In a meeting with the man in February 2018, Chaudhary tried to automate the communication system that the family was already using. The team connected an eye-tracking device to computer software that would read colors and line numbers, allowing a man to select letters one at a time using his eye movements to spell words.
But as the man lost more and more control over his eye movements, he became less able to communicate using the device. “We proposed transplantation [an electrode]Says Chaudhary. Small electrodes can be implanted in the brain to directly record the electrical activity of brain cells. The procedure જેમાં which involves drilling a hole in the skull and cutting off the protective layers of the brain તે comes with a small risk of infection and brain damage. So that was the last resort, says Birbaumer. “If [non-invasive] BCIs and i-trackers no longer work, there is no other option, ”he says.
Chaudhary says the man consented to the procedure using eye movements. His wife and sister also agreed. By the time the procedure was approved by the Ethics Committee and the German Federal Institute for Drugs and Medical Devices in late 2019, the person had lost the ability to use the eye-tracking device. In March 2019, surgeons implanted two small electrode grids, around 1.5 millimeters each, in the human motor cortex – an area at the top of the brain that is responsible for controlling movement.
Turn signals into commands
The day after the electrode was implanted, the team began trying to help the man communicate. Initially, the man was asked to conceive of bodily movements – this has helped other recipients to control prostheses and exoskeletons, and Elon Musk’s company Neuralink plans to adopt this approach. The idea is to get a reliable signal from the brain and translate it into some kind of command.
But the team could not bring him to work. After 12 weeks of trying, they rejected the idea and decided to try an approach called Neurofeedback instead. Neurofeedback works by showing a person’s brain activity in real time so they can learn how to control it. In this case, when the electrodes in the human brain notice an increase in activity, the computer will play an increasing audio tone. A decrease in brain activity will play a descending tone.
“In two days, he was able to increase and decrease the frequency of sounds,” says Choudhury, who says he used to visit the man at his home every week during 2019 until the coronavirus hit. “It was just incredible.” Man eventually learned to control his brain activity so that he could play a rising vowel to indicate “yes” and a descending vowel to indicate “no”.
The team then introduced software that mimicked a paper-based computer system that the man originally used to communicate with his family. The man will hear the word “yellow” or “blue”, for example, to choose a block of letters to choose from. It will then be played with individual characters and the ascending or descending tones will be used to select or delete each (see video).
In this way, man was soon able to communicate complete sentences. ,[His family] I was very excited to hear what he had to say, “said Chaudhry, who along with his colleagues published his findings in the journal. Nature Communications On tuesday. The translation of one of the first sentences spelled by the man was “Boys, it works very easily.”
Communication was still slow – it takes about a minute to select each character. But researchers believe the device has significantly improved man’s quality of life. He has asked for specific meals and soups, instructed caregivers on how to move and massage his feet, and, for example, asked to watch movies with his young son. Translation of a sentence “I love my cool son.”
“Often, I was with him until midnight or until midnight,” says Chaudhary. “The last word was always ‘beer’.”
The translation of one of the first sentences spelled by the man was “Boys, it works very easily.”
Choudhury envisions developing a list of frequently used words that could eventually allow the software to autocomplete with the spelling of human words, for example. “There are many ways we can make it faster,” he says.
No one knows how long the electrodes will last in the human brain, but other studies have shown that the same electrodes continue to function five years after being implanted in others. But for a locked-in person, “one day can make a difference,” says Kianush Nazarpor of the University of Edinburgh, who was not involved. “It’s a basic opportunity for them to regain control of their lives,” he says. “A high quality day can be really important for that person.”
Nazarpore thinks the technology could be regularly offered to similarly locked-in individuals over the next 10 to 15 years. “For a person who has no communication at all,” yes “/” no “is also potentially life-changing,” he says.
Brian Dickey, director of research development at the Motor Neuron Disease Association in the UK, agrees that the timeline is realistic. But it is amazing how many people with motor neurone disease – of which ALS is the most common type – stand to benefit from such BCIs.
A person receiving BCI has a form of ALS called progressive muscular atrophy (PMA). This form of the disease targets the motor nerves that travel from the spine to the muscles, leaving people unable to control their muscles. But about 95% of ALS cases also involve degeneration of the motor cortex in the brain, says Dickey.