2 The adolescent brain
Understanding more about adolescent brain development can help you to understand how to support a young person’s mental health. Neuroscience is the scientific study of the nervous system. According to neuroscientists, adolescence constitutes a period of significant transformation in the brain. Neuroscience has advanced considerably since the late 1980s when new imaging techniques such as those you may have already heard of including CT scans and MRI scans, have allowed detailed images to be made of living brains. These images have allowed scientists to understand more about how brains function and develop.
The brain is the ‘control centre’ of the entire nervous system, which comprises nerve cells that transmit messages within the brain as well as between different areas of the brain and the rest of the body. In different parts of the brain, signals from the body are translated into perceptions, feelings, thoughts and actions.
You may be aware that various areas of the brain perform different functions. For example, the occipital lobe at the back of the brain (see diagram below) is responsible for converting the nerve signals originating in the eye into images that you can perceive as ‘sight’. The two areas of the brain that have received the most attention from neuroscientists studying adolescence are:
- the prefrontal cortex
- the limbic system.
Study Figure 7 to familiarise yourself with the locations and broad functions of the prefrontal cortex and the limbic system before moving on to the next activity.
Activity 4: Brain changes during adolescence
Step 1: Watch the first 4 minutes of the TED Talk [to 4.04], in which Sarah-Jayne Blakemore describes some of the changes occurring in the brain during adolescence. Jot down three (or more) pieces of information that you find interesting.
Sarah-Jayne Blakemore’s TED talk: The mysterious workings of the adolescent brain [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)]
Did you get any of these?
- MRI scans have helped to show that brain development continues well beyond the first few years of life, contrary to what people previously believed
- The brain continues to develop into our 20s and 30s.
- The prefrontal cortex is proportionately bigger in humans than any other species
- The prefrontal cortex is important for planning, inhibiting inappropriate behaviour, understanding other people, and self-awareness.
- Grey matter volume peaks in early adolescence (around 12) and then declines.
- Grey matter reduction is known as ‘pruning’, removing the ‘weaker branches’ and fine-tuning the brain.
The grey matter is where the ‘thinking’ occurs in the prefrontal cortex, and the white matter carries messages between different parts of the brain.
Both adults and adolescents found the task more difficult with the ‘director’ than with the ‘rules only’ condition.
Only adolescents found the task more difficult with the ‘director’ than with the ‘rules only’ condition.
The correct answer is a.
The ability to take someone else’s perspective in order to guide their behaviour is well developed in early adolescence.
The ability to take someone else’s perspective in order to guide their behaviour is still developing in mid to late adolescence.
The correct answer is b.
Step 3: Watch the TED talk from 8.30 to 11.39 to discover the outcomes of the experiment. Then, consider for a moment how many aspects of adolescent behaviour could be a reflection of normal brain development.
The outcomes of the experiment showed that:
- Both adults and adolescents found the task more difficult with the ‘director’ than with the ‘rules only’ condition.
- The ability to take someone else’s perspective in order to guide their behaviour is still developing in mid to late adolescence.
Hold your initial thoughts about the link between adolescent behaviour and their brains as you move to the next step.
Step 4: Watch the TED talk from 11.39 to 14 minutes (to the end) and consider the following questions:
- What does Sarah-Jayne Blakemore say about how adolescents process emotion?
- What benefits could there be in having an ‘adolescent brain’?
Make notes here:
In adolescence the limbic system, which is involved in emotion reward processing, becomes hyper-sensitive to the rewarding feeling of risk-taking. At the same time, the prefrontal cortex, whose role is to control impulsive behaviour, is still under development. This may explain the thrill-seeking behaviour of adolescents. In their drive to become more independent from parents and impress their friends, they can also succumb to peer pressure to take more risks.
Brain research has implications for people who work with children and young people because it shows that the brain is particularly adaptable and adolescence is an excellent time for learning.
Linking adolescent behaviour with brain development can help people accept adolescence and some of the behaviours that are displayed then as a normal process rather than see it as abnormal or deviant. Risk-taking and peer pressure are two characteristics that are strongly associated with adolescence, and you’ll consider these further next.