Noninvasive Brain-Computer Interface Enables Responses in Some Unresponsive ICU Patients

Cognitive motor dissociation occurs when patients retain signs of consciousness but cannot move or speak to communicate. In the ICU, this hidden consciousness can be difficult to distinguish from coma after acute brain injury, limiting clinicians’ ability to assess intention and basic needs. To improve communication in these cases, researchers have developed a noninvasive brain-computer interface that may allow clinically unresponsive patients to produce responses through brain activity.

The brain-computer interface was developed in a Columbia University study involving Columbia University Irving Medical Center, Columbia University Vagelos College of Physicians and Surgeons, and NewYork-Presbyterian/Columbia University Irving Medical Center. Designed for hospitalized patients with severe acute brain injury, the system uses noninvasive electroencephalography (EEG) electrodes already used routinely to monitor these patients, avoiding the need for implanted brain-computer interface technology.

The system asks patients to control the frequency of a beeping tone played through headphones. A recorded voice instructs them to try to open and close their hands, while EEG electrodes capture the resulting brain activity. A bedside computer analyzes these signals in real time and adjusts the auditory feedback according to the patient’s brain activity.

The study evaluated the system in 41 clinically unresponsive patients with acute brain injury within days of hospitalization. After a brief training period, approximately one-third were able to control the beeping tones using brain activity alone. This group included all patients in whom cognitive motor dissociation had been identified through a separate assessment.

The findings were published in Brain on October 22, 2026, and build on earlier Columbia research using standard EEG and artificial intelligence. In 2019, researchers detected signs of hidden consciousness in 15% of unresponsive patients with brain injury, despite their inability to physically follow commands. EEG recordings suggested that these patients attempted to comply but could not produce the corresponding movements.

Subsequent research linked cognitive motor dissociation to disrupted communication between brain regions involved in higher-order cognition and those controlling muscle movement. Studies also found that patients with this condition were more likely to regain consciousness and recover meaningful everyday functioning, suggesting that identifying it could help predict recovery outcomes. 

Study participants and family members indicated that brain-computer interfaces could be useful and suggested personalized features such as using a loved one’s voice and enabling patients to communicate pain, hunger, or awareness.

“Research in the past decade by us and others has shown that many patients with acute brain injury who appear to be in a coma actually have some level of preserved consciousness, even though they are unable to speak or move their hands or eyes to communicate,” said Jan Claassen, M.D., professor of neurology at Columbia University Vagelos College of Physicians and Surgeons. “Our brain-computer interface is only a first step, but it shows that, in principle, we could hopefully in the future give some of these patients a voice,” added Dr. Claassen.

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Columbia University Irving Medical Center