Brain Development in Adolescence

Instructor: Emily Cummins
The adolescent years are an important time for the development of the human brain. In this lesson, we'll talk about some of the important changes that the brain undergoes during this period of our life.

Brain Development in Adolescence

We tend to think about growth and development of our bodies and brains as happening when we're kids. But the teenage years are really important to the development of our brains. In fact, it's during these years that we see some of the biggest and most important changes happen in our brains. In this lesson, we'll talk about some of the key changes that happen in our brains as we get older. We can think about the brain as a work in progress; it starts when we're born but needs a while to become a finished product. Let's talk about some of the major changes that happen during adolescence.

Changes in Structure and Function

As mentioned earlier, we're not born with a complete, fully functioning brain. It takes some time for this organ to fully develop. The brain consists of millions and millions of neurons, or the special cells of our central nervous system that transmit signals to the brain and beyond. During adolescence, one of the most important changes going on is the forming and reforming of connections in our brain.

This is part of what we call synaptic pruning, which is a process where we eliminate excess synapses, or the gaps between neurons where communication signals happen. Basically, as we're growing up, we develop many, many new neurons and synapses. They develop at an extremely rapid rate and we end up with far too many of them! This is where pruning comes in. We get rid of the connections that we are no longer using to make the whole system more efficient. Think of this as 'use it or lose it'. Basically, if we don't exercise certain connections we'll lose them in the pruning process. So, it's not completely random how we get rid of some connections but maintain others. Think of it like your rose bushes outside. You prune excess or dying parts to make what's there better.

This process also helps to explain why it's generally easier to learn a foreign language or a musical instrument when we're younger. We should learn to do these things before our brain starts pruning away connections. When we lose some of these connections, we also lose some of our brain's plasticity, or the brain's ability to change throughout our lives.

As synaptic pruning is occurring, we also see the development of myelin, or the substance that is wrapped around nerve cells. It allows those cells to communicate with one another better and faster. Myelin is a fatty matter that is essential to the proper function of nerve cells.

As we get older we develop more myelin around our neurons
neuron; teenage brain

Adolescence and the Frontal Lobe

The frontal lobe is the part of our brain that is responsible for high-level functioning. So, it drives things like decision making, thinking, and processing emotions. It's also kind of the house for our personality. The frontal lobe is critically important and we use it every single day.

The frontal lobe is key to high-level functioning
teenage brain development

During the teenage years, we're beginning to develop some of our higher-level functioning. We begin to use our frontal lobe more and more. Basically, the frontal lobe is not fully developed in teens and this has some implications for how teens behave, think, and interact. This has a lot to do with our previous discussion on myelin. The neurons that connect the frontal lobe to the rest of our brain are kind of slow when we're teenagers because we haven't developed a lot of myelin yet - these neurons can't communicate very quickly yet.

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