Brain-computer interface accelerated 5 times
A new type of high-speed non-invasive brain-computer interface has been developed
DailyTechInfo based on Medical Xpress: Researchers develop a fast, noninvasive brain-computer interfaceOver the past two decades, scientists have been developing interfaces that can link the human nervous system and brain directly to a computer, a technology that was previously only the subject of science fiction.
The implementation of such interfaces already allows you to create neural interfaces between "smart" prostheses and the nervous system, which radically change the lives of people suffering from violations of communicative functions and sensory-motor motility. In addition, the brain-computer interface (BCI) may in the near future become the bridge on which completely new paradigms of human interaction with computers and other electronic devices will be based.
One of the obstacles that limit the practical application of BCI interfaces at the present time is their low-speed communication indicators. The most common method of implementing such interfaces are electroencephalography technologies (electroencephalogram, EEG), non-invasive technologies for taking pictures of brain activity, characterized by simplicity and low cost. Unfortunately, EEG systems have a very low value of the signal-to-noise ratio, so the transmission rate of useful information in such systems is extremely low and is on the order of 1 bit per second. It is at this speed that a fairly popular application works, which, through the computer's speaker system, pronounces aloud a test read by a person from the screen.
Invasive technologies, in which electrodes or sensors are inserted into the brain by surgical intervention, provide higher information exchange rates. But their use is also far from practicality due to a number of obvious reasons. And recently, scientists from the University of California and Jinghua University in Beijing have developed a new type of non-invasive BCI interface that provides the highest speed of information exchange to date.
The researchers named their system Steady-State Visual Evoked Potentials (SSVEP). It works by registering the direction of a person's gaze focused on a sign. All this is something like a virtual keyboard, the keys of which should not be pressed with fingers, but pointed with a glance. The SSVEP prototype has already made it possible to achieve a record value of the information input speed. At its current level of implementation, the SSVEP system allows a person to "write" at a speed of 50-60 characters per minute, which corresponds to an information exchange rate of 4.5-5.5 bits per second, but with additional training of a person, during which he will gain experience in this matter, the speed of information input can increase even more, and moreover significantly.
The SSVEP system uses not only tracking the movements of a person's eyes, but also a picture of his brain activity is involved in the process. Flashes of neural activity of a certain type serve as signals confirming the choice of a symbol and at the same time as a kind of "filter" that allows you to get rid of noise signals. And in the near future, researchers plan to introduce synchronous modulation-demodulation algorithms into it, which will improve the quality of decoding neural signals, and an adaptive decoding algorithm that can independently adapt to the individual characteristics of each person's visual perception.
Article by Xiaogang Chen et al. High-speed spelling with a noninvasive brain–computer interface is published in PNAS – VM.
Portal "Eternal youth" http://vechnayamolodost.ru
02.11.2015