9 February 2010
A “brain fart” is a term for an inexplicably stupid error in a straightforward task made by someone with abundant skill and experience. We are all prone to them.
The latest research show that brain farts are a unique type of cognitive mistake. Unlike errors caused by lack of information or experience, or by distractions. They have a predictable neural pattern that emerges up to 30 seconds before they happen.
When you are absorbed in inward-focused thinking such as daydreaming, a collection of brain regions jointly called the default mode network (DMN) starts furiously popping away. Neuroscientists don’t agree on exactly which parts of the brain compose this network, but they now believe it is one of the busiest neurological systems.
The DMN, while still somewhat mysterious, seems to play many critical roles in overall brain function. It may facilitate the processing of external stimuli by acting as a sort of bushwhacker, carving out communications pathways in the brain. It may foster imagination and creativity. It also appears to be the main culprit in brain farts.
Basically, your brain will take any opportunity to shut down some of its processing systems. Here’s the process step by step:
t-10 minutes
You’re daydreaming, and your medial temporal lobe subsystem, precuneus, medial prefrontal subsystem, and posterior cingulate cortex, which together make up the default mode network (DMN) are all active.
t-5 minutes
You confront a demanding task, such as driving home. Your anterior cingulate and right prefrontal regions, brain areas involved in attention, begin to activate, as do the cerebellum and the parietal, visual, and temporal cortices, which control the motor coordination you need to pilot through traffic. At the same time, the DMN deactivates.
t-30 seconds
Your route is extremely familiar. Your frontal lobes, bored by this habitual task, begin to power down. The retrosplenial cortex in the posterior section of the DMN begins to stir again. When the balance of activity between the DMN and the attention network reaches a certain threshold, you enter an error-prone state. You miss your exit off the highway.
t+5 seconds
Your frontal lobes fire up again at high levels in an attempt to compensate for the error. They return to a state of optimal performance, ready to work on a corrective action.
t+15 seconds
The stress of having made a blunder activates the limbic-hypothalamic-pituitary-adrenal axis, your brain’s “panic button.” You experience a surge of the stress hormone cortisol.
[Source]
Chapter: Health
8 February 2010
CT scans deliver far more radiation than has been believed, and may contribute to 29,000 new cancers each year, along with 14,500 deaths.
One study found that people may be exposed to up to four times as much radiation as estimated by earlier studies. While previous studies relied on dummies equipped with sensors, authors of the new paper studied more than 1,000 patients at four hospitals.
Based on their measurements, a patient could get as much radiation from one CT scan as 74 mammograms or 442 chest X-rays.
Young people are at highest risk from excess radiation, partly because they have many years ahead of them in which cancers could develop. Among 20-year-old women who get one coronary angiogram, a CT scan of the heart, one in 150 will develop cancer related to the procedure.
[Source]
Chapter: Health
5 February 2010
Scientists have developed an adhesive with many possible medical uses, including repairing bone fractures, based on a glue produced by the sandcastle worm.
The worm creates a complex water-based mortar to create a home from grains of sand and bits of shell. The adhesive can stick to wet surfaces and doesn’t dissolve at certain pH levels, making it ideal for medical applications. Once it has done its job, it can become water-soluble and dissolve.
The traditional method of healing broken bones by using metal nails, pins and screws is difficult with smaller bones and scientists have been looking for a suitable adhesive substitute for decades.
So far, the glue has passed toxicity tests and is at least as strong as Super Glue and twice the strength of the sandcastle worm’s formula.
[Source]
Chapter: Health
3 February 2010
While artificial sweeteners may be able to confuse your taste buds, the suspicion is growing that your brain is not so easily fooled.
In one study, researchers had eight cyclists perform 60-minute workouts on a stationary bike while measuring their work rate. During workouts on separate days they were told to rinse their mouth with a solution of either glucose or saccharin, without swallowing either one. The glucose mouth rinse improved the cyclists’ performance by a small but consistent amount compared to saccharin.
Later, they were asked to rinse their mouths with either saccharin alone or saccharin plus a caloric (but non-sweet) sugar called maltodextrin. The cyclists did slightly better when they rinsed their mouths with maltodextrin, even though both solutions carried identical saccharin taste.
When scientists performed fMRI scans on the athletes, they found that the combination of saccharin and maltodextrin activated two reward-associated brain areas — the striatum and anterior cingulate — which saccharin alone failed to touch.
In another study by neuroscientist Paul Smeets, volunteers were given two version of a beverage, one sweetened with sugar, the other with a blend of artificial sweeteners. The brain scans showed that the artificially sweetened beverage failed to activate an area of the brain called the caudate nucleus, which is an area associated with rewards.
A recent study by Guido Frank, a psychiatrist at the University of Colorado in Denver looked into how the brain responds to sucralose (artificial sweetener) and sucrose. He gave the sweetener and the sugar to 12 women, adjusting the concentrations so that the sweetness of the two matched. When he looked at their brain responses with functional magnetic resonance imaging (fMRI), he saw clear differences.
These studies suggest that the brain has a way of detecting calories while food is still in your mouth.
[Source]
Chapter: Health, Sugar
2 February 2010
The U.S. Centers for Disease Control and Prevention has released its latest assessment of the chemicals people are carrying around in their bodies.
The biomonitoring study is the most comprehensive in the world, measuring 212 chemicals in the blood and urine of 8,000 Americans. That’s more than 40% more chemicals than have ever been tested for before.
The CDC highlighted a few chemicals because they are both widespread — found in all or most people tested — and potentially harmful. Here’s a look at what they are and how you can try to avoid them.
Polybrominated diphenyl ethers
Better known as “flame retardants” PBDEs are used widely in all sorts of goods — from foam furniture to electronics — to reduce fire risk. They also accumulate in human fat, and some studies suggest they may harm the liver and kidneys as well as the neurological system. Some states, including California, Washington and Maine, have restricted the use of certain PBDEs deemed the highest health risk. Short of such bans, avoiding them is difficult because the chemicals are integrated into so many common products.
Bisphenol A
BPA, which is found in many plastics, in the lining of cans and even coating many sales receipts, was found in more than 90% of Americans tested. The health concerns about BPA are many and growing. While BPA-free products are available, it can be difficult to choose them unless you do research ahead of time. The Daily Green has a list of many products containing BPA to help.
PFOA
PFOA and other perfluorinated chemicals found in most Americans are used to create heat-resistant and non-stick coatings on cookware, as well as grease-resistant food packaging and stain-resistant clothing. Studies have linked these chemicals to a range of health problems, including infertility in women, and to liver, immune system, developmental and reproductive problems in lab animals. Avoiding them can be difficult, but avoiding products that contain them is a first step.
Acrylamide
Formed when carbohydrates are cooked at high temperatures (French fries anyone?) and as a byproduct of tobacco smoke, acrylamide and its metabolites are extremely common in Americans. While the risks of low-level exposure aren’t well known, high-level exposure has caused cancer and neurological problems in lab animals and workers, respectively. Avoiding it in food comes down to food choice, storage and preparation, according to the Food and Drug Administration. Examples include boiling or baking potatoes, rather than frying them, or soaking them in water before frying; toasting bread only lightly; and moderating the drinking of coffee, which gets acrylamide in the roasting process.
Mercury
The main source of mercury — a potent neurotoxin that can lead to permanent brain damage if young children or fetuses are exposed — continues to be contaminated fish. To avoid mercury, you have to educate yourself about which fish are safe. Several guides exist to help make a smart choice at the fish counter.
MTBE
This gasoline additive has been phased out of use in the U.S., in favor of ethanol, but it still can be detected widely in American’s bodies. (It has contaminated many drinking water supplies.) While the health risks are not well defined, studies have linked it to a variety of potential problems, including neurological and reproductive damage.
[Source]
Chapter: Health
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