The Three Memory Systems Sensory Long Term

The Three Memory Systems: Sensory, Long Term And Short Term Memory, Essay, Research Paper Abstract In this paper, I emphasize there is no such thing as a “bad” memory. Then I show the reader reasons for this explanation. First, I will discuss the three categories of memory: sensory, short term and long term memory.

The Three Memory Systems: Sensory, Long Term And Short Term Memory, Essay, Research Paper


In this paper, I emphasize there is no such thing as a “bad” memory. Then I show the reader reasons for this explanation. First, I will discuss the three categories of memory: sensory, short term and long term memory. Then an overview of their characteristics and downfalls. Second, I talk about forgetting and the positive and negative aspects of it. Afterwards, I go into the measures of forgetting and the many theories that follow forgetting. I will also discuss two common diseases that involve memory in which I call “The Forgetting Diseases”. Last I briefly talk about the five principles of remembering. All of these aspects of memory show what a memory cannot exist as a thing.


The Three Stages of Memory

The human mind has the ability to learn many things, but learning would be impossible without memory. Without it we would respond to every situation as if we have never experienced it. There are many misconceptions of memory. One of which is that many people believe they either have a “good” or a “bad” (e.g., cannot remember things well) memory as if it were a thing (e.g., object). The word memory is merely an abstraction that refers to a process (or many processes) rather than a structure (Higbee, 1996, p. 2). Memory is divided onto three sub categories: sensory, long term and short term memory. Later, I will discuss these three categories in detail.

Memory depends on three consecutive stages: encoding, storage, and retrieval. Encoding is learning the information and forming a memory file. Storage is placing this memory file into a compartment such as long term memory. Lastly, retrieval recovers the memory file from where it was stored. These stages can be compared to a filing cabinet. First, information is typed on a piece of paper. Then it is placed in the filing cabinet under the correct category. Last, when the file is needed again one would retrieve it. The information will not process, if we fail to achieve one or all of these stages. We would assume we have forgotten the information. My second chapter will discuss why and how we forget. I will review two common diseases: Alzheimer’s and amnesia. Then I will talk about the five principles of remembering.

Three Memory Systems

Sensory Memory

Weiten explains sensory memory preserves information in its original sensory form for a brief time (1998, p. 266). This “brief time” lasts for a fraction of a second. There is at least two components to sensory memory or iconic memory. First, the retina in the eye is influenced by the brightness of a stimulus. The second one involves shape recognition. It occurs in the brain after the information from the two eyes have been integrated.

Hearing also contributes to iconic memory. An example would be locating an object in a room. Although we do not think of this as memory, it involves storing and retrieving information. We often remember things when they are spoken rather then written. This is called echoic memory since it is like an echo in our mind after the word has spoken. Sensory memory is not important to the overall memory system because it is also deals with perception.

Short Term Memory

Short term memory is a name given to the system or, perhaps more appropriately, set of systems which allow this temporary storage of information which is essential for a brief period of time (Baddeley, 1982, p. 14). Short term memory, also called working memory, relies on attention and rehearsal. The retrieval process is automatic. It is an active and ongoing process that is easily disrupted. A person can only pay attention to one thing at a time and is easily distracted. Rehearsal is repeating information continually orally or mentally. Rehearsal helps keep information in short term. If the information is rehearsed often it can transfer into long term memory. George Miller discovered short term memory has a limited capacity that is an average of seven items. New information quickly replaces the old information. Working memory stores unrehearsed information for 30 to 20 seconds.

Chunking increases the limited capacity of short term memory. It places separate pieces of information into larger chunks. Chunking is usually used with numbers and letters. For example, phone numbers are grouped into three chunks. This helps us remember phone numbers better.

Baddeley discovered working memory consists of three components. The first is the rehearsal loop. As I discussed earlier, it involves rehearsal to memorize information. This enables us to remember sequences, letters and words. The second component is visuospatial sketchpad that receives and codes data into visual images. The last component is executive control system. It handles the limited information that people can juggle at one time as they engage in reasoning and decision making (Weiten, 1998, p. 269). This helps with reasoning and mental arithmetic.

Although short term memory has many disadvantages, it also has many advantages. Such as it helps filter unnecessary information so our minds are not cluttered. Working memory holds goals and plans that we are following and helps us achieve those goals at the moment. Short term memory can be compared to a central processing unit (CPU). It receives information, stores it, retrieves it, performs calculations and stores the answer, displays it or prints the answer out. Short term memory handles many functions and depends on more complicated processes.

Long Term Memory

To an experimental psychologist the phrase ‘long-term memory’ refers to information that is stored sufficiently durably to be accessible over a period of anything more then a few seconds (Baddeley, 1982, 9.12). Long term memory has an unlimited capacity and information can be stored permanently. Long term memory can involve flashbulb memories, which are vivid and realistic memories. The memories stored in our long term file are usually the most meaningful memories.

There are three types of long term memory; procedural, semantic, and episodic memory. Procedural memory is remembering how to do something. An example would be remembering how to use the quadratic formula. Semantic include recalling the factual information but it excludes the time and the place. Episodic memory involves those memories that are personally meaningful.

Long term memory organizes information so the retrieval process is easier. One of these organizations is clustering. Clustering is grouping information into a specific category. One can organize information into many levels based on common properties called conceptual hierarchy.


Many people believe forgetting is evil and we should avoid it as much as possible but forgetting can help us remember the important information It remembers the important information while disregarding the unimportant information. The problem (with forgetting) is that the mechanism of memory works independent is conscious thought (Kellett, 1980, p.113). Forgetting is caused by failures in the encoding, storage and retrieval processes that I discussed earlier.

Measures of Forgetting

There are three main ways to memorize forgetting. To measure forgetting one most measure the information revived. One of which is recall which is when one produces information without any clues. An example of recall is an essay test. Sometimes we cannot recall something without a clue that is called aided recall. A person may not remember something without clues but it can be measured by how familiar the information is. This is called recognition that means to know or be aware of something perceived. An example of recognition would be multiple choice and matching tests. This measurement is usually easier. The last measurement of forgetting is relearning or savings. This is measuring how long it takes one to learn something the second time. If they learn it quicker the second time then there is savings in learning time. Another way relearning can be measured is how many trials it takes until the information is memorized.

Why do we forget?

There are many theories that explain why we forget. One of which is decay which focuses on the storage of memory. This theory proposes memory traces fade with time. The crucial factor of this theory is the elapse of time. The longer there is a delay, the greater one may forget the information. This theory contributes to sensory and short term memory.

Repression is a term used by psychoanalysts to denote the unconscious process by which the mind selectively blocks certain events or thoughts from being available to recall (Kellett, 1981, p.158). Freud proposed this theory that is also called motivated forgetting. The ‘events’ repressed are usually guilt or fear associated with sexual abuse. Freud believed motivated forgetting started in early childhood. This theory brings up a lot of controversy. Most psychologists do not accept this theory because repressed memories often turn into false memories.

We often fit our memories into how we want to remember them rather then how they really were. This is known as distortion theory. The next theory is interference that proposes most forgetting is due to other learning. There are two types of interference; proactive inhibition and retroactive inhibition. Proactive inhibition refers to information one learns in the past, may interfere with something learned recently. Retroactive inhibition is the opposite in which information learned recently is interfered with information learned in the past.

This next theory attributes to failure in encoding. If one can not remember the information learned in the first place then it cannot be retrieved. This is called pseudo forgetting that means is based on a lack of attention. Lastly, we forget due to a failure in retrieval. People remember something that they could not earlier. An example of this is the tip-of-the-tongue phenomenon, which is when one cannot completely grasp something they are trying to recall. All of these theories work together to explain forgetting.

Forgetting Diseases

A disease that is becoming more common is Alzheimer’s disease, which is not a condition of aging. The first stage symptom for the disease is memory loss, disorientation and inability to make good decisions. The first stage lasts two to four years. The second stage is called moderate Alzheimer’s which can last from two to ten years. Memory loss becomes more severe and the patient might have difficulty recognizing relatives. The third stage lasts from a year to three years. This patient cannot speak logical sentences and this stage may lead to death.

It is unknown what causes Alzheimer’s disease but there are some ideas. Researchers found a low amount of neurotransmitters called acetylcholine in the brains’ of Alzheimer’s patients. Autopsies show tangles in part of the brain. This seemed to have greatly reduced the number of neurons and possibly their ability to pass electrical and chemical signals, which is how neurons store and retrieve information (Kurland & Lupoff, 1999, p.81).

This disease is not totally understood; therefore there are few treatments. There are drugs that slow down the disease. Another drug, tacrine, increases the amount of acetylcholine. It improves the mental functions of the patient but does not stop the progression of the drug.

Amnesia is another common disease that involves forgetting. There are many types of amnesia; localized, selective, generalized and continuous. Localized amnesia involves forgetting specific features of a trauma. Selective is the failure to recall specific events, such as a death of a loved one. Generalized is the inability to recall one’s events up to surrounding time of a traumatic experience. Continuous amnesia is the failure to recall events around the traumatic events and into the past. Generalize and continuous occur less frequently.


Everyone can recall a childhood memory, whether it is falling off their first bike ride or even running around in their diapers. To remember these things we must correctly store them. Throughout my essay, I briefly discussed remembering. This part of our memory is essential towards our lives. The basic principles of memory are based on meaningfulness, organization, association, visualization and attention.

The Five Principles of Remembering

First, it depends on how meaningful the information we wish to remember. It makes learning the information much easier. Most of our childhood memories hold some meaning to them. People often use rote memory learn information. Rote memory is when one repeats information over and over without making it meaningful. This does not guarantee learning. Words that refer to concrete objects of which the memorizer can form a visual image are on the whole more easily remembered than abstract word for which imagery is difficult (Baddeley, 1982, p.32). Meaningfulness goes hand in hand with association and visualization. If someone is familiar with the subject they are learning, it will be easier for them to learn it. There are also rhymes that we use to help us remember information. A common childhood rhyme is “i before e except after c”.

Second, organization plays a big part in our memories. If someone is looking up a word in a dictionary they would automatically begin with the first letter of the word. If the dictionary was not in alphabetic order it would be difficult to find the words we are looking for. Our minds work the same way. Once we learn the information, we should organize it immediately so it is easier to retrieve. To do this one must categorize the information into similar categories. Organization also plays in a role of how we learn one thing faster than other things. For example, depending on how the words are organized, in a list of words, depends on how easy they are to memorize. This is called the serial position effect. Items at the beginning and end of the list are easier to remember. Organization plays the biggest role in remembering information.

Next, association refers to relating what one wants to learn with something they already know. This idea goes back to the meaningful value of the information. We associate information we can relate to. Relating to the information helps retrieve it quicker. The more one knows about a subject the more one can associate new facts. Association can occur on an unconscious level but only to a certain degree.

Memory is more visual then verbal. Visual imagery is effective with verbal material as well as pictures. Two possible reasons are suggested: First, images are inherently more memorable than words; second, words that evoke images are coded dually (in both verbal and visual memory) so that there is twice as great a likelihood of remembering them (Higbee, 1996, p. 57). Visualization of verbal material means picturing an object or idea that relates to the information.

You are standing in the middle of a parking lot searching for your car. Thinking; did I park in the green section or the yellow section? Finally, you spot it in the red section. This happens to almost everyone. We just never learned where we parked to begin with. If we do not store the information in the first place, we will not be able to retrieve it. Attention is the key to remembering anything. We have to pay attention to something we wish to remember in the future. As I mentioned earlier, we can only pay attention to one thing at a time. This might be the last section in remembering but it is not the least.


Today everyone is interested in learning ways to improve their “bad” memory. As I discussed earlier, there is no such thing. In fact we create these “bad” memories through our learning techniques. Since today’s society has a fast pace, we do not have time to learn the information correctly. I discussed the many aspects of memory that contribute to our learning.

The three memory systems play a big role in this. There are positive aspects and pitfalls that take place throughout these memory systems. We need to be aware of these aspects while learning. Then I discussed forgetting which most people view as an unpleasant thing but in the end it helps us disregard the useless information There are many theories that go along with forgetting. Although most theories are widely accepted each one plays a part in our forgetting. I decided to pick two common diseases that go along with memory: Alzheimer’s and amnesia. Even these examples show that memory cannot be catergoized as a thing. Scientists have not discovered an exact place in the brain in which remembering occurs. Then I briefly went over the five principles of remembering. The most important way to improve one’s memory is to pay attention to what one wants to learn. In the end, no one has a “bad” memory. It is within ourselves to improve our learning techniques.



Hilgbee, K. L. (1996) . Your memory: How it works and how to improve it. New York: Marlowe and Company.

Weiten, W. (1998) . Psychology: Themes and variations. New York: Brooks/Cole Publishing Company.

Baddely, A. (1982) . Your memory: A user’s guide. New York: Macmillan Publishing Co., Inc.

Kellet, M. (1980) . Memory power. New York: Sterling Publish Co., Inc.

Kurlan, M., & Lupoff, R. A. (1999). The complete idiot’s guide to: Improving your memory. New York: Macmillan Publishing Co., Inc.