Chapter 16. None
Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.
by Helen Thomson Scared of the dark? Terrified of heights? Spiders make you scream? For the first time, a person's lifelong phobia has been completely abolished overnight. Unfortunately, it required removing a tiny bit of the man's brain, so for now, most people will have to find another way to dispel their fears. The phobia was abolished by accident. A 44-year-old business man started having seizures out of the blue. Brain scans showed he had an abnormality in his left amygdala – an area in the temporal lobe involved in emotional reactions, among other things. Further tests showed the cause was sarcoidosis, a rare condition that causes damage to the lungs, skin and, occasionally, the brain. Doctors decided it was necessary to remove the man's damaged left amygdala. The surgery went well, but soon after the man noticed a strange turn of events. Not only did he have a peculiar "stomach-lurching" aversion to music – which was particularly noticeable when he heard the song accompanying a certain TV advert – but he also discovered he was no longer afraid of spiders. While his aversion to music waned over time, his arachnophobia never returned. Before the surgery he would throw tennis balls at spiders, or use hairspray to immobilise them before vacuuming them up. Now he is able to touch and observe the little critters at close distance and says he actually finds them fascinating. He hasn't noticed any changes to other kinds of fears or anxieties. For example, he is equally as anxious about public speaking now as he was prior to surgery. © Copyright Reed Business Information Ltd.
Link ID: 20265 - Posted: 11.01.2014
By Rachel Feltman Sometimes the process of scientific discovery can be a real headache. In a recent Danish study, scientists were thrilled to give painful migraines to 86 percent of their study subjects. Migraines are a particularly painful mystery for researchers to solve: More than 10 percent of people worldwide are affected by these intense headaches, but no one has been able to pinpoint a specific cause. What makes these headaches, which can cause incapacitating pain and nausea, different from all other headaches? That's why scientists had to make their patients suffer -- researchers keep trying to trigger migraines using different mechanisms. The more successful they are, the more likely it is that the mechanism being tested is actually a common cause of migraines. And once we know what the common causes are, we can try to develop better treatments that target them. In this case the 86 percent "success" rate, which the researchers say is much higher than results with other triggers, was owed to increases of a naturally occurring substance called cyclic AMP, or cAMP. Our bodies use cAMP to dilate blood vessels, so an increase of it can increase the flow of blood. To see if cAMP might cause migraines, the researchers dosed their subjects with cilostazol, a drug that increases cAMP concentrations in the body.
Keyword: Pain & Touch
Link ID: 20264 - Posted: 11.01.2014
by Dan Jones The way your brain reacts to a single disgusting image can be used to predict whether you lean to the left or the right politically. A number of studies have probed the emotions of people along the political spectrum, and found that disgust in particular is tightly linked to political orientation. People who are highly sensitive to disgusting images – of bodily waste, gore or animal remains – are more likely to sit on the political right and show concern for what they see as bodily and spiritual purity, so tend to oppose abortion and gay marriage, for example. A team led by Read Montague, a neuroscientist at Virginia Tech in Roanoke, recruited 83 volunteers and performed fMRI brain scans on them as they looked at a series of 80 images that were either pleasant, disgusting, threatening or neutral. Participants then rated the images for their emotional impact and completed a series of questionnaires that assessed whether they were liberal, moderate or conservative. The brain-imaging results were then fed to a learning algorithm which compared the whole-brain responses of liberals and conservatives when looking at disgusting images versus neutral ones. For both political groups, the algorithm was able to pick out distinct patterns of brain activity triggered by the disgusting images. And even though liberals and conservatives consciously reported similar emotional reactions to the images, the specific brain regions involved and their patterns of activation differed consistently between the two groups – so much so that they represented a neural signature of political leaning, the team concludes. © Copyright Reed Business Information Ltd
Link ID: 20263 - Posted: 11.01.2014
Linda Carroll TODAY contributor For years Larry Hester lived in darkness, his sight stolen by a disease that destroyed the photoreceptor cells in his retinas. But last week, through the help of a “bionic eye,” Hester got a chance to once again glimpse a bit of the world around him. Video: Larry Hester has been without sight for decades, but with the help of a new tool called the "bionic eye," researchers at Duke University have found a way to restore some of his sight. Hester is the seventh patient to receive an FDA-approved device that translates video signals into data the optic nerve can process. The images Hester and others “see” will be far from full sight, but experts hope it will be enough to give a little more autonomy to those who had previously been completely blind. Hester’s doctors at Duke University Eye Center believe that as time goes on the 66-year-old tire salesman from Raleigh, N.C., will be able to “see” more and more. After only five days, there has been remarkable progress. “I hope that [after some practice] he will be able to do things he can’t do today: maybe walk around a little more independently, see doorways or the straight line of a curb. We don’t expect him to be able to make out figures on TV. But we hope he’ll be more visually connected.” said Dr. Paul Hahn, an assistant professor of ophthalmology at the university in Durham.
By Jenna Bilbrey Your starbase is almost complete. All you need is a few more tons of ore. You could take the afternoon to mine it from an asteroid field, but you’ve heard of a Ska’ari who trades ore for cheap. So you message your alliance, use your connections to set up a meeting, and hop in your spacecraft. It’s good to have friends, even if they are virtual. An online science fiction game may not seem like the ideal place to study human behavior, but physicist Stefan Thurner has shown that the way people act in the virtual world isn’t so different from how they act in the real one. Thurner studies all sorts of complex systems at the Medical University of Vienna, so when one of his doctoral students just happened to create one of the most popular free browser-based games in Europe, Thurner suggested using the game, called Pardus, to study the spontaneous organization of people in a closed society. For almost three-and-a-half years, they monitored the interactions of roughly 7000 active players at one time within the game’s virtual world. Unlike in real life, Pardus players’ moves are tracked and their interactions are recorded automatically by the game. “We have information about everything,” Thurner says. “We know who is where at what point in time, … who exchanges things or money with whom, who is friends with whom, … who hates someone else, who collaborates with whom in entrepreneurial activities, who is in a criminal gang with whom, etc. Even though the society is artificial, it’s a human society.” © 2014 American Association for the Advancement of Science.
By Elizabeth Pennisi It’s not such a stretch to think that humans can catch the Ebola virus from monkeys and the flu virus from pigs. After all, they are all mammals with fundamentally similar physiologies. But now researchers have discovered that even a virus found in the lowly algae can make mammals its home. The invader doesn’t make people or mice sick, but it does seem to slow specific brain activities. The virus, called ATCV-1, showed up in human brain tissue several years ago, but at the time researchers could not be sure whether it had entered the tissue before or after the people died. Then, it showed up again in a survey of microbes and viruses in the throats of people with psychiatric disease. Pediatric infectious disease expert Robert Yolken from Johns Hopkins University School of Medicine in Baltimore, Maryland, and his colleagues were trying to see if pathogens play a role in these conditions. At first, they didn't know what ATCV-1 was, but a database search revealed its identity as a virus that typically infects a species of green algae found in lakes and rivers. The researchers wanted to find out if the virus was in healthy people as well as sick people. They checked for it in 92 healthy people participating in a study of cognitive function and found it in 43% of them. What’s more, those infected with the virus performed 10% worse than uninfected people on tests requiring visual processing. They were slower in drawing a line connecting a sequence of numbers randomly placed on a page, for example. And they seemed to have shorter attention spans, the researchers report online today in the Proceedings of the National Academy of Sciences. The effects were modest, but significant. © 2014 American Association for the Advancement of Science
Link ID: 20258 - Posted: 10.29.2014
By ABIGAIL SULLIVAN MOORE The gray matter of the nucleus accumbens, the walnut-shaped pleasure center of the brain, was glowing like a flame, showing a notable increase in density. “It could mean that there’s some sort of drug learning taking place,” speculated Jodi Gilman, at her computer screen at the Massachusetts General Hospital-Harvard Center for Addiction Medicine. Was the brain adapting to marijuana exposure, rewiring the reward system to demand the drug? Dr. Gilman was reviewing a composite scan of the brains of 20 pot smokers, ages 18 to 25. What she and fellow researchers at Harvard and Northwestern University found within those scans surprised them. Even in the seven participants who smoked only once or twice a week, there was evidence of structural differences in two significant regions of the brain. The more the subjects smoked, the greater the differences. Moderate marijuana use by healthy adults seems to pose little risk, and there are potential medical benefits, including easing nausea and pain. But it has long been known that, with the brain developing into the mid-20s, young people who smoke early and often are more likely to have learning and mental health problems. Now researchers suggest existing studies are no longer sufficient. Much of what’s known is based on studies conducted years ago with much less powerful pot. Marijuana samples seized by the federal Drug Enforcement Agency show the concentration of THC, the drug’s psychoactive compound, rising from a mean of 3.75 percent in 1995 to 13 percent in 2013. Potency seesaws depending on the strain and form. Fresh Baked, which sells recreational marijuana in Boulder, Colo., offers “Green Crack,” with a THC content of about 21 percent, and “Phnom Pen,” with about 8 percent. The level in a concentrate called “Bubble Hash” is about 70 percent; cartridges for vaporizers, much like e-cigarettes, range from 15 to 30 percent THC. © 2014 The New York Times Company
By Erin Allday Stanford researchers have found some striking abnormalities in the brains of people with chronic fatigue syndrome, a frustrating and debilitating condition for which there is no known cause and no treatment that’s widely effective. The findings, published Wednesday in the journal Radiology, could improve diagnosis and spark new scientific understanding of the disease. Perhaps even more noteworthy, the results — if they can be confirmed with larger studies — could provide some of the first objective evidence that chronic fatigue syndrome is a severe illness that causes real physiological damage. That would be a major step for patients and their advocates, who still suffer under the stigma of having a condition that for decades was ignored or not taken seriously. “If this finding holds, it will be exciting because yes, we’ve found something that has never been found before. But there’s this additional layer of looking at a disease that was completely ostracized. So there’s also this component of validation,” said Dr. Jose Montoya, an infectious disease specialist who helped establish a chronic fatigue syndrome team at Stanford School of Medicine a decade ago. Montoya was the senior author of the Stanford study. For patients, Montoya said, “It’s almost like we’re saying, 'You were right all along. Hopefully this will put you where you deserve to be, in a real clinic with treatments.’” There are limitations to the study, Montoya said. Most notably, the sample size is fairly small, with 15 chronic fatigue patients and 14 healthy control subjects.
Link ID: 20256 - Posted: 10.29.2014
GrrlScientist Since today is caturday, that wonderful day when the blogosphere takes a breather from hell-raising to celebrate pets, I thought some of my favourite animals: corvids. I ran across this lovely video created by Cornell University’s Laboratory of Ornithology (more fondly referred to as the “Lab of O”) that discusses the differences between and potential meanings of the sounds made by crows and ravens. If you watch birds, even casually, you might be confused by trying to distinguish these two large black corvid species. However, both species are quite chatty, and these birds’ sounds provide important identifying information. In this video, narrated by Kevin McGowan, an ornithologist at the Cornell Lab of O, you’ll learn how to distinguish crows and ravens on the basis of their voices alone. Both crows and ravens make loud raspy signature calls, described as “caw” and “kraa” respectively, but American crows and common ravens have large repertoires of sounds in addition to these calls. They also can learn to imitate the calls of other birds. As you’ll learn in this video, crows often make a “rattle” sound along with their territorial “caw”. They also communicate using a wide variety of other sounds including clicks and bell-like notes. Ravens, on the other hand, produce deep, throaty kraa calls.
Keyword: Animal Communication
Link ID: 20255 - Posted: 10.29.2014
By C. NATHAN DeWALL How many words does it take to know you’re talking to an adult? In “Peter Pan,” J. M. Barrie needed just five: “Do you believe in fairies?” Such belief requires magical thinking. Children suspend disbelief. They trust that events happen with no physical explanation, and they equate an image of something with its existence. Magical thinking was Peter Pan’s key to eternal youth. The ghouls and goblins that will haunt All Hallows’ Eve on Friday also require people to take a leap of faith. Zombies wreak terror because children believe that the once-dead can reappear. At haunted houses, children dip their hands in buckets of cold noodles and spaghetti sauce. Even if you tell them what they touched, they know they felt guts. And children surmise that with the right Halloween makeup, costume and demeanor, they can frighten even the most skeptical adult. We do grow up. We get jobs. We have children of our own. Along the way, we lose our tendencies toward magical thinking. Or at least we think we do. Several streams of research in psychology, neuroscience and philosophy are converging on an uncomfortable truth: We’re more susceptible to magical thinking than we’d like to admit. Consider the quandary facing college students in a clever demonstration of magical thinking. An experimenter hands you several darts and instructs you to throw them at different pictures. Some depict likable objects (for example, a baby), others are neutral (for example, a face-shaped circle). Would your performance differ if you lobbed darts at a baby? It would. Performance plummeted when people threw the darts at the baby. Laura A. King, the psychologist at the University of Missouri who led this investigation, notes that research participants have a “baseless concern that a picture of an object shares an essential relationship with the object itself.” Paul Rozin, a psychology professor at the University of Pennsylvania, argues that these studies demonstrate the magical law of similarity. Our minds subconsciously associate an image with an object. When something happens to the image, we experience a gut-level intuition that the object has changed as well. © 2014 The New York Times Company
Link ID: 20253 - Posted: 10.28.2014
By Melissa Hogenboom Science reporter, BBC News A genetic analysis of almost 900 offenders in Finland has revealed two genes associated with violent crime. Those with the genes were 13 times more likely to have a history of repeated violent behaviour. The authors of the study, published in the journal Molecular Psychiatry, said at least 4-10% of all violent crime in Finland could be attributed to individuals with these genotypes. But they stressed the genes could not be used to screen criminals. Many more genes may be involved in violent behaviour and environmental factors are also known to have a fundamental role. Even if an individual has a "high-risk combination" of these genes the majority will never commit a crime, the lead author of the work Jari Tiihonen of the Karolinska Institutet in Sweden said. "Committing a severe, violent crime is extremely rare in the general population. So even though the relative risk would be increased, the absolute risk is very low," he told the BBC. The study, which involved analysis of almost 900 criminals, is the first to have looked at the genetic make-up of so many violent criminals in this way. Warrior gene Each criminal was given a profile based on their offences, categorising them into violent or non-violent. The association between genes and previous behaviour was strongest for the 78 who fitted the "extremely violent offender" profile. This group had committed a total of 1,154 murders, manslaughters, attempted homicides or batteries. A replication group of 114 criminals had all committed at least one murder. BBC © 2014
Daniel Duane, Men's Journal For more than half a century, the conventional wisdom among nutritionists and public health officials was that fat is dietary enemy No. 1 — the leading cause of obesity and heart disease. It appears the wisdom was off. And not just off. Almost entirely backward. According to a new study from the National Institutes of Health, a diet that reduces carbohydrates in favor of fat — including the saturated fat in meat and butter — improves nearly every health measurement, from reducing our waistlines to keeping our arteries clear, more than the low-fat diets that have been recommended for generations. "The medical establishment got it wrong," says cardiologist Dennis Goodman, director of Integrative Medicine at New York Medical Associates. "The belief system didn't pan out." It's not the conclusion you would expect given the NIH study's parameters. Lead researcher Lydia Bazanno, of the Tulane University School of Public Health, pitted this high-fat, low-carb diet against a fat-restricted regimen prescribed by the National Cholesterol Education Program. "We told both groups to get carbs from green, leafy vegetables, because those are high in nutrients and fiber to keep you sated," Bazanno says. "We also told everyone to stay away from trans fats." The fat-restricted group continued to eat carbs, including bread and cereals, while keeping saturated fat — common in animal products — below 7 percent of total calories. By contrast, the high-fat group cut carbs in half and did not avoid butter, meat, and cheese. Most important, both groups ate as much as they wanted — no calorie counting, no going hungry.
Link ID: 20251 - Posted: 10.28.2014
By Eric Niiler Has our reliance on iPhones and other instant-info devices harmed our memories? Michael Kahana, a University of Pennsylvania psychology professor who studies memory, says maybe: “We don’t know what the long-lasting impact of this technology will be on our brains and our ability to recall.” Kahana, 45, who has spent the past 20 years looking at how the brain creates memories, is leading an ambitious four-year Pentagon project to build a prosthetic memory device that can be implanted into human brains to help veterans with traumatic brain injuries. He spoke by telephone with The Post about what we can do to preserve or improve memory. Practicing the use of your memory is helpful. The other thing which I find helpful is sleep, which I don’t get enough of. As a general principle, skills that one continues to practice are skills that one will maintain in the face of age-related changes in cognition. [As for all those brain games available], I am not aware of any convincing data that mental exercises have a more general effect other than maintaining the skills for those exercises. I think the jury is out on that. If you practice doing crossword puzzles, you will preserve your ability to do crossword puzzles. If you practice any other cognitive skill, you will get better at that as well. Michael Kahana once could name every student in a class of 100. Now, says the University of Pennsylvania psychology professor who studies memory, “I find it too difficult even with a class of 20.” (From Michael Kahana)
Keyword: Learning & Memory
Link ID: 20249 - Posted: 10.28.2014
With the passing away of Professor Allison Doupe on Friday, October 24, of cancer, UCSF and biomedical science have lost a scholar of extraordinary intelligence and erudition and a campus leader. Allison Doupe was a psychiatrist and systems neuroscientist who became a leader of her field, the study of sensorimotor learning and its neural control. Allison was recruited to the Departments of Psychiatry and Physiology and the Neuroscience Graduate Program in 1993, rising to Professor in 2000. Her academic career has been outstanding at every stage, including First Class Honors at McGill, an MD and PhD in Neurobiology from Harvard, and a prestigious Junior Fellowship from the Harvard University Society of Fellows. Her PhD work with Professor Paul Patterson definitively established the role of particular environmental factors in the development of autonomic neurons and was important in the molecular and cellular investigations of the roles of hormones and growth factors in that system. After internship at the Massachusetts General Hospital and residency in psychiatry at UCLA, she chose to pursue a postdoctoral fellowship at Caltech, studying song learning in birds with Professor Mark Konishi as a way of combining her clinical interests in behavior and development with research in cognitive neuroscience. The development of birdsong is in many important respects similar to language development in humans. The pioneering work of Peter Marler, on song sparrows in Golden Gate Park, showed that each baby songbird learns its father’s dialect but could readily learn the dialect of any singing bird of the same species placed in the role of tutor. Many birds, including the ones studied by Allison Doupe, learn their song by listening to their father sing during a period of life in which they are not themselves singing, and they later practice and perfect their own song by comparison with their memory of the father’s (or tutor’s) song.
By PAM BELLUCK Science edged closer on Sunday to showing that an antioxidant in chocolate appears to improve some memory skills that people lose with age. In a small study in the journal Nature Neuroscience, healthy people, ages 50 to 69, who drank a mixture high in antioxidants called cocoa flavanols for three months performed better on a memory test than people who drank a low-flavanol mixture. On average, the improvement of high-flavanol drinkers meant they performed like people two to three decades younger on the study’s memory task, said Dr. Scott A. Small, a neurologist at Columbia University Medical Center and the study’s senior author. They performed about 25 percent better than the low-flavanol group. “An exciting result,” said Craig Stark, a neurobiologist at the University of California, Irvine, who was not involved in the research. “It’s an initial study, and I sort of view this as the opening salvo.” He added, “And look, it’s chocolate. Who’s going to complain about chocolate?” The findings support recent research linking flavanols, especially epicatechin, to improved blood circulation, heart health and memory in mice, snails and humans. But experts said the new study, although involving only 37 participants and partly funded by Mars Inc., the chocolate company, goes further and was a well-controlled, randomized trial led by experienced researchers. Besides improvements on the memory test — a pattern recognition test involving the kind of skill used in remembering where you parked the car or recalling the face of someone you just met — researchers found increased function in an area of the brain’s hippocampus called the dentate gyrus, which has been linked to this type of memory. © 2014 The New York Times Company
Keyword: Learning & Memory
Link ID: 20246 - Posted: 10.27.2014
By Michael Hedrick I have a hard time making friends. Getting to trust people well enough to call them a friend takes a lot of work. It’s especially hard when you are living with schizophrenia and think everyone is making fun of you. Schizophrenia is the devil on your shoulder that keeps whispering in your ear and, no matter what you try, the little demon won’t stop. He hasn’t stopped in the almost nine years I’ve lived with the illness, and he’s not about to stop now. He’s just quieted down a bit. I’d call him my companion but that would imply a degree of friendship, and there’s no way in hell I’m the little devil’s friend. I have plenty of acquaintances, and a couple hundred “friends” on Facebook. But real friends, mostly family, I can count on one hand. For me, making friends is like climbing a vertical rock wall with no ropes, requiring a degree of thrill-seeking, and a good deal of risk. For someone to be my friend, they have to accept that I’m crazy, and even getting to the point of telling them that is daunting when all you hear is the devil’s whispering that they’re making snap judgments about you or will be going back to their real friends and laughing about you. But interestingly, in my efforts to make friends, coffee shops have helped. The simple routine of going to get your fix of liquid energy every day provides a sort of breeding ground for community. You see these people every day,whether you like it or not and, over time, friendships form. I used to live in a small town called Niwot, about five miles down the highway from Boulder, where I now live. Every morning around 6 I would go to Winot Coffee, the small independent coffee shop, and every morning, without fail, there was a guy my age sitting outside with his computer smoking clove cigarettes. Given the regularity of seeing him every morning, and given that we were some of the only 20-somethings in town, we got to talking. © 2014 The New York Times Company
Link ID: 20240 - Posted: 10.25.2014
By J. PEDER ZANE Striking it rich is the American dream, a magnetic myth that has drawn millions to this nation. And yet, a countervailing message has always percolated through the culture: Money can’t buy happiness. From Jay Gatsby and Charles Foster Kane to Tony Soprano and Walter White, the woefully wealthy are among the seminal figures of literature, film and television. A thriving industry of gossipy, star-studded magazines and websites combines these two ideas, extolling the lifestyles of the rich and famous while exposing the sadness of celebrity. All of which raises the question: Is the golden road paved with misery? Yes, in a lot of cases, according to a growing body of research exploring the connection between wealth and happiness. Studies in behavioral economics, cognitive psychology and neuroscience are providing new insights into how a changing American economy and the wiring of the human brain can make life on easy street feel like a slog. Make no mistake, it is better to be rich than poor — psychologically as well as materially. Levels of depression, anxiety and stress diminish as incomes rise. What has puzzled researchers is that the psychological benefits of wealth seem to stop accruing once people reach an income of about $75,000 a year. “The question is, What are the factors that dampen the rewards of income?” said Scott Schieman, a professor of sociology at the University of Toronto. “Why doesn’t earning even more money — beyond a certain level — make us feel even happier and more satisfied?” The main culprit, he said, is the growing demands of work. For millenniums, leisure was wealth’s bedfellow. The rich were different because they worked less. The tables began to turn in America during the 1960s, when inherited privilege gave way to educational credentials and advancement became more closely tied to merit. © 2014 The New York Times Company
Link ID: 20236 - Posted: 10.23.2014
by Helen Thomson For the first time, doctors have opened and closed the brain's protector – the blood-brain barrier – on demand. The breakthrough will allow drugs to reach diseased areas of the brain that are otherwise out of bounds. Ultimately, it could make it easier to treat conditions such as Alzheimer's and brain cancer. The blood-brain barrier (BBB) is a sheath of cells that wraps around blood vessels (in black) throughout the brain. It protects precious brain tissue from toxins in the bloodstream, but it is a major obstacle for treating brain disorders because it also blocks the passage of drugs. Several teams have opened the barrier in animals to sneak drugs through. Now Michael Canney at Paris-based medical start-up CarThera, and his colleagues have managed it in people using an ultrasound brain implant and an injection of microbubbles. When ultrasound waves meet microbubbles in the blood, they make the bubbles vibrate. This pushes apart the cells of the BBB. With surgeon Alexandre Carpentier at Pitié-Salpêtrière Hospital in Paris, Canney tested the approach in people with a recurrence of glioblastoma, the most aggressive type of brain tumour. People with this cancer have surgery to remove the tumours and then chemotherapy drugs, such as Carboplatin, are used to try to kill any remaining tumour cells. Tumours make the BBB leaky, allowing in a tiny amount of chemo drugs: if more could get through, their impact would be greater, says Canney. © Copyright Reed Business Information Ltd.
Keyword: Brain imaging
Link ID: 20235 - Posted: 10.23.2014
David DiSalvo @neuronarrative One of the lively debates spawned from the neuroscience revolution has to do with whether humans possess free will, or merely feel as if we do. If we truly possess free will, then we each consciously control our decisions and actions. If we feel as if we possess free will, then our sense of control is a useful illusion—one that neuroscience will increasingly dispel as it gets better at predicting how brain processes yield decisions. For those in the free-will-as-illusion camp, the subjective experience of decision ownership is not unimportant, but it is predicated on neural dynamics that are scientifically knowable, traceable and—in time—predictable. One piece of evidence supporting this position has come from neuroscience research showing that brain activity underlying a given decision occurs before a person consciously apprehends the decision. In other words, thought patterns leading to conscious awareness of what we’re going to do are already in motion before we know we’ll do it. Without conscious knowledge of why we’re choosing as we’re choosing, the argument follows, we cannot claim to be exercising “free” will. Those supporting a purer view of free will argue that whether or not neuroscience can trace brain activity underlying decisions, making the decision still resides within the domain of an individual’s mind. In this view, parsing unconscious and conscious awareness is less important than the ultimate outcome – a decision, and subsequent action, emerging from a single mind. If free will is drained of its power by scientific determinism, free-will supporters argue, then we’re moving down a dangerous path where people can’t be held accountable for their decisions, since those decisions are triggered by neural activity occurring outside of conscious awareness. Consider how this might play out in a courtroom in which neuroscience evidence is marshalled to defend a murderer on grounds that he couldn’t know why he acted as he did.
Link ID: 20232 - Posted: 10.23.2014
Carl Zimmer Scientists have reconstructed the genome of a man who lived 45,000 years ago, by far the oldest genetic record ever obtained from modern humans. The research, published on Wednesday in the journal Nature, provided new clues to the expansion of modern humans from Africa about 60,000 years ago, when they moved into Europe and Asia. And the genome, extracted from a fossil thighbone found in Siberia, added strong support to a provocative hypothesis: Early humans interbred with Neanderthals. “It’s irreplaceable evidence of what once existed that we can’t reconstruct from what people are now,” said John Hawks, a paleoanthropologist at the University of Wisconsin who was not involved in the study. “It speaks to us with information about a time that’s lost to us.” The discoveries were made by a team of scientists led by Svante Paabo, a geneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Over the past three decades, Dr. Paabo and his colleagues have developed tools for plucking out fragments of DNA from fossils and reading their sequences. Early on, the scientists were able only to retrieve tiny snippets of ancient genes. But gradually, they have invented better methods for joining the overlapping fragments together, assembling larger pieces of ancient genomes that have helped shed light on the evolution of humans and their relatives. In December, they published the entirety of a Neanderthal genome extracted from a single toe bone. Comparing Neanderthal to human genomes, Dr. Paabo and his colleagues found that we share a common ancestor, which they estimated lived about 600,000 years ago. © 2014 The New York Times Company
Link ID: 20231 - Posted: 10.23.2014