How to restore connections between brain structures in mental disorders?

, Alexander Khramov,
Doctor of Physical and Mathematical Sciences
“Chemistry and Life” No. 12, 2019

“Remember what he named his race,” the psychologist said quietly. Tagobar blinked his eyes very slowly. When he spoke, his voice was a hoarse whisper - Beings with great power of thought. “Exactly,” Zendoplite confirmed. .

John Gordon, "Honesty is the Best Policy"

Many science fiction novels feature scenes where the hero controls a complex technical device, for example, in Stephen King's novel The Tommyknockers, an alien spaceship is controlled by a person's mental intentions. The question arises: when will we be able to read a person’s thoughts and create devices (or interfaces, in computer language) that translate our mental intentions into certain commands? At least there is already a name for them: neural interfaces or, for simplicity, interfaces.

Neuro - nerve, inter - between, face - face

Artist V. Kamaev
Neurophysiologists and engineers are still so far away from reading thoughts that it is not clear how long. However, the task of creating brain-computer interfaces is gradually being solved. Neural interfaces are devices and programs that use these devices, that is, that record activity in various areas of the brain and translate these signals into commands to control an external device, such as a computer. Brain “activity” can manifest itself in different ways, and we will discuss this below.

The development of brain-computer interfaces itself is in high demand and is therefore developing rapidly. Application areas can be divided into several groups. The first is science, that is, the study of how the brain works. The second group of applications is medicine: diagnosis, treatment and rehabilitation. The third is the “power of thought” control of everything in the world - an excavator on Earth, a research robot on the Moon, an exoskeleton to increase the capabilities of a healthy person, a wheelchair for a disabled person and a car for both of them. And in general, assistance to those partially or completely paralyzed in interacting with external devices, for example, neurochat.pro technology, which allows people with disabilities to communicate. Here, by the way, is the gaming industry - it’s cool to kill monsters with the power of thought! The fourth, not obvious area is the subtle interaction of the brain and external devices, including feedback, when not only a person controls the external device, but also the outside world tells the person something and somehow influences him. This includes training a person’s resistance to stress factors, improving control over one’s psychophysiological state, and developing the ability to evaluate and transmit human emotions to devices.

Progress in all these directions depends on understanding how our brains work and how their work is reflected in what we can observe. Modern interfaces record the macroactivity of the brain in the form of signals from electroencephalograms (EEG), magnetoencephalograms (MEG), and near-infrared spectroscopy (NIRS, Near Infrared Spectroscopy).

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The brain processes incoming sensory stimuli, such as sound, smell, color, taste, received through peripheral nerves, and sends impulses to actuators, such as muscles and glands. In addition, it is responsible for thinking, learning, processing visual information, speech, memory, emotions and the like. All these brain actions are reflected in the recorded brain activity, for example, the movement of a limb is reflected in a very specific way on a person’s EEG. Moreover, if the movement is not real, but only imaginary, then this is also reflected in the EEG.

At the same time, a computer program can process a signal in any complexity; it can learn, adapting both to the task and to a specific person. For such learning, feedback is necessary - the program must receive information about whether it correctly interpreted the received signals, whether it correctly “understood” the particular brain it is working with. At the same time, the program can partly control the patient, orienting him to work with those situations that it recognizes less successfully. You could even say that the brain-computer interface uses artificial intelligence to recognize patterns of brain activity.

The first interfaces mentioned in the scientific literature were developed in 1973–77 by a research group at the University of California with support from the US National Science Foundation and the US Defense Advanced Research Projects Agency. The experiments involved volunteers, on whose heads five electrodes were placed in the occipital and parietal regions, and then the received signals were processed. In those works, the authors analyzed the structural features of EEG signals that arise during the presentation of different images to a person, the so-called visual evoked potentials. But these were the very first attempts.

Five Ways Your Brain Self-Tunes

We mammals are able to create neural connections throughout our lives, unlike species with stable connections. These connections are created as the world around us affects our senses, which send corresponding electrical impulses to the brain. These impulses pave neural pathways along which other impulses will run faster and easier in the future. Each individual's brain is wired for an individual experience. Below are five ways that experience physically changes your brain.

Life experiences insulate young neurons

Over time, a constantly working neuron becomes covered with a sheath of a special substance called myelin. This substance significantly increases the efficiency of the neuron as a conductor of electrical impulses. This can be compared to the fact that insulated wires can withstand a significantly greater load than bare wires. Neurons coated with myelin work without the extra effort that slow, “open” neurons have. Neurons with a myelin sheath appear white rather than gray, which is why we divide our brain matter into “white” and “gray.”

Most of the covering of neurons with myelin is complete by the age of two years, as the child's body learns to move, see and hear. When a mammal is born, its brain must form a mental model of the world around it, which will provide it with opportunities for survival. Therefore, myelin production in a child is maximum at birth, and by the age of seven it decreases slightly. By this time you no longer need to relearn the truth that fire burns and gravity can make you fall.

If you think that myelin is “wasted” on strengthening neural connections in young people, then you should understand that nature designed it this way for sound evolutionary reasons. For most of human history, people had children as soon as they reached puberty. Our ancestors needed to have time to solve the most urgent tasks that ensured the survival of their descendants. As adults, they used new neural connections more than reconfigured old ones.

When a person reaches puberty, the formation of myelin in his body is activated again. This happens because the mammal has to re-tune its brain to find the best mate. Often during the mating season, animals migrate to new groups. Therefore, they have to get used to new places in search of food, as well as to new tribesmen. In search of a marriage partner, people are also often forced to move to new tribes or clans and learn new customs and culture. The increase in myelin production during puberty contributes to all this. Natural selection has designed the brain in such a way that it is during this period that it changes the mental model of the world around it.

Everything you do purposefully and consistently during your “myelin prime” years creates powerful and extensive neural pathways in your brain. This is why human genius so often manifests itself in childhood. That is why little skiers fly past you so dashingly on mountain slopes that you cannot master, no matter how hard you try. This is why learning foreign languages ​​becomes so difficult once adolescence ends. As an adult, you can memorize foreign words, but most often you cannot quickly select them to express your thoughts. This happens because your verbal memory is concentrated in thin, unmyelinated neurons. Your powerful myelinated neural connections are busy with high mental activity, so new electrical impulses have difficulty finding free neurons. […]

Fluctuations in the body's activity in the myelination of neurons can help you understand why people have certain problems at different times in life. […] Remember that the human brain does not mature automatically. Therefore, it is often said that the brain of adolescents is not yet fully formed. The brain “myelinates” all our life experiences. So if there are episodes in a teenager’s life when he receives an undeserved reward, he will firmly remember that the reward can be received without effort. Some parents forgive their teens' bad behavior by saying that "their brains haven't fully matured yet." That is why it is very important to purposefully control the life experience that they absorb. Allowing a teenager to avoid responsibility for his actions can create a mind that will expect the possibility of avoiding such responsibility in the future. […]

Life experience increases synapse efficiency

A synapse is the point of contact (small gap) between two neurons. An electrical impulse in our brain can only travel if it reaches the end of a neuron with enough force to “jump” across the gap to the next neuron. These barriers help us filter truly important incoming information from irrelevant so-called “noise.” The passage of an electrical impulse through synaptic gaps is a very complex natural mechanism. It can be imagined in such a way that a whole flotilla of boats accumulates at the tip of one neuron, which transports the neural “spark” to special receiving docks available at a nearby neuron. Each time the boats cope better with transportation. This is why the experiences we have increase the chances of electrical signals being transmitted between neurons. The human brain has more than 100 trillion synaptic connections. And our life experience plays an important role in conducting nerve impulses through them in a way that is consistent with the interests of survival.

At a conscious level, you cannot decide which synaptic connections you want to develop. They are formed in two main ways:

1) Gradually, through repeated repetition.

2) Simultaneously, under the influence of strong emotions.

[…] Synaptic connections are built based on repetition or emotions you have experienced in the past. Your mind exists because your neurons have formed connections that reflect successful and unsuccessful experiences. Some episodes from this experience were “downloaded” into your brain thanks to “joy molecules” or “stress molecules”, others were fixed in it through constant repetition. When the model of the world around you corresponds to the information contained in your synaptic connections, electrical impulses run through them easily, and it seems to you that you are quite aware of the events happening around you.

Neural chains are formed only due to active neurons

Those neurons that are not actively used by the brain begin to gradually weaken as early as a two-year-old child. Oddly enough, this contributes to the development of his intelligence. Reducing the number of active neurons allows the baby not to glance distractedly at everything around him, which is typical for a newborn, but to rely on the neural pathways that have already been formed. A two-year-old child is already able to independently concentrate on what gave him pleasant sensations in the past, such as a familiar face or a bottle of his favorite food. He may be wary of things that have caused him negative emotions in the past, such as a pugnacious playmate or a closed door. The young brain relies on its limited life experience to meet needs and avoid potential threats.

No matter how the neural connections in the brain are built, you experience them as “truth”

From the age of two to seven years, the process of optimizing the child’s brain continues. This forces him to correlate new experiences with old ones, instead of accumulating new experiences in some separate block. Tightly intertwined neural connections and neural pathways form the basis of our intelligence. We create them by branching out old neural trunks instead of creating new ones. Thus, by the age of seven, we usually clearly see what we have already seen once, and hear what we have already heard once.

You might think this is bad. However, consider the value of it all. Imagine lying to a six-year-old child. He believes you because his brain eagerly absorbs everything that is offered to him. Now suppose you deceive an eight-year-old child. He is already questioning your words because he compares incoming information with what he already has, and does not simply “swallow” new information. At the age of eight, it is already more difficult for a child to form new neural connections, which pushes him to use existing ones. Relying on old neural circuits allows him to recognize lies. This was of great importance from a survival point of view at a time when parents died young and children had to learn to take care of themselves from an early age. During our young years, we form certain neural connections, allowing others to gradually fade away. Some of them disappear like the wind blows away autumn leaves. This helps make a person's thought process more efficient and focused. Of course, with age you gain more and more knowledge. However, this new information is concentrated in areas of the brain where active electrical pathways already exist. For example, if our ancestors were born into hunting tribes, they quickly gained hunter experience, and if they were born into farming tribes, they quickly gained agricultural experience. Thus, the brain was tuned to survival in the world in which they actually existed. […]

New synaptic connections are formed between the neurons you actively use

Each neuron can have many synapses because it has many processes or dendrites. New processes in neurons are formed when it is actively stimulated by electrical impulses. As dendrites grow toward points of electrical activity, they can get so close that an electrical impulse from other neurons can bridge the distance between them. In this way, new synaptic connections are born. When this happens, at the level of consciousness you get a connection between two ideas, for example.

You cannot feel your own synaptic connections, but you can easily see it in others. A person who loves dogs looks at the entire world around him through the prism of this affection. A person who is passionate about modern technologies associates everything in the world with them. A lover of politics evaluates the surrounding reality politically, and a religiously convinced person evaluates it from the standpoint of religion. One person sees the world positively, another - negatively. No matter how the neural connections in the brain are built, you do not feel them as numerous processes similar to the tentacles of an octopus. You experience these connections as “truth.”

Emotion receptors develop or atrophy

In order for an electrical impulse to cross the synaptic cleft, the dendrite on one side must eject chemical molecules that are picked up by special receptors on the other neuron. Each of the neurochemicals produced by our brain has a complex structure that is perceived by only one specific receptor. It fits the receptor like a key to a lock. When you are overwhelmed by emotions, more neurochemicals are produced than the receptor can catch and process. You feel dazed and disoriented until your brain creates more receptors. This is how you adapt to the fact that “something is happening around you.”

When a neuron's receptor is inactive for an extended period of time, it disappears, leaving room for other receptors that you may need to appear. Flexibility in nature means that receptors on neurons must either be used or they can be lost. “Happy hormones” are constantly present in the brain, searching for “their” receptors. This is how you “find out” the reason for your positive feelings. The neuron “fires” because the appropriate hormone molecules open the lock on its receptor. And then, based on this neuron, a whole neural circuit is created that tells you where to expect joy in the future.

Images: © iStock.

Interface classification

Many neural interfaces can be divided into three groups: active, reactive and passive interfaces. The active interface uses changes in brain activity that are directly and consciously controlled by the individual. For example, a person imagines that he is moving his right leg and right arm. Hex-o-Spell typing interface

. The reactive interface generates control commands by studying the brain's response to an external signal, such as light or sound. An example of a reactive interface is an on-screen keyboard with symbols blinking in sequence: the brain responds when the symbol that the person intended blinks. The passive interface analyzes the current brain activity, which occurs on its own during human life. Such interfaces can be useful for creating monitoring systems that monitor emotional states, detect decreased concentration, or loss of control over the system.

Active and reactive interfaces are primarily of interest when working with people with disabilities. Passive, assessing the human state, can find application in the entertainment industry, computer games, neuromarketing, as well as monitoring of certain emotional and functional states of the operator in human-machine systems. They can monitor the operator to see if he is distracted, if he is not overexcited, and finally, simply if he has fallen asleep.

But how can you see what's going on in the brain? Research into how neurons work is needed far beyond just creating interfaces. Monitoring their work makes it possible to detect damage in brain tissue, helps in the diagnosis of brain injuries, neurodegenerative changes in the brain associated with the patient’s age, metabolic disorders and brain lesions on a smaller scale, and in identifying epileptic foci.

The operation of the interface is based on the analysis of information received from the patient through four channels. These are the electrical impulses of neurons, their magnetic activity, the speed of blood flow inside the vessels and changes in metabolism. Let's look at them one by one.

Remember everything: general recommendations

If you are faced with a large flow of information at school or at work and you need to constantly keep data in your head, there are ways to add several gigabytes of memory to your brain.

Understand the meanings

According to the “forgetting curve” compiled by the German psychologist Hermann Ebbinghaus, the retention period of new information in the human brain when rote learning and without understanding is not so long. After an hour, you can remember only 60% of what you studied, after 10 hours - 35%, and after a week - no more than 20%.

Meaningful information is loaded into long-term memory and, therefore, is stored much longer, especially if it is periodically repeated correctly.

Repeat correctly

There is a universal algorithm for repeating information, consisting of 3 stages:

1. Loading. The goal of the stage is to create the strongest possible neural connection by repeating a small volume: on average, 5 units of information in a row, until the next and previous repetitions are equal in speed.
2. Consolidation. The stage consists of regular repetitions of information throughout the week. The goal is to reach maximum speed and maintain it for 7 days, each time increasing the time until the next repetition. You need to repeat it in the same way as at the loading stage.
3. Preservation. The main task is to periodically repeat information so that the speed does not decrease.

You will learn a detailed algorithm for correctly repeating information from this video.

Algori

When you repeat information, divide it into 2 types:

• easy to remember;
• not remembered or remembered worse.

This principle makes it convenient to memorize foreign words. If you use cards (the detailed algorithm is described in the article), during the second repetition, divide them into 2 piles: those words that were remembered instantly, and those that were remembered a little more slowly or not remembered at all. You need to work with each group separately, repeating the “difficult” cards more often.

The “Funnel” allows you to repeat easier and more efficiently, so we recommend doing it this way with a large amount of information.

Spaced repetition

With regular spaced repetition, we recall material one time at a time at specific intervals. But these intervals are not suitable for everyone - each person has his own memory characteristics.

Imagine that you need to boil water. It is unlikely that you will turn the gas on and off at certain intervals: after 2 minutes, then after 10, then after 15. It is better to boil the water immediately and maintain the temperature.

The situation is similar with neural connections—intervals only prevent them from becoming established faster. When neural connections are strong, information is forgotten more slowly and recalled more quickly in memory. Why do we remember the famous line “Frost and sun, a wonderful day!”? All this is the work of strong neural connections.

Source: giphy.com

Therefore, you should repeat until the speed of reproduction of the material stops increasing, that is, the pace of the last 4-5 repetitions will be approximately the same. The intervals between the previous and subsequent repetitions should be gradually increased, and the playback speed should always be increased to the maximum. After a while, you will remember what you have learned faster and faster.

Important: with each new repetition cycle, make sure that the playback speed does not drop.

Be positive

Oddly enough, our mood and thoughts directly affect the process. If initially you constantly tell yourself: “I will never be able to learn this” or “I will never cope with this,” then you are unlikely to achieve your goal. Try to use only positive statements to program your brain to work and achieve great results.

Tell yourself: “I will remember everything!”, “I have a good memory, and I can easily retell this difficult paragraph.” Let yourself know that one way or another you will succeed.

Electroencephalography

Probably all readers of Chemistry and Life know what electroencephalography is. And yet, let us remember that this is a recording of the electrical activity of the brain using electrodes located on the surface of the head (non-invasive, or scalp EEG) or applied directly to the cerebral cortex (invasive EEG, or electrocorticogram). The signal amplitude in the first case is about 100 μV, in the second - ten times more. Electrodes placed directly on the cortex provide more information. They even make it possible to record the activity of individual neurons. But this method has limited applicability only in medical interfaces, when, say, it is necessary to monitor brain activity during surgery. Only non-invasive EEG is suitable for widespread use. However, in medicine it is also used to identify various brain diseases, such as Alzheimer's disease, epilepsy, sleep disorders, attention disorders, as well as the brain's response to neurosurgical interventions.

Signals of electrical activity in the brain are collected using several electrodes placed on the head. This also has its own subtleties. If you use wet electrodes lubricated with conductive paste, the resistance will be lower and the signal will be better, but it is easier to work with dry electrodes. The same problem with quantity: the more electrodes, the more information, but it’s easier to work with fewer. There are also scalp subcutaneous electrodes - everything is clear from the name.

After the signal is removed and cleared of noise and interference (the voltage in the network jumped, something was turned on in the next room, a tram passed under the windows), the most interesting part begins - signal processing. This thing is complex and varied, and in a popular article one can give examples of only the simplest and most traditional processing. One option is to divide the signal into frequency bands by filters and track changes in the amplitude of oscillations in different bands. This method relies on the traditional division of signals supplied by the brain into “rhythms” - alpha rhythm, beta rhythm and others. You can analyze the so-called evoked potentials, that is, characteristic signals that occur when a person is presented with some kind of stimulus (a flash of light, an unfamiliar sound). At the same time, experts associate different elements of the brain’s response with different stages of stimulus processing (notice, compare with known ones, classify, make a decision, remember...).

Different approaches to EEG signals allow us to obtain different speeds of information transmission, but in general we can say that the registration of brain signals in the visual cortex after the presentation of images allows us to realize an information transfer rate of 60–100 bits/min, analysis of sensorimotor rhythms synchronized with real and/or or imaginary motor activity, allows you to achieve information transmission speeds in the range of 3–35 bits/min.

How neural connections are formed

We are born with many neurons, but few connections between them. Neural connections are formed as we interact with the world around us, making us who we are.

Sometimes there is a desire or need to modify already formed connections. It seems that since once in childhood they were formed without much effort, then now it will be as easy as shelling pears. But if an adult does not constantly work on creating them, then it will be more difficult to perceive and remember new data. New nerve chains are not as strong as old ones, and they break down faster.

Source: giphy.com

But there are other methods

Other methods are also suitable for recording brain activity. For example, MEG, which allows you to measure weak magnetic fields generated by ionic currents in brain neurons. Superconducting quantum interferometers, or SQUID sensors, are used to detect very weak magnetic fields. This technology allows you to record events with durations of the order of a millisecond and does not require electrodes, so it is used when working with children and infants. The technology is actually used, but it is very expensive, highly qualified personnel and a special shielded room are needed, because the Earth’s magnetic field and industrial interference exceed the useful signal by nine and six orders of magnitude, respectively.

Recently, near-infrared spectroscopy (NIRS) has been increasingly used to record brain activity. This is a small device in the form of a cap that is worn on the head. Infrared radiation penetrates through the bones of the skull and adjacent tissues into the frontal and occipital cortex of the brain and makes it possible to assess the degree of hemoglobin oxidation, that is, the brain's oxygen consumption. Here, unlike EEG and MEG, a signal of an optical nature is recorded - absorption of infrared radiation; this method, generally speaking, has long been used by chemists, but, of course, not in the head of the subject, but in a cuvette. In our case, the method is most often used to record activity in the primary motor and prefrontal cortex. In the first case, signals corresponding to real and imaginary movements are recorded, in the second case, signals generated by mental calculation and logical problems, musical and visual images.

The tasks that are attempted to be solved through interfaces are varied, but there are general principles for constructing interfaces. The signal is removed from the brain, processed and controlled by an external device. A person sees the result of processing and can correct it, while both the person and the processing program adapt to each other. A person learns to speak clearly, and the system learns to understand him correctly.

Typically, the “language” that a person speaks with an interface is the imagination of the movements of various limbs, which allows for the relatively stable generation of several commands to control an external device (for example, “left”, “right”, “up”, “down”). Moreover, the formation of a team can be either instant or more complex. For example, we can control the movement of a wheelchair through an interface based on an instantaneous brain signal, or monitor its condition and form a team based on its change. In the second case, the system will act somewhat slower, but more reliably.

Some useful information about neurons

Neurons, unlike all other cells in our body, “do not know how” to divide, so until recently scientists were convinced that a person lives his entire life with the limited supply of nerve cells that he received at birth. The results of numerous modern studies have shown that this statement is not true, since neurons are still created throughout our lives. This happens thanks to stem cells, which have the ability to transform into cells of almost any type.

Our brain has its own supply of stem cells. Scientists cannot yet determine the exact number of departments involved in the formation of new nerve cells. What the scientific community knows is that new neurons are formed in the dentate gyrus of the hippocampus, which is responsible for memory and emotion, and a thin layer of cells located along the ventricles of the brain (subventicular zone).

Many newly formed neurons die almost immediately due to the active work of neurotransmitters, the negative influence of the microenvironment, certain proteins and other chemistry occurring in our brain.

In order for a newly formed nerve cell to continue to exist, it needs to form a neural connection (synapse) with other nerve cells. Since the brain does not need lonely floating neurons at all, it simply destroys them, because they do not bring it any benefit and will not be able to bring it in the future. The same neurons that were able to establish connections with other nerve cells are successfully integrated into the structure of our brain.

Every day, about 700-800 neurons can be integrated into the structure of the brain, which managed to survive and form new neural connections.

Brain-programmed cell death, or apoptosis, is a completely normal process that should not be feared. With the help of apoptosis, the brain restores order and gets rid of unnecessary neurons.

The average adult brain consists of approximately 85-88 million nerve cells.

The brain of a newborn contains many more neurons, but by the end of the first year of life their number is almost halved. Psychophysiologist and employee of the Psychological Institute of the Russian Academy of Education Ilya Zakharov explains this by the fact that the human brain develops most actively in the first three years after birth.

Why is this happening? The fact is that it is during this period of time that the child actively explores the world around him: he constantly touches something new, smells it, sees it, tastes it or touches it, etc. All new knowledge is recorded in the baby’s brain in the form of new neural connections, thanks to which all formed and already consolidated skills, all acquired emotional and intellectual experience are preserved.

Although the human brain develops in this way throughout life, it makes its “main breakthrough” in early childhood.

How to apply

Most interface applications are designed for people with severe motor impairments, and their quality of life can be expected to be significantly improved. A fundamentally important parameter here is the speed of information transfer. Patients can be divided into three groups. The first group is patients who are completely immobilized due to the last stage of amyotrophic lateral sclerosis or severe cerebral palsy. The second group is with residual controlled motor activity, for example, eye movement or blinking, lip twitching, etc. The third group is with preserved neuromuscular control, in particular with speech disorders, paresis, etc.

Patients in the first group usually cannot consciously control the interface. For the third group of patients, the use of interfaces is ineffective - there are methods that can provide a higher and more stable speed of information transfer. For example, detecting eye movements can be faster, easier and more accurate than modulations of brain potentials. Using eye movement control technology (eye tracker), a typing speed of about ten words per minute can be obtained. Naturally, hybrid systems have been proposed, for example, combinations of neural interfaces with eye trackers.

Application areas depending on data transfer speed and health status

The figure above shows the relationship between the required information transfer speed, human capabilities and the interface applications available to him.

For the third group, it is not the transfer of information that is of interest, but neurorehabilitation - the restoration of lost motor or cognitive functions in post-stroke patients and patients with spinal cord injuries. It is based on the use of biofeedback for self-regulation of brain activity, which, in turn, occurs due to changes in the topology of the brain's neural networks - that is, the brain begins to use other signal transmission pathways.

Another, although less developed, application of interfaces is monitoring a person’s cognitive abilities in the process of solving various problems and even training his cognitive abilities. Such interfaces are used in neuromarketing and video games to obtain information about users’ emotions, fatigue and concentration. Researchers are now studying the possibility of using such interfaces to recognize pro-epileptic states and suppress epileptic discharges in the brain.

There are a large number of different interface applications - word processors, adapted browsers, wheelchairs, neuroprosthetics; There are also gaming applications. However, most are intended only for training and demonstration, because there are several obstacles on the way to real application, in particular - the speed of information transfer is still low, there are many errors in its transmission, and in many cases the installation of electrodes is required. In addition, the cognitive load on a person is high: it is easier for him to interact with the interface in a quiet laboratory than on a noisy city street. Therefore, the most successful examples of applications were obtained in clinical practice. Finally, there is one specific problem - the user usually has the ability to turn off the interface through specific brain activity, but often cannot turn it back on. In neuroscience this is called the Midas touch

- the gift of golden touch, which was endowed by the greedy king Midas: whatever they touched, everything turned into gold, so it was difficult to use their hands for everyday functions.

And now - a little more about the most important applications of neural interfaces.

How do neural connections influence our perception of the world around us?

Any person, regardless of the level of his spiritual development, is driven by one of three basic instincts: the instinct of reproduction, the instinct of hierarchy and the instinct of survival. They, deeply “sitting” somewhere in the depths of our reptilian brain, clearly and prudently control our lives. It is thanks to instincts that we want to win the recognition and respect of the people around us, stand out from the crowd, love and be loved, give birth and raise children, move forward and solve not only life, but also mathematical or economic problems. Instincts greatly influence our choices and our daily lives.

In animals, the reptilian brain and the limbic system, responsible for the production of “happiness hormones,” are responsible for satisfying the desires caused by the three basic instincts. In our arsenal we have a well-developed cerebral cortex, which gives us the ability to satisfy instinctual desires in millions of different ways. A well-developed cortex allows us not only to realize our instincts, but also to deceive the brain, pretending that, while satisfying instinctual desires, we are actually choosing the right, constructive and useful way.

Why should we engage in self-deception? And then, that the brain, in both the first and second cases, “hands” us a “gift” in the form of a hormonal “bun”.

The essence of this issue lies precisely in the self-deception of our brain: when our brain performs an objectively harmful action, it is internally convinced that this action actually contributes to our survival. The brain perceives an objectively useful action as a threat to survival, so it is often accompanied by stress.

Previously formed neural connections include all our skills, habits and associations. And there is nothing wrong with this, but the whole problem is that most often these connections are created completely by accident, and then these randomly formed neural paths lead us in the wrong direction and become a serious obstacle to our happiness.

✔ If parents constantly praise a child for being good at math, powerful neural pathways are formed in his brain, created by the positive effects of dopamine and serotonin. In this case, mathematics becomes a source of true pleasure for such a child, so he will constantly develop in this direction, and in adulthood he will be able to achieve some significant results and achieve success.

✘ If the parents never encouraged the child and all his endeavors were accompanied by harsh comments, then this neural connection will be “polished” by the negative influence of the hormone cortisol. Over time, the child will hate mathematics, will not want to develop in this direction and will choose a completely different type of activity. As an adult, he may not remember where such a dislike for the exact sciences came from.

This scheme can be applied not only to the choice of activity, but also to people, places, films, books, music, etc. The stronger the hormone release (accompanying emotion), the stronger and faster the neural connection is formed.

Therefore, each of us can at any moment find ourselves as Alice through the looking glass and begin to have a positive attitude towards what is harmful, and will shy away from what is useful. With the help of harmful and excessive pleasures, our brain tries to avoid long-past negativity. Therefore, as an adult, you will avoid mathematics because your parents were negative about your hobby, or you will become addicted to sweets because cakes as a child helped you survive another failure, etc.

The formation of neural connections is influenced not only by hormones and the emotions they cause, but also by the number of repetitions. The more often and regularly you repeat an action, the stronger the neural connection becomes.

If a neural connection leads to an objectively negative result (scandal, physical violence, job loss, obesity, health problems, etc.), and it is not only strong enough, but also “polished” by positive hormones and pleasant emotions, then the human brain will subjectively perceive such a neural connection as necessary and useful.

Neural connections formed through strong emotions and a lot of repetition can lead us to both the Garden of Eden and the gates of hell. And all this happens without any effort on the part of our conscious mind.

Our basic need

Communication is one of the basic human needs. A person who is unable to move his hands or type on a keyboard can use a special application. This is usually a virtual keyboard on the screen. The user selects a letter from the alphabet using an interface that analyzes his EEG. For example, in one of the options, the user only needs to imagine that he is moving his arm or leg to select a particular letter. The entire alphabet is initially divided in half depending on the type of imaginary movement, then in half again, and so on until a specific symbol is selected. The speed of writing messages in this case is from 0.5 to 0.85 characters per minute.

In another system, the characters are displayed on the screen in the form of a matrix. Here, the task of the user, whose EEG response is analyzed in real time, is to focus and concentrate on the selected symbol. Rows and columns of symbols on the screen flash in turn, causing a potential to be generated when the expected symbol is matched. When the desired row blinks on the screen, the EEG changes, and when the desired column blinks, it changes a second time. The typing speed is two characters per minute, the method does not require long training.

An important area is browsers adapted for users with severe disabilities and social networks based on neurotechnologies. An example is the Neurochat communication system (neurochat.pro), designed for network communication between people who are unable to speak or move. The development of the Neurochat system, which has no direct foreign analogues, was carried out under the scientific guidance of Doctor of Biological Sciences A. Ya. Kaplan, head of the laboratory of neurophysiology and neuro-computer interfaces of the Faculty of Biology of Moscow State University named after M. V. Lomonosov. The Neurochat project was created by a private company as part of the National Technology Initiative (NeuroNet roadmap).

Assistive technology and mobility

People who suffer from severe movement disorders spend most of their time at home, so they need apps that give control over household devices, lighting or room temperature. Three variants of such interfaces have already been tested. In the first, a person could use a keyboard, mouse or joystick, in the second, only head trackers and microphones, if the patient had intact neck muscles and could speak. In the third case, with complete disability, the system could be controlled using an EEG. As a result, the user of the interface could, with the power of thought, turn on the light in the room, change the temperature, and turn on the TV. This not only improves the quality of life of the disabled themselves, but also removes some of the burden from the guardian and relatives.

Applications that allow a disabled person to control the wheelchair in which he moves are no less important. However, EEG signals usually contain noise and interference, so false positives are possible, and this is unacceptable for a wheelchair. Therefore, in this case, it is preferable to use invasive methods of recording EEG signals. Experiments with monkeys have shown that, using signals from an electrode array implanted in the motor cortex, our ancestors were able to move a computer cursor to a given point on the screen.

However, invasive EEG recording is still inconvenient, so the creation of non-invasive interfaces looks tempting. It has been shown that it is possible to control wheelchairs solely through the use of EEG signals; the fundamental issue is the inadmissibility of false positives. Therefore, in some developments, the wheelchair control system can itself evaluate obstacles. As a result, the wheelchair operator can move around the room, giving commands forward / backward and left / right, and the system, in case of an error, based on the “room map”, corrects his errors. Making such a system for movement in free space is more than difficult, but work in this direction is underway.

Such neurotechnologies are now increasingly being used to control drones.

Memory techniques

In addition to general recommendations, there are special memorization techniques that can help you load even the most complex terms and formulations into long-term memory.

Mnemonics is a set of techniques that make it easier to memorize any information. Anything that is presented visually recruits a huge number of neurons and creates strong, long-lived neural connections. For more information on how it works, watch this video.

Mind cards

A mind map is a kind of diagram on which information is encoded in the form of symbols. This universal tool helps to optimally structure data and load it into memory as quickly as possible. To create a mind map, you should follow the following algorithm.

1. Prepare

You will need a horizontal sheet of A4 paper and colored pencils or pens. Important: there must be at least four colors so that you can highlight key points in different colors. A bright image activates the right hemisphere of the brain, which is responsible for creativity, thereby facilitating the generation of ideas. Draw by hand - this way the information will be remembered better.

2. Highlight the main idea and key points

Draw a suitable symbol or write the main idea in the center and circle it. Then decide on the main points on this topic, draw semantic branches to them from the center and also circle them.

From the main points, direct branches to subtopics. Important: keep the space between the points, placing them evenly - this will help you not get confused and clearly remember the location of all points.

3. Choose symbols

Each theme and subtheme must be coded using appropriate symbols. They should be drawn from the same place, drawing the branches clockwise, so that you know exactly from which place to read the mind map.

By choosing a symbol and drawing it, we focus on the process. This partly contributes to the memorization of information. The symbols should be bright and memorable so that they are firmly entrenched in your head.

4. Finish the drawing

There is no need to circle the symbols of the last level where your thought ends - at this stage it will be clear which symbol belongs to which branch. Take a few minutes to study the drawing. It is important that you understand what a particular symbol says.

5. Voice your mind map

Speak out loud: start with the main topic, move clockwise to the subtopics, remembering what you meant by the symbols depicted.

6. Play back from memory

Put the original mind map aside and try drawing it on a blank sheet of paper. When restoring a drawing from memory, you can use one color, since in this case the speed of reproduction is important. If you are stuck on some thesis, skip it.

With the help of a mind map, it is easy to move from the main idea to the final one and memorize chapters of books, diplomas, or even entire textbooks. For more information on how to draw mind maps correctly, watch this video.

Cicero's method

It is suitable when you need to remember a large amount of information. The essence of Cicero’s method or, as it is also called, the method of directions, or memory palace, is to create a continuous chain of reference images associated with the necessary data.

The algorithm according to Cicero’s method is as follows:

1. Define a reference system - a space associated with information to be remembered. For example: a room, apartment, office or any room with a familiar environment.
2. Choose the sequence with which you will mentally walk through this space. For example, clockwise.
3. Associate the necessary data for memorization with the location of static objects in this space. It is advisable to follow a certain sequence - this will help you navigate easier. If you need to memorize a text for a lecture, start with the introduction: connect its main points with an object that is located at the beginning of the path, for example, a hanger in the hallway. Moving on to the core of the report, associate each next thought with the next piece of furniture. The connection must be strong, emotional, physical. For more information about the “memory palace”, watch this video.
4. Strengthen the connection by repeating the mental walk 2-3 times.

Pictogram method

Pictograms are great for memorizing poems, literary passages, or reports. The method is based on remembering the text in the form of small drawings, each of which visually reflects the meaning of what is written.

For example, let’s take an excerpt from A. S. Pushkin’s poem “Autumn.” Reading and drawing:

It's a sad time! Ouch charm! I am pleased with your farewell beauty

→ autumn drizzling rain.

I love nature's lush wilting

→ wilted flower.

Forests dressed in scarlet and gold

→ trees with crimson and gold leaves.

In their canopy there is noise and fresh breath

→ wooden house, wind.

And the skies are covered with wavy darkness

→ gray sky with a wavy pattern.

And a rare ray of sunshine, and the first frosts

→ a ray of sunshine and snowflakes break through the gray sky.

And distant threats of gray winter

→ winter in the form of a grandmother who threatens everyone with her fist.

Having created such a graphic letter, place it in front of you and try to reproduce the text. Surely you will be able to remember more than with cramming.

Use of rhymes

This method can be used when studying foreign and Russian languages, as well as when you need to remember first names, surnames or geographical names.

Our brain remembers rhymes much faster and more firmly than ordinary texts. It is on this effect that many advertising slogans are based: “Mirinda. Life is good when you drink slowly” or “Fresh breath makes it easier to understand!”

Back in school, during Russian lessons, we learned exception verbs of the second conjugation using poetry:

Drive, breathe, hold, offend. Hear, see, hate, And depend, and endure, And also watch, twirl.

To study English verbs there is also a whole poem written by teacher Alexander Pyltsyn:

I throw-threw-thrown a brick, (throw) It fly-flew-flown into the window, (fly) My uncle catch-caught-caught, (catch) Bring-brought-brought to mom and dad. (quote) I'm still surprised - Fling-flung-flung where is it from? (leap out)

Source: giphy.com

You can rhyme almost any material for memorization. Moreover, most of the information will remain in memory during the writing process.

Writing abbreviations

Information can be encoded not only using images, but also words starting with the same letters as the desired data. A striking example is the famous phrase: “Every hunter wants to know where the pheasant sits,” which encrypts the colors of the rainbow - red, orange, yellow, green, blue, indigo and violet. Abbreviations can be used to encode any sequence.

Write a list of words you want to remember. For example, the names of the planets of the solar system. Write down the first letters of the names: M V Z M YU S U N P.

Now turn on your imagination and try to come up with some kind of coherent sentence whose words begin with these letters. There can be many options. For example: “On a frosty evening I climbed onto the cabin boy’s mast, trying to see an unfamiliar port.”

Using abbreviations, you can not only remember the necessary material, but also develop creative skills.

Source: giphy.com

Association method

There are two types of associations:

• direct (semantic) - when we imagine images directly related to the object: America = Statue of Liberty;
• phonetic - when we select words based on similarity in sound: Venice = wreath.

Using this method, you can effectively remember paired information, for example:

• countries and their capitals. The capital of Italy is Rome. Many people associate Italy with spaghetti, and Rome with gladiators. Imagine a pumped-up gladiator in armor swimming through a river of spaghetti.
• some historical facts. For example, the writer Alexandre Dumas was born in France. The author is associated with his work - “The Three Musketeers”, and France - with the Eiffel Tower. Imagine a writer wearing a big musketeer hat climbing the Eiffel Tower.
• memorizing foreign words and their translation. Often in this case it is the phonetic association that is suitable. Let's look at this technology using the example of the English word wolf.

To create an image, follow the algorithm:

1. Imagine the image of the Russian word - a huge gray wolf.
2. Encode the word wolf by choosing the consonant Russian. For example, a volcano.
3. Combine these two images into one bright picture - imagine that the wolf is running away from an erupting volcano in fear. To strengthen the connection, say the foreign word out loud several times.

Edge effect

This phenomenon was discovered by the German experimental psychologist Hermann Ebbinghaus. Its essence is that a person quickly remembers and accurately reproduces information located at the beginning and end of the text.

Try our little test for attentiveness and memory. Look at a series of words and try to remember them:

Train, book, radio waves, construction site, pen, bottle, joy, magazine, car, rainbow, pillow.

Surely, the first words on the list you remembered were train and pillow. And in the middle of the list, most likely, you slowed down. How then does the edge effect help in remembering information if we can only reproduce the beginning and the end?

This principle suggests first reading the text that you need to remember, and then highlighting the most difficult parts of it, starting to memorize them first or last. The edge effect does not always work 100% - it all depends on the information being studied, but in most cases it really works.

Feynman method

Theoretical physicist Richard Feynman created a special learning algorithm that will help you study any topic faster and more thoroughly. The essence of the method is to explain new and complex material in clear and simple language that makes it easier to memorize.

First, you should write down everything you know about the topic you need to learn. Then identify “gaps” in knowledge and fill them by writing out new data in as simple a language as possible, avoiding complex terms and long formulations. After that, combine all the information into one simple story, write it down on paper and retell it. It is important that your story is understandable even to a primary school student.

In stories, use visualizations and comparisons, accompanying them with drawings, graphs and clear diagrams - after all, we perceive 90% of information through vision.

For convenience, you can record yourself on a voice recorder - this will help you identify “blind spots” during the retelling and work on them again.

Using the Feynman method, even the most boring and uninteresting material can become an interesting and fascinating story that is easier to understand and remember.

Massive memorization method

This method involves taking notes on the material you want to remember. You will need to write out your main points by hand, using lists and numbering, and paraphrase complex statements into clearer language. If you have the opportunity to highlight the main points directly in the textbook, then use colored markers for this. Such minimal note-taking will help you not only go deeper into the material and remember it, but also quickly refresh your memory of the main points.

Interference

The essence of interference is that similar memories become mixed over time: new data is superimposed on similar old ones, which complicates the memorization process.

For example, to unlock your smartphone you have been using the same pin code or graphic symbol for years. Over time you get tired of it and you change it. At first, every time you unlock, your memory will produce the old version of the password, and you will make a little effort to remember the new code. After a few days or weeks, you will remember the new combination, while you will gradually forget the old one.

To reduce the negative impact of interference, it is recommended to study similar information at different time intervals or break the material into blocks. It is important to organize the memorization process so that the pieces of information studied one after another are as dissimilar as possible.

Useful life hack: if you need to learn a large amount of information, it is useful not only to divide the material into blocks, but also to study them in different rooms: in different parts of the apartment, on the street, in transport. Such a change of environment will help avoid mixing information when memorizing individual parts of the material.

Try using each of the above methods when you get ready to study some material. This way you will understand which one suits you best, and learn to remember any information quickly and for a long time.

Neurorehabilitation

The interfaces help people with stroke and spinal cord injuries recover. This uses biofeedback, which causes self-regulation of brain activity. Common consequences of a stroke are lack of mobility on one side of the body, abnormal muscle tone, poor postural adjustments, and lack of coordination and sensation. As a result of a stroke, half of patients remain permanently in a wheelchair. Thanks to interfaces, people can not only control auxiliary devices (prostheses, exoskeletons), but also restore motor functions by activating plastic mechanisms and changing the topology of the brain’s neural networks.

The disadvantage of EEG for these cases is the low accuracy of the method, that is, the localization of sources of activity in the brain is not accurate enough. Therefore, recording hemodynamic activity measured using fMRI would be useful for neurorehabilitation - but this is a stationary, complex and expensive technique. A possible solution is to use NIRS, near-infrared spectroscopy, to allow the user to deliberately regulate their hemodynamic responses. At the same time, the brain learns, namely, trains to manage its blood supply. This has been shown for both healthy people and post-stroke patients. NIRS-based neural feedback can also be used for long-term training. For example, in recent work from our laboratory it has been shown that, using biofeedback, it is possible to extend the degree of concentration of a person’s attention to certain limits when solving a monotonous task. Although you have to pay for everything: due to the limited cognitive resource of the brain, the degree of concentration itself decreased.

The interface evaluates the person

The purpose of the passive interface is to work with healthy people, and the goal is to increase cognitive abilities during activities associated with high load. Using such an interface, you can monitor the operator’s concentration, cognitive fatigue, and generally the emotional state of the operator. Passive interfaces are already used to assess the condition of drivers, and they are also used in aviation to monitor the condition of pilots and dispatchers. An interesting direction is monitoring the condition of students and schoolchildren during the learning process.

Passive interfaces can be used more widely - to monitor a person’s emotional state. By analyzing EEG signals, it is possible to recognize up to six emotions. For example, systems have been proposed to distinguish between happy/unhappy emotions evoked by pictures and music. In medicine, such systems will help in diagnosing depression and schizophrenia. Non-medical applications, for entertainment and games, are also possible. It would be interesting to study the influence of various external stimuli and internal characteristics of a person on his emotional state. As strange as it may sound, someday along this path we will be able to determine how to make a specific person happy. That is, the system will be able to select music, books and games to make us happy.

Neural insulation defects

Fetal brain development is a complex process in which rapid changes in the morphology and microstructure of nervous tissue occur. In some areas of the brain, the process of myelin formation begins as early as 18–20 weeks of pregnancy, and continues until approximately the age of ten.

It is myelination disorders that often underlie delays in the physical and mental development of a child, and also cause the formation of a number of neurological and psychiatric pathologies. In addition to diseases such as stroke, delays in fetal brain development with impaired myelination are sometimes observed in multiple pregnancies. At the same time, desynchronization in the development of the brain of twins is quite difficult to assess “by eye”.

But how to identify myelin defects during fetal development? Currently, obstetricians and gynecologists use only biometric indicators (for example, brain size), but these are highly variable and do not provide a complete picture. In pediatrics, even in the presence of obvious functional abnormalities in the child’s brain activity, traditional MRI or neurosonography

(ultrasound examinations of the brain of newborns) often do not show structural abnormalities.

Therefore, the search for accurate quantitative criteria for assessing myelin formation during pregnancy is an urgent task, which also needs to be solved using non-invasive diagnostic methods that have already been tested in obstetrics. Specialists from the Novosibirsk International Tomography Center SB RAS proposed using for these purposes a new method of quantitative neuroimaging, already adapted for prenatal ( prenatal)

) research.