Brain breakthrough that could help Stephen Hawking speak again

Scientists are investigating the use of brain waves to create a new form of communication which could return the power of speech to paralysis sufferers like Physicist Stepehen hawking.

Diagnosed with Lou Gehrig's disease at 21, Hawking, now 70, relies on a computerised device to speak.

The new research could pave way for prosthetic devices in the brain returning the power of speech to those paralysed by injury or disease.

Researchers followed 11 epilepsy patients who had electrodes implanted in their brains to pinpoint the origin of their seizures, with neuron activity as they uttered one of five vowels or syllables containing the vowels recorded.

They found two areas, the superior temporal gyrus and a region in the medial frontal lobe, that housed neurons related to speech and attuned to vowels.

Neurons in the superior temporal gyrus, responsible for processing sounds responded to all the vowels, whereas those that fired exclusively for only one or two vowels were found in the medial frontal region involved in memory.

The unravelling of vowels in the superior temporal gyrus reflected the anatomy that made speech possible, specifically the tongue's position inside the mouth, the Nature Communications study says.

"We know that brain cells fire in a predictable way before we move our bodies." Dr Itzhak Fried, of the University of California Los Angeles, said.

"We hypothesised that neurons would also react differently when we pronounce specific sounds. If so, we may one day be able to decode these unique patterns of activity in the brain and translate them into speech," Fried said.

"Once we understand the neuronal code underlying speech, we can work backwards from brain-cell activity to decipher speech. This suggests an exciting possibility for people who are physically unable to speak," said Fried.