There are optimal times when certain areas of the brain are most ready to develop. Researchers refer to this time of readiness as a sensitive period in development.
Sensitive periods open a window of opportunity where experiences have a greater impact on certain areas of brain development. During sensitive periods, the brain is most likely to strengthen important connections and eliminate unneeded ones in a specific part of the brain.
Growth in that area is still possible after the sensitive period, but it is not as easy or automatic. Our brains are flexible and adaptable, and many abilities can develop later in life if important experiences are missed in the early years. Making up for lost experiences, however, is much more difficult, takes much longer, and can require intensive intervention.
An example of a sensitive period occurs in vision development. Infants are born with the basic ability to see (unless their vision is impaired by prenatal damage or genetic defects), but a newborn’s vision is not as good as the vision of an 8-month-old. The opportunity to look at people and things in the early months strengthens the brain connections that control vision.