A team of researchers has developed a technology that allows the decoding of thoughts from patients who suffer from the complete locked-in state (CLIS). This state consists on a full muscular paralysis as the cognitive and emotional systems remain intact.
Patients who suffer from the CLIS condition can feel, touch, and see everything around them, while they cannot even blink. This condition can be produced by either a stroke, a traumatic brain injury, overdoses, or illnesses like the Lou Gehrig disease (amyotrophic lateral sclerosis).
Through all the investigations that have been conducted regarding this condition, it was thought that enabling communications with the outside world in these patients was an impossible task. However, the new findings from the researchers at Wyss Center for Bio and Neuroengineering show otherwise.
The investigation team, composed of researchers from several parts of the world, was able to communicate with patients who suffer the CLIS condition using a noninvasive computer interface system.
The system was configured to decode the CLIS patients’ thoughts when they were asked yes or no questions. The neurological response was processed by the system to translate the thoughts into a definite answer.
To accomplish that task, the research team used a technology called “functional near-infrared spectroscopy,” which is a mechanism that allows the measuring of both the blood oxygenation levels and the blood flow in the brain. The team also performed an electroencephalography, for the mapping of the brain’s electrical activity.
According to the study author Niels Birbaumer, and researcher at the Wyss Center for Bio and Neuroengineering, these findings “are not any surprise, but pleasure.” He stated that with the right training, any caretaker could use this technology and improve the life of the patients and their families.
Andrew Schwartz, professor of neurobiology at the University of Pittsburgh, said that this technology is a great improvement since there is no similar mechanism for this kind of communications existing at the moment.
How the study was conducted
The international investigation team analyzed four different cases from patients with ages between 24 and 76 years old. All of these patients suffer from the completely locked-in state or CLIS condition.
During several weeks, the investigators did sessions with every patient in which they would ask them “yes or no” and “true or false” questions, while connected to the communication interface. When each patient thought the answer, both mechanisms in the system, the near-infrared spectroscopy, and the electroencephalography, did the respective measurements to process the response.
“Usually in computer science, you train a computer to do something using machine learning. But here, they are training a person who cannot communicate to manipulate their brain states to produce an answer,” said Waleed Meleis, associate professor and associate chairman of the department of electrical and computer engineering at Northeastern University.
Every mental state that is linked with “yes” or “no” answers is different and perceivable by the technology used by the researchers. However, the system is not ready to understand the brain well enough and decipher specific letters or words.
The team asked questions like “You were born in Berlin,” or “Paris is the capital of France.” According to the study published in the journal PLOS Biology, in 70 percent of the tests, the patients responded to the questions correctly.
After the researchers had known that the patients were responding the question efficiently, they moved on to ask a more complicated question: “Are you happy?” The results showed that most of the patients have a positive attitude toward life, as many answered “yes.”
Birbaumer explained that a patient’s life quality relies on social care and positive social attention from caretakers, family, and friends.
Long-term investigations finally show substantial improvement
According to Birbaumer, his research team had already communicated with a locked-in patient in 2014. The thing is that on that occasion they only used the near-infrared spectroscopy, and even when the results were not satisfactory, the study was published in the journal Neurology. He stated that this discovery marks not less than 25 years of continuous scientific research.
“I think it’s pretty convincing that they could get ‘yes or no’ answers out of these patients. Now, whether they could get to more sophisticated results, like being able to get language or being able to type, for example, from just your thoughts, that takes more research,” Birbaumer said when presenting the results.
According to Birbaumer, the principal goal for the investigation team is to develop a technology so powerful that can interpret human thoughts and translate them into useful and meaningful pieces of information.
Dr. Brian Litt, a professor, and director of the Penn Center for Neuroengineering and Therapeutics at the University of Pennsylvania highlights the fact that this technology is minimally invasive, and because of that, it can be used by many patients and their families.