A pair of brain microchips could one day allow those in 'pseudocomas' to communicate whatever they want, a new breakthrough suggests.
first, a 34-year-old patient who lacked even the most subtle of muscle
twitches has used the technology to share a few precious words with his
family, using little more than an intent to move his eyes.
Similar devices have previously given patients with the fast-progressing condition amyotrophic lateral sclerosis (ALS)
the means to send simple messages with extremely limited movements, but
researchers say the severity of the man's condition here represents a
significant advancement for the technology.
knowledge, ours is the first study to achieve communication by someone
who has no remaining voluntary movement and hence for whom the BCI is
now the sole means of communication," says neuroscientist Jonas Zimmermann from the Wyss Center in Switzerland.
pseudocoma is also known as 'locked-in' syndrome, because while these
patients cannot walk or talk, they are still very much conscious,
capable of seeing, hearing, tasting, smelling, thinking, and feeling.
the ability to move the mouth or the tongue, however, communication is
severely limited. If the eyes can still move, patients can sometimes
blink or 'point' with their pupils to make themselves understood, but in
some advanced cases, even that basic form of communication is out of
in this case was one such patient. Within months of diagnosis with the
condition, he had already lost the ability to walk and talk. A year
later, the patient was placed on a ventilator to help him breathe. A
year after that, he lost the ability to fix his gaze.
The extreme isolation ultimately led the patient and his family to agree to a cutting-edge experiment.
the patient lost the ability to move his eyes, he consented to a
surgical procedure that would implant two microchips into the part of
his brain that controls muscle movement.
was equipped with 64 needle-like electrodes, which could pick up on his
conscious attempts to move. That brain activity was then sent to a
computer, which translated the impulses into a 'yes' or 'no' signal.
In the past, similar brain implants have allowed some patients with ALS to communicate via a computer typing program.
But this is the first time an ALS patient without the ability to so
much as use their eyes has been able to do something similar.
have really doubted whether this was even feasible," Mariska
Vansteensel, a brain-computer interface researcher who was not involved
in the study, told Science.
(Chaudhary et al., Nature Communications, 2022)
Above: The experimental setup of the brain implants, plus the biofeedback device and the spelling program.
technique took months of training, but once the patient learned how to
control the firing rates of his brain signals, he was able to respond to
a spelling program and select specific letters, spoken out loud by the
program, to form words and even sentences.
letter the patient heard took about a minute for the patient to respond
to, making for slow progress, but nonetheless, for the first time in a
long time, the device allowed this man to express himself.
accuracy of the technology is still not perfect. The patient could only
signal 'yes' or 'no' about 80 percent of the time, with about 80 percent
accuracy. Some days he could only generate words, not sentences.
apparent poor performances are primarily due to the completely auditory
nature of these systems, which are intrinsically slower than a system
based on visual feedback," the authors write in their study.
phrase the ALS patient successfully spelled out was a 'thank you' to
the lead neurobiologist on his case, Niels Birbaumer.
came a slew of requests for his care, like "Mom head massage" and "I
would like to listen to the album by Tool [a band] loud".
Then, 247 days after the surgical procedure, the patient gave his verdict on the device: "Boys, it works so effortlessly".
On day 251 he sent a message to his kid: "I love my cool son". He then asked his child to watch a Disney film with him.
462, the patient expressed that his "biggest wish is a new bed", and
that the next day he could go with his loved ones to a barbecue.
someone is forming sentences like this, I would say it is positive. Even
if it is not positive, it is not negative," first author of the study
Ujwal Chaudhary told The Guardian.
when I was there, he said, 'Thank you for everything, sister' [to his
sister, who helps care for him]. It was an emotional moment."
The ability for someone in a pseudocoma to communicate obviously comes with a whole slew of ethical considerations.
all, who condones the initial insertion? And once a person has learned
to communicate again, can they speak for themselves and the future of
their care? How accurate do these systems need to be before we can
adequately interpret what patients are telling us?
have rules or outlines for this type of technology quite yet, but if the
device turns out to be useful for other patients, we will need to start
confronting these quandaries.
advanced ALS patients their voices back could be a huge medical
breakthrough and a great relief for individuals and their families. How
we respond to those voices is up to us.
The study was published in Nature Communications.