The Adolescent Brain: A Work in Progress

Presenter: Pat Wolfe, Mind Matters, Inc., Napa, CA

This session is presented in separate parts. Use the buttons at the end of the transcription to navigate between each part.

Part Three

PAT WOLFE: Now, we are looking at brain growth and development in the adolescent. The emotional centers are growing very fast, very strong, and are taking over quite often for the frontal lobe. These kids are not good at reading emotions. Does this mean that perhaps they misinterpret what adults are saying sometimes? And we say, Didn't you hear me? Couldn't you tell I was angry? And maybe they indeed could not. That part of the brain was not working well.

Now, Yurgelun-Todd did another experiment. She took adolescents and adults and she put them in a PET scanner. Now, you know what a PET scanner does. Your brain operates on glucose. They put radioactive glucose into your bloodstream and put you in a scanner, and the part of the brain that is working the hardest will give off the most radiated glucose. That shows up on a computer screen in color. And so the areas that show up in bright white are an area of the brain that is working very, very hard. And then red and then yellow and greens and blues and purples.

Now, let me back up. If you are working out of your amygdala instead of your cortex, what are your actions going to look like if the amygdala is taking precedence?

Bob Sylvester uses this term, and I really like this, reactive versus reflective. Your amygdala is set up so you react very quickly in dangerous situations. The cortex is designed for thoughtful reflections: What should I do in this situation?

Because, interestingly enough, when you go into fight or flight and the amygdala has set off this whole fight or flight response, what happens in the body during fight or flight? Are there any changes in the body during fight or flight?

I do not know if any of you saw Newsweek last week. Or this was in Discover magazine. They started a three-part series on fear and emotion. It is excellent. And this was one of the diagrams. And it is showing all the different things in the body that are affected by the fight or flight response, when you perceive a situation to be threatening. Now, this system was set up to save us from saber-tooth tigers. Unfortunately, our brains today do not distinguish between physical threat and psychological threat.

So, whenever you are in this situation and there is all these things happening, your blood pressure goes up. Your lungs are producing more oxygen. The liver is producing more glucose. Digestion is shut down. The immune system is shut down. Hair follicles shut down. Just all these things happen. What do you suppose happens to the frontal lobes, to the cortex, the rational thinking part of the brain? It shuts down.

Have any of you ever been insulted and could not think of a response until the next day? That is an example.

So Yurgelun-Todd decides to see, is there anything different in an adolescent brain and an adult brain when they are in an emotional situation. And in this case she used pictures like that of different -- actually, some of them are just awful, people with terrible skin diseases or horrible accidents. And look what she finds.

Here is the amygdala down here and here is the frontal lobe up here. Which brain is the adolescent? Left or right?

AUDIENCE RESPONSE: Left.

PAT WOLFE: Left, yes.

What you find is almost no activity in the frontal lobe in the adolescent. They are reacting almost -- this is physiological. And you already knew this, that they are emotional and they act emotionally. But you see, what you have the ability to do is to say -- you just heard a comment that was negative and you thought it was about you and you go just like this, you go into fight or flight. And then you realize that the person was talking about someone else or you realize that the person who said that is your boss, and you send a message back to your amygdala and you say, cool it. This is how I feel, but I had better control my emotional response, because it is not socially acceptable to shoot that person even though that is what I feel like.

But that does not happen in the adolescent brain. That does not happen. The frontal lobes just are not activated. The amygdala takes over. Joseph LeDoux talks about the amygdala hijacking the brain, and the part of the brain that is being hijacked is what...?

AUDIENCE RESPONSE: The frontal lobes.

PAT WOLFE: The frontal lobes, that reflective part of the brain.

Time to do a little bit of processing here. Before we start talking about applications of this, would you turn to the person next to you and see if you can recall what the three changes are. What are the three major changes that are taking place in the adolescent brain? And remember, you do not have a finished brain until 18 or 20. See if you can explain those to the person next to you.

[Pause]

PAT WOLFE: Some more bad news here. Let's talk about alcohol and drugs for just a minute. There are a lot of misconceptions about alcohol and the brain. You have probably heard that every drink of alcohol kills X number of brain cells. I have always been curious to know how they know that. Think about that. How would you know that? Now, I live in Napa. I do like a glass of wine. And that is probably not true.

I am not saying alcohol has no effects on the brain. You all know that alcohol does have effects on the brain. It slows down your reaction time. You get a couple of drinks and there is something called disinhibition. That is where you get up on the table and dance with the lamp shade on your head. It can cause sedation. But as far as permanent damage, we do not have a lot of evidence that, in the adult brain, that alcohol does a lot of permanent damage. Even if you are an alcoholic, you will have some mental problems, but you will die of cirrhosis of the liver rather than brain damage.

I think we made that up to try and keep kids from drinking. Well, you are killing brain cells. They do not give a hoot. So, I do not think it works. I have to tell a story, because this ties in here. This is a real bird walk. Pardon me, Madelyn Hunter, but it is.

This teacher decided to teach her kids the evils of alcohol. This is a fifth grade class. She brings in two glasses one day and she sets them up on her desk. And she said, okay, kids, now this glass has water in it. This is Jack Daniels whiskey. I am sure she got permission to bring it into the classroom.

And then she takes out a little baggy and takes out an earthworm and she puts it in the glass of water and it swims all around. And then she takes it out and she puts it in the alcohol and it shrivels up and dies. And then she says, okay, what does that prove? A kid in the back of the room raises his hand and says, if you drink alcohol you will never have worms.

[Laughter]

PAT WOLFE: So, watch what you tell kids.

The question that the scientists are asking now is, as we are doing the shaping and fine tuning of the frontal lobes, is this a time when alcohol might cause more damage than in the adult brain? And guess what the answer is. The answer is yes. Drinking may be more dangerous for adolescents than for adults because the finish touches on brain development haven't been done.

There are several studies here. One found that hippocampal capacity or the actual size of the hippocampus had shrunk. Now, what does the hippocampus do? It is responsible for memory. And the more the kid drank, the smaller the hippocampus became. And it is through growing, basically.

Another study found that alcohol-dependent adolescents perform much more poorly on tests -- cognitive kinds of things -- and actually to the point of decreasing LTP. And incidentally, these are not the same results they are getting in adult brains. It appears that the adolescent is much more vulnerable to the effects of alcohol than the adult brain.

Jay Giedd, who is at the National Institute of Mental Health, from whom I got a lot of this information, says adolescents do not realize that they are impacting their brains not just for one night or for a weekend but maybe for the next 70 or 80 years.

This is a picture, an actual PET scan, of a 15-year-old male who is a heavy drinker and a 15-year-old male who is not a heavy drinker. These are both males. Oh, you cannot see it at all. This one has all kinds of red. This one has three little spots of red. This is during withdrawal.

This 15-year-old kid who is a heavy drinker has had no alcohol for two weeks. And it appears that it is during withdrawal that you see the most damaging effects. There is about three times more activity in the brain of the non-drinker than in the heavy drinker. And alcohol is much more socially acceptable in our culture than drugs are, and it appears to be doing more damage to the adolescent brain.

Nicotine. The vast majority of smokers have started smoking in their adolescent years. Now, I have to tell you that this research has been done in rats, not in humans, because you cannot do it in humans. Nicotine is one of the few drugs that does a really funny thing in the brain. It increases memory, incidentally. It is not a reason to smoke, but it does. They are actually using nicotine patches on some Alzheimer's patients to see if they can improve memory.

But what happens is the more nicotine you put into the brain, the brain develops more receptor sites for it. And if you have more receptor sites, what are you going to need? More nicotine. And the receptor sites dedicated to nicotine, the sign of addiction, increased twice as fast in the adolescent rat brains as they do in the adult rat brains. In other words, here again we are developing this brain and it is very vulnerable, and the impact of drugs and alcohol appears to be much greater between, say, ages 11 and 20 than they will be after or that they were before. We have a very vulnerable brain here.

Ecstasy. It appears to be the major recreational drug. Now, what does serotonin do? Remember serotonin? This is one of the neurotransmitters. You have two major mood-enhancing neurotransmitters in the brain. One is called serotonin. One is called dopamine. Serotonin is a kind of calmer. It is a feel-good. Why does the brain produce something to make you feel good? You have a reward system in your brain. Why do you have a reward system in your brain?

It is to reward you for doing things that keep you alive, keeps the species alive. Survival. So, is eating pleasurable? Yes. It had better be or the species would die out. Is sex pleasurable? Someone said it is supposed to be, but anyway.

So, you have this reward system. And one of the chemicals, one of the neurotransmitters in the brain, and there are several -- dopamine is also included -- but it is serotonin that makes you feel good when you do these things. It increases. It is a natural tendency of the brain. Prozac keeps serotonin in the synapse longer and causes you to feel better, perhaps to handle whatever is causing the depression. So, that is why they are antidepressants.

Well, what they have found is that Ecstasy is destroying serotonin receptors in the brain. And here again, there is a much, much greater magnitude of effect of Ecstasy on the adolescent brain than on the adult brain. So, it can actually interfere not only with mood but there is some evidence that it interferes with mental function as well.

This is the last piece. Sleep in the adolescent brain. I have been telling everybody in my workshops, do you want to do something really good for your brain? What is one of the best things you can do for your brain? Seven and a half to eight hours of sleep every night. Why? Every 90 minutes you go into deep REM sleep, rapid eye movement sleep. That is when you are doing all that crazy dreaming. It happens about every 90 minutes. Whether you remember it or not, your brain is dreaming.

And dreaming in the human brain is a fascinating topic and everyone is always trying to figure it out. But one of the things we know is that, when you are in deep REM sleep, your body is essentially paralyzed except for essential functions and except for the eyeballs. They really move around a lot.

So, this is a really good time for the brain to do some things that it could not do during the day while you are up running trying to solve quadratic equations. It is a good time to do some other things. And one of the things it does is it rebuilds it cells. So, this is when all the nutrients are being brought in by those glial cells and you are repairing the cell walls.

Another one, which is still a bit controversial but there is some evidence that sleep is a time when your brain continues to fire connections it made during the day. In other words, 98 percent of brain processing is unconscious. Your brain is doing all kinds of things right now that you are not aware of. And so you say to people, what do you think brain waves look like when you are asleep? And they say they look pretty flat. No, they are spiking all over the place -- and this is during dreaming.

Well, it may be that what your brain is doing is rehearsing. It is rehearsing what you learned during the day. So that sleep can also impact your memory. Well, we live in a culture that brags about getting by on less sleep. But some of the most interesting research has come from a woman named Mary Carskadon, who is looking at the sleep patterns in adolescents and finding two things.

Number one, they need much more sleep than we thought they did. So, we know that young children, your elementary school children, need 10 to 12 hours and that the adult needs seven and a half to eight. And we thought we had an adult brain here, so we thought adolescents needed seven and a half to eight. And what she has found out, through sleep lab experiments, by letting kids sleep an optimal time and just finding out when they wake up, it is about nine and a half hours.

Now, that is bad enough. How many of you know an adolescent who gets nine and a half hours of sleep at night? That is only half of it. Do you know what Circadian rhythms are? That determines your sleep and wake cycles. In most of you, your sleep-wake cycle is set for like 10 o'clock at night and 6 o'clock in the morning, approximately. What they have discovered is that in the adolescent brain it is set much later.

They don't get sleep -- and this has to do with melatonin levels. You have a little gland in your brain called the pineal gland. It produces melatonin and, according to the cycle in your body, around 9:30-10 o'clock, melatonin begins to increase. It has gotten dark outside and you have been up X numbers of hours, and the brain says, okay, let's send out some melatonin. Let's make this person sleepy. And then, after you have slept your seven and a half to eight hours, it begins to get light, melatonin decreases and you wake up. It is much more complex than that, but you can deal with that.

So, in the adolescent brain, it does not happen at 10 o'clock. It does not happen until 11:00 or 12:00. For some unknown reason, the body clock, the sleep clock in the adolescent, is set later than either elementary or adults. So, what are the implications of that? Start time.

And I taught the high-schoolers. And I thought I really liked it because they stayed in their seats. Of course, they were also sleeping. So, for the most part, you stay in your seat when you are asleep.

Districts are beginning to look at this. And of course one of the biggest problems is it is expensive because you have to change bus schedules and athletics, et cetera, et cetera. But the point is that when you have these early classes and you have kids sitting there asleep, they are not going to go to bed earlier and sleep earlier because they are not sleepy yet. So, this is another big change that is taking place in the body.

Now, I thought long and hard. This information is important to know. But as I was thinking about it, I thought, sure, you have got this audience here, but it does not help much does it. Well, maybe it helps to know why they are the way they are. Well, what do you do about it, those of you who teach middle school and those of you have adolescents?

And I did a lot thinking and a lot of reading on it and it came up -- and this is not anything esoteric -- but there are a few things. What do we do with the existing research? Well, number one, please be careful with it. Don't take giant leaps from this into practice. It is not that set in concrete. Sure, these changes are happening, but we do not know exactly what we were are going to do with it, so be careful with it.

But, too, I think we need to be sharing this information with the adolescents, and many researchers feel the same. Do any of you remember when you were an adolescent? Do you remember the confusion? Do you remember that you did not like your body? Do remember you would think, I was too tall and nobody would ask me for a date. And I felt gangly, and everyday was a bad hair day.

And I remember -- I kept one of those five-year diaries. You write a little bit each year. And I do not know why this stuck in my mind, but I was probably about 13 and I wrote: I wish someone would tell me who I really am. Because one day, I think I am this and the next day I -- one day, I think I am really nice and the next day I think, I am really an awful person.

These kids are going through misery in many respects. But if we could explain to them what is going on in their brains and let them know that it is normal and let them understand the changes that are taking place, but, more importantly, letting them know that they have some control over this.

Jay Giedd says -- and he has scanned over 400 children from age three through age 17, 18, his own son included -- and he is the one who has been able to show with functional MRI's and PET scans all these changes that are taking place in the brain. And he says, I think it is a very empowering time. The kids need to realize that you sculpt your brain through experience, and what you are doing with your brain now is going to determine what your brain is going to become.

What kind of connections do you want to make? What kind of a brain do you want to build? Are you going to build a brain that is more comfortable sitting in front of videogames and watching TV or do you want a brain that is engaged in music and sports, et cetera? I know this is no easy solution, but it might help some of our adolescents to know.

See, one of the things they really like is control. Well, probably the most important thing they have control over is their own brain. But I do not think most kids understand that what they are doing with their brain now is going to impact their brain the rest of their lives. And maybe giving them this information and having them take a look at the research could actually be very empowering and could make some changes.

The other thing is that I think we need to take advantage of some of the characteristics. They are argumentative. They are cantankerous. But maybe this would be a really good time to engage them in debates in classrooms. They are very concrete -- and I am not sure I agree with this -- but many of the researchers say they are not ready for higher-level abstract thinking. My own feeling on this, and this is my own feelings not researchers, is well, you say those eighth-graders are not ready for algebra yet because it is too abstract. I think maybe we think it is too abstract because we are teaching it abstractly. And I think they could learn it a lot earlier if we were teaching them in a concrete manner.

[Applause]

PAT WOLFE: But somehow we get to this place where we say, okay, lots of concrete experiences for our young children, lots of hands-on, lots of manipulatives in math. Oops, now you have hit Piaget's level of abstract reasoning, so we are not going to give you any concrete experiences. We are going to teach you totally abstractly.

I think first-graders could understand algebra if it is taught in a concrete manner. So, I am not sure that when the researchers say they are not ready for abstract thinking yet, I think it depends on how you structure the learning experience. So, my suggestion would be we need more hands-on experiences, not less, at the middle schools. Science experiments, discovery, emotional involvement, let them use that emotion. Let them debate two sides of an issue.

Use these traits that they have to your advantage. But knowing what you know about the adolescent brain, you know that sitting in a chair and listening to a lecture and taking notes probably is not the best way to teach these kids.

Well, you will probably be really unhappy but I am letting you out five minutes early because I am through. Thank you very much.

[Applause]

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