Researchers have been able to reconstruct words based on the brain waves of patients thinking those words, using computer modelling technology.

They were able to do it by gathering the electrical signals directly from the patients' brains, and a computer model was used to reconstruct the sounds of words that the patients were thinking of, the BBC reported.

The system is seen as a future way to help comatose and locked-in patients to communicate. To do the tests the researchers implanted electrodes directly into the same part of participants' brains.

The work was led by Brian Pasley of the University of California, Berkeley. Pasley and his team of researchers focused on an area of the brain called the superior temporal gyrus, or STG.

This region of the brain is part of the hearing apparatus and also one of the "higher-order" brain regions which help us make linguistic sense of the sounds we hear.

Pasley and his team monitored the STG brain waves of 15 patients who were undergoing surgery for epilepsy or tumours, while at the same time also playing audio of a number of different speakers reciting words and sentences.

The team then used computer modelling to map out which parts of the brain were generating which brain waves in response to the different frequencies of sound being played.

Using this model patients were then presented with words to think about, and the team were then able to guess which word the participants had chosen. And using the computer model they were also able to reconstruct some of the words by converting the brain waves back into sound.

More details on the research can be found in the Public Library of Science here