Educational Psychology—Limitations and Possibilities

Neuropolitics 613
This land of infinite possibilities is only the beginning of the neuro-odyssey into the brain.
Given these possibilities for connections each brain is unique with different neural connections
shaping each brain differently even for identical twins who might experience the same things
throughout their lives. There should be little wonder why the brain has remained a mystery for
centuries. How could anyone draw generalizations about the brain when every brain is different
in terms of neural networks and synaptic connections? To make the understanding of the potential
connections more daunting is the reality that the brain is always active, losing neurons here and
making new connections there.
These staggering numbers have not stopped neuroscientists from understanding the brain
because like so many other fields in science, neuroscience has benefited greatly from the development
of computers. Specifically, neuroscientists have learned to utilize parallel processing
computers to understand the brain. Whereas Descartes, Leibniz and other early speculators of the
mind and brain did not have the benefit of computers, neuroscientists do, and they are using it to
their advantage to advance numerous theories about the brain.
The use of parallel computers is called Parallel Distribution Processing. It works from the
assumption that the brain with its one hundred trillion synaptic connections has different layers
of neuron networks with each neuron and its synaptic connection aiding in a function of the brain.
For example, the neuro-philosopher Paul Churchland points out that humans have only four taste
receptors in their mouth. Yet, of course, there are more than four types of tastes. Our taste receptors
overcome this simple problem by having different levels of activation for each kind of taste. As
Churchland points out if there were only ten activation levels on our four receptors that would still
mean we could distinguish between 10,000 different kinds of tastes. We remember these tastes
by moving through different layers of neurons creating different paths within the brain in which
each neuron in the path represents a small part of the experience and remembrance of taste. Like
a parallel processing computer, if we were to lose a few of the neurons within our connections to
recognize say the taste of a lemon, we would not lose that ability to recognize a lemon nor would
we have to relearn the taste of a lemon each time we tasted one. The same holds for parallel computers.
If there is a glitch in one or two areas of a program, a parallel computer would not lose its
ability to process a program. It would only find a new way around the program error. Given that the
brain works on a parallel distribution process, it is able to continue to function with a loss of 10 percent
of its neurons without major damage to our ability to function. This does not mean that the
brain’s ability to function on a parallel distribution basis prevents any permanent loss of function.
When the brain loses too many of the neuron layers as a result of a lesion that disrupts the normal
network pathways we lose that function and the result can be major long-term brain dysfunction.
This ability to create neuron patterns permits neuroscientists to speculate how the brain creates
its own concepts and categories to remember and house different experiences such as specific
tastes, the recognition of faces, or the recognition of similar words. Humans are able to remember
different tastes, faces, or words because the neuron pathways not only work in a forward moving
motion from the world to the sensory-motor apparatuses of our bodies to the numerous neuron
layers within our brain, they also work backward. This ability is called feedbackward or recurrent
pathways. Recurrent pathways permit the brain to remember experiences such as tastes, faces, or
words that are similar and the brain is able to construct prototypes or categories in which similar
experiences or concepts can be placed, remembered, and stored until they are needed the next
time the brain experiences the taste of a lemon, sees a familiar face, or reads/hears a new word.
This ability to create and maintain recurrent pathways permit the brain to work in an efficient
manner so it need not create new neural pathways each time it comes upon something that is
similar but slightly different from something else.
If this was all that neuroscientists knew about the brain it would not be much. The key to this
theory about neural pathways is the ability to know what part of the brain is activated when say the