FREE ESSAY ON COGNITIVE EFFECTS OF RADIATION

COGNITIVE EFFECTS OF RADIATION

Cognitive Effects of Radiation
There have been many terrible consequences of the Chernobyl accident, the worst of which
has been the suffering and death of millions of Ukrainian people due to radiation
exposure. The Physical deterioration of the residents exposed to high amounts of
radiation has been extensive and severe, with the rates of cancer and other diseases
shooting up by the hundreds of percents. Out of the 100,000 citizens relocated from the
Chernobyl plant and the city of Pypiat, Heart and Blood disease has gone up 938% from
.74/1000 to 6.94/1000, Endocrine, Digestive and Immunity disease has risen 1350% from
12.67/1000 to 171.11/1000, Respiratory disease has risen 577% from 23.67/1000 to
138.68/1000, and Nervous System disease has risen 500% from 21.25/1000 to 106.28/1000.
Other diseases, such as thyroid cancer and birth defects in children, have also risen in
sharp increments.
One of the most unexplored regions of radiation exposure has been the threat 
and consequence of cognitive decrements. There has been proven to be many negative
factors associated with exposure to radiation, such as fatigue, memory loss and memory
retention problems, concentration loss, lack of mental flexibility, stimulus response
problems, and recall difficulties. One test that has proven to be very useful in
assessing victims of radiation exposure for cognitive deficits is the Automated
Neuropsychological Assessment Matrices, or the ANAM. This test was created by F.W. Hegee,
the director of the Office of Military Performance Assessment Technology, and has proven
to be a very useful tool in cognitive assessment. It is a computer program that consists
of 27 subtests, and, unlike pencil and paper tests, stores the scores and converts them
to useable form right inside of the program without the complication and human error that
normally
accompanies the transmission of information from raw data to the form of useable data.
It is also portable, and can be saved to a disk to be used on any type of computer,
including a laptop, since it uses MSDOS as its operator. The best feature of the ANAM
though is the fact that not all of the 27 subtests have to be used when testing a
subject. The researcher can pick or choose which test he feels are the most pertinent to
what he is studying, such as Dr.Gamache did when studying the radiation victims of the
Chernobyl accident. He pulled only the tests he felt would be sensitive to cognitive
radiation damage, and in turn created his own cognitive assessment called the ANAM-UKR.
Out of all of the cognitive problems caused by radiation exposure, the most noticible and
frequently occurring are the problems associated with memory loss. Human memory works in
a straightforward and logical way, beginning with sensory memory, which lasts a few
seconds and is converted into short-term memory. Short-term memory has a retention margin
of approximately 5 pages worth of material, or 7 items of chunked material. Data will
remain in short term memory only a few minuets though, and must be rehearsed a few times
inside of the mind to eventually be transferred to long-term memory, where it is then
stored away. People with radiation poisoning have shown to have problems in the
transition of information from both sensory to short-term memory and short term to
long-term memory. This is shown by the Matching to Sample test, which tests short term
memory recall, Running Memory, which tests Sensory to Short Term, and Digit Span, which
tests Sensory to short term, recall, and chunking abilities. Code Substitution is also
used to test short term and long term memory, as it is given again both a few minutes
after and 45 minuets after the original test. It is not yet known what part of the brain
is malfunctioning to cause these memory problems, because as
has been proven with memory loss associated with Alzheimer's, epilepsy, and Korsakoff's
syndrome, many different parts of the brain can be associated with memory loss. 
Mental flexibility is also a problem with people who have been exposed to large doses of
radiation. They have a difficult time with spatial rotation, which is the ability to
imagine an object in your mind and turn it around to different angles and degrees. If
shown two objects, one being a symbol and the other being the symbol at a 90-degree
angle, a person with radiation exposure would have a more troublesome time than a normal
person in recognizing it as a matching symbol. It has also been found through testing
that rotating an object and reversing an object as a mirror does can produce different
results, showing that both tests activate different structural areas of the brain. Word
associations, or what can be considered stream of consciousness, is also a function of
mental flexibility, and has shown to be impaired in people exposed to large doses of
radiation. When asked to link a word, such as car, to something else, they often take
longer than the control group to find an associated word, such as street, if they come up
with anything at all. 
Loss of concentration and high confusability are also symptoms associated with radiation
exposure, yet it is still uncertain whether or not this is caused directly from the
exposure to radioactive substances, or if it is a symptom of the high rate of
fatigueability that is shown to be common in victims of radiation. On the Stanford Sleep
Scale, a test created to determine the exhaustion level of patients undergoing mental
testing, radiation victims have, on the average, shown a drop of at least1 level after
being tested for a period of 45 minutes, a fatigue rate that is much higher than normal.
Their loss of concentration and mental confusion has also been demonstrated by the
Running Memory test, which repeats a series of sixty letters, and asks the respondent to
identify whether or not the previous letter is the same as the one being presently shown.
People who have been exposed to radiation, depending upon the dosage received, often have
trouble performing this task, and quickly become confused.
These decrements in cognition, as with most other forms of brain damage, show no sign of
getting any better, and research has shown that in the years since radiation exposure,
lapses in mental ability tend to continue getting worse. The situation in the Ukraine is
even more severe since the victims of radiation, who have no choice but to continue
living in the Ukraine, are exposed every day to new levels of radiation that contaminate
the food they eat, they water they drink, and the wood they use in the construction of
their houses. Until a cure can be found for the effects of radiation on the body, those
who live in the Ukraine will continue to grow sicker not only in physical aspects, but in
Cognitive as well.