The first expression of brain activity is crying for food…
The first three years of life are essential for brain development and set the foundation for a healthy brain throughout life. While genetic factors have some impact on your baby’s cognitive development, the child’s experiences are what really define the evolution of most of brain structures.
The first signs of baby brain development
The first expression of brain activity is crying for food and during the first months of life this evolves into more complex behaviors such as babbling, moving and responding to visual stimuli. The newborn’s brain already has all the instinctive capacities needed for survival wired in, but the baby does not yet have full perception of the world around him. Cognitive development is what allows the baby to mature more complex skills such as thinking, motor coordination, memory and language.
How the brain is made up
The brain is divided in 3 major parts, the cerebellum, the brain stem and the cerebrum. The cerebrum is divided in two parts that mirror each other, the right and the left hemispheres. Due to its wrinkled appearance, the cerebral cortex (the outermost layer of the cerebrum), can be divided in distinct physical and functional regions, the lobes. Each hemisphere has four lobes and components of the limbic system, and is attached to the cerebellum and brain stem, which are responsible for distinct functions:
- Frontal lobe. This area is responsible for voluntary behaviors, impulse control, emotions and interpreting of information. The frontal lobe development is more pronounced between six and twelve months of age. The development is visible when your baby starts to talk and walk, since both actions rely on the frontal lobe commands. The foremost part of the frontal lobe is the prefrontal cortex, which only fully matures in adolescence, and is responsible for motivation, attention, and goal-directed behavior.
- Parietal lobe. This area integrates sensorial information coming from other parts of the body, like taste, visual cues and touch. As the parietal lobe develops, the baby will get hand-eye coordination and the ability to recognize objects. It is important to present new stimuli such as smells, textures and objects to your baby in order to stimulate the development of this brain region.
- Occipital lobe. This lobe is responsible for vision recognition, as it receives input directly from the eyes and translates the information into neuronal signs that are conveyed in other parts of the brain. In newborns, vision is poorly developed and they can only see a 20 to 40 centimeters distance. Even in this range they can only distinguish light, movement and general shapes. Continued visual stimulation of your baby with colorful objects from the first month of age onwards is essential for proper development of neuronal pathways in the occipital cortex. At 8 months of age babies can already see perfectly.
- Temporal lobe. This area controls hearing and understanding language. It is also involved in smell, learning, emotion and memory. It is important for the development of social skills and perception of other people’s expressions, eyes and faces. The sense of hearing is the only sense that is fully developed before birth, since the baby can respond to noises even from inside the uterus. Smell also develops early, newborns can react to smell from the first day and recognize the smell of their mother.
- This area is part of the limbic system, and is involved in spatial learning and memory formation.
- This is another area of the limbic system, and is responsible for the control of deep sleep, stress responses and release of hormones.
- This small structure inside the cerebrum is responsible for fear response and triggering of fight or flight behavior.
- This is the area that controls motor and sensory abilities. The main function is to coordinate sensory information in order to allow balance and coordination during movement. It also works in the development of language and processing of social cues.
- This area connects the spinal cord to the upper brain and controls the baby’s involuntary movements and reflexes such as, respiratory, heart and digestive system function. It is also the area that commands basic behaviors that are already developed at birth, including suckling, crying and startling. The brainstem communicates with the amygdala to develop appropriate emotional responses, for example crying in the presence of fear .
However, this definition of brain regions’ functions is simplistic and the brain evolves as a whole, in which all the different parts interact with each other and convey the information necessary for all our actions. The major developments that occur in the first three years of life make it a time where the environment shapes the way the brain works for life. The children’s early experiences have long-lasting effects that can be seen in the patterns of brain activity.
The brain of a newborn already has all the neurons necessary for life, since only a small amount of neurogenesis occurs after the brain develops in the womb. Therefore, the determining thing for cognitive development is not the number of neurons but the connections formed between them. These connections form in excess during the first years of life and by age three the brain has twice as many connections than the ones it really needs. Then, it undergoes a process of exclusion until adolescence is complete and the adult brain is fully formed.
It is the things that the baby experiences in the first three years that direct the connections formed by stimulating neural activity. The more the environment in which the baby is raised stimulates the brain, the more it develops connections that are likely to maintain through adulthood. This also means that babies are vulnerable to persistent negative influences during the first years of life.
During the first year of life a baby’s brain reaches eighty percent of the volume it will have as an adult by doubling the size it had at birth. Newborns, despite having poor visual acuity can already discriminate voices, faces and expressions. The size of the cerebellum triples in the first year, leading to the development of motor skills. The recognition memory is also improved by the development of the hippo campus, and the frontal and temporal lobes mature to allow language processing and speech.
The stages of development
The language that the baby hears in the first months of life influence the way that the brain forms connections and favors the learning of that language. The baby also develops recognition, the ability to know that there is a connection between his actions and a result.
In the first three months, the baby does not have recognition skills and, although he can recognize you mostly by smell, he cannot distinguish easily between strangers. At six months he understands physical boundaries and categories of objects, recognizing them by shape, color and texture. By nine months the baby can crawl and plan his actions, he recognizes his own name and copies your actions frequently. By the end of the first year he might be able to say his first words and his babbling starts making more sense .
During the second year of life, the language skills of the baby develop by forming more and more synapses, which translates in a sudden spike in language abilities. The sense of self also evolves during this period which allows the recognition of a mirror image and his own emotions. You may notice that he is a lot more curious as he starts exploring the surroundings and searching for his favorite toys. The baby now has perception of the things that hurt him but not that he can cause pain to others.
In the third year of life, the child is able to perform more complex cognitive tasks due to the development of the pre frontal cortex. This allows the child to connect events as cause and effect and link past with present.
You can help your baby’s cognitive development simply by stimulating him every day. Toys are a good tool when appropriate for his age, but be aware that too many toys can distract him instead of developing object recognition skills. Just keep in mind that not all babies develop at the same pace and some milestones may be reached before others. You just have to be patient and keep trying to understand what he likes most, in order to help him develop a certain skill. You can also rely on your pediatrician if the baby has some worrying delays in development.