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Prosthetic Hand Capable of Delivering Texture Sensations
Zothecula writes: A new prosthetic system allows amputees to feel familiar sensations and also, somewhat unexpectedly, reduces their phantom pain. Researchers at Case Western Reserve University and the Louis Stokes Cleveland Veterans Affairs Medical Center developed the system to reactivate areas of the brain that produce the sense of touch, but recipients of prosthetic hands reported their phantom pain subsiding almost completely after being hooked up to the system.
Seems to me that when some area of your body doesn't get much or any stimulation for long periods of time, it gets more sensitive. If you lose a limb the associated sensory nerves get zero stimulation, as well as the associated area of the brain. Wouldn't those nerves and that part of your brain 'turn up the gain' and experience more 'noise' in the absence of 'signal' (hence 'phantom pain')? Then you attach something that provides a 'signal' again; 'gain' goes down, S/N ratio goes up?
Are YOU using the TOOL, or is the TOOL using YOU? Think about it!
Can anyone here explain to me the issue if/how we can map nerves correctly?
For example: suppose someone's finger gets cut off, and then surgeons manage to reattach it.
I assume that since there are many distinct sensory nerve endings on a finger, each of those must be carried along a distinct electrical pathway up to the brain.
When a surgeon reattaches a finger, does he/she somehow get all of those hundreds(?) of connections to be lined up properly so that the mapping is the same as it was before the accident? If so, how? If not, what happens?
"A new prosthetic system allows amputees to feel familiar sensations and also, somewhat unexpectedly, reduces their phantom pain."
This seems like one of those things that people might very reasonably not think of ahead of time but which seems blindingly obvious in retrospect. It would probably be expected that if you managed to reattach a severed limb that there wouldn't be any phantom pain afterward. ("Real" pain during the healing process yes, and perhaps lingering aches as one might have with any injury, but not phantom pain.) You'd also expect the same to hold true if you managed to grow a new arm and attach it properly.
But a simple prosthetic isn't enough to prevent or cure phantom pain. So one would expect that at _some_ point in the process between no nerve connections with a peg leg (or equivalent) and full connection with a regrown/reattached limb that the phantom pain would disappear. I guess they just encountered that point earlier than they might have expected.
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