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Sunday, June 23, 2013

Brain plasticity or growth

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.

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