If we stops the study of learning stops only on
genetic researches, thinking that we born born with immutable physical and
cognitive structures, given from the moment of conception, we can believe environment
is not so important, however, contemporary genetics
and studies on the human genome, provide novel approaches to the source, and
explain many pathologies, giving more
and more place to the experience of the individual and corners to a very
precise place to initial genetic determinism that held few years ago.
This suggests the possibility that brain
superior functions are based on a biological substrate clearly designed by the
genome, but the deployment and development of such capabilities of cognitive
abilities need essentially the
influence of the environment so much so that, without it, these functions may
be severely truncated.
In this sense, it is known some regulatory
genes susceptible to light only if they receive certain environmental signals,
thereby greatly the generation of synaptic connections and neural routes are
not provided in the basic design that are unique to each individual in relation
to the experience.
But how does this relate with our brain?,
well, as already mentioned, the human nervous system perceives, processes,
stores and create behavior in response to information received from the
environment, internal and external with the ultimate aim of ensuring the
conservation of the species, that learning is as important as a means of
stability, since the key brain capabilities level to develop skills for
individual survival (Avaria, 2005).
At the end, our nervous system is the supporting
material for knowledge, affection and behavior, along with genetics, and skills
will be developed for adaptation in the middle which will make us more or less
able to respond to the needs of the environment.
Of course is not possible to forget the role
of our genetics heritage from parents, so there is something called genetic
imprinting which is a phenomenon where certain genes are
expressed in a way specific, for example, if a parent inherits more genes with
certain features that the other is put in risk the brain and behavior of
children, resulting in several possible syndromes.
Some research found out that gene expression
plays an important role in brain development, in a way such that certain
regions of the brain are almost entirely controlled by the genes of the mother
and other regions, by the father (Wenner, 2009).
But once the environment comes in the
sequential and orderly development of the nervous system gives rise to a
fundamental concept, known as either critical
periods and sensitive periods .
This concept refers to the existence of determined
moments in the maturation of the nervous system that establishes the conditions
to achieve a particular function, what is really important in this aspect is
that if the structures related to a function remain deprived of the necessary
environmental influences for its development, this not will develop properly,
even if these influences can exert their action at a later period.
This knowledge came thanks to classical
studies which showed that if it was blocking an eye of a kitten during their
first weeks of life, this caused irreversible loss of vision in that eye due to
the decrease in synaptic inputs to cortical neurons from thalamus (Hubel &
Wiesel, 1970).
These studies led to think that childhood was
the only time critical development, but further investigations, particularly
those carried out through neuroimaging, for example some at the University of
California in los Angeles and at the National Institute of Mental Health in
Maryland, allowed to observe a second stage of growth of gray matter just
before puberty during which, our brain develops different to early adulthood.
Analyses show that the maturity of the grey matter, is not signal the end of
mental changes, but the ability to re settle and rearrange if same and that
this occurs during adulthood as a signal of the continuing brain development
for several years, being a reflection of the environmental interactions
(Shreeve, 2005).
This topic has received great attention, not
only from the scientific community, but also on the part of the media and the
community in general, developing related term of windows of opportunity, with important implications from the point
of view of education, especially preschool.
A well-studied aspect in this regard relates
to the acquisition of language, since it is thought that learning a foreign
language is only possible prior to puberty. However, studies with bilingual
populations have shown that learning is possible, but it is acquired with some grammatical errors and a notorious
difficulty in the structuring of phrases, as well as an accent.
Positron
Emission Tomography (PET) have shown that if a baby learns a second language,
all linguistic activity is located in the same area of the brain, while those
children who learn a second language later show two focuses of activity. Some
studies in this respect have found in English speakers a curious decodification
if the sounds R and L in separate parts of the brain, but these sounds are
processed in the same part of the brain in those whose mother tongue is Asian
because these languages do not distinguish between these phonemes (Kim, Relkin,
Lee. Et all., 1997; Chugani, Phelp & Mazziotta, 1987).
In this sense, the possibility of inducing a
greater number of connections and synapses through stimulation techniques has
been subject of much debate.
One of the attempts that has received a lot
of attention called Mozart effect, citing positive effects on cognitive
abilities and therefore a better overall performance of the individual against
multiple tasks.
However, a recent review concluded that there
is a specific improvement in the performance of visuospatial abilities after
hearing some pieces by Mozart, but
this effect has a short duration, no more than 10 to 15 minutes, which
minimizes management commercial that promotes the rapid achievement of higher
child intelligence (Avaria, 2005; Rauscher & Shaw, 1995; Chanda, Levitin,
2013).
Other studies analyze the
influence of the environment and have
focused on the development of gross motor skills, and what has been found is
that this does not require so much stimulation from the environment, so the
delay is usually due to biological causes, making it the exception to the idea
of the environmental stimulation.
While there is a normal
variation in the acquisition of the development in gross motor development
milestones, and the acquisition of the walking skills, this variation is lower than in
other areas. This was demonstrated in a study in 404 children with retardation
motor, at 18 months, a third of them children had failed to take 5 steps
independently, and eventually presented a pathology (Avaria, 2005)
Studies of children with
cerebral palsy, have allowed to observe the delay engine in any of its forms,
while infants show cognitive delay, thus found with gross motor development
within expected is not guarantee of normal cognitive development in the future.
Against, children with
mental retardation, in general acquire progress independently at later ages
that children with normal intelligence, but within each level of mental
retardation, there are children walking to comparable to normal ages. In this
sense, a study reported that only 62.2% of children with severe mental
retardation and 38% of those who have moderate deficiency, walking after 12
months, showing that motor development may be apparently normal the first year
of life, but cognitive retardation will be significant later in this population
(Avaria, 2005).
So we can say, different motor behaviors
allow to relate the maturation of cognitive process and the brain connections
product of environmental interaction, for example the use which makes the
child's hands in relation to the exploration of the environment.
The analyses that are made about the
disappearance of primitive reflexes and maturation of visual function, when the
nearby can be focused and achieved simultaneous information on the sight and
touch, which establishes the basis of future skills visomotoras which gives
opportunity that infant use your hands around three months together. It is so
from the 3 to the 6 months baby gradually accomplished prehension voluntary and
visually guided, first on the flat side and then in the middle line.
The acquisition of this skill, allows the
study of the inter hemisferic-dominance (being right-handed or left-handed)
which is not developed until after the first year, and is defined until after 2
years.
Therefore, the handling of objects reflects a
progressive understanding of the world that surrounds the infant. At 9 months
the child examines the objects in a systematic way, thanks to the ability to
process non-sequential and simultaneous information how did before developing
this skill.
Of
course this is very important as cognitive development, since around 9 months
will be handling the sense of permanence
of objects that demonstrates the symbolic objects representation and causation
from the Piagetian point of view, but confirm the consolidation of brain
connections that allow such processing (Avaria, 2005; Bloom, Beal & Kupfer, 2006).
In regards to the development of the
communication and language, this area is where the debate on the relative
importance of biological and environmental mechanisms in its development has
received greater attention. The question if cognitive abilities such as
language are the result of structures and genetically coded and specific
predispositions?.
It is thus that the abilities that children
acquire during the development are not only of maturation at the neurological
level, but are largely the result of the interaction with the environment. The
greater the stimulation that receives, more complete is the neurological organization
and better expectations for cognitive skills. In that sense, importance early
stimulation in early childhood (Ginarte, 2007).
But those who defend the genetic position can
add one more aspect to the discussion, and it is the role of the genetic influence,
particularly the studies on the genetic imprint, since these studies are that
the influence of paternal genetics plays a greater role in instinctive as
feeding behaviors or look for couple, while the maternal genes are concentrated
in the development of cognitive processes such as language and social
behaviours (Wenner, 2009).
The main response in this regard says: if the
brains of children are innately predisposed to learn the language, with the
proper exposure all children with normal brains must, without instruction,
learning the language in a relatively uniform manner.
If this hypothesis is correct, the capacity
to acquire language should be both anatomically and functionally autonomous of
other capabilities, and developing lesions or acquired can deteriorate, but
does not stop the process of acquisition, on the other hand specifically
preserve the ability to learn language.
If we accept the position that learning of
language ability is not innate, instruction should be required to learn it, the
course of the acquisition should vary considerably in each person (perhaps
depending on the quality of the instruction), and therefore there should be no
critical period for the acquisition, or the functional or anatomical
specificity of the language (Stromswold,
1995).
At this point, I can't avoid mention a classic
study in conducted around 1960 by Diamond,
this experiment analyzed the changes in the structure of the nerve cells in the
cerebral cortex of rats when they are exposed to what she calls an enriched environment or an environment depleted .
Rosenzweig (cited in
Aguilar, 2003) conducted experimental studies in animals, with an idea of
possible applications in human rehabilitation field. He proposed enriched environments
in a model with rats, living in cages with a number of toys and other stimuli
induce changes morphological, physiological, neurochemical and behavioral.
This was named as enriched environment if the rat
had a large cage and access to objects with that play and explore and also
socialize with other 12 rats. The objects had to be changed periodically so
that the challenge was greater. The impoverished environment was a small cage
with a single rat, without friends or toys (Diamond, 2001).
This experiment found out that animals
exposed to the enriched environment had developed cerebral cortex thicker than
rats that were in the impoverished environment. The dendritic branches in
cerebral cortex had grown as a result of interacting with other rats and
explore and play with objects, changes were observed primarily in visual, motor
and the frontal area, associated with socializing. They also found low levels
of neurochemicals associated with stress.
This study concludes that when nerve cells
are stimulated by new experiences and exposure to the incoming information from
the senses, it’s possible to grow dendritic branches. If rats continue in a
rich in the right environment, the branches grow and this creates greater
learning, while in an impoverished environment, these ramifications are pruning
to be lost.
Diamond (2001) also found something that was
not part of the original study, these same rats if were caressed, showed even larger
number of neural connections in the area of the limbic system, which is
associated with emotions, but also memory.
They are such situations that make me think that
genetics is so important when analyzing a learning problem, what should be the
position to a child with Down Syndrome or a child with autism when they have a
learning disability?, should we accept the idea of a genetic destiny?, can they
learn?. should we believe the theory of enriched environment and say that
genetics doesn't matter?. The function of the experience would be, in short,
the alter of locally and selective gene expression pattern in charge of the organization
and the functioning of a given brain region (Benitez - Burraco, 2006).
Some years ago I learned how to find the
right medium of this dilemma. Someone asked during a conference: what is the
difference between one and another position at the social level?.
The answer is that if we
accept the genetics, and I think most that most of people accept it, since we
change our faces and our voices when we see a child adding a poor boy, he has Down syndrome. Only few persons
will see what this individual is, instead of seeing how this person can be, so we accept the genetic influence as important.
But if we accept his Down's Syndrome but also this boy has capabilities that can
come to be exploited, is to accept the position of the enriched environment.
My question is: How do I know if I have the
skills to be high-level pianist if I've never have had the opportunity to be
near a piano?. So we should ask: what can I do for this child? Instead of
asking: what can this kid do?. It is seeing infants as human beings capable to
grow and create and think, and not to fall into the Protocol of applying tons of
tests to verify in a scientific way that
children have a language problem, or which are not suitable for math or the
arts.
Therefore the vision of the neuroscientific
posture is appealing to the brain and its ability to achieve neural
connections, based on the skills that you already own to this meet that cost
work or is even dreaming of having. Who was found with a good math teacher who
managed, that for a moment, we thought that numbers were simple, even to me?. Neuroscience appeals to the
principle of flexibility which is called plasticity,
to develop skills from strategies that enable each individual better understand
reality.
Each brain develops, grows, learns, observes,
understands differently. Some are based on visual clues, others are excellent
for understanding the logical way to world mathematics. Some are good to be
located geographically, while to others, we have the broken GPS. This is what
makes wonderful brain, can be molded plus enjoy this learning, and learning in
many ways. The children not only learn by repeating, learn again and again
playing with a Nintendo game. Even if adults like or not, children's brains generate
neural networks faster than us, take advantage of this window of opportunity is
the difference between suffering in school and enjoy school.
Some lessons require repetition, others
require understanding of its usefulness, while others are based on direct
experimentation. Cognitive goal tasks needs to recognize and apply the
necessary strategies is perhaps the differences between this child cannot learn and this
child learns differently .
References:
Aguilar, F. (2003) Plasticidad cerebral: parte 2. Revista
Médica IMSS. 41 (2) 133-142.
Avaria, M. A. (2005) Aspectos
biológicos del desarrollo psicomotor. Revista de Pediatría.
Electrónica. 2 (1). Disponible en red: http://www.revistapediatria.cl/vol2num1/pdf/6_dsm.pdf
Benítez – Burraco, A. (2006) Genes y lenguaje. Teorema
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Bloom,
F: Beal, M & Kupfer, D. (2006) The
Dana guide to brain health. Dana
Press. Estados Unidos.
Chanda, ML., & Levitin, DJ. (2013) The
neurochemistry of music. Trends in
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Chugani, HT., Phelps, ME, & Mazziota, JC.
(1987) Positron emission tomography study of human brain functional
development. Annals of Neurology. 22
(4) 487-497.
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Ginarte Arias, Y. (2007) La
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http://www.dana.org/news/cerebrum/detail.aspx?id=39360
Hubel D., Wiesel T. (1970) The period
of susceptibility to the physiological effects of unilateral eye closure in
kittens. Journal of Physiology. 30 (4) 206- 212.
Kim K., Relkin N., Lee K. et al. (1997) Distinct cortical areas associated with native and second
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