FAQ: Electroencephalogram (EEG)

7 facts about the brain's electrical activity and the methods of its registration

The electroencephalogram, or EEG, is a total electrical activity of the brain, the electrical signals of cerebral origin that can be registered on the surface of the scalp. To date, the EEG is quite usual procedure, and often people do not realize how unusual that the electricity generated by our brain, we can see directly on the scalp, even did it without damaging. Watching the EEG, we actually observe what is happening in the brain.

• 1.When in 1924 the German psychiatrist Hans Berger first recorded electroencephalogram, for five years he did not dare to publish the results of their observations. And about the same time after the publication of no one wanted to believe him, despite the fact that Berger was a man well versed in scientific procedures. It may interfere with some of its isolation and strangeness, but the most significant was that no one could even imagine that right on the surface of the skin, you can register something coming from the brain. However, when his discovery was confirmed by the British physiologists, it began a boom associated with the use of this method. It turned out very interesting to observe the human brain, a healthy person, not " breaks into " in his skull.
• 2.With the '90s began to force the EEG tomographic methods that are much more accurately determine the location of the sources of activity in the brain. They can be more differentiated study what happens inside the brain, and much deeper into it. EEG is only from the cerebral cortex, but not from the depths of his structures. But EEG has an important advantage: it shows brain activity in real time, as an electric signal is distributed almost the speed of light. Resolution time of other methods is much worse - the order of seconds, at best, share tenths of seconds, and with their help only a relatively slow processes can be observed.
• 3.With electroencephalogram can be seen, above all, major changes in brain activity, for example, when a person changes the level of wakefulness, he begins to doze off or fall asleep. Therefore, the EEG is the leading method in the study of sleep stages. Furthermore, this method does not require bulky hardware. There are portable wearable EEG, which can even be used to record EEG in athletes. To improve you brain just buy – Phenylpiracetam, Cogitum, Pantogam.
• 4.EEG is a sum of the electrical signals from the very large number of nerve cells that use electricity in order to transmit information within the brain. was strong enough to EEG signal and it could be detected on the surface of the head, it takes a huge amount of concurrent and similarly oriented cells. Due to the fact that it spreads very quickly and gives the opportunity to observe what is happening in the brain is actually a real-time, the signal is very useful when we want to understand how quickly the human brain perceives any information from the environment.
• 5.Through EEG and specific method, which is called "evoked potentials" or "potentials related to events" (accumulation of EEG plots linked to external stimuli, such as the presentation of the image with a specific image), it was found that people are very early starts to distinguish between human faces and other objects. Moreover, it is too early to distinguish the animals from non-animal: if it is their show, then after 200 milliseconds in the electroencephalogram can see the difference. The difference in the perception of the brain differ in some subtle signs manifested in the EEG even at the level of the order of 100 milliseconds. These early stages of perception can not be studied with the help of some other methods, not counting one more method is very close to the EEG - it magneto-encephalogram. It is a recording magnetic field produced by the nerve cells simultaneously with an electric current.
• 6.After electroencephalogram XX century method has a new use, in which it is proved competitive compared to all other existing methods, including those that have been created recently. EEG was used brain-computer interface. It is a technology that allows a person to communicate in real time with the outside world using their own brain activity changes. For this technology, devices using, for example, registration of brain blood flow changes were much less suitable - in comparison with electroencephalography they are too slow, too expensive and too cumbersome. They can not be used at home for patients, and they are not available for gamers who are already beginning to acquire the brain-computer interface based on the EEG provides novel unusual sensations during the game.
• 7.Modern EEG are becoming more and more affordable and accessible. They form the basis of game brain-computer interface that can buy almost anyone. They can be used on the move; a person can place the device on his body and record the EEG, doing normal daily activities. Thanks to more advanced mathematical methods of signal analysis in real-time EEG gives more and more information about the brain.