A fully paralyzed man with ALS, or amyotrophic lateral sclerosis, was able to communicate with doctors and his family using a brain-computer interface that allowed him to spell out words using his thoughts, according to a new study published in Nature Communications.
This research represents the first time a completely paralyzed person regained the ability to communicate at length, explains study author Niels Birbaumer, a former neuroscientist at the University of Tübingen, to the New York Times’ Jonathan Moens.
The patient had previously used eye-tracking technology to talk with family before losing control of eye movements, but began working with researchers while he could still talk using that method.
After implanting the patient’s brain with microelectrodes, researchers tried for 86 days to communicate until they decided to try a method called auditory neurofeedback, writes Technology Networks’ Ruairi J Mackenzie.
The process involved researchers showing the patient his brain activity in real time, and the patient learning to change his brain signals, writes Science’s Kelly Servick. The man learned to hit audible target notes by increasing or decreasing his neural activity. A higher tone—increased firing rate of neurons—meant “yes,” while a lower tone meant “no.”
The patient spelled words out slowly, at about one letter per minute, per the study. On the second day he was spelling freely, his first message thanked the research team. He wrote: “erst mal moechte ich mich niels und seine birbaumer bedanken,” or “first I would like to thank Niels and his birbaumer,” according to the paper. (Birbaumer is the lead author's last name, and many of the patient's initial messages contained some spelling and grammar errors at first.)
The patient made requests regarding his care, including the positioning of his head, and also asked his 4-year-old son whether he wanted to watch Disney’s Robin Hood with him.
"For his family and for everybody on the team, it was very emotional as well as satisfying that we enabled someone to express themselves and to express their wishes and desires," study author Ujwal Chaudhary, ALSVoice co-founder and former neuroscience researcher at the University of Tübingen, told As It Happens’ Gillian Findlay. "This was, I would say, very fulfilling as a researcher and also as a human being."
Out of 107 days that the man spelled words, he produced intelligible output on 44 days, according to the study.
Chaudhary and Birbaumer conducted similar research in 2017 and 2019, but the studies were retracted after a German Research Foundation investigation found that the researchers provided false information.
“This work, like other work by Birbaumer, should be taken with a massive mountain of salt given his history,” Brendan Allison, a neuroscience researcher at University of California San Diego who was not involved in the study, tells the Times.
But Natalie Mrachacz-Kersting, a brain-computer interface researcher at the University of Freiburg in Germany not involved in the research, tells the newspaper it’s “a solid study.”
Birbaumer tells Technology Networks that the new study “shows that all accusations are wrong,” and that legal action would exonerate their previous research.
The authors conclude that “this case study has demonstrated that a patient without any stable and reliable means of eye-movement control or identifiable communication route employed a neurofeedback strategy to modulate the firing rates of neurons in a paradigm allowing him to select letters to form words and sentences to express his desires and experiences.”