Abstract
The development of the human brain, both before and after birth, progresses through a sequence of active and sensitive periods for various brain functions. By the time of birth, 86 billion neurons already exist and have begun rapid networking through synaptogenesis, by which each neuron can connect to thousands of other neurons. In this paper, we explore how the brain is primarily programmed through the synaptic pruning process to manage its many functions, pinpointing the active and sensitive periods of this programming. The brain functions are divided into five sensory functions, as well as emotional, motor, cognitive, learning, and memory functions. Each of these functions has specific active development times, known as sensitive periods (also critical periods). Since the programming relies on experiential training of the firing pathways using sensor activation signals, the outcome is heavily dependent on the sensory signals the brain receives from its environment. Therefore, understanding how to interact with and care for a baby during these distinct sensitive periods is vital. If the environment is stable and caregivers act consistently, the baby’s brain receives regular and repetitive training material, ideally strengthening and accelerating the permanent programming of the brain.
