Monday, February 27, 2006, The Female Brain

Louann Brizendene, M.D.

MS. BRIZENDINE: Good morning, everybody. We have a wonderful day ahead of us. It's my honor to open these sessions, and now more poignantly after last night's wonderful, generous parting gift, with a poem, as I have always done.

The poem that I offer this morning is from another wonderful collection that I share with you called "Word of Mouth," poems featured on NPR's "All Things Considered." The one I selected is from Phillip Booth. You may know him. He's a Maine poet, and he says about himself that he's a student of Robert Frost. He believes that poetry teaches us to survive both spiritually and sometimes literally. And so the poem, in the sense of an offering of metaphorical instruction, is called "First Lesson." Phillip Booth.

So good morning, everybody. And we have Liza.

MS. LEE: I hate following Bodie, and actually, I'm a salesman, just to break the mood. I know that you all enjoyed Jill Muti's playing last night, and it occurred to me that many of you don't know that she and her husband run two wonderful programs in Italy, one for faculty and one for students. As a head, I'm always looking for summer opportunities for my students, so they don't leave me for the year and I retain their tuition. This program is great. Jill, where are you? I asked Jill to bring some brochures. She's right back there. And she's got brochures for both programs, and I am speaking from personal experience. They are really wonderful. And the chance for your faculty and your students to be with the Mutis is terrific. So do find her, if you're interested. And that's my sales pitch just for today.

MS. BRIZENDINE: It's my honor to introduce Louann, who is not my sister, not my cousin, not my daughter, although she looks like she could be. But, in fact, our names are the same. But she is my friend and my neighbor and we've shared a time together in San Francisco when we've actually called one another to say, "Do people ask if you're related? Do people ask if you're related?"

And repeatedly we've enjoyed at least phone conversations. But my favorite phone conversation was moments after I checked into the hotel, and the phone rang, and I picked it up, and someone said, "Louann?"

And I said, "No."

And Bruce said, "Bodie?"

And I said, "Yes."

Bruce was already calling me. Similar name notwithstanding, we're honored to have her here with us today. I'm going to read a little bit of a bio for her.

Louann Brizendine is clinical professor of psychiatry at UC San Francisco and is founder and director of the Women's Mood and Hormone Clinic in San Francisco. While doing research as a medical student at Yale and then as a resident and faculty member at Harvard, Louann discovered that almost all of the clinical data in existence in neurology, psychology, and neurobiology focused exclusively on males. In response to the overwhelming need for information on the female mind, Brizendine established the first clinic in the country to study and treat women's brain function.

At the same time, the National Institutes of Health began including female subjects in almost all of its studies for the first time. The result has been an explosion of new data. The Female Brain, the book, is to be released on August 22nd, but you can also go on line at Amazon and preorder it, I understand. It distills all this information in a highly accessible way in order to educate women about their unique brain and body behavior.

This revolutionary book combines two decades of her own work, real-life stories from her clinical practice, and all of the latest information from the scientific community.

Please join me in welcoming Louann Brizendine.

DR. BRIZENDINE: Thank you, Bodie. It's fun to have someone else with such a rare name, to have a name like ours to share with someone. It makes you feel like family anyway.

Interestingly enough, I don't mean to say that all this research for years and years wasn't done on women for a reason, but all of you remember the horrible experience of the thalidomide years. Remember the drug that was used all over Europe and had terrible birth defects in children? That's one of the reasons that this country basically didn't do research on women for many, many years. That's changing now, but the NIMH has now required that all studies include women unless there's a specific reason not to. And the only type of example given about a reason not to, is if you are studying something that has to do with testicles. And you can then explain in your little application, "Females not included because they do not have this particular organ."

After having grown up in a family where my mother was a schoolteacher for 40 years -- she taught kindergarten -- I have a great deal of respect for all of the teachers in the world in a different way than some people might, and I really honor your practice. I would like today to share some of my field with you all and see in what ways there might be some interface. I want to present some information at the beginning, and I would like to leave time at the end for some exchange and questions that might help hone this down to things that are applicable more to what you all do as heads of schools, since I know you often have to deal with very difficult parents, as well as students, and how to talk with parents. Of course, in my office, I'm often talking with parents about their already identified -- usually by the school -- teen girl, who ends up coming, so I already have the advantage of having you all at the school identify that this particular young lady needs to come with her parents to the school. So you have already done the hardest part of the job by the time they get to me. You have already primed them.

(PowerPoint slide.) Note: E-mail NAPSG for a copy of this PowerPoint presentation napsg@mac.com

So these are what I call our customers. Here's a group of our customers. (PowerPoint slide.) And the social group, of course, at the school. This is obviously a co-ed school, which makes things interesting for girls, in that they constantly have the reminder that there are boys around. They may get fussier with their parents as a result. (PowerPoint slide.)

I'd like to talk a bit about the brain. Peel back the hair, the skull, and peer into the brain of a teenager. This is a nice picture that's a combined picture that shows the inner color structure there of the teen's developing emotional system looked at by PET scan. I would say that the new information that's coming out of all of this high-tech imaging of the brain is helping us understand some of the differences in many brains, but particularly the differences in male and female brains and what's the difference between the two.

Don't let people fool you, though. We're not quite at the time where we can actually read minds by this new technology. We're at least a decade off from being able to do that. (PowerPoint slide.)

So what's really going on in the teenager's brain? I'd say the bottom line, the take-home message for you all is that all of the latest research on brain development in adolescents shows that their brains are still being wired and that their thought processes are not fully mature. We were talking at breakfast with a group concerning the fact that teens get in your face with a level of certainty that they know. And that level of certainty can often be a bit off-putting to adults. How do you counteract that certainty?

One of the ways that you do it is having more patience, knowing that they're not all completely hooked up yet, and that it is a process that takes a very long time. (PowerPoint slide.)

Let's go back for a minute. I want to tell you how we think about brain development in my field, beginning with the fetus and proceeding through childhood to teens. I'm going to give you the bottom line here, which is that these brain circuits are all formed according to the blueprint of the genes.

Of course, we all have different genes. It's not just male and female that makes the brain different, but many of our individual genes. But then they are very highly shaped and activated by the hormones. The hormones come on to shape the brain on the blueprint that the genes have laid down, and that is what ends up flipping the switch on for maleness or femaleness.

Believe it or not, the male and female brain starts to be formed at about eight weeks' gestation. So that's almost before a woman knows she's pregnant. She finds out that she's pregnant right about the time that the gender of her fetus has been determined, between eight and eighteen weeks. So by the time you get into that second trimester, which is the three-month to six-month period, the gender of the brain has already been formed.

Girl brain circuits are different than boy brain circuits, and that's probably not surprising to any of you in this audience who educate both. We think about three major periods of brain growth. (PowerPoint slide.) All that's happening in the fetal brain, when the circuits are all being laid down, some are being activated during fetal life, and a little bit from zero to three years. There's lots of brain growth, and lots of you probably know about the big push in this country about the zero to three-year-old interventions to try and enhance the environment and enrich the environment as much as possible, have as much interaction as possible with parents, having parents maybe go a little overboard -- maybe some of you have experienced that -- where they have them listening to foreign languages all during the night while they're sleeping at the age of three. That may be a little overboard.

Then two years prior to puberty is a period of time that has only recently been realized as a major new period of brain growth. There are new cells and new extensions of all the branches of the neurons in the brain. That period starts about two years before puberty. This incredible flowering and blossoming in the brain starts to happen.

And of course, since puberty is a couple of years earlier in girls, this happens very early in girls, as we'll see in a few minutes. But the important thing to remember about this is that this process of growth and then pruning and reinforcing certain circuits and having other circuits die off is continuing up until about the age of 20. So it's probably not finished until the early college years. Even though there's great certainty coming out of the mouth of our young teens, and even older teens, the circuitry is not completely plugged in until around the age of 20. Actually, it's about 22 in males, and maybe 19 and a half or 20 in females. (PowerPoint slide.)

Let's look at this through the life span. (PowerPoint slide.) You can see that this is about the hormone pulses in the brain that start with fetal life. That big first peak there -- birth happens right in the middle of this big hump up here. And see that nice flat period there? We call that the childhood pause or the juvenile pause, which is an interesting quiet period that fascinates scientists, how the hormones in the brain get turned off at that period. The ovaries and testicles are put at rest for a number of years until the pulses start to again ramp up as puberty begins.

In girls, this ramping-up of the brain's pulses of hormones that are going to increase the growth of all those circuits starts to happen about one to two years before the onset of the first menstrual period. So we'll take a look at that. It's important to remember, because the parents of the girl may not identify that their child is really in puberty a few years before some of the other external body signs of puberty. And it's almost like the brain is being electrified up there by the hormones. So all these circuits are being switched on. What we call gender- or sex-specific circuits get switched on. So all of that hormone is estrogen and progesterone in females, and it ends up being testosterone in the males. So those circuits which are going to be sex-specific really get turned on at that early puberty stage. (PowerPoint slide.)

Now, this is a little photomicrograph of cells in the brain that are starting to respond to sex hormones. You can see how they're all lit up. You can see that as puberty starts to turn on the hormones in the brain, all of these cells become really electrified and turned on, just as if you turned on a light switch. So when hormones start to pulse, all these cells in the brain are starting to lights up. You can look at eight- and nine- and ten-year old students and know that that's what's going on in their brains, the lighting up of your girls. Boys are a little bit later. It starts to happen at maybe about ten in boys. (PowerPoint slide.)

Let's take a look at what's happening with the hormones in the girl. Remember, the pulsing of the hormone in the brain is going down to the pituitary and turning on the ovary. And the ovarian hormones -- the estrogen and progesterone cycle -- are going to marinate the girl's brain in waves, and those little brain cells that you saw turning on are going to turn on in waves. They're going to go up and down, and go up and down through that four weeks of the menstrual cycle.

Let's take a look at how that's happening. (PowerPoint slide.) See that first big peak that's called estradiol? That's the type of estrogen that the ovary makes. That's marinating the girl's brain in the highest peaks of estrogen that first couple of weeks. You see where ovulation is, right there in the middle? Up until that point, that first two weeks, there's no ovulation, there's no progesterone. So progesterone doesn't come on to complicate the situation until the last two weeks. The last two weeks for girls is where a lot of the action is. Their appetite increases, their desire to sleep more increases, there is increased irritability in some girls, and also increased responsiveness to stress. So your A-plus-all-the-time girl student who gets an A minus in this first two weeks of the cycle may be okay with that. In the last two weeks, she may burst into tears and feel like the world's against her.

There are certain aspects of all those little brain cells that light up that also switch on and off according to what the hormone is. I think that's a worthwhile thing for parents and teachers to know. It's obviously important for the girl to know about herself. Most of us women don't really know how this works for us individually until we're in our mid-20s and we sort of get with the program and know what's going on. So it's important to know about these waves of marination in the girls.

Remember, these waves of estrogen start about a year before the first menstrual period. Until you have menstrual periods, though, you don't have any of the progesterones, don't have ovulation, so for the year before that, what is estrogen doing in the body? Let's take a look at what's happening. (PowerPoint slide.)

I went over all of the data that's carefully been worked out by Marcia Herman-Giddens from huge databases in this country from 1999 to 2002. I think it's helpful to look at that time period, because there's a feeling that puberty is happening earlier because of our nutrition and the fat in the body, in the girl's body, which actually has something to do with turning on those brain circuits that start to pump out the estrogen. It says to the brain that the body is ready for pregnancy. It's giving the brain a little message that, yes, there's enough food around to sustain a pregnancy.

Now, you don't want a nine-year-old in that situation, although as Reveta can tell you, there's a whole group of girls ages 9 to 13 in LA in the girls' home who are pregnant between the ages of 9 and 13, so it certainly does happen.

Let's take a look at this. (PowerPoint slide.) The onset of breast development is the first thing, the breast bud, in girls. That estrogen that's pumping out from the ovaries starts to create breast buds by the tenth birthday in 50 percent of girls. So remember, the mean is always somewhere in the middle. So 50 percent of girls by the age of ten have developed breast buds. But it's important to know for your group that actually by age 8, 30 percent of Caucasian girls have breast buds. And in African-American girls typically, on average, the mean is ninth birthday, 50 percent of them have it. But by the eight-year-old birthday, 40 percent have breast buds. That means that the hormones are pumping out in the brain, going down to the ovary and making the estrogen pump out to stimulate breast growth. 40 percent by age 8.

Now, in the United States we call that third grade. So that's not too soon to at least have educators and all of us aware, when we're working with that age girl, third, fourth, and fifth grade -- can you imagine what's happening in their brains? Their brains are electrified with hormones. We don't think of it that way because they don't look very big yet. They look like they're sort of in puberty, and I think parents have a hard time with this, too, especially if it's their first child. They don't want to think about it. Teachers don't want to take it too much into consideration, but I think it's something to have in the back of your mind that's going on.

Pubic hair growth is what we think of as going into the second stage of puberty. For Caucasian girls, (PowerPoint slide) half of them have it by ten and a half, so that's more fifth grade. For African-American girls, it's age 9. Fifty percent by age 9. (PowerPoint slide.)

Menarche is the technical name for the onset of the menstrual period. In Caucasian girls age 12.6, half of them have had their period by then. But remember, that means also 30 percent have had it by age 10. I don't know too many schools that are really set up at age 10 to deal with Kotex, Tampax, the necessities. And actually, you all are in a more fortunate situation, in that you can make changes quickly in that arena, whereas certainly I know the public schools have no nurses, no counselors, no librarians. Maybe the school secretary for the girl to turn to if she was having a problem. I guess these days she'd turn to the cell phone and call her mother.

For African-American girls, 50 percent by 12.1. That means 40 percent of African-American girls have started their periods by age 10. Remember, the year before the onset of the period, the girl's brain is in full-blown puberty and her body is lagging behind a little. (PowerPoint slide.)

Breast stage 5 is considered a fully developed female figure. Caucasian girls, 15.5. African-American girls 13.9 is the mean. Lots of girls probably are age 12 that are fully developed and wear the same bra size they're going to wear when they're 25.

These are things we can all visually see in the girls. I'm telling you the back-story about what's going on with the brain. Once you see those signs in girls, you'll know that their brain has already entered into that pubescent stage. (PowerPoint slide.)

(PowerPoint slide.) Let's go back to the brain for a minute and check out what's going on sort of under the skull. (PowerPoint slide.) A doctor named Jay Giedd at the NIMH has done a lot of this work. They're continuing on with this work, scanning the brains of 145 teens each year. He has a study that looked at them from three years old up to 18 or 19. He has discovered that the teen brain is in a massive architectural reconstruction project. It starts in girls between age 8 and 10.

Now, what does that mean? Let's take a look at a little bit more. (PowerPoint slide.) It means the teen brains won't be thinking logically or rationally, like adults, until they reach their early 20s. Of course, this is not good news to teens. I think it's helpful for us adults to realize that that big person in front of us speaking to us with all levels of certainty doesnít know that their brain isn't all hooked up yet. Girls' brain circuits are more sensitive to stress during the last two weeks of the menstrual cycle. It's worthwhile to keep that in mind. And Pat from England has got ages 11 to 18? Are those your girls? From 11 to 18, they're all in this stage. If you've got 1,000 girls in your school, probably every week a fourth of the girls in your school are in this period of increased sensitivity to stress.

(PowerPoint slide.) There are two areas of the brain I want to talk about. I talk with parents about this, and they find it helpful to know a couple of things. These are their landmarks for what's going on. First is the prefrontal cortex, which is an area right behind the forehead; and the amygdala, which is right inside the ears. I'm going to talk about those two areas and what is happening in this teen brain. (PowerPoint slide.)

The prefrontal cortex is right behind the forehead here. Let's see what it does. (PowerPoint slide.) The processes that happen here are planning, organization, complex thinking, assessing risks and benefits, consequences of behavior. How many teens are really up on what the consequences of their behavior are? Just about zero. Delayed gratification, future-oriented goals, goal-directed behavior and control of impulses occur in that area. So what area do you think is not yet developed in the teen? I like the consequences of behavior for you all, because I know, as Heads, you often deal with that when it's not working in one of these teen brains. (PowerPoint slide.)

The reason that adults act adult is because they can use the prefrontal cortex, abbreviated PFC, to process information and make well-reasoned decisions. So that's what we all in this room can do at least 90 percent of the time, let's hope, and what we need to help that teen brain do. And parents need to be helped to help often. Sometimes when I find myself as a physician doing is help the parents get a concept of what their job is based on what the teen brain cannot do. (PowerPoint slide.)

Let's look at what is working pretty darned well in the teen brain. It's called the amygdala. If you put your hands right on top of your ears, right on top of the earlobe, if you were able to push your finger into your brain up to the second knuckle there, you would hit the amygdala. You have one of them on each side. The brain comes in two's, pretty much, just like the lungs, the kidneys. It has everything in two's. So this is just showing one of the amygdala on the right side of the brain. (PowerPoint slide.)

What does the amygdala do? "Amygdala" comes from the Greek word for almond. Amygdala. That's how it got that interesting name. The amygdala is the center of emotional impulses and instinctual behavior. So it picks up fear, picks up all kinds of intense emotions that are going on in that little area of the brain. It's about the size of an almond. And it's the home of sexual impulses, the desire to be sexually attractive in girls. We think actually the expression of sexual impulses in girls is how they become so obsessed with how they look to boys. I think that even if the media didn't exist -- the media puts a spin on this -- girls are going to want to be attractive to boys at this stage. It's like a hard-wired process in the amygdala. Boys are going to look at girls and look at pictures of girls and chase after girls, whether there's a media or not.

So this is the area for sexual pursuit in boys and the area of sexual attractiveness as you think of it in females. It can get a little overdone with the image in the mirror in some of these girls. (PowerPoint slide.)

As the prefrontal cortex matures, the extension cords that connect the amygdala (those two things about the size of an almond behind your ears) to the prefrontal cortex (where decision-making happens) finally get plugged into the right sockets and teens can reason better. The brakes can be put on, so to speak, to the instinctual impulses that are pulsing out from that amygdala. This process will happen one to three years earlier in girls, by age 17 to 19. They're pretty much all plugged into the right circuits, you know, but before that, it's intermittent.

I was talking at the breakfast table with a group from Massachusetts about how you get so frustrated from time to time. "I just told you that yesterday." Or you know, "You seemed to understand it yesterday. What happened today?"

It's this repetition, repetition, repetition. And you think they have got it, but they don't quite have it. Some of this is, of course, volitional. This is not to excuse all teen behavior. But some of what feels so frustrating to adults is because it needs reinforcing, needs repetition, because it's not quite there yet. It's not quite plugged into the right circuit.

(PowerPoint slide.) These are the synaptic branches, what I refer to as the extension cords, growing wildly in the teen brain between the prefrontal cortex and the amygdala, and they're not securely plugged into the right outlets yet. (PowerPoint slide.) So you can think of the PFC as a power strip, and things are gradually getting plugged in there. But in the teen brain, they may be in the wrong circuits and need to be wiggled around to get them in the right circuits, and that only comes from practice, practice, practice, repetition on the part of an adult brain that can already do this.

Sometimes explaining this to parents is also really useful, because it helps them back up and then look at their big, gangly kid who looks like an adult and say, "Okay, yes, some of their behavior is bad behavior, and I have to be more present in their life to help put the brakes on." (PowerPoint slide.)

So the bottom line is that adults must provide the brakes until the teen brain can do it alone. So that's the message I often give to parents who come in. Trying to figure out how that particularly applies to that individual girl is complicated. Sometimes they need to be kicked out of school; right? There are times when that is not a bad idea. It's an extreme mode, but I think that sometimes it's even better for the students themselves, when they have such bad behavior, they have gotten such a bad rep with their peers that it's only going to persist if they stay with that peer group. So you adults have to make those hard decisions. (PowerPoint slide.)

Now we'll talk a little bit about something else that's happening in the teen brain. This is the 8:00 a.m. class with the typical teen girl. These teen brains really are not able to wake up as early as we are. (PowerPoint slide.) Staying up late and the teen brain. Getting out of bed. I have a 16-year-old son living in my house. On the weekends, if he's out of bed before noon, this is a miracle. On weekdays, he has to be up and out. He's lucky he doesn't have to be up and out and start school -- it's just down the street from our house, until about 7:15 or 7:30. Their school starts at 8:30. They think of themselves as being progressive, so they're thinking of doing a 10:00 to 5:00 schedule, and then switching the teachers meetings to being the 9:00 hour and the kids start at about 9:30 or 10:00.

At any rate, let me tell you why this might be something that we will see happen more and more in schools around the country. In Colorado there's a big movement in the public high schools to do this. (PowerPoint slide.)

There's something called a chronotype. Some of you are probably morning people. How many are morning people, consider themselves morning people? I think heads of schools probably are selected for -- at least you're adaptive. How many of you think of yourselves as night owls? Okay, there's a group of night owls in here. I think the people in my medical school class that went into surgery all had to be the early types.

But children are usually what are called early chronotypes, so those of you who raised your hands for the early wakeup people are early chronotypes. And obviously, there's some variation in population. And they go to sleep early, get up early. But as puberty approaches, the brain's chronotype gets progressively later and later, delaying sleep. It's really hard. We have a rule in our house that lights are out at 11:00. Well, this is theoretical, of course. I think lights are out at 11:00, until the parents leave to go back upstairs to their room, and probably the lights go back on and the TV goes back on.

But it's very hard for the teen brain, as it gets more and more into puberty, to actually fall asleep and go to sleep at the same hour as they did when they were children. So 8:30 or 9:00 may have been their bedtime when they were 8, 9, 10. For girls, this starts to get later and later by age 10 or 11. You know how the hormones in the brain are changing the brain, all those little brain cells are lighting up as the hormones start? Something starts to change the set point for go-to-sleep time and wake-up time. So the teen brain, probably by 15 or 16, is quantifying to go to sleep at midnight or 1:00 and they really aren't even awake to pull themselves out of bed at 8:00 or 8:30.

My high school was on a very early schedule. We were on a split schedule in California because we had too many students. My chemistry class was at 6:45 a.m. I don't think I learned any chemistry that year. At any rate, that's cruel and unusual punishment, for the teen brain especially. (PowerPoint slide.)

So the teen brain is not alert and ready to learn typically until around 10:00 a.m. I think that's important to think about, just in terms of what times of day teens are having problems. (PowerPoint slide.)

Now, at least in the United States, this has become a very topical issue. Has anyone heard of a fellow named Larry Summers? He used to be president of Harvard. He will be until June. He's recently resigned. I guess last week he resigned over this very issue. He didn't exactly say the female brain is innately not able to do science and math as well as the male, and that's why there are fewer females in top levels of science and math in this country, or in all countries.

But let's think about this for a minute. It's a very complicated issue, and it's landing right in the middle of the neuroscience field that I spend a lot of time studying. Whether or not this is true or how this is different, I'm going to give you a way to think about it, based on the current science. (PowerPoint slide.)

Let's look for a minute at the male and female brain circuits for solving math tasks. The highest difference that neuropsychologists have discovered in looking at the female brain and male brain doing something in particular different -- you know those three-dimensional objects that you have to be able to figure out on the IQ test? They give you one, and say, "Which of the four below it is the same as that one?" Males do that much faster than females typically. That is probably the most robust sex difference in terms of cognitive processing.

Let me show you what happens when the male and female brain do that. They both can come up with the same answer if it's an untimed test. Watch this. (PowerPoint slide.)

This is from a study done in 2002 out of Germany. So the one that says "women," which you may not be able to see, but it's on your left, and the male brain is on the right. Number 1 is where the process begins, in terms of looking at the circuits that light up. In the male and female brain, they both go to number 2 next. The female brain then goes back into another area, into that area 3. And the back of the brain, you know how if you get hit hard, you see stars? The back of the brain is where the main visual centers are. The female brain spends some extra time twisting that object around visually, for whatever reason, and then it goes back to areas 4 and 5 and comes up with the answer. But that extra step takes some time, so it's not as fast. You end up with the same answer if you do an untimed test. In the math part of the SAT tests, males typically do a bit better. Actually, if you do untimed tests, males and females perform exactly the same.

That's not entirely true for the verbal tests. The verbal is higher in the female. Even if you give males extra time, they don't necessarily get the same scores as females. So I guess the centers for yacking in the female brain are very hard-wired.

(PowerPoint slide.) Let's look at a culture. Let's look at something in Iceland. They have more girls that are good at math. Girls are better at math in the grade school levels often, and as the math courses get harder and harder, the males, at least in our country, get better and better and the girls stay the same. But in Iceland, it's interesting to watch because the girls are better in math. Those who have studied that culture come up with one thing. How many of you have heard of this particular study of math and girls in Iceland? A few of you. Well, what really counts in Iceland in terms of what the boys want a girl to be, where the money is, is in the fishing industry. And so all kinds of things that have to do with that particular industry are where the really good jobs are, that pay really well.

It's interesting how the boys are all focused on that, and they do more poorly at math. They don't take as many high-level math classes as the females. It's kind of the reverse of the United States, where more boys take the high-level math classes than the girls. But in Iceland, the girls are the ones taking more high-level math classes because the jobs available to them that are higher-paying end up being jobs, not necessarily in engineering classes, but they have more technical jobs for females.

(PowerPoint slide.) So that gives one pause, doesn't it? Is it a matter of motivation? It seems to be a matter of motivation and not lack of talent or brain circuits. (PowerPoint slide.) So practice, practice, practice in everything seems to make the brain better. (PowerPoint slide.) Girls who take more math and science classes appear to be equal to boys who do the same. There will be a lot of thinking about how to teach math differently to girls to have them be interested in it. As you can see, the teen brain isn't always focused on their own future. They're focused on what's cool to them now, what their girlfriends are doing, what their parents are doing. If only the nerdy girls, the girls who are not considered cool, are taking these higher-level math classes, you can see where the culture goes in a high school.

Reveta and I were talking about getting girls to keep a math journal, keeping a math diary. "Dear diary." If they would write something, there might be more creative ways to capture a girl's interest in teaching math that we might think of. If you look at the percentage of teachers of math and science throughout all the high schools in the United States, and look at the gender breakdown of the teachers, how many are male versus female? That's sort of a no brainer. It's hugely more male than female in the country at large.

So I think there is something to be said for having a role model and having math be something that becomes interesting to girls, as well as being interesting to enough girls that it becomes critical math. In the two or three years before I went to medical school, there were fewer women in medical schools. When my husband went to medical school, there were only five or six women in his class at Columbia Medical School. In my era, at Yale, we were 30 percent women in my class. That's called critical mass. And now it's 50, 55 percent female in medical schools, so it's really become critical mass.

Until that starts to happen, you have a social problem and the issue of girls not doing as well in math and science then goes to a different level. How many 85-, 95-hour weeks can you spend after you have a couple of young children at home? So you have an area where women's careers plateau out in the years they have young children. A lot of you mothers in the room know the level at which you need to be available to the kids once they're out of the house. That changes the formula entirely. I'm looking forward to that day. (PowerPoint slide.)

Girls' and boys' brains may solve the same problem using different circuits. If I give you any message about what's different between the male and female brain in terms of how it does lots of things. I just focused on this one little area, the teen girl brain, but if you look at all aspects of reading emotions and faces and the emotional intelligence of the female brain, there are many more different circuits that females use in their brains for emotion than males. They may come up with the same answer, and you may be able to be trained, but the circuits are different. (PowerPoint slide.)

Motivation and interest in math and science is the key to success for both boys and girls. This is something that we can all say is clearly true. (PowerPoint slide.)

So on that happy note, "You go, girl," and powered by the female brain. Thank you all. Any thoughts from anyone? We have lots of mikes.

MS. SULLIVAN: Have you done any research about girls who delay their periods because of eating disorders and how that affects their reasoning abilities and their maturation?

DR. BRIZENDINE: The question is, girls with eating disorders, not necessarily bulimia so much, but it happens in anorexia. They decrease their body weight. Are any of you at schools where you have a high athletic program where you have girls who are very underweight or in dance programs, or gymnastics in particular? Gymnastics girls are notorious for this, being very underweight.

One of the things that triggers the brain to say, "Okay, it's okay to go ahead and start puberty," is the fat cells in the body. And estrogen starts to pulse out and stimulate fat cells to grow in what we call the normal female fat distribution. Those girls may not have that for a while if they stay very, very thin and the body is using up so much energy to do their athletic things or the body is not getting enough energy, if they're anorectics, to put on body fat. So that whole process in the brain is delayed. Yes.

The pulse process of puberty can be accelerated by high nutrition. As we've seen in this country, the age of puberty kept going down until the mid-1950s, when the average person in the population had the maximal amount of nutrition. You'd think it would be more now, because we have a lot of obesity in kids. But the age of puberty seems to be limited by good nutrition. But by bad nutrition you can also pull the age up, so girls may be 16. You see girls who are really, really thin, and then you see, too, that the average age starting the brain into puberty for a girl may be like 10 or 11 years old. These girls who are ultrathin may pull that process down and may not start until later. So they're late developers. Lower energy. If they're caloric restricting, then their brain isn't going to have enough calories to really concentrate very well. So that's a problem in terms of their academic achievement sometimes. I'm sure you have all had girls with anorexia in your programs.

SPEAKER FROM THE FLOOR: I have a question about the PFC, which I recall was the center of brain --

DR. BRIZENDINE: Which you have all hooked up, probably.

SPEAKER FROM THE FLOOR: -- which has to do with making judgments and being smart and decision-making. Is there any way of stimulating that or of channeling it? Any external things that we adults might apply to our children?

DR. BRIZENDINE: In terms of how the brain develops, you know, you practice, practice, practice. There used to be classes called civics, or philosophy, or teaching ways of thinking about moral behavior. You know, a lot of religions help with this, because there are ways to behave and ways not to behave. So there are all kinds of things in our society and our culture that can help with that, with improving that process and helping to put the brakes on for the teen brain during those years where it needs to learn that.

So the answer to your question is: We don't have any way of showing that in science. I mean, it would be an interesting project, but it would be very expensive to do that type of project, where you took one group and provided some kind of learning environment where they learn to make good judgments, and whether or not that actually helps the brain hook up faster. One would predict that that might indeed be true if you were able to teach it and train it.

SPEAKER FROM THE FLOOR: I was wondering if you might comment, if you can, on the short- and long-term effects of drugs and alcohol on the developing teen brain.

DR. BRIZENDINE: Bottom line: It's bad. One of the problems, as you can see, is that as all these brain cells are putting out all these connections, the brain has to be able to reinforce some of them, which will survive, and the ones that are not reinforced are going to die away. Which ones you keep and which ones you don't keep make a lot of difference. So one of the things about the teen brain that all of you are front and center being able to influence is that it's the time of life where you can influence the next generation the most.

If you have got a brain with nicotine, drugs, alcohol, whatever, you're probably not helping that process. The teen brain seems to be more susceptible, especially the teen girl brain in the last two weeks of the menstrual cycles. There were some studies done on girls who are addicted to various drugs, including nicotine. Their biggest time of relapse is that last two weeks after ovulation. So concerning relapse in teen girls, even after they have been in a treatment program, their most dangerous two weeks of the month are those two weeks. That's a great question.

SPEAKER FROM THE FLOOR: Following up on Anne's question, it's my experience with children who are extremely focused athletes and probably ovulating very late in their lives, if at all, or children whose body fat is off for whatever reason, in fact, are the top of the class. They are the most driven and the most focused. I'm not saying their judgment is any better or any worse, but these are the ones going to the Ivys for various reasons. These are amazing kids. And you find out later, sometimes, you know about the athletes, but when they come --

DR. BRIZENDINE: You don't know about the eating disorders. They're sometimes very secretive. The issue of self-discipline varies in the culture. How many of you consider yourselves a self-disciplined person? Probably all of you do. You wouldn't be in this room, otherwise. But that has a bell-shaped curve in the culture, probably, too and those girls you're talking about are way up there. They're probably going to be in this room someday, some of them.

There's a level at which restricting your calorie intake requires incredible self-discipline. So my guess about those girls is that they are on the top level of that curve to begin with, and some of them can do some pretty self-destructive things and fall off of that place on that curve. Those are the ones who usually end up in my office, but a lot of them just go on and forge straight ahead and they're super women for a lot of their lives. And they may get some time to pause at that point, but they're on the part of the curve that's way up there in terms of self-discipline, self-control, and IQ points, et cetera.

SPEAKER FROM THE FLOOR: I was intrigued with what you said about schools that are thinking about going from 10:00 to 5:00. And of course, it's very hard for a school to decide to do that by itself. And I think about athletic programs, and I wondered whether anybody here had been in conversation about doing this, because if a number of schools got together and did it, it would be possible, I think. I'm just curious.

DR. BRIZENDINE: That's a good point. What I found when I have talked at different schools is that it makes good sense to deliver a service to your customers. You're trying to deliver learning; right? And to do that in a way that's going to be at their best part of the day for absorbing that is going to be good for them and the teachers and it's very bad for athletics, extra-curricular. There are all kinds of problems with that. What happens in a school, it you do 10:00, they'll swap the extracurricular things to the morning time, right?

So you can see that that would happen in all your schools if you did this. You'd have your teachers meetings in the morning, faculty meetings in the morning, whatever, and all your coaches and extra-curricular would swap, to do the 9:00 or 8:00 or 7:00 hour. So it's very complicated about when to do that. It's better to do later things with kids, though, for example. We adults don't want to be there at 7:00 at night. The kids, though, will do fine with that.

SPEAKER FROM THE FLOOR: I can't wait for your book to be published so I can buy one for every one of my faculty members. My question comes down to having raised two boys and then a girl, I learned everything I needed to know about life in raising a girl. And in that process, I'd like to know what previous research you depended on to help you develop your concept in understanding what girls are going through in their development. I know there had to be some research out there, but I'd be interested to see how you formulated your research.

DR. BRIZENDINE: The book has 950 references, just to give you an idea. As my husband says, it's way over the top, but my publisher didn't seem to think so. There's a huge body of literature that does sex differences in everything, from the get-go. The work of Eleanor Maccoby, out of Stanford. She's in her 90s now. I have had several conversations with her along the way, just to make sure, according to her words, I was getting everything right. She's a wonderful person. She wrote a beautiful book in the late 1990s called Between the Sexes. Her work is mostly in age 3-year-old to 8-year-old. She has lots and lots of very lovely studies about boy play and girl play and the communication between them.

A little girl is sitting there, 3 years old. Two of them together are playing dollies. One has a dolly in her lap that the other one wants. And the other little girl that would like to play with that says, "Oh, well, if you're not using that right now, could I borrow it and give it right back?" And of course.

Now, a little boy who would like a toy that another boy is playing with -- that verbal negotiation is probably not what he's going to do. Whack, and he's off and running.

So that little vignette shows you that girls do all kinds of things or use their verbal skills often to do things differently. And I'm sure you have seen that with raising your children, and we all see that in boy/girl negotiation all through our lives. There's a different level or type of negotiation. Those of you men in the room probably have very high verbal skills to be in this particular field. Of course, there's that bell-shaped curve for that, too. So there are huge amounts of literature.

The brain scan studies and the brain EEG studies of 2-year-olds and 3-year-olds, young children, are hard to get. You have to lay real still in an MRI. Has anybody ever had one? I have had a couple, and you have to lie very still for a long period of time. And you can't get a 2- or 3-year-old to do that for an hour to get a brain scan.

So this information is coming to the fore very slowly in terms of research, and that's why I bring out Jay Giedd's work at the National Institute of Mental Health because he's been doing the bulk of that kind of work, which is painstaking, slow, and you have to find ways to trick the kids to be still enough to perform.

SPEAKER FROM THE FLOOR: I'd like to circle back to your question about girls and nutrition. I'm curious about young women in other cultures and how the pattern changes in other parts of the globe, and age development, brain development.

DR. BRIZENDINE: Did everybody hear the question? It was about brain development in different cultures where there are different kinds of nutrition and probably body types. There is anorexia in every culture. It's thought to be several percentage points higher in ours. The explanations for this are not scientific evidence; no real reason has been nailed down. Most of that is laid at the feet of the image of females that's presented as: Being thin is better. Our culture pushes the envelopes in that direction for girls wanting to be thinner, wanting to be like the models in the magazines and constantly comparing themselves to the mirror. Some girls, by the time they're in their 20s, don't even have any mirrors in their homes, because of the obsession with the mirror. You have to have many bathrooms if you have several teen girls in the house at once. You can never have enough mirrors for a teen girl at a certain stage.

So I think you can shift it, in terms of your cultural values about what is beautiful and attractive, because that part of the female brain is very hard-wired. She wants to be attractive. She wants to measure up. She wants to be good enough. There's the striving during the teen years: Am I good enough? Am I normal? Am I going to be able to make it in the world? Am I going to be attractive to boys? That whole process. Girls spend a lot of time thinking about those issues and trading secrets about that and comparing themselves to the magazines or to now, I guess, to all of the Internet images. Maybe myspace.com is not such a bad thing for some girls, in that they can do it in words better, but now they're posting all their pictures on the net. It's a new level of obsession with how you look and posting it for the whole world to see on your myspace.com site. I'm sure you all are watching that endlessly.

SPEAKER FROM THE FLOOR: I'm fascinated by that period when the brain is quiet.

DR. BRIZENDINE: Juvenile pause.

SPEAKER FROM THE FLOOR: Yes. Does that have any implications to be studied for elementary education and what we do or don't do in terms of pushing elementary children?

DR. BRIZENDINE: Well, it means that that's a blessed period of quiescence. Usually the parent/child relationship is a little bit less difficult at that stage, in terms of their education.

SPEAKER FROM THE FLOOR: I was thinking more about schools and expectations and how hard, in some cases, parents and schools are pushing kids in those years.

DR. BRIZENDINE: This is my opinion. I don't have any science behind this. This is my opinion, having had a child in high-pressure schools in San Francisco, which I'm sure is somewhat similar to all of your schools.

I think kids need some time to integrate. There's this thing called the gap year. You all have heard, of course, of the gap year, this movement to take a year after you finish high school before you go to college, to slow the process down a bit and be able to integrate some of this material.

I think we don't give any space for integration. We send kids home with four hours of homework in the fourth grade -- I mean, come on -- with no data, by the way, scientifically that that helps, that anything over one hour of homework does anything. The teachers cannot go over that much homework in the classroom with the kids. You kind of wonder, what in the heck are we doing?

And schools compete. At least in my town, San Francisco, a couple of schools have three and four hours of homework by the fourth grade. Come on. And they compete. They don't consider themselves academically the most superior school in town unless they have got the most homework in town. It's crazy. But that's my opinion.

The only piece of data that's based on is that more than one hour a night is crazy. You get no family life. You don't get a lot of other things. You miss out on other things, and you make this intense relationship between the parent and child of pushing, tutors, and pushing the kid to perform on homework, and they miss out. That's my opinion. You break the brain. Eventually, these kids fall apart in college, of course, when they're out of the family. 60 percent of the kids at Stanford are on Prozac, so take that.

SPEAKER FROM THE FLOOR: Is there any research that has been done about the development of the prefrontal cortex and girls -- or boys, for that matter, who are dealing with attention deficit disorder --

DR. BRIZENDINE: There's lots of information about attention deficit disorder. Of course, you know, ADD, ADHD is a four-to-one ratio in boys over girls. Reading and learning disabilities in the grade school is four-to-one, boys over girls. So there's something about the male brain that is perhaps slower to develop. Fifteen percent of grade-school boys in this country are on some kind of stimulant like Ritalin. In Great Britain it may be 3 or 4 percent, so there's quite a big gap in that. So that may be some way that we're responding to trying to push our kids more in this country. I don't know.

But the development of the prefrontal cortex to different parts of the brain -- there are areas of the brain that are thought to be very, very important for attention, that just may take longer in those kids to develop, but there are reams and reams of studies, especially out of the Yale Child Psychiatry Department that are looking at attention deficit in both boys and girls. The boys tend to have more of the attention deficit hyperactivity, ADHD, and girls have the attention deficit disorder that doesn't include hyperactivity. They're missed often because they're not identified in the classroom. We rely on the teachers' information hugely in this country to give us information about what's going on in the classroom. And girls often don't have that level of hyperactivity, so they're not identified.

It's a real phenomenon that has something to do with brain maturation and the brain circuitry being different in those kids. Yes, there's lots of work being done on that. That's not my area of specialty. I certainly have been aware of that area since I have been working on this. But how to tweak that, how to behaviorally tweak that, rather than treating with drugs I think is missed in this country a lot, in that there are behavioral things that you can do to help a kid who has attention deficit, and I would vote for going to medications only in the real extreme cases where the child's self-esteem and social life are being ruined by their behavior. Because with the developing brain, when you're pouring drugs on it, that's not a good combination. That's my personal opinion about that.

SPEAKER FROM THE FLOOR: We see a lot of teens on line, IM'ing and blogging, and we have this generalized assumption that it's somehow changing their brains, but we don't know how. Are there studies and are there gender differences in the way kids interact with the Internet technology and what that does to their brain?

DR. BRIZENDINE: I guess this is a hot topic certainly for our generation that didn't grow up with the Internet. But clearly girls do instant messaging more. Girls are more involved in developing their most beautiful myspace.com, their own site there. Girls are doing more things in words on the Internet.

What are boys doing on the Internet? We have one in our house who does nothing but games, and there are now five or six colleges in the United States that have a major in gaming. You can major in gaming. Yes. And those kids graduate with jobs and salaries in the six figures, starting. So that's a whole new industry. So even though we thought it was a terrible thing to let him play these games, we're now thinking maybe he'll be supporting us. He can buy us motorized wheelchairs; right?

At any rate, to be more serious about that, I don't think it's doing anything that any other new technological advance in any culture hasn't done necessarily. We all worry and are nervous about it because we're worried and nervous about our kids to begin with. And too much of it is probably a bad thing. In my opinion, not allowing it at all is depriving them of something that's going to be part of their world when they grow up, and they need to have some experience and facility with it. So I don't think it's hurting them unless they do way too much.

SPEAKER FROM THE FLOOR: It's not changing the way their brains develop?

DR. BRIZENDINE: I think it probably is reinforcing certain circuitry. That's going to be part of the circuitry they need for their lives. I mean, that's one way to look at it in the positive light.

SPEAKER FROM THE FLOOR: As an English teacher, it lowers their level of discourse. Their IM conversations are not what you would normally have face-to-face, so when they have face-to-face conversations, they miss words.

DR. BRIZENDINE: I see. In other words they're doing text messaging in their speech now. Thank you for that. I thank you for educating me about what's happening to their discourse. We should probably go back to the British model of standing up and giving oral dissertations. It wouldn't be a bad thing. That's something you could put into your English classes, or giving more speech classes and teaching proper elocution; right?

SPEAKER FROM THE FLOOR: When you were talking about girls being hard-wired to pursue being attractive and attracted to boys, what's going on for our gay and lesbian kids who are closeting that part of their life, and the development of prefrontal cortex in relationship to the amygdala? What's going on for those?

DR. BRIZENDINE: That's a very good question, and always a question I get from every audience I talk to about this. I'm going through typical, typical, typical, and this is a variation of the female brain.

There is no difference, actually, in what's going on in terms of sexual attraction to same sex. It's all the same. It's just that it happens to be that their sexual attraction is to the same sex.

There's a lot of work on the female brain and how that ends up happening. In terms of the development in the fetal life, it seems to be that there are some differences in the genetics and in the brain circuitry, and some differences in the female br

There's a lot of information on the male brain. The homosexual male brain is much more studied than the female, even though about 4 or 5 percent of the female population is same-sex attracted. So how that works in fetal brain development is not entirely understood.

For example, girls who have a lot of androgens, testosterone, in their brains, even though they're genetically female, end up having higher percentages of same-sex attraction. But the teen girl's brain is still working the same stuff. Of course, socially they're very shut down and there are a lot of gay girls who are out now in high school by that time, and there are some schools where it's okay to do that, or girls are experimenting with that, et cetera, et cetera. I'm sure you have schools where there's a core group of girls and some girls on the fringes who are experimenting with what their sexuality is.

So sexual exploration at all levels, of course, in the teen years is what's going on in the teen brain, and that's motivating them. Their judgment about things, no matter who they're attracted to, is often not the best.

I want to thank your group for being so kind to invite me.

MS. LEE: Thank you, Louann, we're all going to rush forward to sign you up to speak to our faculties.

We have a break. Please be back here promptly.

MR. GALBRAITH: Dr. Brizendine has agreed that her Power Point is available to you. If you will e-mail me, I'll send it to you. It will be up on the web site soon, as are all the proceedings. They'll be up in about a month. Www.napsg.org, and our e-mail is napsg@mac.com.

We'll break for 30 minutes. There's coffee and soft drinks. There's one space on the Ghost Walk, and about half a dozen on the walk around Charleston, if you're interested. We'll see you in 30 minutes.