Memory allows us to retrieve a vast amount of information to which we have been exposed. We are able to remember the name of a friend we haven't been in touch with for decades and to re-call details of a picture that hung in our bedroom as a child. At the same time, though memory failures are not uncommon. We may forget where we left the keys to the car or be unable to answer an examination question about material that we studies just a few hours earlier. All learning implies memory. If we remembered nothing from our experiences we could learn nothing life would consist of momentary experiences that had little relation to one another. We could not even carry on a simple conversation. Without memory you could not even reflect upon yourself.
Three stages of memory
Suppose one morning you are introduced to a student and told that her name is Bukola. That afternoon you see her again and say something like "You are Bukola. We met this morning". Clearly you have remembered her name. But what exactly did you do? Your minor memory feat can be broken into three stages. First, when you were introduced, you somehow deposited Bukola name into memory. This is the encoding stage. You transformed a physical phenomenon (sound waves) that corresponds to her spoken name into the kind of code that memory accepts, and you placed that code in memory. Second, you retained or stored, the name during the time between the two meeting. Thus is the storage stage. And third, you recovered the name from storage at the time of your second meeting. This is the retrieval stage.
Memory can fail at any of these three stages. Had you been unable to recall Bukola's name at the second meeting, this could have reflected a failure in encoding, storage, or retrieval current research on memory is aimed at specifying the operations that occur at each stage in different situations and explaining how these operations can go awry and result in memory failures.
Three Types of Memory
Do the three stages of memory operate in the same way in all memory situations? Research suggests that they do not. Memory seems to differ between those situations that require us tostore material for a matter of seconds and those that require us to store material for longer intervals. From minutes to years. The former situations are said to tap short-term memory. whereas the later reflect long-term memory.
We can illustrate this distinction by amending our story about meeting Bukola suppose that during the first meeting, as soon as you had heard her name, a friend came up and you said, Lola have you met Bukola? In this case, remembering Bukola-s name would be an example of short-term memory.
You retrieved the name after only a second or so. Remembering her name at the time of your second meeting. Would be an example of long-term memory, for now retrieval would take place hours after the name was encoded. When we recall a name immediately after encountering it, retrieval seems effortless, as if the name were still active, still in our consciousness. But when we try to recall the same name hours later, retrieval is often difficult, as the name is no longer conscious. This contrast between short and long-term memory is similar to the contrast between conscious knowledge and the sub-conscious knowledge we have but are not currently thinking about. We can think of memory as a vast body of knowledge. Only a small part of which can ever be active at any moment. The rest is passive. Short-term memory corresponds to the active part. long-term memory to the passive.
Sensory Memory
A momentary flash of lighting, the sound of a twig snapping, and the sting of a pinprick all represent stimulation of exceedingly brief duration, but they may nonetheless provide important information that can require some response. Such stimuli are initially and briefly stored in sensory memory, the first repository of the information that the world presents to us. Actually, the term. "sensory memory" encompasses several types of sensory memories, each related to a different source of memory information. There is iconic memory, which reflects information from our visual system, echoic memory which stores information coming from the ears, and corresponding memories for each of the other senses.
Regardless of the individual subtypes, sensory memory in general is able to store information for only a very short time. If information does not pass to short-term memory, it is lost for good. For instance, iconic memory seems to last less than a second, although if the initial stimulus is very bright, the image may last a little longer (Long & Beaton, 1982).
Econic memory fades within three or four seconds (Darwin. Turvey & Crowder 1972). However, despite the brief duration of sensory memory.
In sum, sensory memory operates as a kind of snapshot that stores information which may be of a vital, auditory, or other sensory nature for a brief moment in time. But it is as if each snapshot, immediately after being taken, is destroyed and replaced with a new one. Unless the information in the snapshot is transferred to some other type of memory, it is lost.
Short-term Memory: Our Working Memory
Because the information that is stored briefly in our memory consists of presentations of raw sensory stimuli, it is not meaningful to us. In order for us to make sense of it and to allow for the possibility of long-term retention, the information must be transferred to the next stage of memory. Short-term memory is the memory store in which material first has meaning, although the maximum length of retention is relatively short.
The specific process by which sensory memories are transformed into short-term memory is not yet clear. Some theorists suggest that the information is first translated into graphical representations or images, and others hypothesize that the transfer occurs when the sensory stimuli are changed to words (Baddeley & Wilson, 1985). In fact, the specific amount of information that can be held in
short-term memory has been identified. The transfer of material from short to long-term memory proceeds largely on the basis of rehearsal, the repetition of information that has entered short-term memory. Rehearsal accomplishes two thing. First, as long as the information is repeated, it is kept alive in short-term memory. More important, however, rehearsal allows us to transfer the material into long-term memory.
Long-Term Memory
The final store house material that makes its way from short-term memory to long-term memory enters a store house of almost unlimited capacity. Like a new book delivered to a library, the information in long-term memory is filed and catalogue so that it can be retrieved when we need it.
Evidence of the existence of long-term memory, as distinct from short-term memory, comes from a number of sources for example, people with certain kinds of brain damage have no lasting recall of new information following the damage, although people and events stored in memory prior to the injury remain intact (Milner. 1966) because short-term memory following the injury appears to be operational B can be recalled for a very brief period and because information that was encoded and stored before the injury can be recalled we can infer that there are two distinct types of memory Bone for short-term and one for long-term storage.
Results from laboratory experiments are also consistent with the notion of separate short and long-term memories. For examples, in one set of studies people were asked to recall a relatively small amount of information (such as a set of three letters). Then, to prevent practice of the initial information, participants were required to recite some extraneous material aloud, such as counting backward by threes (Brown, 1958). By varying the amount of time between presentation of the initial material and the need for its recall, investigations found that recall. was quite good when the interval was very short but declined rapidly thereafter. After fifteen seconds had gone by, recall lowered at around 10 percent of the material initially presented.
Apparently, the distraction of counting backward prevented almost all the initial material from reaching long-term memory. Initial recall was good because it was coming from short-term memory, but these memories were lost at a rapid rate Eventually, all that could be recalled was the small amount of material that had made it's way into long-term storage despite the distraction of counting backward.
Information
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Sensory Memory
Loss of information typically within 3-4 seconds
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Short-term Memory
Loss of information within 15-20 seconds
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Long-term Memory
Measures of Retention
The level of acquisition can be measured by the correct responses in a set of test trials, or by the number of trials required to reach a particular criterion. The three principal measures of retention are: recall, recognition and savings score.
Recall: In recall measure of retention, the subject is required to supply additional information having been given a minimum cue. Essay questions and completion questions are often recall tests of retention. For example, suppose an individual is being asked to name the capital city of Italy and with no option of
names being given; the individual is expected to provide the answer without additional prompting.
Recognition: This requires the subject to identify the correct answer, from a number of options available. Matching or multiple choice questions are usually recognition tests of retention.
Savings Score: In some situations, subjects may have to re-learn materials they have learned before. The amount of tine or the number of trials required for re-learning may then be compared to the amount of time or number of trials required for original learning. Ebbighans (1964) devised the savings score and defined it as the amount of time or number of trials required for original learning minus the amount of time or number of trials required for re-learning divided by the amount of time or number of trials required for original learning then multiplied by 100.
R/o Savings Score
For example, Ojo takes 15 minutes to learn a serial verbal list of nonsense syllables to make one perfect recitation. One week later, Ojo re-learns the list in 9 minutes, what is his savings score? The saving score
The level of acquisition can be measured by the correct responses in a set of test trials, or by the number of trials required to reach a particular criterion. The three principal measures of retention are: recall, recognition and savings score.
Recall: In recall measure of retention, the subject is required to supply additional information having been given a minimum cue. Essay questions and completion questions are often recall tests of retention. For example, suppose an individual is being asked to name the capital city of Italy and with no option of
names being given; the individual is expected to provide the answer without additional prompting.
Recognition: This requires the subject to identify the correct answer, from a number of options available. Matching or multiple choice questions are usually recognition tests of retention.
Savings Score: In some situations, subjects may have to re-learn materials they have learned before. The amount of tine or the number of trials required for re-learning may then be compared to the amount of time or number of trials required for original learning. Ebbighans (1964) devised the savings score and defined it as the amount of time or number of trials required for original learning minus the amount of time or number of trials required for re-learning divided by the amount of time or number of trials required for original learning then multiplied by 100.
R/o Savings Score
=original learning BreBlearning x 100
_____________________
original learning
For example, Ojo takes 15 minutes to learn a serial verbal list of nonsense syllables to make one perfect recitation. One week later, Ojo re-learns the list in 9 minutes, what is his savings score? The saving score
= 15 B9 x 100
____________
15
= 6 x 100
__________
15
=40%.
Forgetting refers to the person's inability to produce the required response at the end of retention interval.
(1) Failure to Retrieve: One theory suggests that forgetting occurs because a person fails to retrieve materials that are already stored. This failure could be a function of poor organisation in storage, poor prompting. inappropriate motivation or some other variables that may keep a person from recalling the stored materials.
(2) Disuse: Another theory of forgetting proposes that loss of retention occurs because of the disuse of learned materials. Failure to use what we have learned will lead to memory decay and withering away of stored materials.
(3) Distortion of the Memory Trace: This theory suggests that forgetting occurs because items are partially stored with inaccurate or inappropriate descriptive labels attached to them. This alters the meaning of such stored materials and thus makes accurate recollection impossible.
(4) Interference: One of the best documented theories of forgetting is based on the idea that loss of retention results from interference from other materials. McGeoch (1942) distinguished between two different types of interference: retroactive interference and proactive interference.
Retroactive interference refers to the inhibiting effects of later learning on earlier learning, whereas proactive interference refers to the competition of earlier learning with later learning. Imagine you are a subject in a memory study. The experimenter shows you a list of words (A) and then asks you to study it. Later, he shows you yet another list of words (B). Assuming the two lists are similar, if you are asked to recall list B. you might recall some items in list A. If this happens, we say your memory for list A has interfered with your recall of list B. This type of interference we call proactive interference because earlier items act ahead to interfere with later items. If on the other hand, you are asked to recall list A, you might recall some of the items in list B. This type of interference is called retroactive interference because later items act backwards to interfere with earlier items.
In summary, learning is defined as a potential change in behaviour resulting from experience in processing information. The foregoing chapter discussed the different approaches to learning. Classical and instrumental conditions are two principal associationist approaches to learning that view learning as being based on association between ideas. We also emphasised cognitive approach to learning as a mental process, while social learning approach is viewed as a process of learning resulting from the observation of others. Also discussed in this chapter are other relevant concepts related to learning such as extinction. shaping, reinforcement, punishment as well as the practical implications of these concepts. Adequate treatment was given to variables affecting acquisition, memory and theories of forgetting.
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