Early Brain Development

Science has identified the period from conception to age 6 as the most critical period of development over the human life span. During this time, the developing brain is highly sensitive to its surroundings, and grows and adapts in response to its environment.

  • Did you know….90% of brain growth occurs by age 6.

Parents and caregivers play the most important role in a child’s life by providing stimulation for their active young minds, and by creating a nurturing and loving environment that enables children to thrive. Children benefit considerably when society as a whole supports families, through cohesive neighbourhoods and communities that provide opportunities for families with young children to thrive.

  • Did you know…back-and-forth interactions between caregiver and child are key to a child’s brain development.

When infants, toddlers, and children actively observe and explore their surroundings, they are doing important work to prepare their brains for a lifetime of learning. During this early stage, children’s brains are most engaged through active communication and through interactive play-based learning. Expensive toys are not necessary – what kids need most is your love, attention, and imagination.

  • Did you know…children learn best through play and exploration.

Sensitive Periods in Early Brain Development

During the first few years of life, infants and children’s brains develop a foundation of knowledge through which to understand the world around them. This knowledge and understanding is critical to developing higher, more complex brain functions in later life.

Key sensitive periods occur when children develop:

The brains of infants and young children experience key ‘sensitive periods’ during which their brains are uniquely ready and able to learn certain types of information, as shown in the image above.

  • Sensory Perception (develop binocular vision, depth perception, recognize familiar sounds and voices, learn about surroundings through objects’ visual appearance, sound, feel, taste, and smell)
  • Language (recognize that words have meaning, express needs by vocalizing, learn basic sounds of primary language(s) spoken in home, learning written language, etc…)
  • Higher Cognitive Functions (using selective attention to filter out competing stimuli, understanding and engaging in social interactions, understanding concepts, processing more complex information, developing memory, understanding that oneself and other individuals have thoughts, feelings and desires that influence their behaviour, perceptions, etc…)
Birth – 2 Years2 – 4 Years4 – 5 Years
VisionPeer social skillsNumbers
LanguageConceptualizationPeer social skills
Emotional controlNumbersConceptualization

“Higher levels of brain circuits depend on precise, reliable information from lower levels in order to accomplish their function. Sensitive periods for development of lower level circuits ends early in life. High level circuits remain plastic for a longer period.”
(Knudsen 2004)

The foundation of knowledge and abilities built during early childhood is critical as it provides children with the basis for successful lifelong functioning. During early childhood the human brain is the most plastic it will ever be, and its sensitivity to learning is heightened.

Children who do not have adequate opportunities to learn and develop during sensitive periods, or whose development is otherwise affected, can still learn the same skills and abilities at a later time – it just takes a little longer and requires more effort to learn than during the earliest years.

Experience-Based Brain Development

Every aspect of the outside environment that a child experiences plays a role in shaping the brain development. At birth babies are born with virtually all the neurons they will ever have. Yet, their brain triples in size during their first 3 years of life. This tremendous growth occurs as the brain builds ‘neural pathways’ that connect neurons to one another (McCain, Mustard & Shanker, 2007).

Pathways are formed based on stimulation the child receives through everyday experiences. As experiences become familiar, the brain uses already-established pathways to process the information. Using these pathways reinforces them, much like making a new path in the forest. When a path is well-traveled, it becomes a more permanent feature of the forest and is easier to follow. The more often pathways are used, the stronger they become and the less likely they are to fall into disrepair.

The saying, “use it or lose it,” is very accurate in terms of how the brain works. Synaptic connections that are used the most often are maintained and strengthened, while those that the brain uses less often become damaged or die. This natural and important process is known as ‘synaptic pruning’.

By the time a child reaches adolescence, major synaptic pruning has occurred. This is a natural and important process through which the brain maintains and strengthens the neural connections that are most used, and are presumably most important for the individual to survive and thrive in their environment (Rima Shore, 1997).

The brains of children who experience chronically stressful or dangerous environments during their early development adapt to these circumstances. Because the brain uses neural connections that monitor for, anticipate, and prepare for signs of danger, these neural connections are strengthened resulting in the individual having heightened lifelong sensitivity to stress and signs of danger.

Research has also shown that children who experience neglect in multiple domains of their development (ex. language, touch, and social interaction) during early childhood have fewer and less dense neural connections than children whose development is supported by rich and nurturing early environments (Perry and Pollard, 1997).

During these years, it is important to provide quality environments – whether they be at the grocery store, in a park, in non-parental care, in a child care setting, or in a preschool/early learning setting. Quality environments can generally be described as those in which children are engaged, stimulated, are nurtured.

Research suggests that the nurturing environments are those which use rich and interactive language, encourage exploration, in which basic skills are mentored, rehearsed and extended, in which developmental advances are celebrated, are equitable, and in which children do not experience inappropriate discipline or punishment (Ramey and Ramey, 1998).

In terms of the amount of knowledge and abilities that young children learn and their tremendous brain activity, young children are geniuses. Never again is the human mind be so primed and ready to learn a new language, new physical abilities, or develop the foundation for strong social skills.

While parents want to do the best for their children, they cannot do it all on their own – it really does take a village to raise a child. Ensuring healthy child development depends upon support for young children and their families from the community as a whole and from all levels of government. Raising a population of children who are happy, healthy, and productive is key to Canada’s ongoing social and economic success.