A doctor sits in front of a screen, analyzing and recording the neurons firing as you lay asleep, dreaming, electrodes implanted in your brain. He can tell exactly what you're dreaming about. Reality? Not quite yet.
Dr. Moran Cerf is in the process of collecting a neuron-thought database from his patients (volunteers, who do actually have electrodes implanted for treating brain seizures). Each dream is like an electronic record, with each neuron associated with specific thoughts or ideas. If a large enough database can be amassed, he and his colleagues hope to be able to "read minds" just by examining which neurons fire over the course of a dream.
This technology could eventually be used for the benefit of mankind, to help people who are in a coma or have locked-in syndrome communicate (not just in Inception-esque scenarios). It could also be used for thought-controlled machines in the more distant future. Unfortunately, this electronic, mind-reading brain scanner probably won't exist for a while. [BBC News via Popular Science]