Patients who have been unable to control their bodies for a long time are now able to communicate, according to scientists. Researchers used a brain-computer interface to read the thoughts of patients who were “locked in” their own bodies, and found that they could answer simple yes-or-no questions.
One man reportedly was mentally alert enough to refuse his daughter’s hand in marriage, the BBC states. The four patients, based at the Wyss Center in Switzerland where the study was conducted, likewise showed that they were happy despite their conditions.
All of them had advanced forms of amyotrophic lateral sclerosis, a disease in which the brain loses its ability to control muscle function. This eventually traps people in their bodies – they can think normally, but are unable to move or talk at all. Being “locked in” doesn’t mean there is no way to communicate, as patients are usually still capable of eye movements.
But the patients here could not even move their eyes, as they were “completely locked in.”
Brain activity can change oxygen levels in the blood, which in turn changed the color of blood. Scientists looked inside the brain, using light to detect the color of the blood circulating there, in a technique called near-infrared spectroscopy.
While doing this, the researchers asked the patients basic questions, such as, “Is your husband’s name Joaquim?” in order to train a computer to interpret brain signals. The system was able to achieve a 75% accuracy rate. In short, questions need to be asked repeatedly to make sure the answers were correct.
Professor Ujwal Chaudhary, one of the researchers, says,
It makes a great difference to their quality of life. Imagine if you had no means of communicating and then you could say yes or no – it makes a huge impact.
This form of communication can be used for more practical, daily applications, like asking if a patient is in pain, or wants a family visit.
Professor John Donoghue, director of the Wyss Center, says, “If a person who is totally locked-in is able to communicate, you’re freeing the mind to interact with the world around them. That is remarkable.”
The study was published in PLOS Biology.