Nurturing brain development
by Prof Lise Eliot
In this competitive society, parents are anxious to know of ways to improve their
children's intelligence. Some would go to all lengths to help their children become
smarter.
Some of the questions that parents often ask are "What actually ordains a child's
intelligence - genes or the environment or both?" "What can they do to increase
their children's IQ?" "When is the best time to teach their children new skills?"
To give us a better insight into how the brain is wired and to share some practical
tips on how parents can optimize their children's brain development is Assistant
Professor Lise Eliot.
A/Prof Eliot is a neurobiologist and assistant professor in the Department of Cell
Biology and Anatomy at the Chicago Medical School. She is a graduate of Harvard,
received her Ph.D. in neuroscience from Columbia University and has published work
in this field in many professional journals. She is the author of a highly acclaimed
book "What is Going On In There? How the Brain and Mind Develop in the First Five
Years of Life" - a comprehensive account of how a child?s brain develops and ways
in which parents and caregivers can help their children grow better brains.
Interview with A/Prof Lise Eliot
by Sherlin S.C. Ong (Senior Regional Nutritionist/Dietitian)
M.S., R.D.
Q: What's the primary determinant of a child's intelligence - nature (genetic programming),
or nurture (environmental influences)?
A: Brain development, like all development, is a blend of nature and nurture, of
genes and environment. Genes prescribe the overall architecture and sequence of
brain maturation, but the environment acts at every step to modify those genetic
decisions.
Most human abilities (such as IQ, personality, verbal skills) are influenced about
50% by genes, and 50% by environment. Although geneticists are learning an enormous
amount about the human genome, we are still a long way from applying this knowledge
to improve developmental outcomes. On the other hand, we already know a lot of how
experience, or the environment acts on the brain, and there is a great deal we can
do to improve a child's environment, to optimize his brain development.
Q: How does the environment shape a child's brain development?
A: Neuroscientists have a special term to refer to the way the brain is modified
by experience, called "plasticity." Thanks to some 40 years of research on neural
plasticity, we understand a lot about how brain cells are molded by a person's life
history, from the earliest cell divisions to the end of life.
Each brain cell, or neuron, is shaped much like a tree, with two branching ends,
a root system known as the "dendrites," which receives information from thousands
of other neurons, and an output side, called the "axon," which branches out to send
information to hundreds or thousands more neurons. There are some 100 billion brain
cells in a human, a number that is reached by just 5 months' gestation in the womb.
So there are literally some quadrillion synapses or connections in a child's brain,
each of whose fate can be altered by a child's experience.
Synapses can be gained or lost, strengthened or weakened as a result of their own
electrical activity. We have a couple of useful phrases to describe this process:
"Cells that fire together, wire together." which means that synapses which are highly
active (for example, visual system connections in a child with normal vision) will
be preserved and strengthened.
On the other hand, synapses that are under-active, such as visual connections in
a child with a congenital cataract, will be pruned away, according to a "use it
or lose it" rule, forever threatening the child's ability to see out of that eye.
Q: Is the brain plastic throughout life or just during early childhood?
A: While all of a child's brain cells form by midway through gestation, the number
of synapses in a child's brain grows most dramatically after birth. In fact, children
overproduce synapses. Between roughly 2 and 10 years of age, a child's brain actually
contains some 50% more synapses than in the adult. These excess synapses provide
the raw material on which experience acts to shape a child'smental abilities. By
overproducing synapses, the brain creates an opportunity to select the most useful
or active connections.
Therefore, while the brain remains plastic throughout life, it is tremendously more
so in early childhood, because of all these excess synapses to choose from. Indeed,
there is good evidence that the period of synapse overproduction or, "exuberance,"
corresponds to the several "sensitive periods" in children's mental development.
Q: What would you suggest that parents do to stimulate their babies’ brain development?
A: Babies' brains need stimulation to develop properly, but luckily, most normal
caregiving activities provide the optimal stimulation. Thus, babies are born highly
attuned to human stimuli-- your face, voice, and touch, and it is through interaction
that they do their best learning.
Singing, talking, and reading to your baby are all ideal ways of stimulating his/her
senses. Babies are also highly responsive to motion-- gentle bouncing, swinging,
and being carried--because of their highly developed vestibular system (sensory
network that controls our sense of balance).
Even the fanciest toy is not as effective as a loving caregiver in optimally nurturing
a child's developing brain.
Q: The five senses that stimulate brain development are vision, touch, smell, hearing
and taste. Please elaborate on one or two of these senses and suggest practical
ways for optimizing a child’s brain development.
A: All five (or six, if you include vestibular sensation) of a baby's senses begin
working before birth, providing an important route for prenatal brain stimulation.
Of these, the chemical senses (smell and taste), together with touch and the vestibular
senses are the most precocious.
Let’s take a look at the sense of touch … The sense of touch begins working by the
first trimester of development in the womb. By birth, babies have experienced many
months of touch stimulation, all over their little bodies. After birth , social
touch is especially important for babies' development. Infants deprived of close
holding and contact can suffer all kinds of emotional and developmental problems.
When babies begin to grasp objects voluntarily (about 5 months), parents can provide
them with a variety of textures to explore-- rough, smooth, furry, sandy, etc. Infant
massage has proven highly beneficial for preterm infants and is a great form of
interaction and touch stimulation for children of all ages.
Vision is another important sense …Newborns do not see well at birth, but their
vision (acuity, color perception, depth perception) improves dramatically in the
first 6 months, largely due to an explosion of synapse formation in visual areas
of the cerebral cortex.
Young infants do not see well, but are very attracted to bold, highly contrasting
patterns. Therefore, to promote attentiveness, caregivers can use bold patterns
such as checkerboard, bull's eye, or a simple drawing of a face.
Q: Early childhood is the best time to acquire language skills. What can parents
do to enhance this skill in their children?
A: Language development is fascinating. Mastering a new language is hard, hard work
for an adult, and yet, toddlers manage it without any deliberate study or teaching.
That's because the human brain is innately biased for language.
Babies are riveted by human speech, and begin tuning into the sounds of their maternal
language almost from the moment of birth. They begin recognizing individual words
by 4-5 months, understand the meaning of words by 8-10 months, and begin producing
their own first words at around 12 months. By 24 months, most toddlers begin combining
words, talking in mini-sentences that already reveal the basic elements of grammatical
usage. While the human brain is uniquely prepared for language, children cannot
learn it in a vacuum.
There is a basic principle that "Language in = language out:" Children speak the
language (or languages, in the case of bilingual rearing) that they hear, and their
verbal skills are in large measure a function of the quality of their early verbal
environment. Children who are spoken to more, beginning at birth, show larger vocabulary
and later verbal IQ than children who are not as verbally engaged by their caregivers.
However, language stimulation must come in the context of loving, two-way interactions:
toddlers don't learn language by listening to TV or hearing adults converse among
themselves. They learn it when caregivers, peers, or siblings engage them in conversation
about feelings, objects, and events in their environment-- concrete, personal topics
that they can understand directly. They also learn it through our feedback--when
parents mimic their baby' babbling or respond to their earliest attempts at speech,
he/she learns that she is communicating effectively, motivating him/her to keep
it up. Language stimulation, in the form of loving verbal "dialogues," is the single
proven way to enrich children's later mental ability.
Parents can help their child develop their language skills by talking to their child,
no matter how young. Other activities include asking questions, engaging him in
conversations, reading and singing together.
Q: Finally, in a nutshell, what’s your advice to parents who wish to raise smarter
children?
A: Behavioral geneticists inform us that most cognitive abilities are roughly 50%
heritable or, attributable to the genes we are born with. This leaves the other
50% to be influenced by envirnoment--every physical, sensory, social, and educational
influence a child is exposed to from the moment of conception-- and it is here that
parents, teachers, and doctors can help make a difference in children's future abilities.
Prenatal experience accounts for a surprisingly large proportion of the variance
in intelligence in the population--perhaps 20% by some estimates. Preterm birth
is a well-known risk factor for neurological problems and mental impairment. The
more women can do to stay healthy during pregnancy, the better it is for their babies.
The list includes: eating well; getting enough rest and exercise; avoiding severe
stress, alcohol, tobacco, and illicit drugs; minimizing legal drug use and exposure
to other potentially harmful chemicals; and most importantly, avoiding infection.
After birth, one of the simplest ways mothers can help their children achieve a
few extra IQ points is by choosing to breastfeed for the first year of life. Scientists
have yet to elucidate exactly why breast milk is so advantageous for mental development,
but it is known to contain dozens of factors--specific nutrients, hormones, enzymes,
and immune factors--which are specifically beneficial to brain development.
Other factors in early childhood that are associated with greater cognitive achievement
include: a healthy environment (especially, free from second-hand smoke, lead, and
other heavy metals); loving, involved parents (and other caregivers) who talk, read,
and sing to their babies a lot; exposure to a variety of sensory and social stimuli
(but avoiding overstimulation); high-quality child care or nursery school; firm
but fair discipline; and high expectations of mature behavior.
The key to raising a smarter, happier child is loving interaction from parents.
Spend time together in positive ways, sharing an activity the child will enjoy.
Most importantly, model the kind of responsible, intelligent, and moral behavior
you want your child to emulate, since children learn most through the example we
set, rather than the specific teaching we attempt.