BCI lets completely “locked-in” man communicate with his son, ask for a beer

A German man in a locked-in state was fitted with a BCI system that relied on sound feedback. The man was able to change his brain activity in response to the feedback. He was able to ask for a beer, for his caretakers to play his favorite rock band, and for him to communicate with his son, according to a recent paper.

BCIs record the electrical activity of brain cells and translate those signals into action. Such systems usually involve a computer to translate signals from one source to another. BCIs can be placed on the head with a cap, or they can be placed directly into the brain. The former method is less intrusive but can be less accurate because of noise and brain surgery. It is an acceptable risk for many paralyzed or locked-in patients.

There were two significant milestone on the BCI front last year. In March 2021, we reported on Neuralink's demonstration of a monkey playing a game with a brain implant. The company was able to get the device to communicate with each other. The BrainGate Consortium successfully demonstrated a high-bandwidth wireless BCI in two human subjects.

This study used a wired BCI. People who have amyotrophic lateral sclerosis, also known as Lou Gehrig's disease, are often paralyzed and unable to communicate. BCIs that rely on eye movement have been developed to help restore communication ability. Patients in locked-in states have lost a small amount of motor control. The first successful demonstration of BCI-assisted communication in a locked-in patient was documented in this study.

The German man in the study was diagnosed with progressive muscle atrophy in August of 2015. He was not able to walk or talk for a few months, and by July 2016 he was artificially ventilated and fed through a tube. The man's condition deteriorated after he initially communicated via an device.

Realizing that it was a matter of time before he completely lost control of his eye movement, the man's family asked the co-authors of the book about it. The man began using an external BCI system that allowed him to select letters to form words and sentences. When the man became completely locked in, even this would not be enough.

The best option was an implanted BCI, which was performed in March 2019. They placed two microelectrode array in the patient's left motor cortex to detect neural signals, which could be sent via a wired connection to a computer for processing. The data would be decode and played back as feedback tones. The patient was able to change his neural firing rate to match the feedback after learning how to modify his sound tone. The man was able to select letters and spell words after many months of training.

Thanks to the rest of the team, the first message was a simple one. The man requested a head massage and a higher head position when visitors were present, as well as more gel on his eye, which was prone to dryness. Suggestions were made for improving the spelling system.

He could make specific requests for his feeding tube, such as soup with meat, sweet pea soup, and curry with potato. He requested a beer and for his caretakers to play his favorite band, Tool, very loud. Despite the detached academic tone of the paper, the communications with his young son tug at the heartstrings.

ich liebe meinen coolen (son’s name) – ‘I love my cool son’ on day 251; ‘(son’s name) willst du mit mir bald disneys robin hood anschauen’- ‘Do you want to watch Disney’s Robin Hood with me’ on day 253; ‘alles von den dino ryders und brax autobahnund alle aufziehautos’ – ‘everything from dino riders and brax and cars’ on day 309; ‘(son’s name) moechtest du mit mir disneys die hexe und der zauberer anschauen auf amazon’ – ‘would you like to watch Disney’s witch and wizard with me on amazon’ on day 461; ‘mein groesster wunsch ist eine neue bett und das ich morgen mitkommen darf zum grillen’ – ‘My biggest wish is a new bed and that tomorrow I come with you for barbecue’ on day 462.

The authors acknowledge that the communication rates for their system were much lower than measured in other studies involving patients who were not locked in, and they will continue to refine and improve their system. I don't think this German man and his family mind too much since they have been given the gift of reconnection by the authors.

Nature Communications was published in 2022. About DOIs is 10.1038/s41467-022-28859-8.

The image is from the Wyss Center for Bio and Neuroscience.