“Reading the mind” technology allows paralyzed men to give quick text
WEDNESDAY, May 12, 2021 (HealthDay News) – brain allows a paralyzed man to communicate via text – at speeds approaching the typical phone user.
The achievement is the latest advancement in “brain and computer interface” (BCI) systems.
Scientists have spent years studying BCI technology with the goal of one day giving it to people paralysis or amputations of limbs tend to have greater independence in daily life.
Basically, it works like this: small chips are implanted in areas related to brain movement, and are incorporated into the electrical activity of cells. When a person imagines that he is executing a movement, the corresponding brain cells start firing. These electrical signals are transmitted through cables to the computer, “decoded” through sophisticated algorithms and returned to actions, allowing people to control them. support devices with the strength of themselves.
Researchers at some universities have used BCI to robotically control the small number of patient limbs or to move computer cursors to “write” text.
In a new study, researchers at Stanford University have accelerated this latter skill in a man with full-body paralysis. Instead of mentally moving the computer cursor, the researchers asked him to imagine handwriting.
The approach allowed him to finally double the text at a rate of about 18 words per minute or with mental typing tactics.
The researchers said the man’s performance is almost on par with the average phone user.
“We think it’s pretty remarkable,” said Dr. Jaimie Henderson, a former researcher in neurosurgery at Stanford University in California.
Henderson stressed, however, that technology is limited to the research lab for the time being. Equipment, wires and technical specializations that are not yet realistic for home use are needed.
Krishna Shenoy, a professor of electrical engineering at Stanford and the other lead author of the study, said: “We can’t predict when devices will be available that can be used clinically.”
Both researchers said the findings indicate advances in the field.
“We are very excited about the future,” Henderson said.
Participants in the study – known as T5 – lost almost all movement under the neck in 2007 after suffering a spinal cord injury. Nearly a decade later, Henderson implanted two microchips into the male motor cortex, the outer layer of the brain that voluntarily governs. movement.
Each chip is the size of a child’s aspirin and has electrodes that receive signals from the neurons involved in the movement of the hand.
In a 2017 study, T5 and two other people with paralysis learned to mentally move the cursor around the keyboard displayed on the computer screen, simulating typing. The T5 was finally able to extract 40 characters (i.e. about eight words) a minute.
This time, the researchers tested a new approach where computer algorithms decode mental writing.
First, T5 depicted himself writing individual letters using a yellow legal pen. (“He was very specific about it,” Henderson said.) Through the repetition, the computer software “learned” to know the brain signals associated with the effort made to write a letter given by T5.
He then wrote the sentences in his head and, over time, improved his algorithms by reading neural shooting patterns until he was able to extract 90 characters or 18 words per minute.
It turns out that displaying handwriting – with its curves and speed changes – provides a “rich signal” that is easier to decode than direct cursor movements, Shenoy explained.
Jennifer Collinger is an associate professor at the University of Pittsburgh and is developing BCI technology.
He described the new findings as important scientific advances, but warned that there is still a lot of work to be done before the BCI moves into the real world.
“These systems need to be wireless, reliable and work when they need to,” Collinger said.
The hardware itself, he added, will take many years.
Collinger saw how the different BCI systems that were being developed could be put together: A head-controlled limb could have many everyday uses – but, Collinger said, it might not be a great tool for texting.
The report was published in the journal on May 12 Nature,it was funded through government and private grants. Stanford University has applied for a patent on work-related intellectual property.
The Christopher and Dana Reeve Foundation has more living with paralysis.
SOURCES: Jaimie Henderson, MD, Professor, Neurosurgery, Stanford University Medical Center, Stanford, California; Krishna Shenoy, PhD, Professor of Electrical Engineering, Stanford University; Dr. Jennifer Collinger, Associate Professor, Physical Medicine and Rehabilitation, University of Pittsburgh; Nature, May 12, 2021, online