302 posts tagged Brain
Scientists say a part of the brain, smaller than a pea, triggers the instinctive feeling that something bad is about to happen. Writing in the journal PNAS, they suggest the habenula plays a key role in how humans predict, learn from and respond to nasty experiences. And they question whether hyperactivity in this area is responsible for the pessimism seen in depression. They are now investigating whether the structure is involved in the condition.
Money or shock
Animal studies have shown that the habenula fires up when subjects expect or experience adverse events, But in humans this tiny structure (less than 3mm in diameter) has proved difficult to see on scans.
Inventing a technique to pinpoint the area, scientists at University College London put 23 people though MRI scanners to monitor their brain activity.
Participants were shown a range of abstract pictures. A few seconds later, the images were linked to either punishment (painful electric shocks), reward (money) or neutral responses.
For some images, a punishment or reward followed each time but for others this varied - leaving people uncertain whether they were going to feel pain or not.
And when people saw pictures associated with shocks the habenula lit up.
And the more certain they were a picture was going to result in a punishment, the stronger and faster the activity in this area.
Scientists suggests the habenula is involved in helping people learn when it is best to stay away from something and may also signal just how bad a nasty event is likely to be.
Antonio Damasio, M.D., is a professor of neuroscience and the director of the Brain and Creativity Institute at the University of Southern California. He is a pioneer in the field of cognitive neuroscience and a highly cited researcher. He has received numerous awards for his contributions to the understanding of emotions, feelings and decision-making, and he has described his discoveries in several books.
Walking the halls here at the Brain and Creativity Institute, I see art works from your personal collection, and downstairs there is a theater that is also used as a recording studio. How are you furthering the understanding of the connection between the brain and the arts?
As you come through the lobby, if you turn right, you go toward a laboratory of electrophysiology and a state-of-the-art 3-D MR brain scanner. If you turn left, you go into a small, state-of-the-art auditorium. Its acoustics were designed by Yasuhisa Toyota, who is responsible for the sound of some of the greatest music halls around the world from Tokyo to Hamburg, including the Walt Disney Concert Hall here in LA, a landmark collaboration with Frank Gehry. What we wanted when we created this complex is to literally force people to say, “What an odd combination. Why?” So here is the answer. On the one hand, we have the most modern form of inquiring into the brain-making mind, and, on the other, we have the oldest. Because when people were beginning to do theater, music and recitations of poetry, say, in an arena in Greece, they were in fact inquiring about the human mind in very probing ways. Great culture — philosophy, theater, music — gave us some of the most remarkable first entries into the human mind. We wanted to have these two approaches together to force those who work here as well as visitors to see that they’re not that different — that the mission we pursue now is not that different from the mission that Sophocles or Aristotle pursued. We need to bridge the two approaches and keep respecting the achievements of the past. The idea that by just doing neuroscience or advanced cognitive science, one can understand everything about the human mind is ridiculous. We need to bring past efforts in the arts and the humanities into the mix and also use the current contributions of artists and philosophers to understand this most complicated process that is the human mind.
“I think I’ve only spent about ten percent of my energies on writing,” Pulitzer Prize-winning writer Katherine Anne Porter confessed in a 1963 interview. “The other ninety percent went to keeping my head above water.” While art may be a form of therapy for the rest of us, Porter’s is a sentiment far from uncommon among the creatively gifted who make that art. Why? When Nancy Andreasen took a standard IQ test in kindergarten, she was declared a “genius.” But she was born in the late 1930s, an era when her own mother admonished that no one would marry a woman with a Ph.D. Still, became a psychiatrist and a neuroscientist, and made understanding the brain’s creative capacity her life’s work. Having grown up seeped in ambivalence about her “diagnosis” of extraordinary intellectual and creative ability, Andreasen wondered about the social forces at work in the nature-nurture osmosis of genius, about how many people of natural genius were born throughout history whose genius was never manifested, suppressed by lack of nurture. “Half of the human beings in history are women,” she noted, “but we have had so few women recognized for their genius. How many were held back by societal influences, similar to the ones I encountered and dared to ignore?” (One need only look at the case of Benjamin Franklin and his sister to see Andreasen’s point.)
Humans Already Use Way, Way More Than 10 Percent of Their Brains
It’s a complex, constantly multi-tasking network of tissue—but the myth persists.
By now, perhaps you’ve seen the trailer for the new sci-fi thriller Lucy. It starts with a flurry of stylized special effects and Scarlett Johansson serving up a barrage of bad-guy beatings. Then comes Morgan Freeman, playing a professorial neuroscientist with the obligatory brown blazer, to deliver the film’s familiar premise to a full lecture hall: “It is estimated most human beings only use 10 percent of the brain’s capacity. Imagine if we could access 100 percent. Interesting things begin to happen.” Johansson as Lucy, who has been kidnapped and implanted with mysterious drugs, becomes a test case for those interesting things, which seem to include even more impressive beatings and apparently some kind of Matrix-esque time-warping skills. Of course, the idea that “you only use 10 percent of your brain” is, indeed, 100 hundred percent bogus. Why has this myth persisted for so long, and when is it finally going to die? (via Humans Already Use Way, Way More Than 10 Percent of Their Brains - Sam McDougle - The Atlantic)
Watch this: My Mind’s Eye: A Series of Video Interviews on Mind and Brain.
Episode 2 - How Free Is Your Will? An interview with Michael Gazzaniga
Professor of Psychology and the Director for the SAGE Center for the Study of Mind at the University of California Santa Barbara
© 2014 Imaginal Disc
Host: Joseph LeDoux.
Writer-Director: Alexis Gambis.
Last week, nine-year-old Hally Yust died after contracting a rare brain-eating amoeba infection while swimming near her family’s home in Kansas. The organism responsible, Naegleria fowleri, dwells in warm freshwater lakes and rivers and usually targets children and young adults. Once in the brain it causes a swelling called primary meningoencephalitis. The infection is almost universally fatal: it kills more than 97 percent of its victims within days. Although deadly, infections are exceedingly uncommon—there were only 34 reported in the U.S. during the past 10 years—but evidence suggests they may be increasing. Prior to 2010 more than half of cases came from Florida, Texas and other southern states. Since then, however, infections have popped up as far north as Minnesota. “We’re seeing it in states where we hadn’t seen cases before,” says Jennifer Cope, an epidemiologist and expert in amoeba infections at the U.S. Centers for Disease Control and Prevention. The expanding range of Naegleria infections could potentially be related to climate change, she adds, as the organism thrives in warmer temperatures. “It’s something we’re definitely keeping an eye on.” Still, “when it comes to Naegleria there’s a lot we don’t know,” Cope says—including why it chooses its victims. The amoeba has strategies to evade the immune system, and treatment options are meager partly because of how fast the infection progresses. But research suggests that the infectioncan be stopped if it is caught soon enough. So what happens during an N. fowleri infection? The microscopic amoebae, which can be suspended in water or nestled in soil, enter the body when water goes up the nose. After attaching to the mucous membranes in the nasal cavity, N. fowleri burrows into the olfactory nerve, the structure that enables our sense of smell and leads directly to the brain. It probably takes more than a drop of liquid to trigger a Naegleria infection; infections usually occur in people who have been engaging in water sports or other activities that may forcefully suffuse the nose with lots of water—diving, waterskiing, wakeboarding, and in one case a baptism dunking.
ARE we ever going to figure out how the brain works? After decades of research, diseases like schizophrenia and Alzheimer’s still resist treatment. Despite countless investigations into serotonin and other neurotransmitters, there is still no method to cure clinical depression. And for all the excitement about brain-imaging techniques, the limitations of fMRI studies are, as evidenced by popular books like “Brainwashed” and “Neuromania,” by now well known. In spite of the many remarkable advances in neuroscience, you might get the sinking feeling that we are not always going about brain science in the best possible way.
This feeling was given prominent public expression on Monday, when hundreds of neuroscientists from all over the world issued an indignant open letter to the European Commission, which is funding the Human Brain Project, an approximately $1.6 billion effort that aims to build a complete computer simulation of the human brain. The letter charges that the project is “overly narrow” in approach and not “well conceived.” While no neuroscientist doubts that a faithful-to-life brain simulation would ultimately be tremendously useful, some have called the project “radically premature.” The controversy serves as a reminder that we scientists are not only far from a comprehensive explanation of how the brain works; we’re also not even in agreement about the best way to study it, or what questions we should be asking.
Love is the drug, scientists find
Cambridge University scientists find that those with drug addiction and sex addiction have similar neurological responses
When Roxy Music star Bryan Ferry declared that ”love is the drug” he may have been speaking the truth. Cambridge University scientists have found that sex and drug addiction may be two sides of the same neurological coin. When diagnosed sex addicts looked at explicit sexual images, it triggered brain activity very similar to that seen in people dependent on drugs. But the researchers caution that this does not suggest pornography is generally addictive. Lead scientist Dr Valerie Voon, from Cambridge University, said: ”The patients in our trial were all people who had substantial difficulties controlling their sexual behaviour and this was having significant consequences for them, affecting their lives and relationships. ”In many ways, they show similarities in their behaviour to patients with drug addictions. We wanted to see if these similarities were reflected in brain activity, too. ”There are clear differences in brain activity between patients who have compulsive sexual behaviour and healthy volunteers. These differences mirror those of drug addicts.” Previous studies have suggested that up to one in 25 adults may be affected by an obsession with sexual thoughts, feelings or behaviour they are unable to control. Public awareness of sex addiction has been raised by celebrities seeking help for the problem, including actors Michael Douglas and David Duchovny. The Cambridge scientists recruited 19 male sex addicts and played them short videos featuring either explicit pornographic scenes or people engaged in exciting sports such as skiing or skydiving. At the same time, the men’s brain activity was monitored using a functional magnetic resonance imaging (fMRI) scanner. The experiment was repeated with a matched group of volunteers not affected by sex addiction. Three regions of the brain were found to be especially more active in the brains of the sex addicts than in the healthy volunteers, the ventral striatum, dorsal anterior cingulate and amygdala. All three are also known to be activated in drug addicts stimulated by the sight of drug-taking paraphernalia. (via Love is the drug, scientists find - Telegraph)
ONE moment you’re conscious, the next you’re not. For the first time, researchers have switched off consciousness by electrically stimulating a single brain area. Scientists have been probing individual regions of the brain for over a century, exploring their function by zapping them with electricity and temporarily putting them out of action. Despite this, they have never been able to turn off consciousness – until now. Although only tested in one person, the discovery suggests that a single area – the claustrum – might be integral to combining disparate brain activity into a seamless package of thoughts, sensations and emotions. It takes us a step closer to answering a problem that has confounded scientists and philosophers for millennia – namely how our conscious awareness arises. Many theories abound but most agree that consciousness has to involve the integration of activity from several brain networks, allowing us to perceive our surroundings as one single unifying experience rather than isolated sensory perceptions. One proponent of this idea was Francis Crick, a pioneering neuroscientist who earlier in his career had identified the structure of DNA. Just days before he died in July 2004, Crick was working on a paper that suggested our consciousness needs something akin to an orchestra conductor to bind all of our different external and internal perceptions together. With his colleague Christof Koch, at the Allen Institute for Brain Science in Seattle, he hypothesised that this conductor would need to rapidly integrate information across distinct regions of the brain and bind together information arriving at different times. For example, information about the smell and colour of a rose, its name, and a memory of its relevance, can be bound into one conscious experience of being handed a rose on Valentine’s day.
The pair suggested that the claustrum – a thin, sheet-like structure that lies hidden deep inside the brain – is perfectly suited to this job (Philosophical Transactions of The Royal Society B, doi.org/djjw5m).