People with complete locked-in syndrome – incapable of moving even their eyes – have been thought unable to communicate.

But now a brain-computer interface has been able to “read” the yes-or-no thoughts of four individuals with advanced amyotrophic lateral sclerosis when they were asked spoken questions. Two had permanent locked-in syndrome and two were entering the state and had lost the ability to use eye movement to communicate, researchers stated in a paper published in PLOS Biology.

"The striking results overturn my own theory that people with complete locked-in syndrome [CLIS] are not capable of communication. 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," the paper's senior author Professor Niels Birbaumer, a neuroscientist at the Wyss Center for Bio and Neuroengineering in Geneva, Switzerland, said in a statement.

Moreover, these dramatic results also have forced the abandonment of the previously held theory that CLIS patients generally “lack the goal-directed thinking,” authors Birbaumer, Ujwal Chaudhary, Bin Xia, Stefano Silvoni, Leonardo G. Cohen noted.

Scientists had another preconception shattered when all three who, were asked if they were happy, answered “yes.”

"We were initially surprised at the positive responses when we questioned the four completely locked-in participants about their quality of life. All four had accepted artificial ventilation in order to sustain their life when breathing became impossible so, in a sense, they had already chosen to live,” Birbaumer observed. “What we observed was 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 would have a huge impact on the day-to-day life of people with complete locked-in syndrome."



In fact, should this technique prove broadly usable for those with CLIS, significant human contact could be established – right down to the types of “issues” found in any family relationship.

In fact, one family asked if the individual would give permission for his daughter to marry her boyfriend, to which he responded “No” nine of ten times.

The study measured blood oxygenation and brain activity in four subjects using near-infrared spectroscopy (NIRS) and electroencephalography (EEG). The individuals were asked questions, which they could hear. They “learned to answer personal questions with known answers, and open questions all requiring a “yes” or “no” thought, using frontocentral oxygenation changes measured with NIRS,” the study reported.

Three patients were able to finish 46 sessions and one completed 20. The results showed “an above-chance-level correct response rate over 70 percent,” according to researchers.

Professor John Donoghue, director of the Wyss Center, also stressed the critically important promise of wider applications of this technology when he observed that, "restoring communication for completely locked-in people is a crucial first step in the challenge to regain movement, adding, “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 neurological disorders."

This NIRS communication approach is the only one that has been “successful” to date, in those with CLIS.