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November 1, 1998

The Brains Behind the Brain

Five authors of recent books on brain research apply current thinking to the classroom.

While developing the ASCD video-based professional development program "The Brain and Learning," Marcia D'Arcangelo interviewed five prominent educators and researchers noted for their commentary on brain research.

Marian Diamond is a neuroscientist and professor of neuroanatomy at the University of California at Berkeley. Her research with rats documented the influence of the environment on the growth of brain cells.

Pat Wolfe, an educational consultant, has studied brain research over the past decade, drawing implications for classroom practice.

Robert Sylwester, professor emeritus of education at the University of Oregon at Eugene, has authored numerous articles and books about the brain and learning.

Educator Geoffrey Caine, with Renate Nummela Caine, has written several books interpreting brain research and its influence on education reform.

Eric Jensen's work with underachieving students led to his interest in brain research. His 11 books and professional development programs offer suggestions for everyday practice.

Marian Diamond, you've studied the anatomy and physiology of the brain for more than 40 years. You've said that we need to know everything about the brain before we know anything. If this is the case, how can teachers with their busy schedules learn about this vast topic?

Marian Diamond: If I had to teach educators what they need to know most about the brain, I would teach about the cerebral cortex. That's where higher cognitive processing occurs. The cerebral cortex doesn't work by itself, but when we educate students, we're essentially changing those neurons, or nerve cells, their structure, and their chemistry in students' cerebral cortices.

Brain Fact: Basic Anatomy

The adult human brain weighs about three pounds. It is made up chiefly of water (78 percent), fat (10 percent), and protein (8 percent).

The brain is about 2 percent of an adult's body weight, but it consumes about 20 percent of the body's energy.

Our brains contain about 100 billion nerve cells, or neurons, and 1 trillion supporting cells, the glia. Together, the nerve cells of the brain make 1,000 trillion synaptic connect points with each other.

The brain is made up of four areas, called lobes. The occipital lobe, located in the middle back of the brain, is primarily responsible for vision.

The frontal lobe, the area around the forehead, is involved in purposeful acts like judgment, creativity, problem solving, and planning.

The parietal lobe is in the top back area of the brain. Its duties include higher sensory and language functions.

And the temporal lobes, on the left and right sides of the brain, are primarily responsible for hearing, memory, meaning, and language. There are some overlaps in the functions of the various lobes.

Sources: Jensen, E. (1998). Teaching with the brain in mind (p. 8). Alexandria, VA: ASCD.

Diamond, M., & Hopson, J. (1998). Magic trees of the mind: How to nurture your child's intelligence, creativity, and healthy emotions from birth through adolescence (p. 37). New York: Dutton.

Much of your research focuses on how the brain changes physically in response to the environment. You work with animals because of the similar structure and behavior of nerve cells across species. What have you found that applies to humans?

Diamond: We work with rats because I have yet to find a human being who's willing to give me a piece of cerebral cortex to study. We investigate the changes in the structure of the nerve cell in the cerebral cortex when rats are exposed to either an enriched or an impoverished environment.

We found that the rats living in the enriched environment had developed a thicker cortex than those rats living in the impoverished environment. Their cortex had grown as a result of interacting with other rats and with objects to explore and climb upon.

As the nerve cell gets stimulated by new experiences and by exposure to incoming information from the senses, it grows branches called dendrites. Dendrites are the major receptive surface of the nerve cell. One nerve cell can receive input from as many as 20,000 other nerve cells. And if you have 100 billion cells in your brain, think of the complexity! With use, you grow branches; with impoverishment, you lose them. This ability to change the structure and chemistry in response to the environment is what we call plasticity.

So, the rat that can socialize with other rats and play with different toys grows a greater number of connections among nerve cells. Does this increase in connections have anything to do with intelligence? And what might that imply for the classroom?

Diamond: Intelligence depends on the connections among the nerve cells. The rats that live in the enriched environment can run different kinds of mazes with greater ease than rats that live in the impoverished environment. The rats that sit and watch other rats in the enriched environment have fewer measurable changes than the rats that actually participate.

No two human brains are alike. An enriched environment for one is not necessarily enriched for another. No two children learn in the identical way. In the classroom, we should teach children how to think for themselves. One way is to group children so they're talking to one another, they're asking questions of each other, they're learning to be teachers. One of the most important concepts for a 5-year-old to know is that he or she can teach because you have to understand something to teach it.

Pat Wolfe, in recent years, you've studied the works of Marian Diamond and others to build a bridge between education and neuroscience. First, what should educators know about the physical structure of the brain?

Pat Wolfe: Basically, the brain is an oblong organ that weighs about three pounds. It has an obvious fissure down the center that separates it into two hemispheres. Its covering, a wrinkled, one-quarter-inch-thick blanket of cells, is called the cerebral cortex, and it is divided into lobes, each of which performs many different functions. In the back of the brain, the occipital lobes process visual stimuli. On the sides near the ears, the temporal lobes process auditory stimuli. Up a little higher and toward the back of the brain are the parietal lobes where interpretation and integration of sensory stimuli occur. Just behind your forehead are the frontal lobes where higher-level thinking, problem solving, and planning for the future occur. Somewhere in this entire cerebral cortex lies your ability to be consciously aware of what you're thinking and doing. Researchers don't yet know what consciousness is; it's a current focus of memory research.

Deep under the cortex are structures such as the amygdala, the hippocampus, and the thalamus. These and others are involved in processing emotion and memory. Because the cells in these structures evolved long before the cortex, they are thought to be less plastic and changeable than the cortex cells.

The most basic unit in the body is a cell. The brain has two different kinds of cells: nerve cells, or neurons, and glial cells. Glial cells greatly outnumber neurons and provide the scaffolding during development and the structure, and they assist in providing the nutrients for the neuron. As far as we know, neurons are the only cells that process information. With a few exceptions, you can't grow new neurons, but you can grow new connections between neurons, and these connections create learning and memory.

How do nerve cells talk to one another?

Wolfe: Each nerve cell acts like a relay station, receiving signals from other cells, processing the signals, and sending them on to other cells across tiny gaps called synapses. Nerve cells don't actually touch. They produce chemicals called neurotransmitters—neuro meaning mind, transmit meaning send. The neurotransmitter is produced in the cell body terminals and stored in little sacks down in the axon terminals. When a neuron fires, an electrical impulse moves down the axon and stimulates those little sacks of chemicals to move to the surface, break open, and spew their contents out into the gap between the axon terminal and the dendrite of a neighboring cell. The dendrites have little receptor sites, welcome sites, designed specifically for a particular neurotransmitter. It could be serotonin, dopamine, or any of 60 to 100 neurotransmitters and neuromodulators that the brain produces. The chemicals fit into the receptor sites kind of like a lock and key. This causes a new reaction in the receiving dendrite, which then sends a message down that cell's axon and starts the whole process over again. At that point, the brain takes the neurotransmitter back up through re-uptake channels in the sending neuron and uses it over again. The brain knows how much chemical to make, what kind of a chemical to make, how much to let out, how long to leave it there, and what to do when it's through.

This electrochemical process is the basis of all human behavior. Every thought we think, every move we make, and every word we say is based in the electrical and chemical communication between neurons.

How do we take this information and use it in the classroom?

Wolfe: Our challenge in education is to determine what makes an enriched classroom environment. We're probably going to find that it's the interaction of the student's mind with the materials, the simulations—all the things that good teachers have always done to make learning meaningful so that students sprout new dendrites, which form new connections and become strong through review. The second time two neurons fire together, they become more efficient and fire more readily. That develops what we call long-term memory.

Diamond: The important thing that we've learned is that repetition helps memory. Teachers should know that it's all right to say something once and then turn it around and say the same thing in another way, to use repetition.

Memorization has fallen out of favor as a pedagogical approach in recent years, and you seem to be saying that it has a place in teaching.

Diamond: Oh, I'm very much in favor of a certain amount of rote memory, especially for learning vocabulary, to accompany word problems and decision making.

We often hear about "windows of opportunity" that slam shut if we don't stimulate the neurons appropriately when the brain is ready to learn. How critical is this, and is this idea not contrary to the notion of plasticity?

Diamond: Human beings get an explosive growth of dendrites in their first 8 to 10 years. But after that, the branches that haven't made connections die off. We call this process pruning. The cortex grows rapidly, reaches a peak, and then slowly decreases. If you put an animal in an enriched environment when the cortex is starting to go down, it will pick up. If the animal is left in an impoverished environment, the cortex will continue to decrease. That's why there's so much interest today in those first 10 years of life. But I do worry when people say things like "Well, if you don't do something by 3 years of age, forget it, you've closed that opportunity to stimulate that brain." We don't want to give the impression that all of cortical input is essential that soon, though it is true for certain functions to reach optimal development, such as vision, hearing, and beginning language.

Robert Sylwester: The best time to master a skill associated with a system is just when a new system is coming on line in your brain. Language is a good example. It's very easy for a 2- or 3-year-old to learn any language. But if that person waits until 18 or 30, learning a new language will be more difficult because the systems governing this have been used for something else. Many skills, like learning to play a musical instrument or developing fine and gross motor skills, are best done as early as possible. Fortunately, we humans live such a long time that we have long windows of opportunity. It's possible to learn how to play a musical instrument quite late in life.

Is the message that the brain's capacity for learning and change is limitless, depending on our willingness to seek new experiences and opportunities?

Diamond: Exactly! The most exciting discovery about all this work is that education should continue for a lifetime. With enrichment, we grow those dendrites; with impoverishment, we lose them at any age.

Geoffrey Caine, you and Renate have written about how understanding brain functions helps us create better learning experiences for students. Is it not also true that educators could profit personally and professionally by having a broader understanding of what makes us who we are and how we can interact more effectively with others?

Geoffrey Caine: Absolutely. There are some principles that drive learning. Every human being is driven to search for meaning. We all try to create patterns from our environment, and we all learn to some extent through interaction with others. Because ours is a social brain, it's important to build authentic relationships in the classroom and beyond. Complex learning is enhanced by challenge and inhibited by threat. We want to deeply engage learners with their purposes, values, and interests. Thinking and feeling are connected because our patterning is emotional. That means that we need to help learners create a felt meaning, a sense of relationship with a subject, in addition to an intellectual understanding. Once educators and parents grasp that complexity, they begin to function differently in their lives and in their classrooms.

To change behavior that has been somewhat successful may seem risky for teachers.

Sylwester: John Dewey said that the most mature person in any social setting is the one who's the most adaptable to other people's needs. In many classrooms, 30 students are adapting to the teacher rather than the teacher adapting to them. A mature person ought to be able to go with the flow of a classroom.

Changing teaching practice and going with the flow of the classroom are exciting concepts, but are they easier said than done?

Caine: Yes, it's a challenge. Learning isn't necessarily sequential. For the last 100 years or more, teachers have been in control of the content of learning. You have a textbook, a lesson plan, and a prescribed curriculum. Good teachers have become adept at teaching the prescribed curriculum. With the rapid spread of information technology, media in the classrooms, and increased interaction between parents and schools, the walls of schools are breaking down. This means that teachers are no longer as in control of information as they have been. As there is less and less time to teach more and more, teachers are going to have to function differently. That's going to involve a dramatic change in education.

That term change strikes fear in the hearts of some and skepticism in the minds of others. What specifically do you suggest, on the basis of your brain research?

Caine: Renate and I suggest several different instructional approaches. One is the old stand-and-deliver model. Instructional approach number two is where most educational reform is heading: The teacher is still in charge but creates richer and more complex experiences for students. Instructional approach three is different. It's a very messy, complex, interactive environment where teachers and students tend to be in partnership. In this approach, the teacher has to learn how to elicit and then to facilitate learning based on student interest. Education has to move in that direction to prepare children for an increasingly complex world.

Is there not value in all three approaches?

Caine: We're not trying to separate them. Each approach incorporates the others. We will always have some need to present material in segmented chunks of time on specific topics, where we want students to be quiet. Teachers will always have some need to construct activities or experiences and then to facilitate what students do. And beyond that, we need this rich environment where students begin to take charge but are supported by the teacher.

How do teachers decide which approach is most appropriate in any given circumstance?

Caine: Any decision that teachers make about what to do in the classroom must reflect their mental model of what learning and teaching are all about. If teachers think that every subject is naturally fragmented, that economics, math, geography, and history are separate, then they will look for strategies to teach them separately. If they appreciate the fact that everything in the world is interconnected, they can use history to teach math, math to teach science, and so on. Until teachers have an appreciation for this interconnectedness, they won't be able to call on strategies that involve teaching from this point of view. The challenge for teachers is to shift their views of how the world works.

Eric Jensen, your work translating brain research into classroom practice has led you to suggest ways that teachers might begin to think and act differently. Managing new approaches to teaching and learning requires a deep understanding of how the brain works, as well as an understanding of what motivates and engages people.

Eric Jensen: That's what I've seen. For years, many teachers have found that their Holy Grail has been attention. But evidence suggests that the brain's ability to stay attentive for extended periods of time is not only rare, but also difficult. The normal human brain works in periods of high levels of attention, followed by periods of low levels of attention. The brain needs downtime.

If you mean downtime during school time, that might be difficult for parents and the community to support. After all, aren't their tax dollars invested in teacher time on task?

Jensen: Downtime or processing time is something that most students take anyway. They'll just tune out what's going on. Downtime allows the new synapses that were formed to strengthen. They can only strengthen when no other neurostimuli are competing with them. Downtime has to be nonchallenging time. As soon as you create challenge, interaction, and feedback, it's not downtime; giving students 10 problems to do is not downtime. If you're introducing something fairly new and complex to students, they'll probably need more downtime more often than if you are reviewing material that they already know pretty well. You could be a great teacher and have the kids' attention only 20 or 30 percent of the time. At other times, students could process, write, work on projects, or peer teach.

How does tapping into students' interests help capture their attention?

Jensen: Anything that is emotionally laden will get our attention quickly. Teachers who know this have used it in the classroom for years.

Sylwester: That's true. Our profession has paid little attention to emotion. And yet, our emotional system drives our attentional system, which drives learning and memory and everything else that we do. It is biologically impossible to learn and remember anything that we don't pay attention to. The emotional system tells us whether a thing is important—whether we ought to put any energy into it.

We've basically ignored emotion for years. We didn't know how to regulate it, to evaluate it, or to measure it. We've told kids that school is for learning and memorizing, and if they want to have emotion, have it at recess or after school. Or, if we're going to have emotion in school, we'll put it in art class. The biggest single problem of our profession is that we never learned how to deal with emotion in school.

Jensen: I'm interested in the engagement of productive emotions. An excess of emotions would be counterproductive. Anger, rage, sarcasm, hate, violence—all these are absolutely forbidden. The opposite is also true: If somebody has a complete absence of emotions and can hit another student without remorse, that's dangerous, too. What we're talking about is a healthy middle ground. Students are emotional beings, physical beings, cognitive beings. If we are not engaging emotions, then students feel a void, which they will fill elsewhere—and it may not be in school.

What types of classroom activities could appropriately engage emotions?

Jensen: Productive debates where students pick sides and get vested; celebrations because the learning turned out to be joyous or a project was completed; storytelling that engages students; teacher role-modeling so kids see an adult act positively and productively with emotions. Kids need projects that include a public demonstration so that they experience anticipation, concern, excitement, and suspense.

What about the arts?

Jensen: Students need the arts because they are part of the foundation of learning, part of developing the brain. Music is a part of all of us, and it's critical to us as learners to develop pattern-making. Math and science tend to be stronger in students who have a music or an arts background.

Sylwester: Part of our brain is set up to deal with music and art. It wouldn't be there if it weren't important. If you don't stimulate the language centers of your brain to master language, you are in a deficit for the rest of your life. What about the music centers of your brain? A human brain isn't just about staying alive, for goodness' sake. A human brain is about the quality of one's life. The arts are very central to the spirit and the quality of our lives.

Given what we know now about the brain, how secure can we be about suggesting the practical applications of this information?

Sylwester: We ought to look at brain research as a way to simply explore ideas as they come along and try them out. Teachers have this marvelous brain laboratory in the classroom; they've got 30 brains floating around, four or five feet off the ground, 100 pounds of brain tissue that they can study all day long. They can look at these brains and engage them in activities; they can try to find out how students feel, how long they were able to stay attentive, and what they learned. That's what I think teachers ought to do.

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