Starting at the Beginning...Early Brain Development

Did you know that when babies are born their brains are not fully developed?  In fact the only part of the brain that is FULLY developed is the lower part of the brain or the brain stem.  This part of the brain is crucial for basic survival.  The key parts of the lower brain are the pons, cerebellum, and the medulla oblongata.  These areas regulate breathing, body temperature, heart rate, and blood pressure.  But interestingly enough, even though the brain is not fully developed, some regions contain all the neurons they will ever have.  Neurons are part of the communication highway and are key in learning new things.  Brain development has thus been defined as:

"In most regions of the brain, no new neurons are formed after birth.  Instead brain development consists of an ongoing process of wiring and re-wiring the connections among neurons.  New synapses between cells are constantly being formed, while others are broken or pruned away."  [Hawley, T. (2000).  Starting smart: How early experiences affect brain development.  Washington DC: Zero to Three, p. 2]

But what about genetics?

"It appears that genetics predispose us to develop in certain ways.  But our interactions with our environment have a significant impact on how our predispositions will be expressed; these interactions organize our brain's development and, therefore, shape the person we become."  [Shore 1997; as cited in Child Welfare Information Gateway (2001).  Understanding the effects of maltreatment on early brain development, p.2]

The debate between nature and nurture may not be a debate at all.  It is more of a partnership between the two than a competition.  This partnership helps define brain development as the young brain develops and learns new skills.

While the lower brain is fully developed, the young brain continues to develop in other very important areas.  The midbrain helps regulate sleep and appetite.  The limbic system is responsible for attachment, sexual behavior, and a range of emotions such as anger and pleasures.

If you can picture it, the brain develops from the back to the front of the head.  The area behind your forehead is known as the prefrontal cortex which is THEE key area that is most important during adolescence.  It is one of the last areas of the brain to fully develop - some estimate in a person's early to mid-twenties.

The prefrontal cortex has been called the "CEO" of the brain or the driver in an uncontrollable car who is responsible for bringing the car back on the right path.  This brain region helps in: logical processing; planning; controlling impulses; anticipating consequences; and balancing risks and rewards.  The prefrontal cortex is closely connected to the limbic system, the emotional system in the brain.  Some researchers also believe that the prefrontal cortex is the location of human conscience, regulating the ability to tell right from wrong.

Tomorrow's blog will explore the relationship between the prefrontal cortex and adolescence.