Researchers have successful help a paralysed man to communicate in full sentences with the aid of chip implanted in his brain.
It is the first time a completely locked-in person – someone who is conscious and cognitively able but fully paralysed – was able to communicate in full sentences, according to a study published in the journal Nature Communications this week.
“People have really doubted whether this was even feasible,” Mariska Vansteensel, a researcher at the University Medical Center Utrecht who was not involved in the study, told Science.org.
In 2015, the undisclosed German man, 36, was diagnosed with Amyotrophic Lateral Sclerosis (ALS), a rare progressive nervous system disease that leads to the loss of muscle control.
When an ALS patient can no longer speak, they can use an eye-tracking device to select letters on a screen. Later in the disease’s progression, they can answer yes or no questions with subtle eye movements.
Researchers implanted two microchips, each measuring about 1.5mm across, in the patient’s motor cortex – the region at the top of the human brain that is responsible for controlling movement.
They then trained the man to imagine physical movements. They were taking this step to try and get a reliable signal from the brain. They would then try to translate this signal into some sort of a command. This had been successful in previous studies but not this time.
Within two days, the man learned to control the frequency of the tone, researchers said.
Before his condition progressed, family members would hold up a grid of letters against a background of four colours. Family members would point to each colour section and row, and interpret any eye movement as a “yes”.
The researchers introduced a software to mimic this technique. The man would hear the words of a colour. For example “yellow” or “blue” to pick a block of letters from which to select.
He would then be played individual letters and use a rising or descending tone to either select or dismiss each. This way the man learned to communicate entire sentences, the researchers said.
It take him less than four minutes for the man to select letters to form a sentence.
“Many times, I was with him until midnight, or past midnight,” said Chaudhary. “The last word was always ‘beer’.”
The work has been praised by researchers as " remarkable", among which is Jaimie Henderson, a neurosurgeon at Stanford University who was not involved in the work.
“To me that’s a tremendous breakthrough and obviously quite meaningful for the research participant,” Henderson was quoted as saying.
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