Ingenious device allow researchers to “read the minds” of complete locked-in syndrome patients who say they are happy
By Dave Andrusko
Of all the hundreds of stories we have written over the decades about patients with devastating brain injuries, this could be by far, the most amazing.
‘Locked-in syndrome’ is a rare neurological disorder characterized by complete paralysis of voluntary muscles in all parts of the body except for those that control up and down eye movement. Patients can communicate by using simple blinking systems.
But complete locked-in syndrome [CLIS] patients–as was the case in a study the results of which were just published– have lost eye movement as well
In a groundbreaking experiment reported in the journal PLOS Biology, four complete locked-in patients “told doctors they are ‘happy’ using an astonishing new brain computer interface which deciphers their thoughts,” according to Daily Telegraph Science Editor Sarah Knapton. Although incapable of even moving their eyes, they “were able to respond with ‘yes’ or ‘no’ answers to spoken questions.”
“The striking results overturn my own theory that people with complete locked-in syndrome are not capable of communication,” Professor Niels Birbaumer, a neuroscientist at the Wyss Center for Bio and Neuroengineering in Geneva, Switzerland, told Knapton.
“We found that all four people we tested were able to answer the personal questions we asked them, using their thoughts alone. 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.”
As noted, all four were complete locked-in syndrome patients. All suffered from ALS. Prior to this study conducted by a Swiss-led international team of scientists, it was assumed it would be impossible for patients “who were effectively trapped inside themselves to contact the world outside,” Knapton explained.
So how were scientists able to “read their minds”? By use of the aforementioned remarkably ingenious brain-computer interface. Writing in the MIT Technology Review, Emily Mullin explains:
Designed by neuroscientist Niels Birbaumer, now at the Wyss Center for Bio and Neuroengineering in Geneva, the brain-computer interface fits on a person’s head like a swimming cap and measures changes in electrical waves emanating from the brain and also blood flow using a technique known as near-infrared spectroscopy.
Okay, how did they verify the four could communicate?
Birbaumer’s team asked patients, over the course of about 10 days of testing, to respond yes or no to statements such as “You were born in Berlin” or “Paris is the capital of Germany” by modulating their thoughts and altering the blood-flow pattern. The answers relayed through the system were consistent about 70 percent of the time, substantially better than chance.
As you can imagine, “the relief was enormous” for family members. They “were able to communicate with their loved ones after as many as four years of total silence, and to learn they wished to remain alive on ventilators,” Mullin wrote.
Jane Huggins, who runs the Direct Brain Interface Laboratory at the University of Michigan, told Mullin that no one knows how many locked-in patients there are.
Some may be misdiagnosed as being comatose because they lack eye movement or it’s so subtle. Birbaumer and his team say their system could be used as a diagnostic to determine who actually remains conscious and aware, and he hopes to develop a technology to allow people with complete locked-in syndrome to select letters so they can communicate beyond answering yes-or-no questions.