people who study sleep?

this is going to sound stupid, but i dont know the title of someone who studies sleep. sleep doctor? sleep is very interesting to me and i would like to learn more about the different kind of careers it could offer. but i dont know the name of that career... or even the name of the field of sleep.. i guess im looking for an "ologist" term like biologist or neurologist etc. thank you very much.

Yahoo Answers results:
http://answers.yahoo.com/question/in...2114157AAtZGCd

So possibly just a neurologist.


All the best,
Youssarian