HOW A GEEKY GIRL FELL IN LOVE WITH THE BRAIN: The Science of Neuroplasticity and Enrichment - Healthy Brain, Happy Life: A Personal Program to to Activate Your Brain and Do Everything Better (2016)

Healthy Brain, Happy Life: A Personal Program to to Activate Your Brain and Do Everything Better (2016)

HOW A GEEKY GIRL
FELL IN LOVE WITH THE BRAIN:
The Science of Neuroplasticity and Enrichment

Long before I wanted to be a scientist, I dreamed of being a Broadway star. My father, an electrical engineer and one of the most diehard Broadway fans you will ever meet, took us to every traveling Broadway production that came to San Francisco, just an hour away from my hometown of Sunnyvale, California. I saw Yul Brynner (when he was about eighty-five) in The King and I, Rex Harrison (when he was about ninety-eight) in My Fair Lady, and Richard Burton (kind of old, but not ancient) in Camelot. I spent my childhood watching Shirley Temple movies and all the classic Hollywood musicals. My dad took my brother and me to see The Sound of Music when it was released in the theater each year. We must have seen it twenty times. I fancied myself as a magical blend of Julie Andrews, Shirley Jones, and Shirley Temple, and in my daydreams, I would spontaneously break into song and, in my adorable, impossibly plucky way, save the day and get the guy—all in one fell swoop.

But despite my father’s love of all things Broadway, I was clearly expected to do something serious with my life. As a third-generation Japanese American with a grandfather who had come to the United States in 1910 and founded the largest Japanese-language school on the west coast, my family had high expectations for all of their children. Not that they ever verbalized these high standards—they never had to. It was simply understood that I should work hard at school and pursue a serious career that they could be proud of. And by serious, I knew I had only three choices: I could become a doctor, a lawyer, or something academic—the more impressive sounding the better. I didn’t fight these expectations; they made sense to me.

Quite early, in the sixth grade at Ortega Middle School in fact, I began a lifelong pursuit of science. My science teacher that year, Mr. Turner, taught us about the bones of the human body, testing us by having us put one hand into a dark box to identify a bone by touch. I loved it! No squirming for me—I was thrilled by the dare. I became even more excited when I got to do my first pig and frog dissections, and despite the revolting odor, I knew I had to know more. How did all those little organs fit so compactly and beautifully into that little pig body? How did they all work together so seamlessly? If this is what it looked like inside a pig, what might the inside of a human look like? The process of biological dissection captured my imagination from the first moment I got that choking whiff of formaldehyde.

The emerging scientist in me was also fascinated with that most coveted of candy concoctions when I was growing up: Pop Rocks. While other kids in my class were satisfied by the mouth-feel of explosions on their tongues, I wanted to understand what triggered these bursts and what wild sensory/chemical experiences you could have in your mouth by combining them with other things, like fizzy seltzer water, hot tea, or ice water. Unfortunately, Mom deemed these experiments a choking hazard and they quickly ended.

My high school math teacher, Mr. Travoli, lovingly guided me through the beauty and logic of A.P. trigonometry. I loved the elegance of math equations, which when done correctly could unlock the keys to a pristine world, balanced on either side of an equal sign. I already had a feeling that understanding math was a key to what I wanted to do (even though I had no idea what that was in high school), and I worked hard to get the best marks in class. In his lilting Italian accent, Mr. Travoli told us over and over again that we advanced-placement students were “the best of the best.” I took this as both an encouragement to excel and a solemn responsibility to use my math skills to their fullest potential. I was a serious and earnest kid, on my way to becoming an even more serious teenager.

By this time, the only outlet for my inner Broadway passion was going to the movies. I got my parents to agree to let me see Saturday Night Fever on my own by telling them it was a “musical” and conveniently failed to mention the R rating (I was only twelve). They were not pleased when they realized what I had seen. Later, I was obsessed with movies like Dirty Dancing, and imagined myself effortlessly stealing the show in Johnny Castle’s arms despite the fact that I hadn’t taken a single dance lesson since my ballet and tap days in grade school.

By high school, the balance had decidedly shifted. The shining lights of Broadway had dimmed, and I was a steadfast, committed, and driven student, completely at home in a life of total science geekdom. I can see an image of myself in high school: shoulders hunched, serious faced, and carrying a tower of heavy books, as I made my way through the hallways trying not to attract any attention. Yes, I still relived my Broadway fantasies every time I saw one of my favorite musicals on television, but by then those dreams were kept locked in the den at home and studious geek girl had taken over my life. I was entirely immersed in academics, getting straight As and getting into a top college. I had no time left over to even think about my whimsical interests, never mind letting them coexist alongside my devotion to science and math.

I was also painfully shy, never close to being bold enough to date anyone in high school. I was on the tennis team all four years, but how could I not be? My mother was an intense and active amateur tennis player who made sure I played tennis year round and sent me to tennis camp every summer. Tennis was supposed to make me more well rounded, but in reality, what I desperately needed was a camp focused on the topic of how to talk to boys. Well, I never went to that camp, and as a consequence, I also didn’t go out on a single date or to a single prom through junior high and high school. In other words, if there had been a Miss Wallflower USA contest for nerdy science geeks, I would have blown the competition away.

All those stereotypes about the geeky, dateless science nerd? I proved them true.

FROM BROADWAY STAR TO LAB RAT

Although my science obsession, good grades, and academic drive didn’t win me any dates, they did get me somewhere—somewhere good. While I didn’t know exactly what kind of science I wanted to pursue, I knew where I wanted to study it. The University of California, Berkeley, just a hop, skip, and jump from Sunnyvale, was my family’s alma mater. Yes, I toyed with the idea of moving away to college and even got into Wellesley way on the other side of the country, but I was in love with the beautiful Berkeley campus and quirky-cool vibe of the town and just knew that it was the right school for me. I applied and was successfully admitted, which made me officially the happiest girl in the world that spring. I quickly packed my bags and could not wait to start this new adventure.

It turns out I didn’t have to wait long at all to find my academic passion. It came in the form of a freshman honors seminar I took my very first semester at Berkeley called “The Brain and Its Potential.” It was taught by the renowned neuroscientist Professor Marian C. Diamond. There were only about fifteen students in the class, allowing for more direct interaction with the teacher.

I’ll never forget the very first day of that class.

First, there was Diamond herself. She looked like a science rock star standing at the front of that classroom, tall, proud, and athletic with a blonde bouffant hairdo that made her look even taller than she was, wearing a crisp white lab coat over a beautiful silk blouse and skirt.

Also, sitting on the table in front of Diamond was a large flowered hat box. After she welcomed us to her class, Diamond threw on a pair of examination gloves, opened the hat box, and slowly and ever so lovingly lifted out an actual preserved human brain.

The human brain.

(Courtesy of the author)

It was the first one I had ever seen in my life, and I was completely mesmerized.

Diamond told us that what she was holding in her hands was the most complex structure known to humankind. It was the structure that defined how we see, feel, taste, smell, and hear the world around us. It defines our personalities and allows us to go from crying to laughing sometimes in a blink of an eye.

I remember how she held that brain in her hands. This object used to be someone’s whole life and being, and she respected that awesome fact in the way she handled that precious piece of tissue.

The brain sported a light tan color that I later learned mainly came from the chemicals used to preserve it. The top part of the brain looked like a compact mass of thick, somewhat unruly tubes. It had an oblong shape that was slightly wider on one end than the other. When she turned the brain to the side, I could see more of the complexity of the structure, with the front side of the brain shorter than the back end. The divided and paired structure of the brain was obvious at first glance—the right and left sides of the brain were each separated into different parts, or lobes.

THE BRAIN AND ALL ITS PARTS

Neuroscientists used to think of the different parts of the brain as housing certain functions. We know now that that’s only partially true. While specific areas of the brain do have specific functions (see the following list), it’s important to keep in mind that all parts of the brain are connected, like a vast and intricate network.

(Courtesy of Ashley Halsey)

Frontal lobe: This front section of the brain houses the all-important prefrontal cortex (making up the front part of the frontal lobe), understood to be the so-called seat of personality and integral to planning and attention, working memory, decision making, and managing social behavior. The primary motor cortex, the area responsible for allowing us to move our bodies, forms the most posterior (toward the back) boundary of the frontal lobe.

Parietal lobe: This lobe is important for visual-spatial functions and works with the frontal lobe to help make decisions. The part of the cortex responsible for allowing us to feel sensations from our bodies (known as the primary touch cortex) is located at the most anterior (toward the front) part of the parietal lobe.

Occipital lobe: This is the part of the brain that allows us to see.

Temporal lobe: This is the part of the brain involved in hearing, vision, and memory.

Hippocampus: Located deep inside the temporal lobe, this area is crucial for the formation of long-term memories; it’s also involved in aspects of mood and imagination.

Amygdala: This structure, which is critical for the processing of and response to emotions such as fear, anger, and attraction, is also located deep inside the temporal lobe right in front of the hippocampus.

Striatum: This area, which is seen best from a cut down the middle of the brain, is involved in motor function and plays an important role in how we form habits (and why they are so hard to break!); it’s also integral to the reward system and how addictions develop.

Like the best teachers do, Diamond then made what initially seemed incomprehensibly complex totally understandable. She told us that this big complex mass of tissue was really made up of only two kinds of cells: neurons and glia. Neurons are the workhorses of the brain and each contains a cell body, which is the control center of the neuron; input structures called dendrites, which look like big tree branches, that receive information coming into the cell body; and a thin output structure called the axon, which can also have lots of branches.

What makes neurons unique from any other cell in the body is that they are able to communicate via brief bursts of electrical activity, called action potentials, or spikes. That cross talk between the axon of one neuron and the dendrite of the next one takes place at a special communication point between the two called a synapse. It’s the brain’s electrical “chatter,” or axon-to-dendrite communication, that is the basis for all the brain does.

Neurons and their connections.

(Courtesy of Ashley Halsey)

What about the glia cells? Glia means “glue,” and the cells were so named because scientists in the nineteenth century mistakenly thought these cells had something to do with holding the brain together. While it’s true that some of the glia cells do serve a scaffolding function in the brain, we now know that they actually serve a wide range of different support functions for neurons. Glia cells supply nutrients and oxygen to the neurons; they form a special coating on the neurons called myelin, which is required for normal synaptic transmission; and they attack germs and serve as the brain’s cleanup crew, removing the debris from dead neurons. Exciting new evidence suggests that glia cells may even be playing an important role in certain cognitive functions including memory. Many believe there are ten to fifty times more glia in the brain than neurons, but this often-repeated statistic is being challenged by new studies suggesting that the ratio is closer to one to one.

Diamond then explained that if we had a big bucket of neurons and another big bucket of glia, we, at least in theory, would be able to build a brain. But the big puzzle is figuring out exactly how we put those neurons and glia together to work as beautifully and elegantly—as perfectly and imperfectly, as correctly and incorrectly—as a real brain. I learned that day that figuring out those connections and the general question of how a brain is put together, otherwise known as the study of neuroanatomy, was Diamond’s specialty.

But what truly captivated the nascent scientist in me that first day of class was her description of brain plasticity. This does not mean your brain is made of plastic, but rather it refers to the idea that the brain has an essential ability to change (like a piece of malleable plastic) as a result of experience. And by change she meant the brain could grow new connections within itself. I still remember her giving us the analogy that if you study really hard your brain may ache because of all the axons and dendrites growing and straining to make new connections.

In fact, Diamond (as one of the very few women in science at the time) had been responsible for the now classic research starting in the early 1960s on exactly how plastic, or malleable, our brains really are. At that time, it was known that brains could change and grow extensively from infancy to adulthood, but it was believed that once we hit adulthood, our brains were set in stone, with no ability to grow or change.

Diamond and her colleagues at Berkeley challenged this notion in a very big way. In their now famous study, they asked what would happen to the brains of adult rats if you housed them in what she called “enriched environments.” This meant letting them live in a sort of Disney World for rodents, with lots of colorful toys to play with, lots of space to run around in, and lots of other rats to engage with. The researchers were looking to topple the idea that the adult human brain was fixed—that is, that it was not capable of change. In order to answer their question, Diamond and her team changed the physical environment that the rats lived in and asked whether there was any effect on the physical structure of the brain. If there was evidence of change in the rats, then that meant under certain conditions, human brains might also be able to grow, adapt, or change.

What were the results of housing rats in Disney World? Compared to rats living in what the researchers called impoverished environments, with no toys and only a few other rats to play with, the rats living in Disney World actually had brains that were physically larger than the impoverished rats. Diamond showed that in the enriched environment, dendritic branches (those input structures of the neurons that look like tree branches) actually grow and expand, allowing the cells to receive and process larger amounts of information. In fact, she showed that not only were there more dendritic branches but more synaptic connections, more blood vessels in the brain (that means better access to oxygen and nutrients), and higher levels of good brain chemicals like the neurotransmitter acetylcholine and particular growth factors.

Diamond explained that these differences in brain size were a direct reflection of the nature of the rats’ environments. In other words, the size and function of a brain—rat or human—is highly sensitive and reactive to all aspects of any given environment—physical, psychological, emotional, and cognitive. This constant interaction between the brain and the environment, combined with the brain’s ability to respond by changing its anatomical structure and physiology, is what neuroscientists mean by the term brain plasticity. Stimulate the brain with new things to do or new individuals to interact with and it reacts by creating new connections that cause it to actually expand in size. But deprive your brain of new stimulation or bore it with doing the same thing day after day after day, and the connections will wither away and your brain will actually shrink.

In other words, your brain is constantly responding to the way you interact with the world. The more diverse and complicated your interactions, the more neural connections your brain will make. The less enriched your environment and experience, the fewer neural connections your brain will make. There was nothing particularly special about the rats raised in Disney World; in fact all the rats in the study had the same capacity for reaction to stimuli. Do you play the piano? Then the part of your brain that represents the motor functions of your hands has changed relative to people who don’t play the piano. Do you paint? Play tennis? Bowl? All of these things we also know change your brain. We now understand that even the everyday things that we learn—the name of the guy that takes our order at Starbucks or the name of the newest movie we want to see—are all examples of the brain learning, which in turn causes the brain to make micro changes in its structure.

It was almost too much fascinating information to take in for the first day of class. But one thing was for sure. The first day of “The Brain and Its Potential” class changed my life. I walked in a curious enthusiastic freshman wanting to soak it all in, and I walked out a curious enthusiastic freshman with newfound purpose and meaning. I knew after that day in class what I wanted to do with my life. I wanted to study that lumpy mass of tissue and discover some of the secrets to understanding what it is to be human. I wanted to be a neuroscientist.

Over the next four years, I took many more classes with Diamond, including her wildly popular gross human anatomy class and her more advanced neuroanatomy class. You might not realize how much passion, enthusiasm, and clarity (plus a little magic) it takes to make an anatomy class really interesting. A course in gross human anatomy is a practice of committing to memory every single detail of your body—from your bones to your muscles (including the specific locations where bones attach) as well as every single internal organ and how each of them is hooked up to another. There are more than seventy-five hundred parts to the human body! As you can imagine, memorizing every single one is an enormous task. If a professor simply presented all this anatomical information in a flat, listlike way, the class would be akin to reading this year’s new income tax regulations—dry as dirt. But Diamond revealed the human body to us as if we were on a grand adventure in an exciting new universe, both familiar and strange. She also made everything personal, telling us that learning about the anatomy of our bodies was going to teach us about who we were as people. If we were going to keep our anatomy and our brain for the rest of our lives, wouldn’t it make sense to know what we were working with?

Diamond was a master at mixing information about the origin of an anatomical term or some lesser known anatomical fact with more basic lessons, therefore making every last piece of information seem relevant.

For example, she asked us:

The word uterus in Latin means “hysteria.” Do you agree with this?

Do you know what the largest organ in the body is? It’s your skin! Take care of it!

Isn’t the psychology of hair and hairstyles fascinating? We could have a whole course just on that!

With every comment and through every lecture, she made anatomy personal and come to life. I remember in the middle of the semester I took gross human anatomy, I happened to go see the Alvin Ailey dance troupe perform for the very first time at Zellerbach Hall on the Berkeley campus. That was the first time I saw their famous piece Revelations. Not only was I mesmerized by the dancing that night but, because we had just been going over the origins and insertions of all the muscles of the leg, I could now appreciate all those movements on a whole different anatomical level. To me there was no better example of the beauty of the human body than the shapes and movements that I was seeing on stage.

Diamond was truly an inspiration. It was so clear she loved and appreciated the topics she was teaching, and she genuinely wanted us to love and appreciate this breadth of information in the same way. She didn’t only care about the subject matter but cared deeply for us students as well. She was more than available to answer questions, and just to be sure she got to know at least some of us in her class of at least 150 students, she would randomly pick names of those enrolled out of a hat and take two of them out to lunch just to chat over a meal. When I was taking her class all her students also had an open invitation to come out to the tennis courts on the north side of campus to play an early morning set of doubles with her anytime. This sounds like the perfect invitation for the tennis-playing neuroscience geek from Sunnyvale, right? Well, I have to admit that I let my shyness get the better of me, and I never gathered the courage to go play tennis with her in all the years I went to Berkeley—to this day it’s one of the biggest regrets on my list of should-haves from my college years.

Some of her teaching magic started to rub off on me, even back then. I remember an afternoon practical session where we had a whole bunch of organs spread out at different stations in the room that we were supposed to examine and learn about. I was particularly intrigued with the dense, multilobed liver and the little nub of a bile duct hanging off the bottom. I remember figuring out all the parts of the liver we had learned in class and another student coming by and asking me what we were supposed to be seeing here. I explained to him everything that I had discovered on this example liver, and he seemed to get it quickly. I ended up spending the next thirty minutes presiding over that liver and explaining to any and all students that came by all the key features of the organ. That day I became a liver anatomy expert. I think that was the day I also became a teacher. And I learned a valuable lesson that was going to serve me well for the rest of a career: The best way to learn something deeply is to teach others about it. I use that principle to this day.

The author with Dr. Marian Diamond on the day Suzuki graduated from Berkeley.

(Courtesy of the author)

I was certainly not the only one to love Diamond’s gross human anatomy class. On the last day of class, several other students came to class with flowers and literally threw them at her feet! I was there cheering and shouting right along with them, celebrating the end of this great course, my only regret being that I hadn’t thought to bring flowers to throw.

CHECK OUT MY ROCK-STAR PROFESSOR!

The great thing about our digital age is that you now can experience some of Diamond’s classes yourself. Just search for “Marian Diamond” on YouTube. Check her out!

WHAT WE KNOW ABOUT THE BRAINS OF CAB DRIVERS

We have come a long way in our understanding of brain plasticity since Marian Diamond’s early enriched environment studies in rodents. Now there is lots of evidence of brain plasticity, including in humans. One of my very favorite examples of adult human brain plasticity was done by my colleague Eleanor Maguire, at University College London. Maguire didn’t send her human subjects to live in Disney World for a year. Instead she studied a group of people who had meticulously learned a very specific and extensive body of knowledge about their home turf. Namely, she studied London taxicab drivers. You see, London cabbies have the daunting task of learning to navigate the more than twenty-five thousand streets in central London as well as the locations of thousands of landmarks and other places of interest. The extensive training period that is required to learn all this spatial information is called “Acquiring the Knowledge” and typically takes between three and four years of study. If you have ever been to London and seen people riding around on scooters with maps splayed out on the handle bars, those are the aspiring London taxicab drivers learning these skills!

Only a fraction of the aspiring cab drivers actually pass the stringent exams, called, very dauntingly, “Appearances,” but those who do pass demonstrate an impressive and extensive spatial and navigational knowledge of London. What an interesting group of people (and brains) to study!

In the study of these London cab drivers, Maguire’s group focused on the size of a brain structure that I will be discussing a lot in the upcoming chapters: the hippocampus. This is a long seahorse-shaped structure deep in the brain’s temporal lobe (hippocampus means “seahorse” in Latin) critically involved in long-term memory function, including spatial learning and memory. More specifically, because Maguire and her colleagues had localized spatial memory function to the back, or posterior, part of the hippocampus, they wondered if that part of the brain structure might be larger than the anterior (front) part in cab drivers when compared to control subjects who were matched for age and education. In fact, that’s exactly what they found.

Maguire’s research and other studies that have compared the brains of experts (such as musicians, dancers, and people of particular political affiliations) to nonexperts have all been used as examples of brain plasticity in humans. While plasticity is one possible interpretation of the data, another possibility is that people who succeed as London taxicab drivers have larger posterior hippocampi to start with. In other words, it could be that only people with naturally big posterior hippocampi have the superior spatial navigation ability required to succeed as a London cabbie. If this were true, it would not be a case of brain plasticity at all.

So, how can we differentiate between these possibilities? What would need to happen to test the idea that the experience of learning to be a London taxicab driver changes the brain would be to actually follow a group of people who started Acquiring the Knowledge and then compare the brains of those who eventually passed the test with those who did not. And that’s exactly what Maguire and her team did. This kind of study is much more powerful because you can clearly identify any brain changes as a function of taxicab training. What the researchers found is that before training started, all the wide-eyed and bushy-tailed London taxicab driver wannabes had the same size hippocampi. The scientists then reexamined the cab drivers after they had completed the training period and after they knew who passed and who failed. They found that the wannabe cabbies who passed now had significantly larger posterior hippocampi than they did before they started their training. Ta-da! Brain plasticity in the flesh! This group’s posterior hippocampi were also larger than those of the subjects who hadn’t passed. In other words, this experiment showed that successful training to pass the Appearances exam did indeed enlarge the hippocampus, and the trainees who had not retained enough information showed far less of an increase in size.

This is just one example of the everyday, beautiful plasticity of our brains. Everything we do and for how long and intensely we do it affects our brains. Become an expert bird watcher, and your brain’s visual system changes to be able to recognize all those tiny little birds. Dance tango all the time, and your motor system shifts to accommodate all those precise kicks and flicks you are doing with your feet. The life lesson I learned all those years ago in Diamond’s classroom was that I shape my brain every day and so do you.

MY OWN DOORMAN EXPERIMENT

London is not the only city where its municipal workers have special skills. In New York, it’s doormen. Think about all those faces they have to recognize and differentiate from strangers if they work in a thirty- or forty-story high-rise! Here is a thought experiment I would love to do with New York City doormen if the opportunity ever arose. I would examine the doormen’s brain areas known to be important for face recognition and compare the size of that area to those of other city workers who don’t have to remember lots of faces (let’s say subway conductors). Where exactly is the face recognition area in the brain? At the bottom of the temporal lobe is a unique area known as the fusiform face area, which specializes in helping us recognize faces. When this region is damaged, people cannot distinguish facial features, a condition known as prosopagnosia. The actor Brad Pitt, the famous portrait painter and photographer Chuck Close, and the Harvard professor and author of Multiple Intelligences Howard Gardner are a few famous people with prosopagnosia. Because they cannot recognize people by their faces, they rely on other features such as voice, hair, gait, and clothing. But in doormen, who develop and hone the skill of quickly recognizing sometimes hundreds of faces, I predict that this fusiform area will be significantly larger than that in the subway conductors. Maybe someday I’ll get to do this experiment.

MY OWN PERSONAL ENRICHED ENVIRONMENT: ADVENTURES IN BORDEAUX

My life in college was firmly focused on doing well in my classes, though I did date a couple of guys (somewhat awkwardly) during my first two years at Berkeley. Despite my general shyness as a young woman, the truth is that I have always had an adventurous spirit and I was itching to see the world and travel abroad. U.C. Berkley had the perfect study abroad program for me, and I signed up in my junior year. I learned that if I went to particular campuses abroad, I could even take science classes that counted toward my major of physiology and anatomy, so I would not lose any credits. The only country I would even consider visiting was France. I had been enchanted with the French language ever since I started learning it in junior high. My choices for campuses were either Bordeaux or Marseille. In other words, wine or fish soup. The choice was clear—I went for the wine! Little did I know when I signed up for my junior year abroad adventure that France, with its unique culture, beautiful language, strong traditions, glorious foods and wines, stylish clothes, amazing museums, excellent educational system, and brilliant residents (especially the men) was going to serve as my own personal enriched environment for the next twelve months.

IS THERE A CRITICAL PERIOD FOR LEARNING A LANGUAGE?

Everyone agrees that there is a very special time, called the critical period, during about the first six months of life when the brain is particularly good at learning languages. Wonderful work from Professor Patricia Kuhl at the University of Washington has shown that babies’ brains can soak up and learn not just one language but multiple languages during this time.

But what if you start learning a new language a little later in life? Like most people of my generation, I began learning a second language (in my case French) at the ripe old age of twelve when I got to middle school. What part of my brain helped me learn this second language? It turns out that the brain does rely on many of the same areas as are used when learning to speak your native tongue. However, you also seem to recruit additional brain areas to help you with a second late-learned language. These additional areas are situated toward the bottom part of the frontal lobe on the left side, called the inferior frontal gyrus. You also use the left parietal lobe. Another study showed that people (like me) who learned language later in life actually had a thicker cortex in the left interior frontal gyrus and a thinner cortex in the right inferior frontal gyrus.

Learning a second language at twelve years or later provides yet another example of brain plasticity. The brain, when prodded to make connections, will indeed do so. It might take longer and be more difficult, but it’s possible!

I loved the year I spent in France because it completely immersed me in a totally foreign and exotic culture that in 1985 was far less infiltrated by American cultural icons like McDonald’s, Costco, and reruns of Friends than you see in France today. That year abroad also brought me one of the most romantic experiences of my life.

It all started with my request to live with a family in Bordeaux who had a piano that I could play. I had played the piano from the time I was about seven until I was a senior in high school, and I still played casually (so as not to completely lose my classical repertoire) while I was studying at Berkeley.

Monsieur and Madame Beauville were a lovely couple whose home had a few extra bedrooms upstairs, one of which housed a piano. Soon after I arrived, Madame Beauville asked me to make sure I was at home one particular afternoon at a particular time because she had hired a piano tuner to come. I happily agreed and waited for the little old man with white hair to come walking up the stairs to my bedroom to tune the piano. But to my surprise, it was not grand-père who made his way up the stairs to my bedroom, but a young, hot French guy named François. François set about tuning my piano and chatting with me in French, of course. Before that day I never thought I was particularly good at flirting. But that day I discovered I was good at it, and I could even do it in French! In that hour, I not only got a perfectly tuned piano for my bedroom but I snagged a card with the address of a sheet music shop where François worked part time and an invitation to come by and say bonjour anytime.

Of course, I somehow found time in my busy schedule of lectures, coffee, and croissants to visit him in the music shop right around dinnertime, and he invited me for a bite to eat. After just a few more dates that began after his shift in the music shop, we were an item, and I suddenly had myself a very sweet and musically inclined French boyfriend.

How had I come out so far out of my shell? I had no idea, but I see now the enormous amount of brain plasticity occurring that year. This was even better than living in Disney World. Everything was so different—not only was I speaking French all the time and taking all of my classes in French but I truly felt like a different person while speaking the language. Suddenly, I was no longer the geeky wallflower with nary a date in sight. Instead, in France I was considered extremely exotic because I was an Asian woman from California who didn’t speak Japanese but instead spoke fluent American. When I was growing up in northern California, Asian American women were a dime a dozen; now I got to be exotic for the very first time in my life. That was huge for me. Not only that, but—I don’t know if you are aware—the French kiss each other all the time. It’s a rule. You have to kiss; it’s frowned upon if you don’t. Finally! An excuse to kiss everyone for the girl from the family that didn’t hug or kiss much at all—I was in seventh heaven.

And the more I learned, the happier I became.

In France, all this kissing made me step out of my comfort zone and become a lot looser and a lot more affectionate. I now realize that making these kinds of changes literally expanded who I was: As I changed my behaviors and experienced new sensations, my brain made adjustments to this new information and stimuli.

Aside from François, my French became fluent because I was also taking some serious science classes—not with American students mind you, but with all the other French students. That meant all the lectures were in French and, most terrifying for me, the oral and written exams were all in French. I was not that worried about the written exams because most of the science words are the same as or similar to the English words. But I had never in my academic career taken an oral exam. Much less in my second language. I was totally scared.

One of my clearest memories from this time was while I was responding to the questions a professor posed during an oral exam. I was very nervous and suddenly lost all ability to speak with a proper French accent. The words and the grammar coming out of my mouth were all French, but the sounds were pure American. I could hear myself speaking French with an incredibly strong American accent—quelle horreur! Good thing I was graded on content and not verbal presentation. I ended up acing all my classes. Clearly the geeky bookworm was still present somewhere in my new French incarnation.

This experience in France also gave me another unexpected and what turned out to be lifelong gift. It was in France that I became fascinated with the study of memory, another form of brain plasticity. I had the great good luck to take a course at the University of Bordeaux called “La Neuropsychology de la Memoire” (neuropsychology of memory). This course was taught by a very well-respected neuroscientist, Robert Jaffard, who not only ran an active research lab but was a wonderfully clear and engaging lecturer. I had no idea there was a strong neuroscience group at the University of Bordeaux when I chose it, but what a lucky coincidence. Jaffard was the first to teach me about the history of the study of memory and the raging debates of the day involving two researchers at the University of California, San Diego, named Stuart Zola-Morgan and Larry Squire and one researcher at the National Institutes of Health (NIH) named Mort Mishkin. Little did I know at the time that in the next ten years I would work with all three of these scientists either as a graduate student at U.C. San Diego or as a post-doc at NIH. Most important, Jaffard took student volunteers in his lab, and I happily began testing little black mice on memory tasks in my spare time, giving me my very first real taste of laboratory research. I loved it in the lab, and this, along with the wonderful background in neuroanatomy I had from Diamond (I also worked my entire last year at Berkeley in Diamond’s lab), made it easy for me to decide that I wanted to apply to graduate school as soon as I finished my undergraduate degree.

In between studying for classes and working in the lab, there was François. It turns out that he not only tuned pianos but played the piano and had a near obsessive fascination with the harmonies of the Beach Boys. So I had found a French guy with California in his heart. He had tapes of all the Beach Boys albums and I would often find him in his living room listening intently to them through his headphones as he tried to painstakingly transcribe all the complex chords they used to create their sound. He was doing this with such glee and concentration that I hated to interrupt his sessions. I too was a big Beach Boys fan, but I had never fully appreciated the complexities of their harmonies before François. I thought the Beach Boys were just fun and easy to dance to, but François, with his trained musical ear showed me his favorite chords and riffs in that music I knew so well, and opened it up in a very different way for me.

One of the many things we enjoyed doing together was playing piano duets. At first, François had only one piano in his apartment, but because he worked at the biggest piano store in town, he eventually borrowed a second piano so that we could practice and play our duets in his apartment, where I was spending increasing amounts of my time. And because I loved playing classical music, we played classical duets—Bach, to be precise.

But the really fun part was when we went to the piano shop at night after it had closed. There in the empty store we performed our duets on the big beautiful eight-foot concert grand pianos that were used for performances in the local theaters. I always played the Bösendorfer (I loved the sound of those low notes), and he played the Steinway. We played as loud and long as we wanted, and the beautiful tones of these pianos (expertly tuned by François himself) made even the mistakes sound good. I consider these evenings as some of the loveliest times I spent with François.

In addition to playing classical music together, we listened to a lot of it. One of my favorites was the Bach solo cello suites. I listened to François’s record of Yo-Yo Ma playing these pieces over and over again. It turns out that François noticed how much I loved them, and that Christmas I received the most precious gift that I had ever received before or since: a cello.

I was flabbergasted.

For someone who had dated only a little bit in her first two years of college, I was getting a crash course on romance from François that I didn’t want to end. I decided that the myth was absolutely true: The French are the most romantic people in the world!

THIS IS YOUR BRAIN ON MUSIC!

Do you ever wonder what happens in your brain when you hear that piece of music you can listen to over and over and over again? The one that may even give you chills just listening? Robert Zatorre and his colleagues at the Montreal Neurological Institute showed that when people listened to music that gave them a strong emotional and physiological response (the Beach Boys for François, and Bach for me), the brain showed significant changes in the areas involved in reward, motivation, emotion, and arousal: the amygdala, orbitofrontal cortex (the bottom part of the prefrontal cortex), ventral medial prefrontal cortex, ventral striatum, and midbrain were all activated. So as François and I delved into playing and listening to music together, we were also activating the reward and motivation centers in our brains (see Chapter 8). No wonder I loved France so much!

So my French-enriched environment gave me a new language, a new persona, romance, adventure, and—of course, I have to add to the list—great food and wine. It was during this time and with François that I also really developed my love of French cuisine. My parents, and in fact my whole family, are great lovers of food and any big celebration—whether it be a graduation or a recital—has always been celebrated at a wonderful restaurant. But in France, my food experiences stepped up to a whole new, more sophisticated level. While I was a poor college student, you could still eat (and drink) like a king in Bordeaux, especially if you had a native son like François as a guide. Yes, I worked and studied like the science geek that I was, but I ate, drank, and spent leisure time playing the piano like a sexy flirtatious exotic French woman in love. Look at me! The world-class wallflower from Sunnyvale had a fantastic French boyfriend and a rich social, food, and cultural life. It was easy to do in such an enriching, stimulating environment.

FOOD, WINE, AND BUILDING NEW BRAIN CELLS

Living in France, it was not hard to eat a lot of delicious, flavorful French food and drink many delectable bottles of wine. Indeed, I tasted, sipped, and enjoyed wines of all kinds from all over France—from Burgundy, the Loire Valley, Provence, and Bordeaux. White, red, rose, and of course Champagne. All of these new tastes were literally turning on my brain. It turns out that experiments in rodents have shown that enriching your olfactory/gustatory environment does have a significant effect on the brain.

Studies show that once we grow into adulthood, there are only two brain areas where neurogenesis (the birth of new neurons) can occur. The first brain area is the hippocampus, which is crucial for long-term memory and mood (more on these two features in upcoming chapters) and the second is the olfactory bulb, the brain area that is responsible for our sense of smell and therefore also contributes to our sense of taste. Studies show that if you enrich the olfactory environment of rats by giving them a nice big range of smells, you can enhance neurogenesis in the olfactory bulb and that the brain actually increases in size because of these new neurons. This suggests that my French adventure was not only teaching me a lot of about food and wine appreciation, but might actually have been enhancing the size of my olfactory bulb. While changes in size of the olfactory bulb in people with enhanced olfactory experiences have never been explicitly studied, it would be fascinating to examine this potential form of human brain plasticity. I feel a new brain plasticity experiment with sommeliers coming on!

In short, I loved France. I loved my life with François. But as the year passed by I knew that soon I would have to face the reality that I was due back at U.C. Berkeley to start my critical senior year and begin the next phase of my life. This was a difficult time for me because from a very early age I have always had a hard time letting go. I was the kid who worked herself into a tizzy and cried at the end of the summer because I didn’t want it to end and to go back to school. And I loved school. I just didn’t like endings. I think it was the fear that if something wonderful like summer vacation ended, I would never get it back. I don’t know where this fear came from—maybe I had a toy taken away from me as a child—I can’t say for sure. But what I do know is that I had that terrible feeling of impending sadness in the spring of 1986 when my year in France was coming to an end.

In fact, I seriously thought about staying in France to finish my college career and do graduate work there. That would work, right? I was already working in a lab. A wise French scientist working in the Jaffard lab, to whom I will always be grateful, convinced me that I would be much better off going to an excellent graduate program in the United States. He was right, but that was not the answer I wanted to hear. My parents, who were none too happy about my involvement with a piano tuner/musician with no degree or higher education of any kind, wanted me back home and attending classes at U.C. Berkeley immediately.

But I didn’t want this magical year or my relationship with François to come to an end. How could I? Give up being the exotic English-speaking Asian girl with the hot French boyfriend for my old single life of science geekdom in the States? What could be worse?

I knew I was at a crucial point in my life. I knew that yes, I did have to return. There was no real possibility of staying in France after my year was up. I knew deep down that I not only had to finish my degree at Berkeley but I really wanted to finish my degree at Berkeley. But François could come with me, right? We could be together in the United States, and then we would decide what came next. Both of us held on to that dream for several months after I returned to school in California and started taking classes again. We were like a French and Japanese American version of Romeo and Juliet, with my parents playing the part of the disapproving family perfectly. Actually, my parents had enough disapproval between them to play the roles of both the Capulets and the Montagues. Every day, I wrote François long letters in French, telling him about everything that was so different in the States and all the things I missed about living in Bordeaux. We both wanted to keep our relationship alive, me with the hot French musician and he with the exotic Asian American girl who loved science.

That dream lasted for several months, until one day reality knocked on my door and walked right in. Specifically, the reality of applying and attending graduate school arrived. I suddenly realized that it was unlikely that François could make a living tuning pianos in the United States, especially since he didn’t speak English. And most difficult for me to admit, I knew deep down that while I so enjoyed going out with him for the year that we were together, he was probably not the lifelong partner for me. Besides, what did I know at the ripe old age of twenty-one? He was the first serious boyfriend I had ever had.

To this day, my last phone conversation with François is etched in my memory with great detail. I remember where I was sitting in my little studio apartment in Berkeley; I remember how I was sitting and holding the phone. Mostly I remember the pain, guilt, and discomfort I felt during that conversation, as if it happened yesterday. I did a terrible job breaking up with him and I knew it, but at that time I didn’t know any other way. I should have been more loving and understanding, and I should have explained the situation and my logic more clearly. Instead I felt pressured to get on with my life, and I was rude and abrupt with him. I know why I remember that call in so much detail. Emotion, either very negative, like the one that I was experiencing that day, or very positive, helps strengthen memories. One brain structure in particular, called the amygdala, which sits in the temporal lobe just in front of the hippocampus, is critical in the formation of strong memories from strong emotions. My amygdala was working overtime that day (you’ll learn much more about why we remember emotional events in the next chapter).

That day, I chose science over François. It was a hard decision, and it took me months to recover. But I know now that it was a choice that shaped the rest of my life.

THE STAR OF OUR EVOLUTIONARY BRAIN

The prefrontal cortex (PFC), situated just behind the forehead, was the last part of the brain to evolve, and scientists agree that it sets humans apart from most other animals. The PFC is essential for some of our highest-order cognitive abilities, including working memory (defined as the memory we use to keep things in mind, also referred to scratchpad memory), decision making and planning, and flexible thinking. In essence, this is command central for all of our executive functions, which play a role in so much of what we do and how we think. You will see how the PFC has a role in applying new concepts to other learning situations, managing our stress response, and supervising our reward system. Keep an eye out for the powerful PFC!

TAKE-AWAYS: BRAIN PLASTICITY

✵ The brain is made up of only two kinds of cells: neurons (brain cells) and glia (supporting cells).

✵ Brain plasticity is the ability of the brain to change in response to the environment. Raising rats in enriched environments results in a thicker cortex, more blood vessels, and higher levels of certain neurotransmitters and growth factors.

✵ Training as a London taxicab driver results in brain plasticity. Cab driver recruits who studied and passed the difficult qualifying examination had larger posterior hippocampi, a structure known to be involved in spatial memory, than those who did not pass the exam.

✵ Areas of the brain recruited when you lean a second language include the inferior frontal gyrus on the left side and parts of the parietal lobe on the left side. Language in general is controlled by the left side of the brain.

✵ Music activates the parts of the brain involved in reward, motivation, emotion, and arousal, which include the amygdala, orbitofrontal cortex, ventral medial prefrontal cortex, ventral striatum, and midbrain.

✵ The prefrontal cortex is the command center of the evolved human brain and supervises all executive functions.

✵ Enriching your olfactory environment with lots of different smells stimulates the growth of new brain cells in the olfactory bulb, a key part of the brain responsible for our sense of smell.

BRAIN HACKS: HOW DO I ENRICH MY BRAIN?

You may not have time to go live in Disney World or France for the next few months, but the great news is that you can start to enrich your brain with these Brain Hacks, most of which take no more than four minutes per day.

Motor cortex Brain Hack: Go online and teach yourself a new dance move from the So You Think You Can Dance website and then practice it for four minutes to your favorite music.

Taste cortex Brain Hack: Try a cuisine that you have never tried before: Laotian, African, Croatian, and Turkish come to mind. Be adventurous! And here is another taste cortex Brain Hack for extra credit: Try eating a meal in complete darkness and see how the lack of visual input affects your sense of taste. It should change your experience of the meal and allow a pure taste sensation to come through.

Cognitive Brain Hack: There are so many fun possibilities to enrich your brain. Here are just a few: Watch a TED talk on a topic you know nothing about. Listen to a story from the Moth Radio Hour, a storytelling program with a wide range of topics. Listen to a popular podcast that you have never listened to before. Read a story from the section of the newspaper that you never read—for me it would be finance or sports.

Visual cortex Brain Hack: The next time you go to a museum, pick a piece of artwork that you are not familiar with and just sit quietly and get lost visually in it for at least four minutes. In reality, it could take hours to really explore a new piece fully; you can get a great start, though, in just four minutes. A hack for this hack is to simply find a new piece of art online and explore it visually on your computer. Both will stimulate your visual cortex.

Auditory cortex Brain Hack: Go to iTunes, the YouTube music channel, Pandora, Spotify, or whatever music site you like and listen to a really popular song from a genre of music you never listen to or in a different language. Try to understand why it might be number one for that genre.

Olfactory Brain Hack: The main difference between regular sommeliers (who can differentiate many different scents and describe them so precisely) and you or me is one thing: practice. Take just a few minutes to sit and smell your most odorous meal of the day. It might be breakfast with a rich, aromatic cup of coffee and the deep comforting smell of toast fresh from the toaster, or it might be your dinner of chicken tikka masala from your favorite Indian restaurant. Before digging in, take a few minutes to smell the food and try to really notice the different aromas and try to describe them. This will start to tune you in more to your olfactory senses.