Biological Bases of Cognitive Development
Why would we need to understand the brain to
understand children’s thinking processes?
Certainly the brain influences our behavior, but
repeated behaviors influence the development of
the brain. It is being noted that serial killers have a
significant part of the limbic system which modulates
emotionality which is deteriorated to the point of
nonfunctionality. This appears to be the result of
repeated abuse in childhood. The part of the brain
that produces empathy for the weak and wounded,
simply never develops since the child was offered no
empathy when s/he was wounded by abuse.
But one must also know the effects of various
modalities of education, therapy, etc, to be able to
design interventions that ideally support the
development of the brain and its functions.
Developmental cognitive neuroscience has
begun studying the brain-cognition relations during
development.
Evolution and Cognitive Development
Is it possible that certain learning styles and
techniques are more adaptive, aid survival better than
others? It’s suggested that women learned to talk to
better nurture their children and to connect with other
women out gathering food. Women who didn’t learn
to talk, died out and their traits weren’t passed on..
Evolution is the process of change in gene
frequencies in populations over generations. The
theory began with Darwin in 1859 (On the Origin of
Species) The process of natural selection is the idea
that traits of survivors get passed on down the gene
line, thus making the species more hardy, survivable.
This is called reproductive fitness, which means the
likelihood that a person will live long enough to
reproduce. This theory gives us a framework for
explaining behaviors in current use- how they came
to be and why they are useful. Is there some adaptive
benefit to developing empathy? Intelligent
understanding of human behavior can allow us to
anticipate another’s behavior and not be upset by it. It
also allows us to understand that some of our
ingrained behavior may no longer be adaptive (our
metabolic slowdown during dieting is
counterproductive to losing weight, although in the
past it allowed us to survive malnutrition.)
Evolutionary psychology studies cognitive
operations as well as overt behaviors in order to
understand how we develop and how childhood
thinking differs from adult thinking. In what way is
early childhood thinking actually adaptive to the
demands of their environment?
Darwinian algorithms are the evolution of
certain cognitive abilities in order to deal with
specific problems. These abilities are independent
intellectual skills. Modules or brain organs developed
in the brain to handle certain problems. (The limbic
system is ideally developed to handle emotional
responses to threat, affection, sexual desire, appetites)
This shaping occurred through natural selection.
There are also constraints on learning. In other
words, the brain is more likely to learn certain things
than others. This filtering system keeps us from being
overwhelmed by incoming stimuli. We learn to focus
most attention on things that may be most valuable.
Biologically primary abilities-cog. abilities that
were selected for by evolution (language)
Biologically secondary abilities-skills that build
on these primary abilities, but are cultural inventions
(written language) and are somewhat culture-specific.
So people choose environments, and then the
environment works on the person to instill unique
abilities. It is bi-directional, since the person also
modifies the environment by his/her presence.
Selectionist Theories of Cognitive and Brain
Development-they operate in a positive way
(survival) and a negative way (death and extinction)
Selectionist theories suggest that there is much
variation within any person, behaviors that are
successful are repeated, those that aren’t successful
aren’t repeated. So you witness children operating at
trial-and-error levels in the beginning before they get
efficient at solving problems. (Classic Skinnerian
operant reinforcement theory) The adaptive strategy
choice theory also suggests that cognitive operations
vary among people and vary with age and
development. (once you find a more efficient,
sophisticated technique, you forget or dismiss more
cumbersome techniques of your youth.) Add to that
the idea that the problems evolve with our age and
environment and you can see much flexibility offered
by the human neural system.
Models of Gene-environment Interaction
These theories see the child as active in his/her
own development, as well as seeing context as being
as important as genetic inheritance.
 Developmental systems approach
 Genotype  environment theory
Developmental systems approach views
development as occurring within a system of
interacting levels. Epigenesis is the emergence of
different, new structures and functions during
development. It sees biology and environment as bidirectional and influencing both structure and
function. This influence goes all the way down to the
cellular level. This is a complex interaction that is not
easily understood when trying to analyze the
individual. Four basic elements are: environment,
behavior, neural activity, genetic activity. It’s also
true that we inherit a species-typical environment that
selects behaviors that fit our species, narrowing
variation. It takes both to produce somewhat
successful and conforming behaviors. (Pre-hatched
ducks prevented from hearing their mother’s call
don’t produce adaptive behavior of following the
mother’s call after hatching.) There are asymmetries
in function of the brain that aid cognitive function if
they develop appropriately (left brain, right ear for
language, right brain for recognizing faces). This
pattern develops because of the pacing of brain
development in the womb. Developmental timing is
the idea that there are critical periods (or sensitive
periods for humans) in development that are ideal for
certain skill development. The specific skill is most
easily acquired if practiced during this period.
Language is easiest to learn from ages 2 – 4. it’s
possible to learn language later, but fluency will be
lost. Part of the ease of learning a critical skill at the
right time is that the sensory system may not be as
well developed in other areas, leaving maximum
cognitive power available to the developing skill.
A related concept is “Is it always helpful to try to
train infants in skill development at an early age?”
Research suggests it is not helpful, if the child does
not have the natural ability to learn a skill at that age.
It may be sensory overkill. This may be the reason
for cognitive deficits for preemies. Their brains are
being forced to process too much perceptual
information before they are ready, resulting in
learning disabilities. So pushing kids into cog.
stimulation courses may be counter-productive in the
long run.
Genotype  Environment Theory
Behavioral genetics studies the genetic effects
on behavior and psychology. It is hard for
psychologists to embrace the idea that genetics
determines very much of our psyche, since it seems
to mitigate the influence of environment. But more
information is coming out to show similarities of
identical twins raised apart. This theory suggests that
one’s genotype (genetic inheritance) influences
which environments we face and the experiences we
have. Genes drive experience. (We lean toward
experiences in the areas of our greatest abilities and
interests.) These genetic effects are:
 Passive-when genetically related parents
provide the rearing environment for the child
 Evocative-when the child elicits responses from
others based on his/her genotype. (Difficult
temperament child will affect parents’ treatment
differently than an easy child.)
 Active-when one’s genotype affects the type of
environment one chooses to experience (A shy
child refusing to try new or social things.)
Another effect from this theory is the idea that
parental influence will be greatest with young
children, decreasing as children become more active
in selecting their environments. Also environment
has less effect as genetics comes out more freely
(further into adulthood). Experience does shape the
development of a skill, such as IQ abilities.
“Good Enough” parents- because the genotype is so
influential, reasonably good parents will have about
the same effects on a child’s development as ‘superparents’. Other theorists have criticized this idea,
giving credit to good parenting as making a
difference. Scarr makes the point that there is a huge
diversity of parenting around the world and children
grow up well in a variety of settings. Our species is
remarkably flexible, or else it would not have
survived. Even so, children in a culture deprived of
the majority of benefits of the society will grow up
with certain deficits due to lack of stimulation.
Research on “resilient children” shows that children
can grow up successfully despite a poverty of rearing.
Yet the single most significant dynamic in
successful development is competent parenting.
Most parents have enough parenting motivation to do
a reasonable job.
The Development of the Brain-the brain develops
much faster than the body in general. Even so, at
birth the brain is very underdeveloped. The cerebral
cortex, the thin cover of the brain responsible for
higher thinking, developed most recently
evolutionarily. It separates us the most clearly from
the lower animals.
Neuroimaging techniques used to see the brain
working on tasks.
 EEG
 PET
 FMRI
Neuronal development-our neural system is
designed for communication – it is exquisitely
irritable and conductive.
 Neuron – 10-100 billion neurons in the CNS
 Synapses – connecting sites between the neurons
 Dendrites – receptor part of the neuron that
transfers the impulse to the cell body for
processing – either the impulse is sent down the
axon, or it stops at the cell body. Processing is
one-directional.
 Axon – the long fiber that carries the impulse on
to the synapse to stimulate the next neuron
 Neurotransmitters – are what facilitate the
neural impulse within the synapse. Different
neurotransmitters affect different neural abilities
(some enhance memory, others control
coordination, others exude a feeling of calm)
Neural impulses are all a result of
neurotransmitters being dumped into the
synapses and stimulating reception by the
following neuron. It’s a chemical connection.
Stages of development of the neuron:
 Proliferation-cell division during prenatal
development. By the 7th mo. of gestation most
neurons are formed and few others will form.
 Migration-cells move to where they will be
located permanently and begin their unique
functioning within that organ structure. Most
migration is finished by 5 mo. after birth. Some
mental disabilities are due to faulty migration.
 Differentiation-neurons begin connecting and
extending dendrites as they are stimulated.
Repeated stimuli produces smooth neural
connections (ruts, if you will) which allows for
efficient functioning.
Synaptogenesis-process of synapse formation occurs
rapidly in early years of life while the brain gets
organized, in response to different stimuli. Different
parts of the brain develop at different times. Visual
cortex development occurs bet/ 4 and 12 mo. There
are actually more synapses formed than the adult
brain will use.
Selective cell death- synaptic pruning occurs when
cells die because they aren’t being stimulated. They
die to make room for more connections between the
cells that are being stimulated. So the greater variety
of stimulation the child is exposed to, the greater
dendritic connections made, and the more cells
develop.
Experience-expectant processes- Evolution
prewires the brain to develop in a normal way, given
normal environmental stimuli. Experiments that have
restricted normal access to stimuli in newborn
animals show that their sensory systems don’t
develop well enough later to allow for full
functioning. (Kittens raised in the dark later can’t
make clear visual discriminations, since that system
doesn’t develop adequately without an adequate
variety of stimulation) (At First Sight- person blind
for 1st 50 years having vision restored still doesn’t
have accurate depth perception)
Experience-dependent process-there are unique
experiences of individuals that produce unique
neuron development. Neural Darwinism says that
we come into the world with many more neurons
than we need, and they compete to survive.
Stimulated neurons recruit nearby neurons to connect
in a complex group response. Cells not stimulated
simply die to make room. So if activity changes, it
changes the cells that are stimulated, producing new
patterns of brain organization. Experience sculpts
the brain.
Neural constructivism-little in the brain is
hardwired to only be used in one way. Function
comes as a result of use. (Blind babies show much
broader physical space used in the brain for
processing sound than in seeing babies. This is the
idea of compensation when there is a disability.) This
shows that the brain is not a static organ. It is subject
to reorganization due to stimuli. This is where PT and
OT therapies can make such a difference in
functionality.
Not only are early childhood brains full of more
neurons than adults, they also work faster- PET scans
show that glucose consumption is 150% of adult rate
and doesn’t slow down until age 9. This may be
necessary due to the vast amount of learning
happening at this point (language, coordination)
Myelination-myelin is a fatty substance laid over the
axon in certain neurons. It allows the neural impulse
to pass faster. The process begins prenatally and on
into adolescence. Different structures of the CNS are
myelinated at different times in development. When a
system is being myelinated, rapid spurts of abilities
will occur. (Frontal lobes finish myelinating in the
teen years, promoting a spurt of higher mental
activity, such as debate, problem solving, future
planning.) Loss of myelin (MS sufferers) may result
in loss of function, temporarily or permanently.
Experience seems to affect how much myelin is laid
down. Genetics affects it primarily, but it also
depends on a high fat diet in infancy, particularly one
rich in Omega 3 fatty acids. One reason breast milk is
so good for babies.
Structure of the Brain
 Neocortex (cerebral cortex)-neurons that sheath
the entire brain, very thin, but very complex in
function – higher functions such as planning.
o Hemispheres- cortex is divided into halves
and specific regions related to sensory
reception or motor functions.
o Corpus Callosum-thick band of fibers
connecting the right and left halves of the
brain, allowing coordinated responses.
Cerebral Lateralization-specialization of the
hemispheres into management of specific functions
by specific sides of the brain. Left hemisphere
usually controls production and comprehension of
language and semantics. The right side manages
nonverbal, spatial and visual information. This
process takes years and isn’t complete until
adolescence. Also, if trauma destroys parts of the left
side, the right side can take over those skills.
Lateralization does appear somewhat present at birth,
particularly in response to sounds heard by the right
ear instead of the left ear. This seems partly due to
whatever side the fetus lies on in the womb affects
brain dominance. People use the information coming
from both sides of the brain differently. The left brain
processes more analytically and sequentially; the
right brain processes holistically, simultaneously. To
achieve high levels of reading comprehension,
though, it takes both types of processing. Even SES
affects brain processing. Hi SES kids rely on the left
brain more than the right.
Plasticity-ability to change, especially within the
CNS. Experience forces new synaptic connections.
This has been demonstrated in rat tests (arid vs.
stimulating environment). Rats coming out of the
enriched environments showed thicker cortex, larger
neurons, more dendrites and more synapses. (20 –
25% more synapses per neuron) Plasticity is greatest
in infancy. Even so, later in life, intense experience
can force change in the brain. (Hemispherectomies
are possible even as late as 6 years old.) Damage to
more general processing areas may have more longterm effects, though. (Long-term impairment of IQ)
The effects of early deprived experience can be
reversed if the environment changes enough.
Vietnamese children who were malnourished and
deprived were adopted into middle class US homes &
showed normal IQ after 2 years of adoption. This is
partly due to the slow growth of the brain, even into
adulthood. This allows for flexibility in the face of
the environment. This also means that it takes more
effort to learn as a young child, because speed of
processing is so much slower. Older children have
more myelinated neurons and so can develop
automatic techniques for learning new things. Young
children’s processing is more effortful. Automaticity
is less flexible, though, meaning that later in life it is
harder to adapt to new things and training.
New Research Findings;
 Areas of the brain used for processing
temporal-spatial information also process
music. Could exposure to certain music enhance
the abilities to process math and 3D problem
solving? Findings: Listening to Mozart improved
adults’ temporal-spatial abilities. Children who
were taught piano showed improvement on
puzzle assembly tasks, but listening to music had
no effect. Children who had music/arts training
along with regular education significantly
improved their math performance after one year.
(So one of the first programs to be cut when
there’s a budget crunch in schools is the arts.)
 Prenatal hormones influence fetal brain
development- androgens masculinize the brain
and create gender differences in thinking and
skills. Male brains have an advantage in spatial
thinking. Female brains process information
more homogeneously. Male brains are more
lateralized.
Studies of brain development patterns can
enhance how we teach children and help all
children to reach their greatest potential.
Why Do you need to know about the brain to
understand cognitive development in children?
Biological Bases of Cognitive Development
Why would we need to understand the brain
to understand children’s thinking processes?
Biological Bases of Cognitive Development
Why would we need to understand the brain
to understand children’s thinking processes?
Certainly the brain influences our behavior,
but repeated behaviors influence the
development of the brain. But one must also
know the effects of various modalities of
education, therapy, etc, to be able to design
interventions that ideally support the
development of the brain and its functions.
Developmental cognitive neuroscience has
begun studying the brain-cognition relations
during development.
Evolution and Cognitive Development
Evolution is the process of change in gene
frequencies in populations over generations.
Natural selection is the idea that traits of
survivors get passed on down the gene line, thus
making the species more hardy, survivable. This
is called reproductive fitness, which means the
likelihood that a person will live long enough to
reproduce.
Evolutionary psychology studies cognitive
operations as well as overt behaviors in order to
understand how we develop and how childhood
thinking differs from adult thinking
 Darwinian algorithms are the
evolution of certain cognitive abilities in
order to deal with specific problems.
 There are also constraints on learning.
In other words, the brain is more likely
to learn certain things than others.
Biologically primary abilities-cog. abilities that
were selected for by evolution (language)
Biologically secondary abilities-skills that
build on these primary abilities, but are cultural
inventions (written language) and are somewhat
culture-specific.
Selectionist Theories of Cognitive and Brain
Development-they operate in a positive way
(survival) and a negative way (death and
extinction)
 The adaptive strategy choice theory also
suggests that cognitive operations vary
among people and vary with age and
development.
Models of Gene-environment Interaction
These theories see the child as active in
his/her own development, as well as seeing
context as being as important as genetic
inheritance.
 Developmental systems approach
 Genotype --> environment theory
Developmental systems approach views
development as occurring within a system of
interacting levels.
 Epigenesis is the emergence of different,
new structures and functions during
development. It sees biology and
environment as bi-directional and
influencing both structure and function.
 Four basic elements are: environment,
behavior, neural activity, genetic activity.
 It’s also true that we inherit a speciestypical environment that selects behaviors
that fit our species, narrowing variation.
 There are asymmetries in function of the
brain that aid cognitive function if they
develop appropriately (left brain, right ear
for language, right brain for recognizing
faces). This pattern develops because of the
pacing of brain development in the womb.
 Developmental timing is the idea that there
are critical periods (or sensitive periods for
humans) in development that are ideal for
certain skill development.
Genotype  Environment Theory
Behavioral genetics studies the genetic
effects on behavior and psychology. This theory
suggests that one’s genotype (genetic
inheritance) influences which environments we
face and the experiences we have. Genes drive
experience. (We lean toward experiences in the
areas of our greatest abilities and interests.)
These genetic effects are:
 Passive-when genetically related parents
provide the rearing environment for the
child
 Evocative-when the child elicits responses
from others based on his/her genotype.
 Active-when one’s genotype affects the
type of environment one chooses to interact
within.
Another effect from this theory is the idea that
parental influence will be greatest with young
children, decreasing as children become more
active in selecting their environments.
Experience does shape the development of a
skill, such as IQ abilities.
“Good Enough” parents- because the genotype
is so influential, reasonably good parents will
have about the same effects on a child’s
development as ‘super-parents’. Other theorists
have criticized this idea, giving credit to good
parenting as making a difference.
Research on “resilient children” shows that
children can grow up successfully despite a
poverty of rearing. Yet the single most
significant dynamic in successful development
is competent parenting. Most parents have
enough parenting motivation to do a reasonable
job.
The Development of the Brain-the brain
develops much faster than the body in general.
Even so, at birth the brain is very
underdeveloped.
Neuroimaging techniques used to see the brain.
 EEG
 PET
 FMRI
Neuronal development-our neural system is
designed for communication – it is exquisitely
irritable and conductive.
 Neuron – 10-100 billion neurons in the
CNS
 Synapses – connecting sites between the
neurons
 Dendrites – receptor part of the neuron that
transfers the impulse to the cell body for
processing – either the impulse is sent down
the axon, or it stops at the cell body.
Processing is one-directional.
 Axon – the long fiber that carries the
impulse on to the synapse to stimulate the
next neuron
 Neurotransmitters – are what facilitate the
neural impulse within the synapse. Neural
impulses are all a result of neurotransmitters
being dumped into the synapses and
stimulating reception by the following
neuron. It’s a chemical connection.
Stages of development of the neuron:
 Proliferation-cell division during prenatal
development. By the 7th mo. of gestation
most neurons are formed and few others will
form.
 Migration-cells move to where they will be
located permanently and begin their unique
functioning within that organ structure.
 Differentiation-neurons begin connecting
and extending dendrites as they are
stimulated.
Synaptogenesis-process of synapse formation
occurs rapidly in early years of life while the
brain gets organized, in response to different
stimuli. Different parts of the brain develop at
different times
Selective cell death- synaptic pruning occurs
when cells die because they aren’t being
stimulated.
 Experience-expectant processes- Evolution
prewires the brain to develop in a normal
way, given normal environmental stimuli.
 Experience-dependent process-there are
unique experiences of individuals that
produce unique neuron development.
Neural Darwinism says that we come into
the world with many more neurons than we
need, and they compete to survive.
Experience sculpts the brain.
Neural constructivism-little in the brain is
hardwired to only be used in one way. Function
comes as a result of use.
Not only are early childhood brains full of more
neurons than adults, they also work faster- PET
scans show that glucose consumption is 150%
of adult rate and doesn’t slow down until age 9.
This may be necessary due to the vast amount of
learning happening at this point (language,
coordination)
Myelination-myelin is a fatty substance laid
over the axon in certain neurons. It allows the
neural impulse to pass faster.
Structure of the Brain
 Neocortex (cerebral cortex)
o Hemispheres
o Corpus Callosum
Cerebral Lateralization
Plasticity
Why Do you need to know about the brain to
understand cognitive development in
children?