There are three stages in human memory: sensory memory, short-term memory, and long-term memory.Sensory memory records what you see, hear, feel, taste and smell. In other words, it records the things that you “sense.” Sensory memory is quite short. Unless you transfer it into short-term memory, it disappears as soon as the experience is over. For example, consider seeing. We see hundreds of things during most waking minutes. However, unless your attention is captured by something you see, it is forgotten as soon as something else attracts your attention.Short-term memory lasts a little longer; in fact, as long as you pay attention to something, you can hold it in short-term memory. It might be a the telephone number that you have been repeating constantly till you can write it down, or the image of a flower. It will remain available in your memory as long as you actively think about it. If you stop paying attention to it, it will be erased within 10-20 seconds. In order to remember something after that, the brain has to transfer it to long-term memory. The process of rehearsing a phone number is, in fact, a way of passing the number from short-term to long-term memory.Like sensory memory, the amount of information you can keep in short-term memory is very limited. The general rule is that only five to nine items of information can be in short-term memory at once. This is the reason that short-term memory is so “short.” Each time you pay attention to a new piece of information that comes from sensory memory, you have to push out something that had your attention before. For example, if something interrupts your concentration on the telephone number before you rehearse it into long-term memory, it will get bumped out and you will have to look it up again!Generally, when we talk about memory, we have long-term memory in mind. Long-term memory can hold a virtually unlimited amount of information. Long-term memory contains perceptions and ideas that range from a few minutes old to the earliest weeks of life. Long­-term memory is like the huge hard disk of a giant computer where unlimited information can be stored for a lifetime. It is this memory that we build our ideas and experiences on, and hopefully bring it back to attention when we need it.If this sounds complicated – it is! Miraculously, our brains generally accomplish it without a hitch. With that background, we will explore a question: What is the difference between what you know and what you know how to do?Humans have two kinds of long-term memory: Declarative and Procedural. “Declarative” memory is the memory of ideas or events. “Procedural” memory is remembering how to do things. The words themselves help us remember which is which; “declarative memory” makes it possible to express something, or “declare.” “Procedural memory” helps us to do something – to “proceed.” Procedural memory is often not easy to discuss, or explain. However, even when we cannot explain how we do something, we can often use our memory of it without even consciously thinking about it. Procedural learning and recall are used in things like riding a bike, learning to touch type, learning to play a musical instrument or learning to swim. We can drive a car from place to place all day long without being aware of the driving process most of the time, and be completely safe. Once a “procedure” has been rehearsed mentally or practiced physically until it is firmly in long-term memory, it can be very long-lasting. For example, people often observe that you can still ride a bike many years after the last time you did it!Declarative memory comes in two flavors: “semantic memory” and “episodic memory.” Semantic memory is theoretical, or abstract, memory. It is independent of time and place. It is a piece of information. For example, knowing that an apple is called a “fruit” is a semantic memory. Knowing that two plus two equals four is also semantic memory. You can recall it, state it, you understand it, and you can use it to count things, but the formula does not represent anything real or specific.Episodic memory, on the other hand, is factual knowledge based on personal experience in a specific time and place. It is something that happened or something you sensed. For example, if you are thinking about looking over the Grand Canyon when you visited it as a child, you are experiencing an episodic memory. Another example: You can say, “When we were at the grocery store yesterday, John bought two apples and Mary bought two apples, so altogether we came home with four apples.” You are using semantic memory to apply a formula to four specific apples that you remember seeing, which is an episodic memory, or the memory of an “episode” in your life.These terms and concepts are important because the different types of memory are formed and stored by the brain in different ways and in different brain locations. They are subject to improvement or damage in different ways, as well. For example, not all kinds of memories are affected by aging in the same way, and aging is an important topic in the world today.Research is beginning to indicate that more and more people will live to 100 years of age.This can be good news or bad news, depending on the quality of life you expect and plan for during those later years. As you continue to study and learn about memory, remember these basic ideas can help you put your new knowledge and “memories” into context.Author: Robert McCluskeyArticle Source: EzineArticles.comProvided by: Bumper guardian