By Audrey Quinn
Posting in Science
Newly discovered networks in the adolescent brain explain why some teens are more likely to say yes to experimentation with alcohol, cigarettes and illegal drugs.
When I met with teen brain researcher Dr. Abigail Baird I first asked her, "Why is it that teens are such a mystery to most adults?" We've all been teens ourselves, why are they so hard for us to relate to?
"I think just the heterogeneity of of what can happen in adolescence makes people very nervous," she explained, "and it's made it very hard to study because we could bring five thirteen-year-old's into the room and they could be at five completely different points of development."
A team of scientists at the University of Vermont, along with a large group of international researchers, set out to find the brain wiring behind those individual differences.
By studying 1,896 14-year-olds, they pinpointed unique brain networks that deal with impulse management, and found that activity levels in these networks correspond to teens' liklihood to experiment with alcohol, cigarettes and illegal drugs. Their findings came out this weekend in the journal Nature Neuroscience.
Using functional magnetic resonance imaging (fMRI), they found seven networks involved when impulses were successfully inhibited and six networks involved when impulse inhibition failed. A University of Vermont press release explains:
These networks "light up," in a functional MRI scanner during trials when the teenagers were asked to perform a repetitive task that involved pushing a button on a keyboard, but then were able to successfully stop—or inhibit—the act of pushing the button in mid-action. Those teens with better inhibitory control were able to succeed at this task faster.
A network "lighting up" in an fMRI scan suggests increased blood flow in that area, meaning greater activity there. Teens with greater activity in their orbitofrontal cortex (a region in the front of the brain's frontal lobes that's involved in decision making) performed better at inhibiting their impulses.
The researchers found that one particular network in the orbitofrontal cortex specifically correlated with an early adolescent's likelihood of starting to use drugs. The study reports that illegal drug use was also "associated with genetic variation in a norepinephrine transporter gene."
The press release states:
This discovery helps answer a long-standing chicken-or-egg question about whether certain brain patterns come before drug use—or are caused by it.
The take home message? A teen's susceptibility to impulsive behavior may be seen in both her brain activity and her genes. Being able to identify which teens are at greater risk for making dicey choices could allow physicians or counselors to intercede before dicey behavior starts.
It will be interesting to see clinical applications of this knowledge, as I don't foresee mandatory brain screenings for impulse susceptibility becoming de rigueur any time soon.
Apr 29, 2012
There are many things that make a teen's behaviour perplexing. Part of it is the teen brain is changing from a child's brain to an adult brain and it takes years to make the transistion. The drive to do risky things may be built in, how are the youths supposed to learn what they can do if they can't push their limits. There are also cultural aspects that make the teen experience different in other cultures. There are also some "milage markers" for teens, moving into a higher grade, beginning to date, learning to drive and others that happen at different times for each teen. As far as adults dealing with teens, adults do have memories of being teens but that is filtered through an adult mind. The really crappy parts of being a teen get glossed over and forgotten as we mature into adulthood; which sets up the generational conflicts.
"...found seven networks involved when impulses were successfully inhibited and six networks involved when impulse inhibition failed..." The math is beyond these researcher's wildest hopes at comprehension. Imagine the three body orbital problem with something as comprehensible as mere gravity. Now imagine 2 juvenile impulses with all individually inherent fluctuations therein, times at least three magnitudes of complication given the nebulous variables considered... I can't imagine there's enough math in the universe (nyuk-nyuk!) to begin to consider conclusions such as posed by these authors. On the other hand children, as we all are in these cosmos, are easy to understand. Other's inconvenience is our convenience. Farts, emulation of Harpies and such often prove the thesis.
Nature makes babies cute so that we'll care for and love on them. Nature makes teenagers obnoxious and repugnant so we'll kick them out of the nest when it's time for them to go.