## 3 Materials and Methods
### About the Reproduction of Subconscious Movements When Typing Text on a Keyboard
#### 3.1.2 Areas of the Brain Involved in Reproducing Movements When Working with a Keyboard  
The problem of the hierarchical organization of human movements was considered in the works of the Russian physiologist [PERSON]. In the same work, a theory of the levels of movement construction was presented. The levels are understood as morphological sections of the nervous system, each of which corresponds to its own type of movement. Five levels were identified (Figure 2) [25]:  
* The A level is responsible for muscle tone. A typical independent manifestation of this level is the body trembling from cold or fear.
* At the B level, the work of \"temporary ensembles\" (synergies) is organized. This level takes part in the formation of movements of a more complex type without taking into account the characteristics of external space (stretching, involuntary facial expressions, and simple reflexes).
* At the C level, information about external space coming from the senses is taken into account. This level is responsible for constructing movements adapted to the spatial properties of objects--running, waving arms, etc.
* The D level is responsible for organizing interaction with objects. At this level, data on the main physical characteristics of surrounding objects are taken into account, and the motor programs used are made up of flexible, interchangeable links.
* At the E level, \"intellectual\" motor acts are formed (for example, speech or writing). Moreover, it can be called \"objectless\" because movements are determined by anabstract meaning (when a person writes a letter, he thinks about the meaning of the letter, and not about the mechanical process of writing itself).  
When typing on a keyboard, the extrapyramidal system conducts nerve impulses to support the position of the back, arms and shoulders to allow typing. The pyramidal system conducts motor impulses for coordinated and independent movements of the fingers. Learned voluntary movements are activated by pyramidal cells in the motor area on the opposite side of the cerebral cortex and by impulses from the cerebellum. Movement intentions are translated into specific programs by areas of the premotor and association cortex (frontal and parietal areas), the basal ganglia, and lateral part of the cerebellum. The thought to initiate a specific movement is translated into detailed neural programs by the basal ganglia, premotor cortical areas (Brodmann areas 5, 6, 7, as seen in Figure 3), and the lateral cerebellum. In the primary motor cortex (Brodmann area 4, as seen in Figure 3), these instructions are decoded and executed. This area of the cerebral cortex contains centers that control muscle groups belonging to the opposite side of the body. The intermediate zones of the cerebellar hemispheres receive two types of information: at the start of the movement from the motor cortex about the sequence of the movement plan, and from the peripheral parts of the body (limbs) about the nature of the movement being performed. After comparing this information, the cells of the deep intermediate nucleus send corrective signals to the motor cortex. There are several feedback loops for controlling voluntary movements. One of them is the visual system. When typing, individual zones of the frontal lobe, supplementary motor area, parietal area, and other regions are activated. Movements that include rapid sequences of muscle contractions cause an increase in blood flow in the supplementary motor cortex [26].  
Figure 2: Levels of movements and the involvement of different parts of the brain in their reproduction.