OverviewSince the seminal work of Jean Piaget on the relation between knowledge and general biology, researchers have started to understand the basic neurocognitive processes in the unfolding of human development. In particular, recent dynamic growth models illuminate the complex, interrelated changes that take place during brain growth, cognitive development, and learning. Neurocognitive development should be conceived not as a ladder of successive stages but as a complex network of interactions and attractors, convergent and divergent paths, nested cycles, stabilities and instabilities, progressions and regressions, clusters of discontinuities and stable levels of performance. Cycles of cortical development and cycles of cognitive performance seem to be related. In particular the relationship becomes most visible with optimal functioning of the cognitive system, such as when a good teacher or textbook supports a student's performance.