The term "brain plasticity" refers to the brain capability to change in response to the environmental factors. Many of these changes are recorded and stored permanently to be used at a later stage. The concept of brain plasticity is based on assumption that the development of each person's brain is influenced by both physical and psychological experiences. On the systemic level, plasticity is the property of nervous system to adapt, change, self-repair, learn and memorize. This is a common feature of neurons present in each level of nervous system. The concept of brain plasticity therefore has two significant elements: critical periods and changes depending on activity. The notion of critical period means that for some aspects of brain development the time of data reception is crucial and that significant abilities may be lost or limited if no stimulation appears at the right moment. The concept of "activity-dependent learning" shows that changes occurring in brain may also be caused by the influence of psychological, biological or environmental factors. At the basic level organization of cells can change. On higher levels, on dendrites, subsequent branches may ramify, synapses may be formed and the concentration of chemical transmitters may get increased or reduced.