Building the thought decoder began by developing an algorithm tailored to each individual subject. The participant was asked to read a passage, for instance John F. Kennedy's inaugural address, aloud to get a base reading. Then they were asked to read it to themselves. And finally, to just sit and do nothing. That allowed the team to isolate which neurons were firing when vocalizing the text. Then a visual representation of the sound waves is created and those sounds are matched with particular brain patterns. Then while the participants read silently to themselves the decoder is able to reconstruct the words based purely on what neurons are firing.

Of course, the technology is far from perfect. While the results were described as "significant" a reliable device that can translate thoughts in to words is a long way off. But the team from Berkeley is optimistic that one day they'll be able to give the gift of speech to someone who is paralyzed or "locked-in."

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