I believe the item you are thinking about is this, but I'm not positive. Have at it.
http://scienceblog.com/44329/making-temporary-changes-to-brain-could-speed-up-learning/

Hello.

I've been reading Slashdot for years, have never posted or modded anything and I would mod you up but I don't know how to do so yet. Anyways, I just wanted to say that I thoroughly agree with the thought behind this statement. I would write more but I'm tired and going back to sleep.

Good post sir.