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FORGETTING ??? FORGETTING Forgetting refers to the inability to retrieve previously stored information. When you forget something it means that it is unavailable to you at the time you are trying to remember it. The information may be stored in your memory, but for some reason you are unable to retrieve it. Although forgetting results in the loss of information and many skills, if you did not forget, your mind would be cluttered with so much information that you would have great difficulty retrieving and selecting the information that you needed. Like remembering forgetting has an adaptive purpose and contributes to our survival and our sanity. THE FORGETTING CURVE Hermann Ebbinghaus was a German psychologist who was the first to scientifically study forgetting in the late 1800’s. To measure the amount of information retained and the rate at which information is forgotten, Ebbinghaus conducted an experiment using himself as the only participant. The experiment involved him learning a series of lists of nonsense syllables, until he could recite them without error on two separate occasions. Ebbinghaus tested his recall for each list after a specific period of time had elapsed from the initial learning. He first learned one list, then tested his recall after a specific delay period. Then he learned another list, tested his recall after another delay period, and so on. The delay ranged from 20 minutes to 31 days. Ebbinghaus was then able to measure the amount and rate of forgetting. - FINDINGS: 20 minutes after initial learning he could remember 58% of nonsense syllables. One hour after learning his retention was 44%. A day later he could recall 34%. A week later his recall had fallen to around 21%. This data, once plotted on a graph became known as the forgetting curve. The forgetting curve shows the pattern of forgetting that occurs over time. Generally the graph shows that forgetting is rapid soon after the original learning, then the rate of memory loss gradually declines, followed by stability in the memories that remain. More than half of the memory loss occurs in the first hour of learning. Virtually all the information that will be forgotten is lost in the first eight hours. This pattern of forgetting tends to occur for a range of materials under many conditions. The more meaningful the material, the slower the rate of forgetting. The amount and rate are also influenced by how well the information was initially encoded- the better the initial learning, the longer the material is likely to be retained. MEASURES OF RETENTION What methods do we use to test what has been retained in memory? Teachers generally use tests or exams. But is your performance on a test or exam a reliable measure of how much information you have retained in memory? There are different types of questions teachers ask, including multiple-choice questions, true/false questions, fill-in-the-blanks, short answer, and essay questions. Research shows that the amount of information that will be retrieved from memory is, at least partly, dependent on the type of question asked. There are three main kinds of measures that are used to determine how much information has been retained: recall, recognition and relearning. RECALL What are the names of the 7 dwarfs? In order to answer this question, you would have searched through your long-term memory, tried to locate the information required, and either have produced or not produced the correct information. RECALL This approach to measuring the amount of information retained in memory is a test of recall. Recall involves being asked to reproduce information with the fewest possible cues to assist retrieval. In an experiment used to measure recall as a measure of retention, participants might be required to learn a list of randomly selected words. Then, after a period of time, they may be required to write, in any order, as many of the words off the list as they can. This method is called free recall. Free recall is involved when participants are only asked to remember as much information as possible, in no particular order. If participants were asked to recall a list of words in the order in which they were presented, researchers would be asking for serial recall. Sometimes the general cue we are provided with to search information in our long-term memory is too general and the list of possible matches is too long. Cued recall makes use of specific cues to aid retrieval. For example; being given the first letter of each of the 7 dwarfs names. RECOGNITION Which of the following are the names of the 7 dwarfs? -Bashful -Happy -Grumpy -Pop -Sleepy -Goofy -Dopey -Sneezy -Doc -Grouchy RECOGNITION Recognition involves identifying the correct information from among alternatives, such as in the previous question. Generally we can retrieve more information when tested by the recognition method than we can with the recall method because the recognition method provides more cues that assist in the location and retrieval of information from long-term memory. In an exam situation, students typically prefer M/C questions or true/false questions to an essay or short answer questions. M/C and true/false questions involve recognising the correct response from among a small number of alternatives, whereas essay question require recall, where there are very few cues. The - - difference between recall and recognition is this: In recall we ask What is the item? In recognition we ask Is this the item? RELEARNING Most people have times when they are unable to recall or to recognise information that has been stored in long-term memory. Even though they are unable to retrieve this information, it does not necessarily mean that it has been forgotten. Relearning or the method of savings, involves learning information again that has been previously learned and stored in long-term memory. Typically relearning something takes less time than it did to learn it originally. If information is learned more quickly the second time it is assumed that there must be some information retained from the first learning experience, whether we realise it or not. HERMANN EBBINGHAUS Ebbinghaus did an experiment using nonsense syllables (eg. Jux, kuv). Nonsense syllables are often used in memory research instead of words so that retention is not affected by the words having some sort of meaning or association with words already stored in memory. When Ebbinghaus measured his memory for what he had learned, he found that even if he could not remember a single item from the original list, he could relearn the list much quicker a second time than he had been able to with the original list. This indicated that some information had been retained from the initial learning. This is also called the method of savings because it can be calculated using the following formula. Savings = (no. of trials for original learning) – (no. of trials for relearning) x 100 (no. of trials for original learning) 1 10 – 5 x 100 = 50% 10 1 Eg. A savings score can also be calculated on the basis of the time taken to relearn information. Savings = (time taken for original learning) – (time for relearning) x 100 (time for original learning) 1 RELATIVE SENSITIVITY OF MEASURES OF RETENTION Recall, recognition and relearning differ in their relative sensitivity as measures of retention. The sensitivity of a measure of retention refers to its ability to assess the amount of information that has been stored in memory. Recall tends to be the least sensitive measure of retention, relearning tends to be the most sensitive measure of retention, and recognition tends to be less sensitive than relearning but more sensitive than recall. In a study by Nelson (1978) on the three measures of retention, 24 university students were used as participants. The experiment consisted of three stages- the initial learning stage, a stage in which recall and recognition of the initial learning were tested and finally a relearning stage. In the first stage, participants were given a series of number-word pairs to learn, such as 49-party and 95horse. The second stage of the experiment required the participants to participate in the testing and relearning stages of the experiment. In the testing stage, participants were required to complete two different types of tests. The first was a test of recall where the participants were given the original number as a cue and were asked to provide the association word that went with it. The second test was similar but required the participants to name the associated words from a list of 20-10 of which were the original words and 10 of which were new, unrelated words. The third stage of the experiment involved relearning the words from the previous list which had been incorrectly recalled and 10 new word pairs. They were then given a recall test on both the new information and the old information. The results showed that a mean score of 48% of the target words were correctly recalled, and 69% were correctly recognised in the testing. Furthermore the percentage of target words correctly recalled during the relearning stage was significantly higher for the old items (88%) than for new items. These results were found to be significant at the p<0.001. What does this mean? v THEORIES OF FORGETTING Psychologists have developed a number of theories to explain why we forget. Forgetting may occur because: 1. The right retrieval cue is not used 2. There is interference from competing material 3. Memory fades through disuse over time RETRIEVAL FAILURE THEORY If you have ever experienced a ‘mental blank’ in an exam or in a job interview, only to recall the exact information at a later point in time, you have experienced retrieval failure. Most of the time we can retrieve information from LTM with relative ease. This is because most of the time you are able to retrieve information from the various storage systems in your LTM using a retrieval cue to locate the relevant information. A retrieval cue is any stimulus that assists the process of locating and recovering information stored in memory. It is a prompt or cue to guide the search and recovery process within memory. According to retrieval failure theory we sometimes forget because we lack or fail to use the right cues to retrieve information stored in memory. This explanation of forgetting suggests that memories stored in LTM are not actually forgotten, but are temporarily inaccessible. Tip-of-the-tongue phenomenon One of the most frequent experiences of retrieval failure is the tip-of-the-tongue phenomenon (TOT). Tip-of-the-tongue is the feeling of being aware of knowing something, being confident that you will remember it at any moment, but not being able to retrieve the information at that point in time. When we experience this it seems that even though we can’t say the word, we do have specific information about it eg. What it starts with, how many syllables it has or what it rhymes with. This suggests that the TOT phenomenon involves partial retrieval in which bits of information can act as retrieval cues. Brown and McNeill (1966) demonstrated the TOT phenomenon by asking participants to memorise a list of words that are generally not in everyone’s vocabulary; for example sampan which is a wooden Chinese fishing boat. The words that participants came up with when trying to recall the correct word sometimes resembled the word in meaning (‘junkboat’) but most often resembled it in sound (‘sarong’). As a result they believed that a word is stored in a specific location that contains information about its sound and its meaning. Therefore we can retrieve words according to either characteristic. These words are also linked to other similar words through memory pathways which is often why we are able to retrieve similar words in place of the one we really want. They concluded that phonetic and semantic features are needed in the retrieval of a word. INTERFERENCE THEORY Recall can become difficult when we are trying to remember a lot of similar information. This is partly because similar memories interfere with the retrieval of one another. This highlights a second reason for forgetting- that memories can interfere with one another. Interference theory proposes that forgetting in LTM occurs because other memories interfere with the retrieval of what we are trying to recall, particularly if the other memories are similar. If learning of similar material occurs close in time, interference is more likely. There are two types of interference: 1. Retroactive interference 2. Proactive interference RETROACTIVE INTERFERENCE When new information interferes with the ability to remember old information, psychologists refer to the interference as retroactive interference. Eg. You are at a party and you are introduced to a guy named John. Not long after you are introduced to Jim. After a while you bump into John again but accidentally call him Jim. With retroactive interference, new learning interferes with the retrieval of previously learned material. PROACTIVE INTERFERENCE Interference also works in the opposite direction. Information learned previously can interfere with our ability to remember new information. This effect is called proactive interference. According to interference theory, interference primarily comes from memories of similar information. MOTIVATED FORGETTING Motivated forgetting refers to the inability to retrieve information because the individual derives some benefit from not remembering. Sigmund Freud was one of the first to consider the idea of motivated forgetting, which he called repression. Repression involves unconsciously blocking a memory of an event or experience from entering conscious awareness. He claimed that it was an unconscious, unintentional process through which the individual may avoid feelings of anxiety about traumatic events. An important feature of repressed memories is that although they may not be readily accessible to conscious recollection, they may still be retained. Eg. Hypnosis Memories that are retrieved from the unconscious are called recovered memories. Not all motivated forgetting is unconscious- an individual may quite intentionally and consciously want to forget something. This is called suppression. Suppression involves being motivated to forget an event or experience by making a deliberate conscious effort to keep it out of conscious awareness. The person knows that the memory is there, however they choose not to think about it. Brain imaging techniques show that when a person is trying to suppress a memory the left and right frontal lobes are more active and there is less activity is the hippocampus where information is usually recalled. Many psychologists accept that memory can be affected by an individual’s conscious or unconscious needs, fears, anxieties, and desires. DECAY THEORY Some psychologists suggest that forgetting is a process of decay. Memories that are formed and not used begin to fade, become weaker with time, and eventually decay to the point where they can no longer be recollected- that is, they are forgotten. This theory, known as decay theory, was first proposed by Edward Thorndike in 1914. Decay theory explains forgetting based on the assumption that when something new is learned, a memory trace or neural imprint of the experience that contains the stored information is formed in the brain; the trace gradually fades over time through disuse unless it is reactivated by being used. Decay theory suggests that memories that are not retrieved or rehearsed dissipate over time as the synaptic connections between neurons that constitute the memory trace begin to degrade. Forgetting seems to be a combination of the fading of memory traces, interference, or the use of an inappropriate retrieval cue. Manipulation and improvement of memory Research findings indicate that much of what we recall from long term memory is not an accurate representation of what actually happened previously. Instead, it is a logical account of what might have happened, shaped by our thoughts, attitudes and beliefs and by who we are as individuals. The details of human memory can change over time. Confidence in memory is no guarantee that it happened. How do distortions creep into our memories? A new memory is not a recording, it is actively reconstructed. To form a new memory you actively organise and encode different types of information: visual, auditory, tactile etc. When you later try to retrieve this memory you have to reconstruct the details of the memory. In this process various factors can create errors. Manipulation of memory Frederick Bartlett’s (1932) study on the reconstructive nature of memory pg 393. Elizabeth Loftus also studied this in regards to eye witness testimony. She found that eyewitnesses reconstructed their testimony and therefore it was not always accurate. Most of her studies typically involved showing participants a short film, video or slides of a car accident. Participants were then asked specific questions about the scene they ‘witnessed’. Sometimes, information that was not present in the actual scene or which contradicts the scene is introduced. At other times leading questions are asked. Loftus’ research makes it clear that leading questions can be used to manipulate memory. A leading question is a question that has content or is phrased in such a way as to suggest what answer is desired or to lead to the desired answer. These kinds of questions can implant memories into a witnesses memory and falsely produce the things that they think they recall. Studies by Elizabeth Loftus Flow chart on the two experiments pg 394. Studies by Elizabeth Loftus Although eyewitnesses may think, feel and behave differently when observing a crime in the laboratory as compared with realworld settings, eyewitness testimony cannot be regarded as faultless, even when the witness is trying to be truthful. Loftus suggests that whenever we retrieve a memory it does not actually represent the original memory but a reconstruction of what we actually stored. IMPROVEMENT OF MEMORY We can rely on specific mental strategies if we want to improve our memory. Sometimes we are able to remember information simply because it stands out or is unusual. Other information requires conscious effort in order for it to be remembered. To ensure that information goes beyond sensory memory we must pay attention to it. It must also be organised and integrated into LTM with information already in LTM. CONTEXT- AND STATEDEPENDENT CUES Another effective way of enhancing retrieval from LTM is to re-create the conditions under which the required information was originally learned. This approach is based on the encoding specificity principle. This principle involves a general ‘rule’ that the more closely the retrieval cues match the original learning conditions, the more likely it is that the information will be recalled. CONTEXT-DEPENDENT CUES Why is it that police investigating a crime may take an eyewitness back to the crime scene, particularly if the witness is having some trouble recalling some of the details of what they saw which are critical to the investigation? The answer is based on research findings that cues in the environment may be important in helping to locate and retrieve related memories. Context-dependent cues are environmental cues in the specific context (setting) where a memory was formed, which act as retrieval cues to help access the memories formed in that context. These cues may include the sights, sounds and smells within the specific situation. The context dependency of certain memories helps explain why an eyewitness may recall apparently forgotten information about a crime when they return to the scene of the crime. STATE-DEPENDENT CUES State-dependent cues are associated with an individual’s internal physiological and/or psychological state at the time the memory was formed, which act as retrieval cues to help access those memories. It seems that taking a drug can produce an internal state with unique psychological and physiological characteristics, aspects of which may become encoded with new memories. At a later point, the same internal state can provide additional retrieval cues that assist recovery of information from memory. Your mood also provides state-dependent cues. We seem to associate good or bad events with their accompanying emotional state. This means that our emotional state becomes a retrieval cue when we feel good or bad again, and they trigger memories that are consistent with the mood. However, when we are happy, happy events are recalled; but when we feel down, our minds can become flooded with sad or negative events of the past which in turn darken our interpretations of current events. MNEMONIC DEVICES Techniques for enhancing or improving memory are known as mnemonic devices. A mnemonic device is any internal strategy or method that makes it easier to encode, store or retrieve information. Mnemonic devices may be visual or verbal, and they generally impose some sort of organisation on the material to be remembered. Mnemonic strategies are always entirely internal. Memory aids such as writing a shopping list are not mnemonic strategies because they rely on external items (in this case a pen and paper). Acronyms Acrostics Peg word method Narrative chaining Method of loci Acronyms Acronyms involve using the first letter of each word to be remembered to create a pronounceable word or name. E.g. Sudden Infant Death Syndrome has become the acronym SIDS. The letters of the abbreviation act as a retrieval cue. They are essentially a type of chunking. The abbreviation must be pronounceable. Acrostics Acrostics involve constructing a phrase or sentence from words that begin with the first letter of each word of the information to be recalled. E.g. E, G, B, D, F are the names of the notes on the lines of the staff otherwise known as ‘Every Good Boy Deserves Fruit’. Acrostics can be useful when trying to remember information in a sequence. Peg-word method The peg-word method uses an easily remembered rhyme to visually associate items to be remembered. E.g. pg 405. When recalling the information you recite the rhyme and the words that are associated with each line can be recalled. This method is more effective when the rhyming word and the item to be remembered can be linked. This is generally a two step process: 1. Memorise key words that can be associated with numbers (one-bun) 2. Create an image of the items you need to remember with key words. E.g. Your shopping list One – bun must include: -Toothpaste Two – shoe -Oranges Three – tree -Ham -Yoghurt Four – saw -Eggs Five – hive NARRATIVE CHAINING Narrative chaining links unrelated items to create a story-like sequence of events. Construct a story that involves the following items in the order in which they appear here: Sunscreen, cereal, soup, chocolate, butter, English muffins. For example in a study using this method participants showed that on average those who used narrative chaining remembered 93% of words learnt and those who used no method remembered only 13%. METHOD OF LOCI The method of loci is a mnemonic that relies on the use of a well-learned pathway with distinct locations that can be associated with the items to be remembered. To use the method of loci, you need to recall a sequence of distinct locations and associate them with each word to be remembered. Imagine yourself walking through a house and associate each word on a list with an item in each room. When you need to recall a list of words, imagine yourself revisiting the house and walking through the same rooms-this will probably cause you to remember the word you associated with each location. Experimental investigation of the method of loci has found that participants more than doubled the number of words they were able to recall when using the method of loci, compared to when relying on free recall.