Saturday, June 23, 2007

Teen brains: the angst of growing up

What doesn’t kill you will make you stronger

Having two teenagers, I have often marveled at how they could be model young adults one moment, then in the next breath suddenly become demons of the underworld- spitting saliva and barking accusations from one end of their mouth to another. These tumultuous years are full of emotional extremes; incredible high and lows that give full merit to its description of real angst. It is not a philosophical or poetic version, but a gut wrenching, heart pounding visceral angst that reaches down into the very essence of who and what you are.

Indeed, that is exactly what happens to all of us during these brief pubescent years. Perhaps learning what is occurring in a teenage brain will help bring more understanding of why our teens might do some of the things they do. For example, where does that yo yo moodiness come from? How about many teens propensity for risk taking? Where does that maddening expression and disdaining look; that “whatever” attitude come from?

In the last decade neuroscience has given us a glimpse into the teenage mind and has revealed an incredible sea storm of dynamic change. In general, during this stage the brain has no where near the rhythm and fluidity the adult brain might have. It seems to run more like the uneven staccato of an untuned Harley motorcycle rather than the smooth balanced humming of a BMW roadster.

The teenage cortex is undergoing huge fluxes as actual anatomic changes rewire areas and bring “online” new emerging functions between cognitive centers. Hormonal fluxes take part in triggering outgoing behaviors and a yearning for new experiences and risk taking. This period of human development has been described as the second flowering of the brain, second only to the dramatic changes of early childhood.

There is a flurry of change that relates to higher conceptual thinking. The body begins to produce a maze of new and transforming neurotransmitters that create inummerable connections within the brain. Myelination begins to rapidly produce higher speed connections between differing regions and centers. The sum effect is that the cortex begins to grow into a richer, more nuanced, and complex region. This period in life is reminiscent of the transformation from caterpillar to butterfly- that mysterious and sublime point where everything changes.

At the end of this period, there is a reduction of the exuberant fluxes within the brain. As a teen becomes a young adult, his or her brain begins to lose many connections as it begins to shape a “leaner and keener” disposition. In general, it becomes more efficient, balanced, and wise.

One of the most tumultuous areas “under construction” during the teen cerebral explosion is the prefrontal cortex. That area involved in forethought, judgment, and consideration. That this area develops late helps one understand a teens behavioral extremes. It takes a teen more effort to do what adults can do with ease. In a simple experiment Beatriz Luna, director of the laboratory of Neurocognitive Development at the University of Pittsburgh, instructed teens and adults to avoid looking at lights that appeared on a computer screen and an MRI scanner recorded their brain activity.

She discovered that though, both teens and adults were equally adept at diverting their gaze, teens relied much more on the prefrontal cortex than adults. In other words, the mature adult prefrontal cortex efficiently delegated this function to other brain regions. Teen brains used up the all important prefrontal cortex just for this simple task; predisposing them to become overwhelmed. Luna remarks: “So if they’re under emotional stress from peer pressure or in a situation that requires them to multi task, their performance is likely to deteriorate.”

Teens also have difficulty in reading different kinds of emotions from others. For example, they might have trouble distinguishing anger and shock. This relates to the fact they are far more sensitive to the influence of the limbic system- the fight or flight region and source of emotional feeling. The adult prefrontal cortex, on the other hand, generally has a tempering effect on these surging feelings.

If that weren't enough, other factors influence the tumultuous impulses within the teen brain. Dopamine surges bring about powerful urges to experiment and take exceptional risks. This is a period of searching out and moving on; flexing ones wings so to speak. There are profound evolutionary pressures at work that likely relate to expanding outward from immediate family bonds, to find new partners, developing independence, and exploring new opportunities.

There is also an added window of susceptibility for teens towards many negative dangers presented to them. There may be an increased predisposition to addiction, and adverse risk taking that pushes the boundaries too far. This is part of a parents own unique form of angst! On the positive side Scott Swartzelder, a neuoropsychologist at Duke University states that: “A brain in flux is more open to new experiences and to exploring the world- all of which enhance survival.”

Overall, this insight brings some sense and reason to why teens can be as maddeningly and abrasively frustrating one moment yet wonderfully gentle and cooperative another. Some of us adults may forget we once had pretty major mental surges, epiphanies, and far reaching urges- that we were once teens as well.

Surviving these years provides the foundation for our brains to develop towards broader awareness. It allows for the “I am me” in us to fully flower and reach the most profound contextual depths of “humanness.”

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