Hacker News Reader

Comment by drooby | Hacker News Reader

It has been noticed that those with schizophrenia (not saying you have that) are able to tickle themselves.

The hypothesis is that people with schizophrenia are less able to predict their internal sensations - and because tickling is so tightly coupled exciting our brains expectation and predictions - they experience it as if someone else is doing it.

View on HN

I can tickle myself in several spots on my upper back, and I definitely don't think it feels like someone else is doing it (and don't have trouble predicting it from what I can tell, although I guess I've never been tested on that rigorously). If anything, my expectation of it causes it to be even more overwhelming (it's not something that I enjoy at all honestly regardless of whether it's me or someone else doing it; the best comparison I can make to it is like accidentally shocking yourself when brushing your finger against the metal when plugging something into an outlet, just not as strong and localized to the tickled spot).

On the other hand, I've noticed a fair number of other strange reactions that I sometimes get to sensations that I've occasionally seen other people online mention but have never met anyone else in person who also says they have them. One weird one is that when certain things vibrate in my hand (e.g. some but not all of the cell phones I've had and my Nintendo Switch's "rumble"), my inner ear will feel like it's shaking around, which is very unsettling. It seems to happen on the opposite ear of the hand my phone is being held (or both ears if both hands are touching). I can also sometimes replicate it by tickling parts of my lower face (in which case it happens on the same side as the part of my face touched), which makes me think it's due to some sort of actual physiological response to some extent rather than just some sort of weird resonance). From googling this in the past, there do seem to be other people who experience this, but I couldn't find any sort of documented research on it (presumably due to it being rare and benign enough not to merit anyone's attention).

oh damn

i can tickle myself reliably and in a bunch of diff places but pretty sure i'm otherwise normal. not a schizo not an autist so idk why... or at least pretty sure i'm not (◕‿◕)

Does that effect extend to sexual touch, e.g. masturbation? Has that ever been studied? I realize this is a strange observation.

My partner of a few years can do it and she couldn't be further from the representations in the literature or media (Sapolsky's lecture on it) that I've seen on schizophrenia; however, I'm not even remotely an expert in any of it.

ASD and schizophrenia share something in common: Both feature NMDA receptors functioning differently than in neurotypicals, which is a plausible cause for why some people are able to tickle themselves.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3808979/

https://pubmed.ncbi.nlm.nih.gov/17097347/

People with either are less likely to experience illusions. SlateStarCodex had a decent article that touched on the phenomenon a few years ago:

https://slatestarcodex.com/2017/06/28/why-are-transgender-pe...

I used to be able to tickle my own feet a little bit when my skin was drier, but I can't any more. I don't have any of the symptoms in that NIH doc. Unsure if related but I also receive no effects from morphine regardless of dosage. Nobody has been able to tell me why.

The neurotypicals susceptibility to illusions is IMHO a cohesion enhancing adaptation for life in large groups.

> It has been noticed

Source?

https://pubmed.ncbi.nlm.nih.gov/28500871/

Reply on news.ycombinator.com