Followup to: The Strangest Thing An AI Could Tell You
Brain damage patients with anosognosia are incapable of considering, noticing, admitting, or realizing even after being argued with, that their left arm, left leg, or left side of the body, is paralyzed. Again I'll quote Yvain's summary:
After a right-hemisphere stroke, she lost movement in her left arm but continuously denied it. When the doctor asked her to move her arm, and she observed it not moving, she claimed that it wasn't actually her arm, it was her daughter's. Why was her daughter's arm attached to her shoulder? The patient claimed her daughter had been there in the bed with her all week. Why was her wedding ring on her daughter's hand? The patient said her daughter had borrowed it. Where was the patient's arm? The patient "turned her head and searched in a bemused way over her left shoulder".
A brief search didn't turn up a base-rate frequency in the population for left-arm paralysis with anosognosia, but let's say the base rate is 1 in 10,000,000 individuals (so around 670 individuals worldwide).
Supposing this to be the prior, what is your estimated probability that your left arm is currently paralyzed?
Added: This interests me because it seems to be a special case of the same general issue discussed in The Modesty Argument and Robin's reply Sleepy Fools - when pathological minds roughly similar to yours update based on fabricated evidence to conclude they are not pathological, under what circumstances can you update on different-seeming evidence to conclude that you are not pathological?
It could be apocryphal, and it doesn't help that it seems like something I heard about a long time ago, but as far as I know, when you start to drown the best of your intentions are overcome by your instinct for self preservation. However, Google turns up a result from the Telegraph about a recent case in which someone may indeed have drowned himself in a bucket of water, although there seems to be some confusion over the case. Thanks for calling me on it -- I really am now, in fact, not certain I couldn't.
I couldn't think of a better example at the time, though, so the spirit of the argument will have to stand in for its questionable veracity.
When an inmate is found drowned in a bucket of water in a cell with three other inmates, my first theory is not suicide while the other inmates are sleeping.