Biochemical theory of memory. Memory
The psychological study of the mechanisms of memory is chronologically older than others. The most widespread are associative theories of memory. Objects and phenomena of reality are imprinted and reproduced not in isolation from each other, but in connection with each other, according to Sechenov, "in groups or rows." The reproduction of some of them entails the reproduction of others, which is determined by the real objective connections of objects and phenomena. Under their influence, temporary connections arise in the cerebral cortex, which serve as the physiological basis for memorization and reproduction. In psychology, these connections were considered as associations. Some of the associations are a reflection of the spatio-temporal relations of objects and phenomena (associations by contiguity), others reflect their similarity (associations by similarity), the third - the opposite (associations by contrast), the fourth - causal relationships (associations by causality).
noted by Aristotle. In the XVIII-XIX centuries. the doctrine of association underlay the so-called associative psychology, which extended the principle of association to all mental phenomena (Hume, D. James, Spencer). A truly scientific substantiation of the principle of associations and the disclosure of their regularities was given by I.M. Sechenov and I.P. Pavlov. According to Pavlov, associations are nothing more than a temporary connection resulting from the simultaneous or sequential action of 2 or more stimuli.
Neural and biochemical theories of memory. The human brain continues to be a mystery in many ways. Its structure is extremely complex. How is the acquisition of new knowledge? Probably, it must be accompanied by some structural or chemical changes in the brain. There are many popular theories, but they are all speculative. Science is still very far from giving a truly accurate and exhaustive description of the way in which the nervous system accumulates information. But these theories are useful milestones on the path to understanding the memory system.
There is almost complete unanimity that persistent storage of information is associated with chemical or structural changes in the brain. Almost everyone agrees that memory is carried out through electrical activity, i.e. chemical or structural changes in the brain must somehow affect the electrical activity. If memory systems are the result of electrical activity, then, therefore, we are dealing with neural circuits capable of realizing memory traces. We know from physiology that the electrical impulse transmitted by a neuron travels from the cell body through the axon to the body of the next one. The place where an axon meets the next cell is called a synapse. There can be thousands of synapses on a single cell body. There are 2 main types of synapses: excitatory and inhibitory.
At the level of the excitatory synapse, excitation is transferred to the next neuron, and at the level of the inhibitory synapse, it is blocked. In order for a neuron to be discharged, a rather large number of impulses may be required; one impulse, as a rule, is not enough. But for simplicity of analysis, let us imagine that a single nerve impulse arriving at an excitatory synapse can cause a new cell response. The simplest circuit providing memory is a closed loop. Excitation sequentially bypasses the entire circle and starts a new one. This process is called reverberation.
The incoming sensory signal causes a sequence of electrical impulses that persists indefinitely after the signal has ceased. The reverberant activity caused by the signal shouldn't really go on indefinitely. Some other mechanism must exist for short-term memory. What causes reverberation to stop? There are several hypotheses. First, a true reverberant circuit would have to be much more complex. Groups of cells are actually arranged in a much more complex way. The background activity of these neurons, as well as the influences from numerous inputs external to the given loop, ultimately disturb the nature of the circulation of impulses. Secondly, another possible mechanism for the termination of reverberation is the emergence of new signals that can actively inhibit the previous reverberation activity. Thirdly, the possibility of some unreliability of the neural circuits themselves is not excluded, the impulse entering one link of the circuit may not always be able to cause activity in the next link and, in the end, the flow of impulses fades. Fourthly, reverberation may stop due to some kind of "chemical" fatigue in neurons and synapses.
Selective electrical activation of a specific neural loop provides short-term memory. How to represent long-term memory in such a scheme? According to one popular theory, repeated electrical activity in neuronal circuits causes chemical or structural changes in the neurons themselves, which leads to the emergence of new neural circuits. This chain change is called consolidation. Trail consolidation takes place over a long period of time. The basis of long-term memory is the constancy of the structure of neural circuits.
Thus, short-term and long-term memory can be associated with the same neural elements, with the difference that short-term memory is the temporary electrical activity of certain neurons, and long-term memory is the permanent structure of the same neurons.
What mechanisms are involved in the consolidation of memory circuits?
There are 2 hypotheses. The first suggests that long-term memory resides in the structure of the protein molecules at each synapse. And nerve information passes through the synaptic cleft by chemical means. According to another point of view, long-term memory may be the result of the emergence of new synapses. This means that whenever new material is learned, physical changes occur in the brain. But microscopic techniques fail to detect these changes, in particular, due to the exceptional difficulty of observing living nerve cells under a microscope. No matter how things happen, one thing is clear that it is the synapse that is the place where the restructuring takes place.
After the discovery of the chemical processes underlying heredity, the idea arose that the same mechanisms could be involved in the processes of memory. Genetic information, specific to each organism, is contained in giant DNA molecules. Its transmission occurs with the help of a molecule of another nucleic acid RNA. And since DNA contains the genetic memory for each individual organism, it is logical to assume that it, or RNA, can also transmit acquired experience.
RNA, enclosed in a specific sequence of organic bases attached to the backbone of the molecule, they serve as templates for protein synthesis. A different sequence leads to the synthesis of different proteins. It can be assumed that this sequence changes as a result of the experience acquired by animals during training. It has now been proven that learning does have an effect on RNA.
The question arises whether the RNA changed as a result of training contains information about the nature of the acquired skill. One way to check is to train animals to perform a specific task, extract RNA from the relevant parts of the nervous system, and try to use this RNA to transfer the knowledge to other animals. This is a very difficult path. Scientists have obtained very conflicting results. The experiments were carried out on planarians (flatworms). If cut in half, each half regenerates into a whole worm. First, the worm was trained to perform a task. Then cut in half, getting 2 identical animals. When the halves were completely regenerated, they began to check.
The hypothesis was as follows: if memory is chemically encoded, then both halves store the task in memory; if memorization is stored in nerve connections - the head ganglia, then the animal that regenerated from the tail will not have the appropriate skills. Under the influence of an electric current, the planaria reflexively contracts. If you combine an electric shock with a bright flash of light, then the animal begins to contract, even if the flash is not accompanied by an electrical stimulus. The result of the test showed that after cutting and regenerating, both halves "remember" the task. This result is amazing. After all, even if information is stored in RNA molecules, how does it reach the tail? That is, the RNA containing the accumulated information is distributed throughout the body of the planaria.
Many chemical studies have also been carried out. Various pharmacological agents were administered in learning situations, either stimulating or inhibiting protein synthesis. These studies have revealed some interesting aspects of memory functioning. For example, memory is most easily impaired by certain substances administered shortly after learning. The longer the interval between training and the introduction of the substance, the greater the dose required to erase traces. The normal functioning of the nervous system depends on a carefully regulated chemical environment, but it is too early to draw any firm conclusions.
The most exciting recent experiments have been attempts to transfer the memory of one animal to another. Planaria willingly eat each other. If one planaria is taught to shrink into light, crush and feed another, then the experience of the first is partially transferred to another worm (D. McConnell's experiment). This caused an unusual public interest and skepticism of science. After all, planaria is a relatively primitive organism. However, in 1966, J. Ungar conducted experiments on memory transfer in rats and mice. In rats, loud noise causes startle. For 9 days they were taught not to flinch. Then, untrained mice were injected with a dialyzed brain homogenate taken from trained donors, after which their response to sound was tested. Mice that received this injection took 1-2 days to suppress the startle response - a striking result when you consider that it takes longer to suppress the startle response in uninjected mice than in rats.
In another experiment, one group of animals was trained to hear a loud sound, and the other to being blown with air (also a startle response). After injections in untrained animals, memory transfer appeared only in relation to the impact to which the donor was accustomed. However, a definitive answer cannot yet be given. Many scientists are rather skeptical about such experiments. If the transfer of information stored in the memory of the brain is possible, then many new mysteries arise regarding the nature of memory. This would mean that specific memory traces are encoded in chemicals that can move freely in the body and be transferred from one animal to another, even from rats to mice.
20. General review of theories of memory: biochemical, physiological, psychological, cybernetic.
Interest in the problem of memory has not dried up for millennia, although there is still no unified and complete theory of memory. Representatives of different sciences intensify their efforts in search of its mechanisms, explain the laws of its functioning, offer a variety of theories, concepts, models. There are several levels of studying the mechanisms and patterns of memory: biochemical level, neurophysiological, psychological and informational.
Psychological theories of memory.
Chronologically, these are the earliest theories. Among them, one of the first is association theory of memory. It arose in line with the most powerful trend in philosophy and psychology of the 18-19th century - associationism. The explanatory principle of all mental formations and the central concept of this theory is association. An association is a connection, a connection. Memory is reduced to associative links created due to the spatial or temporal contiguity of events, their similarity or their difference, contrast.
At the beginning of the 20th century, trends appeared in psychology that emphasize the active role of consciousness in memory processes, while great importance was attached to attention, intention, and comprehension. Based on the criticism of associationism, new concepts and theories of memory arise.
gestaltism- the largest direction in psychology of the 20th century. Another fundamental principle is put forward that underlies the effectiveness of memorization. This is the principle of wholeness, or gestalt. Gestalt means an integral organization, a structure that is not reducible to the sum of its parts. It is the organization and structuring of the material, and not a random set of elements, that is the leading condition for memorizing and reproducing the material. The organization of the material determines and determines the analogous structure of traces in the brain. To explain the selectivity of mnemonic processes, the importance of not only the integrity and organization of the material into a system, but also the role of intentions and needs was emphasized.
Psychoanalysis contributed to the study of the psychology of memory. The role of positive and negative emotions in this process, motives and needs for remembering and forgetting events or information was revealed. Mechanisms of subconscious forgetting (repression) have been discovered.
Representatives behaviorism in their views are very close to the associationists. The only difference was that they emphasized the role of reinforcement in remembering the material. They proceeded from the assertion that for successful memorization it is necessary to reinforce this process with some kind of stimulus.
At the beginning of the 20th century, a semantic theory of memory emerged. The most prominent representatives of this trend were A. Binet and K. Buhler. They argued that the work of memory processes is directly dependent on the presence or absence of semantic connections that unite semantic material into extensive semantic structures.
In the middle of the 20th century, on the basis of a large number of experimental studies, personal theories of memory. These theories singled out a number of factors influencing the course of memory processes. Among the factors were: activity, attention, interest, intention, motivation, awareness of the task, emotional accompaniment.
In the second third of the 20th century, there were activity theories of memory. These theories have received the greatest development in domestic psychology. Within the framework of this theory, memory is considered as a special type of mental activity that has its own operational composition, its own system of actions focused on memorization, processing and preservation of material. The efficiency of memory processes is determined by what a person does with this material in the process of intellectual activity. Active interaction of a person with information, its constant change and contribute to its preservation in the mind.
Cybernetic theories of memory.
In the 1960s-1980s, memory research was developed in psychology within the framework of the informational approach. Here, memory is considered as a process that includes a system of operations for receiving, processing and transforming (quantitative and qualitative) incoming information based on a computer metaphor.
At the same time, it was assumed that information is processed step by step and continuously, and the capacity of the corresponding systems is limited. The term "information processing" covers all aspects of a person's active interaction with information about the world around him. As part of the information approach, the understanding was actively developed and implemented that a person is not a passive communication channel, but he actively processes information, building “internal models, or representations” of the environment. Cognitive processes began to be interpreted by analogy with the processes of information processing in a complex computing device. The connection between internal representations and computer programs was emphasized. Most of the work within the framework of the information approach was aimed at identifying individual processes and types of memory, similar to the blocks for storing and converting information in computing devices.
To explain the features of memorization, preservation, selection and transfer of information into long-term memory, the role of active repetition and other data, researchers proposed memory models in which blocks of information processing in human memory were distinguished. D. Normann proposed a model in which he singled out three consecutive blocks:
1. sensory registers (very short visual memory):
2. primary memory (short-term memory with a limited volume and verbal repetition as a way to store information);
3. secondary memory (long-term semantic memory with a large amount of stored information).
In other words, the first stages in the transformation of sensory information are peripheral types of memory. This is "iconic" memory for sight, and "echonic" for hearing. Then the information enters the verbal short-term memory, where it is stored using hidden or explicit pronunciation. Further, long-term memorization becomes possible. At the same time, the constructive and active nature of cognitive processes unfolds in two phases. First phase - preattention phase, represents coarse information processing. Second phase - phase of focal attention, differs in finer information processing. It is at this phase that verbal coding of information is possible, which serves as a prerequisite for its storage in memory and subsequent reconstruction.
Biochemical and physiological mechanisms of memory are the levels of prepsychic memory, which are the basis, the foundation for the functioning of the mental level.
The physiological mechanisms of memory are considered within the framework of the teachings of I. Pavlov on higher nervous activity, on the formation and development of conditioned reflexes. The establishment of temporary neural connections between nerve centers is an act of memorization at the physiological level. Conditioned reflexes are the mechanisms of formation of the subject's individual experience. The most important condition for the formation of conditioned reflexes is reinforcement. The works of I. Pavlov emphasized the role of conditioned reflexes as a physiological phenomenon, which is based on the fixation of traces in the brain.
How are these bonds formed? Several theories have been proposed to explain the mechanisms of their formation.
Physical theory of memory. It is based on the assumption that the passage of any nerve impulse through a group of neurons leaves behind a physical trace. At the same time, mechanical and electrical changes occur at the points of contact of nerve cells (synapses), expressing the materialization of the trace. These changes facilitate the secondary passage of the nerve impulse along the familiar path.
IN theory of neural models the idea of modeling a perceived object with the formation of a stable spatio-temporal and neural configuration is put forward. The mechanism of storing, storing and reproducing information is the process of formation and subsequent activation of neural models.
Biochemical theories of memory.
Representatives of these theories believe that the mechanisms of memory are based on chemical changes that occur in nerve cells under the influence of external stimuli. Biochemists and geneticists have proven that the transmission of hereditary information is carried out with the help of DNA. This made it possible to put forward a hypothesis about the conditionality of individual memory by the same mechanisms, but the main role here is given to RNA molecules. According to Hiden's hypothesis, nervous excitation changes the composition of RNA. This leads to the formation of a protein corresponding to this excitation. This protein is a material trace, an imprint in which experience is deposited. A similar excitation activates this protein, resonates to the repeated action of familiar stimuli. Biochemical coding allows you to record an unlimited amount of information. The ability of RNA to resonate to specific patterns of familiar stimuli constitutes a biochemical mechanism.
1 The concept of memory
2. Theories of memory
2.1 Psychological theories of memory
2.2 Neural and physico-chemical theories of memory
2.3 Biochemical theories of memory
Conclusion
Bibliographic list
1. THE CONCEPT OF MEMORY
Our mental world is diverse and versatile. Thanks to the high level of development of our psyche, we can do a lot and can do a lot. In turn, mental development is possible because we retain the acquired experience and knowledge. Everything that we learn, each of our experiences, impressions or movements is left in our memory. And a known trace that can persist for quite a long time and, under appropriate conditions, reappear and become the subject of consciousness. Therefore, by memory we understand the imprinting, preservation, subsequent recognition and reproduction of traces of past experience. . It is thanks to memory that a person is able to accumulate information without losing previous knowledge and skills. It should be noted that memory occupies a special place among mental cognitive processes. Many researchers characterize memory as a "through" process that ensures the continuity of mental processes and unites all cognitive processes into a single whole.
MEMORY - the ability to reproduce past experience, one of the main properties of the nervous system, expressed in the ability to store information for a long time and repeatedly enter it into the sphere of consciousness and behavior. Allocate the processes of memorization, preservation and reproduction, including recognition, recollection, actual recollection.
Memory is an integral trace form of reflection. It underlies any mental process. Memory is one of the main forms of organization of mental life.
At present, there is no unified and complete theory of memory in science. A wide variety of hypothetical concepts and models of memory is due to the development of these problems by representatives of various sciences.
2. THEORIES OF MEMORY
2.1 PSYCHOLOGICAL THEORIES OF MEMORY
Among them, the most widespread are the associative theories of memory. In the associative direction, which arose as early as the 17th century, the principle of association is recognized as mandatory not only for the mechanisms of memory, but also for the entire psyche. With any mental formations (thoughts, feelings, perceptions) that have arisen in the mind simultaneously or immediately after each other, an associative connection arises between them (G. Ebbinghaus, 1885). The reappearance of any of the elements of this connection necessarily causes in the mind the representation of all the elements of the association.
Even Aristotle tried to deduce the principles by which our representations can communicate with each other. These principles, later called the principles of association (the word "association" means "connection", "connection"), have become widespread in psychology. These principles are:
1. Association by adjacency . Perceptual images or any representations evoke those representations that in the past were experienced simultaneously with them or immediately after them. For example, the image of our school friend can bring to mind events from our lives that have a positive or negative emotional connotation.
2. Association by similarity. Images of perception or certain ideas cause in our minds ideas that are similar to them in some way. For example, when seeing a portrait of a person, an idea of himself arises. Or another example: when we see an object, it can remind us of some person or phenomenon.
3. Association by contrast. Perceptual images or certain ideas evoke in our minds ideas that are in some respect opposite to them, contrasting with them. For example, by imagining something black, we can thereby evoke in the representation some image of white color, and by imagining a giant, we can thereby evoke the image of a dwarf in the representation. The existence of associations is due to the fact that objects and phenomena are really imprinted and reproduced not in isolation from each other, but in connection with each other (in Sechenov's words, "groups or rows"). The reproduction of some entails the reproduction of others, which is determined by the real objective connections of objects and phenomena. Under their influence, temporary connections arise in the cerebral cortex, which serve as the physiological basis for memorization and reproduction.
The doctrine of association has become widespread in psychology, especially in the so-called associative psychology, which has extended the principle of association to all mental phenomena (D. Hume, W. Jame, G. Spencer). Representatives of this scientific direction overestimated the importance of associations, which led to a somewhat distorted idea of many mental phenomena, including memory. Thus, memorization was considered as the formation of associations, and reproduction as the use of already existing associations. A special condition for the formation of associations is the repeated repetition of the same processes in time.
In the understanding of associationists, mental processes are connected, united with each other themselves, regardless of our awareness of the essential internal connections of the objects and phenomena themselves, the reflection of which these mental processes are.
At the same time, the existence of associative links cannot be denied. However, a truly scientific substantiation of the principle of associations and the disclosure of their patterns was given by I.M. Sechenov and I.P. Pavlov. According to Pavlov, associations are nothing more than a temporary connection resulting from the simultaneous or sequential action of two or more stimuli. It should be noted that at present, most researchers consider associations only as one of the phenomena of memory, and not as its main, much less its only mechanism.
The study of memory was one of the first branches of psychological science where the experimental method was applied. Back in the 80s. 19th century the German psychologist G. Ebbinghaus proposed a method by which, he believed, it was possible to study the laws of "pure" memory, independent of the activity of thinking. This technique is the memorization of meaningless syllables. As a result, he deduced the main curves for memorization (memorization) of the material and revealed a number of features in the manifestation of association mechanisms. So, for example, he found that relatively simple events that made a strong impression on a person can be remembered immediately, firmly and for a long time. At the same time, a person can experience more complex, but less interesting events dozens of times, but they do not remain in memory for a long time. G. Ebbinghaus also found that with close attention to an event, a single experience of it is enough to accurately reproduce it in the future. Another conclusion was that when memorizing a long row, the material at the ends is better reproduced (“edge effect”). One of the most important achievements
G. Ebbinghaus was the discovery of the law of forgetting. This law was derived by him on the basis of experiments with memorizing meaningless three-letter syllables. In the course of experiments, it was found that after the first error-free repetition of a series of such syllables, forgetting at first proceeds very quickly. Already during the first hour, up to 60% of all information received is forgotten, and after six days less than 20% of the total number of originally learned syllables remains in memory.
In parallel with the research of G. Ebbinghaus, research was carried out by other scientists. In particular, the famous German psychiatrist E. Kraepelin studied how memorization proceeds in mentally ill people. Another well-known German scientist, psychologist G. E. Muller, carried out a fundamental study of the basic laws of fixing and reproducing memory traces in humans. It should be noted that at first, the study of human memory processes was mainly limited to the study of special conscious mnemonic activity (the process of deliberate memorization and reproduction of material) and much less attention was paid to the analysis of natural mechanisms for imprinting traces that are equally manifested both in humans and in an animal. This was due to the widespread use of the introspective method in psychology. However, with the development of an objective study of animal behavior, the field of study of memory has been significantly expanded. So, in the late XIX - early XX century. In the early 1900s, studies appeared by the American psychologist E. Thorndike, who for the first time made the formation of skills in an animal the subject of study. The most decisive criticism of the associative theory of memory was carried out from the standpoint of Gestalt psychology (late 19th century). Its main principle is that the analysis of individual elements of the association cannot lead to an understanding of the whole, since the whole is determined not by the sum, but by the interdependence of its individual parts. A single part is only a part and does not give any idea of the whole. Indeed, although a melody performed in different keys evokes perceptually different sensations, it is recognized and remembered as one and the same. It is not the height of the notes that is important here, but their combination, a holistic sound range.
The main concept of Gestalt psychology is the concept of Gestalt (from German Gestalt - image), which means an initially integral structure. Mental activity is characterized by the desire for integrity, completeness. In accordance with this, the organization of the material is recognized here as the basis for the formation of connections, which also determines a similar structure of memory traces in the brain according to the principle of isomorphism, i.e. similarity in form. In Gestalt psychology, the principle of integrity acts as originally given, and the laws of Gestalt (as well as the laws of associations) operate outside and in addition to the will and consciousness of the person himself.
The desire of mental activity for completeness is also manifested in the fact that an unfinished action, an unfulfilled intention leaves a trace in the form of tension in the psyche system. This tension seeks to discharge (in real or symbolic terms). The consequence of the remaining tension is, for example, the effect of an unfinished action, which consists in the fact that the content of an unfinished action is remembered by a person better than the content of a finished one. The lack of integrity, completeness generates not only tension, but contributes to internal conflicts, neuroses.
In other psychological theories of memory, the role of consciousness in the processes of memory is emphasized - the activity of attention and comprehension in remembering and reproducing information. In a number of cases, the activity, consciousness and meaningfulness of memorization are associated only with the highest stages in the development of memory, and in relation to its lower stages, the same concept of association and gestalt is used.
2.2 NEURAL AND PHYSICO-CHEMICAL THEORIES OF MEMORY
There are many theories that support the views of structural or chemical changes in the brain itself when it accumulates lifetime information.
Memory and learning are closely related. Even the simplest forms of learning are based on the fact that some event is remembered. Neuroscientists are now aware of three main types of learning:
1) addiction, or habituation (the body stops responding to a frequently acting stimulus);
2) sensitization (the occurrence of a reaction to a previously neutral stimulus);
3) classical or Pavlovian conditioning.
In habituation and sensitization, the body does not need to create a new association between events or stimuli. In experiments on lower animals, it has been shown that "memorization" in them is provided by structural physico-chemical changes at the cellular level.
The action of memorization mechanisms is much more complicated in classical conditioning, where one cannot do without the involvement of the concept of association. In fact, the conditioned reflex, as an act of forming a connection (association) between new and already fixed content, constitutes the physiological basis of memorization.
All characteristics of the resulting temporary neural connections, and above all the degree of strength, are determined by the nature of the reinforcement, which is a measure of the vital (biological) expediency of this or that action. It is also likely that the passage of any nerve impulse through a group of neurons also leaves a physical trace in the literal sense of the word. The physical materialization of the trace is expressed in electrical and chemical-mechanical changes in synapses, which facilitate the secondary passage of impulses along a familiar path. The simplest neural circuit that provides memory can be represented as a closed loop - excitation goes through the whole circle and starts a new one. This process of long-term circulation of impulses in neural circuits is called reverberation.
The idea of cycles of neural activity is considered by many to be the material substrate of memory. There are a huge number of neural ensembles (each about 100-300 cells). Each of them stores information about some memory object in the form of a stable wave pattern. The more brain neurons are involved in the rhythms of some pulsating ensemble, the higher the probability of understanding the corresponding image.
Two electroencephalographic constants (Livanov, R=0,l and Berger, F=l 0 Hz) in the equations of cognitive psychology quantitatively explain the fundamental psychological features of human information processing, including patterns of perception, memory and speech.
Livanov's constant (a spasmodic change in brain rhythm with a smooth increase or slowdown of external stimuli: a jump in rhythm occurs when there is a discrepancy between the frequencies of the stimulus and the rhythm by 10%) limits the variety of cyclic memory codes, and together with the Berger constant (the frequency of the main brain rhythm - a-rhythm EEG) as well as its speed.
The study of the electrical activity of the brain made it possible to calculate that the possible capacity of long-term memory is 387,420,489 memory units. Each unit is one specific concept or command, i.e. action pattern. For comparison, we can say that the size of the active vocabulary of an ordinary person in their native language is 10,000, and even Pushkin and Shakespeare have less than 100,000 words.
Not all memory units are used and updated at the same time, but only a small number of them. This number serves as a measure of attention span. Due to cyclic fluctuations in the excitability of neural ensembles, long-term memory images, including images of remembered and spoken words, are not updated all at once, but in turn, some more often, others less often. By the frequency of word actualization (for example, in written speech), one can judge the patterns of cyclic neural processes and, conversely, predict the characteristics of speech by the features of neural cycles. If the moments of actualization of different images coincide, then such units of memory have a chance to unite. Thus, a new concept is being developed. This is how learning occurs and acts of creativity are realized.
2.3 BIOCHEMICAL THEORIES OF MEMORY
These theories suggest the formation of new protein substances (neuropeptides and others) during long-term memorization.
First, immediately after exposure to the stimulus, an electrochemical reaction occurs in the nerve cells, causing reversible physiological changes in the cells (short-term memorization), and then, on its basis, the actual biochemical reaction occurs with structural changes in the neuron, providing long-term memory (two-stage nature of the memorization mechanism). Experimentally obtained data on the important role of ribonucleic acid (RNA) and oligopeptides in the implementation of the memory function.
The most exciting experiments in recent years have been attempts to transfer memory from one animal to another ("memory transplant"). If you teach a planarian (flatworm) that light always precedes current, and then kill it and feed it to another planarian, it turns out that the experience gained by the first planarian is partially transferred to the second worm (D. McConnell, 1962). The planarian is a comparatively primitive organism, and it may have special learning mechanisms that are of no relevance to the understanding of memory in higher organisms. However, there is evidence of the success of such an experiment in mice and rats - a "memory transfer" of the developed conditioned reflexes from one individual to another was carried out using injections of the brain homogenate of a previously trained donor animal.
CONCLUSION
There are various theories of memory research. Some of them consider memory from a psychological point of view: as a set of associations that form in the mind - an associative theory; gestalt psychology - the presence of gestalt - an integral system, constantly striving for completion, directing mental activity.
There are many theories that support the views of structural or chemical changes in the brain itself during the accumulation of lifetime information - neural and physico-chemical theories. There are biochemical theories that suggest the formation of new protein substances (neuropeptides and others) during long-term memorization.
Despite many years of research, there is still no complete picture of the physiological mechanisms of memory. The problem of the physiology of memory is an independent problem that physiologists who study the brain are trying to solve. We will focus on that part of the problem that psychologists are exploring.
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Similarity associations are a reflection in the human brain of connections between objects and phenomena that are similar to each other in a certain respect (erroneous perception of a stranger as a friend).
Plan.
Topic 3. Memory, its types and their features.
1. General concept of memory, its processes and functions.
2. Theories of memory and its laws.
3. Types of memory.
4. Individual features of memory.
Key concepts: memory, association, memorization, reproduction, recognition, perseveration, reminiscence, working memory, short-term memory, long-term memory, motor memory.
Think for a moment what our life could turn into if a person were completely devoid of memory. He would not know who he is, where he is, or what date it is today. Even if he was told his name, he still would not remember. Moreover, he would never even realize that he had no memory.
Many psychologists compare human memory with a filing cabinet. This analogy implies that you extract information from the world around you on a topic and then store it in your brain. If you place it in the right place, then in case of need it will be easy for you to remove it.
Memory is the cornerstone of human mental life. Thanks to memory, he can acquire the knowledge, skills and abilities necessary for the activity. Memory is a necessary condition for the mental development of a person. Thanks to memory, the integrity of the “I” of a person is preserved, the unity of his past and present is realized.
I. M. Sechenov said: “A person deprived of memory would constantly be in the position of a newborn, would be a creature incapable of learning anything, mastering anything.” Memory can be defined as the ability to receive, store and reproduce life experience. All living beings have memory, but it reaches the highest level of its development in humans. No other living being in the world has such mnemonic possibilities as he possesses.
Subhuman organisms have only 2 types of memory: genetic And mechanical.
genetic memory manifests itself in the transmission by genetic means from generation to generation of vital biological, psychological and behavioral properties.
mechanical memory acts in the form of the ability to learn, to acquire viable experience, which cannot be preserved anywhere else but in the organism itself and disappears along with its departure from life.
The impressions that a person receives about the world around them leave a certain trace, are stored, consolidated, and, if necessary and possible, reproduced, are called memory.
S. L. Rubinshtein wrote: “Without memory, we would be creatures of the moment. Our past would be dead to the future. The present, as it flows, would irrevocably disappear into the past.
Memory- this is the imprinting (recording), preservation and subsequent recognition of the reproduction of traces of past experience, which allows you to accumulate information without losing your previous knowledge, information, skills.
Traces of memory- this is information about events, objects and impressions that took place in the past.
The study of memory was one of the first sections of psychological science where the experimental method was applied. In the 80s, the German psychologist G. Ebbinghaus proposed a technique with which it was possible to study the laws of pure memory, independent of the activity of thinking - this is the memorization of meaningless syllables, as a result, he deduced the curves of memorization (memorization) of the material. Human memory can be defined as psychophysiological and cultural processes that perform in life functions(these are also memory processes)
Ø memorization
Ø Save
Ø Recognition
Ø playback information
Ø Forgetting
These functions are basic for memory. They are different not only in their structure, initial data and results, but also in the fact that they are developed differently in different people.
original form memorization- the so-called unintentional or involuntary memory, i.e. Memorization without a predetermined goal, without using any techniques. Involuntary memory - this is the memorization of what a person encounters in life - surrounding objects, phenomena, events, people's actions, the content of books read, etc. The best thing to remember is what is of vital importance for a person. But even involuntary memorization is selective, determined by the attitude to the environment.
Arbitrary (deliberate) memorization characterized by the fact that a person sets himself a specific goal - to remember what is planned, and uses special memorization techniques. In the learning process, deliberate memorization often takes the form of memorization, that is, repeated repetition of educational material.
Target set - remember- plays an important role, determining the entire activity of memorization. Memorization is one of the main processes of memory. With rote memorization words, objects, events, movements are remembered exactly in the order in which they were perceived, without any transformations. Mechanical memorization is not economical, requires many repetitions, unlike meaningful memorization. Repetition This is the most important condition for mastering knowledge, skills and abilities. It should be active and varied.
What a person remembers, the brain stores more or less for a long time. Preservation how the process of memory has its own patterns.
The preservation of information and its modification can be judged by the following memory processes - recognition And playback.
Recognition varies in terms of accuracy and completeness. The least degree of recognition is manifested in the “feeling of familiarity”, when a person cannot accurately recognize the feature of an object, but is sure that he is familiar with it. With full recognition, a person accurately assigns an object to a certain category, can accurately name the time, place, and other signs of acquaintance with it.
Recognition any object occurs at the moment of its perception and means that there is a perception of an object that a person has previously formed either on the basis of personal impressions (memory representation) or on the basis of verbal descriptions (imagination representation).
Remembrance- Mental work is easy to remember, but difficult to remember. K. D. Ushinsky wrote: “Persistent recollection is work, and sometimes hard work, to which the child should be accustomed little by little, because the cause of forgetfulness is often laziness to remember the forgotten, and this takes root the bad habit of careless handling of traces of our memory ".
Playback- the image of an object is more difficult than recognition. Reproduction is the activation of previously formed temporary nerve connections in the cerebral cortex. The simplest form of reproduction is recognition.
Recognition is a reproduction that occurs when objects are repeatedly perceived. Recognition is either complete or incomplete. A complex form of reproduction is memory It occurs without a reperception of what is being recreated. Remembrance can be voluntary or involuntary, direct or mediated.
An example of arbitrary memory: remembering the rule when writing a word or sentence when you need to answer a question.
An example of a non-arbitrary memory: an image or information pops up in the mind without a conscious intention. This phenomenon is called perseveration.
Perseveration- This is a representation that has an obsessive character.
Perseveration occurs after repeated perception of certain objects or phenomena, or when there is a strong emotional impact on a person.
The phenomenon belongs to involuntary reproduction reminiscences, or "floating" in the mind of something that could not be remembered immediately after remembering it.
Reminiscence- this is the removal of fatigue of nerve cells, which occurs after the completion of a complex mnemonic task. After some time, this fatigue disappears, and the productivity of playback grows.
Forgetting is the reverse process of memorization. Everything that a person remembers is gradually forgotten over time, especially for those information that is not relevant, not repeated and not reproduced. Forgetting is selective: significant material is forgotten less. Forgetting proceeds especially intensively in the first hours after memorization. Forgotten immediately after perception can be restored after a while. This is the phenomenon of reminiscence (vague memory). Forgetting proceeds faster if the material is not well understood by the person. The speed of forgetting is directly dependent on the volume of the material and the degree of difficulty in mastering it (research by P. I. Zinchenko).
The negative impact of previously memorized material on mastering new data is called proactive(acting forward) interference.
The negative impact of the next activity on the links created in the previous activity can be called retroactive(acting backwards) interference.
Ebbinghaus forgetting curve.
% remembering information
 |
0 1 2 3 4 5 10 15 30 60 90 past
time (days)
A - meaningless material;
B - logical processing;
B - during repetition (the first repetition of information should be 40 minutes after memorization, since after 1 hour 50% of the memorized information remains in memory).
The most common are associative theories of memory. The most important role of associations in memory processes was noted by Aristotle. In the XVIII - XIX centuries. the doctrine of associations was the basis of associative psychology (Hume, D. James, Spencer). A truly scientific substantiation of the principle of associations was given by I. M. Sechenov and I. P. Pavlov.
Definition of I. I. Pavlov:
Associations- this is a temporary connection resulting from the simultaneous or sequential action of two or more stimuli.
Depending on the conditions necessary for their creation, associations are divided into 3 types:
Ø Adjacency associations;
Ø Associations by similarity;
Ø Associations in contrast;
Adjacency Association - it is a reflection in the human brain of connections between objects and phenomena that follow each other in time, or are next to each other in space.
Associations by contrast - this is a reflection in the human brain of objects and phenomena of objective reality, interconnected by opposite signs (high - low, fast - slow).
The theory of neural models is also called physical theory of memory. According to this theory, the passage of any excitation through a certain group of cells (neurons) leaves behind a physical trace, which leads to mechanical and electronic changes in synapses(junction of nerve cells). At the level of the excitatory synapse, excitation is transferred to the next neuron, and at the level of the inhibitory synapse, it is blocked.
The simplest circuit providing memory is a closed loop. Excitation sequentially bypasses the entire circle and starts a new one. Such a process is called reverberation. The reverberant activity caused by a signal does not continue indefinitely. There are a number of reasons to stop it:
1. Genuine reverb circuit must be more complex;
2. new signals appear that can actively inhibit the previous reverberant activity;
3. there is a possibility of unreliability of the neural circuits themselves; the impulse entering one link in the chain may not always be able to cause activity in the next link, and in the end, the flow of impulses fades;
4. reverberation may stop due to some "chemical" fatigue in neurons and synapses.
Consolidation is repeated electrical activity in neuronal circuits that causes chemical or structural changes in the neurons themselves, leading to the emergence of new neural circuits.
CONCLUSION: The biochemical theory of memory is expressed by the hypothesis of a two-stage nature of the memorization process.
At the first step, immediately after the influence of the stimulus, a short-term electrochemical reaction occurs in the brain, which causes reverse physiological processes in the cell. It lasts seconds or minutes and is a short-term memory mechanism.
Second stage arises on the basis of the first - this is actually a biochemical reaction associated with the creation of proteins. It is characterized by the irreversibility of chemical changes in cells; considered to be a mechanism for long-term memory.
DEFINITION: By memory, we understand the imprinting (recording), preservation and subsequent recognition and reproduction of traces of past experience, which allows you to accumulate information without losing your previous knowledge, information, skills.
Memory is the most important mental function, which is a unifying link in the organization of the psyche. It ensures the integrity and unity of the individual.
Memory as a cognitive process
Every cognitive process turns into a memory, and every memory turns into something else. But memory differs from all other mental processes in that it is not directly aimed at reflecting the surrounding world, in contrast, for example, from And .
Memory deals with second-order reflections, which are called representations. Presentation is subjective sensory image of previous perceptions stored in memory. Representations are paler and poorer . This is explained by the fact that perception is always supported by the force of influence on the sense organs of directly perceived objects, and representations do not have such support, since they are built on images of past perceptions. Therefore, in representations, many details of previously perceived objects, phenomena and events are often merged or erased. Representations differ from perceptions also in their variability, inconstancy, the possibility of their "reconstruction" - transformation by the mechanisms of imagination.
Memory, unlike other cognitive processes, does not deal with the connections and relations of objective things themselves, but with the relationship of subjective ideas about things to the existing picture of individual experience. Memory does not produce new knowledge about things, but only reconstructs and organizes what has already been obtained. It constructs new knowledge not through interaction with the things themselves, but through the reorganization of representations that reflect them.
Types and patterns
There are many classifications of memory. The most general basis for the allocation of various types of memory is the dependence of its characteristics on the characteristics of the activity of memorization and reproduction. At the same time, individual types of memory are distinguished in accordance with three main criteria:
- According to the nature of mental activity, predominant in activity, memory is divided into motor, emotional, figurative And verbal-logical;
- By the nature of the objectives of the activity memory is divided into involuntary and arbitrary;
- By the duration of information storage(in connection with its role and place in activity) memory is divided into: instant, short-term, long-term And buffer (operational).
instant memory associated with the inertia of the sense organs. This memory is not arbitrarily manipulated. An image in instant memory does not have constancy - it is an image of sensation, not perception. Instant memory provides a seamless perception of the world.
Short term memory. The information to which attention is drawn is stored here. Information is not stored unchanged - it is processed and interpreted. Short-term memory can be arbitrarily manipulated by repetition or symbolization.
Buffer (Random Access) Memory- an intermediate instance between short-term and long-term memory. Here, information is stored until it can be transferred to long-term memory. Clearing the buffer memory and categorizing the information accumulated during the day occurs during sleep.
long term memory unlimited in terms of the amount and time of storing information. But not always information can be extracted in time. The availability of information is determined by the organization of storage. There are two types of information storage in long-term memory: with random access to information (information is continuously transformed) and without random access (information is stored unchanged).
The speed at which information is retrieved from long-term memory depends on the following factors:
- - class size (the number of alternatives from which the choice is made);
- – the value of information;
- - human attitudes;
- – logical categorization.
Factors that determine the retention of information in long-term memory:
- - familiarity of the material;
- – context;
- – the principle of coding specificity;
- - motivation;
- - deepening into the studied material.
General theories of memory
Representatives of various sciences put forward various theories of memory: physical, chemical, biochemical, physiological, information-cybernetic, as well as a group of psychological theories.
Physical theory of memory. According to this theory, a nerve impulse passing through a certain group of neurons (nerve cells) causes electrical and mechanical changes at the points of their contact and leaves a physical trace behind. These changes provide a secondary passage of the impulse along a familiar path, and thus memorization occurs.
Chemical theory of memory. Supporters of this theory believe that information is remembered due to chemical changes in nerve cells under the influence of stimuli. There is a rearrangement of the protein molecules of neurons, primarily nucleic acid molecules. Deoxyribonucleic acid (DNA) is considered the carrier of genetic memory, and ribonucleic acid (RNA) is the basis of individual memory.
Biochemical theory of memory. The authors of this theory put forward a hypothesis about the two-stage nature of memorization. At the first stage, in their opinion, a short-term (on the order of several seconds) reaction occurs in the brain, which causes physiological changes. These changes are reversible and are the mechanism of short-term memorization. At the second stage - actually biochemical - the formation of new protein substances (proteins) occurs. This stage leads to irreversible changes in nerve cells and is considered the mechanism of long-term memory.
Physiological theory of memory based on the teachings of I.P. Pavlov (http://www.iemrams.spb.ru/russian/pavlovru.htm) about the regularities of higher nervous activity. The physiological act of memorization is based on a conditioned reflex - the act of forming a connection between new and previously fixed content.
Information-cybernetic theorymemory associated with the advent of computer technology and the development of programming, which required the search for ways to accept, process and store information by machines. This required technical and algorithmic modeling of memory processes by analogy with the human brain.
Psychological theories of memory
In this group of theories, several directions can be distinguished: associative, , theory, the meaning theory of memory, . Let's look at each of them briefly:
The achievements of this theory of memory contributed to the development of programmed learning, engineering psychology, its representatives consider behaviorism to be practically the only objective approach to the phenomena under study.
The views of the supporters of behaviorism and associationists on the problem of memory turned out to be very close. The only significant difference between them is that Behaviorists emphasize the role of exercises in memorizing material and pay much attention to the study of how memory works in the learning process..
