The required reading for this Forum is Chapter 13, Marian Diamond, Introduction and Chapter 1 in her book Magic Trees of the Mind. What is the neurological basis of Diamond's concept of brain
enrichment? What specific components of the brain
and nervous system are involved - what is its cellular basis, in terms of the structure of the neuron itself? What is the relationship between brain
enrichment and the organism fortunate enough to live in an enriched environment? What are some of the lines of evidence she cites in favor of this point of view? Is the concept of brain
enrichment important only for infants and young children? What are some of its implications for our educational system? For family life?
For this forum, each student is asked to write a Viewpoint contribution that deals with Diamond’s article, AND relates its themes to one of the enrichment readings in Chapter 14 (Linn, Healy, Kamii and DeVries on Children with Rollers, Borish on NCLB and public education). Or, you may relate Diamond’s work on brain
enrichment and the crucial nature of the enriched environment to any of the previous articles discussed in Units One or Two.
Form and requirements:
1) It must be at least 3 paragraphs long (it can be more, but not less)
2) Each paragraph must be at least 8 substantial sentences - full sentences, not sentence fragments.
3 There must be an empty, blank line between paragraphs.
4) You must check your spelling and grammar. Please use spellcheck, which means writing your essay in a word processing format and then posting it in Blackboard - an essay filled with spelling errors will not gain credit.
5) Your essay must contain DETAILED discussion, analysis and response to the reading in question. This means that I need to see at least two actual citations (more are even better) from the article - with page numbers from each citation (not from the same page). Actually citing a few words or a sentence from the article in quotes is REQUIRED as is the page number.
6) Writing a Viewpoint Essay for a particular reading must choose their citations from different pages. In other words, if you are writing on an author, you cannot use the same page numbers for your citations as those who have posted before you have done.
Example of a viewpoint essay: Use this as an example :
David S. Ludwig identifies four phases of the childhood obesity epidemic. He claims that the first phase began in the 1970s. The epidemic crosses cultural and economic classes as far as increase in average weight(s) overall. Ludwig asserts, Ã¢â‚¬A"Today, about one in three children and adolescents is overweight and the proportions approaches one in two in certain minority groupsÃ¢â‚¬Â. One in three is a huge number if we look at the American population of kids. (pg 2325) He points out that many of these kids remain and appear healthy for years, thus have no (apparent) influence on public health. Ludwig describes phase two is the phase he defines us being at presently. He states that this phase is distinguished by considerable weight related problems. Fatty liver related to being over weight, previously unrecognized in pediatric literature before 1980 has been reported as one in three- among the obese children population at the time of his article. He states, Ã¢â‚¬A"The incidence of type 2 diabetes among adolescents, though still not high, has increased by a factor of ten in the past two decades and may now that of type 1 diabetes among African American and Hispanic adolescentsÃ¢â‚¬Â. (pg 2325)
Phase three is defined as life threatening. Coronary heart disease, high risk for limb amputation, kidney failure requiring dialysis, and premature death are some of the consequences of childhood obesity at this juncture. He further points out, Ã¢â‚¬A"Fatty liver will progress to hepatitis and cirrhosis, which may remain asymptomatic until irreversible organ damage has occurredÃ¢â‚¬Â. (pg 2325)Ludwig believes that stage four has irreversible possibilities and outcomes. Children that are obese as children will most likely be obese into and throughout adulthood. He asserts, Ã¢â‚¬A"Carrying excessive weight in early in life may elicit irreversible biologic changes in hormonal pathways, fat cells, and the brain
increase hunger and adversely affect metabolismÃ¢â‚¬Â. Ludwig goes as far as to say that a parentÃ¢â‚¬â„¢s obesity can affect the Body Mass Index (BMI) of their newborn. In short, he terms this phenomenon perinatal programming. (pg 2326)
According to Ludwig, if childhood obesity is not prevented- the following consequences are eminent. He found that obese children tend to isolate and introvert in their childhood and into adulthood. Furthermore, he found that they are prone to live in poverty and not to complete education beyond high school. This is apparently an outcome of high anxiety and depression. He and his colleagues predict, Ã¢â‚¬A"Pediatric obesity may shorten life expectancy in the United States by 2-5 years by mid-century- and affect equal to that of all cancers combinedÃ¢â‚¬Â. (pg 2325) This article on childhood has direct implications on our communities. Wherever we live and whatever our economic status, we are all related to and/or have people that we love, care about, and are close to. LudwigÃ¢â‚¬â„¢s findings and reports can and will affect each and every one of us somehow. When he stated that he and his colleagues predict childhood obesity to equal the affect to that of all cancers combined, I had to do a double take. I have had two aunties in my immediate family and my grandmother battle with cancer. My grandmother actually died from stomach cancer partly because she didnÃ¢â‚¬â„¢t like hospitals and failed to report her condition. That is three people close to just me. For every Ã¢â‚¬A"meÃ¢â‚¬Â there is a Ã¢â‚¬A"youÃ¢â‚¬Â. Me and you makes a Ã¢â‚¬A"weÃ¢â‚¬Â. We need to take heed of this article and others like it in order to live and share a full- healthy life for ourselves and with others.
Marian Diamond is an internationally known brain
researcher who has been at UC Berkeley and she's been one of a number of people who've done groundbreaking research in the relationship between the brain
, growth of the brain
, or decline of the brain
, and the kind of environment that organisms are in. Her work not only has implications for humans
, but in fact I believe she did most of her work with rats. But as you'll see in her reading this concept of the enriched environment has implications for the relationship between the environment and brain
enrichment or brain
impoverishment. It is not only humans
that this theory applies to.
She begins, I'm going to start with the introduction, Experience is the Best Sculptor, and she says that we "once viewed the child's brain
as static and unchangeable" but we understand today it's a "dynamic organ that feeds on stimulation and experience." And what's different here about looking at the brain
development is we actually look at the brain
as an organ. We look and see that, in her language, "the flourishing of branched intertwined neural forests is what can be seen as the result of the proper relationship between the organism and environment at different stages of the life cycle."
She asks a number of questions on page three which are appropriate for you to look at and on the top of page three, "when it comes to the brain
, experience does it." So this is not something that is merely an unfolding of genetic patterns. The genes make possible the growth and development of the brain
but it is the environment and experience which channel it and which stimulate it, or do not stimulate it. She writes a little bit about this concept of the enriched environment. If you go to page five she says that one of her reasons for wanting to tell the enrichment story is how applicable it is to American education and American children. She says on page five, "the typical American child does not experience an enriched environment." I would like you to read her description in that paragraph and see if that corresponds to your own experience. And so we do not provide an enriched environment for most of our children. There are a few fortunate ones that do get it and maybe many fortunate ones do get it but perhaps even many more do not and so we hear about teen pregnancy, children living in poverty, delinquency, dropout rates, drug abuse, crime, failed teaching methods, the growth of prisons, and so on. And so this is her claim that, in fact, brain
enrichment when we're talking about human
development we needed a certain point to focus on what's known about the growth of the brain
We move from the introduction to Chapter One (which is the only chapter I've reproduced in this book), "Trees That Grow So Fair: Neural Forests of the Mind." She talks about herself and her interesting childhood and the fact that she became very interested in the hypothalamus, described on page 11 what its function is. She then describes her own life, her marriage to a nuclear chemist, and her arrival at Cornell University, and talks about events in her own life and her interest, on page 12, in the work of Krech, Rosenzweig, and Bennett, and for the first time seeing the link between what was physically there in the animal's brain
and its ability to learn. She went down to see them, she’d moved to Berkeley by this time, and talked about the work of a man named Donald Head. Head had made observations of rats who had been free-ranging and played with his own children versus laboratory rats and found that the free-ranging rodents ran a much better maze than the locked-up rats. And so from Head's observation his Berkeley team decided to raise baby rats in two kinds of cages: a large enrichment cage (this is on page 13) filled with toys; and a small impoverishment cage. The important thing there is that actually, when these behavioral differences in the groups on the basis of being put in different environments became clear, she then did research that involved removing the brain
of a deceased laboratory rat, and she says from both groups, carefully measuring the thickness of the cerebral cortex. The enriched rats had a thicker cerebral cortex than the impoverished rats. It was only 6% thicker but it was highly significant: 9 out of 9 cases showed this. She repeated the experiment and she says this is about 1963. Then in 1964 she was coauthor of a paper called "Effects of Enriched Environments on the Histology of the Cerebral Cortex. She then talks about giving a paper at the American Association of Anatomists in Washington, DC, and showing this evidence. At that time people were less receptive to women scientists than today and a man said, in a loud voice, "Young lady, that brain
cannot change." This is a point of view that's still with us today even though it is contradicted by an enormous amount of experimental evidence. So then this idea of brain
enrichment, she talks about the fact that this really involved the shattering of some dogmas that perhaps many of you have heard about as well, that, you know, the brains
can't get thicker, they're fixed, that we are loosing 100,000 brain
cells every day, and the brain
has an intelligence level fixed at birth and it can't change, except to go down after whatever age you pick (8, 10, 12, 14) and she points out that neurologists have measured the dwindling of brain
cells in rats and humans
over the typical lifespan. But she argues that her group's theory of enriched and impoverished environments could explain this by looking to the source of the experimental brains
. Before 1964 she says, the researchers didn't pay much attention to where a brain
came from. Researchers got (human
from coroners: indigents, alcoholics, and bedridden soldiers. Animal researchers housed mice, rats, and other lab animals in small sterile cages. So she says, "the neurologist's standard model was based on starving brains
." And she says, "when researchers collect brain
tissue from enriched research animals or from people who have lived healthy, mentally active lives, they do not find a thinning of the cortex or a relentless loss of neurons with age."
After this, the next section is called, "A Rodent's Brain
Revealed." I would like you to look at that and to study that picture of the rat's brain
on page 18.
I'm going to jump ahead to page 20 to, "The Heart of Enrichment, Nerve Cell Branching." I want you to look on page 21 at the diagram of a typical neuron, or nerve cell. Isn't it extraordinary that the egg and sperm which unite, two cells, contain the potentiality for cell differentiation for all of the thousands and thousands of different cell types that we find in an organism at different stages of its lifecycle development. One of these types is the neuron, of course, very critical, the cells that comprise the basis of the nervous system. The heart of enrichment, she says, is nerve cell branching. So take a look there: the cell body in the middle, the long thin axon going down with branches, and then at the top of the picture the dendrites, which, she describes them, the "luxuriantly branching dendrites, and its thorn-like spines that grow, change shape, or shrink." So look at the dendrites and notice the spines on the dendrites.
Down at the bottom of page 22 she says some interesting descriptions of the brain
and I'd like you to pay attention to the bottom of page 22, "surface areas," and the fact that this concept of surface areas is necessary to understand how plant leaves collect solar energy and they are necessary to understand how our lungs absorb oxygen and liberate carbon dioxide or our small intestines liberate food. But nothing, she says, holds a candle to the human brain
. So please do look at that concept of surface areas.
Holloway's work on page 23, the branching in part was causing the cortex to grow thicker. Diamond had speculated that the branching of dendrites might explain this additional 6% thickness of the enriched cerebral cortex. And she suggests the term "little trees" on page 23 and this is well worth reading.
Go to page 25, "Nubbins, Umbrellas, and Lollipop Trees." These are her colloquial terms for what can happen to the dendritic spines. But first it is necessary to understand the term "synapse." I would expect many of you had this in elementary biology courses but it is good to review it. When the electrical signal traveling down the axon reaches the button-like ending at the wire's terminus, a chemical message crosses the gap in the synapse and we get the neurotransmitters.
Turn to page 26. Again I'd like you to be familiar with the diagram there:
• the sending nerve cell,
• the axon
• notice the little circle where the axon is adjacent to the dendritic spine and then the big circle that magnifies that
• electrical input from the sending nerve cell
• the release of neurotransmitters
• the electrical output from the dendritic spine
As you read this right now, probably hundreds of thousands of such electrical inputs are simultaneously being transmitted along the neurons of your brain
at every level from the peripheral nervous system, through the spinal cord, through the brain
stem, the medulla, through all of the different structures such as the thalamus, hypothalamus (that regulate thirst, hunger, and so on), through the limbic system and its amygdala (that is primarily connected with feelings), and through all of the different parts of the cerebral cortex (which regulate fine movement, perception, thought, and so on). All of this, this is the mechanism through which this text plays, the neurotransmitter. You begin to understand then what Parkinson's disease is a disease where dopamine, one of the main transmitters, is not being produced and this leads to failure, in particular, of motor neurons. So it is very important to understand what this simple but correct model of neurons and how they interconnect.
On page 26 and 27, the Diamond group and other researchers found that bees' dendritic spines themselves grow, change shape, or shrink as an animal experiences the world. The work of James Connor is important, how social isolation could affect a rat's brain
, especially in an elderly rat. Two groups of advanced-age rodents, some housed with their aged friends, others alone. When the animals died he found that spines resembled either three-dimensional lollipops with the ball on the stalk like Tootsie-Pops or they were short squat nubbins with no stalk. And the older rats alone had a lot of these nubbin spines, so could there be various lollipop shapes depending on experience in a lonely deprived animal? Could the lollipop spines go unused and eventually collapse into gnarled old nubbins? This is her statement of what the primary mechanism is of either brain
enrichment or brain
impoverishment, that it has to do with changes that are produced in the dendritic spines which affect the process of neural communication and pathways in the brain
. She then cites the work of Richard Coss on page 27. Bees that made one single flight out into the meadows were very different in what had happened to their dendritic spines than bees that had remained in the hive permanently. The Coss team found that a number of spine shapes, not just lollipops and nubbins, depending on the bees' level of stimulation from the outside world. I would like you to look at this. This is very important. Experience, even an hour or two of flying through the meadow, had a dramatic enlarging effect on a bee's dendritic spines. Coss found similar changes in the dendrites of socially enriched and deprived jewelfish. Another team found changes in young Myna birds, and so on. So this is really important.
On page 29 there is a marvelous quote from Richard Coss, who says, "an animal is only as smart as it needs to be." And Diamond goes on to add that a nurse bee inside the hive just apparently doesn't need to be as smart as the worker buzzing through the meadows and orchards. So, "just as the muscles are programmed to grow smaller and weaker with disuse, the dendritic trees and spines will shrivel and the cortex grow thinner with lack of mental activity," she tells us also on page 29. So the implications of this are clear, I believe, that we really need throughout the lifecycle to think about this question of the enrichment environment because it is the environment and our relationship with the environment which is the key overriding factor in determining what kinds of changes will or will not happen in our dendritic spines, which in turn affect neural pathways, which in turn affect every aspect of our human
life experience from the maintenance of our intelligence, to our motor coordination, to our interest in life, to our interaction with others, and so on.
In page 30 under the heading "Rats Revisited," she gives on the next two pages quite a good summary of the work of the Diamond lab group at UC Berkeley. They studied enrichment and impoverishment with great intensity. They wanted to learn everything. So they split animals into three groups:
1) A standard intermediate condition with three rats in a small cage with no toys,
2) Impoverishment conditions with a solitary rat in a small cage without toys, and
3) An enrichment condition in which 12 rats inhabit a much larger cage with a rotating array of toys such as exercise wheels, platforms, and ladders.
She tells us on page 30 the findings are potentially valid for students in dormitories, prisoners in solitary confinement, senior citizens living together in comfort or in poverty, for children treated well or abused. And so with the three cage types they formulated the basic principles of brain
enrichment and these are on page 31. I would like you to study these and think about them and use them as a basis perhaps for your viewpoints and responses. Remember also that the Wiki project, which I have asked you all to start thinking about during the past weekend this week, the Wiki project asks you in some way, whatever your chosen topic and problem formulation is, in relation to human
development, asks you in some way to relate it to the concept of the enriched environment. So what she says on page 31, "the impact of a stimulating or boring environment is wide-spread throughout the regions involved in learning and remembering." How interesting, a stimulating environment or a boring environment. I ask myself, is this the limit of the different kinds of environments that one could have? I ask, for instance, what about the type of environment that prisoners at Abu Ghraib had where they were subjected to many forms of humiliation and torture? They were certainly being stimulated in many cases, it certainly wasn't boring, and so we could certainly have a broader discussion of environments. But stimulating or boring is probably a good place to begin. Neurons in other parts of the brain
besides the cerebral cortex can also respond. I should tell you that there has been peer-reviewed work showing that actually new neurons can be generated in the adult phase of the lifecycle even though Diamond's model focuses primarily on the dendritic spines and this seems to be the key area. The paradigm shift has been so great in brain
research, the older view that the brain
with no more neurons growing after a very early age and development and then the death of 100,000 cells a day. You might hear this in the popular press. You might hear this by people with different kinds of theoretical or social axes to grind, but in fact even at the level of new neuron production it is clear now that, not only in humans
but also in other organisms, entirely new neurons can be produced in the adult phase of the lifecycle. I'll try to put up an electron micrograph picture of one of these for you.
Enriching the environment of a pregnant female rat can result in newborn pups with a thicker cerebral cortex. Now that's interesting, isn't it? Nursing rat pups show the effects of enrichment on the brain
and the impact of boredom in young and adolescent rats, a boring environment had a more powerful thinning effect on the cortex than an exciting environment had on cortex thickening. Now what are the implications of this for the kinds of education that we are giving our children? One of the mathematics teachers, a third grade math teacher with 22 years experience, complained about the kind of impoverished environment for teaching mathematics that is now mandated because of the dominance of the standardized testing and she said, in her words, "what we do now is drill and kill." In her school, pardon my small diversion here but some of you might want to talk about this in your viewpoints and responses, that in effect for these third graders school has become an experience where they are tested and the testing becomes much more important than the learning process to the despair of good teachers and to the confusion of new teachers who may begin to wonder what they got themselves into. In this third grade school not only do they have the week or more of standardized tests but they have trimester tests given three times a year, each one of which takes a week to prepare the students for the standardized tests. They have pre-testing and post-testing and they also have individual teachers' tests. So this is a situation, widespread in American education, where assessment has replaced learning. Assessment is the goal, learning becomes secondary. I wonder about the effect of the boredom that I would imagine that this is having for the students who have to adapt to something in these classrooms that is presenting itself to them as education. Of course, what about adolescence? I would be interested to have some of your views on this, speaking from your own experience.
And the last one, brain
changes were found in young adult rats, middle-aged rats, and even in rats the equivalent of 90-year-old humans
. Use it or lose it. The question remained, does a thicker cortex mean a smarter animal? The answer the Berkeley group says according to its data, "Yes!" And she gives examples of that.
That really sums up the essence of this argument that Diamond makes about brain
enrichment. I would like you to read and study her article carefully. Think about this in relationship to the other parts of Unit One and Unit Two, the importance of birth bonding, the nature of attachment bonding, all of these kinds of questions. Now we have a third perspective on human
development based on the concept of brain
enrichment or brain
impoverishment and that is really all that I will talk about today. Thank you.
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