(Source: buttsbutts)
The 1st solar eclipse in the U.S. in 18 years will take place this Sunday, May 20. Find out where you can see it.
Did you know that neurons come in a variety of extraordinary shapes? Imaged above is Ferris Jabr’s drawing, based on reconstructions and drawings by neuroanatomist Santiago Ramón y Cajal, of different types of neurons: A. Purkinje cell B. Granule cell C. Motor neuron D. Tripolar neuron E. Pyramidal Cell F. Chandelier cell G. Spindle neuron H. Stellate cell. In addition to their varying shapes, they each have different functions.
Some neurons send electrical signals along fibers that stretch several feet; other neurons’ branches extend only a few millimeters away from the cell body. Some neurons possess a fractal beauty similar to that of ferns and corals: Purkinje cells, for example, often sport finely branched nets, like a sea fan. But some of their neighbors look more like tangled tumbleweeds. One neuron might appear more or less round under the microscope—like a firework frozen in climax—whereas another might spider through the brain like a daddy longlegs.
Excitatory neurons mostly stimulate other cells; inhibitory neurons prefer to stifle. Most neurons fire in patterns, but their tempos vary: some keep a steady beat, others remain largely silent except for the occasional burst of activity and still other cells continually fire like a trigger-happy toddler playing laser tag.
This is a part of Ferris Jabr’s Know Your Neurons series where he will be exploring the “cellular diversity of the nervous system.” He goes on to explain the discovery and naming of the neuron.
Best Illusion of the Year - Disappearing Hand Trick
A combination of visual, touch and position illusions come together in this freaky winner’s video. Gives me the willies just thinking about it. The illusion is part of a project to simulate sensory loss in stroke patients.
Popular Health Supplements: The Scientific Evidence
The value of various dietary supplements is sometimes hard to evaluate, given the conflicting reports and misinformation often transmitted by the media and marketing departments. Presented here is a rather brilliant infographic that visualises popular dietary supplements according to their tangible health benefits as supported by scientific evidence.
The image is presented as a “balloon race”, where the higher the bubble indicates the greater the scientific evidence for its effectiveness. Importantly, the supplements are only effective for those conditions listed inside the bubble. Some supplements also appear in multiple bubbles as they have been shown to affect a range of conditions, but the evidence varies.
Head here for the updated interactive version.
Paralyzed Woman Controls Robotic Arm With Her Mind
The world is just freaking amazing. Imagine being trapped in a body with barely functioning motor control for 15 years. This woman has lived that life, after having a stroke.
Thanks to Leigh Hochberg’s team at Brown University, a tiny chip implanted in her brain now lets her control a robotic arm. It’s called BrainGate2. She can reach out, grab, and manipulate objects with no more effort than her thoughts. The same effort that each of us make when we move our own arms.
This is such a heartwarming example of dedicated, hardcore scientific research affecting lives for the better. Just look at her face as she sips from the thermos (it’s at about 1:55, and you might get some dust in your eye).
Sure, space is an amazing frontier for inspiration. But if that doesn’t work out, we’ve got a whole lot of lives to change down here. And science is getting a great start.
Previously: A paralyzed man controls a prosthetic arm with his mind, high fives his girlfriend for the first time in years. (Additional face-water warning)
(via Wired Science)
Christina Agapakis details the many ways that we have harnessed living creatures to make photo-like images. At top left, photosynthetic cyanobacteria migrate to where light is shined in a petri dish, seeking energy, and appearing as pigment. At right, a shadow image of the word “FERN” is projected over a leaf, causing the chloroplasts to migrate to the surface and appear as shading.
More unique bio-photography from bacteria to grass at her blog, Oscillator.
Why We Dream: Real Reasons Revealed
The slumbering mind might not seem like an apt tool for any critical thinking, but humans can actually solve problems while asleep, researchers say. Not only that, but one purpose for dreaming itself may be to help us find solutions to puzzles that plague us during waking hours.
Dreams are highly visual and often illogical in nature, which makes them ripe for the type of “out-of-the-box” thinking that some problem-solving requires, said Deirdre Barrett, a psychologist at Harvard University.
Barrett’s theory on dreaming, which she discussed at the Association for Psychological Science meeting here last month, boils down to this: Dreaming is really just thinking, but in a slightly different state from when our eyes are open.
“Whatever the state we’re put in, we’re still working on the same problems,” Barrett said. Although dreams might have initially evolved for a different purpose, they likely have been refined over time so they can serve double-duty: help the brain reboot itself and problem-solve.
Dreams and evolution
A theory to explain dreams, or any human behavior for that matter, needs to take into account evolution, Barrett said. But many early theories of dreaming either didn’t address evolution at all, or downright contradicted it, she said.
For instance, Sigmund Freud proposed dreams exist to fulfill our wishes. But such gratification in an imaginary world would do little to help us adapt our instincts to the physical world, which is one key point of evolution, Barrett said.
Others have proposed dreams are more of a side effect of the sleep cycle. Dreams usually occur during Rapid Eye Movement, or REM, sleep. This stage is thought to serve several functions: to rest a part of the brain (since some areas are active while others aren’t) and to replenish brain chemicals, such as neurotransmitters.
This has led some to say that dreams happen simply because REM sleep happens, Barrett said. The psychologist Steven Pinker once likened dreams to computer screen savers, saying that it perhaps “doesn’t really matter what the content is as long as certain parts of the brain are active.”
However, Barrett disagrees. “My opinion is that, evolution just isn’t wasteful, that when things evolve for one purpose, that generally they don’t continue throughout time to have only that purpose, but anything else that may be useful about them gets refined,” she said in a telephone interview with LiveScience prior to the convention.
She also noted that REM sleep has been around for quite some time, since mammals evolved some 220 million years ago. “The longer something has existed during evolutionary history, the likelier it is to have other functions overlaid on it,” she said at the convention.
Problem-solving
Barrett has studied problem-solving in dreams for more than 10 years, and documented many examples of the phenomenon.
In one experiment, Barrett had college students pick a homework problem to try to solve in a dream. The problems weren’t rocket science; they were fairly easy questions that the student simply hadn’t gotten around to solving yet. Students focused on the problem each night before they went to bed. At the end of a week, about half the students had dreamed about the problem and about a quarter had a dream that contained the answer, Barrett said.
So at least in the cases where problems are relatively easy, some people can solve them in their sleep.
Barrett has also extensively reviewed scientific and historical literature, looking for examples of problems solved in dreams.
She found examples of almost every type of problem being solved in a dream, from the mathematical to the artistic. But many were related to problems that required individuals to visualize something in his or her mind, such as an inventor picturing a new device.
The other major category of problems solved in dreams included “ones where the conventional wisdom is just wrong about how to approach the problem,” Barrett said.
Dreams might have evolved to be particularly good at allowing us to work out puzzles that fall into those two categories, she said.
“I think that dreams and REM sleep have probably further evolved to be useful for really as many of the things that our thinking is useful for,” Barrett said. “It’s just extra thinking time, so potentially any problem can get solved during it, but it’s thinking time in the state that’s very visual and looser in associations, so we’ve evolved to use it especially to work on those kinds of problems.”
(via scinerds)
