Imagine being able to read other people’s thoughts, to hear their inner dialogue. It’s a fantasy that has inspired superhero comic books, movies and science fiction novels, but so far scientists have been unable to prove that such psychic or telepathic powers really exist. Or at least, they have yet to prove that humans are capable of them. Machines are another story. In fact, scientists are currently on the verge of inventing a telepathic machine that can read your mind just by looking at a scan of your brainwaves, then repeat back to you in an electronic voice exactly what you were thinking, according to a report by New Scientist. The technology could be a breakthrough for people like Stephen Hawking, who suffers from Lou Gehrig’s disease, or people made mute through paralysis or locked-in syndrome, since it can translate the brain waves that we create when we think something into speech. Of course, some others may also be concerned that the technology could one day be used to make our private thoughts not-so-private anymore. Here’s how it works. A team of researchers led by Brian Pasley by the University of California at Berkeley first pinpointed key areas in the brain where speech and sound is processed and generated. They then studied the way that certain neurons are uniquely triggered depending on the frequency of the sound that is heard. “Simply put, one spot [of neurons] might only care about a frequency range of 1000 hertz and doesn’t care about anything else. Another spot might care about a frequency of 5000 hertz,” said Pasley. “We can look at their activity and identify what frequency they care about. From that we can assume that when that spot’s activity is increasing there was a sound that had that frequency in it.” Because they were interested in reconstructing speech sounds specifically, such as spoken words and sentences, the researchers didn’t just study the neural activity of sound frequency. They also considered other important aspects of speech sounds such as the rhythm of syllables and fluctuations of frequencies. They were then able to train an algorithm to interpret the neural activity and then ‘translate’ that neural activity back into the sound that was originally heard. The reason this makes the machine telepathic is that brain activity is believed to be virtually the same whether we hear a sentence or whether we think it. In other words, the algorithm can turn even your inner thoughts into spoken speech using exactly the same method. So far tests on the machine have revealed rudimentary, but promising, results. While the concept behind the machine and the algorithm is fairly basic, real thoughts are extremely complex neurological entities, and will take a lot more effort to fully ‘decode’ into audible speech.