Science.

    One advance came to light just in the past week, when researchers reported that they successfully wired up rats to sense infrared light and move toward the signals to get a reward. "This was the first attempt … not to restore a function but to augment the range of sensory experience," said Duke University neurobiologist Miguel Nicolelis, the research team's leader.

    The project, detailed in the journal Nature Communications, involved training rats to recognize a visible light source and poke at the source with its nose to get a sip of water. Then electrodes were implanted in a region of the rats' brains that is associated with whisker-touching. The electrodes were connected to an infrared sensor on the rats' heads, which stimulated the target neurons when the rat was facing the source of an infrared beam. Then the visible lights in the test cage were replaced by infrared lights.

    It typically took about four weeks of practice for the rats to figure out how to use their new infrared sensory system, but eventually the rats could respond to the invisible light as well as they responded to the visible light. Presumably, they could "feel" where the infrared flash was coming from, as part of their whisker-touching sense.

    Nicolelis said the experiment showed that the brain is "much more plastic than we thought" when it comes to adapting to new stimuli.

    That plasticity is the key to another set of experiments he and his colleagues have been conducting with rhesus monkeys, in which the monkeys learn to use their brain waves to control robotic arms or manipulate virtual objects on a computer screen. Over the years, Nicolelis' research team has developed a brain-cap system for monkeys that can pick up neural signals in almost 2,000 channels simultaneously, and send them wirelessly to a computer for processing. Nicolelis indicated that he was closing in on the goal of creating a system that could control a full-body exoskeleton.

    "We can get animals to control the whole body now, when you get to the 1,000-neuron margin," he said.

    Such work feeds into the Walk Again Project, a multinational effort to develop next-generation, full-body prosthetics for people with disabilities. Nicolelis wants to have an experimental brain-controlled exoskeleton ready in time to make its debut at next year's World Cup soccer finals, which are to be hosted by Brazil, Nicolelis' native country.

    "We hope we will open the World Cup with a paraplegic young adult walking onto the field," he said.

    Coleman, meanwhile, is working on ways to make brain-control devices less obtrusive. He is among several researchers who have been developing stamp-sized wireless sensors that can be worn like temporary tattoos. Such sensors can be used to monitor a person's medical signs — but if they're worn on the head, it's possible to pick up brain waves. In fact, Coleman found that the wireless tattoo sensors worked as well as the conventional, wired stick-on electrodes.

    Todd Coleman, a bioengineering professor at the University of California at San Diego, demonstrates how his "wireless tattoos" make monitoring bodily functions much easier.

    The results suggest that someday, it might be possible to develop a computer program to read the brain-wave patterns sent in by a tattoo on your forehead, and then fine-tune a virtual character to respond as if it was reading your thoughts.

    The tattoos could have more down-to-earth applications in the medical field: In the future, such sensors could be used to monitor a newborn's brain for any signs of abnormality, or an older person's brain for signs of cognitive impairment.

    "As we age, our ability to respond, or to modulate our attention to different new types of inputs, will start to slow down," Coleman said in a video interview distributed by AAAS. "Imagine if we could ... mount a sticker to the forehead that can provide quantitative outputs — measurements of that."

    Does all this sound like a dream come true for the disabled, or a nightmare for folks worried about mind-reading robots? Feel free to weigh in with your thoughts in the comment section below.

    More about the brain:

    Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

  • Big brains vs. strong immunity: Genes hint at evolutionary tug of war

    Mandel Ngan / AFP - Getty Images file

    A skull from an ancient specimen of Homo sapiens (foreground, right) is compared with a Neanderthal's skull at the Smithsonian's National Museum of Natural History in Washington. Researchers suggest that a gene linked to the immune system played a roundabout role in brain evolution.

    By Alan Boyle, Science Editor, NBC News


    Scientists say our genes contain the hints of an evolutionary tug of war that took place in the wombs of our ancestors, balancing the drive to bigger brains with the need for a strong immune system.

    The push and pull of these genetic variants apparently became more pronounced after pre-humans branched off from the ancestors of chimpanzees, according to biologists Peter Parham of Stanford University and Ashley Moffett of the University of Cambridge.

    Two years ago, Parham and other researchers suggested that interbreeding with now-extinct cousins such as Neanderthals and Denisovans may have given early humans a boost of immunity. Parham says the same kind of cross-species hanky-panky may have played a role in the genetic diversity that he and Moffett discuss in a paper published online by Nature Reviews Immunology.

    "It quite nicely dovetails with all this other stuff," Parham told NBC News. "There is an inherent instability in the way the underlying mechanism works."

    How natural killers work
    The two biologists focus on how particular types of white blood cells, known as natural killer cells, work in the human immune system. In addition to fighting infections and tumors, natural killer cells help regulate the growth of the placenta during pregnancy. Humans are unique among primates in having two variants of the genes that control the receptors for natural killer cells.

    "B haplotypes are favored during reproduction. A haplotypes are more specialized toward defending against infections," Parham explained. "These are subtle effects. On average, if you're an individual that has two A haplotypes and no B haplotype, you're going to have a slightly more robust immune system in terms of dealing with disease."

    Having two B haplotypes, in contrast, would allow for a more robust placenta. That would provide the fetus in the womb with more of the nutrients needed to grow a bigger brain. "In the course of human evolution, you had the evolution of these B haplotypes, which really did enable the brain to get bigger. ... There are correlations between the size of the brain of the baby and these genetic factors," Parham said.

    A detailed analysis of human genetic diversity suggests that the genes for the B haplotype emerged in the time frame lasting from about 7 million years ago to 1.7 million years ago. That would cover a period starting with the divergence of human and chimp ancestors, and ending with the human migration out of Africa.

    The A-vs.-B breakdown is found in all present-day human populations, suggesting that both variants were important to have for different situations. Parham and Moffett speculate that the A variant was important when a population was facing a disease epidemic, while the B variant became important for brain-building once the epidemic passed.

    The role of the birth canal
    When our ancestors began walking upright, that introduced another push-pull effect for brain size. "It's difficult to document, but it's generally thought in the field of obstetrics that birthing is more difficult for humans than it is for other species," Parham said. The dimensions and layout of the human birth canal is one constraint: If a baby's skull were to get significantly bigger, it wouldn't fit through the canal.

    Scientists in Germany have captured the first video of a childbirth using an MRI scanner. TODAY.com's Richard Lui reports.

    Another constraint is pregnancy's effect on the mother's cardiovascular system. In some situations, a potentially fatal condition known as preeclampsia can occur.

    "Part of the compromise is that the human population has tolerated a certain amount of death in childbirth, due to obstructed labor or preeclampsia. ... Both of these types of death in childbirth have been quite common in our species, as has been documented in so many 19th-century novels," Parham said.

    The genetic record indicates that the human species passed through a series of "bottlenecks" in prehistoric times that reduced population diversity to perilously low levels. That's where interbreeding with Neanderthals could have played a part. "One way that modern humans replenished the genetic diversity lost in populations was through the selection of new variants ... another, and possibly more effective, mechanism was to acquire old variants by mating with archaic humans," Parham and Moffett write.

    Today, modern medicine has leveled the evolutionary playing field. But in ancient times, all these genetic and physiological factors seem to have interacted to make our brains what they are today.

    "Basically, we've got the nervous system and the brain putting pressure on the immune system and the reproductive system," Parham said.

    More about human evolution:

    Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

  • Robotic rat with a monkey's smarts to the rescue?

    Mat Evans / University of Sheffield

    A Roomba robot outfitted with whiskers and reprogrammed with monkey smarts determines what type of flooring is beneath it.

    By John Roach, Contributing Writer, NBC News

    The next time you find yourself trapped under a pile of rubble, your savior might be a Roomba — souped-up with whiskers and a monkey brain.

    Such a robot was recently shown to outperform other whiskered robots in characterizing its environment, using technology that could wend its way into next-generation search and rescue robots, the University of Sheffiled reports.

    Researchers have long known that rats sense their environment with whiskers. But models of how their brains interpret these signals vary. 

    One approach, for example, has assumed that rats looked at whisker movement patterns and vibrations over a set period of time and then used that information to make a decision.

    But various robots created with this model, Science Now explains, correctly guessed the floor beneath them only 50 to 80 percent of the time, after 0.4 seconds of exposure.

    Nathan Lepora at the University of Sheffield in England wondered if outfitting these robots with a model of how the monkey brain makes decisions would be an improvement.

    Previous research shows that individual neurons in monkey brains ramp up their firing rates when making decisions about the direction of motion for a group of random dots flashing on a screen.

    A decision is made when the firing of these neurons cross a certain threshold. If the neurons responding to the up motion cross the threshold first, for example, the monkey would say the dots are moving up.

    Lepora and his team fitted a brain model based on this monkey study into an existing Roomba with rat whiskers and found that it nearly flawlessly correctly identified the type of flooring beneath it.

    The findings are reported Jan. 25 in the Journal of the Royal Society Interface.

    In addition to improved rescue robots, the result suggests that rat brains may function similar to those of monkeys — in fact, they "suggest the possibility of a common account of decision-making across mammalian species," the team conclude.

    [Via: Science Now and University of Sheffield]

    More on whiskers, rats, monkeys, and brains:

     

    John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.

     

    Ten years of war have given robot developers a chance to refine and improve their bots. Now the robots are finding all sorts of new jobs on the homefront.