Reading Your Brain's Signals!

Feb 11, 2012 By Deepa Gopal
Deepa Gopal's picture

Mind-reading. Sounds far-fetched? Well, it may become a reality soon if researchers at the University of California, Berkeley are to be believed. In a breakthrough study, scientists have demonstrated a way to read a person's mind by translating brain waves into words! 

Before you worry about how this can be used by people intending harm, scientists assure us that the biggest use for this medical technology would be in helping patients suffering from stroke or paralysis communicate. 

Words to Wires!

Our brain in its simplest form can be thought of as a set of wires which carry electrical signals. So, the sound has to be converted into electrical signals.

How does that happen? When we hear words, they pass through our ears and hit a membrane -- basilar membrane, in the inner ear or Cochlea. This membrane breaks up the sounds into different frequencies and each section of this membrane vibrates differently. These are picked up by the neurons that are part of our brain's nervous system -- generating specific electric signals. These electric impulses then go into different parts of the brain where the language is processed.

Similarly, the act of speaking also produces a distinct brain activity. By deciphering these signals, researchers believe it may be possible to know what a person is hearing or intends to say simply by monitoring brain activity. Amazing, isn't it! So, how did the scientists go about the experiment?

The Experiment

The researchers enlisted the help of 15 patients who were undergoing surgery for the treatment of severe epilepsy (or seizures). The patients had part of their skull removed so that electrodes (devices that monitor electrical activity) could be placed directly on the cortex or surface of the brain to find out the source of their seizures. Aside from epilepsy, the patients were essentially healthy and had normal hearing and speech. 

The patients listened to 5-10 minutes of audio of different words and sentences, and their brain activity was recorded. Scientists were able to match sounds to specific brain patterns. Next, they tried the opposite -- capturing brain activity and converting back to sound. The model could figure out the sounds, though the exact words were not known -- and scientists had to string together sounds to guess the word. 

Brian Paisley, the lead scientist compares his experiment to a piano player who can look at the keys being played at a piano concert on TV, and imagine the song! 

While a lot more needs to be done, this is a first step in helping those needing a voice.

Courtesy BBC, Newscientist