Mystery deepens in memory research

Our memories are card-indexes consulted, and then put back in disorder by authorities whom we do not control.
- Cyril Connolly

In simple words, memory is the ability to remember information, experiences and people. However, like physical strength, memory can differ from person to person. Some people can remember facts and figures quite easily. There are others who tend to forget even the names of their friends. The mysterious quality of memory has drawn the attention of philosophers, psychologists and neuro-scientists. They have tried to explain the slow erosion of memory which occurs as we grow old. They also have come across people who could remember their childhood events very vividly.

Eminent philosopher Henri Bergson (1859 - 1941) came out with an intriguing theory when he said, “Memory is not a faculty of entering recollections in a register or putting them away in a drawer. There is no register, no drawer.” He believed that all memory is like the muscle memory that enables the body to recall how to ride a bicycle or to swim.

Henri Bergson: Memory is not a faculty of entering recollections in a register or putting them away in a drawer. There is no register, no drawer.

William James, who pondered the mysteries of memory as deeply as Bergson, said that we could develop our memory by forming diverse associations with every fact we care to retain. James tried a range of memory-training techniques and found them all a waste of time and energy. He said that instead of memory, attention could be trained.

Classification

The celebrated psychoanalyst Sigmund Freud felt that our memories and how they are arranged in our minds are vital parts of our personalities. He classified memory into many parts. Our conscious awareness is dominated by what we eat, hear, see or feel. The unconscious contains memories and experiences, but we are not aware of them. They lie deep in the unconscious and are difficult to access.

Despite such theories, we know that memory is a system necessary for storing knowledge. Psychologists say that there are three storage systems in memory: the sensory memory, short-term memory and long-term memory. By using our sensory memory, we can store information coming in through our senses in a split second. For instance, look at a rose and then close your eyes. You will see the rose in your mind!

The short-term memory (STM) stores information active in our consciousness. The news you read, your painful backache and everything pleasant or unpleasant you hear are stored in your STM. Psychologists say we can store seven items of information plus or minus two items. For instance, we can easily remember a telephone number having 10 digits. The duration of the STM is about 18 seconds. However, the time can be extended through rehearsal or constant repetition of the information we need to remember.

Information

The information stored in the long-term memory will remain there for a long time. When we repeat information stored in the STM, it automatically gets transferred to the long-term memory. According to psychologists, the long-term memory consists of episodic memory that retains our life experiences. The semantic memory retains factual information such as names, years and dates of important events. The procedural memory retains information on how to do things such as driving a car.

As most of us cannot remember everything we read, we have devised certain methods to remember important facts. A mnemonic is one such devise through which we take in a big chunk of information which can later be broken down into a phrase or sentence. A popular mnemonic in biology is “Kings play chess on fine green silla.” It stands for the way biologists classify different organisms on the earth: Kingdom, phylum, class, order, family, genus and species.

Sometimes, memory plays tricks on us. However much we go prepared for an examination, we fail to recall information when it is most needed. Although the information is stored in the long-term memory, we find it difficult to recall it. Psychologists say that this can be due to other information getting in the way, excitement or mental fatigue.

Intrinsic force

The well-known neuro-scientist Dr Erantha de Mel says, “Memory is the intrinsic force that binds our mental life, the thread that holds our personal history and that makes it possible to grow and evolve throughout life.” The magnitude of human memory capacity has never been a debatable issue, but most of us fail to recall information.

However, emotional memories appear to be an exception because they have a dominant impact on the mind. For instance, anyone affected by the tsunami will recall what happened on that fateful day vividly. According to Duke University researchers, amygdala, the brain’s emotional centre, interacts with memory-related brain regions during the creation of emotional memories.