Organization
Organization is another form of deep processing. Research has shown that organization creates a lasting memory like semantic processing. It is implicit rather than explicit memory and no conscious processing needs to take place. Mandler (1967) conducted and experiment in which he gave participants a pack of 52 picture cards, each of which had a word printed on it. Participants were then asked to sort the cards into piles, using anything from two to seven categories, and could go by any system the wished. They were then asked to carry on with the sorting until they came to two identical sorts. If anyone was still trying to do this after 1 ¼ hours then they were excluded from the experiment. He found out that most of the participants took six sorts to gain 95% consistency. At this point, they were given an unexpected free recall test. Recall was poorest for those who had decided to use only two categories, and the best from those who choose to use seven categories. Mandler concluded that “memory and organization are not only correlated but organization is a necessary condition for memory”.
Distinctiveness
Memory traces that are distinctive or unique in some way will be more memorable than memory traces that closely resemble others. Eysenck and Eysnck (1980) tested this theory by using nouns having irregular grapheme-phoneme correspondence (i.e. words not pronounced in line in line with punctuation rules, such as “comb” with its silent ‘b’). The participants were asked to perform the shallow (non-semantic) tasks of saying such words as if they were regular, (i.e. pronouncing the ‘b’ in comb). This resulted in a unique memory trace, so that this was the non-semantic, distinctive condition.
When an unexpected test of recognition memory, words in the non-semantic, distinctive condition were much better remembered than those in the non-semantic, non-distinctive condition.
Distinctiveness depends in part on the context in which a given stimulus is processed, for example the name ‘Emma’ would not stand out if it was with five other names but it would if it was placed with some other foreign words.
Encoding in short term memory
It is a common idea that short-term memory has less capacity and shorter duration. The concept of ‘encoding’ is less familiar though. Encoding is the way information is stored in memory. One of the ways to compare encoding is in terms of acoustic or semantic processing. Acoustic is the sound of a word and semantic is the meaning of a word.
Short-term and long-term memories differ in the way which information is encoded. Baddeley (1966) found that if participants were asked to recall words immediately from short-term memory they did not confuse words that had the same meaning, but they often confused words that sounded similar. The opposite was true for long-term memory. This suggests that short-term memory largely uses an acoustic code, sorting words in relation to how they sound and long-term memory mainly uses a semantic code, storing words according to their meaning.
Evidence about Short-term Memory from Studies of Brain Damage
A strong piece of evidence for a distinction between short and long-term memory has come from the study of brain damaged patients. Amnesia is when a person has lost a lot of their long-term memory, often due to an accident that has caused brain damage. These people usually have almost normal short-term memory. In contrast some people who have brain damage have no problem with their long-term memory, but there short-term memory is disabled.
Shallice and Warrington (1970) studied KF, who suffered brain damage after having a motorcycle accident. KF had no problem with his long-term memory but his digit span was only two items where the average person can usually remember seven items in short term memory. These findings suggest that different parts of the brain are involved in short term and long-term memory.
Warrington and Shallice then went on to find out that KF’s short term forgetting of auditory letters and digits, (what he heard) was much greater than his forgetting of visual stimuli. In conclusion they suggest that there is not just one short-term memory, but a number of different stores, each represented in different parts of the brain. They also found out that KF’s problems lied with what they called the “auditory-verbal short-term store”. These distinctions with in short-term memory are important.
Capacity of Long-term memory
The capacity of the human brain for storing information is enormous, even in comparison with computers. People are able to remember a vast amount of information – especially when you consider the kind of information that is stored in memory: the route you take to get home, what your primary school used to look like, the names of what people you know etc…. There is probably some limit to how many brain cells you can use but it seems likely that we never reach this upper limit in long term memory. It is not a limited capacity store – where as short term memory is.
Duration in Long-term memory
It is very difficult to measure the duration in long-term memory, but psychologists have conducted research into Very Long-term memory. It is said that the elderly never loose their childhood memories and many skills, such as riding a bike are never forgotten. Bahrick, Bahrick and Wittinger (1975) produced a demonstration of very long-term memory by using photography from high school yearbooks. Ex-students were asked to name other students out of the yearbook and most people remembered nearly 90% of all the people featured in the yearbook. This supports the view people do have long term memories that are not confabulated.
Varieties of Long-term memory
We can store large amounts of very different information, from what we learn at school, to where we live and what our friends and family are like. It seems improbable that all this knowledge is stored within a long-term memory store. This is important because it could be, for example that different kinds of memory have greater duration or are affected by forgetting in different ways. If there is more than one long-term store, we need to work out the number and nature of long-term stores that we possess.
Episodic and semantic memory
Tulving (1972) argued that there were two different types of long term memory: episodic memory and semantic memory.
Episodic memory has an autobiographical flavour. It contains the memories of specific events or episodes occurring in a particular place or at a particular time. Memories of what you did yesterday or had for lunch last weekend are examples of episodic memory.
Semantic memory contains information about our knowledge of the rules and the word of our language, about how to calculate percentages and how to fill your car with petrol etc.
Tulving backed up his theory to support the distinction between episodic and semantic memory by injecting a small amount of gold into volunteers, including himself. They thought about personal events or about information in semantic memory. Blood flows in different areas of the brain were recorded. Increased blood flow indicated that a certain part of the brain was active. When participants were using their episodic memory, parts of the frontal cortex were active, where as semantic memory was associated with high levels of blood flow in the posterior or back regions of the cortex. This fits the view that there are at least partially separate episodic and semantic memory systems.
Explicit and Implicit memory
When people are asked to recall specific pieces of information, it is known as using their explicit memory, which is “revealed when performance on a task requires conscious recollection of previous experiences”. This can be contrasted with implicit memory, which is “revealed when performance on a task is facilitated in the absence of conscious recollection”. The term ‘explicit’ means to be stated directly or plainly, where as implicit means that something is implied or assumed but no one tells you specifically.
This distinction between explicit and implicit memory is clearly important when considering the value of memory research because such research often uses explicit memory.
Declarative and procedural knowledge systems
Cohen and Squire (1980) argued that long term memory is divided into two memory systems: declarative knowledge and procedural knowledge. This distinction is related to that made by Ryle (1949) between ‘knowing that’ and ‘knowing how’.
Declarative knowledge corresponds to knowing that. For example you know that you had roast beef on Sunday or you know that queen Elizabeth is our current monarch.
Procedural knowledge corresponds to knowing how, and refers to the ability to perform actions like how to ride a bike or how to play the piano. Explicit memory depends on the procedural knowledge system.
What are three explanations for forgetting in long-term memory?
Trace decay theory – forgetting may also be due to slow physical decay of the memory traces in long term memory, as has been suggested in short term memory. It has proved hard to study these changes and so studies of trace decay have been indirect. It is assumed if a person does nothing during the time of initial learning and subsequent recall (called the retention interval) and they forgot the material, then the only explanation can be that the trace has disappeared. Trace decay may play some casual role in forgetting but it is by no means the main explanation.
Interference theory – In the 1930’s to 1950’s psychologists believed that the cause for forgetting was interference. Interference is when another set of information comes in and wipes out all or part of the other memory. When previous learning interferes with late learning and retention, this is known as proactive interference. When later learning disrupts memory for earlier learning, this is known as retroactive interference (which was the kind of interference proposed for short term memory.)
Cue dependent forgetting – this is a classic example of forgetting due to lack of accessibility. The information is in memory, but it cannot be accessed until a specific or appropriate cue is given and suddenly you can remember it. It is available but not accessible all the time.
What is the trace decay theory and how good an explanation is it for forgetting in long-term memory?
If the trace decay theory is correct then we could expect people to remember the same whether they were awake or asleep. But people forget more when they are awake due to other activities. Forgetting when people are asleep may be because of interference inn dreams. So trace decay is a valid theory but it is not the main reason for forgetting in long-term memory as there are other factors and it is not easy to assess.
Explain the terms proactive and retroactive interferences.
Proactive interference – past experiences interfere with current recall. Participant’s recall is tested from a second list of paired associates. Performance of the experimented group (who learned both lists) is compared with a control group (who learned only the second list). This should mean that the experimental group do more than the controlled group.
Retroactive interference – subsequent interferes with recall of material learned earlier. Participants recall is tested on the first list of paired associates. Performance of the experimental group (learned both lists) is compared to the control group (learned only the first list). Retroactive interference should mean that the experimental group do less well.
Endel and Tulving’s study of cue dependent forgetting
Title – Endel and Tulving’s study of cue-dependant forgetting and interference
Aim – To find out the differences between cue-dependant forgetting and the interference theory of forgetting.
Procedure – Participants were given word lists. There were six different word lists, each with 24 words. Each set of words was divided into six different categories with four words in each. The words were presented in category order so that the organization and the categories were quite obvious. Some of the participants only learned one list whilst some learned two lists and so on and so on… some learned as many as all six lists. Words were shown one at a time. After each list had been presented, the participants tried to recall the words from all the lists that had been presented. That was totally free cue recall. Finally all the category names were presented, and the participants tried again to recall all the words from all the lists. That was total free cued recall (cued because they were given category names)
Findings – There was strong evidence for retroactive interference in the total free recall condition and when participants were given the cued recall test, the effects of retroactive interference disappeared. No matter how many lists were given to the participant’s recall was always the same for each list when they were given a category names as cues.
Conclusions – There is the possibility that performance improved on the cued-recall
Criticisms task because of practice effect. The participants had completed at least two free recall tests before doing the cued recall and this may have led to better recall. However this cannot explain all the results, such as why recall was the same for all the lists no matter how many were given.
What is meant by the encoding specific principal (ESP) and under which circumstances is recall the best?
Remembering something relies on having the right cues. Tulving (1979) used this notion to put forward his idea encoding specificity principal. This is the idea that the closer the retrieval cue is to the information stored in memory; the greater the likelihood the cue will be successful in retrieving the memory. According to the encoding specificity principal, retrieval (or its opposite forgetting) occurs fairly rapidly and with little thinking involved. However retrieval often involves problem solving activities which take time and conscious thought.
Why according to Freud how may memories be represented and assigned to the unconscious?
Memories may be represented and assigned to the unconscious thought the emotional factor; repression. The concept of repression can be used to explain forgetting. For example, someone who doesn’t like going to the dentist. If they told you that they ‘forgot’ their appointment, you might think that this is a repressed memory – the anxiety caused by the memory in some way made it inaccessible to conscious thought.
What is flashbulb memory and why might it occur?
Flash bulb memory is the long lasting and vivid memories of highly important and dramatic events. Flash bulb memory is as if a flash photograph was taken at the very moment of the event and every detail indelibly printed in memory. The emotional nature of such events contributes to the way in which they are stored in memory. Brown and Kulik suggested that flashbulb memories were distinctive because they are both enduring and accurate. The concept of flashbulb memories seems to contradict the notion that through processing in short term store is needed for good long term memory, and to support the idea that distinctiveness and emotional factors are important in memory.
Brown and Kulik suggested that a special neural mechanism might have been responsible for flash bulb memories. Other psychologists have suggested that flashbulb memories are so memorable because they are repeated so often, on occasions when people recall these emotionally significant lifetime events.