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7. PSYCHOPHYSIOLOGY OF MEMORY

Lecture



One of the main properties of the nervous system is the ability for long-term storage of information about external events.

By definition, memory is a special form of mental reflection of reality, consisting in fixing, saving and subsequent reproduction of information in a living system. According to modern concepts, not individual information elements are fixed in memory, but holistic knowledge systems that allow all living things to acquire, store and use a vast stock of information in order to effectively adapt to the surrounding world.
Memory as a result of learning is associated with such changes in the nervous system that persist for some time and significantly affect the further behavior of a living organism. The complex of such structural and functional changes is associated with the process of engram formation - i.e. traces of memory (the term proposed by the zoologist J. Young in the 1950s).
Memory also acts as a kind of information filter, since only a tiny fraction of the total number of stimuli acting on the body is processed and stored in it. Without selection and exclusion of information from memory, a living being would, figuratively speaking, be “flooded” with an endless stream of stimuli coming from outside. The results of this would be as catastrophic as the lack of ability to learn and remember.

7.1. Classification of memory types

Penetrating all aspects of human existence, memory has different forms and levels of manifestation and functioning.

7.1.1. Elementary types of memory and learning

7. PSYCHOPHYSIOLOGY OF MEMORY In neurophysiology , the following elementary mechanisms of learning are distinguished: habituation , sensitization, temporary connection ( conditioned reflex ). According to I.P. Pavlov, the physiological basis of memorization is the conditioned reflex as an act of the formation of a temporary connection between the stimulus and the reaction. These forms of memory and learning are called simple to distinguish from learning that has an arbitrary, conscious character. Even invertebrates have elementary forms of learning.
The addiction manifests itself in a gradual decrease in the reaction as the stimulus is re-presented. Habituation always accompanies the extinction of the orienting reaction . Sensitization is the opposite of addiction. It is expressed in lowering the threshold when presenting stimuli. Thanks to sensitization, the body begins to react to a previously neutral stimulus.
There is also a division of memory into genotypic and phenotypic . The first is genotypic, or phylogenetic, associated with unconditioned reflexes and instincts. The second one, phenotypic, provides processing and storage of information acquired during ontogenesis based on various learning mechanisms.

7.1.2. Specific memory types

In the course of improving adaptation mechanisms, more complex forms of memory were developed and consolidated, connected with capturing various sides of individual experience.

Modal-specific species. Mnestic processes can be associated with the activity of different analyzers , therefore there are specific types of memory according to the sense organs: visual, auditory, tactile, olfactory, motor. It should be mentioned that the level of development of these types of memory is different for different people. It is possible that the latter is associated with the individual features of the analyzer systems. For example, there are individuals with an unusually developed visual memory. This phenomenon - eidetism - is expressed in the fact that at the right moment a person is able to reproduce in detail the previously seen object, picture, page of the book, etc. The eidetic image differs from the ordinary one in that the person continues to perceive the image in his absence. It is assumed that the physiological basis of eidetic images is the residual excitation of the visual analyzer. A well-developed modally-specific memory is often a professionally important quality: for example, the auditory memory of musicians, taste and olfactory tasters, motor gymnasts, etc.

7. PSYCHOPHYSIOLOGY OF MEMORY Shaped memory. The imprinting and reproduction of pictures of the world around us are associated with the synthesis of modal-specific impressions. In this case, complex images are fixed, combining visual, auditory, and other modal-specific signals. This memory is called figurative. The figurative memory is flexible, spontaneous and provides long-term storage of the track.
According to some ideas, its morphological basis is formed by complex neural networks, including interconnected neural links located in different parts of the brain. Therefore, the loss of any one link or several links of figurative memory is not capable of destroying its entire structure. This gives figurative memory great advantages both in the efficiency of the processes of assimilation and storage, and in the volume and strength of information fixation. It is likely that sudden, often without any effort of recalling forgotten material, are associated with such features of figurative memory.
In addition, sometimes emotional and verbal-logical memory is also distinguished.

Emotional memory. Emotional memory is associated with memorizing and reproducing emotional experiences. Emotionally tinged memories can occur both with repeated exposure to stimuli that cause this condition, and in the absence of the latter. The emotionally colored impression is fixed almost instantly and involuntarily, providing replenishment of the subconscious sphere of the human psyche. The information is also involuntarily reproduced from the emotional memory. This type of memory is in many ways similar to the figurative, but sometimes the emotional memory is even more stable than the figurative. Its morphological basis is supposedly served by distributed neural networks, including the neuronal groups of their different parts of the cortex and the nearest subcortex .

Verbal-logical memory. Verbal-logical (or semantic) is a memory for verbal signals and symbols denoting both external objects and internal actions and experiences. Its morphological basis can be schematically represented as an ordered sequence of linear links, each of which is connected, as a rule, with the preceding and following. The chains themselves are only interconnected in separate links. As a result, the loss of even one link (for example, due to organic lesion of the nervous tissue) leads to the break of the entire chain, disruption of the sequence of stored events and to the loss of more or less information from the memory.

7.1.3. Temporary memory organization

  • Another basis for classifying memory is the duration of the fixation and preservation of the material. It is accepted to divide memory into three types:
    • iconic, or sensory, memory (PI);
    • short-term, or operational, memory (COI);
    • long-term, or declarative, memory (DVP).

Sometimes the latter type of memory is called propositional, secondary or semantic. It is believed that each of these types of memory is provided by different brain processes and mechanisms associated with the activity of functionally and structurally different brain systems.
The storage time in the sensory, or iconic, memory is 250-400 ms, but according to some data this process can last up to 4 seconds. The volume of IP in the presence of the relevant instructions from 12 to 20 elements. Storage time in short-term memory is about 12 seconds, with repeated longer. The volume of KVP is represented by the widely known Miller number 7 ± 2 elements. Storage time in fiberboard is indefinitely long, the volume is large, according to some ideas, unlimited.
Such a temporary typology of memory is confirmed by experiments with animals according to learning, in which it is shown that memorization worsens if an electric shock follows immediately after learning (electroconvulsive shock - EKSH), i.e. EKSH prevents the transfer of information from short-term memory to long-term. Similarly, a trauma received by a person does not immediately affect the reproduction of events, but after a few minutes a person cannot accurately remember all the circumstances of the incident.
The existence of two different storages of memory (long-term and short-term) is indicated by such facts. Two groups of subjects - healthy and patients with amnesia - were to reproduce the list of 10 words immediately after memorizing and with a delay of 30 seconds. At the time of the delay, the subjects of both groups had to solve an arithmetic problem. Significant differences between the two groups of subjects during immediate reproduction were not found, while with delayed reproduction in patients with amnesia, the volume of memorization was much lower. This experiment confirms that the mechanisms of short-term and long-term memory in humans are different.

  • In all of the above types of memory there is a fixation of information, which includes at least three stages:
    • engram formation, i.e. the trace left in the brain by one or another event;
    • sorting and highlighting new information;
    • long-term storage of relevant information.

7.1.4. Sealing mechanisms

A difficult problem is the mechanism of the formation of traces of memory, the selection of structural entities involved in the storage and reproduction of existing traces, as well as those structures that regulate these processes.

7. PSYCHOPHYSIOLOGY OF MEMORY Experiments K. Leshley. Karl Lashley, a pioneer in the field of memory research, tried to provide an answer to the spatial arrangement of memory with the help of surgical intervention in the brain, by analogy with speech, motor or sensory zones. Lashley taught different animals to solve a specific problem. Then, one by one, he removed various parts of the cortex from this animal - in search of the location of the memory marks - engrams. However, no matter how much cortical tissue was removed, it was not possible to find the specific place where traces of memory (engrams) are stored. He concluded his classic article by concluding that memory is simultaneously in the brain everywhere and nowhere.
Subsequently, these facts were found explanation. It turned out that not only the cortex is involved in memory processes, but many subcortical formations and, moreover, traces of memory are widely represented in the cortex and at the same time are duplicated many times over.

Stages of the formation of engrams. According to modern concepts, the fixation of the trace in memory is carried out in three stages.
At the beginning , in the iconic memory, a sensory trace (visual, auditory, tactile, etc.) arises on the basis of the activity of the analyzers. These traces make up the contents of the sensory memory.
At the second stage, sensory information is sent to the higher parts of the brain. In the cortical zones, as well as in the hippocampus and the limbic system, signals are analyzed, sorted and processed, in order to extract new information from the organism. There is evidence that the hippocampus together with the medial part of the temporal lobe plays a special role in the process of consolidation (consolidation) of memory traces. We are talking about the changes that occur in the nervous tissue during the formation of engrams. The hippocampus appears to play the role of a selective input filter. It classifies all signals and discards random ones, contributing to the optimal organization of sensory traces in long-term memory. He also participates in the extraction of traces from long-term memory under the influence of motivational arousal. The role of the temporal region is presumably that it establishes a connection with the storage sites of memory traces in other parts of the brain, primarily in the cerebral cortex. In other words, she is responsible for the reorganization of the neural networks in the process of assimilating new knowledge; when the reorganization is completed, the temporal region does not participate in the further storage process.
At the third stage, trace processes become stable structures of long-term memory. The transfer of information from short-term memory to long-term, according to some assumptions, can occur both during wakefulness and in sleep.

Memory management systems. An important parameter in the classification of memory is the level of control, or regulation, of the mnestic processes. On this basis, emit involuntary and arbitrary memory. In the first case, memorization and reproduction occurs without effort, in the second, as a result of conscious mnestic activity. Obviously, these processes have different brain support.
In general, the system of control and regulation of memory in the brain includes non-specific and specific components. At the same time, there are two levels of regulation: 1) non-specific (cerebral) - this includes the reticular formation, hypothalamus, non-specific thalamus, hippocampus and frontal cortex; 2) modal-specific (local) associated with the activity of analyzer systems.
According to modern concepts, non-specific level of regulation is involved in providing virtually all types of memory. It is known from the clinic of focal brain lesions that there are so-called modal-nonspecific memory disorders, when the weakening or loss of memory functions does not depend on the nature of the stimulus. They occur with the defeat of deep brain structures: reticular formation of the trunk, diencephalic region, limbic system, hippocampus. In the event of damage to the hippocampus, a known disease occurs - Korsakoff syndrome , in which the patient loses memory for current events with comparative safety of traces of long-term memory.
It was also established that with activation of the reticular formation, the formation of engrams occurs more efficiently, and with a decrease in the level of activation, on the contrary, both involuntary and voluntary memorization of any new material worsens, regardless of its complexity and emotional significance. Along with this, an improvement in short-term memory (an increase in volume upon presentation of information at a rapid pace) can be observed with electrical stimulation of the thalamocortical system. At the same time, with the destruction of a number of areas of the thalamus, difficulties arise in the assimilation of new information or in the preservation of the previously learned.
The frontal lobes of the cortex, especially the left frontal lobe, play a leading role in ensuring voluntary memorization, or mnestic activity.
The modal-specific, or local level , of memory regulation is provided by the activity of analyzer systems, mainly at the level of the primary and associative zones of the cortex . With their violation, there are specific forms of violation of mnestic processes that are selective.
It follows from the above that the system of regulation of memory has a hierarchical structure, and the full provision of functions and processes of memory is possible only if all its links are functioning. Memory should be understood as a systemic (emergent) property of the whole brain and even the whole organism. Therefore, the level at which the understanding of memory is possible is the level of the living system as a whole (see Chrestomat. 7.2).

7.2. Physiological Theories of Memory

In modern neurobiology and psychophysiology, there are a number of theories and models that explain the different aspects of memory functioning.

Theory D. Hebba. The first studies of the physiological bases of memory are associated with the name of D. Hebb. In the 40s. he introduced the concepts of short-term and long-term memory and proposed a theory explaining their neurophysiological nature. According to Hebb, short-term memory is a process caused by the repeated excitation of impulse activity in closed neuron circuits, which is not accompanied by morphological changes. Long-term memory , by contrast, is based on structural changes resulting from the modification of cell – cell contacts - synapses. Hebb believed that these structural changes are related to the re-activation (by his definition - “repeating excitation reverberation ”) of closed neural circuits, for example, paths from the cortex to the thalamus or the hippocampus and back to the cortex.
Repeated excitation of neurons that form such a chain leads to the fact that long-term changes occur in them, associated with the growth of synaptic connections and an increase in the area of ​​their contact between the presynaptic axon and the postsynaptic cell membrane . After the establishment of such connections, these neurons form a cell ensemble , and any excitation of at least one neuron belonging to it, leads to the excitation of the entire ensemble. This is the neuronal mechanism for storing and retrieving information from memory. Непосредственно же основные структурные изменения, согласно Хеббу, происходят в синапсах в результате процессов их роста или метаболических изменений, усиливающих воздействие каждого нейрона на следующий нейрон.
Достоинство этой теории в том, что она толкует память не как статическую запись или продукт изменений в одной или нескольких нервных клетках, а как процесс взаимодействия многих нейронов на основе соответствующих структурных изменений.
Современные подходы к изучению физиологических механизмов памяти в значительной степени связаны с развитием изложенных выше идей Д. Хебба.

Синаптическая теория. Свое название эта теория получила из-за того, что главное внимание в ней уделяется роли синапса в фиксации следа памяти. Она утверждает, что при прохождении импульса через определенную группу нейронов возникают стойкие изменения синаптической проводимости в пределах определенного нейронного ансамбля.
Один из наиболее авторитетных исследователей нейробиологических основ памяти, С. Роуз подчеркивает: при усвоении нового опыта, необходимого для достижения каких-либо целей, происходят изменения в определенных клетках нервной системы. Эти изменения, выявляемые морфологическими методами с помощью световой или электронной микроскопии, представляют собой стойкие модификации структуры нейронов и их синаптических связей.
Г. Линч и М. Бодри (1984) предложили следующую гипотезу. Повторная импульсация в нейроне, связанная с процессом запоминания, предположительно, сопровождается увеличением концентрации кальция в постсинаптической мембране, что приводит к расщеплению одного из ее белков. As a result, masked and previously inactive protein receptors (glutamate receptors) are released. By increasing the number of these receptors, a state of increased conductivity of the synapse occurs, which can last up to 5-6 days.
Эти процессы тесно связаны с увеличением диаметра и усилением активности так называемого аксошипикового синапса — наиболее пластичного контакта между нейронами. At the same time, new spines on the dendrites are formed, and the number and size of synapses increase. Thus, the morphological changes accompanying the formation of a memory trace are experimentally shown.

Реверберационная теория. Основания теории были выдвинуты известным нейрофизиологом Л. де Но. Теория базировалась на существовании в структурах мозга замкнутых нейронных цепей. Известно, что аксоны нервных клеток соприкасаются не только с дендритами других клеток, но могут и возвращаться обратно к телу своей же клетки. Благодаря такой структуре нервных контактов, появляется возможность циркуляции нервного импульса по реверберирующим (постепенно затухающим) кругам возбуждения разной сложности. В результате возникающий в клетке разряд возвращается к ней либо сразу, либо через промежуточную цепь нейронов и поддерживает в ней возбуждение. Эти стойкие круги реверберирующего возбуждения не выходят за пределы определенной совокупности нервных клеток и рассматриваются как физиологический субстрат сохранения энграмм . Именно в реверберационном круге возбуждения происходит переход из кратковременной в долговременную память.
С этим непосредственно связана гипотеза А.С. Батуева о двух нейронных системах, обеспечивающих оперативную память. Одна система, включающая "нейроны памяти", работает на эстафетно-реверберационном принципе передачи информации, когда отдельные группы нейронов памяти вовлекаются друг за другом, представляя собой своеобразные "нейронные ловушки", поскольку возбуждение в них циркулирует в течение 1,5-2 с. Другая система обеспечивает надежность переходных процессов: переключение информации с "сенсорных" нейронов на "нейроны памяти" и далее на нейроны "моторных программ" и т.д. Их взаимодействие позволяет эффективно запоминать текущую информацию.
Однако реверберационная теория не дает ответа на ряд вопросов. В частности, она не объясняет причину возврата памяти после электрошоковых воздействий, когда, согласно этой теории, в подобных случаях возврата памяти не должно быть.

Нейронные модели памяти. С развитием микроэлектродной техники появилась возможность изучения электрофизиологических процессов, лежащих в основе памяти на уровне нервной клетки. Наиболее эффективным оказался метод внутриклеточного отведения электрической активности отдельного нейрона. С его помощью можно анализировать роль синаптических процессов в изменении активности нейрона. В частности, на этой основе были установлены нейронные механизмы простой формы обучения — привыкания (см. п. 7.1.1).
Изучение нейронных основ памяти сопряжено с поиском структур, нейроны которых обнаруживают пластические изменения при обучении. Экспериментальным путем такие нейроны обнаружены у животных в гиппокампе, ретикулярной формации и некоторых зонах коры.
Исследования М.Н. Ливанова и С.Р. Раевой показали, что активация оперативной памяти у человека сопровождается изменением активности нейронов многих структур мозга. При применении тестов на оперативную и непроизвольную память были обнаружены "пусковые" нейроны, расположенные в головке хвостатого ядра и передней части зрительного бугра, которые отвечали лишь на речевые команды типа: "запомните", "повторите".
В контексте векторной психофизиологии (см. тему 1 п. 1.4.4) разрабатывает нейронную модель памяти Е.Н.Соколов. По его представлениям, разнообразная информация закодирована в нейронных структурах мозга в виде особых векторов памяти, которые создаются набором постсинаптических локусов на теле нейрона-детектора, имеющих разную электрическую проводимость. Этот вектор определяется как единица структурного кода памяти. Вектор восприятия состоит из набора постсинаптических потенциалов разнообразной амплитуды. Размерности всех векторов восприятия и всех векторов памяти одинаковы. Если узор потенциалов полностью совпадает с узором проводимостей, то это соответствует идентификации воспринимаемого сигнала.

Частотная фильтрация и память. Концепция частотной фильтрации предполагает, что обработка информации в зрительной системе осуществляется через нейронные комплексы, наделенные свойствами двумерных пространственно-частотных фильтров. Такие фильтры осуществляют анализ параметров стимула по принципу, описываемому разложением Фурье.
При этом механизмы хранения энграмм находят своеобразное выражение в концепции пространственно-частотного анализа. Предполагается, что в памяти фиксируется только гармонический состав нервных импульсов, а узнавание знакомых объектов упрощается за счет того, что отношение частот внутри гармонического состава не зависит от абсолютной величины импульса. Именно поэтому для оперативной памяти требуется столь малый объем.
В то же время в контексте этой модели конкретные механизмы функционирования памяти еще далеко не ясны. Однако показано, что различные пространственные частоты по-разному взаимодействуют с памятью: высокочастотная информация сохраняется в кратковременной памяти дольше, чем низкочастотная. Кроме того, нейронные механизмы, формирующие основные функциональные свойства фильтров, их пространственно-частотную избирательность, по-видимому, различным образом представлены в долговременной памяти.

Математическое моделирование памяти. Математическое моделирование на уровне суммарной биоэлектрической активности мозга применяется и к изучению памяти. Исходя из представлений об импульсном кодировании сигналов в памяти и цикличности нейронных процессов А.Н. Лебедев предлагает математическую модель, которая используя некоторые характеристики основного ритма электроэнцефалограммы — альфа-ритма — позволяет количественно оценить объем долговременной памяти и некоторые другие ее характеристики.
Physiological bases of memory, according to A.N. Lebedev, serve as a bundle of neural impulses capable of cyclically repeated. Each burst of pulses is a kind of "letter" of the universal neural code. How many different packs by the number of pulses in each, so many different letters in the neural code. Bundles arise one after another and form limited chains. These are code words. Each chain, i.e. to each code word, there corresponds its own ensemble of neurons generating it.
В результате каждому приобретенному образу памяти (слову, предмету, явлению и т.п.) соответствует свой нейронный ансамбль. Нейроны ансамбля, хранящие один образ, активизируются согласованно, циклически. Колебания клеточных потенциалов, связанные с импульсацией нейронов, создают повторяющийся узор биопотенциалов. Причем каждому образу соответствует свой собственный узор. Часть нейронов ансамбля могут "замолкать" или включаться в работу другого ансамбля, другого образа. При этом ансамбль может не только приобретать нейроны (повторение), но и терять их (забывание). Предполагается, что работу одного ансамбля может обеспечить число нейронов от 100 до 1000. Нейроны одного ансамбля не обязательно размещаются рядом, однако часть нейронов любого образа с необходимостью располагается в ретикулярной формации ствола и промежуточного мозга, другие нейроны размещаются в старой и новой коре, в ее первичных, вторичных и третичных зонах.
A.N. Лебедев предполагает, что узоры, образованные волнами активности какого-либо ансамбля, повторяются чаще всего через 100 мс, т.е. после каждого нервного импульса клетка "отдыхает", восстанавливаясь в течении 10 мс. Это так называемая относительная рефрактерная фаза, снижающая способность нейрона включаться в коллективную деятельность под влиянием протекающих к нему импульсов от других нейронов. Таким образом синхронные импульсы многих нейронов ансамбля возникают друг за другом с промежутками около 1 мс, составляя группу, которая и является минимальной кодовой единицей памяти. Цепочка из групп, появляющаяся в одном цикле активности, может быть названа нейронным, кодовым "словом", а отдельная группа в составе слова — кодовой "буквой".
Представление о циклических кодах памяти оказалось также продуктивным и для теоретического расчета быстродействия памяти, проявляющегося в скорости мнемического поиска и быстроте принятия решения в ситуации выбора(см. Хрестомат. 7.1).

7.3. Биохимические исследования памяти

Поиску специфических веществ, ответственных за хранение информации — "информационных молекул", посвящено немало исследований. Исходно эти исследования опирались на предположение, что все этапы формирования, удержания и воспроизведения энграмм можно представить в виде последовательности биохимических процессов.

7. PSYCHOPHYSIOLOGY OF MEMORY "Memory Molecules". The first hypotheses linking the recording of information with biochemical changes in the nervous tissue were born on the basis of those widely known in the 1960s. G. Hiden's experiments, which showed that the formation of memory traces is accompanied by changes in the properties of RNA and protein in neurons. It was found that irritation of the nerve cell increases the content of RNA in it and leaves long-lasting biochemical traces that tell the cell the ability to resonate in response to repeated actions of the same stimuli. Thus, it was found that RNA plays an important role in the mechanisms of formation and preservation of memory traces. However, in later works it was shown that in the consolidation of memory engrams the leading role is played by DNA, which can serve as a repository of not only genetic, but also acquired information, and RNA ensures the transmission of a specific information code. It has even been suggested that the inability of mature neurons to divide is intended to prevent the destruction of acquired information stored in the DNA of the neuron.
These discoveries had a great scientific and public response.
Some researchers, for example, got carried away with the idea of ​​improving memory by introducing these biochemical components into the diet. However, if we keep in mind that large molecules of this type break up in the intestine into their constituent amino acids before they are included in the metabolism of the consumer, reliable results could not be obtained here.
Another example of the same logic was the attempt to transfer ("memory transport") from trained animals to untrained ones. Methodically, this was done by injecting the brain substrate of a donor animal, trained in simple skills, to a recipient animal that had not previously been trained. In connection with this, the experiments of G. Ungar, who attempted to isolate a special substance, the peptide "scotofobin", transmitting information about the fear of darkness, became most popular. Numerous checks that followed this discovery did not give positive results.
So, the concepts of biochemical coding of individual experience in memory are based on two groups of facts: 1) education in the brain when teaching new biochemical factors (for example, "memory peptides"); 2) the ability to transfer acquired information to the untrained brain using these factors. However, the idea of ​​the existence of biochemical factors capable of preserving and transferring information is perceived critically by most researchers. At present, it is believed that the molecular coding hypothesis of individual experience has no direct factual evidence. Despite the fact that the essential role of nucleic acids and proteins in the mechanisms of learning and memory has been established, it is assumed that RNA and proteins that are involved in the formation of a new associative bond are specific only in relation to the functional change of synapses involved in the process and are not specific to the information itself.

Mediator systems. Mediators - chemical mediators in synaptic transmission of information - are given great importance in providing mechanisms for long-term memory. The main mediator systems of the brain - cholinergic and monoaminoergic (including noradrenoergic, dopaminergic and serotonergic) - are directly involved in learning and the formation of memory engrams. Thus, it has been experimentally established that reducing the amount of norepinephrine slows down learning, causes amnesia and disrupts memory traces.
R.I. Kruglikov (1986) developed a concept according to which complex structural-chemical transformations at the systemic and cellular levels of the brain underlie long-term memory. At the same time, the cholinergic system of the brain provides the informational component of the learning process. The monoaminoergic systems of the brain are more associated with the provision of reinforcing and motivational components of the learning and memory processes.
It has been shown that under the influence of learning, the number of cholinergic receptors increases, i.e. receptors located on the body of the neuron and are responsible for detecting the mediator acetylcholine . In the process of formation of the conditioned reflex, the sensitivity of the corresponding neurons to acetylcholine is increased, which facilitates learning, speeds up memorization and contributes to more rapid retrieval of the memory trace. At the same time, substances that interfere with the action of acetylcholine disrupt learning and reproduction, causing amnesia (memory loss).
It is important to emphasize that the cholinergic system is experiencing a modulating effect on the part of the monoamionergic system. Under the influence of these influences, the activity of cholinergic synapses can change and a chain of biochemical intracellular processes can be triggered, leading to more efficient engram formation.

The value of biochemical studies of memory. Biochemical methods that allow penetration into the sequence of processes playing out in synaptic membranes, followed by the synthesis of new proteins, attract many researchers of memory. On this way, new bright discoveries are expected. It is assumed, for example, that for different types of memory in the near future differences in biochemical processes will be revealed.
Nevertheless, it should be emphasized that intensive biochemical studies have led to a clear reappraisal and autonomization of the cell-molecular level of studying the mechanisms of memory. As S. Rose points out, experiments conducted only at the cellular level are too limited and apparently unable to answer the question - how does the human brain memorize, for example, complex symphonic scores, or extract the data necessary for solving a simple memory? crossword (see Chrestomat. 7.3).
For a more complete knowledge of the specifics of the functioning of memory processes, a transition to the level of complex brain systems is necessary, where many neurons are interconnected by morphological and functional connections. At the same time, psychophysiological studies on healthy people allow studying the processes of processing and storing information, and studying patients with various kinds of amnesia that occurs after brain damage allows them to penetrate deeper into the secrets of memory.
Memory cannot be considered as something static, being strictly in one place or in a small group of cells. Memory exists in a dynamic and relatively distributed form. In this case, the brain acts as a functional system , saturated with various connections that underlie the regulation of memory processes.

Glossary

  1. addictive
  2. hippocampus
  3. neuron ensemble
  4. memory vector
  5. cholinergic neurons
  6. alpha rhythm
  7. refractory period

Questions for self-test

  1. How is addiction different from sensitization?
  2. What are the main steps in the formation of memory engrams?
  3. What centers are included in the system of regulation of memory?
  4. What is the hypothesis of G.Linch and M. Beaudry?
  5. How is the amount of short-term memory and the parameters of the EEG?

 "Is it true that the modal-specific level of memory regulation is provided by the activity of analyzer systems, mainly at the level of the primary and associative cortex areas?"
 
 "not",
 "Yes",
 0.1,
 
 " Choose the correct answer.  
 K. Leshley was a representative:",
  
 "narrow localizationism",
 "antilocalizationism",
 "structuralism",
 "functionalism",
 0.1.0.0,
 
 "Yes",
 "not",
 1.0,
  
 " Choose the correct answer.  
 The main part in the formation of memory nigrams is:",
  
 "neuron bodies",
 "synapses",
 "axons",
 "dendrites",
 0.1.0.0,
 
 " Choose three correct answers.  
 In neurophysiology, the following basic learning mechanisms are distinguished:",
 
 "addictive",
 "sensitization",
 "temporary connection",
 "inbreeding",
 
 " Choose four correct answers.  
 Modal non-specific memory disorders occur when the following brain structures are affected:",
 
 "cerebral cortex",
 "reticular formation of the trunk",
 "diencephalic area",
 "limbic system",
 "hippocampus",
  
 " Choose the correct answer.  
 The experiments of G. Hiden showed that the formation of traces of memory is accompanied by:",
  
 "release of mediators",
 "synthesis of RNA and protein in neurons",
 "activating the amygdala",
 "the formation of new synaptic connections",
 0.1.0.0,
 

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Psychophysiology

Terms: Psychophysiology