Debunking the Myths
From a Reuters
news service story, Children Do Not Have Learning Window comes
this quote,
'Stories stressing
that children's experiences during their early years of life will ultimately determine
their scholastic ability, their future career paths, and their ability to form
loving relationships have little basis in neuroscience,' Bruer
wrote.
The gentlemen referred to above is Dr
John Bruer, president of the James S McDonnell
Foundation of St Louis, Missouri.
Dr Bruer has recently released two papers, Education
and the Brain: A Bridge Too Far and Put
Brain Science on the Back Burner. Education and the Brain may
be ordered by going to the James S McDonnell Foundation web site (see below); Put
Brain Science on the Back Burner may be downloaded from this site.
Dr Bruer
expands on the above Reuters quote in both papers. In speaking to the claim that early
childhood experiences effect early childhood brain development, Dr Bruer states,
The argument runs as follows. Starting in early infancy, there is
a rapid increase in the number of synapses or neural connections in children's
brains. Up to age 10, children's
brains contain more synapses than at any other time in their lives. Early childhood experiences fine-tune
the brain's synaptic connections.
In a process that we might describe as synaptic pruning, childhood
experiences reinforce and maintain synapses that are repeatedly used, but snip
away the unused synapses. Thus this
time of high synaptic density and experiential fine-tuning is a critical period
in a child's cognitive development.
It is the time when the brain is particularly efficient in acquiring and
learning a range of skills. During
this critical period, children can benefit most from rich, stimulating learning
environments. If, during this
critical period, we deprive children of such environments, significant learning
opportunities are lost forever. [1]
Dr Bruer
breaks this argument down into three "misconceptions":
What little direct evidence we have - all based on studies of monkeys
- indicates that these claims are inaccurate. ... The rate of synapse formation
and synaptic density seems to be impervious to quantity of stimulation. The rate of synapse formation appears to
be linked to the animals' developmental age, the time since it was conceived,
and to be under genetic control. It
is not linked to birth age and amount of post-natal experience. Some features of brain development,
including the rapid burst of synapse formation in infancy and early childhood,
rather than being acutely sensitive to deprivation or increased stimulation,
are in fact surprisingly resilient to them. Early experience does not cause synapses
to form rapidly. Early enrichment
environments won't put our children on synaptic fast tracks. [3]
2.
...more synapses means more brainpower. [4] He responds thusly,
The neuroscientific evidence does not support this claim
either. The evidence shows that
synaptic numbers and densities followed an inverted-U pattern - low, high, and
low - over the life span. However,
our behavior, cognitive capacities, and intelligence - obviously - do not
follow an inverted-U pattern over our life span. Synaptic densities at birth and in early
adulthood are approximately the same, yet by any measure adults are more
intelligent, have more highly flexible behaviors, and learn more readily than
infants. Furthermore, early
adulthood, the period of rapid synaptic loss, follows the high plateau period
of synaptic densities from early childhood to puberty. Young adults do not become less
intelligent or less able to learn once they start to lose synapses. Furthermore, learning complex subjects
continues throughout life, with no apparent, appreciable change in synaptic
numbers. ... It is not true that more synapses mean more brain power. [5]
3.
"... the
plateau period of high synaptic density and high brain metabolism is the
optimal period for learning."
[6] He responds thusly,
We have not, and
probably have no way, to quantify learning and
knowledge. Claims
that peak learning periods, thus, depend more on one's intuitions than on
established scientific claims.
When educators say that the first decade of life is a unique time of
enormous information acquisition and that the brain is in its most sponge-like
phase of learning, they are making an intuitive conjecture not stating a
research result. Needless to say,
peoples' intuitions differ.
... We do not know
what relationship exists between high resting brain metabolism and learning,
any more than we know what relationship exists between high synaptic numbers
and ability to learn. Any such
claims are again conjecture correlating common sense behavioral observations
with a neuroscientific result in an attempt to understand what the brain is
doing. We can as readily make the
opposite conjecture ... [7]
He concludes thusly,
The neuroscience
and education argument attempts to link learning, particularly early childhood
learning, with what neuroscience has discovered about neural development and
synaptic change. Neuroscience has discovered a great deal about neurons and
synapses, but not nearly enough to guide educational practice in any meaningful
way. Currently, it is just too much
of a leap from what we know about changes in synapses to what goes on in a
classroom. Educators, like all
well-informed citizens, should be aware of what basic science can contribute to
our self-understanding and professional practice. However, educators should consider more
carefully what neuroscientists are saying before leaping on the brain and
education bandwagon. [8]
Dr Bruer
holds degrees in philosophy from the University of Wisconsin and University of
Oxford, receiving his PhD in philosophy from Rockefeller University. His works include Cognitive Science
in Medicine, The Inner Circle: Women in the Scientific Community,
and Schools for Thought: A Science of Learning
in the Classroom. As the
head of the James S McDonnell Foundation, he initiated a collaboration with the
Pew Charitable Trusts to establish the McDonnell-Pew Program in Cognitive
Neuroscience — "a new-mind brain science that links systems
neuroscience and psychology in the study of human cognition." Dr Bruer
lives in St Louis and can be reached at this email address.
In
Search Of … Brain-Based Education (Dr John Bruer,
Phi Delta Kappan, 1999)
_______________________
[1] Education and the Brain: A Bridge Too Far; Dr John Bruer, November, 1997. [Back]
[2] Put Brain Science on the Back Burner; Dr John Bruer. [Back]
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