"Conversation with Comatose Patients": How Far Have We Come? Promising Research and Unavoidable Limitations

"No Response" Does Not Mean "Unconscious"? Patients Who Moved Sounds with Brainwaves

Calling their name by the bedside yields no response. Holding their hand, they do not squeeze back.

In such moments, the family desperately wants to know: Can their voice be heard? Do they know someone is there? Are they in pain?

What is happening inside people who can no longer respond due to severe brain injury? A study introduced by Germany's WELT seeks to answer this question.

A research team from Columbia University in the U.S. has developed a system that allows patients to manipulate electronic sounds using brainwaves recorded from the scalp. Some patients, who outwardly cannot respond to instructions, have managed to affect the outside world through brain activity.

However, it is premature to interpret this achievement as enabling free conversation with people in a coma. It is necessary to distinguish between the current findings of the study and future expectations.

Detecting the Intention to Move Even When Hands Cannot Move

The study was led by neurologist Jan Claassen and his team at Columbia University. The findings were published on October 22, 2026, in the neurology journal "Brain."

At the core of the system is the "Brain-Computer Interface," or BCI, which connects the brain to a computer.

In this method, brainwaves are recorded using electrodes attached to the scalp, eliminating the need for surgery to implant chips in the brain.

Patients listen to sounds and instructions through headphones. For example, they are asked to repeatedly try to open and close their right hand to speed up electronic sounds, and to stop doing so to slow them down.

Even if their hands do not actually move, the computer analyzes the brain activity when they attempt to move, linking it to changes in sound. Patients hear these changes.

The important point here is that it is not merely measuring the brain's response to hearing sounds. It is about altering brain activity according to instructions and connecting it to the operation of external devices.

However, the device does not read all of the patient's thoughts. It targets signals related to specific tasks, such as attempting to move a hand.

13 Out of 41 Patients Succeeded in Operation—What "About 1 in 3" Means

The study involved 41 patients with acute brain injuries who clinically showed no response. Of these, 13 patients, about 32%, succeeded in controlling the BCI.

In a separate test, 8 patients showed signs of consciousness retention, known as "Cognitive Motor Dissociation (CMD)."

CMD broadly refers to a state where brain activity in response to instructions is recognized, but it cannot be expressed as physical movement. Understanding and conveying through movement do not align.

This result highlights the difficulty of uniformly understanding unresponsive individuals based solely on appearance.

However, this does not mean that "1 in 3 comatose patients can definitely operate the device." The figures are based on the results of 41 patients examined at a single facility and cannot be directly applied to all patients with long-term consciousness disorders or different causes.

It Has Not Yet Been Possible to Convey "I'm in Pain" or "I Want to See My Family"

The central achievement demonstrated in this study is the manipulation of sound via brainwaves.

This is different from forming sentences of one's wishes or consistently answering doctors' questions. The paper positions this as a study first examining whether a one-way BCI can be controlled.

The goal of the research team is to enable patients to more directly convey states like "I am in pain" or "I am hungry" to doctors and family.

This distinction is not necessary to diminish hope but to accurately convey what is possible for patients and their families.

There are still challenges between changing electronic sounds and confirming intentions. Does the patient understand the question? Is the intended answer correctly outputted? Can they repeatedly answer the same question?

To use this as a communication tool in medical care, these aspects need to be verified.

Not Being Able to Operate Does Not Mean "No Consciousness"

There is another result that should not be overlooked.

Among 22 severely ill patients with known consciousness who participated for comparison, only 9 could control the BCI. Not all patients known to be conscious succeeded in this task.

Therefore, the reverse conclusion that "because they couldn't operate the device, they have no consciousness" cannot be drawn.

The study showed that patients who could operate the BCI tended to have better recovery later. However, this is a result of examining the correlation and does not prove that using the device itself caused recovery.

While it can be expected to support future medical care, this result alone cannot determine each individual's future.

What families most want to know is "what will happen to this person." Therefore, it is essential not to confuse the research results of the group with what can be understood about the individual in front of them.

Reactions on Social Media: Surprise and Questions About Practical Use

This study was shared on the overseas bulletin board-style SNS, Reddit.

In the science community "r/science," the results were received as very intriguing, with comments expressing surprise at future developments. On the other hand, there were posts expressing concerns about whether there would be time and systems to accommodate this technology in busy medical settings.

There were also voices suggesting that despite hearing about similar research before, it does not seem to be widely used outside of research.

These are the impressions of a limited number of posters and do not represent the entire public opinion. Additionally, criticisms of the medical field mentioned in the posts cannot be taken as facts.

Nevertheless, it is noteworthy that the discussion does not end with the novelty of the technology alone.

For the technology to reach patients, it is not enough for the device to work. Who prepares it, who interprets the results, and how it is reflected in daily care are crucial. The questions on SNS are directed at the gap between research achievements and actual medical practice.

Reader Comments Reflecting Memories as Family Members

Reader comments were also included in the user-provided WELT article text. These should be introduced separately from SNS posts.

In addition to voices welcoming the research, there were posts recounting memories as family members, such as speaking to an unresponsive grandmother and feeling a slight response in her hand.

Of course, it is not possible to determine the state of consciousness at that time or its commonality with the current research from individual experiences. Still, it conveys how significant even a slight response can be for families.

There were also readers questioning the accuracy of the term "coma" used in the article and those concerned about the suffering of people unable to convey their intentions.

These reactions reflect the expectations behind the research. What people desire is not just the success of machine operation but to know what the person feels and needs.

However, from the possibility that "consciousness may remain," it cannot be extrapolated to "understanding everything" or "always feeling pain." It is also important not to fill in unknown parts with just hope or fear.

What Needs to Be Considered in Japan Is How to Confirm the Patient's Voice

This research is not a distant matter for those facing family care or nursing in Japan.

Continuing to speak to someone who does not respond comes with anxiety. There is a simultaneous desire to believe the voice is reaching them and the feeling of not truly knowing.

The current achievement does not guarantee that "they are definitely hearing" for each patient. However, it shows the possibility that cannot be captured by externally observable responses alone.

If such technology advances towards practical use in the future, verification will be required to ensure it can be used with Japanese instructions, what kind of voice is easy for the person to understand, and how to confirm the obtained signals.

Moreover, caution is needed, especially when it seems like intentions are being read. A system is essential to prevent family members or medical personnel from accepting the desired answer as the patient's answer.

This is to avoid turning the surrounding wish of "wanting a response" into a definitive statement of "the patient desires this."

Small Changes in Sound as an Entryway to Dialogue

The value of this research lies not in the fact that conversation has already been completed.

It lies in showing the possibility that people who cannot use their voice or move their limbs can interact with the outside world through a different route.

For families, the wishes beyond that are concrete. Are they in pain? Do they want to rest? Do they want someone by their side? They want to ask the person and confirm the answer.

At present, there are still challenges to be verified before reaching that point. Nevertheless, the fact that brain activity changed sound instead of immobile hands is significant.

The absence of a response does not mean there is nothing to convey. Research is progressing to gradually bridge the gap between the two.

Sources and References

1. WELT: Referenced for the overview of the research and explanations from researchers.
   https://www.welt.de/gesundheit/article6ad9e950d76437b82f935370/koma-forscher-koennen-ploetzlich-mit-bewusstlosen-menschen-kommunizieren.html

2. Brain Published Paper: Primary source for the number of subjects, BCI tasks, success rates, comparison groups, and correlation with recovery. Published on October 22, 2026.
   https://doi.org/10.1093/brain/awag210
   Paper Title: Clinically unresponsive patients with acute brain injury activate a brain-computer interface. Oxford Academic

3. Columbia University Medical Center: Confirmed the mechanism of non-invasive brainwave measurement and the future development goal of conveying pain or hunger.
   https://www.cuimc.columbia.edu/news/brain-computer-interface-may-give-unresponsive-icu-patients-voiceColumbia University Irving Medical Center

4. Reddit "r/science": Public comments on the post introducing the research. Referenced for surprise at the results and questions about time and adoption in medical settings. The main points are summarized in Japanese in the text.
   https://www.reddit.com/r/science/comments/1xdajh3/researchers_developed_a_noninvasive_braincomputer/