Removing part of the brain can induce inner peace, according to researchers from Italy. Their study provides the strongest evidence to date that spiritual thinking arises in, or is limited by, specific brain areas.

To investigate the neural basis of spirituality, Cosimo Urgesi, a cognitive neuroscientist at the University of Udine, and his colleagues turned to people with brain tumours to assess the feeling before and after surgery. Three to seven days after the removal of tumours from the posterior part of the brain, in the parietal cortex, patients reported feeling a greater sense of self-transcendence. This was not the case for patients with tumours removed from the frontal regions of the brain.

“Self-transcendence used to be considered just by philosophers and crank new age people,” says co-author Salvatore Aglioti, a cognitive neuroscientist at the Sapienza University of Rome. “This is the first really close-up study on spirituality. We’re dealing with a complex phenomenon that’s close to the essence of being human.”

The authors pinpointed two parts of the brain that, when damaged, led to increases in spirituality: the left inferior parietal lobe and the right angular gyrus. These areas at the back of the brain are involved in how we perceive our bodies in spatial relation to the external world. The authors of the study in the journal Neuron1, say that their findings support the connection between mystic experiences and feeling detached from the body.

“The most surprising part was the rapidity of the change,” says Urgesi. “This discovery shows that some complex personality traits are more malleable than previously thought.”

Reasoning Project

In a tail wagging the dog reversal, researchers have found that simple chemical reactions can mix a solution. Usually, chemicals are stirred to enhance a reaction, but a new study finds that the reverse is also true: Simple chemical reactions can trigger fluid flows, reports a paper in the January 29 Physical Review Letters.

The research has implications for many chemical reactions, including those inside stars or when carbon dioxide stored deep in the earth encounters water, says study coauthor Anne De Wit of the Université Libre de Bruxelles in Belgium.

De Wit and her colleagues wondered what would happen to fluid flows if the reacting liquids were left alone and not stirred. The researchers watched a very simple reaction — the neutralization that occurs between hydrochloric acid and sodium hydroxide, a common chemical base — in the absence of stirring.

The researchers carefully injected the denser sodium hydroxide into a container and then added the hydrochloric acid. The sodium hydroxide stayed on the bottom and the hydrochloric acid sat on top. Where the two reactive chemicals met, the reaction’s products — table salt and water — began to form. As the salty solution formed, it crept upward and hit the lower-density acid, creating tendrils that started to mix the solution. But the same didn’t happen below the reaction line. This difference in how the reaction product interacted with each of its chemical parents drove the mixing the team observed.

These asymmetrical patterns, the researchers say, distinguish mixing during a chemical reaction from what happens when two nonreactive liquids meet, which may look more like diffusion or other kinds of mixing.

“These kinds of beautiful patterns can be observed with very well-known reactions,” says study coauthor Christophe Almarcha, also of the Université Libre de Bruxelles. “This is quite fascinating for someone who’s done this reaction hundreds of times.”

The researchers also describe reaction-driven mixing mathematically by creating a model that predicted a pattern that looked like the real thing. The model can be tweaked to predict patterns for other chemical reactions, which would vary widely, Almarcha says.

“Our little model system says ‘pay attention,’” De Wit says. “If there are reactions, then new things will happen.” For instance, if stored carbon leaches into an aquifer and starts reacting with water, “those reactions will trigger flows, which will enhance the mixture,” she says.

Image and Video: C. Almarcha/Université Libre de Bruxelles

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I learned an interesting fact about Fibonacci numbers recently. Fibonacci numbers can be used to approximately convert from miles to kilometers and back.

Here is how.

Take two consecutive Fibonacci numbers, for example 5 and 8. And you’re done converting. No kidding – there are 8 kilometers in 5 miles. To convert back just read the result from the other end – there are 5 miles in 8 km!

Another example. Let’s take the consecutive Fibonacci numbers 21 and 34. What this tells us is that there are approximately 34 km in 21 miles and vice versa. (The exact answer is 33.79 km.)

If you need to convert a number that is not a Fibonacci number, just express the original number as a sum of Fibonacci numbers and do the conversion for each Fibonacci number separately.

For example, how many kilometers are there in 100 miles? Number 100 can be expressed as a sum of Fibonacci numbers 89 + 8 + 3. Now, the Fibonacci number following 89 is 144, the Fibonacci number following 8 is 13 and the Fibonacci number following 3 is 5. Therefore the answer is 144 + 13 + 5 = 162 kilometers in 100 miles. This is less than 1% off from the precise answer, which is 160.93 km.

Another example, how many miles are there in 400 km? Well, 400 is 377 + 21 + 2. Since we are going the opposite way now from miles to km, we need the preceding Fibonacci numbers. They are 233, 13 and 1. Therefore there are 233 + 13 + 1 = 247 miles in 400 km. (The correct answer is 248.55 miles.)

Just remember that if you need to convert from km to miles, you need to find the preceding Fibonacci number. But if you need to convert from miles to km, you need the subsequent Fibonacci number.

If the distance you’re converting can be expressed as a single Fibonacci number, then for numbers greater than 21 the error is always around 0.5%. However, if the distance needs to be composed as a sum of n Fibonacci numbers, then the error will be around sqrt(n)·0.5%.

Here’s why it works.

Fibonacci numbers have a property that the ratio of two consecutive numbers tends to the Golden ratio as numbers get bigger and bigger. The Golden ratio is a number and it happens to be approximately 1.618.

Coincidentally, there are 1.609 kilometers in a mile, which is within 0.5% of the Golden ratio.

Now that we know these two key facts, we can figure out how to do the conversion. If we take two consecutive Fibonacci numbers, F_n+1 and F_n, we know that their ratio F_n+1/F_n is 1.618. Since the ratio is approximately the same as kilometers per mile, we can write F_n+1/F_n = [mile]/[km]. It follows that F_n·[mile] = F_n+1·[km], which translates to English as “n-th Fibonacci number in miles is the same as (n+1)-th Fibonacci number in kilometers”.

That’s all there is to it. A pure coincidence that the Golden ratio is almost the same as kilometers in a mile.

A system that turns brain waves into FM radio signals and decodes them as sound is the first totally wireless brain-computer interface.

For now, 26-year-old Erik Ramsey, left almost entirely paralyzed by a horrific car accident 10 years ago, can only express vowel sounds with the system. That’s less than can be accomplished with wired brain-computer interfaces. But it’s still a promising step.

“All the groups working on BCIs are working toward wireless solutions. They are very superior,” said Frank Guenther a Boston University cognitive scientist who helped developed Ramsey’s system.

In the last decade, brain-computer interfaces, or BCIs, have made the jump from speculation to preliminary medical reality. Since Wired reported on quadriplegic BCI pioneer Matthew Nagle four years ago (”He’s playing Pong with his thoughts alone“), the interfaces have been used to steer wheelchairs, send text messages and even to Tweet. They’re so advanced that some researchers now worry about BCI ethics — what happens when healthy people get them? And they’re concerned about the threat posed by hackers.

But as amazing as these early BCIs are, they’re far from street-ready. Systems based on translating electrical signals captured by electrodes on patients’ scalps are notoriously slow, capable of producing about one word a minute. If researchers put electrodes directly into patients’ brains, the results are better — but that raises the possibility of dangerous infection. And from a purely practical point of view, wires just get in the way.

The implant system tested by Ramsey, as described in a paper published Wednesday in Public Library of Science ONE, was originally developed by Philip Kennedy, founder of Neural Signals, a company that specializes in BCIs. Several electrodes are implanted in Ramsey’s cerebral cortex. Beneath the skin of his skull is an amplifier that gathers the electrodes’ signals, and an FM transmitter that sends them to a nearby computer.

Using a neurological model constructed by Guenther, Ramsey’s brain activity is mapped to corresponding mouth and jaw movements. Another program decodes the signals, and synthesizes them in the sound of a tinny, but human-like voice.

“The system produces the sound output in about 50 milliseconds. That’s the time it takes for sound output to come from a motor cortex command in a normal individual,” said Guenther.

The three wires in Ramsey’s brain are only sufficient for making vowel sounds, said Guenther. But the researchers plan to add more electrodes, perhaps as many as 32. That would be more difficult to control, but would also allow Ramsey’s thoughts to better mimic natural tongue and jaw movements, ultimately letting him form consonants as well.

For now, the computer that translates Ramsey’s mental broadcasts is still in a laboratory. “But our goal is to have him transmit directly to a laptop,” said Guenther.

Image: A schematic at left and CT scans at right of the wireless brain-computer interface. PLoS ONE.

[Brandon Keim]