How do we lose our Memory?

            You must have seen numerous movies in which a person loses his/her memory after an accident or on hearing tragic news. Such people forget their past and even fail to recognize their close friends and relatives. So much so, they even forget their own names. These incidents happen in real life, too, and in psychology, this condition is called amnesia.

Loss of Memory is a Psychological condition

            Amnesia can be caused by a number of factors, like a severe head injury, mental shock, extreme tiredness, and ill effects of medicines, surgery of brain, psychological processes, and old age and may even be due to drinking alcohol. Whatever may be the cause of amnesia, their effect on the brain is mostly the same in each case.

            Memory is said to be stored in the brain as a memory trace. What this trace is made of is still unknown. According to one theory, each experience sets up an oscillating pattern or wave of electrical excitation in groups of cells.

            Each learning experience generates its own pattern of excitation. It is amazing that though a given neuron may participate in thousands of separate memories, yet its removal will not noticeably reduce any of them.

            Memory is considered a three-part system- sensory information store SIS, short term memory STM and long term memory LTM. The SIS forms an instant, but very temporary storage of every piece of information that comes in. information can last for only about three tenths of a second in the SIS. If it has not been selected and transferred to short term memory within this time, it fades away.

            Short term memory is used for carrying information for a few seconds only. Two characteristics of short term memory prevent its use as permanent information store. First, concentration is required to maintain a particular piece of information in it. Second, it is able to store only seven or eight items such as an eight-digit telephone number.

            For any information to be permanently stored, it has to be passed form short term to long term memory by the mechanism of rehearsal. The long term memory has unlimited capacity. It allows a person to remember events that happened years before. Permanent memory takes place through structural changes in nerve cells caused by pattern of electrical activity in these cells.

            When somebody suffers form amnesia, he forgets event either preceding it or following it. It can last for weeks, months or even years. There are people who have lost their memory for the rest of their lives. When memory is restored, one remembers all the forgotten things but forgets every event, which took place during the period of amnesia.

            One thing is however certain in spit of restoration of memory; some after effects do remain, thereby weakening the memory.

What is Memory?

        Different people have different memory spans. Have you ever wondered why some people can remember things that look place five years ago, while others can’t remember an incident that took place a year back? This is due to the difference in memory span.

Human Brain and Functions

            Memory can be defined as the capacity to keep information available for later use. The process of memory can be divided into four aspects- learning, retention, forgetting and retrieval.

            The initial storage of information is called learning keeping the new information available is called retention the loss of old information over a period of time is called forgetting and utilization of stored information is called retrieval.

            According to psychologists there are four kinds of learning. Classical conditioning is the simplest kind of learning. Ivan Pavlov studied it during the early 1900s. He offered a dog food and at the same time rang a bell. The sight of food made the dogs mouth watered. Pavlov called this an unconditioned response because it was not learned. Soon however ringing the bell was enough to cause the dog mouth to water. This was called conditioned response. Classical conditioning is often called respondent learning.

            Another form of learning is called instrumental. Often a person learns to do something as a result of what happens after the person does it.

            Multiple response learning is the third type and it takes place when a skill is learnt. A sequence of simple things must first be learned. Using a typewriter is a kind of multiple response learning. At first a person has person learns to type word by word or phrase by phrase.

            The fourth type of learning is insight learning. It means solving a problem through understanding how the different parts of a problem fit together. A simple example is that of a young child wanting to climb on the top of a table. The child may use a stool to get onto the chair and then use the chair to climb onto the table.

            There are two basic theories to explain the process of memorizing events. According to one theory memory is said to be stored in the bring as a memory trace. When we learn or experience something impulse are generated I the nerves of the brain.

            These impulses impart their effects I the brain in the form of a record. According to the other theory sensations by learning produce some permanent changes in the brain which remain there in the form of memory.

            According to some biologists the RNA present in the brain keeps the record of events. It has been observed that the quantity of RNA present in the brain keeps on increasing from the age of there to the age of forty. During these years the memory of the man also increases.

            The quantity of RNA is almost constant from the age of 40 to 55 or 60. Therefore a mans memory is almost constant during this period. After the age of 60 the quantity of RNA starts decreasing and so does the memory.

             The only effective way of remembering things is to repent them many times. Interest is every important. Boring things are much more difficult to remember than something that we understand and are interested in. motivation or desire to do something is also important.