The science of prosthetics has evolved from the wooden stump, through the metal hook, through the plastic look-alike, through a limb with robotic function, to today’s limb with robotic function controlled by the brain. Commonly these prostheses replace an appendage, but we can replace hearts and can almost replace lungs and livers, too.
But what if it’s your brain that needs replacement, due to stroke, injury, autism, Alzheimer’s, cerebral palsy, or the like? Enter neurocognitive prosthetics, which are (or will be) implants that support or take the place of malfunctioning regions of the brain.
If this sounds far-fetched, consider the fact that we already do this with cochlear implants that replace the eardrum and directly stimulate the auditory nerves. And the next step—not simply stimulating the brain, but acting as the brain—is in the works.
The hippocampus is a fairly straightforward region of the brain. If it works, you can code new memories; if it doesn’t, you can’t. Basically, it accepts electrical stimuli and emits corresponding electrical results, like a complex series of ricochets. The same stimulus produces the same response every time. Despite its simplicity and despite the fact that it’s one of the brain’s most studied regions, exactly how it works is anyone’s guess.
The innovation of researchers at the University of Southern California was in not caring how it works. Instead, they realized that what matters is its function: Electricity enters one place and leaves at another. If they could simply reproduce the in/out pattern, they could replicate its function without caring about the workings inside the black box. So they simply fired electricity into the maze and charted where it came out … millions and millions of times. They then programmed these inputs and outputs onto a computer chip.
That was in 2003. Recent artificial hippocampus chatter is way down since the initial wow factor, but the device continues to work its way through rats toward monkeys, and most involved with the project agree that it’s only a matter of time before it hits humans.
Hatchibombotar via Flickr.com
Eye Hack: Cornsweet Illusion
Which half of this rectangle is lighter? The right half, of course! Actually, they’re exactly the same shade; only, a gradient in the center goes from dark to light, implying the change in shade. To check, cover the centerline and compare the two sides.
