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SIGHT
How does a "bionic eye" allow blind people to see?
A company called Second Sight has developed a new retinal prosthesis that can provide sight to people who have gone blind from degenerative eye diseases like macular degeneration and retinitis pigmentosa. Second Sight's retinal technology consists of five main parts:
And get this: The whole thing runs on a battery pack. Read more at HowStuffWorks...
How Artificial Vision Will Work
By some estimates, there are more than 10 million people worldwide affected by retinal diseases that lead to loss of sight. Several groups of scientists have already developed silicon microchips that can create artificial vision. The devices, called artificial silicon retinas (ASR), have scientists looking at three important aspects:
Another technology in development, called the artificial retina component chip (ARCC), will give blind patients the ability to see 10x10 pixel images, which is about the size of a single letter on this page. However, researchers have said that they could eventually develop a version of the chip that would allow a 250x250 pixel array, which would enable those who were once blind to read a newspaper. Read more at HowStuffWorks...
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STRENGTH
How can adrenaline help you lift a 3,500-pound car?
In 2006 in Tucson, Ariz., Tim Boyle watched as a car hit 18-year-old Kyle Holtrust. The car pinned Holtrust, still alive, underneath. Boyle ran to the scene of the accident and lifted the Camaro off the teenager while the driver of the car pulled him to safety. What accounts for feats of superhuman strength such as this one? Are they glimpses into the lives of superheroes' alter egos? Or are all of us imbued with amazing strength?
Although well-documented when they do occur, feats of hysterical strength -- unnatural and amazing strength tapped during high-stress situations -- are not recognized by medical science. This is largely due to the problem of gathering evidence: Instances like these come about without warning, and to reproduce these situations in a clinical setting would be unethical and dangerous.
But we are aware of the effects of adrenaline, a hormone shown to increase strength to amazing degrees for short periods of time. Read More at HowStuffWorks...
How Pain Works
What happens when you're cutting a bagel and slice your hand with the knife? You'll probably feel an immediate sharp pain, followed by a longer-lasting dull ache. Eventually, both sensations will go away. But how? And what exactly is pain?
Pain is the most common reason people seek medical attention, but is also hard to define because it's a subjective sensation. The International Association for the Study of Pain defines it as an "unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage."
Obviously, this definition is pretty vague. One physician even remarked that pain is whatever the patient says it is. So let's just say that pain is a warning sensation to your brain that some type of stimulus is causing or may cause damage, and you should probably do something about it.
Pain perception, or nociception (from the Latin word for "hurt"), is the process by which a painful stimulus is relayed from the site of stimulation to the central nervous system. Nociception requires several components:
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SENSATION
How Lie Detectors Work
Perhaps you've seen them in movies and thought, "I could fool that lie detector machine." But could you really? Polygraphs, commonly called "lie detectors," are instruments that monitor a person's physiological reactions. But, despite their nickname, they don't "detect" lies. They can only detect whether deceptive behavior is being displayed. This is done in three key ways:
Now that you know the basics, let's peek into the lives of polygraph examiners, look at some high-profile cases in which lie detectors were integral, and explore the countermeasures and legalities around polygraph testing. Read More at HowStuffWorks...
How BrainPort Works
A blind woman sits in a chair holding a video camera focused on a scientist sitting in front of her. She has a device in her mouth, touching her tongue, and there are wires running from that device to the video camera. The woman has been blind since birth and doesn't really know what a rubber ball looks like, but when the scientist rolls it in her direction, she puts out a hand to stop it.
The blind woman saw the ball. Through her tongue.
Well, not exactly through her tongue, but the device in her mouth sent visual input through her tongue in much the same way that seeing individuals receive visual input through the eyes. In both cases, the initial sensory input mechanism -- the tongue or the eyes -- sends the visual data to the brain, where that data is processed and interpreted to form images. It’s called electrotactile stimulation for sensory augmentation or substitution, an area of study that involves using encoded electric current to represent sensory information -- information that a person cannot receive through the traditional channel -- and applying that current to the skin, which sends the information to the brain. Read More at HowStuffWorks...
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BRAIN POWER
How does the brain create an uninterrupted view of the world?
If you've ever used a camcorder, you've probably noticed that the picture can be pretty shaky as you move from one image to the next. But for most of us, our eyes -- the video cameras of our brain, if you will -- suffer no unstable transition as they move quickly over a scene.
Scientists have understood this phenomenon for decades. To achieve a stable view despite quick eye movements, the eyes do an amazing thing: They take before and after shots of every focused image and compare them in order to confirm stability. In essence, before your eyes actually sense an object, your brain takes its own picture of it for comparison purposes. It knows where your eyes are going to move next, and it forms an image of the object that precedes our conscious, visual perception of it and lays the framework for a smooth visual transition.
So the process is in the books. But scientists have spent at least 50 years trying to find out how the brain manages this feat. Read More at HowStuffWorks...
How can someone stay awake for 11 days?
Have you ever pulled an all-nighter to study for a test or get a project done for work? How about doing it 11 days in a row?
On May 24, 2007, Tony Wright, a 42-year-old horticulturalist, claimed to have beaten the record of 264 hours (exactly 11 days) set in 1964. Wright had some practice: He had already been through more than 100 sleep deprivation experiments, with the longest one lasting eight days. He also employed a unique diet that comprised only raw foods. Of course, long-term sleep deprivation can cause vision problems, hallucinations, paranoia, mood swings, difficulty communicating or understanding others, a compromised immune system, and depression and is not recommended by doctors. But stunts like this have triggered questions about human’s need for sleep. Read more about Cornwall and take a peek into his diary at HowStuffWorks.
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