From the Principal’s Desk – 28 February, 2019
At times, teachers and parents get perturbed when our adolescent children can be mature one moment and frustratingly immature the next. Over the past few years, medical research has cast light on how the nature of brain development can help explain this phenomenon.
With the development of functional magnetic resonance imaging (FMRI), scientists can see inside the adolescent’s brain and watch what happens when they think. What the researchers have found is that, other than the first three years of life, no period of development is characterised by more dramatic changes than adolescence.
During adolescence, the brain is remodelled through synaptic pruning (the elimination of unused and unnecessary synapses or pathways) and myelination (the covering of neuron projections in myelin tissue increasing the speed of neural impulses and information transmission), particularly in the prefrontal cortex. This is the region of the brain most important for sophisticated thinking abilities such as planning, thinking ahead and weighing risks and rewards. The myelination of this area also leads to improvements in teens’ ability to regulate their emotions and co-ordinate their thoughts and feelings. However, maturation of the prefrontal cortex is not complete until the mid-20s.
At the same time that the adolescent brain is maturing to enable teenagers to become more capable of reasoned thinking, it’s also changing to make them do risky things. During adolescence there is a rapid increase in dopamine (the chemical responsible for the feeling of pleasure) in the brain’s reward system. Because things feel especially pleasurable during adolescence, teens go out of their way to seek rewarding and pleasurable experiences, and sometimes not pay any attention to the associated risks.
Laurence Steinberg states:
This combination of advanced (but not yet totally mature) reasoning and heightened sensation-seeking explains why otherwise intelligent adolescents do surprisingly foolish things. More important, the fact that teenagers’ ability to control their impulses is immature at the same time that their interest in sensation seeking is stronger than ever makes them vulnerable to making mistakes.
Understanding the nature of brain development in adolescence helps explain why teenagers can vacillate so often between mature and immature behaviour.
When it comes to more basic abilities, such as those involving memory, attention, and logical reasoning, the average 15-year-old is just as mature as the average adult. But … relatively sophisticated cognitive abilities such as thinking ahead, envisioning the consequences of a decision, balancing risks and rewards, or controlling impulses, are still developing at that age.
Finally, Steinberg writes that it is important to remember that the brain is very malleable and that its development is affected by experience as well as biology.
Both synaptic pruning and myelination are influenced by experience, such that the repeated activation of a specific collection of neurons as a result of engaging in a particular behaviour will actually strengthen the connections among those neurons, which, in turn, will make them function more efficiently. This is the one reason that practicing the same task over and over again makes that task easier to perform each time.
The writer thus encourages teachers and parents to provide our teenagers with opportunities to practice things like planning, anticipating the consequences of a decision, and regulating their own behaviour.
Over time, with practice, as synapses are pruned and neural circuits myelinated, adolescents’ ability to exercise mature control over their own behaviour will improve.
Wishing you all a relaxing weekend ahead.