What’s Up For May 2016?

Look! A scientist who says more scrutiny is needed! Yea!

AND - “Don’t try this at home!”

Cadaver study casts doubts on how zapping brain may boost mood, relieve pain

Earlier this month, György Buzsáki of New York University (NYU) in New York City showed a slide that sent a murmur through an audience in the Grand Ballroom of New York’s Midtown Hilton during the annual meeting of the Cognitive Neuroscience Society. It wasn’t just the grisly image of a human cadaver with more than 200 electrodes inserted into its brain that set people whispering; it was what those electrodes detected—or rather, what they failed to detect.

When Buzsáki and his colleague, Antal Berényi, of the University of Szeged in Hungary, mimicked an increasingly popular form of brain stimulation by applying alternating electrical current to the outside of the cadaver’s skull, the electrodes inside registered little. Hardly any current entered the brain. On closer study, the pair discovered that up to 90% of the current had been redirected by the skin covering the skull, which acted as a “shunt,” Buzsáki said.

The new, unpublished cadaver data make dramatic effects on neurons unlikely, Buzsáki says. Most tDCS and tACS devices deliver about 1 to 2 milliamps of current. Yet based on measurements from electrodes inside multiple cadavers, Buzsaki calculated that at least 4 milliamps—roughly equivalent to the discharge of a stun gun—would be necessary to stimulate the firing of living neurons inside the skull. Buzsáki notes he got dizzy when he tried 5 milliamps on his own scalp. “It was alarming,” he says, warning people not to try such intense stimulation at home.

Buzsáki expects a living person’s skin would shunt even more current away from the brain because it is better hydrated than a cadaver’s scalp. He agrees, however, that low levels of stimulation may have subtle effects on the brain that fall short of triggering neurons to fire. Electrical stimulation might also affect glia, brain cells that provide neurons with nutrients, oxygen, and protection from pathogens, and also can influence the brain’s electrical activity. “Further questions should be asked” about whether 1- to 2-milliamp currents affect those cells, he says.

Buzsáki, who still hopes to use such techniques to enhance memory, is more restrained than some critics. The tDCS field is “a sea of bullshit and bad science—and I say that as someone who has contributed some of the papers that have put gas in the tDCS tank,” says neuroscientist Vincent Walsh of University College London. “It really needs to be put under scrutiny like this.”

Rare Pics Of The Infamous ’50s London Girl Gang Photographed by Ken Russell Are Unbelievably Cool

On this day, 14th February 1779,  Captain James Cook was killed in Hawaii.

James Cook completed three major voyages of discovery. On his first, departing in 1768, he commanded the ‘Endeavour’ on an expedition to chart the transit of Venus. He returned to England in 1771, having also circumnavigated the globe, including exploring and charting New Zealand and Australia’s eastern coast. 

On his second journey (1772-1775), he commanded the 'Resolution’ and the 'Adventure’ on an expedition to the South Pacific, disproving the rumour of a great southern continent, exploring the Antarctic Ocean, New Hebrides and New Caledonia.

Cook’s third and final voyage (1776-1779) of discovery was an attempt to locate a North-West Passage, an ice-free sea route which linked the Atlantic to the Pacific Ocean. Again, Cook commanded the Resolution while Charles Clerke commanded Discovery. Leaving England in 1776, Cook first sailed south to Tahiti to return Omai, a Tahitian man, to his home. Omai had been taken on Cook’s second voyage and had been an object of curiosity in London. It was on this, Cook’s final voyage, that he discovered the Hawaiian Islands in January 1778. This major discovery would lead to his death – Cook was killed on a return visit to Hawaii at Kealakekua Bay, on 14 February 1779.  

Kealakekua Bay was considered the sacred harbour of Lono, the fertility god of the Hawaiians. Cook and his compatriots were welcomed as gods but after one of the crewmen died, exposing the Europeans as mere mortals, relations became strained. On February 4, 1779, the British ships sailed from Kealakekua Bay, but rough seas damaged the foremast of the Resolution, and after only a week at sea the expedition was forced to return to Hawaii.

The Hawaiians greeted Cook and his men by hurling rocks; they then stole a small cutter vessel from the Discovery. Negotiations with King Kalaniopuu for the return of the cutter collapsed after a lesser Hawaiian chief was shot to death and a mob of Hawaiians descended on Cook’s party. The captain and his men fired on the angry Hawaiians, but they were soon overwhelmed, and only a few managed to escape to the safety of the Resolution. Captain Cook himself was killed by the mob. A few days later, the Englishmen retaliated by firing their cannons and muskets at the shore, killing some 30 Hawaiians. The Resolution and Discovery eventually returned to England.

The State Library of New South Wales holds significant original sources relating to James Cook, these paintings from the collection depict the death of Captain Cook.

Carved ditty box shaped like a coffin on silver stand, containing a rough watercolour sketch of the death of Cook, including a lock of Cook’s hair, ca. 1779 / carved by sailors on Cook’s last ship HMS Resolution. State Library of NSW.

Everyday Phenomena: The Maillard Reaction

At first glance, steak, French fries, bread, milk caramel, and soy sauce don’t have very many similarities. However, the preparation of these foods all have one thing in common: browning that occurs via the Maillard (my-YAR) reaction.

The Maillard reaction was first discovered in 1912 by Louis-Camille Maillard, and refers to a long chain of reactions that ultimately leads to browning of food. This chain typically begins with the condensation of an amine (often the amino acid lysine) with a reducing sugar (containing an aldehyde); one example of this Amadori rearrangement is shown above with lysine and glucose.

This Amadori product can react in a variety of different ways, including dehydration and deamination to produce a diverse array of molecules that give browned food a distinctive flavor; a few of these compounds are shown above. At the end of the sequence of reactions that occur during browning is a class of polymeric compounds known as melanoidins, which lend a brown color to the food.

Below about 140°C (280°F), the Maillard reaction does not proceed at an appreciable rate, although alkaline conditions (such as the lye used to make pretzels) can accelerate the process. Without this reaction, many foods we enjoy now wouldn’t be nearly as tasty!

Further Reading: Hodge, J. E., J. Agric. Food Chem. 1953, 1 (15), 928-943 (Full text)

On this date in 1884, the first edition of what would become the Oxford English Dictionary was published under the name A New English Dictionary on Historical Principles; Founded Mainly on the Materials Collected by The Philological Society. Research for the OED had begun in 1857, when the Philological Society in London established an “Unregistered Words Committee” to find words that were either poorly defined, or absent from contemporary dictionaries. When the list of unregistered words outnumbered the amount of words found in nineteenth-century dictionaries, the group decided to write their own. The Oxford University Press agreed to publish the dictionary in 1879, and the group published the first fascicle – which covered A to Ant –in 1884 to disappointing sales. It wasn’t until 1928 that the final fascicle was published, totaling 128 fascicles in total.

In 1933, a thirteen-volume set including all fascicles and a one-volume supplement went on sale under its current name: Oxford English Dictionary – only seventy-six years in the making!

Pictured above is our well-loved copy of that historic first fascicle, which includes the preface to the dictionary and entries A through Ant. While the volume is huge and a little intimidating, it was only the beginning to what would become the most comprehensive dictionary in the English language.

Ed. James A.H. Murray. A New English Dictionary on Historical Principles; Founded Mainly on the Materials Collected by The Philological Society v. 1. Oxford: Clarendon Press, 1888. 423 M96 v. 1.

Aphasia: The disorder that makes you lose your words

It’s hard to imagine being unable to turn thoughts into words. But, if the delicate web of language networks in your brain became disrupted by stroke, illness or trauma, you could find yourself truly at a loss for words. This disorder, called “aphasia,” can impair all aspects of communication. Approximately 1 million people in the U.S. alone suffer from aphasia, with an estimated 80,000 new cases per year.  About one-third of stroke survivors suffer from aphasia, making it more prevalent than Parkinson’s disease or multiple sclerosis, yet less widely known.

There are several types of aphasia, grouped into two categories: fluent (or “receptive”) aphasia and non-fluent (or “expressive”) aphasia. 

People with fluent aphasia may have normal vocal inflection, but use words that lack meaning. They have difficulty comprehending the speech of others and are frequently unable to recognize their own speech errors. 

People with non-fluent aphasia, on the other hand, may have good comprehension, but will experience long hesitations between words and make grammatical errors. We all have that “tip-of-the-tongue” feeling from time to time when we can’t think of a word. But having aphasia can make it hard to name simple everyday objects.  Even reading and writing can be difficult and frustrating.

It’s important to remember that aphasia does not signify a loss in intelligence. People who have aphasia know what they want to say, but can’t always get their words to come out correctly. They may unintentionally use substitutions, called “paraphasias” – switching related words, like saying dog for cat, or words that sound similar, such as house for horse. Sometimes their words may even be unrecognizable.  

So, how does this language-loss happen? The human brain has two hemispheres. In most people, the left hemisphere governs language.  We know this because in 1861, the physician Paul Broca studied a patient who lost the ability to use all but a single word: “tan.” During a postmortem study of that patient’s brain, Broca discovered a large lesion in the left hemisphere, now known as “Broca’s area.” Scientists today believe that Broca’s area is responsible in part for naming objects and coordinating the muscles involved in speech. Behind Broca’s area is Wernicke’s area, near the auditory cortex. That’s where the brain attaches meaning to speech sounds. Damage to Wernicke’s area impairs the brain’s ability to comprehend language. Aphasia is caused by injury to one or both of these specialized language areas.

Fortunately, there are other areas of the brain which support these language centers and can assist with communication.  Even brain areas that control movement are connected to language. Our other hemisphere contributes to language too, enhancing the rhythm and intonation of our speech. These non-language areas sometimes assist people with aphasia when communication is difficult.

However, when aphasia is acquired from a stroke or brain trauma, language improvement may be achieved through speech therapy.  Our brain’s ability to repair itself, known as “brain plasticity,” permits areas surrounding a brain lesion to take over some functions during the recovery process. Scientists have been conducting experiments using new forms of technology, which they believe may encourage brain plasticity in people with aphasia.  

Meanwhile, many people with aphasia remain isolated, afraid that others won’t understand them or give them extra time to speak. By offering them the time and flexibility to communicate in whatever way they can, you can help open the door to language again, moving beyond the limitations of aphasia.

Complex learning dismantles barriers in the brain

Biology lessons teach us that the brain is divided into separate areas, each of which processes a specific sense. But findings published in eLife show we can supercharge it to be more flexible.

Scientists at the Jagiellonian University in Poland taught Braille to sighted individuals and found that learning such a complex tactile task activates the visual cortex, when you’d only expect it to activate the tactile one.

“The textbooks tell us that the visual cortex processes visual tasks while the tactile cortex, called the somatosensory cortex, processes tasks related to touch,” says lead author Marcin Szwed from Jagiellonian University.

“Our findings tear up that view, showing we can establish new connections if we undertake a complex enough task and are given long enough to learn it.”

The findings could have implications for our power to bend different sections of the brain to our will by learning other demanding skills, such as playing a musical instrument or learning to drive. The flexibility occurs because the brain overcomes the normal division of labour and establishes new connections to boost its power.

It was already known that the brain can reorganize after a massive injury or as a result of massive sensory deprivation such as blindness. The visual cortex of the blind, deprived of its input, adapts for other tasks such as speech, memory, and reading Braille by touch. There has been speculation that this might also be possible in the normal, adult brain, but there has been no conclusive evidence.

“For the first time we’re able to show that large-scale reorganization is a viable mechanism that the sighted, adult brain is able to recruit when it is sufficiently challenged,” says Szwed.

Over nine months, 29 volunteers were taught to read Braille while blindfolded. They achieved reading speeds of between 0 and 17 words per minute. Before and after the course, they took part in a functional Magnetic Resonance Imaging (fMRI) experiment to test the impact of their learning on regions of the brain. This revealed that following the course, areas of the visual cortex, particularly the Visual Word Form Area, were activated and that connections with the tactile cortex were established.

In an additional experiment using transcranial magnetic stimulation, scientists applied magnetic field from a coil to selectively suppress the Visual Word Form Area in the brains of nine volunteers. This impaired their ability to read Braille, confirming the role of this site for the task. The results also discount the hypothesis that the visual cortex could have just been activated because volunteers used their imaginations to picture Braille dots.

“We are all capable of retuning our brains if we’re prepared to put the work in,” says Szwed.

He asserts that the findings call for a reassessment of our view of the functional organization of the human brain, which is more flexible than the brains of other primates.

“The extra flexibility that we have uncovered might be one those features that made us human, and allowed us to create a sophisticated culture, with pianos and Braille alphabet,” he says.

I just completed the finishing touches on my new poster, a detailed map of the Mandelbrot Set in a vintage style. I’m calling it the Mandelmap.

The Mandelbrot Set is a fractal shape with infinite detail that you can zoom in on. I often explore the Mandelbrot Set to find trippy patterns to create gifs with, but when I started I felt like I was just poking around at random. So I wanted to create a printed guide for myself to find my way around… I soon realized this was going to be a lot of work, so I decided I might as well take it to the next level and make an awesome poster that would be not just for myself but for everyone else to enjoy too.

What you see here is the result of more than a year’s research, planning, and execution. It’s a 36x24 inch poster rendered fully at 300 dpi, and everything you see was created from scratch. I will be posting more updates and information as I get the test prints in, and I hope to have this poster available to buy within the next couple months!

www.mandelmap.com

i think the coolest thing would be to see a new color

Reenactor throws a spear at a drone