Flashcards in Individual Behaviour: Memory Deck (28):
The biological approach explains behaviour based on measurable features, such as brain waves and the physical structure of the brain.
The case study of Clive Wearing suggests that there is a difference in the storage of different types of memory. Clive Wearing suffered from a virus, which severely damaged his hippocampus. This has left him with very limited short-term memory, which leaves him unable to transfer new information to long-term memory. He also has limited ability to retrieve declarative memory (memory of things e.g. skills like playing an instrument, driving, people’s names etc.). His case may indicate that there is a difference in the storage in long-term memory between episodic and semantic memory. For example, he cannot remember any event in the past involving his wife (episodic), he does know that he loves her (semantic).
Clive Wearing also has strong procedural or process memory (memory of skills). For example, he can play the piano although he cannot remember how he learned and does not recall when he last played.
The case of study HM (Scoville and Milner, 1957) involved a sufferer from epilepsy having an operation to remove to remove part of his hippocampus. This led to an improvement in his epilepsy, but left him with severe problems in recalling declarative memory or to learn new skills, which indicates that procedural memory does not rely on the hippocampus.
Unusually for the brain, new neurons can be created in the hippocampus: Maguire et al (2000) showed that London taxi drivers, who need to recall a vast number of different routes, has enlarged hippocampi, indicating that the number of neurons increased as the amount of information contained in their long-term memory increased.
According to Hebb (1949), people learn through the connections (synapses) between neurons (nerve cells) becoming strengthened. This is called long-term potentiation – each time we recall a piece of information, we are strengthening that neural pathway, and this explains why practising a skill or repeatedly recalling a piece of information leads to us having a greater memory for it. This is consistent with Craik and Lockhart’s (1972) theory that depth of processing determines how well memory can be recalled: it can be understood that deeper processing strengthens the neural connection.
The average human brain has about 85 billion neurons, with about 100 trillion protentional connections between them (Zimmer 2011), which supports the hypothesis that long term memory has unlimited capacity.
Short-term memory or working memory is thought to depend on the prefrontal cortex in the brain. This is where the central executive of Baddeley and Hitch’s Working Memory Model is likely to be found. If the Multi Store Model is correct, then it would have expected that the STM store would be in the PFC. However, human brain imaging as well as research on monkeys’ learning by Lara and Wallis (2014) has suggested that, although the PFC has some role in short-term or working memory, the actual storage of short-term memory happens in posterior sensory areas.
Different stages of sleep seem to be important for consolidation of different types of memory. Stages 3 and 4 (deep, slow wave sleep) are associated with consolidation of declarative memory (Walker, 2009), which indicates that sleeping soundly on school nights is beneficial to retaining memory of information learned during the day. On the other hand, Nishida and Walker (2009) showed that a lunchtime nap 60-90 minutes enhanced the storage of newly learned procedural memories.
Biological Approach: Strengths
Scientific evidence available from brain imaging and brain waves. Detailed evidence available from case studies, e.g. Clive Wearing and HM. It is objective. By treating humans, the same as any other organisms, the data is not contaminated by cultural or differences which may affect people.
Biological Approach: Weaknesses
Frequently, research relies on case studies of brain damaged patients. These may be unique cases, and we may need to be cautious before generalising from them. Ignores the efforts of strategies that people may use to improve memory. The min is an abstract concept which is not the same as the physical brain. Anything that cannot be clearly explained in physical terms may be outside the scope of the biological approach.
Explains behaviour in terms of how our mind (rather than the physical brain) processes input from the senses to produce an output. It is often described as an information processing approach: it begins by analysing input from our sense; coding the information for storage and then creating an output when memory is to be retrieved.
Using the analogy of computer, long-term memory is like 1000TB hard drive, which can store an almost unlimited amount of information, potentially forever. Working or short-term memory operates like the computer processor, where there is a trade-off between speed and power, i.e. like the computer, we can process small amounts of information more quickly than large amounts.
We store and recall memory schemas. Allport and Postman (1947) and Loftus and Palmer (1974) both show how schemas are not always reliable. Often, we will construct a memory according to our existing schema of what the situation should be (e.g. white participants in Allport and Postman ‘remembered’ a black man threatening a white one, when the truth was the other way around); participants in Loftus and Palmer ‘remembered’ a car crash differently depending on the verb used when they were questioned about it. One weakness of the cognitive approach is that it relies on what participants tell the researcher rather than the kind of objective measurements which the biological approach benefits from. For example, the effects from both Allport and Postman and Loftus and Palmer could have been the result of conformity, and participants altering what they said to fit their listeners’ perceived expectations, although Loftus and Palmer attempted to control for this by adding the additional condition of asking participants about broken glass.
Bartlett (1932) showed that memory is ‘reconstructed’ rather than ‘replayed’ through Reconstructive Memory Theory. The participants in his study were students at Cambridge University and they were found to alter their re-telling of The War of the Ghosts in three ways: Assimilation – they changed features to understand it in terms of their own culture; Levelling – they made the story shorter and, finally, Sharpening – they added details in the story and the order of events so that it fitted better their own expectations. This strongly suggests that learning and retaining new material depends on how well it conforms to our existing schemas.
These studies are all relevant to the cognitive approach, because they suggest that at all three stages – analysis, storage and output – the processing of the information in terms of what we expect it to be is crucial to what we recall.
The cognitive approach can be applied to both the Multi Store Model and the Working Memory Model. The MSM shows information flowing sequentially from input to storage, and then from storage to output. A weakness of this, is that it does not take account of the possibility that different types of memory are stored different ways. It also doesn’t take explain the role of existing memories, or schemas, and how these might affect the acquisition of new learning. The Working memory model shows how different types of input can be processed in different ways. Like the MSM, it shows memory formation and recall as part of a process from input to output.
Brewer and Treyens (1981) showed a group of university students an office, in which there were typical office items, and some atypical items (e.g. a skull). Most participants recalled correctly the items that would be expected to be in an office (e.g. a computer); many recalled the atypical ones and some atypical ones and some recalled items indicates that at least some participants made use of existing schemes to refer to. A weakness, however, it that it is difficult to tell which of typical office items were recalled because they fitted schema and which were recalled in some other way. The fact that more typical than atypical items were recalled does suggest that participants were referring to schemas: however, ageing, there is the possibility that the participants were conforming to expectations to some extent. Perhaps participants did not report seeing, for example, the skull because they did not wish to be exposed to ridicule if they were wrong.
Cognitive Approach: Strengths
Explains how schemas can affect how memory is recalled. E.g. Loftus and Palmer. Demonstrates how schemas can be used to develop strategies to improve recall, e.g. through chunking information in STM (Miller 1956).
Cognitive Approach: Weaknesses
May have limited generalisability because recall depends on individual’s schemas. Does not take account of the effect of illness/ genes on the ability to recall (perhaps some individuals do have naturally better memories than others). It is unclear exactly what a schema is, or how they are created.
Concerned with the working of the unconscious mind, especially the interactions between the id, ego and superego. Memories, particularly those from early childhood, can be repressed so that we are not consciously aware of them. However, these can continue to influence our thoughts and behaviour. For example, the case of Little Hans involved a boy who had developed a fear of horses because unconsciously they reminded him of his father and because of the shock he had experienced when a horse collapsed in the street. The case of Wolf Man involved a man who suffered depression and physical symptoms because of a repressed memory of seeing his parents engaged in coitus.
Defence mechanisms can repress or distort memories which would otherwise be harmful to us, as in the case studies above. The defence mechanisms are caused by the ego trying to protect us from feelings of anxiety or guilt caused by the superego, from the desires of the id. Sometimes, defence mechanisms can lead to neuroses, such as phobias, caused by repressed memories which the mind has not properly come to terms with.
Unconscious memories can be brought into conscious, analysed and problems dealt with, via dream analysis; free association or transference (where the therapist will take on the role of the cause of the anxiety).
Examples of defence mechanisms are:
Repression – Pushing unwanted memories, truths, feelings and emotions into the unconscious mind.
Denial – Refusing to accept the truth.
Displacement – Choosing a substitute object for the expression of your true feelings because you can’t express them to the real target. You can also have displacement activity where you do something else instead of what you need to be doing.
Psychoanalytic Approach: Strengths
Looks for the root causes of behaviour and takes account of unconscious drives which may be influencing us. Provides evidence for how and why childhood memories can influence later behaviour. Provides reasons for how and why we may have repressed certain memories.
Psychoanalytic Approach: Weaknesses
Lack of research evidence. Depends on unique case studies, which cannot be generalised. Parkin et al (1982) argue that the psychoanalytic does not contribute anything which cannot be explained through other theories of memory.
Theories and Studies: Multi-Store Model of Memory Theory
Multi-Store Model (MSM) Memory
• Theory of Memory by Atkinson and Shiffrin.
• Memory consists of three separate stores. These are three separate structures in the brain.
• Receives input from our senses.
• Memory lasts less than half a second unless we pay attention to it, if we pay attention it is passed on to the next stage.
• Receives input from sensory store.
• Has capacity of 7±2 items (Miller 1956).
• Lasts about 18 seconds (Peterson and Peterson 1959).
• Can be increased by chucking.
• Memory is stored acoustically (by sound).
• If we rehearse, it is passed on to the next stage.
• Receives input from short-term memory.
• Has unlimited capacity and duration.
• Memory is stored semantically (by meaning).
Theories and Studies: Multi-Store Model of Memory Theory - Strengths
The case Clive Wearing supports idea of separate stores. This because at least part of his LTM is still intact (so he can play the piano and recognise his wife), but the STM store does not seem to work (forgets things very quickly). It is supported by the primacy and recency effect (Glanzer and Cunitz, 1966). This shows that we are generally able to recall best the first and last in a list, but not the middle items. This may be because the first items have passed into LTM; the last items are still in STM, but the middle items do not get rehearsed and are displaced by later items.
Theories and Studies: Multi-Store Model of Memory Theory - Weaknesses
The MSM does not explain why we sometimes remember things without rehearsal. It assumes that we remember all types of information in the same ways. Although there is considerable evidence for the storage of information semantically in LTM, it seems likely that not all information is processed acoustically in STM.
Theories and Studies: Working Memory Model Theory
This model was devised by Baddeley and Hitch (1974) and instead of short-term memory there is a central executive. This controls attention and controls 2 ‘slave systems’ – the Visuo-spatial scratchpad (inner eye) and phonological loop.
The phonological loop processes auditory information. It has 2 parts: the phonological store and the articulatory loop.
The phonological store (inner ear) receives auditory information: can only store this for 2 seconds, we know this because of Baddeley et al (1975).
The articulatory loop (inner voice) allows auditory information to be rehearsed. We know this because of Trojano and Grossi (1995) where a brain-damaged patient had good learning abilities, but could not remember word-pairs when they were said out loud. This suggests damage to the articulatory loop.
The visuo-spatial sketchpad (inner eye) processes visual information as shapes sizes, colours etc. We know this because of Baddeley et at (1975) where participants who were given 2 visual tasks. This suggests that the visual and verbal tasks were processed differently in the brain.
Theories and Studies: Working Memory Model Theory - Strengths
Supports Paivio’s Dual Coding Theory, i.e. are processed in different ways, and different modes (e.g. acoustic/ visual) don’t necessarily interfere with each other. Baddeley (1975) demonstrated word length effect. This showed that working memory capacity is not necessarily restricted to 7±2: rather, the amount of time taken to process the information, therefore are less likely to recall as much. It fits the biological approach, in that the central executive can be assumed to be in the prefrontal cortex which has been found to be linked closely to the processing of working memory. Gathercole and Baddeley (1990) showed that, where children had a deficit in their phonological loop (i.e. they struggled to hold the auditory information), this was linked to problems of language development.
Theories and Studies: Working Memory Model Theory - Weaknesses
It is not entirely clear precisely what the central executive is, or what its capacity it has.
Theories and Studies: Reconstructive Theory of Memory
Bartlett – our memory is not like a DVD, where we can play events back just as they happened.
• We try to reconstruct memories, based on what we think probably happened; what we would have expected to happen, etc.
• We are influenced by schemas – a schema is like a stereotype, where we have an internal view of what something should be like. So, if your schema of a car crash involves ‘broken glass’, you may ‘remember’ broken glass even if there was none there.
• When participants were asked to memorise the (Native American) story The War of the Ghosts, he discovered that they altered parts of it to ‘make sense’ with their own schemas. This suggests that eyewitness testimony may be unreliable where there is a cultural difference between the witness and the accused.
• Allport and Postman (1947) – when shown an image of a white man holding an open razor and confronting a black man, most black participants remembered it correctly. This suggests that the white participants reconstructed the memory to fit their schemes – they expected the black man to be more likely to acting aggressively. On the other hand, the black participants, perhaps having experienced racism from white people, didn’t have the same expectations.
• Loftus and Palmer (1974) – participants who had witnessed a fake car crash altered their estimates of the speed that cars had been travelling at depending on the verb in the questions they were asked.
Theories and Studies: Reconstructive Theory of Memory - Strengths
Supported by reseach; Allport and Postman and Loftus and Palmer.
Theories and Studies: Reconstructive Theory of Memory - Weaknesses
Whether participants who alter their views to fit the social expectation of society (Allport and Postman) or a questioner (Loftus and Palmer) are recalling the information wrongly, or whether this is due to conformity due to the participant feeling embarrassed about being ‘wrong’ and are trying to give the researcher the answer they think they want.
Theories and Studies: Trace Decay Theory (Theories of Forgetting)
• We remember things because memories have a physical trace in our brain.
• In STM, the trace decays very quickly if information Is not rehearsed. This would explain the findings of Peterson and Peterson (1959): i.e. that memory decays very quickly as the trace disappears.
• In LTM, trace decay theory doesn’t so well. We can remember some things very clearly, whilst forgetting others. Lashley (1931) found that rats who had learned their way through mazes, then had parts of their brains removed, ‘forgot’ part or all of what they had learned. This is evidence for LTM forgetting being related to physical decay. However, remember the Bahrick et al experiment. This suggests that there can be very strong memory traces over a very long period. Baddeley and Hitch (1977) found evidence that forgetting in LTM has more to do with interference.
Theories and Studies: Displacement Theory (Theories of Forgetting)
• In STM, the recency effect (Glanzer and Cunitz) could be result of more recent information displacing (pushing out) older information.
• If the capacity of STM is limited (Miller), then when it becomes ‘full’, any new information can simply displace any older information.
• Waugh and Norman (1965) – participants were read a list of digits to remember, either quickly or slowly. If decay was responsible for forgetting, they would forget more of the slow list than the quick list. Although a small amount of decay was found, the biggest difference was due to displacement. This is shown by a strong recency effect in both cases, yet little difference between the 2 conditions.
• Since LTM is unlimited in capacity, displacement ought to have no meaning in LTM.
Theories and Studies: Interference Theory (Theories of Forgetting)
• Proactive interference – earlier learning interferes with new learning
• Retroactive interactive – new learning interferes with older learning
Tulving and Psotka (1971) – participants were asked to learn a list of words which were in categories (e.g. animals, colours). Those who were only given a few categories remembered more words than those who had many categories. This suggested that the later categories interfered with the earlier ones. However, when the participants were also given category names, the number of words recalled increased no matter how many categories they were given.
Baddeley and Hitch (1977) – rugby players were asked at the end of a season to recall matches their team had played. They discovered that the players who had played in the most matches had forgotten proportionally more than players who had missed matches through injury. This suggests that the amount of information (playing in more matches) had led to interference.
Only applies to LTM. Forgetting in long-term memory is due to failure of retrieval, i.e. the information is ‘in there’, but you don’t have the right key to unlock it.
Theories and Studies: Cue Dependence and State Dependence (Theories of Forgetting)
• Abernethy (1940) – when students sat a test in their normal classroom with their normal classroom with their normal instructor performed better than those who sat the test in another room or with a normal instructor. This suggests that being in a familiar situation can provide cues which trigger a recall of memory.
• Goodwin et al (1969) – people who drank a lot often forgot where they had put things when were sober, but remembered them when they were drunk again. This provided a cue for them to recall.
• Godden and Baddeley (1975) – a group of expert divers were given a series of words to learn either (1) under water (2) on dry land. In each condition, the divers were asked to recall the words in (3) the same state in which they had learned them or (4) the opposite state. No matter where the divers had learned the words, they performed significantly better on recall when asked in the same condition as they had learned them.
Theories and Studies: Loftus and Palmer (1974)
Aim: To find out whether asking a leading question would cause participants to alter their estimates of how fast a car had been travelling prior to an accident.
Method: Experimental – laboratory.
Procedure: 24 university students were shown a film about a fake car crash. Each was then asked a question ‘how fast was the car going before the impact’ describing it as either ‘smashed’, ‘hit’, ‘collided’ or ‘contacted’.
Results: The more dramatic the verb used, the higher the estimate of speed that the participants tended to give. For example, ‘smashed’ elicited a higher estimate than ‘contacted’.
Conclusion: People recall information according to schemas. If a piece of information does not fit a schema, then people will unconsciously alter the memory to fit.
Theories and Studies: Loftus and Palmer (1974) - Strengths
The researchers attempted to address the concern of the participants conforming with a follow up experiment which asked participants 1 week later whether they had seen broken glass. The participants that were asked the more ‘dramatic’ question were more likely to ‘recall’ broken glass even though there was none. This indicates that the leading question does affect the schema when the memory is created.
Theories and Studies: Loftus and Palmer (1974) - Weaknesses
Participants may alter their answer to fit the expectation of a questioner, therefore, the effect may be due to conformity rather than a weakness. Also as this was a laboratory experiment the participants memories may be affected. When Yuille and Cutshall (1986) carried out a study with eyewitnesses to a real-life shooting, they found that the witnesses had a very good memory, even when presented with misleading questions.
Theories and Studies: Allport and Postman (1947)
Aim: To find out whether schemas would affect recall, specifically when recalling an image of a white man threatening a black man.
Method: Experimental – laboratory.
Procedure: Black and white Americans were both shown an image of a white man holding a razor and apparently threatening a black man. The black man was more smartly dressed and the white man was displaying more aggressive gestures. Apart from their race, there was nothing in the picture to suggest that the white man was not the aggressor. Participants then told the story to each other.
Results: As the white participants told the story to each other, the black man quickly became the aggressor. With the black participants, the white man was still the aggressor.
Conclusion: People recall information according to schemas. If a piece of information does not fit a schema, then people will unconsciously alter the memory to fit.
Theories and Studies: Allport and Postman (1947) - Strengths
The white participants may have had a schema that black men were more likely to be aggressive and/ or more likely to commit crime, so changed the story to fit their schema. The black participants may have experienced racism at the hands of whites and so their schema was not that blacks were more aggressive.