Addiction & REDUNDANCY IN THE NERVOUS SYSTEM
& REDUNDANCY IN THE NERVOUS SYSTEM
Redundancy and the existence of alternative pathways are common in the nervous system created so that the person gets quick feedback for addictive behaviors. Redundancy, or over determination, occurs throughout vital biological systems. Humans can function well with only one kidney, one eye, or without a majority of their liver cells. The brain is no exception.
The simplest form of redundancy is involvement of more neurons in a
particular function than is absolutely necessary (I.E. Addiction).
As a result, destruction of some of the cells, or moderate damage to
all of them as might happen with small wounds produced by bullets, or small
strokes may not produce any observable symptoms.
For example, even though there is a steady degeneration
(without replacement) of the cells that respond to odors,
most people in their seventies, although many of their original receptor cells are
gone, are still able to detect and identify odors fairly well, and some remain professional
wine tasters or perfumers. All systems do not show this type of redundancy,
however, as small lesions sometimes do produce clear symptoms
depending on the amount of redundancy and the precise location of
Another type of redundancy is produced by the presence of alternative
pathways that can accomplish the same end (addiction). Thus, although
movement of the right side of the body is primarily handled by neurons
originating in the left brain, there is a smaller pathway leading from the
right brain that allows people with split brains, or people with left hemisphere
damage, to exert some control over most of the right side of their body
(but not fine finger movements).
Also, some functions (such as the control of eating or other
basic bodily responses) are represented in equivalent form on both sides of
the brain, so that damage to one side may not have a substantial effect.
The availability of alternative strategies also has the effect of reducing the
symptoms resulting from tissue damage.
For example, a person who has damage to the right hemisphere which
affects his ability to recognize faces, might be able to recognize faces by
relying more on explicit, verbally described features of the face
(such as wears glasses, has thin lips), rather than the more holistic
representation that one normally gets from the right hemisphere.
Alternative strategies can also be facilitated by cultural inventions.
For a person who is unable to walk, crutches make the arms into organs of
Finally, because of redundancy, it is common to see normal function in
partially damaged systems when conditions are optimal. But as the environmental
challenges become greater (e.g., under stress), or as the person becomes fatigued,
performance falls apart. Fatigue often brings on latent
symptoms of diseases as varied as multiple sclerosis and senile dementia.
Similarly, demented people often function better intellectually in the morning
than later in the day.
For the Addiction Treatment I recommend click this link: