Here’s the idea. Here’s a good video demonstration:
I figure the effect ought to be reversible. In the case of phantom limb pain, the switch in the brain is stuck in the “Ow!” position and it isn’t receiving new feedback from the severed limb. The mirror box sends a new signal “See? Your hand is fine” which sets the switch to “Not ow” (and it stays there in the absence of new feedback, because the nerves were severed with the limb).
Rather than relieving pain in phantom limbs, it may be possible to tell the brain “You should be feeling pain in this spot right now. Adapt your nervous control system so that your experience matches your perception.” If it is possible to regrow the nerve, I think it will grow back more quickly after a few sessions with the mirror box. On the other hand, this may cause phantom pain without corresponding increase in motor control. So maybe it would be safer to tell the brain “See? You can make a fist.” Or something like that.
The quad I work with has one hand that can make a fist and the other one doesn’t. I think I’m going to suggest this to the crew that does his physical therapy and see if they think it’s crazy.
Edit: Unrelated Game tidbit. The fact that sensations in the feet can be remapped to the genitals (3rd video) suggests that we would expect to see IOIs in the feet if actual arousal occurs in a target. Probably in the form of general unrest and squirming, bouncing, changing position, etc. I intuit that hand/facial IOIs- more common in women?- indicate a desire to clutch or hold on to the person inspiring affection (rather than arousal).