The Teenage Brain by Priya

Aside from the, erm, ‘visible changes’ during adolescence, there are much prefrontal-cortexmore changes going on in the teenage brain. The truth is, after primary school, the brain goes through massive neural changes too. When I say neural changes I don’t mean our brain gets larger, because our brains are about 95% full-sized by the time we are just six, I mean prepare for the world.  Anyway, my first question is:

Why do teens like to sleep in till 11am?

So, we all have hormones at whatever age and they don’t just promote crazy emotions during teen years, they do a range of things like keeping your heart beating, your body hydrated, they make your bones, muscle and skin grow etc. And the reason teens often find it hard to get out of bed and often like to stay awake late at night watching the Simpsons or the latest Walking Dead episode is because all people have a hormone called melatonin, which makes us feel sleepy and winds us down.  And so scientists have discovered that for adults melatonin kicks in around 10pm, but for teens, it kicks in around 1pm.  This is because the hormones that are making the changes in their bodies keep them energised during the night. This then makes them want to lie in all Sunday morning. But this could also be because they have been up all night playing video games.

Why do teens sometimes think irrationally or recklessly (in general) and why should they start learning more?

Once we are adults we have a prefrontal cortex, which is in the front of the brain, this is the part of the brain that is responsible for enforcing judgments rationally by communicating to the other neurones in the rest of the brain. There are also neurones called synapses. But when you are a teenager, the prefrontal cortex isn’t quite fully developed like this yet. In fact, it is only fully finished when you are in your mid-twenties. Teen’s synapses aren’t fully grown yet it also means that they are actually quite…. slow.  So if a teenager watched a marathon of Britain’s Got Talent the night before an exam, it doesn’t mean they are dumb or stupid (depending on the teen), it means, as the prefrontal cortex is the last part of the brain being built it, their brain is literally finishing being built.

At the same time though, because all this brain building is about to finish, it also means that it is being thinned out. It starts losing connections that aren’t used enough. It is a process called synaptic pruning which has led to a theory that it is a ‘use it or lose it’ period for the brain. Which means that adolescence is the most important time to use your brain! Play sports, learn languages, play an instrument, write poetry! Doing these things, you are helping hardwire those synapses in lasting shape. But if you’re sitting around all day playing candy crush and flappy bird, well, that is what will be the connections that survive. Which, face it, you really don’t need.

But the main reason teenagers sometimes behave recklessly is because whereas adults use their prefrontal cortex to handle decisions, teens use a part further back in their brains called the amygdala. The amygdala is the main gut reaction and emotional part of the brain, which reacts quicker, not so thought out.

What’s with the frequent mood swings?

As I explained before, teenagers use the amygdala in their brains, which reacts quickly and emotionally, it also suggests why teenagers have the mood swings. The frontal cortex is also used to read and understand circumstances and expressions but as this is fully developed, again teens have to use their amygdala, which can misread expressions.

Scientists did an experiment using MRI devices where a group of adults were shown some pictures of expressions and most labelled them right as fear, but when a group of teenagers did it they labelled it as excited, shocked or angry. Showing clearly, that teens don’t run their decisions by the rational frontal cortex first. This leads to not only misunderstandings, others emotions or expressions, but their own feelings which commonly makes them want to risk take more often too.

And so, although our slow, risk-taking, mood-swinging, reckless adolescence might be hard, it makes our brains more flexible and adaptable to the future grown up world.