Scientists Highlight Link Between Stress and Appetite

Researchers in the Hotchkiss Brain Institute (HBI) at the University of Calgary's Faculty of Medicine have uncovered a mechanism by which stress increases food drive in rats. This new discovery, published online this week in the journal Neuron, could provide important insight into why stress is thought to be one of the underlying contributors to obesity.

Normally, the brain produces neurotransmitters (chemicals responsible for how cells communicate in the brain) called endocannabinoids that send signals to control appetite. In this study, the researchers found that when food is not present, a stress response occurs that temporarily causes a functional re-wiring in the brain. This re-wiring may impair the endocannabinoids' ability to regulate food intake and could contribute to enhanced food drive.

The researchers also discovered that when they blocked the effects of stress hormones in the brain, the absence of food caused no change in the neural circuitry.

Researchers Jaideep Bains, Ph.D. and Quentin Pittman, Ph.D., looked specifically at nerve cells (neurons) in the region of the brain called the hypothalamus. This structure is known to have an important role in the control of appetite and metabolism and has been identified as the primary region responsible for the brain's response to stress.

Bains explains, "These findings could help explain how the cellular communication in our brains may be overridden in the absence of food. Interestingly, these changes are driven not necessarily by the lack of nutrients, but rather by the stress induced by the lack of food."

If similar changes occur in the human brain, these findings might have several implications for human health.
"For example, if we elect to pass over a meal, the brain appears to simply increase the drive in pathways leading to increased appetite," explains Pittman. "Furthermore, the fact that the lack of food causes activation of the stress response might help explain the relationship between stress and obesity."
These results lay the foundation for future studies to investigate the use of therapies that affect these systems in order to manipulate food intake. They also open the door to studies looking at whether or not the stress brought about by lack of food affects other systems where endocannabinoids are known to play a role.
"One thing we can say for sure, is that this research highlights the importance of food availability to our nervous system. The absence of food clearly brings about dramatic changes in the way our neurons communicate with each other," says Pittman.

This work was conducted jointly in the labs of Bains and Pittman and the experiments were carried out by Karen Crosby and Wataru Inoue, Ph.D. The research is supported by operating grants from the Canadian Institutes of Health Research (CIHR) and Alberta Innovates- Health Solutions (AI-HS).

Vía: Sciencedaily

7 Things McDonald’s Knows About Your Brain

When McDonald's began advertising its $1 menu featuring the Big N' Tasty burger, some franchise owners were forced to sell them at a net loss; the popular item cost $1.07 to make.  How could they afford to do this?  Because McDonald's already knew you were going to buy fries and a Coke—products with big profit margins.  It costs pennies to fill up a large drink, but you're charged more than a buck  for it.  This is a great deal for them and not such a great deal for us, but we can't help ourselves, because sugar lights up our brain's reward pathway.  Many recent neuroscience   discoveries about food's effects on our brains and how we make decisions about food are actually gold-standard trade secrets from super chains such as McDonald's. With billions and billions served, they must be on to something.

1.  Addictive properties of sugar
Nearly everything on McDonald's menu contains some sugar, from the drinks to the ketchup to the hamburger buns and fries.  McDonald's knows that most people are going to shell out an extra dollar for a soft drink because sugar is addictive.  Just as you can develop a physiological and psychological dependence on cocaine, you can become dependent on sugar.
Recent experiments have shown that sugar offers the hallmarks of addiction: bingeing, withdrawal and craving.   Researchers kept rats from eating for 12 hours, then gave them unlimited access to food and sugar water for a brief period, and then took the food and sugar away again.  They repeated this schedule for a few weeks.  The rats formed a cycle of bingeing when given access to sugar, and over time they increased their intake to twice the amount from when they started.  When the researchers stopped offering sugar or gave the rats an opioid blocker, which prevents the high by blocking some of the pleasurable effects in the brain, the rats showed signs of withdrawal, such as teeth-chattering and body tremors.
McDonald's recently added new menu items, including McCafe fruit smoothies, which pack in more sugar per serving than Coca-Cola.  With that much sugar, McDonald's slogan is probably right: we're lovin' it.

2.  The push of convenience
The fact that you can go to almost any city in the country and find a McDonald's within five minutes of driving contributes to the likelihood of compulsive eating.  Similarly, recent epidemics of addiction to cocaine and heroin have accompanied increased availability and affordability of these drugs.
Part of the reason that convenience sways us so much is that we have a limited amount of impulse control.  Some of us are better at resisting temptation, while some are more likely to give in.  Dopamine activity in your nucleus accumbens, the brain's reward center, can disrupt your brain's decision making ability by interfering with your prefrontal cortex, the brain's impulse control region.
Dopamine has five unique types of receptors, numbered 1-5, but dopamine2 (D2) receptors seem to be most important for compulsive eating.  Imaging studies show that for obese participants, fewer D2 receptors correspond to higher body-mass index.  With fewer D2 receptors, they're more likely to eat compulsively; it becomes even harder to resist super-sizing their meal.

3.  The brain's economy and the Value Meal 
Low prices minimize the pain associated with parting with your hard-earned money.  Decisions become difficult when two opposing forces try to sway you, in this case, spending money versus eating.  The brain weights the costs and benefits of a decision in a region called the orbitofrontal cortex.  Brain-imaging has shown that losing money can cause your brain to experience the same pattern of activity as when you stub your toe.  Losing money hurts.  Yet McDonald's manages to sidestep this problem by pricing a sandwich cheaper than the Sunday newspaper (which helps make up for the pain of your $40 filet mignon the night before).  At McDonald's, you get the rewarding meal without the pain of losing money.  They make the decision easy for your brain.

4.  Our brains prefer high-calorie foods
As suggested by Jonah Lehrer in "The Frontal Cortex," our brains evolved during a time when food was scarce, so we became adept at choosing foods that packed calories.
In one recent experiment, scientists used genetically engineered mice that were missing sugar receptors and therefore unable to detect sweetness in food.  The researchers then gave the mice free access to two water dispensers, one with sugar water and one with regular water.  Initially, the mice showed no preference; sugar water tasted just like regular water.   However, after several hours, the mice shifted to drinking almost exclusively from the sugar water dispenser.  To ensure that the mice preferred the calories, but could not detect the taste, the researchers offered them water sweetened with sucralose (e.g. Splenda).  The mice didn't take it.
When the scientists analyzed the mice brains, they found that the mice released dopamine in response to sugar water, even though they couldn't taste it, but not in response to regular water or sucralose.  Our brains can tell the difference between high calorie foods and diet foods even if they taste the same.

5.  Addictive properties of speed
Drugs have a hierarchy of addictive potential based on the speed that they reach your brain.   Pills have to be swallowed, broken down in the stomach, pushed into the digestive tract and then absorbed into the blood stream before they can reach your brain.  The reward you experience comes relatively long after you take the drug.  Heroin skips the lag time; injecting it directly into your bloodstream sends it to your brain within seconds.  The closer you can pair a stimulus with a reward, the stronger the association will be.
Similarly, fast food provides a quick fix for hunger.  You don't even have to get out of your car to pick up a Big Mac.  You place your order at the drive-thru and within two minutes you can take the first bite as you drive home.  You can hardly get a pan hot enough to fry in that time.  The sooner you have the burger in hand, the sooner it can trigger the release of the cocktail of rewarding chemicals in your brain.

6.  Brains like branding
Just as Pavlov was able to get a dog to salivate at the sound of a bell, McDonald's gets your juices flowing anytime you hear their jingle.  Pavlov showed that if he rang a bell before giving food to a dog, eventually the bell itself would whet its appetite.
Across the nation, McDonald's provides a consistent experience every time you enter its doors.  The employees recite a scripted greeting, the menu looks the same, and the same images and logos are posted on the walls.   The more consistent the experience, the more strongly your brain associates the Golden Arches with the meal that follows.
The brain's reward chemical is dopamine, a molecule that's released when you experience something you enjoy.  However, one of the brilliant aspects of the brain is its ability to learn and make predictions about the world based on past experiences.  When the brain learns that a certain cue is associated with a reward, dopamine neurons learn to fire whenever the cue appears, even before the reward is given.   Dopamine does more than simply reward you; it also motivates you to seek the pleasure again.  As soon as you see the cue, your brain begins to anticipate the reward.  The anticipation is part of the pleasure.  Would you like fries with that?

7.  McNuggets stoke your memory
In a recent study, researchers gave children chicken nuggets in an unmarked container or in McNuggets packaging.  Not surprisingly, kids preferred the ones that resembled a Happy Meal.  Neuroscience research has shown that a big part of the pleasure of eating stems from memories tied to the food, not taste alone.

In a brain-imaging study of the Pepsi Challenge, Read Montague at Baylor College of Medicine first gave participants a blind taste test of Coca-Cola and Pepsi while in an MRI scanner.  The subjects preferred Coca-Cola and Pepsi equally, and both of the sodas caused brain activity in the ventromedial prefrontal cortex, a region involved in pleasure and reward.  However, when the subjects were told they were drinking Coke, they shifted their preference.   Now, 75 percent preferred Coke. What's more, their brain activity changed.  The hippocampus, the brain region crucial to memory formation, lit up with activity, suggesting that drinking Coca-Cola, rather than a generic soft-drink, stirs up your memories of Coca-Cola.
Similarly, eating a McNugget not only sates your appetite for chicken (and the glue that holds the McNugget together), it also reminds you of your childhood, the cool Transformers toy you got in your Happy Meal, and the first time you were big enough to order the 10-piece instead of the 4-piece.


What can we do?
Like the call of the Sirens, we all know that fast food is bad for us, but who among us can resist?  One idea is to learn from Odysseus and how he escaped the Sirens.  He had the crew of his ship tie him to the mast before they sailed past the Sirens so that he couldn't change course and steer toward them.  As he drew near, their calls lured him.  He decided to give up and follow their song, even if it meant death, and he begged his crew to untie him.  The crew expected his weakness, refused his request and instead bound him tighter.  He lived thanks to their help.
If you want to break your habit, try making a deal with a friend.  They don't need to tie you to your chair, but they can establish consequences for your behavior.  For example, if you break down, then they donate money to an organization you despise.  That way, you're held accountable not just to yourself, but to your values and community.
Or, you could just give into the Sirens.  Doesn't that sound nice?

Via: PsychologyToday

Cambios cerebrales positivos luego de meditación de cuerpo y mente

Aumento en la conectividad cerebral

Luego de once horas de entrenamiento, las mejoras en conexiones de áreas que regulan la emoción se hacen claras, muestran escáneres.


Cambios cerebrales positivos tienen lugar luego de apenas once horas de práctica de una forma de meditación, según sugieren los resultados de un estudio reciente.
En el estudio participaron 45 estudiantes de la Universidad de Oregón que se seleccionaron al azar para estar en un grupo de estudio que hacía capacitación integradora de cuerpo y mente (CICM), o un grupo de control que hizo capacitación en relajación. La CICM se adaptó de la medicina tradicional china en los 90.
Una comparación de escáneres realizados en los cerebros de los estudiantes antes y después de la capacitación mostró que los del grupo de CICM tenían una mayor conectividad cerebral. Los cambios fueron más contundentes en las conexiones que tenían que ver con la corteza cingulada anterior, un área que tiene que ver con la regulación de las emociones y la conducta, encontraron Yi-Yuan Tang, de la Universidad de Tecnología Dalian en China, el psicólogo de la Universidad de Oregón Michael I. Posner y colegas.
El aumento en la conectividad cerebral comenzó tras seis horas de CICM, y se hizo más claro tras once horas de práctica, según un informe publicado en la edición en línea del 16 al 21 de agosto de la revista Proceedings of the National Academy of Sciences.

Los cambios inducidos por la meditación podrían deberse a una reorganización de los tractos de materia blanca, o a un aumento en la mielina que rodea a las conexiones cerebrales, sugirieron los autores del estudio.
"La importancia de nuestro hallazgo se relaciona con la capacidad de realizar cambios estructurales en una red cerebral relacionada con la autorregulación. La vía que experimenta el cambio más grande debido a la CICM es una que anteriormente se ha mostrado se relaciona con las diferencias individuales en la capacidad de la persona para regular el conflicto", aseguró Posner en un comunicado de prensa.







Vía: Intramed

Intestinal Protein May Have Role in ADHD, Other Neurological Disorders

A biochemical pathway long associated with diarrhea and intestinal function may provide a new therapeutic target for treating ADHD (Attention Deficit Hyperactivity Disorder) other neuropsychiatric disorders, according to a team of scientists from China and the United States reporting Aug. 11 in Science.

Scientists have for the last quarter century studied the intestinal membrane receptor protein, guanylyl cyclase-C (GC-C) for its role in diarrheal disease and other intestinal functions, according to Mitchell Cohen, M.D., U.S. author on the study and director of Gastroenterology, Hepatology and Nutrition at Cincinnati Children's Hospital Medical Center. In fact, it had been thought that GC-C was found primarily in the intestine.
In the current study, scientists in China who collaborated with Dr. Cohen discovered that the receptor is also expressed in critical areas of the brain. The senior author on the study is Dr. Minmin Luo, a researcher at the National Institute of Biological Sciences and Tsinghua University in Beijing.
Using a mouse model developed in Dr. Ralph Giannella's laboratory at the University of Cincinnati, in which the GC-C receptor is deleted, or knocked out, the researchers found the mice exhibit hyperactivity and attention deficits. It is the first time that GC-C has been linked to neuropsychiatric disorder, according to the researchers.
"We show that the neurons selectively express GC-C and that its activation amplifies the excitatory responses mediated by other receptors on dopamine neurons in the midbrain," said Dr. Luo. "Working through a protein kinase called PKG, GC-C activity increases brain dopamine levels and thus regulate mouse attention and activity level."
When the researchers treated the GC-C knockout mice with amphetamine-based ADHD medication and a PKG activator, it reversed their hyperactive, inattentive behavior.
"The results indicate important behavioral and physiological functions for the GC-C/PKG signaling pathway in the brain," said Dr. Luo. "The data also suggest new therapeutic targets for neuropsychiatric disorders related to malfunctions of midbrain dopamine receptors."
One of the most prevalent human behavioral disorders, ADHD has been linked to imbalances in the dopamine system. The researchers noted in the study that its findings -- mice exhibiting reduced dopamine levels and related behavioral problems -- are consistent with the biochemical characteristics of human ADHD.
"This could make the GC-C knockout mouse a good research model for ADHD and other behavioral disorders," said Dr. Cohen. "Efforts to develop activators or inhibitors of the GC-C/PKG signaling pathway may lead to novel treatments for other disorders, such schizophrenia, Parkinson's disease and addiction."
The first author on the study is Rong Gong, who is in the joint graduate program of Peking Union Medical College and the National Institute of Biological Sciences in Beijing. Other institutions collaborating on the study include: the College of Life Sciences, Beijing Normal University and the Wuhan Institute of Physics and Mathematics at the China Academy of Sciences in Wuhan, China.

Via: Scienedaily

Narcissists Look Like Good Leaders, but They Aren't

Narcissists rise to the top. That's because other people think their qualities -- confidence, dominance, authority, and self-esteem -- make them good leaders.

Is that true? "Our research shows that the opposite seems to be true," says Barbora Nevicka, a PhD candidate in organizational psychology, describing a new study she undertook with University of Amsterdam colleagues Femke Ten Velden, Annebel De Hoogh, and Annelies Van Vianen. The study found that the narcissists' preoccupation with their own brilliance inhibits a crucial element of successful group decision-making and performance: the free and creative exchange of information and ideas. The findings will be published in an upcoming issue of Psychological Science, a journal of the Association for Psychological Science.

The study recruited 150 participants and divided them into groups of three. One person was randomly assigned to be the group's leader; all were told they could contribute advice, but that the leader was responsible for making the decision. Then they undertook a group task: choosing a job candidate. Of 45 items of information about the candidate, some were given to all three, and some to only one of the participants.
The experiment was designed so that using only the information all three were privy to, the group would opt for a lesser candidate. Sharing all the information, including what each possessed exclusively, would lead to the best choice. Afterwards, the participants completed questionnaires. The leaders' questions measured narcissism; the others assessed the leaders' authority and effectiveness. All checked off the items among the 45 that they knew -- indicating how much the group had shared -- and rated how well they'd exchanged information. Experimenters tallied the number of shared items, noted the objective quality of the decision, and analyzed these data in relation to the leader's narcissism.

As expected, the group members rated the most narcissistic leaders as most effective. But they were wrong. In fact, the groups led by the greatest egotists chose the worse candidate for the job. Says Nevicka, "The narcissistic leaders had a very negative effect on their performance. They inhibited the communication because of self-centeredness and authoritarianism."

Narcissism can sometimes be useful in a leader, says Nevicka. In a crisis, for instance, people feel that a strong, dominant person will take control and do the right thing, "and that may reduce uncertainty and diminish stress."

But in the everyday life of an organization, "communication -- sharing of information, perspectives, and knowledge -- is essential to making good decisions. In brainstorming groups, project teams, government committees, each person brings something new. That's the benefit of teams. That's what creates a good outcome." Good leaders facilitate communication by asking questions and summarizing the conversation -- something narcissists are too self-involved to do.

Nevicka says the research has implications beyond the workplace -- for instance, in politics. "Narcissists are very convincing. They do tend to be picked as leaders. There's the danger: that people can be so wrong based on how others project themselves. You have to ask: Are the competencies they project valid, or are they merely in the eyes of the beholder?"

Think Healthy, Eat Healthy: Scientists Show Link Between Attention and Self-Control

You're trying to decide what to eat for dinner. Should it be the chicken and broccoli? The super-sized fast-food burger? Skip it entirely and just get some Rocky Road?

Making that choice, it turns out, is a complex neurological exercise. But, according to researchers from the California Institute of Technology (Caltech), it's one that can be influenced by a simple shifting of attention toward the healthy side of life. And that shift may provide strategies to help us all make healthier choices -- not just in terms of the foods we eat, but in other areas, like whether or not we pick up a cigarette.

Their research is described in a paper published in the July 27 issue of the Journal of Neuroscience.

When you decide what to eat, not only does your brain need to figure out how it feels about a food's taste versus its health benefits versus its size or even its packaging, but it needs to decide the importance of each of those attributes relative to the others. And it needs to do all of this more-or-less instantaneously.

Antonio Rangel, professor of economics and neuroscience at Caltech, has been studying this value-deriving and decision-making process for years now. Along with Todd Hare -- a former postdoc at Caltech who is now an assistant professor of neuroeconomics at the University of Zurich in Switzerland -- he published a paper in Science in 2009 describing differences in the brains of people who are better at exercising self-control than others. What they found was that while everyone uses the same area of the brain -- the ventral medial prefrontal cortex, or vmPFC -- to make value-laden decisions like what to munch on, there's a second brain area -- the dorsolateral prefrontal cortex, or dlPFC -- that seems to come to life when a person is using self-control during the decision-making process.

In other words, when the dlPFC is active, it allows the vmPFC to take into account health benefits as well as taste when it assigns a value to a particular food.

The new study goes a step further, showing that there seem to be ways to help kickstart the dlPFC through the use of what Hare calls "external cues" that allow us to exhibit more self-control than we might have otherwise.

The researchers came to their conclusions based on data from a brain-imaging experiment conducted with 33 adult volunteers, none of whom were following a specific diet or trying to lose weight for any reason. Each of the volunteers was shown 180 different food items -- from chips and candy bars to apples and broccoli -- through a set of video goggles while in a functional magnetic resonance imaging (fMRI) machine.

The hungry subjects -- they were asked to fast for at least three hours prior to the experiment -- were given up to three seconds to respond to each picture with a decision about whether or not they'd want to eat the food shown after the experiment was over. They could either give the food a "strong no," a "no," a "yes," or a "strong yes." Once all of the images had been flipped through, a single food image was chosen at random; if the volunteer had said "yes" or "strong yes" to the idea of eating that food, he or she was served that item.

"Because only one random trial was selected to 'count,'" says Rangel, "the optimal strategy for subjects is to treat each decision as if it were the only one."

Simple, right? But here's the catch: before every 10 food choices, an instruction would come on the screen for five seconds telling the subjects either to "consider the healthiness," "consider the tastiness," or "make decisions naturally." This meant that of the 180 decisions, the subjects made 60 in each of the three "instruction conditions."

What this was meant to do, Rangel explains, is shift the subject's attention during the experiment and, potentially, shift the way in which they made decisions.

Afterward -- outside the scanner -- the subjects were asked to rate the same foods on both a tastiness scale (very untasty, untasty, tasty, very tasty) and a healthiness scale (very unhealthy, unhealthy, healthy, very healthy). That way, the researchers were able to associate the choices the subjects made during the brain scan with their stated perceptions of those foods' attributes -- showing that a subject who chose broccoli during the "consider the healthiness" portion of the test might think of it nonetheless as untasty.

The researchers then classified the foods for each subject based on that subject's ratings: unhealthy-untasty, healthy-untasty, unhealthy-tasty, and healthy-tasty. Unsurprisingly, people chose healthy-tasty foods no matter where their attention had been directed.

Things got interesting when the researchers looked at the other three categories, however. Among their findings:

• When thinking about healthiness, subjects were less likely to eat unhealthy foods, whether or not they deemed them to be tasty, and more likely to eat healthy-untasty foods.
• Being asked to think about healthiness led subjects to say "no" to foods more often than they did when asked to make decisions naturally.
• There were no real differences between the choices made during the "consider the tastiness" and "make decisions naturally" portions of the experiment.

When the researchers turned to the fMRI results, they found that the vmPFC was, as predicted, "more responsive to the healthiness of food in the presence of health cues," says Rangel. And, as they'd seen previously, the robustness of that response was due to the influence of the dlPFC -- that bastion of self-control -- which was much quieter when the study's subjects were thinking about taste or their own personal choice than when they were asked to throw healthiness into the equation.

"This increased influence of the health signals on the vmPFC results in an overall value for the food that is based more on its health properties than is the case when the subject's attention is not focused on healthiness," says Hare.

These results are most likely not limited just to choices about food, Hare says. "Our findings are also relevant to the current changes to cigarette warnings many governments have started to make," he notes. "These changes include adding graphical images of the health risks of smoking. It remains to be seen whether these images will be more effective in drawing attention to the unhealthiness of smoking than the text warnings. If the graphical warnings do increase attention to health, then our results suggest that they could decrease the desire to smoke."

Jonathan Malmaud, a former research assistant at Caltech who is now a graduate student at MIT, was also an author on theJournal of Neuroscience paper, "Focusing attention on the health aspects of foods changes value signals in the vmPFC and improves dietary choice." The scientists' work was funded by a grant from the National Science Foundation

Frequent Tanning Bed Users Exhibit Brain Changes and Behavior Similar to Addicts, Study Finds

People who frequently use tanning beds may be spurred by an addictive neurological reward-and-reinforcement trigger, researchers at UT Southwestern Medical Center have found in a pilot study.

This could explain why some people continue to use tanning beds despite the increased risk of developing melanoma, the most lethal form of skin cancer. The brain activity and corresponding blood flow tracked by UT Southwestern scientists involved in the study is similar to that seen in people addicted to drugs and alcohol.

"Using tanning beds has rewarding effects in the brain so people may feel compelled to persist in the behavior even though it's bad for them," said Dr. Bryon Adinoff, professor of psychiatry and senior author of the study available online and in a future print edition ofAddiction Biology. "The implication is, 'If it's rewarding, then could it also be addictive?' It's an important question in the field."

About 120,000 new cases of melanoma are diagnosed in the U.S. each year, according to the Skin Cancer Foundation. People younger than 30 who use a tanning bed 10 times a year have eight times the risk of developing malignant melanoma. While public knowledge of these dangers has grown, so has the regular use of tanning beds.

In this study, participants used tanning beds on two separate occasions: one time they were exposed to ultraviolet radiation and another time special filters blocked exposure to ultraviolet radiation. Participants did not know on which session they received the real or the filtered ultraviolet exposure. At each visit, participants were asked before and after each session how much they felt like tanning. Participants were also administered a compound that allowed scientists to measure brain blood flow while they were tanning.

Dr. Adinoff, who also is a staff physician at the Veterans Affairs North Texas Health Care System, said the next step is to create technology to further study brain changes among frequent tanners.

Other UT Southwestern researchers involved in the study were Dr. Heidi Jacobe, assistant professor of dermatology; Dr. Michael Devous, professor of radiology; and Thomas Harris, senior research scientist. Former dermatology resident Dr. Cynthia Harrington served as lead author.

The study was funded by the Department of Dermatology at UT Southwestern. Dr. Steven Feldman of Wake Forest University donated the ultraviolet radiation filters used in the tanning bed, and GE Healthcare donated the radioligand, the compound that traced the brain changes

Drinking Energy Beverages Mixed with Alcohol May Be Riskier Than Drinking Alcohol Alone

• A new laboratory study compares the effects of alcohol alone versus alcohol mixed with an energy drink on a cognitive task, as well as participants’ reports of feelings of intoxication.
• Results show that energy drinks can enhance the feeling of stimulation that occurs when drinking alcohol.
• However, energy drinks did not alter the level of behavioral impairment when drinking alcohol, particularly for impaired impulse control.
• The combination of impaired impulse control and enhanced stimulation may make energy drinks combined with alcohol riskier than alcohol alone.

Energy drinks mixed with alcohol, such as Red Bull™ and vodka, have become trendy. While this consumption has been implicated in risky drinking practices and associated accidents and injuries, there is little laboratory research on how the effects of this combination differ from those of drinking alcohol alone. A recent laboratory study, comparing measures of intoxication due to alcohol alone versus alcohol/energy drink, has found that the combination of the energy drink enhanced feelings of stimulation in participants. However, the energy drink did not change the level of impairment for impulsive behavior. These findings suggest that energy drinks combined with alcohol may increase the risks associated with drinking.
Results will be published in the July 2011 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
“Young people are now drinking alcohol in different ways than they have in the past,” said Cecile A. Marczinski, assistant professor of psychology at Northern Kentucky University and first author of the study. “Classic mixed drinks such as rum and coke have been replaced with mixed drinks that use energy drinks instead, such as yagerbombs and Red Bull™ and vodka.”
“We have sales data showing that energy drinks have gained in popularity, and we know anecdotally that this practice is popular, but we have little data on objective and subjective responses that support growing concern about the safety of mixing energy drinks with alcohol,” said Amelia M. Arria, director of the Center on Young Adult Health and Development at the University of Maryland School of Public Health.
Marczinski concurred. “While consuming energy drinks with alcohol is thought of as a risky drinking practice, the laboratory evidence demonstrating this is quite limited,” she said. “In fact, most of the evidence that consuming alcohol/energy drinks is risky comes from epidemiological studies that have reported an increased risk of accidents and injuries associated with their use. However, those studies do not address the key confound that risky drinkers, who are prone to drinking heavily anyways, are just attracted to these drinks since they are trendy. Our study was designed to demonstrate that alcohol/energy drinks are pharmacologically distinct from alcohol alone and are adding to the risks of drinking.”
Marczinski and her colleagues randomly assigned 56 college student participants (28 men, 28 women), between the ages of 21 and 33, to one of four groups that received four different doses: 0.65 g/kg alcohol, 3.57 ml/kg energy drink, energy drink/alcohol, or a placebo beverage. The participants’ behavior was measured on a task that measures how quickly one can execute and suppress actions following the dose. Participants also rated how they felt, including feelings of stimulation, sedation, impairment, and levels of intoxication.
“We found that an energy drink alters the reaction to alcohol that a drinker experiences when compared to a drinker that consumed alcohol alone,” said Marczinski. “A consumer of alcohol, with or without the energy drink, acts impulsively compared to when they had not consumed alcohol. However, the consumer of the alcohol/energy drink felt more stimulated compared to an alcohol-alone consumer. Therefore, consumption of an energy drink combined with alcohol sets up a risky scenario for the drinker due to this enhanced feeling of stimulation and high impulsivity levels.”
“To reiterate,” said Arria, “the investigators found that the presence of an energy drink did not change the level of impairment associated with alcohol consumption.” It did, however, change the perception of impairment.
“The findings from this study provide concrete laboratory evidence that the mixture of energy drinks with alcohol is riskier than alcohol alone,” said Marczinski. “College students need to be aware of the risks of these beverages. Moreover, clinicians who are working with risky drinkers will need to try and steer their clients away from these beverages.”

Deep Brain Stimulation Effects May Last for 10 Years in Patients With Parkinson's Disease

One decade after receiving implants that stimulate areas of their brains, patients with Parkinson's disease (PD) appear to sustain improvement in motor function, although part of the initial benefit wore off mainly because of progressive loss of benefit in other functions, according to a report published Online First by Archives of Neurology, one of the JAMA/Archives journals.

According to background information in the article, several previous clinical studies have shown deep brain stimulation of the subthalamic nucleus (STN-DBS) for PD to be effective and safe. Studies have shown that the technique, which stimulates a part of the brain involved in motor function, may have advantages compared with other medical treatments in terms of controlling motor complications and improving quality of life. "The motor improvement induced by STN stimulation has been reported to be sustained for up to five to eight years after surgery, although part of the initial benefit progressively deteriorates, mainly because of worsening axial signs," write the authors. "To date, studies with postoperative follow-up for longer than eight years are lacking."
Anna Castrioto, M.D., from the Università degli Studi di Perugia, Perugia, Italy, and colleagues conducted a study of 18 patients with advanced PD who had received DBS implants for PD between 1996 and 2000. Motor assessments were conducted before implantation and at one, five and 10 years. All motor assessments were videotaped. Patients were assessed without medication, without stimulation, without either, and with both. At each assessment, the researchers recorded every patient's medications and dosages.

At 10 years, the combination of medication and STN-DBS was associated with significantly better motor, resting and action tremor, bradykinesia (slowed movement) and rigidity scores. Compared with baseline, reductions were also seen in the scores in the medication and no medication conditions, the dyskinesia (difficulty controlling movement) and motor fluctuation scores and the levadopa-equivalent daily dose. However, axial signs (such as posture, gait and balance) showed the most progressive decline in stimulation and medication response.
"Our findings further support the long-term response to STN stimulation in patients with advanced PD, showing a prolonged motor improvement up to 10 years," conclude the authors.

How to become a memory Master

We all have days at work we'd rather forget, but don't seek solace in the glare of the TV screen or the bottom of a bottle. MH's precisely calibrated evening plan will tune up your powers of recollection today to optimise your performance for tomorrow.

7pm – HIIT the gym

The area of your brain responsible for memory formation is the hippocampus – and the bigger yours the better. Researchers from the University of Illinois and the University of Pittsburgh recently discovered a strong correlation between physical fitness and hippocampus size. "If you want to keep your memory and the rest of your mental skills in shape, you need to feed your brain through regular exercise," says Tony Buzan, inventor of Mind Mapping and author of over 100 books on the brain.

Memorable move High intensity interval training and Tabata sessions are the most time-efficient ways to supercharge your cardio training. A recent Journal of Physiology study found doing 10 one-minute sprints on a stationary bike with one minute rest in between, three times a week, boosts health and fitness more effectively than 10 hours cycling continuously at a moderate pace.

7.45pm – Refuel with blueberries

Blueberries are show-offs. As well as being loaded with cholesterol-quashing resveratrol and containing more high-quality antioxidants than virtually any other foodstuff, they'll also upgrade your grey matter. A recent study published in The Journal of Agricultural and Food Chemistry found volunteers who drank two cups of blueberry juice a day for six weeks boosted their performance in memory and learning tests by 30%.

Memorable move Down this Berry Immune Booster shake from England rugby nutritionist Matt Lovell after your workout. Simply throw the ingredients in your blender – and blitz.

Ingredients

1 handful dried blueberries
1 apple, chopped
1 scoop strawberry-flavoured whey protein powder
1 dessert spoon no-added-sugar blueberry jam
1 handful prunes
1 dessert spoon low-fat cottage cheese
1 dessert spoon natural yoghurt
150ml water

10pm – Turn in early

Early to bed and early to rise makes a man healthy, wealthy and wise. A recent study published in the journal Current Directions in Psychological Science found that sleep reorganises and reconfigures memories, aiding creativity and streamlining cognitive function. "After a good night's sleep there's increased efficiency of the processing that people use to retrieve information," says Dr Elizabeth Kensinger, director of Boston College's Cognitive and Affective Neuroscience Laboratory. Post-slumber, fewer brain regions are required to recall memories – and neurons are far more densely interconnected. This explains why mornings are the most fertile time for creativity.

Memorable move Kensinger recommends a minimum of seven hours kip a night. If you're struggling to drop off, try these meals designed to promote sleep, optimise your environment to encourage quality shuteye, and follow our 60-minute countdown to an instant knockout.

Via:
Men´s Health

Sobre mirar TV y la vulnerabilidad de la niñez

El presente documento ha sido preparado por Sara Vaquero Tostado, recopilando la información de diferentes fuentes, para la realización del Taller “Alternativas a la televisión y los videojuegos” de Escuela de Familia organizado por la Fundación Rudolf Steiner en marzo del 2.011. Esto que reproducimos aquí es sólo un resumen.

Creo que todos sabemos que ver la televisión no es muy saludable y menos para los más pequeños. Con mi exposición no pretendo convencer a nadie para que deje de ver la televisión. Lo único que quiero es informar de sus efectos y de los riesgos que corremos a la hora de dejar un libre acceso a ella a nuestros hijos e hijas. Me gustaría que recordéis la última vez que visteis la televisión, qué posición tenía vuestro cuerpo, como estabais sentados en el sofá al principio y como terminasteis. Si fue una decisión
consciente la que os llevó a ver la televisión, porque os apetecía ver un determinado programa o una película en concreto o si por el contrario la encendisteis para ver qué ponían, o por si echaban algo interesante… ¿Cuánto tiempo estuvisteis viendo la televisión? ¿Más del que teníais pensando en un principio o cuando terminó lo que queríais ver la apagasteis?

Los niños, vulnerables
Ahora, os propongo que observéis a vuestros hijos mientras ven la tele, o juegan con el ordenador o los videojuegos. Cómo es su postura, cómo es su mirada. Si hacéis esto podréis comprobar que su mirada es distraída, sin expresión, con la boca entreabierta y el cuerpo hundido en el sofá. Pues como veremos la televisión tiene un efecto hipnótico. Puede que alguna de las descripciones sean: “pasivos”, “zombis”, “estupefactos”,
“hipnotizados”, “sedados”, “completamente absortos pero no interesados”.
Esta observación nos puede llevar a plantearnos si es saludable esta actividad para vuestros hijos.

Riesgos físicos y psíquicos
¿Por qué resulta difícil apagar el aparato? Los medios electrónicos son fáciles de encender, pero difíciles de apagar. Las causas de esa dificultad residen tanto en el contenido como en el medio. Los niños necesitan ayuda para apagarlos porque la televisión y los medios electrónicos inhiben las funciones cerebrales implicadas en el proceso de tomar decisiones. Nuestro cerebro está formado por dos hemisferios, el hemisferio izquierdo se considera “dominante” y controla el lado derecho del cuerpo. (En los zurdos el hemisferio derecho es el dominante). El hemisferio dominante es nuestro ser activo, está en relación con la forma y actividad de nuestro exterior y se ocupa del tiempo. Mantiene nuestra conciencia de vigilia, nuestro pensamiento lineal. Es nuestro lado racional, el que alberga el centro del habla y del lenguaje o área de Broca.
El hemisferio derecho, llamado “subdominante”, está vinculado con el inconsciente en la mayor parte de las personas. Raramente se experimenta este lado en estado de vigilia. Es nuestra “otra mitad”. Es nuestro lado de la naturaleza, nuestros instintos, nuestra fuente artística y creativa, y no es necesariamente racional. En esta esfera no existe el tiempo, sólo el espacio, como en la mente del niño: da lugar a los sueños y las fantasías. Ahí existe todo como uno. Procesa la información emocionalmente, no críticamente.

HEMISFERIO IZQUIERDO                    HEMISFERIO DERECHO
Dominante                                              Subdominante
Controla el lado derecho del cuerpo      Controla el lado izquierdo del cuerpo
Consciencia                                            Inconsciente
Centrado en lo exterior                          Centrado en lo interior
Pensamiento lineal                                 Imágenes y sueños
Secuencia                                              Ciclo
Lógica                                                    Asociación
Lenguaje                                                Música
Racional                                                 Instinto
Análisis                                                  Síntesis

La actividad de la mente puede ser descrita según los esquemas de las ondas cerebrales, midiendo la cantidad de actividad eléctrica en las diferentes partes del cerebro. Los ritmos básicos son cuatro: beta, alfa, theta y delta. El beta es el de 12 a 24 ciclos por segundo (cps), y está relacionado con la palabra activa o pensamiento numérico, produciéndose cuando está haciendo planes o resolviendo un problema. El ritmo alfa, de 8 a 12 cps, es el llamado de estado de descanso, el zumbido de fondo que se produce cuando el cerebro se está recargando: no sucede nada, no está pensando. El estado theta se produce entre los 4 y 8 cps, y está relacionado con los estado visuales y de sueño, el pensamiento por medio de imágenes errantes por el espacio, a través de placeres pasados y excitaciones futuras. Si se relaja y representa una imagen en su mente producirá este ritmo. El ritmo delta es el más bajo, y se relaciona con el sueño profundo. Se produce entre 0 y 4 cps.


Encefalogramas
Hebert Krugman, observando el encefalograma de los televidentes, constató que en 30 minutos se pasaban de ondas beta (que indican un estado de alerta y atención consciente) a ondas alfa (que indican falta de atención receptiva). Krugman quedó impresionado por la velocidad a la que surgía el estado alfa. A los lectores de libros y revistas les aparecen las ondas beta, que son una señal de alerta, de atención y de la conciencia de la vigilia. Por lo que podemos decir que la TV nos hipnotiza, nos quedamos paralizados, inhibe las funciones cerebrales implicadas en el proceso de tomar decisiones. Se hizo otro experimento con 10 niños viendo su programa televisivo favorito. Se formuló previamente la hipótesis de que como los niños estaban interesados, los dibujos de las ondas cerebrales alternarían entre las ondas beta y las alfa. Sin embargo, “no lo hicieron. Los niños se hundieron en las butacas y estuvieron casi todo el rato en alfa. Esto significa que mientras estaban viendo la televisión, ni reaccionaban, ni se orientaban ni enfocaban; sencillamente estaban “alelados”. Una explicación de este fenómeno es que la televisión cierra la parte izquierda del cerebro,
Que, como he dicho, es la de la lógica, y deja el hemisferio derecho abierto a las imágenes entrantes. Como he comentado, el hemisferio izquierdo del cerebro se encarga de la lógica secuencial, las palabras, el análisis y el razonamiento. Sólo procesa un estímulo cada vez, lo que da lugar a metódicas secuencias de pensamiento. La parte izquierda del cerebro “se desconecta” cuando uno ve la televisión. El hemisferio derecho se ocupa de las imágenes, los colores, los ritmos y las emociones, y procesa la información emocionalmente, no críticamente. El cerebro izquierdo recoge el contenido de lo que alguien dice, mientras que le derecho admite el gesto no verbal, el tono de voz y la mirada.
Este conocimiento viene de principios de los años 60, cuando se descubrió que la mente de los niños se volvía catatónica frente al televisor. Tiene que ver con la forma en que el cerebro reacciona ante la luz radiante, que es la fuente de luz de la televisión y monitores de ordenador, y la luz reflejada, que es la que nos trae el resto de nuestra experiencia visual. El cerebro tiende a cerrarse en respuesta a las fuentes de luz radiante. La luz radiante es la razón por la cual pasamos de ondas beta a alfa en 30 minutos. Todos hemos visto a los niños hipnotizados cuando ven la televisión durante un periodo de tiempo.
Los anunciantes
Mientras vemos la TV, la parte derecha del cerebro, que no es crítica, puede trabajar sin ser molestada. Por eso la TV es un medio de comunicación que transmite sin el menor esfuerzo enormes cantidades de información en las que no se piensa mientras se está expuesto a ellas. Los anunciantes se dieron cuenta de que los medios electrónicos poseían la gran ventaja de proporcionarles acceso directo a las mentes de la gente.
La publicidad puede ser muy nociva para los niños porque les manipula, las imágenes y la forma de presentar los productos les hace desearlos pero ellos no saben que se los están intentando vender y los niños exigen a sus padres que se los compren. Hay que tener muy en cuenta la manipulación a la que se ven expuestos a través del marketing y del diseño. Los niños menores de 8 años son incapaces de entender los objetivos de la publicidad y tienden a aceptar las afirmaciones como ciertas. ¿Cuáles son las consecuencias para los niños? Pues las consecuencias son varias, en primer lugar los niños son más impresionables y están muy abiertos a las imágenes electrónicas y, por lo tanto, al estado de “alelamiento” al que induce el medio”.
En segundo lugar, si efectivamente los medios electrónicos inhiben el área de la toma de decisiones del cerebro, entonces los niños sencillamente son incapaces de apagar el televisor, y, en consecuencia, son los padres lo que han de apagarlo para sus hijos.
En tercer lugar, la velocidad de las imágenes y la visualización electrónica hacen que no puedan despegar los ojos de la televisión. Un estudio publicado por la revista Biologist sostiene que mirar TV puede dañar a las personas, especialmente a las niñas. Este estudio lleva la firma de Aric Sigman, miembro del Instituto de Biología de Gran Bretaña y de la Sociedad Psicológica Británica. El artículo cita un trabajo que publicó la revista Pediatrics, órgano de la Academia de Pediatría de Estados Unidos: el estudio, dirigido por Dimitri Christakis, de la Universidad de Washington, y efectuado sobre 2623 chicos, encontró que “la exposición a la televisión antes de los tres años se asocia con problemas en la atención a la edad de siete años”. Estos problemas eran “consistentes con un diagnóstico de déficit atencional”. El problema no son los contenidos, sino los estímulos que ofrece la pantalla. El chico que vea televisión antes de los tres años de edad corre más riesgo de tener problemas para prestar atención cuando, a los seis o siete años, vaya a la escuela. Esto se vincula con que la pantalla de la tele ofrece estímulos “más interesantes que los que usualmente brinda la vida real”. Además, las técnicas de edición y presentación televisivas acostumbrarían al chico a modalidades de atención muy rápidamente cambiantes, a la vez que intensas. Todo esto vendría a “corromper el sistema fisiológico de la atención”, independientemente del contenido de los programas. Otros trabajos citados en el artículo vinculan el exceso de tele en la niñez con dificultades para dormir, obesidad e incluso con un mayor riesgo de autismo. El trabajo viene a avalar las indicaciones de la Academia de Pediatría de Estados Unidos: que los menores de dos años no vean televisión en absoluto y que los chicos de cualquier edad no tengan tele en su cuarto. Según explica Sigman, “la televisión suscita la denominada ‘respuesta orientativa’, por la cual la persona responde al movimiento y a cambios repentinos en la visión o el sonido. En cuanto a la televisión, esta respuesta se verifica casi desde el nacimiento: los bebés giran sus cuellos hasta 180 grados para verla”.

Técnicas persuasivas
El artículo destaca que, cada vez más, la televisión apela a diversas técnicas como los cortes, cambios de cámara, zooms, “paneos”, sonidos repentinos y diversos recursos de edición que, al activar esa respuesta orientativa, incrementan la atención del espectador. Un estudio sobre el ritmo y la edición del popular programa Plaza Sésamo, a lo largo de 26 años, mostró que la cantidad de esos recursos se duplicó. Esas “recompensas”, esas retribuciones que ofrece la tele, tendrían un correlato fisiológico específico y medible: es un neurotrasmisor, la dopamina. “La liberación de dopamina en el cerebro y se asocia con la recompensa por prestar atención, especialmente a cosas nuevas y estimulantes.” La sobreestimulación generada por la tele incrementaría los niveles habituales de dopamina, lo cual vendría a “corromper el sistema fisiológico que recompensa la atención”, según Sigman.

La industria de la televisión intenta contrarrestar el efecto hipnótico que tiene mediante la introducción de lo que se conoce como “efectos sorpresa o sobresalto” en la programación de los niños. Un efecto de sobresalto es cualquier cosa que desencadene en el cerebro el pensamiento de que podría haber una situación de emergencia y lo ponga alerta para prestar atención a la fuente de la perturbación. La televisión logra esto con los cambios repentinos y dramáticos de la intensidad de la luz o de sonido y un rápido desplazamiento de los ángulos de cámara. Eventualmente, sin embargo, el cerebro comienza a habituarse a la situación, dándose cuenta de que estos golpes son sólo falsas alarmas, y comienza a desconectarse de nuevo.
Como resultado, cada diez años más o menos la industria de la televisión ha tenido que subir la apuesta haciendo golpes emocionales y sustos cada vez más grandes, hasta que finalmente lo que tenemos hoy son estallidos periódicos de imágenes violentas en los dibujos de los niños y así sucesivamente, hasta el punto en el que hay un promedio de dieciséis golpes de violencia cada media hora.

Mermar las capacidades
En cuanto a los juegos de computadora, “si bien se los considera más estimulantes que mirar pasivamente un teleteatro, la evidencia muestra que aun este medio interactivo se asocia con una actividad neurológica sólo limitada. Un estudio sobre las diferencias en el flujo cerebral entre chicos jugando con la computadora y chicos haciendo ejercicios aritméticos muy simples, como la suma de números de un solo dígito, mostró que los juegos de computadora estimulaban sólo las partes del cerebro asociadas con la visión y el movimiento, mientras que la suma aritmética activaba áreas muy diversas”. Según Sigman, “ver televisión, en chicos de menos de tres años, puede tener efectos nocivos sobre la habilidad matemática y la capacidad y comprensión en la lectura”.

El ser humano al nacer no está totalmente desarrollado (ya lo sabemos todos), y continúa su proceso de maduración durante mucho tiempo. Al igual que a un recién nacido no se le puede ofrecer leche de vaca ni pescado porque su sistema digestivo no está preparado para asimilarlo, tampoco se le puede "ofrecer" cualquier programa de televisión. La razón, inicialmente, no es el contenido del programa (la información que nos da, que desde luego nunca debería ser mala), sino la velocidad de las imágenes.
Otro de los riesgos de exponer a la TV a los bebes es que impedimos el desarrollo de su vista. La vista en el recién nacido sufre al igual que el resto de órganos un proceso de maduración que teóricamente está completo a los dos años. Hasta entonces, el cerebro humano "aprende" a ver los "bordes" de los objetos, pasando de ser borrosos a ser nítidos (plasticidad neuronal). Para eso es necesario que los objetos estén "quietos" o con "poco movimiento". Esta es la razón por la que no se recomienda ver la TV a los menores de dos años, porque habitualmente todas las escenas son muy rápidas y con muchos cambios, distorsionando este proceso de aprendizaje de la vista. La televisión, literalmente, impide el crecimiento neuronal en el cerebro en desarrollo de los niños. Cuando los niños pequeños la ven, “anula la capacidad del cerebro para crear una imagen interna de algo o alguien, o de algún evento que no haya sido visto en el medio
Ambiente”. La televisión anula la esencia de lo que llamamos “imaginación”. Los investigadores solían pensar que era sólo el contenido de la programación el que estaba afectando negativamente a los niños. Ahora tenemos pruebas de que la tecnología y el dispositivo son muy perjudiciales por sí mismos. En otras palabras: el simple acto de ver la televisión (programas y publicidad) tiene efectos profundamente negativos en la fisiología de los seres humanos.
Durante el desarrollo del cerebro se van formando conexiones entre los dos hemisferios cerebrales a través del cuerpo calloso, las conexiones neuronales se van mielinizando. Las neuronas tienen una capa protectora de ácidos grasos que facilita la transmisión del impulso nervioso. Este proceso se ve favorecido con la estimulación sensorial y motora. De ahí la gran importancia del movimiento en los primeros años.
Las niñas mielinizan su vías neurales utilizando el cerebro. Una rica dieta sensorial y el sano movimiento ayudan a la formación de conexiones neurales flexibles y fuertes: cuantas más conexiones, mejor. El movimiento saludable, la repetición, el juego, la conversación y la estimulación multisensorial son esenciales para el desarrollo del cerebro. Ahora pensemos si todo esto tiene lugar cuando un niño ve la televisión, en primer lugar el movimiento es nulo o muy escaso.
Otro de los problemas a los que se enfrentan los más pequeños es el de “sentir” si las imágenes de la televisión y del ordenador son reales o no. La TV es un medio engañoso como para exponer a los niños que están aprendiendo a abrirse camino en el mundo cotidiano. Uno de los efectos del uso del ordenador o de los videojuegos de forma excesiva es la repetición constante de un número limitado de leves movimientos con las manos, como teclear y apretar el ratón, esto puede tensar las manos, los tendones, los músculos, los nervios y los huesos de las niñas en edades sensibles. El ordenador es para los niños pequeños una especie de camisa de fuerza tecnológica para el cuerpo. La falta de ejercicio perjudica también a la educación y al estudio, ya que el movimiento es esencial para un aprendizaje saludable. El movimiento activa la mente y el cuerpo, capacitándonos para integrar y asimilar nueva información.
“Hago luego entiendo”, el movimiento activa el crecimiento físico, sensorial e intelectual, y las niñas cuyo movimiento físico es limitado pueden padecer un crecimiento retrasado de sus facultades aparentemente no relacionada con el movimiento, como la habilidad para comprender conceptos. Aprendemos con todo el cuerpo.

Cerebro reptil
Aquí, la naturaleza del contenido del programa no importa. Mientras que el cerebro superior, o neocórtex, sabe que las imágenes en la televisión no son reales, el menor, o el cerebro “reptil”, no lo sabe. Esto significa que cuando un niño ve la televisión y ve violencia, el cerebro reptil envía una serie de mensajes de alarma hasta el cerebro emocional, que a su vez contacta inmediatamente con el corazón. En el momento en que el corazón recibe una indicación de negatividad o de peligro, rompe de su habitual modo armónico en uno incoherente, provocando la liberación de la hormona más potente en el cuerpo humano, conocida como cortisol. El cortisol inmediatamente despierta el cerebro y hace que se produzcan billones de conexiones neuronales con el fin de preparar el individuo para enfrentarse a esa emergencia.
Entonces, tan pronto como el corazón recibe el mensaje de que el peligro era falso y no hay problema, otra hormona se libera para disolver todas las vías neurales hechas para hacer una rápida reacción de adaptación a la amenaza percibida.
El problema con la actual programación televisiva es que no hay descanso, y el cerebro de un niño promedio, que ha observado desde 5.000 hasta 6.000 horas a la edad de cinco o seis años, está viviendo una gran confusión como resultado. El enorme exceso de estímulo de la televisión (programas y publicidad) hace que el cerebro se dañe y mal adapte de una manera que antes se pensaba imposible.

Age and Severity of Heart Failure Associated With Impairment in Verbal Memory

Older patients with lower rates of left ventricular ejection fraction (a measure of how well the left ventricle of the heart pumps with each contraction) appear more likely than younger patients to have significantly reduced verbal memory function, according to a report in the August issue of Archives of Neurology, one of the JAMA/Archives journals.

Three decades ago, researchers began investigating the association of heart failure with cognitive decline, according to background information in the article. Thirty to 80 percent of patients with heart failure may experience some cognitive deficits. However, research seeking to clarify the correlation of cognitive impairment with decreased left ventricular ejection fraction (EF), a measurement of the severity of heart failure, has generated inconsistent results. "Conflicting evidence about the association of EF with cognitive function suggests a complex relationship between patient variables and the cardiovascular factors that influence cognition," write the authors.
Joanne R. Festa, Ph.D., from St. Luke's­-Roosevelt Hospital Center, New York, and colleagues conducted a cross-sectional study to investigate the relationship between age, EF and memory among patients with heart failure. The participants, all adult patients with heart failure, underwent neurocognitive assessment while being evaluated for potential heart transplantation candidacy between September 2006 and September 2008. The testing included verbal and visual memory, attention, executive functioning and self-reported depressive symptoms. Researchers also recorded participants' EF, heart failure cause, medical history, current medications and demographic information. Echocardiography was used to measure EF, which was scored at less than 30 percent or at 30 percent or greater. Age quartiles used by the researchers were 45 years or younger, 46 to 55 years, 56 to 62 years and 63 years or older.
A total of 207 participants were included in the final analysis of the study; 38 had an EF of 30 or greater, and 169 had an EF of less than 30. Stable memory function was maintained across EF levels in patients younger than 63 years, but in older patients a significant association with worse memory performance was noticed when EF was less than 30 percent. Analysis of the results demonstrated that the components of memory with which low EF had the greatest association were verbal delayed recall and recognition.
"In summary, an interaction exists between the age and EF such that older patients with low EF had significantly reduced memory, particularly verbal delayed recall and recognition," write the researchers. However, the association of low EF with "memory in these patients is not entirely explained by EF." The authors suggest further research into additional mechanisms of cognitive dysfunction in patients with heart failure.

Via: sciencedaily

Botox For Urinary Incontinence For MS Or Spinal Cord Injury Patents, Positive Opinion In Europe

Crazy, but true......

The Irish Medicines Board has given a positive opinion for Botox (botulinum toxin type A) for urinary incontinence management in adults with NDO (neurogenic detrusor overactivity) resulting from neurogenic bladder due to multiple sclerosis or stable sub-cervical spinal cord injury, Allergan Inc. has announced.

Allergan says this step is an important one toward securing national licences in 14 European nations which are involved int he Mutual Recognition Procedure. The positive opinion came after the Irish regulatory agency evaluated Allergan's successful global Phase III program.

Bladder dysfunction affects approximately 60% to 80% of people with multiple sclerosis (MS) and 75% to 80% of those with spinal cord injury (SCI), including urinary incontinence, a condition that can cause considerable distress.

Both MS and SCI patients often have bladders which contract during the filling stage, during which time they should be relaxed - this condition is known as neurogenic detrusor overactivity. This overactivity can result in uncontrolled urinary leaking, known as urinary incontinence.

By injecting Botox into the bladder muscle, the involuntary contractions subside and bladder activity increases, resulting in fewer urinary leaking incidents; in some cases the problem resolves completely.

Approximately 11,000 patients are diagnosed annually with SCI in Europe and about 656,000 individuals live with MS. A sizeable percentage of these people remain professionally and socially active, even though they face chronic mobility problems.

Urinary incontinence is often a socially isolating and disabling condition. Sufferers frequently experience low self esteem, loss of independence, embarrassment, and depression. MS and SCI patients with urinary incontinence are also more likely to develop skin irritations and ulcers, recurrent urinary tract infections and kidney failure. If overactivity of the detrusor muscle is not treated there is also a risk of serious health complications.

Northern Humans Had Bigger Brains, to Cope With the Low Light Levels, Study Finds

The farther that human populations live from the equator, the bigger their brains, according to a new study by Oxford University. But it turns out that this is not because they are smarter, but because they need bigger vision areas in the brain to cope with the low light levels experienced at high latitudes.

Scientists have found that people living in countries with dull, grey, cloudy skies and long winters have evolved bigger eyes and brains so they can visually process what they see, reports the journal Biology Letters.
The researchers measured the eye socket and brain volumes of 55 skulls, dating from the 1800s, from museum collections. The skulls represented 12 different populations from across the globe. The volume of the eye sockets and brain cavities were then plotted against the latitude of the central point of each individual's country of origin. The researchers found that the size of both the brain and the eyes could be directly linked to the latitude of the country from which the individual came.
Lead author Eiluned Pearce, from the Institute of Cognitive and Evolutionary Anthropology in the School of Anthropology, said: 'As you move away from the equator, there's less and less light available, so humans have had to evolve bigger and bigger eyes. Their brains also need to be bigger to deal with the extra visual input. Having bigger brains doesn't mean that higher latitude humans are smarter, it just means they need bigger brains to be able to see well where they live.'
Co-author Professor Robin Dunbar, Director of the Institute of Cognitive and Evolutionary, said: 'Humans have only lived at high latitudes in Europe and Asia for a few tens of thousands of years, yet they seem to have adapted their visual systems surprisingly rapidly to the cloudy skies, dull weather and long winters we experience at these latitudes.'
That the explanation is the need to compensate for low light levels at high latitudes is indicated by the fact that actual visual sharpness measured under natural daylight conditions is constant across latitudes, suggesting that the visual processing system has adapted to ambient light conditions as human populations have moved across the globe.
The study takes into account a number of potentially confounding effects, including the effect of phylogeny (the evolutionary links between different lineages of modern humans), the fact that humans living in the higher latitudes are physically bigger overall, and the possibility that eye socket volume was linked to cold weather (and the need to have more fat around the eyeball by way of insulation).
The skulls used in the study were from the indigenous populations of England, Australia, Canary Islands, China, France, India, Kenya, Micronesia, Scandinavia, Somalia, Uganda and the United States. From measuring the brain cavity, the research suggests that the biggest brains belonged to populations who lived in Scandinavia with the smallest being Micronesians.
This study adds weight to other research that has looked at the links between eye size and light levels. Other studies have already shown that birds with relatively bigger eyes are the first to sing at dawn in low light. The eyeball size across all primates has been found to be associated with when they choose to eat and forage -- with species with the largest eyes being those that are active at night.

Inner visions of seven dimensional space

I recomend this article [pdf] from the American Mathematical Society about blind mathematicians.


I was surprised to learn that the majority work in geometry, supposedly the most ‘visual’ discipline, and fascinated to learn that they generally believe the experience of sight puts people at a disadvantage because it locks us into a perception-led view of space.

This can be a problem in geometry because it regularly works in problems that involve more than three dimensions or requires an understanding of objects from all ‘angles’ simultaneously.

Alexei Sossinski points out that it is not so suprising that many blind mathematicians work in geometry. The spatial ability of a sighted person is based on the brain analyzing a two-dimensional image, projected onto the retina, of the three-dimensional world, while the spatial ability of a blind person is based on the brain analyzing information obtained through the senses of touch and hearing. In both cases, the brain creates flexible methods of spatial representation based on information from the senses. Sossinski points out that studies of blind people who have regained their sight show that the ability to perceive certain fundamental topological structures, like how many holes something has, are probably inborn…
Sossinski also noted that sighted people sometimes have misconceptions about three-dimensional space because of the inadequate and misleading twodimensional projection of space onto the retina. “The blind person (via his other senses) has an undeformed, directly 3-dimensional intuition of space,” he said.

There is not any maths in the article but it is written for mathematicians so it contains lots of mysterious sentences like “Morin first exhibited a homotopy that carries out an eversion of the sphere in 1967″.
However, the article is also a fantastic history of blind mathematicians and has lots of quotes from current leaders in the field who explain who their supposed disability lets them better understand the maths of three and more dimensions.
Even for those without a maths background it’s an amazing insight into some remarkable people.

pdf of ‘The World of Blind Mathematicians’

La meditación nos protege del envejecimiento cerebral

Estimados Amigos les comparto una entrevista a Vicente Simón, para los que no lo conocen, Vicente Simón es  Catedrático de Psicobiología de la Universidad de Valencia. Hace una década, mientras leía textos de filosofía oriental, decidió aprender la práctica de la meditación. E inevitablemente se interesó por entender cómo afectaba esa práctica a nuestro cerebro. En la actualidad es uno de los principales expertos en la neurobiología del mindfulness o atención plena, una técnica basada en la meditación budista que, según los últimos estudios científicos, puede modificar el cerebro.

Pregunta. La meditación ha irrumpido con fuerza en occidente...
Respuesta. La verdad es que tanto el estudio de la neurobiología cerebral como de la aplicación clínica de mindfulness se encuentran ahora en un periodo de crecimiento explosivo. Estamos asistiendo a un incremento exponencial del interés por estos temas, yo creo que porque la humanidad intuye, de alguna manera, que está en riesgo real de "autodestruirse" y busca la orientación de lo que se ha llamado desde siempre la “sabiduría perenne”.

P: ¿Qué cambia en nuestro cerebro cuando practicamos atención plena o mindfulness?
R: Aunque estamos muy lejos de comprender todo lo que pasa en el cerebro durante la práctica, recientemente se ha publicado una investigación que arroja bastante luz sobre la actividad cerebral en la meditación. Cuando no está ocupada en una tarea concreta, nuestra mente tiende a implicarse en procesos narrativos, en los que relaciona el pasado con el futuro y construye la entelequia del "self" personal. Esta actividad se produce en redes neuronales localizadas en las zonas mediales de la corteza prefrontal, que son zonas con una actividad muy intensa en los humanos modernos que nos diferencian de otras especies.

P: Demasiado ajetreo neuronal…
R: Podríamos decir que ese ajetreado quehacer cerebral se encuentra al servicio de la supervivencia humana. Tratamos de construir modelos del futuro basándonos en nuestras experiencias del pasado. Procuramos preveer lo que va a suceder, a fin de poder planificar mejor nuestra conducta e incrementar así nuestras posibilidades de subsistir y de prosperar. El problema es que, cuando esta función se activa demasiado, vivimos constantemente en el futuro, siendo presas del temor o del deseo. Vivimos para lo que ha de pasar (que es algo ilusorio) y comenzamos a dejar de vivir en la realidad de lo que pasa. Sin embargo, cuando dedicamos nuestra atención a lo que está sucediendo en el momento presente, decrece la actividad de estas zonas mediales de la corteza prefrontal y entran en juego circuitos nerviosos situados más lateralmente en el cerebro. Son instantes en los que, en lugar de vagar por los cerros de Úbeda, nuestra mente se centra en lo que estamos viviendo en ese momento.

P: Y para que todo eso se convierta en un hábito hay que entrenarse mentalmente.
R: Así es. Al entrenarnos en mindfulness, es decir, al hacer meditación, lo que hacemos fundamentalmente es abandonar la actividad de esa mente errante, también llamada “mente de mono” porque nuestra mente, igual que un mono brinca de rama en rama, va “saltando” de tema en tema. Entonces concentramos nuestra atención en lo que está sucediendo en el presente, bien en nuestro cuerpo, bien en el mundo exterior. Dejamos de rumiar sobre el pasado y de preocuparnos acerca del futuro. Eso es bueno porque, en lugar de activar continuamente los circuitos de la supervivencia, ponemos también en marcha los circuitos de la felicidad.

P: Entonces, ¿nuestro cerebro es “moldeable”, puede cambiar?
R: Por supuesto. No hay ninguna duda de que incluso el cerebro adulto posee una considerable capacidad de adaptación. Si yo, por ejemplo, comenzara ahora a jugar al golf, o a aprender chino, ciertas zonas de mi cerebro se modificarían para crear el sustrato neuronal necesario para llevar a cabo esas actividades. Desde luego, serían zonas muy diferentes en cada uno de las dos tareas y, probablemente, no llegaría a alcanzar mucha maestría en ninguna de esas disciplinas. Respecto a la meditación, hay un trabajo muy interesante del equipo de Sara Lazar que, utilizando técnicas de resonancia magnética, demuestra que la práctica de la meditación incrementa el grosor de ciertas zonas cerebrales relacionadas con la atención, el procesamiento sensorial y la interocepción. Otro aspecto muy interesante de ese trabajo es que presenta indicios de que la meditación es capaz de contrarrestar el adelgazamiento que sufren, con la edad, ciertas zonas cerebrales. Es decir, que la meditación nos protegería de algunas consecuencias del envejecimiento cerebral.

P: ¿Y cómo ayuda el mindfulness a combatir la depresión o la ansiedad?
R: En el caso de la depresión, sabemos que la meditación puede disminuir la frecuencia de las recaídas en nuevos episodios depresivos. Al parecer, esto sucede porque, al meditar, pasamos menos tiempo dedicados a pensamientos negativos y cavilando sobre nuestras preocupaciones. De hecho, el tratamiento y prevención del estrés es el tema que originó, históricamente, la aplicación de mindfulness a la práctica clínica. Fue Jon Kabat-Zinn quien utilizó una combinación de meditación y de yoga para aliviar el sufrimiento de pacientes crónicamente estresados, bien por razones médicas (como el dolor de espalda, el cáncer, las cardiopatías y otras patologías crónicas), bien por razones psicológicas, por estar sometidos a situaciones estresantes de larga duración y padecer ansiedad, depresión  o insomnio. También se ha demostrado que la práctica de mindfulness contribuye a reducir la ansiedad, ya que activa las zonas cerebrales responsables de la modulación del miedo.

P: Sorprendente...
R: Y hay más. Meditar facilita la aparición de estados de ánimo positivos, pues incrementa la actividad del hemisferio cerebral izquierdo. Los ejercicios de mindfulness aumentan la capacidad de empatía y de comunicación, facilitando así las relaciones interpersonales. También incrementa la auto-comprensión, haciendo posible que interpretemos mejor el sentido de la propia vida. Todos estos factores contribuyen a disminuir el estrés y a que nos sintamos más dueños de las situaciones que vivimos y, en general, de nuestras vidas.

P: El próximo día 31 de octubre imparte un seminario para profesionales de la salud en Madrid, organizado en colaboración con el Centro Wellmind. ¿Qué va a contarle a los asistentes?
R: Trataré es de comunicarles mi entusiasmo por la práctica de mindfulness y transmitirles las enormes posibilidades que ofrece vivir la vida de una forma diferente a cómo habitualmente lo hacemos. La práctica de mindfulness nos descubre un mundo nuevo, que no es otro que aquel en el que ya vivimos, pero visto desde una perspectiva radicalmente distinta. Se trata de acceder a un estado de conciencia diferente. En nuestras vidas, la actividad turbulenta de nuestras mentes hiperactivas no nos deja distinguir con claridad lo que es importante y lo que es accesorio y, en general, andamos persiguiendo objetivos que nos crean todavía más problemas y tensiones de las que ya tenemos. Al apaciguar la mente, vamos descubriendo lo que realmente importa y acabamos intuyendo cuál es el camino que conduce a la verdadera felicidad.