The Adolescent Brain: A Work in Progress
By Lisa K. Schkloven.
If you’re living with an adolescent it’s a good idea to understand what’s going on. Adolescence is a time of rapid physical, cognitive, emotional, social and moral development and change.
As the parent of a teenager, how many times have you either thought or said the following: “What were you thinking ?!” Until recently, conventional wisdom held that early childhood was the time when a person’s brain grew the most. It was “thought” that by the time a child reached the age of twelve, the brain for the most part had finished its development.
Then in 1991, Dr. Jay Geidd, a neuroscientist and chief of brain imaging in the child psychiatry branch at the National Institute of Mental Health (NIMH), began using magnetic resonance imaging (MRI) to study the brains of some 1,800 children and adolescents over a period of thirteen years. Geidd discovered that, not only is the adolescent brain far from mature, but adolescence is a time when extensive structural changes occur in both the gray and white matter of the brain. The reality is that the teenage brain is undergoing continuous restructuring throughout the adolescent years and into early adulthood. To better understand what your teen is and is not thinking, here is a “Reader’s Digest” version of your teenager’s brain.
The brain develops in stages, from the back of the brain to the front, through a process of neural proliferation and pruning. The first part of the brain to mature is the back part. This area of the brain controls the senses such as touch, sight and hearing. The next parts of the brain to develop are the areas that help organize and allow the senses to make order out of its environment. Over the ensuing years, the brain continues to develop, back to front. The last part of the brain to develop is the front, specifically the prefrontal cortex of the brain. That is the part of the brain that governs what is called “executive functioning”.
Located right behind the forehead, the prefrontal cortex is the CEO of the brain. The prefrontal cortex is responsible for a person’s ability to organize thoughts, think things through, set priorities, weigh one’s options, consider the consequences of one’s actions, delay gratification, suppress impulses and make sound decisions. This thinking, rational part of the brain is truly a work in progress that will not be completed until a person is in his or her mid 20s.
Because the CEO area of the brain is not fully functioning, another part of the brain steps in to take its place. Called the amygdala, this almond shaped part of the brain is situated deep in the back of the brain. Whereas adults use the prefrontal cortex in making their decisions, adolescents rely on the amygdala, the emotional and instinctual center of the brain, in making their decisions. That’s why even with teens who seem to have relatively good judgmental skills, the quality of the decision making ability declines dramatically in moments of high emotional arousal. Emotions such as happiness, anger and jealousy override logic. Even more, the intensity of emotional arousal and response increases when teens are with their peers.
To complicate things further, one has to add to the mix the hormonal influences and fluctuations that occur during adolescence. In her 2004 article for Time magazine, reporter Claudia Wallis sums up this phenomenon this way, “For years, psychologists attributed the intense, combustible emotions and unpredictable behavior of teens to this biochemical onslaught. And new research adds fresh support. At puberty, the ovaries and testes begin to pour estrogen and testosterone into the bloodstream, spurring the development of the reproductive system, causing hair to sprout in the armpits and groin, wreaking havoc with the skin, and shaping the body to its adult contours. At the same time, testosterone-like hormones released by the adrenal glands, located near the kidneys, begin to circulate. Recent discoveries show that these adrenal sex hormones are extremely active in the brain, attaching to receptors everywhere and exerting a direct influence on serotonin and other neuro-chemicals that regulate mood and excitability. The sex hormones are especially active in the brain’s emotional center…”
According to Dr. Ronald Dahl, professor of psychiatry and pediatrics at the University of Pittsburgh School of Medicine, this hormonal mixture in the brain creates a “tinderbox of emotions”. This helps to explain why teenagers display a high rate of emotional reactivity as well as why they seek a high level of emotional stimulation. According to Dahl, “Adolescents are actively looking for experiences to create intense feelings,” says Dahl. “It’s a very important hint that there is some particular hormone-brain relationship contributing to the appetite for thrills, strong sensations and excitement.”
Therein lies the crux of the age old adolescent behavior and the crux of the age old parental dilemma. Teenagers, because of brain development and hormonal surges and fluctuations, have had the thrill seeking parts of the brain activated well before the rational part of the brain is up to the challenge of controlling it. It’s not that teenagers are stupid; it’s just that teenagers do not think like adults.
So why do teenagers appear unmotivated to do one thing yet highly motivated to do another?
According to Dr. James Bjork, author of NIH’s National Institute of Alcohol Abuse and Alcoholism study published in the February 25, 2004 issue of the Journal of Neuroscience, “Adolescents show less activity than adults in brain regions that motivate behavior to obtain rewards.” Dr. Bjork concludes, “If adolescents have a motivational deficit, it may mean that they are prone to engaging in behaviors that have either a really high excitement factor or a really low effort factor, or a combination of both.” Bjork advises parents, “When presenting suggestions, anything parents can do to emphasize more immediate payoffs will be more effective.”
Cuba kaitkan rencana di atas dengan rencana saya sebelum ini mengenai kesan bahan lucah kepada kanak-kanak.
Apa pendapat anda?