Scientists at the University of California at San Francisco (USCF) have taken another step towards translating brain activity into words, which would allow patients who can no longer speak to communicate again.
Many diseases can deprive patients of speech, despite intact brain capacity. To help them, researchers have been working for years on a “speech decoder” that would translate thoughts into words thanks to a computer connected to the brain implants.
Translating thoughts into words
“Ten years after the first decoding of speech from signals in the human brain, the accuracy, and speed of artificial speech is still much lower than that of natural speech,” said Joseph Makin, David Moses, and Edward Chang of the University of California at San Francisco (USCF). Their work, which is presented in Nature Neuroscience magazine, aims to make the process more fluid. Thanks to the new artificial intelligence (AI) system they have developed, the cortical activity in the brain can now be decoded in real-time and with an accuracy of 97%. “The average word error rate is no more than 3%”, scientists congratulate themselves. “We haven’t reached that point yet, but we think it could be the basis for a speech prosthesis,” says Dr. Joseph Makin.
To achieve these results, his team recruited four Americans and then equipped them with brain implants originally designed to monitor epileptic seizures. The patients then repeated a series of 30 to 50 sentences with up to 250 different words out loud for about 40 minutes. The data collected for each sentence was entered into a machine learning algorithm, which converted them into a series of numbers, which in turn were converted into English phrases.
Eventually, some of them will be used to equip healthy people with this type of brain implant. Elon Musk has invested $150 million to develop his neuralink device for this purpose, while the European Commission is funding the BrainCom project.