Go Ask Mom

Go Ask Mom

What's going on in there? Researcher explains teenage mind

Posted September 14, 2015

Ever wonder what's really going on inside the brains of teens - the ones constantly clicking away on their phones or testing their parents' limits or responding to everything with eye rolls?

Jamie Hanson, a postdoctoral fellow at Duke University and the University of North Carolina at Chapel Hill, has some answers. Hanson received his PhD from the University of Wisconsin-Madison, in a degree program that integrated developmental psychology, the neuroscience of emotion, public policy and biostatistics. His work focuses on children and adolescents.

Hanson will lead a discussion this week about the teenager's mind during the N.C. Museum of Natural Sciences' weekly Science Cafe. It's 7 p.m. to 8:30 p.m., Thursday, at the Daily Planet Cafe inside the museum's Nature Research Center. The event is free and open to the public. Food will be available inside the cafe.

I checked in with Hanson by email to learn more about what researchers are learning about the teenage brain and what this all means for us parents. Here's our conversation:

Go Ask Mom: For generations, we've known that teens tend to be risk takers, overly emotional and impulsive. Thanks to new research, we're starting to better understand why. What are researchers doing now to explore the teenage brain?

Jamie Hanson: The increasing availability of MRI (Magnetic Resonance Imaging) and other neuroscience tools have made it much easier to study the teen brain. About 25 years ago, the first large studies of child and adolescent brain development were occurring. Now, there are hundreds that have been completed or that are on-going.

Researchers started with a focus on brain structure (literally, how big or small different parts of the brain) were. More recently, fMRI (functional MRI) has allowed scientists to use experiments in children and teenagers to measure the processing of emotions, receiving rewards and making decisions. Some research groups are even (cleverly) manipulating social context in the MRI scanner, having participants play games against others or seeing how having a friend present at the lab impacts your brain activity.

All of this research has started to pay off, telling us some surprising new things. For example, did you know that some structures in the brain are changing up until the mid-20s! For the longest time, we thought the brain did most of its development in utero and in infancy.

GAM: Why do some adolescents make bad decisions? Do we know why others seem to glide through this period without a problem?

JH: We are still researching this and trying to figure it out. It is, however, clear that many “bad” decisions come from differences in brain circuits related to emotion, the processing of rewards, and so-called “executive functioning” (these are management or control behaviors, like planning, problem solving, switching between tasks). Many researchers are especially interested in the imbalance between these processes. For example, adolescents may have high brain responses to reward, while the brain circuitry involved with these “executive functioning” are still developing. A colleague specifically says the teenage brain is like “a car without brakes." Teens can accelerate (and take risks), but the ability to stop (and resist impulses) is still maturing.

GAM: Is there something in the brain that can tell us about why behavior changes so much from childhood to adolescence?

JH: One thing is the development in brain structure. The two major tissues in the brain go through big changes from childhood and adolescence.

The gray matter (it literally is grayer on an MRI) increases in volume until about puberty and then decreases in volume. Gray matter is “what fires in the brain." Researchers believe volume goes up to help behavioral flexibility (you can do lots of different activities), but goes down later to promote behavioral specialization (getting better at a few specific things).

The other tissue in the brain (white matter) is “the wires” of the brain. This tissue helps distant parts of the brain talk to one another quickly. It is kind of like insulation. White matter helps information in the brain, conveyed through electrical activity, from leaking out and being slower. The combination of those two major developmental patterns is one simple way that we have connected the massive changes in behavior during development, to something in the brain.

GAM: Are there some things we still don't understand about the teenage brain?

JH: There is so much we don’t know about the brain! One big thing is the interaction between many different brain regions, especially over time. We often focus on one or two brain regions and study activity at one time point. For example, if you have higher levels of brain regions responsible for processing emotion but also higher levels of brain activity in areas responsible for these control “executive functioning” tasks, are you more or less likely to have problems with decision-making, than someone who has low activity on both? How do these things change over time?

Also, the brain is highly plastic (or changeable). We are still understanding how genetic factors influence how the brain develops, as well as the role of experience. For example, do positive (or negative) experiences at certain times during childhood and adolescence have larger effects on the brain? We are just starting to study such questions.

GAM: What does this all mean for us parents? How can it help us as we try and sort out how to discipline and interact with our teens?

JH: Many researchers think that the major changes in the brain (and also the major increase in risk-taking) are normative. They help kids figure out things (even if it is what not to do). Parents can hopefully realize that a little bit of risk-taking is OK (maybe even healthy) for teens. The helpful thing is to support kids so they can take some risks, but not go overboard (and get in trouble).

Another thing is the power of peers. Research suggests that social interactions become really important in adolescence (hence the often non-stop texting with some adolescents). Some brain imaging work has found the brains of teens activate more strongly when interacting with their peers (compared to adults doing something similar). Again, parental support is crucial, giving teens’ time with peers feels rewarding (but staying in control and making smart choice when with peers is also critical).

Hanson will share more at Thursday's event. The Raleigh museum's website has more information.

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  • Djofraleigh Anderson Sep 16, 2015
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    Did we learn anything new & useful from this? Gray matter increases and decreases. People are different. Young people are impulsive risk takers. None of that is new. Nothing about sex differences, but full of age differences. Why don't some of us grow up before 40?