Text on IQ: new data on brain function will help treat dyslexia
Russian scientists have experimentally found out that the human brain is able to recognize text within 150 milliseconds after reading it. Although it was previously thought that this happens several times slower. The new data confirm the existence of a rapid semantic speech processing system in the organ and overturn the classical idea of its consistent perception of information. The results of the experiments will allow specialists to propose new methods of treating dyslexia and other speech disorders. According to experts, the study brings closer the creation of neural interfaces capable of broadcasting films directly into the viewer's mind, as well as new ways to treat autism.
Text processing in a fraction of a second
Scientists from Skoltech and the Institute of Higher Nervous Activity and Neurophysiology (IVND) The Russian Academy of Sciences experimentally studied the operation of a rapid semantic speech processing system. Their research showed that reading comprehension occurs after 150 milliseconds, although previously it was believed that this happens several times slower. The discovery will clarify the fundamental principles of the brain, as well as offer new treatments for dyslexia and other speech disorders caused, for example, by stroke.
— We have found several brain regions that are responsible for rapid semantic processing. Such a system has been discussed before, but this is the first time we have studied it using real texts using magnetic encephalography. Usually, such studies show the perception of individual words, but we used real texts of fairy tales. We took them from different cultures, because depending on them, the text can be organized in different ways," said Gurgen Soghoyan, a researcher at the Skoltech Neurocenter and the Institute of Internal Medicine of the Russian Academy of Sciences.
A group of several dozen participants read fairy tales from the screen. First, they were shown the first word of the sentence, after 150 milliseconds it disappeared and the next one appeared, and so the whole text. After each story, the researchers asked the participants questions about what they had read. It turned out that at this rate, understanding was practically not disrupted, and all participants in the experiment understood the general plot of each fairy tale. People usually read more slowly, focusing for about 200 milliseconds on each word.
During the reading, the participants recorded a magnetic encephalogram (MEG). The MEG data showed that if people were not expecting to see the next word, then their brain activity was higher. This phenomenon is already known in science — such an increased response to semantically unusual stimuli is called N400. However, in previous studies, this reaction was recorded about 400 milliseconds after the presentation of the word (hence the name). In the same study, words were displayed at a speed of 150 milliseconds, that is, 2.5 times faster. This means that the mechanism for recognizing unusual words can be activated in less than 400 milliseconds. This largely changes the usual picture of how the brain processes speech.
— Traditionally, it is believed that text processing in the brain occurs hierarchically and in stages: first, simple physical characteristics are processed, in particular the length of the word, and after some time more complex information is processed, such as how the word fits into the context. The study also shows that this hierarchy is not entirely correct and the processing of semantic information also occurs quite early, about 0.13 seconds after the presentation of the word," said Anastasia Neklyudova, a researcher at the IVND RAS.
It is important that the result is obtained by reading natural text. Previously, these processes were studied mainly in the presentation of individual words or sentences. The study calls into question traditional ideas about the gradual, step-by-step processing of information during reading.
Treatment of speech disorders
At the next stage, the researchers plan to study how the rapid semantic speech processing system works in people with dyslexia. Experts suggest that reading disorders may develop due to changes in her work.
Previously, it was believed that information processing in the brain takes place step by step. First, individual letters are recognized, then words, then sentences. This applies not only to the text, but also to everything else. And the brain centers are also gradually being hierarchically activated. This is a well-known model for processing visual and any other data. But all the latest research refutes it. It happens that higher centers are activated to process the most basic information. At the same time, a huge number of other areas are working at the same time, for example, motor areas, explained neurophysiologist Vladimir Alipov to Izvestia.
— The conducted research will help to create a model of the human brain so that it thinks exactly like a human. Also, based on the data obtained, you can try to create a brain prosthesis. Or make a better neural interface. Now we can read information from the brain quite well, but the problem is to send it there. If we understand how he receives and processes it, we can directly restore vision or hearing. And even, as Elon Musk wants, to broadcast movies," the expert said.
The data obtained by the researchers confirm the theory of predictive coding in speech perception. Instead of simply responding to sensory signals, the brain is constantly generating predictions and adapting to new data, which allows us to effectively understand and interpret speech in various contexts. The principles of predictive coding are applicable not only to the processing of semantic structures, but also to the processing of any sensory information, to coordination of movements and motor skills, says Olga Valaeva, head of the Virtual Clinic Scientific and Practical Center at the Moscow Institute of Psychoanalysis.
— New data on cognitive processes and neurobiology suggest that people with autism may have a more "primary" form of information processing, in which they pay attention to details, but may miss the big picture or context. This may be due to the fact that their brains are less efficient at using predictions to process information," she said.
Autism therapy may be aimed at improving the ability to predict events, emotions, and reactions, the specialist added.
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