Swiss neuroscientists have created a new neurochip that can literally read the minds of people completely paralyzed after car accidents or serious illnesses, according to an article published in the journal PLOS Biology.
“This surprising result disproves my own theory that completely paralyzed people with locked-in syndrome are in fact unable to communicate with the outside world. Our experiments showed that all four volunteers could answer the personal questions we asked them using only the power of thought. If these results can be replicated, we can restore speech to people suffering from motor neuron dysfunction,”says Niels Bierbaumer of the University of Tübingen, Germany.
Inside myself
The so-called "locked-in person syndrome" is the endpoint of certain neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) or Stephen Hawking's disease, as well as the result of various brain injuries, poisoning or drug overdose. With its development, a person seems to lose contact with the outside world and ceases to control the muscles, including the respiratory one, due to damage to motor neurons in the brain and spinal cord.
In general, the symptoms of "locked-in person syndrome" resemble what happens to the body and brain of people in a coma and vegetative state, which is why many neurophysiologists, including Birbaumer himself, believed that paralyzed people, in principle, are not able to conduct a mental activity, set tasks and solve them.
Experimenting with four volunteers in the late stages of ALS, Birbaumer and his colleagues were trying to figure out if they could communicate with them using so-called neurochips and brain-computer interfaces - systems that directly read brain signals and convert them into computer-understandable language.
Scientists used two devices - a magnetic resonance imaging scanner, which monitored the work of different parts of the cortex and deep layers of the brain, and an infrared spectroscope. This relatively new scientific device allows you to monitor the level of activity of individual groups of nerve cells by how much oxygen they consume.
Promotional video:
A light in the end of a tunnel
As the scientists explain, the human body as a whole is transparent to thermal radiation at wavelengths of 700-900 nanometers, but hemoglobin, the main oxygen carrier in our blood, absorbs it. Accordingly, the more oxygen a cell consumes and receives it from erythrocytes, the “darker” it will be for a given device.
Several years ago, another group of scientists found, observing the work of the brain of healthy people, that when answering simple questions, the hemoglobin concentration changes in a predictable way: if you answer "yes", its share in the brain increases, and if you answer "no", it remains the same or falls … Guided by this idea, scientists created a program that translated such signals into “yes” and “no” answers.
Testing the operation of this generally simple system surpassed all the scientists' expectations - four paralytics who took part in the experiment with the consent of their guardians, on the whole, correctly identified their wives and husbands, relatives, answered questions about their personal life, and one of the men even forbade his daughter to marry her boyfriend Mario.
Most of all, scientists were surprised that the participants in the experiments were generally satisfied with the fact that they continue to exist, although the life of some of them had to be supported with the help of artificial ventilation systems.
The confirmation that even people in such a "locked" state continue to want to live and communicate with their own kind, according to Birbaumer, will accelerate research in this area and lead to the development of full-fledged speech synthesizers and devices that will help such patients move on their own.