Think of a lemon

From Mind Hacks via BoingBoing:  This should get the biofeedback nerds out there going "squee!".  Imagine you're completely paralysed. How the hell do you communicate?  No blinking in Morse for you, that's too easy.  Well...

"A recent article in New Scientist describes a 46-year-old woman who was totally locked-in. Her doctor, Dr. Birbaumer, wanted to ask her if she'd like to have electrodes implanted in her brain to help her communicate, but they couldn't figure out a way for the woman to answer.

"[W]alking past an electronics store one day, Birbaumer's colleague Barbara Wilhelm spotted a medical device for measuring the pH of saliva, and had an idea. They trained the woman to change the acidity of her spit by imagining either the taste of lemon, or the taste of milk. She learned to push the pH one way to say "yes", the other to say "no"."

How cool is that?