Scientists can now "decode" people's thoughts without even touching their heads, The Scientist reported.
Past mind-reading techniques relied on implanting electrodes deep in peoples' brains. The new method relies on a noninvasive brain scanning technique called functional magnetic resonance imaging (fMRI). fMRI tracks the flow of oxygenated blood through the brain, and because active brain cells need more energy and oxygen, this information provides an indirect measure of brain activity.
By its nature, this scanning method cannot capture real-time brain activity, since the electrical signals released by brain cells move much more quickly than blood moves through the brain. But remarkably, the study authors found that they could still use this imperfect proxy measure to decode the semantic meaning of people's thoughts, although they couldn't produce word-for-word translations.