Which statement is one a researcher should make when explaining facts about brain development?

The early years of a child’s life are very important for later health and development. One of the main reasons is how fast the brain grows starting before birth and continuing into early childhood. Although the brain continues to develop and change into adulthood, the first 8 years can build a foundation for future learning, health and life success.

How well a brain develops depends on many factors in addition to genes, such as:

• Proper nutrition starting in pregnancy
• Exposure to toxins or infections
• The child’s experiences with other people and the world

Nurturing and responsive care for the child’s body and mind is the key to supporting healthy brain development. Positive or negative experiences can add up to shape a child’s development and can have lifelong effects. To nurture their child’s body and mind, parents and caregivers need support and the right resources. The right care for children, starting before birth and continuing through childhood, ensures that the child’s brain grows well and reaches its full potential. CDC is working to protect children so that their brains have a healthy start.

The importance of early childhood experiences for brain development

Children are born ready to learn, and have many skills to learn over many years. They depend on parents, family members, and other caregivers as their first teachers to develop the right skills to become independent and lead healthy and successful lives. How the brain grows is strongly affected by the child’s experiences with other people and the world. Nurturing care for the mind is critical for brain growth. Children grow and learn best in a safe environment where they are protected from neglect and from extreme or chronic stress with plenty of opportunities to play and explore.

Parents and other caregivers can support healthy brain growth by speaking to, playing with, and caring for their child. Children learn best when parents take turns when talking and playing, and build on their child’s skills and interests. Nurturing a child by understanding their needs and responding sensitively helps to protect children’s brains from stress. Speaking with children and exposing them to books, stories, and songs helps strengthen children’s language and communication, which puts them on a path towards learning and succeeding in school.

Exposure to stress and trauma can have long-term negative consequences for the child’s brain, whereas talking, reading, and playing can stimulate brain growth. Ensuring that parents, caregivers, and early childhood care providers have the resources and skills to provide safe, stable, nurturing, and stimulating care is an important public health goal.

When children are at risk, tracking children’s development and making sure they reach developmental milestones can help ensure that any problems are detected early and children can receive the intervention they may need.

Learn more about supporting early childhood experiences:

A healthy start for the brain

To learn and grow appropriately, a baby’s brain has to be healthy and protected from diseases and other risks. Promoting the development of a healthy brain can start even before pregnancy. For example, a healthy diet and the right nutrients like sufficient folic acid will promote a healthy pregnancy and a healthy nervous system in the growing baby. Vaccinations can protect pregnant women from infections that can harm the brain of the unborn baby.

During pregnancy, the brain can be affected by many types of risks, such as by infectious diseases like Cytomegalovirus  or Zika virus, by exposure to toxins, including from smoking or alcohol, or when pregnant mothers experience stress, trauma, or mental health conditions like depression. Regular health care during pregnancy can help prevent complications, including premature birth, which can affect the baby’s brain. Newborn screening can detect conditions that are potentially dangerous to the child’s brain, like phenylketonuria (PKU).

Healthy brain growth in infancy continues to depend on the right care and nutrition. Because children’s brains are still growing, they are especially vulnerable to traumatic head injuries, infections, or toxins, such as lead. Childhood vaccines, such as the measles vaccine, can protect children from dangerous complications like swelling of the brain. Ensuring that parents and caregivers have access to healthy foods and places to live and play that are healthy and safe for their child can help them provide more nurturing care.

Learn more about the recommended care:

What does CDC do to support early brain health?

CDC is committed to supporting early brain health through evidence-based programs and partnerships within communities. Below are just a few examples of CDC programs that support early brain health:

Brains are built over time, from the bottom up. The basic architecture of the brain is constructed through an ongoing process that begins before birth and continues into adulthood. Simpler neural connections and skills form first, followed by more complex circuits and skills. In the first few years of life, more than 1 million new neural connections form every second.* After this period of rapid proliferation, connections are reduced through a process called pruning, which allows brain circuits to become more efficient.

Brain architecture is comprised of billions of connections between individual neurons across different areas of the brain. These connections enable lightning-fast communication among neurons that specialize in different kinds of brain functions. The early years are the most active period for establishing neural connections, but new connections can form throughout life and unused connections continue to be pruned. Because this dynamic process never stops, it is impossible to determine what percentage of brain development occurs by a certain age. More importantly, the connections that form early provide either a strong or weak foundation for the connections that form later.

The interactions of genes and experience shape the developing brain. Although genes provide the blueprint for the formation of brain circuits, these circuits are reinforced by repeated use. A major ingredient in this developmental process is the serve and return interaction between children and their parents and other caregivers in the family or community. In the absence of responsive caregiving—or if responses are unreliable or inappropriate—the brain’s architecture does not form as expected, which can lead to disparities in learning and behavior. Ultimately, genes and experiences work together to construct brain architecture.

Cognitive, emotional, and social capacities are inextricably intertwined throughout the life course. The brain is a highly integrated organ and its multiple functions operate in coordination with one another. Emotional well-being and social competence provide a strong foundation for emerging cognitive abilities, and together they are the bricks and mortar of brain architecture. The emotional and physical health, social skills, and cognitive-linguistic capacities that emerge in the early years are all important for success in school, the workplace, and in the larger community.

Toxic stress weakens the architecture of the developing brain, which can lead to lifelong problems in learning, behavior, and physical and mental health. Experiencing stress is an important part of healthy development. Activation of the stress response produces a wide range of physiological reactions that prepare the body to deal with threat. However, when these responses remain activated at high levels for significant periods of time, without supportive relationships to help calm them, toxic stress results. This can impair the development of neural connections, especially in the areas of the brain dedicated to higher-order skills.

*The number “more than 1 million new neural connections per second” updates an earlier estimate of 700-1,000 new connections (which still appears in some of the Center’s printed publications, but as of April 2017 has been updated online and in all PDFs). All of these numbers are estimates, calculated in a variety of different ways, but we are making this change in our materials after a careful review of additional data that were called to our attention. The Center is deeply committed to a rigorous process of continuous refinement of what we know and an ongoing pledge to update that knowledge as additional data become available.