The NIRS/EEG brain computer interface system shown on a model Wyss Center

People suffering from completely locked-in syndrome have been able to communicate for the first time via a brain-computer interface, telling the research team they felt “happy”. The incredible progress led the trial’s lead professor to predict the method could help “restore useful communication in completely locked-in states for people with motor neuron diseases”.

Brain-computer interfaces have been in testing for years; one of the most remarkable examples being the BrainGate trial in the US which has seen tetraplegics control robotic prosthetics with their thoughts. This trial has enabled people to regain a degree of independence, feeding themselves for the first time in years using only a chip implanted in their brains.


An entirely different approach was taken to help individuals with completely locked-in syndrome (CLIS) - where people can't control even their eye muscles. A team from the Wyss Center for Bio and Neuroengineering in Geneva, Switzerland, headed up by professor Niels Birbaumer, combined near-infrared spectroscopy and electroencephalography (EEG) to specifically help those with no autonomous eye movement. The setup measures electrical signals with an EEG and uses light to measure oxygen levels in the blood. It works like a two-step authentication system - the EEG shows where electrical activity is occurring, the near-infrared spectroscopy confirms if that’s an accurate measure of brain activity by seeing if the same region is also consuming more oxygen. It’s also completely non-invasive.

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Four individuals suffering from advanced amyotrophic lateral sclerosis (ALS), two of whom were in CLIS and the other two “entering the CLIS without reliable means of communication”, were trained to use the system by practising with simple personal questions requiring a “yes” or “no” answer.

Over a period of several weeks, three patients completed 46 sessions, while one completed 20. By testing the system using questions the volunteers already knew the answer to, the researchers found the correct responses were delivered 70 per cent of the time - classed as “above-chance-level correct response rate”. Subjects were able to answer questions about family members accurately, but also open-ended questions. This included nine out of ten “no” answers when one father was asked if his daughter could marry her boyfriend. In what must be an enormous relief to the families of the volunteers, each subject consistently responded “yes” when asked if they were happy over the course of the trial.

Birbaumer admits he was shocked by the results of the trial: "The striking results overturn my own theory that people with completely locked-in syndrome are not capable of communication. We found all four patients we tested were able to answer the personal questions we asked them using their thoughts. If we can replicate this study in more patients, I believe we could restore useful communication in completely locked-in states for people with motor neuron diseases.

"We were initially surprised at the positive responses when we questioned the four completely locked-in patients about their quality of life. All four had accepted artificial ventilation in order to sustain their life, when breathing became impossible; thus, in a sense, they had already chosen to live. What we observed was that as long as they received satisfactory care at home, they found their quality of life acceptable. It is for this reason, if we could make this technique widely clinically available, it could have a huge impact on the day-to-day life of people with completely locked-in syndrome".


In a paper published in PLOS Biology, the team confirms: “If replicated with ALS patients in CLIS, these positive results could indicate the first step towards abolition of complete locked-in states, at least for ALS.”

The Wyss Center’s director, professor John Donoghue, said the institution is committed to making this happen and plans to “develop clinically useful technology that will be available to people with paralysis resulting from ALS, stroke, or spinal cord injury”.

“The technology used in the study also has broader applications that we believe could be further developed to treat and monitor people with a wide range of neuro-disorders."