Abstract
One of the cognitive and practical challenges of the 21st century is unraveling the mystery of the structure and functioning of the most important and the most complicated organ of the human body, which is the brain. Therefore, it is the subject of research by representatives of many fields of science (e.g., medicine, biology, genetics, psychology, and biochemistry). The objective of this study was to evaluate the cognitive functions of school-age children in Poland. The results of research based on tests that diagnose concentration of attention and memory, including short-term and long-term memory, are described. The research was carried out among students from nine primary schools, including a total of 243 children, their parents, and teachers.