The Science of Sarcasm (Not That You Care...)

Katherine P. Rankin, a Neuropsychologist, Studies Sarcasm - NYTimes.com -- Interesting tidbit on sarcasm and the brain, and why the demented just don't get it.

What you may not have realized is that perceiving sarcasm, the smirking
put-down that buries its barb by stating the opposite, requires a nifty mental
trick that lies at the heart of social relations: figuring out what others are
thinking. Those who lose the ability, whether through a head
injury or the frontotemporal dementias afflicting the patients in Dr.
Rankin’s study, just do not get it when someone says during a hurricane, “Nice
weather we’re having.”