| This
was in response to the April 3 1997, issue of Nature which has an
article by Bruce McEwen of Rockefeller University. The article states,
"...significantly more new neurons exist in the dentate gyrus
of mice exposed to an enriched environment compared with littermates
housed in standard cages." The Nature article suggests that
this is biological confirmation of the importance of education and
contradicts the previous dogma that the number of active brains
cells is essentially fixed early in life. Similar tests were performed
in the 1970s by psychologist William Greenough at the University
of Illinois and they reached this same conclusion.
Roger
Penrose in his book The Emperor's New Mind describes the
relevance of synaptic firing in the phenomenon of brain plasticity.
He states, "It is actually not legitimate to regard the brain
as simply a fixed collection of wired-up neurons. The interconnections
between neurons are not in fact fixed but are changing all the time.
I am referring to the synaptic junctions where the communication
between different neurons actually takes place. Often these occur
at places called dendrite spines, which are tiny protuberances on
dendrites at which contact with synaptic knobs can be made. Here
, 'contact' means not just touching, but leaving a narrow gap (synaptic
cleft) of just the right distance - about one forty-thousandth of
a millimeter. Now under certain conditions, these dendrite spines
can shrink away and break contact, or they (or new ones) can grow
to make new contact."
It
is estimated the you have about one hundred billion neurons in your
brain, about ten billion of which are in your neo-cortex. It has
been speculated that you lose about one thousand neurons each day
after you reach forty. Research is finding that this loss can be
offset by stimulating the brain regularly. A nerve is not like a
simple relay circuit. Whether it fires or not depends on a complex
interplay of many inputs. These can be inhibitory or exhibitory
influences from the neurons surrounding it, or the intracellular
fluid that fills the synaptic gap. If a neuron doesn't get enough
excitatory input from the neurons connected to it, or gets too many
neurotransmitters that inhibit neural action, it will do nothing.
Other
research has found that if a neuron is being used, it secretes substances
that affect nearby cells responsible for the neuron's nourishment.
These cells, in turn, produce a chemical that appears to preserve
the neuron from destruction. If the neuron does not get that substances,
it dies.
In
concert with this effect, Leif Finkel and Gerald M. Edelman of Rockefeller
University have discovered that neurons do not act randomly but
as a network. They tend to organize themselves into groups and specialize
for different kinds of information processing. For example, when
a touch stimuli comes in from the finger it first comes into the
neural network. The information activates some groups of neurons
more than others, and this high level of activity causes the connections
among the group of excited neurons to be reinforced. As more and
more similar patterns come through the network, the connections
among the activated group of neurons becomes stronger and stronger,
and eventually the group becomes specialized for processing that
one finger's sense of touch.
As
far back as 1949 Canadian neurophysiologist Donald Hebb proposed
in his work Organization of Behavior that, "When an
axon of cell A is near enough to excite a cell B, and repeatedly
or persistently takes part in firing it, some growth process or
metabolic change takes place in one or both cells such that A's
efficiency as one of the cells firing B is increased." In other
words, if one neuron sends a lot of signals that excite another
neuron, the synapse between the two neurons is strengthened. The
more active the two neurons are, the stronger the connection between
them grows; thus, with every new experience, your brain slightly
rewires its physical structure.
In
working with nerve tissue scientists have also found that if two
connected neurons are stimulated at the same time, the amount of
signal passing from one neuron to the other can double. This is
known as long-term potentiation or LTP. Whether this is permanent
or not has yet to be verified. But work with aplysia, a sea-slug,
by Eric Kandel of Columbia University, verified that the animal's
neurons grew stronger as it learned to associate a food it disliked
with the presence of a beam of light.
The
internet is replete with more information on neural networks and
brain plasticity. A simple search engine inquiry into either of
these subjects will give more detailed information and lead to specific
scientific articles.
This
purpose of this site is to provide a simple method to 'exercise'
the brain daily and make new connections. The brain's plasticity
is becoming more apparent in cognitive science. More and more evidence
is surfacing to validate the idea of "use it or lose it."
Though this is something that common sense might dictate, there
are very few mechanisms created that will allow us to use our brains
in unfamiliar ways each day. Doing different puzzles will produce
different kinds of thought processes as you search for solutions.
Puzzles are useful because they do have solutions, therefore you
can test your ability to find a resolve because there is one.
The
ability to flex the mind in whatever direction is necessary to find
resolve is what leads to true creative thinking. Creativity is not
just coming up with something that is different, but with something
that is coherent, useful and relevant to whatever stimulated the
need for a creative thought. Learning to think creatively is a skill
that anyone can learn. Test yourself and see how flexible your mind
is. Try this method for six months and see if you are able to think
more clearly and apply either logical or analogical thought at will
to any situation that arises. |