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. 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.
