‘Exhilarating’ implant turns thoughts to speech

Scientists have developed a brain implant that can read people’s minds and turn their thoughts to speech.

The team at the University of California, San Francisco says the technology is “exhilarating”.

They add that their findings, published in the journal Nature, could help people when disease robs them of their ability to talk.

Experts said the findings were compelling and offered hope of restoring speech.

The mind-reading technology works in two stages.

First an electrode is implanted in the brain to pick up the electrical signals that manoeuvre the lips, tongue, voice box and jaw.

Then powerful computing is used to simulate how the movements in the mouth and throat would form different sounds.

This results in synthesised speech coming out of a “virtual vocal tract”.

You might think it would be easier to scour the brain for the pattern of electrical signals that code for each word.

However, attempts to do so have only had limited success.

Instead it was focusing on the shape of the mouth and the sounds it would produce that allowed the scientists to achieve a world first.

One of the researchers, said: “For the first time, this study demonstrates that we can generate entire spoken sentences based on an individual’s brain activity.

“This is an exhilarating proof of principle that, with technology that is already within reach, we should be able to build a device that is clinically viable in patients with speech loss.”

In experiments with five people, who read hundreds of sentences, listeners were able to discern what was being spoken up to 70% of the time when they were given a list of words to choose from.

Many diseases can lead to the loss of speech including:

Motor neurone disease

Brain injuries

Throat cancer

Some strokes

Neurodegenerative diseases such as Parkinson’s and multiple sclerosis

The team says it could work in some of these diseases.

However, the technology relies on the parts of the brain which control the lips, tongue, voice box and jaw working correctly. So patients with some types of stroke would not be able to benefit.

There is also the more distant prospect of helping people who have never spoken, including some children with cerebral palsy, to learn to speak with such a device, say the researchers.

Prof said: “We and others actually have tried to look at whether it’s actually possible to decode just thoughts alone.

It added: “We can hope that individuals with speech impairments will regain the ability to freely speak their minds and reconnect with the world around them.”

“This is very interesting work from a great lab but it must be noted that it is at very early stages and is not close to clinical applications yet.”

 

Lara Khouli