A foundational principle of brain development is that neural systems organize and become functional in a sequential manner. Furthermore, the organization of a less mature region depends, in part, upon incoming signals from lower, more mature regions. If one system doesn’t get what it needs when it needs it, those that rely upon it may not function well either, even if the stimuli that the later developing system needs are being provided appropriately. The key to healthy development is getting the right experiences in the right amounts at the right time.
