Researchers from the University of Chicago and Sony are developing a wearable electrical muscle stimulation system that boosts your physical reaction time without making it feel like you've lost control of your body. The latter is particularly important when considering the development of exoskeletons and other systems that bring us physically closer to machines for augmenting human capabilities. The system essentially zaps your muscles into contracting at precisely the right time while making it seem as if you're still controlling the movement. From IEEE Spectrum:
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The typical reaction time for a human is about 250 milliseconds—meaning it takes you about a quarter of a second after you see something to physically react to it. But the researchers explain that "our conscious awareness of intention takes a moment to arise, around 200 ms." In other words, it takes you about 200 milliseconds for your brain to turn sensory input into a decision to do something like move a muscle, and then another 50 or so milliseconds for that muscle to actually start moving. The researchers suggest that this 50-ish millisecond gap between intention and action is a window that they can exploit to make humans react more quickly while still feeling like the action they take is under their control.
The video below shows a series of experiments that demonstrate how reflexes can be usefully accelerated without decreasing the sense of control, or agency, that the user experiences. It turns out that an EMS-driven improvement in reflexes of up to 80 milliseconds is possible while still maintaining the user's sense of agency, which is the difference between success and failure in these particular experiments.
For reasons unknown, up to half of of people who freeze to death are found partially or completely naked. DNews looks into the phenomenon of paradoxical undressing. Read the rest
The Guinness World Record for breath-holding belongs to Aleix Segura Vendrell, who managed 24 minutes and 3 seconds floating in a pool. How do Vendrell and others, like free divers and, er, David Blaine (see below) do it? Psychological training is obviously the first step, says Clayton Cowl, chair of preventive occupational and aerospace medicine at the Mayo Institute. But there's physiology at work too. From Smithsonian:
Olympic swimmers seem to be able to go great distances without breathing, but that is primarily due to aerobic conditioning, says Cowl. Those athletes are more efficient at getting oxygen into the tissue and extracting carbon dioxide. That allows them to breathe more effectively, and potentially, improve their breath holding.
Just being in the water may confer additional breath-holding ability. All mammals have what is known as a diving reflex. The involuntary reflex is most obvious—and pronounced—in aquatic mammals like whales and seals. But humans have this reflex, also. The purpose seems to be to conserve the oxygen that is naturally stored throughout the body, according to one study.
When a mammal dives into the water, the heart rate slows, and the capillaries of extremities like arms and legs—or flippers—constrict. Blood and oxygen is redirected towards the internal organs. The reflex helps diving animals override the need to breathe, which means they can stay underwater longer.
"What’s the Longest You Can Hold Your Breath?" (Smithsonian)
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My friends at Youth Radio interviewed a sports medicine physician, who used to dance with Cirque du Soleil, about the anatomy of "bone breaking," the incredible form of turf dancing where the performers rhythmically contort, pop, and flex their bodies in crazy ways.
Below, Youth Radio's earlier video about turf dancing.
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If the cells that make up your body are little factories, then the shipping department just picked up a Nobel Prize this morning with the award for physiology or medicine going to researchers Randy Schekman of the University of California at Berkeley, James Rothman of Yale University, and Thomas Südhof of Stanford. These scientists don't work together, but their research does overlap and play off each other in important ways. In fact, this isn't the first time some of these men have shared major research awards.
What makes their work so important? It's really all about increasing our understanding of how individual cells operate and participate in major bodily systems like immunity or hormone control. If you built little models of cells back in grade school, you probably have a mental image of them as a sort of lumpy sack with a couple of things inside — a big fat nucleus and some squirrelly little mitochondria, mostly. But it turns out that there's a lot more happening in the interior of a cell than that. Much of that activity is centered around vesicles — bubbles in the fluid that fills a cell. There are many different kinds of vesicles doing many different jobs, but one of the important things they do is move molecules, either within the cell or from the cell to the outside world. Read the rest
This chart describes the key problem with being Batman — it doesn't take a serious injury to seriously disable you. Your body can rack up big damage over years of repeated small stresses and strains — jumping from roof to roof two or three times a week, for instance, or slamming your knuckles into a bad guy's face every night.
Neuroscientist and kinesiologist Paul literally wrote the book on what it would take to create a non-superhuman superhero, like Batman. In a post at Scientific American blogs, he explains the major physical impacts of being the Dark Knight. His big conclusion: Nobody could be Batman for very long. And even after they retired, they'd feel the echo of what they'd done to their body every day for the rest of their lives.
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It’s hard to gauge the long-term effects of being exposed to these harsh occupations. Looking at NFL players provides another way to get at long term effects. In fact I used the very short average career—3-5 years—of NFL players as a way to estimate Batman’s longevity in Becoming Batman.
Skilled writer Peter King provided an in-depth expose on football players in the Dec 12, 2011 issue of Sports Illustrated. This piece was a follow up look at 39 members of the 1986 Cincinnati Bengals—25 years later—and spanned all forms of injury. But it’s the bodily injuries I want to focus on. In the category of “residual injury” over 70% had at least one surgery during their careers with ~40% having a post-NFL surgery for an injury related to football.
A 1956 video about the then-still-theoretical physiology of space travel ... with a special appearance by Chuck Yeager!
Last week, Mark told you about a giant eyeball that washed up on the beach in Florida. Today, the Florida Fish and Wildlife Conservation Commission released their preliminary analysis of who that eyeball once belonged to and how it likely ended up becoming the temporary toast of the Internet.
The Deep Sea News blog called it last week, but the official word from the experts is that this was the eye of a swordfish. The distinction is based on the size, the color, and the fact that there are bits of bone present around the edges (something you wouldn't see attached to a giant squid eye).
How do you get a swordfish eye without a swordfish attached? Simple: It's swordfish season. In the press release, Joan Herrera, curator of collections at the FWC’s Fish and Wildlife Research Institute in St. Petersburg, said that,
"Based on straight-line cuts visible around the eye, we believe it was removed by a fisherman and discarded."
But before we pack this mystery away, I think you should take one more close look at the giant eyeball, because it offers a great view a really interesting feature of fish eye anatomy. Fish eyes are similar to those of land-dwelling vertebrates. But there are some key differences. In particular, the shape of the lens... Read the rest
The Nobel Prizes in science will be announced — one prize per day — between now and Wednesday. Today, the winners of the prize for physiology or medicine were announced. John Gurdon and Shinya Yamanaka will share the award for work related to cloning and our ability to manipulate the functioning of stem cells.
What's interesting here is that the research these two men are winning the Nobel for happened nearly a generation apart. Gurdon's work was crucial to the development of cloning. You'll recall that some embryonic stem cells can grow up to be anything, any part of animal's living tissue. Differentiated stem cells, in contrast, are destined for a specific job — for instance, they could grow into skin cells, or nerve cells, but not both. In 1952, other scientists had concluded that you could take genetic material from a very early frog embryo, inject it into the egg cell of another frog, and get that to grow into a living animal — a clone. But those researchers thought this process would only work up to a point. They didn't think you could clone an adult, or even an older fetus. Gurdon proved them wrong. In a series of experiments published between 1958, 1962, 1966, he worked with older and older donor cells, and produced more developed clones — eventually growing fully adult, fertile frogs from cells taken from the intestines of tadpoles.
Yamanaka, meanwhile, did his research in the early part of the 21st century, developing the methods that allow us to trick grown-up, set-in-their-ways cells into behaving more like embryonic stem cells. Read the rest
Over at Discovery News, Emily Sohn asks the question I've been wondering for the last two weeks. Why are Olympians today better at their sports than Olympians of the past? Why do speed records keep getting broken? Why can gymnasts do more elaborate routines?
I mean, I have plenty of reasonable, speculative answers for those questions. But I hadn't seen them addressed in a factual way. This is great. And fascinating.
The answer, experts say, involves a combination of incremental technological improvements, as well as a growing population of people attempting a larger variety of sports that they start earlier and stick with longer. The mind plays a big role, too, especially when it comes to toppling seemingly insurmountable barriers, like the four-minute mile of the past or the two-hour marathon of the future.
"There is almost certainly a species limit in terms of physical capabilities, and I suspect we might be in the range of that," said Carl Foster, an exercise physiologist at the University of Wisconsin, Lacrosse. "But every time scientists say humans are not going to go any faster, they've been shown to be wrong. You can take that one to the bank."
Through calculations of maximum power output, oxygen use, heart function and other factors, some researchers have attempted to predict what the absolute limits of human ability will be. Much-debated estimates include 1:58 for the marathon (a five-minute improvement over the current men's record of 2:03.38), and 9.48 for the men's 100m.
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