Notes on different kinds of Long-term Memory

If memory is a storehouse of information, what kind of information does it store? It stores a wide variety of information. After careful research, psychologists have tried to categorize LTM in distinct categories.

A comprehensive classification given by Tulving suggests that there are three types of long-term memory: (i) episodic memory, (ii) semantic memory, and (ii) procedural memory.

Episodic Memory

Episodic memory refers to the memories of the events that we have experienced personally. Since, this stores biographical details of our individual lives, it is also known as autobiographical memory. It allows us to move back in time so as to locate what was the event, and where and when the event took place.

Our childhood memories are episodic in nature. Which was your happiest birthday? When did you go to the movie the last time? What happened during the get together of your friends last year? These and many other similar experiences are contained in the episodic memory.

Episodic memory usually has an emotional content. When past personal experiences are recalled, the earlier events are experienced partly at the conscious level. The very pleasant or the very painful experiences are remembered better than the non-emotional events.

Episodic memory can be surprisingly detailed. It is also true that the episodic memory is prone to forgetting. Everyday, we experience innumerable events of which only some are important.

The unimportant ones are quickly forgotten. Extremely significant and emotional experiences are almost permanently stored in memory. In episodic memory, the events are recalled and experienced through a process of reconstruction. Every time the past experience is recalled, it gets more coherent and abridged. Sometimes the event gets distorted. Hence, episodic memory may not always be a reliable reproduction of earlier personal experiences.

Semantic Memory

Semantic memory is the sum total of our general abstract knowledge about the world. It stores the basic meanings of words and concepts, and the understanding of the formal rules to deduce other facts and solve problems. All that you would learn and store in your memory after reading this chapter is semantic memory.

It is somewhat like a mental dictionary of facts and principles. The semantic memory is hardly dependent on the time and place of the experience. Those who participate in television quiz shows have rich semantic memory. Semantic memory allows us to operate on events and situations that are not experienced directly through senses.

Procedural Memory

This memory system stores information regarding how things are done. It is sometimes referred to as non-declarative memory. On many occasions, we remember how a skilled action is performed, but fail to express it verbally. These experiences are stored in the procedural memory. This memory system refers to memories for skills and habits such as riding a bicycle or playing cricket.

It is primarily the result of basic learning processes. One can consciously recall the skill memories during the early phase of performance. With increasing practice, the skill becomes automatic. The experts perform advanced level skill without consciously recalling the appropriate skill memories. Procedural memory is important, because without it, we would not be able to retain many skills once they are learned.