A speechless person learns to communicate – look
The now 37-year-old man lost his speech as a result of the incurable nerve disease ALS (amyotrophic lateral sclerosis). In his right mind, he was trapped in his waking mind. Patients like him in the so-called “completely locked-in” stage no longer have any control over their eye movements, which is why other communication aids fail. Because one is to record the eye movement with cameras and to translate this into speech with a possibility. Such a system was used by the famous physicist Stephen Hawking.
Now an international research team, co-led by Jonas Zimmermann from the Wyss Center of Bio‐ and Neuroengineering in Geneva, reports that the study participant learned to communicate with a so-called brain-computer interface (BCI) at sentence level. Invasive BCIs are small devices surgically implanted in the brain that use electrodes to record brain waves and convert them into control signals.
As the researchers write in the study published on Tuesday, the patient was able to express his needs after around a hundred days. On day 251, for example, he asks his son if he wants to watch the Disney film Robin Hood with him.
To form words and sentences, the computer learns to associate “yes” and “no” with the firing rates of neurons in the brain’s motor cortex. By having a program read aloud letters, the study participant could say yes or no to using that letter. In this way he managed to form an average of one character per minute.
The case study provides evidence that willful communication is possible even for people who are completely mentally isolated, the researchers conclude.
However, Zimmermann dampens expectations: “It is a proof of concept with a single patient,” says the scientific director of the project in an interview with the Keystone-SDA news agency. The aim is to start a clinical study with more patients, for which new electrode implants are currently being developed that would fully integrate. The safety of such an implant is to be tested in preclinical animal studies.
The IST used by the ALS study participant is connected to the computer via a plug and cable. “The plug poses a risk of infection because the wound has to remain open all the time,” says Zimmermann.
In the not too distant future, brain-computer interfaces could help many ALS patients. This opinion is Anne-Lise Giraud Mamessier. The neuroscientist, who works at the University of Geneva and the Institut de l’Audition in Paris, was not involved in the study. Until then, however, a number of technological hurdles and those for better decoding of language intentions have to be overcome.
There is also a difficulty in generating numerous successful proofs of concept to convince patients to undergo brain surgery. She also emphasizes the importance of the electrodes. “They should be as safe as possible and have a very low probability of infection and brain damage,” says Giraud Mamessier.
In addition to Jonas Zimmermann, the German brain researchers Niels Birbaumer and Ujwal Chaudhary are among the study leaders. Birbaumer and Chaudhary published a study back in 2017, on the basis of which four ALS patients communicated using a hood equipped with sensors. However, the study had significant shortcomings, and the journal “Plos Biology” finally withdrew it. The researchers were accused of massive scientific misconduct that has not yet been refuted.
The German Research Foundation (DFG) excluded Birbaumer for five years, and Chaudhary for three years, from any review activity and eligibility for applications. While Chaudhary accepted the death, Birbaumer filed a lawsuit against it in 2020. The legal process is about to be completed, and the DFG will inform you shortly about the outcome.
Adopted by Springer Nature, which published the current work, the scientific reviewers of the studies are alert to controversies in each subject. Once they went ahead. For reasons of confidentiality, however, one cannot comment on the editorial development of individual contributions, a spokeswoman wrote on request.
The neuroscientist Giraud Mamessier points out that other studies have shown that it is possible to decode binary decisions – i.e. “yes” and “no” statements. The “episode” that happened did not change her opinion of Birbaumer’s research, nor did her opinion of his “sincere desire to find solutions to improve the quality of life of locked-in patients”. They considered the results of the present study to be “very plausible”.
https://www.nature.com/articles/s41467-022-28859-8
(SDA)