The Itch (2008)
newyorker.com
newyorker.com
We're used to thinking of perception as reading a live feed of sensory input, but actually there's evidence that the brain holds on to a persistent memory of its best guess about the outside world, and new sensory information merely updates that best guess in a simple bayesian manner. When nerve endings die for some reason, no update can occur, which sometimes causes the brain to persist in an erroneous state for a very long time. Because this theory is not widely publicized among doctors (or laymen), the condition of being stuck in an erroneous brain state is often confused for the misfirings of severed nerve endings or a psychiatric disorder such as OCD. In one particular example, a woman remained stuck with an itchy sensation which did not subside for years on end and which eventually caused her to scratch through her skull thus waking up to brain matter on her pillow. In another case a man feels as if his hand is much larger than it is despite being consciously aware of its actual size. The fact that sometimes this sort of condition can be alleviated by providing the brain with illusory input (for instance, a mirror based trick showing a left part of the body as the right or vice versa) simultaneously lends credence to this theory and serves as an effective therapy.
^There. I just saved you like 15 min on M's irrelevant foray into graduating a prestigious university, getting married, getting divorced, getting hooked on heroin, contracting HIV, and being misdiagnosed in like 5 different ways before getting to the substance of the article. You're welcome.
The Itch (2008) - https://news.ycombinator.com/item?id=12096650 - July 2016 (17 comments)
The Itch (2008) - https://news.ycombinator.com/item?id=8359390 - Sept 2014 (8 comments)