Computers may soon be able to read minds

Mind reading devices are no longer confined to the world of science fiction. Scientists at the University of California at Berkeley have developed a computer program that can identify the words a person is thinking. When someone hears speech, the sound waves activate sensory neurons, or nerve cells, in the inner ear which then send the information to areas of the brain where it is interpreted as words. The researchers recorded the brain activity of seven volunteer subjects while they read aloud text displayed on a computer screen.

The researchers used this information to map out the neurons in each subject’s brain that reacted to various aspects of the words heard and then developed an individualized decoder showing which neurons were stimulated by which sound waves for each subject.

The volunteers then read the same text silently while the researchers used the decoder to interpret brain activity. The decoder accurately identified which words several of the volunteers were thinking.

One day, the technology may be used to enable people who cannot speak to communicate with the outside world, but the researchers admit the study provides only preliminary data and there is much work to be done yet. To assist people who are unable to speak, the decoder would have to be developed based on what the person hears, not on self-generated speech. The data needs to be fine-tuned by analyzing brain activity associated with different rates of speaking and different pronunciations of the same word.

“Ultimately, if we understand covert speech well enough, we’ll be able to create a medical prosthesis that could help someone who is paralyzed, or locked in and can’t speak,” Brian Pasley, research scientist at UC Berkeley told New Scientist magazine.

Several other studies have investigated technological mind-reading methods, like using brain activity to detect what pictures a person is looking at or to identify the brain location activated when a person thinks about specific concepts.

Three years ago, another Berkeley research team succeeded in decoding brain signals generated while a person watched moving images. In that study, the researchers used an MRI scanner to record brain activity while the subjects watched Hollywood movie trailers. The information was fed into a computer program that associated visual patterns in the movie with the corresponding brain activity. In the final analysis, the computer was able to use brain activity information to produce a blurry but continuous reconstruction of the movie the subject had watched.

So far, the technology can only reconstruct movie clips the subjects have viewed but the researchers believe one day it may be possible to reproduce internal imagery such as dreams and memories.

“We are opening a window into the movies in our minds,” said professor Jack Gallant, a UC Berkeley neuroscientist and study coauthor.

The researchers hope some day the technology can be used to provide a better understanding of what goes on in the mind of someone who cannot communicate verbally, like a stroke or coma patient or someone with a neuro-degenerative disorder.

But they caution it may be decades before scientists can put together all of these technologies to create one multi-sensor, mind-reading device that can interpret thoughts and intentions.