Issue 73 / January - February 2010
Memory and Forgetfulness
Adam forgot, so did his children.
How does our brain store information? How is it possible to make learning faster and easier? Is there any way not to forget what we have learned and to remember things more easily? Of what importance is the fact that information is never deleted from our memory, even if we have forgotten it? These are among many of the questions for which answers have been sought over the years.
Memory is one of the functions of the brain and it is defined as the ability to preserve acquired information consciously and relate it to the past. It is not just a certain portion of the brain, but rather the entire organ that functions in storing, processing, and retrieving external and internal signals. Signals that build up our memory are what we usually perceive through our five senses. When we burn our hand, or see or experience a traffic accident , when we are given a compliment and many other events are all examples of external signals, whereas internal signals are related to our nervous system or imagination. The pain one feels during a heart attack, the anxiety of a cold sweat, or a beautiful daydream are all stored in our memory too. We may or may not remember them. There is no deletion; it is simply that we do not remember. Forgetting is a state that is encoded in our makeup with differing degrees, depending on the kind of life the person has experienced. Age, gender, stress, habits, and illnesses all have varying roles in forgetting.
Short-term memory refers to saving and remembering what we have learned a few seconds or minutes ago; the prefrontal brain is the location for this temporary processing. Signals are kept in this portion of the brain for a few seconds and then conveyed to the back stage (as in the transfer of data from the cache memory to the main memory in computers). We tend to quickly forget those things on which we have not spent a long time or to which we have not assigned great importance, even though we can understand them. Imagine how unbearable our life would be if we were to store in our memories and remember things in infinite detail like the color of the wall we are facing, the variety of the objects around us and their qualities, the air we breathe in and out, or every beat of our heart. The signals that come to our brain within a certain time frame are filtered according to our needs and their significance and limitations are applied depending on their qualities and quantities.
There is no consolidation processing for short term memory. Second or minutes after signals are received they are retrieved in accordance with what we need; if they are insignificant for us, they are forgotten in the same amount of time. The information that is significant for the person is consolidated in the hippocampus and reserved in mid and long-term memory units.
Mid and long term memory
After being processed in the sub-cortex (limbic system) of the brain, signals are saved. Depending on their level of urgency, the meaning they stand for, and their emotional effect, signals are saved in either the mid or long term memory. Pain, joy, pleasure, and fear are states that solidify memory traces. A heart attack, the infliction of wounds and bruises or humiliation, accidents, visits from a loved one-these are all examples of events that are easily remembered. However, a lasting record is almost impossible to attain if the subject is something that has been forced (like a student studying for higher marks) or if the subject does not appeal at all. Consolidation is necessary to make a short term memory a lasting one. However, if a student is curious about the subject and enjoys what he or she is learning, then long term memory is possible without too much effort in consolidation. Forced consolidation (e.g. a studentâ€™s orientation to attain higher marks) requires a longer period. The information is consolidated more easily when a person is in a sound and alert state of mind.
Storage in the long-term memory does not occur immediately after something has been learned or experienced. For this storage to be possible at least an hour needs to pass to synthesize the memory proteins that are responsible for recording. If electric shock is applied to a personâ€™s brain immediately after an unforgettable event, they will not be able to remember the event. But if the electric shock is applied an hour later, the memory remains.
Once stored in long-term memory, information can be retrieved, even after months or years. When new information is obtained older information is called up and they are saved with a new pattern of storage, with the newcomers being related with the ones that have already been stored; it is in this way that long term memory is generated.
It has been argued that RNA has a role in storing old information. In experiments, guinea pigs were taught information through repeated practice which is stored in their long term memory. The brains of these animals were later minced up and fed to other animals. It was observed that those animals which had been fed the brains learned faster and more easily than other animals that had been fed on a diet that did not include the brains. This shows us that information encoded in the memory is not lost; rather it is transferred with the help of certain molecules. It is also known that DNA is related to genetic memory.
It has been found that people with good memories have a greater number of nerve cells and channels of transfer in the memory-related zones of their brains (cortex, corpus callosum, hippocampus, thalamus, hypothalamus, limbic system, amygdale, temporal lobe, and prefrontal cortex), while there are less cells in other zones of the brain. Nerve cells are stimulated while signals are stored in oneâ€™s memory. Even if a person has a weak memory, activities like reading, memorization, or other engagements that improve love, happiness, and peace of mind may help long-term memory.
It is important to find out whether forgetfulness occurs because of an illness or something else. Age is one major factor. Forgetfulness in an aging person is proportionate to the number of the loss of cells.
Stress, dealing with multiple things all at once, or occupying oneself with things that are of no benefit, that is, creating a pollution of information, all affect short term memory and may cause forgetfulness.
Forgetfulness due to damage or illness
If the nerve cells of the lower occipital lobe of the brain are damaged, old information cannot be retrieved. Likewise, in case of damage to the nerve cells that are found in the temporal lobes on the sides of the brain, or due to an insufficient intake of B3 and B12 vitamins, cerebral hemorrhage or an embolism in the veins of the memory zones forgetfulness may occur.
Patients with Alzheimer indicate short term memory loss. They tend to forget visitorsâ€™ names, daily events, or the doctorâ€™s advice.
Chronic alcohol abuse may cause damage in the hippocampus and thus in the ability to encode information.
Electroshock may also delete recent information that has been recorded in the short-term memory. Thyroid failure, Parkinsonâ€™s, hydrocephaly, schizophrenia, brain tumors, and epilepsy may also cause forgetfulness.
Spiritual teachings and religious services have many positive aspects in our lives in addition to being our duties for expressing our servanthood to God Almighty. In Islam, for instance, principles like â€śenjoining good and forbidding evil,â€ť praying at night, a brief afternoon nap, staying away from what is forbidden, reading and/or memorizing the Qurâ€™an, and other activities may provide some protection against forgetfulness.
It is also claimed that keeping oneself busy with things that are considered morally improper, not least things that are sexually provocative in an illegitimate way, may damage neurons that are operative in memory. In order to be less affected by forgetfulness in our advanced years, it can be helpful to read spiritually and intellectually useful material, to learn and memorize new words and concepts, to keep oneself in good moral condition by engaging in charity work and helping others, and to maintain good sleep and a healthy diet
On the other hand, thinking a bit more wisely, to be able to forget (not forgetfulness) also has many benefits. Our nervous system is relaxed by forgetting, otherwise it might collapse. Forgetting old informaÂ¬tion could well open up room for new information, although this does not mean that the information is deleted from memory; it is retrieved when needed. But, if forgetting reaches a level that is above medically exÂ¬pected averages, then medical help should be sought.
There are incidents of patients who are suffering from dementia and Alzheimer regaining their memory after electroshock therapy. Perhaps this is evidence that we will remember and testify for all our actions when we will have to account for them.