One-sided and double-sided (reversible) Interhemispheric boards or labyrinths (with two wooden styluses and marbles included) are educational toys designed to train both hemispheres of the brain. As a result of the passage labyrinths at the same time with different hands, improved the interaction and synchronization of the left and right hemispheres of the brain. HOW TO USE? The child trace stylus, finger or takes marbles (balls) and inserts it at the beginning of the labyrinth, passes the entire labyrinth, first only with his right hand, then with his left hand. Both hemispheres of the brain are involved in the work and they are synchronized.