People in "persistent vegetative states" given the ability to communicate

Very interesting. An excerpt:

The team used the fMRI scanner to measure the patient’s brain response while asking him questions. Brain signals associated with “yes” and “no” are complex and quite similar, and to overcome this problem the researchers asked the patient to imagine playing tennis for “yes” and walking through his home for “no”. Tennis movements activate regions at the top of the brain associated with spatial activities, while moving around the home is a navigational task that activates areas in the base of the brain. Using this technique the patient was able to correctly answer six test questions.