ATTAINING MATURITY / WINDOWS OF VULNERABILITY [ WAVES OF CHANGES – AN ADOLESCENT BRAIN ]
The frontal lobes, last to receive their myelin coating, playa crucial role in choosing proper behavior, inhibiting inappropriate behaviors and selecting the best actions for meeting goals. If not fully myelinated, a teenager’s brain may not be well equipped to make good choices. Teenagers most likely react to events with more of an emotional charge because their limbic system, including amygdala, is more fully formed than their frontal lobes.
The prefrontal cortex, the part of the frontal lobe closest to the forehead, takes a long time to mature. It first expresses function with the ability to pay attention, which develops a few weeks after birth as infants focus on and anticipate events around them. By a year old, a child can move an object out of the way to get to a toy, which demonstrates a choice of action as the means to an end. At the same time, the child begins to use language and symbols to represent the world, a crucial step in the formation of memories. Self-control, an important executive function, develops over the next year or two.
Attention and alertness increase through age six, and major cortical development occurs between ages seven and fifteen. Afterward, pruning sharpens the prefrontal cortex as the youth acquires greater control over behavior. Until the youth’s prefrontal cortex is able to make good decisions, parents and teachers help regulate behavior with their more highly developed frontal lobes.
WINDOWS OF VULNERABILITY
In the meantime, the adolescent brain is vulnerable. The prefrontal cortex’s inhibitions-its ability to avoid choosing risky behaviors aren’t fully developed at the age when many youths are most tempted to engage in such acts. Unprotected sex, drug use, smoking, and drinking all are temptations with well advertised consequences, yet the adolescent who encounters them lacks the adult’s ability to weigh long-term actions and say no. For a variety of reasons, adolescents who give in to peer pressure and decide to take drugs or engage in other risky behaviors are unlikely to be doing so because of weak moral character.
Most never exhibited such risky behavior as children, argumg against a deeply rooted character flaw. Instead, many turn to risky behaviors as a result of mental disorders including attention deficit hyperactivity disorder (ADHD) and depression. Many of their family members likely experienced similar attractions and addictions, suggesting a genetic component to heightened risk of dangerous behaviors. Taken together, these clues point toward addictions whether to physical substances or to the thrills of new sensations as a brain disorder linked to neurotransmitter functions.