A fundamental theory of the origin and development of higher mental functions was developed by Lev Semenovich Vygotsky (1896-1934). Relying on the ideas of comparative psychology, L.S. Vygotsky began his research where comparative psychology stopped before the unsolvable for her questions: she could not explain the phenomenon of human consciousness. The fundamental idea of Vygotsky is about the social mediation of a person’s mental activity. The tool of this mediation is, in Vygotsky’s opinion, a sign (word).Vygotsky described the first version of his theoretical generalizations concerning the laws of development of the psyche in ontogenesis in the work “Development of the VPF.” In this work, a scheme was presented for the formation of the human psyche in the process of using signs as a means of regulating mental activity.In the mechanisms of brain activity LS. Vygotsky saw dynamic functional complexes (“The Development of Higher Psychic Functions”, 1931).“Man in the process of his historical development rose to the creation of new driving forces of his behavior: thus, in the process of a person’s social life, his new needs arose and developed and his natural needs underwent profound changes in the course of his historical development.”A person has 2 lines of development: 1) natural; 2) cultural (historical).The natural line of development is the physical, natural development of the child from the moment of birth.When there is communication with the outside world, a cultural line of development emerges.1. NPF – natural: sensations, perception, children’s thinking, involuntary memory.2. WFD – cultural, social; – the result of historical development: abstract thought, speech, arbitrary memory, voluntary attention, imagination.VFF – complex, life-forming mental processes, social in origin. Distinctive features of the VPF are their indirect character and randomness.The use of the sign, the word as a specifically human psychic regulator, reorganizes all the higher mental functions of man. Mechanical memory becomes logical, associative flow of representations – productive thinking and creative imagination, impulsive actions – by actions arbitrary.The VFT originated with the help of a sign. A sign is an instrument of mental activity. This is an artificially created human stimulus, a means to control your own behavior and the behavior of others.A sign, as a purely cultural means, arose and is used in culture.The history of the development of mankind is the history of the development of the sign. The more powerful the development of signs in generations, the more developed the VFR.Painting has a sign system, because it, as a sign, reflects the vision of the world (for example: a rock drawing, a pictographic letter – a conventional image of the word).Signs can be called gestures, speech, notes, painting. The word, both spoken and written, is also a sign. Little children are already beginning to learn the signs, which are expressed in a drawing. The child appropriates everything that has been worked out by the person (psyche). The history of the development of the child resembles the history of human development Assignment of the psyche goes through an intermediary.Vygotsky tries to combine the natural and historical lines.Historical study means the application of the category of development to the study of the phenomenon. All the modern theories treated children’s development from the biological point of view (the transition from the social to the individual).The RPF is possible initially as a form of cooperation with other people, and subsequently becomes individual (example: speech is a means of communication between people, but in the course of development it becomes internal and begins to perform an intellectual function)A person does not have an innate form of behavior in the environment. Its development occurs by appropriation of historically worked out forms and methods of activity. Vygotsky postulated a structural analogy between objective and internal mental activity. The inner plane of consciousness began to be understood in domestic psychology as an actively mastered external world.Vygotsky first passed from the assertion about the importance of the environment for development to the identification of a specific mechanism of the influence of the environment, which actually changes the child’s psyche, leading to the appearance of specific for the person higher mental functions. Such a mechanism Vygotsky considered the interiorization of signs – man-made incentives-tools designed to control his and others’ behavior.Speaking about the existence of natural and higher mental functions, Vygotsky concludes that the main difference between them is in the level of arbitrariness. In other words, unlike natural mental processes that can not be regulated by humans, people can consciously control higher mental functions.The scheme of mental processes in the view of Vygotsky looks like thisUnlike stimulus-means, which can be invented by the child himself (a stick instead of a thermometer), the signs are not invented by children, but are acquired by them in communication with adults. Thus, the sign appears first in the outer plane, in terms of communication, and then goes into the internal plan, the plan of consciousness. Vygotsky wrote that every higher mental function appears on the stage twice: once as an external one – an interpsychic one, and the second as an internal one – intrapsychic.Moreover, signs, being a product of social development, bear the imprint of the culture of the society in which the child grows. Children learn signs in the process of communication and start using them to control their inner psychic life. Due to the internalization of signs, the sign function of consciousness is formed in children, the formation of such actually human mental processes as logical thinking, will, speech is taking place. In other words, the interiorization of signs is the mechanism that forms the psyche of children.Consciousness must be studied in an experimental way, therefore it is necessary to bring together the VPF, the cultural development of behavior, mastering one’s own behavioral processes.One of their most important characteristics is mediation, that is, the availability of the means through which they are organized.For higher mental functions, the availability of an internal means is in principle. The main way of the emergence of higher mental functions is internalization (transfer to the internal plan, “rotation”) of social forms of behavior into a system of individual forms. This process is not mechanical.Higher mental functions arise in the process of cooperation and social communication – and they also develop from primitive roots on the basis of the lower ones.The sociogenesis of higher mental functions is their natural history.The central point is the emergence of symbolic activity, the mastery of a verbal sign. It is he who acts as a means, which, by becoming internal, radically transforms the psychic life. The sign first acts as an external, auxiliary stimulus.The higher mental function in its development passes through two stages. Originally it exists as a form of interaction between people, and only later – as a completely internal process. This is referred to as the transition from the interpsychic to the intrapsychic.At the same time, the process of the formation of higher mental function is extended for a decade, arising in speech communication and ending in a full-fledged symbolic activity. Through communication, a person takes possession of the values of culture. By mastering signs, a person becomes attached to a culture, the main components of his inner world are values (cognitive components of consciousness) and meanings (emotionally motivational components).Vygotsky argued that mental development does not follow the maturation, but is due to the active interaction of the individual with the environment in the zone of his closest mental development. On these foundations, the national psychological school was formed.The driving force of mental development is learning. Development and learning are different processes. Development is the process of the formation of a person or person, accomplished by the emergence of new qualities at each level. Training is an internally necessary moment in the process developed by the child of the historical features of mankind.He believes that learning should “lead” the development, this view was developed by him in developing the concept of “zone of proximal development.” Communicating a child with an adult is by no means a formal moment in Vygotsky’s concept. Moreover, the path through the other turns out to be central in development.Training is, in effect, a specially organized communication. Communication with an adult, mastering the methods of intellectual activity under his leadership, as if set the immediate prospects for the development of the child: it is called the zone of proximal development, in contrast to the current level of development. Effective is the training, which “runs ahead” of development.