Showing posts with label neuroscience. Show all posts
Showing posts with label neuroscience. Show all posts

Tuesday, March 31, 2015

How your brain can heal itself

The brain is actually a supple, malleable organ, as ready to unlearn as it is to learn, capable of transforming vicious circles into virtuous circles, of resetting & repairing its internal communications. Far more than once dreamed possible, the brain can—if not always cure—heal itself.
 
Doidge wrote about the brain’s remarkable ability to recalibrate itself—what doctors call neuroplasticity—in his 2007 bestseller The Brain That Changes Itself. His new book recounts an astounding array of radical improvements in brain problems long thought irreversible. There are newly effective therapies, leading to improvement in, & sometimes even complete cures, for conditions ranging from stroke to traumatic brain injuries, learning disorders & missing brain parts. Even Parkinson’s & MS symptoms can be improved in new ways. “Like Marshall McLuhan said, the future is already here,” says Doidge in an interview. “The early neuroplasticians had to battle to get their findings accepted but now the field is not remotely controversial. I’m no longer talking about ‘promising’ developments down the road, but therapies that are here now. Patients & their caregivers just have to know who is doing things they thought impossible.”

Consider Dr. Michael Moskowitz, who knows pain both professionally & intimately. The co-operator of Bay Area Medical Associates in Sausalito, Calif., Moskowitz is a star in the treatment of pain, the man who sets the exams in pain medicine for aspiring American doctors. ... “We are where people come to die with their pain,” he told Doidge. By 2007, 13 years after a waterskiing accident, it looked like Moskowitz would be one of them. The acute pain from his neck injury had morphed into permanent, & growing, chronic pain.
 
It did so via the same mechanisms that create that transformation in anyone. “Chronic pain is plasticity gone wild,” Doidge says. The injury to Moskowitz’s neck had also affected his body’s pain system, specifically the neurons in the brain associated with the neck area, causing them to fire repeated false alarms long after the neck had healed. What happened next illustrates core laws of neuroplasticity. Neurons that fire together, wire together: the more Moskowitz’s pain signals flared, the better & quicker they became at it. Use it or lose it: the fight for brain territory is competitive. The more Moskowitz favoured his neck because of the pain, the less the neurons involved with it had to do, & the more vulnerable they become to hijacking by nearby areas, including the pain sensors now working overtime. Moskowitz was caught in a vicious circle. His pain, 3/10 on the standard scale at the best of times, & spiking frequently to 8/10, was only getting worse. “Plasticity is a blessing when you’re listening to classical music & developing an appreciation for it,” Doidge wryly notes, “but it’s a curse when you are reinforcing pain.”

As his quality of life inexorably eroded, Moskowitz sat down to read 15,000 pages of cutting-edge neurological research, seeking a way to make plasticity work for him. Moskowitz concentrated on 2 areas of the brain among the dozen that do at least some pain processing, the posterior cingulate & the posterior parietal lobe, areas whose primary purpose is to deal with visual information.
 
He knew already that when a brain area is processing pain it uses about 5% of the neurons in the area, but the reinforcement involved in chronic pain means about 15% - 20% of the neurons become involved. By concentrating on an image of his brain—an image in which it changed from being lit up by pain activity to being calm & pain-free—Moskowitz thought he could quiet the original pain receptors & force the hijacked neurons back to their day jobs as visual processors.
 
It required relentless dedication at first, a conscious response to every twinge. In 3 weeks, Moskowitz thought he detected slight improvement, enough to spur him on; by 6 weeks the pain that had spread to his back was gone; within a year he was almost always pain-free everywhere. He had turned the vicious circle virtuous. “Relentlessness was the most important factor, absolutely,” Doidge agrees. “As a psychiatrist, I know that if you reframe a symptom attack as an opportunity, if instead of becoming crestfallen & pulling back, you treat every pain, anxiety or inhibition—reframe it as your moment—that’s the route to altering that circuitry. That’s what Moskowitz did. He didn’t let a single twinge of pain go by.”

Intense dedication is a hallmark of those who, all on their own, accomplish large-scale change in their brains. John Pepper, a South African now in his late seventies, was diagnosed in his thirties with the incurable, chronic, progressive neurodegenerative disease known as Parkinson’s. By all odds he should be immobile, if not dead, by now, but Pepper has fought his symptoms to a standstill by vigorous exercise carried out with ferocious determination & conscientious attention to detail. “Even as his unconscious ability to walk unravelled,” Doidge explains, “Pepper realized that if he analyzed how he walked & used his conscious mind to guide him, he could still do it. So he used a different part of his brain, the frontal lobes, &—like a child learning to walk—thought himself into efficient walking.”

People with Parkinson’s have 6 times the dementia rate of those who do not, & Pepper is reaching what are the danger years for anyone, yet his mind is sharp. That, together with his mode of exercise & the first-the-right-heel-then-the-left-knee precision with which he pursues it, raise a question about Alzheimer’s, a disease where both exercise & conscientiousness are proven factors in delaying onset. Is Alzheimer’s a disease of plasticity, or rather of its absence? Doidge is cautious in response. “There are so many ways of looking at Alzheimer’s. Most researchers analyze it chemically, because of the proteins involved, in hopes of finding alleviating drugs, but to look at Alzheimer’s that way is to put it under the microscope at very high power—it is more holistic to think of an Alzheimer’s brain as one that is losing plasticity.”

Whether walking battles the onset of dementia through its link to plasticity or by its more general health benefits, it’s one of the most potent anti-dementia forces known. “Now we have the Cardiff study looking at the British men over 30 years & it shows that if you did 5 things, including walking at least 3 kilometres a day,” Doidge says, “the risk of dementia falls a staggering 60%. If any medication did that, it would be the most talked-about drug in history.”

Not that drugs have any role in the story Doidge tells. Moskowitz, who has switched the goal of his clinic from pain management to pain eradication, recognizes that he himself (& the likes of Pepper) is an outlier set apart by his iron determination. Not all his patients can follow him down his own relentless road. Even so, Moskowitz does not always seek to aid them with drug therapy—instead devoting considerable effort to weaning them from painkillers—but with touch, sound & vibration. It’s a pattern Doidge sees everywhere. “Almost all the success stories involve a combination of mind & energy.”

Much of The Brain’s Way of Healing is devoted to non-invasive energy therapies. The author is particularly enamoured with light therapy, once far more prominent in Western medicine than it is now. Doidge likes to quote Florence Nightingale, who said “Light is not only a painter but a sculptor,” after she took note that wounded soldiers in outdoor field hospitals in Crimea recovered better than those stuck indoors. “We are far more transparent than we think & more sensitive to light than we think. So I have an entire chapter on the use of light, including cold lasers, to heal the brain.”

Light and other energy therapies have fallen from favour, Doidge believes, because for 50 years scientists have focused on the brain’s material & chemical side. Chemicals do work in small regions for signalling, he says, but the true universal language of the brain lies in its pattern of electrical signals. “All our senses take energy from outside & translate it into another form of energy inside the brain. Clinicians can now use these natural forms of energy to ‘talk’ to the brain.” And nothing speaks more loudly and clearly than the electrical pulses of the PoNS.
 
Originally thought of by its inventors as an aid for brain-injured people with balance troubles, the Portable Neuromodulation Stimulator has astonished even them with its effectiveness over a range of conditions &, especially, the speed with which it helps. A small, pocket-sized device, part of which went into the mouth & rested on the tongue & part of which stayed outside—144 electrodes that fired off electric pulses to activate the tongue’s sensory neurons. After 2 weeks of sessions with it, a voiceless MS patient could sing; a woman immobilized by Parkinson’s could walk; a stroke victim who couldn’t understand a newspaper article could read whatever she wanted.
 
All this because the tongue, Doidge says, “is the royal road to the brain”—with no dead skin & a moist surface making it an excellent conductor, & rich in sensory preceptors for touch, taste & pain that lead directly to the brain stem. “The PoNS turned out to be a very good stimulator for the whole brain.” Doidge thinks it clears up “noise” in the brain caused by disease or injury. “People tend to think neurons are either dead or alive afterwards, but actually many are firing at an irregular or wrong rate. Incoming information is thus chaotic & noise-filled, with even the healthy cells unable to communicate.” The PoNs, via the tongue’s access to the brain stem & hence the entire brain, can reset the circuitry, allow effective electrical communication & return the brain to a state of equilibrium. That’s why the application is so wide-ranging: with the noise gone, the brain starts working with what it has, in whatever condition it finds itself.
 
For decades, Doidge remarks, scientists wouldn’t use “healing” & “brain” in the same sentence, because they thought the brain was so sophisticated that it lacked self-healing powers. That turned out to be wrong—the brain is even more sophisticated than anyone realized.

Thursday, March 12, 2015

Inside Your Teenager's Scary Brain

Teen years always the most troubling & scary part of our years. Although, this article is a good one, every parent has a different way & experience of bringing up their teen through those difficult years. Some pass with flying colours, while others crash & burn. Every parent has their own story & wisdom to pass on to other parents. What actually works is different for everyone. But then, it never hurts to learn from others, either, or at least keep these thoughts in the back of one's mind.
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Conventional wisdom has long held that our brains are largely developed by puberty. However, research in the past 10-15 years has shown that our brains continue to develop in fundamental ways through the teen years & even into the late 20s & 30s. In fact, Jensen argues in her new book, The Teenage Brain: A Neuroscientist’s Survival Guide to Raising Adolescents & Young Adults, the teenage years comprise one of the brain’s most critical periods for development—likely every bit as crucial as early childhood. “That 7 years in their life is, in a way, as important as their first 7 years of life,” Jensen says. “It is probably one of the most important 7-year [periods] in their entire life.”


Among the most popular misconceptions about brain development is the idea that the most important changes happen in the first 3 years of life. This “myth of three,” has been the source of intense parental anxiety over the fear that “adults are in a race against time to provide stimulation to their infants before their synapses are lost,” writes Paul Howard-Jones, a professor of neuroscience & education at the University of Bristol in the journal Nature. ... Behind the seemingly invincible teenage boy with the booming voice & adult body is a brain that is still incredibly vulnerable to everything from sports-related concussions to mental illness & addiction. New research is uncovering ways in which the activities that so often typify teenage years, such as experimenting with cigarettes & marijuana & alcohol, can lower a teen’s IQ or increase susceptibility to mental illness later on. Chronic stress stemming from family violence, poverty or bullying has also been linked to changes in the teen brain that can raise the risk of mood disorders or learning disabilities.
 
At the heart of our understanding of brain development are 2 basic concepts: grey matter & white matter. Grey matter consists of neurons, the brain cells that form the building blocks of the brain. White matter, axons, are the connections that form between grey matter, helping to move information from one area of the brain to the next.
 
While grey-matter growth is indeed almost completely finished by the age of 6, white matter—the wiring between brain cells—continues to develop well into the 20s. In fact, says Jensen, that wiring is only about 80% complete by the age of 18.
 
Along with new wiring, the brains of teens & young adults are also undergoing a process called myelination, in which those white-matter connections are being coated in a protective fatty material. Myelin acts as a form of insulation, allowing signals to move faster between brain cells, helping to speed the flow of information in the brain. Since both the wiring to the prefrontal cortex, & the insulation, is incomplete, teens often take longer to access their prefrontal cortexes, meaning they have a harder time making accurate judgments & controlling their impulses. The process of myelination continues into the 30s, giving rise to questions about how old someone must be to be considered to have a fully developed “adult” brain.
 
At the same time that teens’ brains are laying down connections & insulation, puberty has triggered pituitary glands to release hormones that are acting on the limbic system, the brain’s emotional centre. The combination of heightened emotions & an underdeveloped prefrontal cortex explains why teens are often prone to emotional outbursts, says Jensen, & also why they seek out more emotionally charged situations, from sad movies to dangerous driving.
 
Hormones also appear to have a different effect in teens than they do in adults. The hormone THP, which is released by the body in response to stress, has a calming effect in adults, but actually seems to have the opposite effect in teens, increasing stress. It’s one reason why teens are prone to anxiety & post-traumatic stress disorder. It’s also a good reason, Jensen says, why parents & schools should be sensitive to the problem of bullying.
 
Along with new wiring, insulation & hormones, teen brains are highly sensitive to the release of dopamine, which plays on the areas of the brain that govern pleasure & helps explain why teens seem to take so many risks.
 
It’s not that they don’t know any better. In fact, reasoning abilities are largely developed by the age of 15 & studies have shown that teens are as accurate as adults when it comes to understanding if an activity is dangerous. Their brains are just more motivated by the rewards of taking a risk than deterred by its dangers. So even if they know something might be bad—speeding, drinking too much, trying new drugs—they get more pleasure from taking the risks anyway.
 
Central to our understanding of how teens learn is “pruning”—a period when the brain begins to shed some of the grey-matter cells built up in childhood to make room for the growth of white matter. A long period of grey-matter growth in childhood, followed by vigorous pruning in adolescence, has been linked to higher intelligence, Jensen says.
 
It’s for this reason that Jay Giedd, an expert in child & adolescent brain imaging at the U.S. National Institute of Mental Health, describes the teen years as a special period of “use it or lose it” for the brain. Brain cells grown in childhood that continue to get used in adolescence form new connections, while those that go unused wither away. It’s also another reason why parents should be anxious about what happens during the teen years—adolescence now appears to be a period that can make or break a child’s intelligence.
 
A significant consequence of pruning is that IQ, once thought to be fixed for life after childhood, can in fact change dramatically during the teen years.
 
Learning is a process of repeatedly exposing the brain to something that stimulates the production of dopamine, which strengthens connections in the brain’s reward centre & helps form new memories. Addiction, therefore, is simply a form of “overlearning” by the brain, Jensen says. That process can be controlled by the prefrontal cortex, but since teens are so primed for learning & have less of an ability to access the prefrontal cortex, they’re also more susceptible to addictions.
 
In an era marked by the ideological tug-of-war over how best to raise our teenagers, what’s a parent to do with this new science of the teenage brain? More rules—an approach exemplified by Yale professor Amy Chua’s 2011 Battle Hymn of the Tiger Mother? Or in intervening too much, do parents risk raising teens whose brains never learn how to become an adult—an approach typified by the backlash against “helicopter parenting” & movements like “slow parenting” & “free-range kids.”

In Teenage Brain, Jensen puts herself squarely in the camp of the highly involved parent. She encourages parents to proof-read their teen’s homework, help them make lists to prioritize their assignments, watch them as they do schoolwork to see if they’re getting distracted & to not be afraid to “sound like a broken record” in reminding teens over & over again about the dangers that could befall them.
 
She encourages parents to “be your teen’s frontal lobes” & to “try to think for your teenage sons & daughters until their own brains are ready to take over the job.”

Jensen argues that it’s a parent’s job to protect their teens from their own often short-sighted behaviour, while allowing them enough room for “safe failures.”

In the quagmire of parental advice, it’s no surprise that the counterargument to the neuroscience approach to parenting is robust, & passionate. Psychologist Robert Epstein, author of The Case Against Adolescence: Rediscovering the Adult in Every Teen, believes that adolescent rebellion has little to do with brain development & lots to do with how society treats teenagers. He argues scientists have it backward: teens don’t act out because they have immature brains struggling to navigate an adult world, but because they have adult brains railing against a society that treats them like children.
 
Other research is challenging the notion that teens have a less mature & less connected prefrontal cortex & are therefore inherently more impulsive than adults.
 
At Temple University, Steinberg has used a car-racing video game to show that when teens are alone they perform as well as adults on tasks involving a tradeoff of risk & reward. But when other teens are in the room watching, adolescents tend to make far riskier decisions. Adults show no difference if other adults watch them, suggesting that teen risk-taking is likely social.
 
BJ Casey, director of the Sackler Institute for Developmental Psychobiology at Cornell University, found that teens could be less impulsive if they were offered rewards. The greater the reward, the longer teens took to make a decision, suggesting that parents trying to control a hot-headed teen might want to offer rewards for good decisions rather than punishing bad ones.

“You look at the high school dropout rates & the people that fall off the curve not because of academic reasons, but because of peer pressure or drugs,” Jensen says. “It’s so sad because this is a time where you can actually make up for your innate weaknesses. We could get so much more out of our teenagers—& who they become later in life, in many cases—if we took a different approach to this window of time.”