Mamabare Health

What’s Going on in Your Baby’s Brain?

By Rebecca - September 14, 2018

With a strapping baby boy who is 14 months old today, the newborn phase is still fresh in my mind. We are (bruised) knee-deep in toddler-ing though. There are less and less “baby” traits and this serves a daily reminder that time friggin’ flies! The newborn scent has all but disappeared completely. Xee just started wearing a size 4T winter coat (yes 4T! flashback to 3 sentences ago: he is 14 months old!). The snuggles are still real, as the trending onesies claim, and the nursing is frequent, as my sometimes sore boobs can attest to, but I am slowly (too quickly) losing my baby. (excuse me while I sob) He is being replaced by a sprinting, fumbling, hysterical giant of a child.

As I watch him develop daily, and realize that some mornings he in fact WAKES UP smarter (!) – saying “pasta”, “book” and “dinosaur” for the first time after a good night’s sleep – I am intrigued by all the wizardry taking place behind the curtain. What’s going on behind those bright blue eyes?

100 Billion

A baby’s brain begins to take shape in utero. According to current brain research, an infant is born with roughly 100 billion neurons. A quick wiki lesson: neurons are the electrically charged cells found in brains that process and transmit information throughout your body. Fun fact: a fruit fly has 100,000 neurons. Are you smarter than a fruit fly?

To offer some perspective: 100 billion is a big number. Real big. 100 billion dollars could fill up 1000 crates with 100 dollar bills. There exist at least 100 billion galaxies and 100 billion stars. If you stack 100 billion pennies, it would stretch 98,660 miles high. So yeah, that’s a lot.

700 Synapses

Babies create approximately 700 new brain synapses, or connections between neurons, every second. Every. Single. Second. What amazing thing have I accomplished in the last few seconds? I’m lucky if I remember to add soap to the dishwasher and walk the dog. Wait a minute… I don’t even have a dog.

By 8 months old, babies begin to prune the synapses that have been made in their brains, prioritizing experiences and connections that have been stimulating, practiced over time and reassuring to them. This rapid synaptic growth continues until 2 years of age, at which point synapses continue to be made but at a slower and slower pace.


The brain is so active during childhood that it literally uses 20% of the child’s oxygen reserve. Many of the child’s early experiences serve to enhance infant development: crawling promotes brain organization; infants learn by watching, well before they are able to speak. They do not always need to be physically engaged in order to learn. Modelling is an essential part of the learning experience in the preverbal phase.

As babies do in fact explore objects, as they are exposed to a variety of surroundings and vocabulary, and as they receive comfort to build feelings of safety and security, babies thrive. Their brain is just firing away! Babies are busy categorizing and making sense of the social world around them.


Experience-expectant brain growth takes place when kids are exposed to the ordinary day-to-day happenings that include routines and rituals – in other words, they come to expect these experiences. “Daddy greets me with a smile when I wake up. Mama and Daddy fight about who changes my diaper. Mama nurses me and then I eat Cheerios with my brother. We go for walks and Mama names each thing we see. I always see a dog.”


Experience-dependant brain growth is the result of specific and deliberate learning experiences and includes a refinement of existing brain structures. When exposed to stimulating environments, the baby can become aroused, alert, curious and engaged.

When early learning is rushed, though, or environments become too overstimulating, the brain quickly becomes overwhelmed and the neural circuits can be impaired. The brain then becomes less sensitive to those ordinary experiences and growth is impeded.

Firing Neurons

In 1949, Canadian neuropsychologist Donald Hebb coined the phrase “Neurons that fire together, wire together.” The idea here is that experiences trigger neural activity and serve to form networks.

Repeated experiences trigger the same neurons over and over, in repeating patterns. The importance of experience-expectant and experience-dependant brain growth then becomes clear as we see that what we expose our babies to (or don’t expose our babies to) actually creates long-term wiring.


My son is changing in more ways than just outgrowing his coat size. His brain is doing a lot of work! The wizardry behind the curtain is complex, intricate and vital. But it’s also not as much of a mystery as it used to seem.

Even if I can’t remember to match up socks or empty the diaper genie, the takeaway message from recent brain research is to make sure I provide a reassuring, predictable and safe environment for my baby, adding in doses of stimulating new experiences that will help him grow and refine brain structures, while making sure not to overwhelm his brain and hinder the growth that has already taken place.

…Yeah, this mamabare can do that. Right after my 2nd cup of coffee…