Higher mental functions in children often initially arise as separate structures: speech, visual perception, attention and memory. However, as they develop, they begin to integrate into functional systems. This integration allows the child to consistently and flexibly use these functions to solve problems, learn and regulate behavior. Any delay in this process (the so-called “integration delay”) can lead to learning difficulties or to multi-level functional disorders (not necessarily a permanent impairment of higher mental functions). The basic idea is that some disorders are not the result of a complete loss of function, but rather of a delay in the interconnection and coordination between different functional systems. This highlights the importance of specific diagnosis and early intervention aimed at strengthening the link between these functions to ensure balanced and inclusive development.