[extropy-chat] why do we stop laughing?

[Spike]

> Spike:
> 
> ...people start to laugh,
> then something must happen in our brains to adjust
> something.  Otherwise we would keep on laughing at
> that joke indefinitely... 

...Which would presumably be a fatal condition.  The
indefinite-laugher would be rendered unable to eat.  She 
might attempt to do so, but the partially-masticated viands
would spew from her nose (the way milk used to do when
you were in the elementary school lunch room and everything
was funny back then.  Later in high school only things that were
somehow related to sex were funny.)  The sight of the jolly 
victim's nose spewing food would be so hilarious that the rest 
of the tribe might be taken out in a gleeful, even if painful,
demise.  Perhaps the stop-laughing mechanism evolved
as a survival of the soberest thing.

Did you laugh just now?  What caused you stop?  What is
*different* in your brain now compared to half a minute ago?
Why don't humans die laughing?

spike