Our brains’ impressive capacity to adapt — its plasticity — is a defining feature of being human. In response to sensory inputs, environmental challenges, and even injury, the brain remodels itself and we’re able to learn and change our behavior. Plasticity peaks in childhood, a time when our brains are primed to change in response to experiences.
There are two kinds of plasticity: experience-expectant and experience-dependent.
In experience-expectant plasticity, external inputs during critical developmental windows guide normal development of the brain. For babies, this includes things like hearing language, seeing faces, and being held. Without these inputs, the brain fails to properly mature. Other species need different kinds of sensory inputs. Young finches, for example, must hear adult birds sing in order to learn to sing themselves.
Experience-dependent plasticity is the remodeling of the brain in response to unique life experiences. These changes are not linked to normal patterns of development and can occur throughout life, both during and outside of critical periods. They even happen in adulthood, as our brains are constantly changing in response to our experiences. For example, people who learn to play the violin show greater cortical development in brain regions controlling the left hand.
Understanding how the brain develops can help scientists find treatments for brain disorders throughout the lifespan — from learning and developmental disorders in children, to neurological disease and traumatic injury in adults. If scientists can learn how to manipulate plasticity in the adult brain, it may one day be possible to rewire faulty circuits or heal injured brains.
Adapted from the 8th edition of Brain Facts by Melissa Galinato.
About the Author
Melissa Galinato recently earned her PhD in Neurosciences from the University of California, San Diego. She works as a freelance writer and editor, specializing in neuroscience and mental health topics.
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