THE CONCEPT OF MEMORY

Memory can be defined as the process by which people encode, store and retrieve information. There are three stages in information processing; (encoding, storing and retrieval represents the process) somewhat operating like the way the computer operates. A simple diagram will help us understand the process.

INPUT ► ENCODING ► STORAGE ►RETRIEVAL

Input into memory

(Initial recording of information) (Saved or held in memory for future use) recovery of stored information

1. The first memory process is encoding: the transforming of information so that the nervous system can process it. Encoding is the process whereby information is thought to be put in memory.

Basically you use your senses, i.e. hearing, sight, touch, taste, temperature, and others to encode and establish a memory. You use acoustic codes when you try to remember something by saying it out loud, or to yourself, repeatedly. For example, in trying to remember the notes that make up the spaces in the treble clef of a musical measure, you would repeat the letters “F,” “A,” “C,” and “E.”

When you attempt to keep a mental picture of the letters, you are using visual codes. Another way you might try to remember the notes is by using semantic codes. In this way, you try to remember the letters by making sense of them. For example, if you wanted to remember the letters “F,” “A,” “C,” “E,” you might remember the word face. In this way, you have to remember only the word rather than the individual letters.

2. After information is encoded, it goes through the second memory process, storage. This is the process by which information is maintained over time. How much information is stored depends on how much effort was put into encoding the information and its importance. Information can be stored for a few seconds or for much longer. Storage is the maintenance of material saved in the memory system. It relates to the methods assumed to be involved in the retention of information. If the material is not stored properly, it cannot be recalled later.

3. The third memory process, retrieval, occurs when information is brought to mind from storage. The ease in which information can be retrieved depends on how efficiently it was encoded and stored (as well as on other factors, such as genetic background). Retrieval is a recovery process through which material stored in memory is brought into awareness and utilised. It is the process of recovering information from memory. This term is synonymously used with recall and remembering. There are three ways in which we recover information. These are recall, recognition and relearning.

Recall: This depends upon active remembering of performances learned previously e.g. poem, routines thus exam questions require recall- we dig from memories.

Recognition This is where we are given a clue or shown on formation from which we can remember something learned previously.

Relearning When something occurs after a lapse of time.

Note: Memory consists of learning, retaining and remembering what was previously learned.

LEARNING AND MEMORY

Memory is a term used to describe the activities of acquiring, retaining and recalling knowledge. Memory aids learning in that for one to be regarded to have learned, he or she should be able to retain and retrieve the stored information at the time it will be required. Memory is therefore a bank for learned information. Children who fail to tell what they have learned or fail to remember are said not to have learned.

So far we have looked at some of the concepts and terms associated with memory as well as the definition of memory, let us now describe the three main types of memory.

Types of memory and techniques to enhance memory

Types of Memory

Like we have types of different things on earth, there are also different types of memory, each performing its own functions.

There are three kinds of memory storage systems. These types of store-houses vary in terms of their functions and length of time information is retained (Atkinson and Shiffrin 1971). The following are the types;

a. Sensory Memory (Register)- this is retrieval of information by the various sense organs.

(i) Iconic memory– ability of the eye to retain visual information after it has been presented.

(ii) Echoic memory-refers to the ability of the ear to retain information after it has been presented.

(iii) Semantic memory– refers to how we store our knowledge of the world around us by encoding meanings not simply hard facts e.g. capital city of Zambia. Data source (Roger Davies $Peter Houghton (1995)

The information in the sensory memory register remains there for only a fraction of a second. Examples could be:

· Faces of people in the street, you do not remember them unless something special happens.

· Hearing the sound of a twig snapping or a flash of lightening.

Could you think of other examples in our everyday life of how information is stored in the sensory memory register?

b. Short Term Memory (STM)

The major function of the short term memory (STM) is to hold information long enough for processing. It holds information for 15 to 20 seconds. The STM enables you to grasp the meaning of a sentence even while you forget its precise words. It is designed to deal with information in the active state and at the conscious level. It is also called ‘operational memory’ because it retains information called up for the more permanent long-term store.

Buddley and Wilson (1985) described the STM as the working memory because it is the system in which decisions are made, problems solved and information is directed.

Information in STM is quickly lost unless placed through rehearsal and encoding in more permanent store. STM has limited capacity. It can contain approximately seven independent units of information.

Maintenance Rehearsal: To keep information in short-term memory for more than a few seconds, you usually have to repeat the information to yourself or out loud. This is what psychologists mean by maintenance rehearsal. When you look up a telephone number, for example, you can remember the seven digits long enough to dial them if you repeat them several times. If you are distracted or make a mistake in dialling, the chances are you will have to look up the number again. It has been lost from short-term memory. By using maintenance rehearsal (repeating the telephone number over and over again), you can keep the information longer in short-term memory.

Psychologists have measured short-term memory by seeing how long a participant can retain a piece of information without rehearsal. The experimenter shows the participant three letters, such as CPQ, followed by three numerals, such as 798, one second later. To prevent rehearsal, the participant has been instructed to start counting backward by threes and reporting the result in time with a metronome striking once per second. (A metronome is an instrument designed to mark exact time by a regularly repeated tick.) If the participant performs this task for only a short time, she or he will usually remember the letters. If kept from rehearsing for 18 seconds, however, recall will be no better than a random guess; the information is forgotten. Short-term memory lasts a bit less than 20 seconds without rehearsal.

The moment you pay attention to information in sensory memory, that information enters short-term memory. Then that information remains in short-term memory for a few seconds. If you rehearse that information, it stays; if you do not, it disappears. Below is a representation of the process involved in memory.

Chunking: Short-term memory is limited not only in its duration but also in its capacity. It can hold only about seven unrelated items. Suppose, for example, someone quickly reels off a series of numbers to you. You will be able to keep only about seven or eight of them in your immediate memory. Beyond that number, confusion about the numbers will set in. The same limit is there if the unrelated items are a random set of words. We may not notice this limit to our capacity because we usually do not have to store so many unrelated items in our immediate memory. Either the items are related (as when we listen to someone speak), or they are rehearsed and placed in long-term memory.

The most interesting aspect of this limit, discovered by George Miller (1956), is that it involves about seven items (plus or minus two items) of any kind. Each item may consist of a collection of many other items, but if they are all packaged into one chunk, then there is still only one item. Thus we can remember about seven unrelated sets of initials, such as COMSAT, DDT, SST, or the initials of our favorite radio stations, even though we could not remember all the letters separately. This is referred to as chunking because we have connected, or chunked, them together; in other words, DDT is one item, not three.

One of the tricks of memorizing a lot of information quickly is to chunk together the items as fast as they come in. If we connect items in groups, we have fewer to remember. For example, we remember new phone numbers in two or three chunks (555-6794 or 555-67-94) rather than as a string of seven digits (5-5-5-6-7-9-4). We use chunking to remember visual as well as verbal inputs.

Even with chunking, storage in short-term memory is only temporary. Information is available, generally, for less than 20 seconds and no more than 30 seconds, assuming no rehearsal has occurred. After that, it is part of the long-term memory, or it is lost. Short-term memory contains information that is of possible interest. Information worth holding on to must be rehearsed with the intent to learn in order to transfer it to long-term memory. Rehearsal without intent to learn yields no transfer.

The Primacy-Recency Effect: Read the grocery list at the right. Immediately after reading this list, write down as many of the items as you can. Which terms did you remember? The primacy-recency effect refers to the fact that we are better able to recall information presented at the beginning and end of a list. Most likely, you remembered the first four or five items in the list because you had more time to rehearse them. This is the primacy effect. You may have also recalled the last four or five items in the list because they were still accessible in short-term memory. This is the recency effect. However, you may have forgotten the middle items in the list. When trying to remember the middle items in a list, such as this one, your attention is split between trying to remember previous items and trying to rehearse new ones.

Working Memory: Short-term memory is also called working memory. Working memory serves as a system for processing and working with current information. Working memory includes both short-term memory (events that just occurred) and information stored in long-term memory, now recalled for current information.

C. Long term memory (LTM)

This is a virtually permanent storage facility. Long-term memory refers to the storage of information over extended periods of time. Once information has been transferred from the STM to LTM, it remains there. It is the system of holding information n received minutes, days or years ago or since childhood.

Information in LTM is not stored like a piece of paper in a filing cabinet; it is stored according to categories or features. You reconstruct what you must recall when you need it. When you say a friend has a good memory, you probably mean he or she can recall a wide variety of information accurately. The capacity of long-term memory appears to be limitless. Long-term memory contains representations of countless facts, experiences, and sensations. You may not have thought of your childhood home for years, but you can probably still visualize it.

Human memory is usually compared to a computer; however, unlike a computer, people can never fill their long-term memories so full that there is no room left for storage. In addition to this, the capacities of sensory memory and short-term memory differ, as shown in the following table.

Types of Long-Term Memory: For almost a century, the study of memory focused on how long information was stored for usage. Then a Canadian psychologist, Endel Tulving (1972), proposed that we have two types of memory.

Semantic memory is our knowledge of language, including its rules, words, and meanings. We share that knowledge with other speakers of our language.

Episodic memory is our memory of our own lives, such as when we woke up this morning. Stored here are personal things where the time of occurrence is important. Everyone’s episodic memory is unique. L.R. Squire (1987) proposed a related model of memory.

Declarative memory involves both episodic and semantic memory. This is information you call forth consciously and use as you need it.

Procedural memory does not require conscious recollection to have past learning or experiences impact our performance. One form of procedural memory involves skills, learned as we mature, including both complex skills such as swimming or driving a car and simple skills such as tying a tie. As we gain a skill, we gradually lose the ability to describe what we are doing. Other types of procedural memory, such as fear of bugs, include habits and things learned through classical conditioning.

Contents in the LTM have been worked upon and put into meaningful or associative terms-i.e. the contents have been coded-this is called retention. LTM has an infinite capacity, dependent only upon the efficiency of the coding and organisation process of an individual. Below is a representation of the process involved in memory.

Recall or rehearsal

Source: Denis Child (1997:153)

Enhancing memory

We cannot learn anything if we could not remember. Good teaching helps in remembering and bad teaching helps forgetting. If we are to help our pupils to remember what we teach them, we need to teach them by good teaching methods that would help them remember. Techniques for improving memory are based on efficient organisation of the things you learn and on chunking information into easily handled packages.

(a) Use of Meaningfulness and Association: A more efficient way of remembering new information involves elaborative rehearsal. In this method, you relate the new information to what you already know. The more meaningful something is, the easier it will be to remember. For example, you would be more likely to remember the six letters DFIRNE if they were arranged to form the word FRIEND. Similarly, you remember things more vividly if you associate them with things already stored in memory or with a strong emotional experience. The more categories a memory is indexed under, the more accessible it is. If an input is analysed and indexed under many categories, each association can serve as a trigger for the memory.

If you associate the new information with strong sensory experiences and a variety of other memories, any of these stimuli can trigger the memory. The more senses and experiences you use when trying to memorise something, the more likely it is that you will be able to retrieve it, a key to improving memory. In addition, how you originally learn or remember something influences how readily you recall that information later. If a bit of information is associated with a highly emotional event or if you learned this bit of information in the absence of interference, you will more easily recall that information because of the strength of that memory.

(b) Mnemonic Devices: Techniques for using associations to memorise information are called mnemonic devices. The ancient Greeks memorized speeches by mentally walking around their homes or neighbourhoods and associating each line of a speech with a different spot, called the Method of Loci. Once they made the associations, they could recall the speech by mentally retracing their steps and picking up each line. The rhyme we use to recall the number of days in each month (“Thirty days has September”) is a mnemonic device. In the phrase “Every Good Boy Does Fine,” the first letters of the words are the same as the names of the musical notes on the lines of a staff (E, G, B, D, and F).

Another useful mnemonic device is to form mental pictures. Suppose you have trouble remembering the authors and titles of books or which artists belong to which schools of painting. To plant the fact in your mind that John Updike wrote Rabbit, Run, you might picture a RABBIT RUNning UP a DIKE. To remember that Picasso was a Cubist, picture someone attacking a giant CUBE with a PICKAX, which sounds like Picasso (Lorayne & Lucas, 1974). Mnemonic devices are not magical. Indeed, they involve extra work; making up words, stories, and so on. The very effort of trying to do this, however, may help you remember things.

(c) Motivation– We must stimulate the curiosity of the learners by providing interesting activities from which learners can ask. This helps pupils to have the desire to learn and pay attention, revise etc. Reward pupils in order to develop values and positive attitudes towards learning.

(d) Teaching from experience or known to unknown/. This helps remembering and learning.

(e) Use of simple language– words that pupils can understand not difficulty ones.

(f) Practice/revision – in using new knowledge is essential for remembering what has been learned e.g. maths multiplication and division may need practice after teaching.

(g) Repetition-that teachers should ensure that their pupils repeat what they have learned e.g. poems, word meanings, rhythmic teaching though there is a danger in its use word meaning is not taken by pupils e.g. instead of pupils rhyming “weak and sinful though we be” pupils may say “ we can sing, full though we be” For similar reasons, a good way to protect memory from interference is to over-learn it, i.e. to keep on rehearsing it even after you think you know it well. Another way to prevent interference while learning new material is to avoid studying similar material together. Instead of studying history right after political science, study biology in between. Still, another method is to space out your learning. Trying to absorb large amounts of information at one sitting results in a great deal of interference. It is far more effective to study a little at a time, called distributed practice.

(h) Frequent testing/revision- helps the same way repetition does it. Children should be taught to test themselves also so that they discover what they have learned.

(i) Using teaching and learning aids– children should also make and draw such things for good remembering to take place.

(j) Context learning-refers to the place in which teaching and learning is taking place e.g. colours, noise, lighting etc. Memory is more effective when the conditions of recall are identical at the time of learning.

(k) Serial learning– the teacher should look at the logical presentation of ideas and their organisation e.g. introduction; body; conclusion. Emphasis should be put at every stage to enhance learning.

Above all, children cannot remember well what they have learned if they are hungry, sick and bored. A healthy body is necessary as an alert mind for all kinds of learning. Having enough sleep is vital for health memory.