
For much of the 20th century, scientists believed that the adult human brain was largely fixed. According to this view, the brain developed during childhood, settled into a stable form in early adulthood, and then resisted meaningful change for the rest of life.
Today, the concept of neuroplasticity, the brain’s ability to change its structure and function in response to experience, is a central principle of brain science. The brain can change throughout life, but not without limits, not instantly and not effortlessly.