Brain's 'thesaurus' map can make 'mind-reading' reality

What if you could decode people's inner thoughts? A team of researchers has built a "semantic atlas" that shows in vivid colors and multiple dimensions how the human brain organizes language.

The atlas by the University of California scientists identifies brain areas that respond to words that have similar meanings.

The findings are based on a brain imaging study that recorded neural activity while study volunteers listened to stories from "The Moth Radio Hour." They show that at least 1/3 of the brain's cerebral cortex, including areas dedicated to high-level cognition, is involved in language processing.

Notably, the study found that different people share similar language maps.

"The similarity in semantic topography across different subjects is really surprising," said study lead author Alex Huth.

Detailed maps showing how the brain organizes different words by their meanings could eventually help give voice to those who cannot speak, such as people who have had a stroke, brain damage or motor neuron diseases such as ALS.

While mind-reading technology remains far off on the horizon, charting language organization in the brain brings decoding inner dialogue a step closer to reality, the researchers said.

"This discovery paves the way for brain-machine interfaces that can interpret the meaning of what people want to express," Huth said. "Imagine a brain-machine interface that doesn't just figure out what sounds you want to make, but what you want to say."

The study is published in the journal Nature.