The 37-year-old lost his speech as a result of ALS (amyotrophic lateral sclerosis). In his right mind, he was trapped in his waking mind. Also, patients like him in the so-called “total closure” stage no longer have any control over their eye movements, which is why other means of communication have failed. Because one possibility is to record eye movements with cameras and translate them into speech using software. Such a system was used by the famous physicist Stephen Hawking.
Now, an international research team, co-led by Jonas Zimmermann of the Wyss Center for Bioengineering and Neuroscience in Geneva, reports that a study participant learned to communicate with a so-called brain-computer interface (BCI) at the sentence level. Invasive BCIs are small devices that are surgically implanted in the brain and use electrodes to record brain waves and convert them into control signals.
As the researchers wrote in the study published on Tuesday, the patient was able to express his or her needs after about a hundred days. For example, on day 251 he asked his son if he would like to watch the Disney movie Robin Hood with him.
How hard is it to fire neurons
To form words and sentences, the computer learns to map “yes” and “no” to the firing rates of neurons in the brain’s motor cortex. By having the program read the letters out loud, the study participant can say yes or no to using that letter. This way he was able to make an average of one character per minute.
The researchers conclude that the case study provides evidence that intentional communication is possible even for completely mentally isolated people.
However, Zimmerman dampens expectations: “It’s proof of concept with one patient,” says the project’s scientific director in an interview with Keystone-SDA news agency. The goal is to start a clinical study with more patients, as new electrode implants that will fully grow are currently being developed. The safety of such an implant should be tested in preclinical studies in animals.
The person used in the ALS study is connected to the computer with a socket and cable. “The tampon poses a risk of infection because the wound has to remain open all the time,” Zimmerman says.
Hope for the not too distant future
In the not-too-distant future, brain-computer interfaces could help many ALS patients. This is the view of Anne-Lise Giraud Mamissier. The neuroscientist, who works at the University of Geneva and the Institute for Testing in Paris, was not involved in the study. Until then, however, a number of technological and one-to-one hurdles must be overcome to better decode linguistic intents.
There is also difficulty in obtaining sufficient successful proof of concept to persuade patients to undergo brain surgery. It also emphasizes the importance of electrodes. “They have to be as safe as possible and have a very low chance of getting infection and brain damage,” says Gero Mamissiere.
Fuss about the previous study
In addition to Jonas Zimmermann, German brain researchers Niels Bierbaumer and Ujwal Choudhury were among the study leaders. Bierbaumer and Choudhury already published a study in 2017, according to which four ALS patients learned to communicate — with the help of a sensor-equipped cap. However, the study had significant shortcomings, and it was finally pulled by the journal PLoS Biology. Researchers have been accused of serious scientific misconduct that has yet to be refuted.
The German Research Foundation (DFG) has disqualified Bierbaumer for five years, and Choudary for three years, from any review activity and eligibility for applications. While Chaudhary agreed, Bierbaumer filed a lawsuit against him in 2020. The legal process is nearing completion, and the DFG has announced upon request that it will be possible to provide information about the outcome soon.
Very reasonable results
According to publishers Springer Nature, which published the current work, scientific reviewers of studies are alert to controversies on each topic. They proceeded accordingly carefully. For reasons of confidentiality, a spokeswoman wrote on request, the editorial career of individual contributions could not be commented on.
Neuroscientist Jerrod Mamissier notes that other studies have shown that it is possible to decode binary decisions — that is, “yes” and “no” statements. The “episode” that occurred did not change her opinion of Bierbaumer’s research, nor her opinion of his “sincere desire to find solutions to improve the quality of life of incarcerated patients”. She considers the results of the current study “highly plausible.”