Memory Flashcards
What is memory?
Memory is the process by which we retain and recall information about events that have happened in the past.
What is coding?
The format in which information is stored in the memory stores. It’s the process of converting information from one format to another.
What is capacity?
The amount of information that can be stored.
What is duration?
The length of time information can be held in the memory store
According to Jacobs, what is the capacity of STM? How did he study this?
Jacobs (1887) developed a technique to measure digit span. The researcher gives, for example, four digits and then the participant is asked to recall these in the correct order out loud. If this is correct, the researcher reads out five digits, and so on until the participant cannot recall the order correctly. This determines the individual’s digit span. Jacobs found that the mean span for digits across all participants was 9.3 items. The mean span for letters was 7.3.
According to Miller, what is the capacity of STM?
From a review of psychological research, Miller (1956) found that the span (capacity) of human memory is about 7 items (plus or minus 2). People cope well with counting 7 flashing dots but not much more – same for digits, numbers and even words. He also noted that people can recall 5 words as easily as 5 letters. They do this by chunking – grouping sets of letters or digits into units or chunks.
What is the capacity of LTM?
Potentially unlimited
Evaluate research into the capacity of memory in at least two ways
Jacobs - However, Jacobs’ study was conducted a long time ago. Early research in Psychology often lacked adequate control. For example, some participants may have been distracted while they were being tested so they didn’t perform as well as they might. This would mean that the results might not be valid because there were confounding variables that weren’t controlled. Therefore, we can’t be certain that the results are a valid reflection of the capacity of STM. However, the results have been supported in other research, supporting its validity.
Miller - However, he may have overestimated the capacity of STM. Cowan (2001) reviewed other research and concluded that the capacity of STM was only about four chunks. This suggests that the lower end of Miller’s estimate (5 items) is more appropriate than 7 items.
What did Peterson and Peterson do and find?
Aim: To investigate the duration of short-term memory and provide empirical evidence for the multi-store model.
Procedure: A lab experiment was conducted in which 24 undergraduate students took part in 8 trials (8 tests). On each trial they were given a consonant syllable or trigram (meaningless three-consonant syllables, e.g. TGH) to remember and a three-digit number. The student was then asked to count backwards from the number in either 3s or 4s until told to stop. The counting backwards was to prevent any mental rehearsal of the consonant syllable (which would increase the student’s memory). On each trial, they were told to stop after a different amount of time - 3, 6, 9, 12, 15 or 18 seconds. This is called a retention interval. After this, they were asked to stop counting and to repeat the trigram. The percentage of trigrams correctly recalled was recorded for each retention interval.
Findings: The longer the interval delay the less trigrams were recalled. Participants were able to recall 80% of trigrams after a 3 seconds delay. However, after 18 seconds less than 10% of trigrams were recalled correctly.
What did Peterson and Peterson conclude the duration of STM is?
Information must be rehearsed in order to keep it in STM. Short-term memory has a limited duration (up to 18 seconds) but in the exam we can say up to 30 seconds, when rehearsal is prevented. The results of the study also show the short-term memory is different from long-term memory in terms of duration.
What did Bahrick et al. do and find?
Aim: To investigate the duration of LTM.
Procedure: Participants were an opportunity sample of 392 American ex-high school students aged 17-74 years. High school yearbooks were obtained from the participants directly or from some schools. Recall was tested in various ways, including: (1) free recall test - where participants recalled the names of as many of their former classmates as possible; (2) photo recognition test - where they were asked to identify former classmates in a set of 50 where some were from their yearbook and some weren’t.
Findings: Participants who were tested within 15 years of graduation were about 90% accurate in photo recognition. After 48 years, recall declined to about 70% for photo recognition. Free recall was less good. After 15 years, this was about 60% accurate, dropping to 30% after 48 years.
What did they conclude the duration of LTM is?
LTM has a seemingly unlimited duration.
Evaluate research into the duration of memory in at least two ways
Peterson and Peterson - a limitation of this is that the stimulus material was artificial. Trying to memorise consonant syllables does not reflect most real-life memory activities where what we are trying to remember is meaningful. So we might say that the study lacked external validity and may therefore underestimate the duration of STM for more realistic information. However, we do sometimes try to memorise fairly meaningless things e.g. phone numbers, so the study is not totally irrelevant and may tell us something about the duration of STM in these circumstances.
Bahrick et al - this study has higher external validity as real-life memories were studied. When studies on LTM have used meaningless pictures, recall rates were lower. Therefore the study seems to tell us about the duration of LTM with realistic tasks. The downside of such real-life research is that confounding variables are not controlled e.g. participants may have looked at their yearbook photos and rehearsed their memory over the years. Therefore, the study lacks internal validity and we can’t be certain that the results reflect the true duration of LTM without rehearsal.
How did Baddeley study the coding of STM and LTM? What did he find?
Baddeley (1966) gave different lists of words to four groups of participants to remember:
Group 1 – acoustically similar – words that sounded similar e.g. cat, cab, can
Group 2 – acoustically dissimilar – words that sounded different e.g. pit, few, cow
Group 3 – semantically similar – words with similar meanings e.g. great, large, big
Group 4 – semantically dissimilar – words with different meanings e.g. good, huge, hot
Participants were shown the original list of words and asked to recall them in the correct order. When they had to do this recall task immediately after hearing it (STM recall), they tended to do worse with acoustically similar words. This suggests that information is coded acoustically in STM.
If participants were asked to recall the word list after a time interval of 20 minutes (LTM recall), they did worse with the semantically similar words. This suggests that information is coded semantically in LTM.
What did he conclude about the coding of STM and LTM?
STM is coded acoustically
LMT is coded semantically
Evaluate research into the coding of memory in (just Baddeley)
The study used quite artificial stimuli rather than meaningful material. The word lists had no personal meaning to participants. This means that we should be cautious about generalising the findings to different kinds of memory task e.g. when processing more meaningful information, people may use semantic coding even for STM tasks. This suggests that the findings from this study have limited application about the coding of STM and LTM.
What is the Multi-Store Model of Memory (MSM)?
A structural model (representation) of memory. It was the first complex model of human memory. They suggest that each store is different/separate (unitary) and information is transferred from one store to another in a fixed, linear sequence.
What is meant by a unitary store and how many are there according to the MSM?
It means different or seperate. The MSM is made up of three
What is the sensory register?
The sensory register is the memory stores for each of our five senses e.g. iconic store for visual information, echoic store for sound information.
What is the coding, capacity and duration of the sensory register?
Coding - each store of the sensory register are coded differently (iconic coded visually, echoic coded acoustically etc.).
Capacity - high capacity e.g. over one hundred million cells in one eye
Duration - less than half a second
According to the MSM, how is information transferred from the sensory register to STM?
If you pay attention to it
According to the MSM, how is information transferred from STM to LTM?
Prolonged rehearsal
According to the MSM, how is information transferred from LTM to STM?
Retrieval
What are the strengths of the MSM?
Supporting evidence from previous studies
Supporting evidence - Baddeley’s study - supports that STM and LTM are coded differently which supports that they are unitary
Supporting evidence - Peterson and Peterson found that duration of STM is up to 30 seconds without rehersal and Bahrick et al. Found that the duration of LTM is up to a lifetime which supports that they are unitary (separate)
What are the weaknesses of the MSM?
Weaknesses of the supporting evidence
Weakness - Baddeley and Peterson and Peterson used artificial stimuli –> not externally valid, so they are not very strong support for the idea that the STM and LTM are unitary stores
Weakness - There may be actually more than one type of LTM but the model suggests that it is all one unitary store
What happened to HM? How does his case both support and undermine the MSM?
HM underwent brain surgery to relieve his epilepsy which involved removing his hippocampus. When his memory was assessed in 1955 (when he was 31), he thought it was 1953 and he was 27. His LTM was tested over and over again but never improved with practice. He would read the same magazine repeatedly without remembering it. He couldn’t recall what he had eaten earlier the same day. However, he performed well on tests of immediate memory span (a test of STM e.g. Star task).
This supports that STM and LTM are two unitary stores that are qualitatively different because one can be damaged whilst the other remains intact, as proposed by the MSM. They may even be stored in different parts of the brain. Counterargument: however, the research was a unique case study of a brain damaged individual. You need to explain how.(not a lot of people had a brain injury exactly like his) Therefore, it isn’t particularly strong support for the MSM as the results may not be generalisable to other people (you need to explain who) (people who haven’t had the surgery/ had their memory affected like he had)
What happened to KF? How does his case undermine the MSM?
Shallice and Warrington (1970) studied a patient with amnesia called KF. They found that his STM for digits was very poor when they were read out loud to him, but his recall was much better when he was able to read them to himself. Further studies of KF and other people with amnesia suggest that there could be another short-term store for non-verbal sounds.
This is a limitation of the MSM because research suggests that there must be at least one short-term store to process visual information and one to process auditory information, which undermines the unitary store of STM proposed by the MSM. The working memory model includes these separate stores of STM. (when we have done the WMM you will be able to say what these stores are and how therefore the WMM may be a better model of STM than the MSM)
What did Craik and Watkins suggest about rehearsal? How does this undermine the MSM?
Ignore
According to the MSM, it’s the amount of rehearsal that matters. Craik and Watkins (1973) found that there are actually different types of rehearsal. There are two main types: maintenance rehearsal (as described in the MSM) and elaborative rehearsal which is needed to transfer information from STM to LTM. Elaborative rehearsal is when you link the information into your existing knowledge, or you think about what it means.
This is a serious limitation of the MSM because it is another research finding that cannot be explained by the model. This suggests it may not be a completely valid model of how memory works.
What happened to Clive Wearing? How does his case undermine the MSM?
There is lots of evidence that there is more than one type of LTM. Clive Wearing suffers from a severe form of amnesia that resulted from a viral infection that attacked his brain, damaging the hippocampus and associated areas. Before this infection, Clive was a world-class musician and he can still play the piano brilliantly and conduct a choir but he can’t remember his musical education. He can remember some other aspects of his life before his infection, but not others. For example, he knows he has children from an earlier marriage, but cannot remember their names. He recognises his second wife, Deborah, and greets her joyously every time they meet, believing he has not seen her in years, even though she may have just left the room for a few minutes. He has no problem understanding the meaning of words and can carry out a conversation effectively.
This is a limitation of the MSM because research suggests that there must be at least one long-term store to store our knowledge of the world and one to store our knowledge of how to do things, which undermines the unitary store of LTM proposed by the MSM.
Name and define the three types of LTM according to Tulving.
Episodic - memories of life events. Can be expressed verbally (recalled with conscious effort) – available for conscious inspection (explicit). Time-stamped – with reference to time and place. May be less resistant to amnesia/forgetting
Semantic - memories of knowledge of the world. Can be expressed verbally (recalled with conscious effort) – available for conscious inspection (explicit). Not time-stamped. May be less resistant to amnesia/forgetting
Procedural - memories of how to do things (motor skills/actions). Difficult to explain verbally (recall without conscious awareness) – unavailable for conscious inspection (implicit). Not time-stamped. May be more resistant to amnesia/forgetting
Which types of LTM were intact and damaged for Clive Wearing? How does this support the types of LTM?
His procedural memory is intact because he can still play the piano and conduct a choir.
His episodic memory is impaired because he can’t remember having seen his wife recently…
His semantic memory is partly intact because he can remember his wife’s name and the meaning of lots of words, but he can’t remember his children’s names.
This supports Tulving’s view that there are different memory stores in LTM. One store can be damaged but other stores are unaffected. This is clear evidence that nor only are there different types of LTM, but that they are stored in different parts of the brain.
Counterargument: the evidence is based on unique case studies of brain damaged individuals. Therefore, the research isn’t strong support for the different types of LTM
What did Tulving et al. Do and find? How does this support the types of LTM?
Brain scans
There is evidence from brain scan studies the different types of memory are stored in different parts of the brain. Tulving et al. (1994) got their participants to perform various memory tasks while their brains were scanned using a PET scanner. They found that episodic and semantic memories were both recalled from the prefrontal cortex. The left prefrontal cortex was involved in recalling semantic memories. The right prefrontal cortex was involved in recalling episodic memories.
This supports the view that there is a physical reality to the different types of LTM within the brain. It has also been confirmed many times in later research studies, further supporting the validity of this finding.
What real-world application is there of knowing that there are different types of LTM?
Being able to identify different aspects of LTM allows psychologists to target certain kinds of memory in order to better people’s lives. Research has found that episodic memories could be improved in older people who had a mild cognitive impairment. The trained participants performed better on a test of episodic memory than a control group. Episodic memory is the type of memory most affected by mild cognitive impairment, which highlights the benefit of being able to distinguish between types of LTM – it enables specific treatments to be developed, supporting the external validity of the theory.
Other people have disagreed that there are three LTM stores. What do they propose instead and how is this a weakness of the types of LTM?
They accept that procedural memories represent one type of LTM. But they argue that episodic and semantic memories are stored together in one LTM store that they call declarative memory (i.e. memories that can be consciously recalled). Procedural memories are non-declarative. It is important to get these distinctions right so that any treatments that are developed are effective and so that the theory is valid i.e. it accurately explains the differences between types of LTM.
What is the working memory model (WMM) a representation of?
The working memory model (WMM) is a representation of how short-term memory is organised and how it functions. It was proposed by Baddeley and Hitch in 1974 as an updated version of STM. It suggests that STM is an active processor of different types of information using sub-units that are coordinated by a central decision-making system.
How is the WMM different to the MSM in how it represents this type of memory?
The MSM represents a simplified version of STM whereas the WMM consists of four main components which are qualitatively different in terms of their capacity and coding
Describe the function, coding and capacity of the central executive
Function: coordinates activity of the three slave systems. Takes in information from senses and LTM, makes decisions and allocates slaves systems to tasks.
Capacity: Limited processing; no storage
Coding: Any sensory modality
Describe the function, coding and capacity of the phonological loop
Function - processes and temporarily stores sound based information and preserves order they arrive in
Capacity - 2 seconds
Coding - acoustically
Subcomponents: Phonological store: stores sound based information (words you hear)
Articulatory process: maintenance rehearsal (inner voice)
Describe the function, coding and capacity of the visuo-spatial sketchpad
Function - processes and temporarily stores visual and spatial information (what you can see and where things are in relation to each other)
Capacity - 3/4 objects
Coding - visual
Subcomponents: The visual cache – which stores visual info - The inner scribe – which records the arrangement of objects in the visual field (spatial info).
Describe the function, coding and capacity of the episodic buffer
Note: added later (2000)
Function: integrates information from other slave systems and central executive into a single memory with time sequencing. Also sends information to LTM
Capacity: about 4 chunk
How does the case of KF support the WMM?
Shallice and Warrington’s (1970) case study was of a patient, KF, who had suffered brain damage. After this damage, KF had poor STM ability for verbal information, but could be process visual information i.e. he had difficulty with sounds but recall letters and digits shown to him. This suggests that just his phonological loop had been damaged leaving other areas of memory intact. This supports the existence of a separate visual and acoustic store. Counterargument: however, evidence from brain-damaged patients may not be reliable because it concerns unique cases with patients who have had traumatic experiences. Therefore, the results may not generalise to others and so can’t provide strong support for the WMM.
What happens in dual-task studies? How do they support the WMM?
Studies of dual-task performance support the existence of the visuo-spatial sketchpad. Baddeley et al. (1975) found that participants had more difficulty doing two visual tasks (tracking a light and describing the letter F) than doing a visual and verbal task at the same time. This increased difficulty is because both visual tasks compete for the same slave system, whereas when doing a verbal and visual task simultaneously, there is no competition. It supports that the slave systems have a limited capacity and so when multiple tasks require the same slave system (e.g. Two visual tasks) then this exceeds the capacity of the slave system making the tasks harder. Whereas, when doing tasks that require two different slave systems, the tasks are easier as they don’t exceed the capacities of either system. As such, this supports that there must be one slave system for processing visual input (visuo-spatial sketchpad) and one for processing sound input (phonological loop) as proposed by the WMM.
What did Braver et al. do and find? How does this support the WMM?
Braver et al. (1997) gave their participants a task that involved the central executive while they were having a brain scan. They found greater activity in the prefrontal cortex and that this activity increased as the task got harder. This makes a lot of sense in terms of the WMM – as the demands on the central executive increase, it has to work harder to fulfil its function. This supports the existence of the central executive as a supervisory component as proposed by the WMM.
Which component of the WMM do psychologists think is unsatisfactory and why? What does this tell us about the WMM?
Cognitive psychologists suggest that the central executive is unsatisfactory and doesn’t really explain anything. Baddeley himself recognised that the central executive is the most important but least understood component of the WMM. It needs to be more clearly specified than just being simply ‘attention.’ For example, some psychologists believe it may consist of separate components. This means that the WMM hasn’t been fully explained.
What is interference?
Interference is where two lots of information become confused in memory. One memory disrupts/affects another, causing one or both of the memories to be forgotten or distorted. It is mainly an explanation of forgetting in LTM.
What is proactive interference?
Where old learning/memories affect the recall of new information.
What is retroactive interference?
Where new learning/memories affect the recall of old information.
Does forgetting occur because the memory isn’t available or isn’t accessible according to this theory?
The memories are available just not accessible
When is interference more likely to occur?
If the competing information is similar.
What did McGeoch and McDonald do and find?
They studied retroactive interference by changing the amount of similarity between two sets of materials. Participants had to learn a list of 10 words until they could remember them with 100% accuracy. They then learned a new list. There were six groups of participants (independent groups) who had to learn different types of lists:
Group 1 – synonyms – words with the same meanings as the originals
Group 2 – antonyms – words with the opposite meanings as the originals
Group 3 – words unrelated to the original list
Group 4 – nonsense syllables
Group 5 – three-digit numbers
Group 6 – no new list – these participants just rested
When the participants then recalled the original list of words, their performance depended on the nature of the second list. The most similar material (synonyms) produced the worst recall. This suggests that interference is strongest when the memories are similar.
Which parts of interference theory does McGeoch and McDonald’s study support and how?
This supports that new information affects the ability to recall old information as predicated by retroactive interference. It also supports that the more similar the memories, the more likely interference is, and he greater the forgetting. Therefore, this supports the validity of interference theory as an explanation of forgetting.
What did Baddeley and Hitch find?
Baddeley and Hitch (1977) asked rugby players to try to remember the names of the teams they had played so far in that season, week by week. Because most of the players had missed games, for some the ‘last team’ they played might have been two weeks ago or three weeks ago or more. They found that accurate recall did not depend on how long ago the matches took place. Much more important was the number of games they had played in the meantime. So a player’s recall of a team three weeks ago was better if they had played no matches since then.
This supports that interference explanations can apply to forgetting in at least some everyday situation.
Which parts of interference theory does Baddeley and Hitch’s rugby players study support and how?
Retroactive interference as the new memories of the more recent teams played is affecting the recall of the older memory of the past teams played
Describe a study that supports proactive interference
Tulving and Psotka (1971) gave participants lists of words organised into categories, one list at a time (participants were not told what the categories were). Recall averaged about 70% for the first list but became progressively worse for each list as they learned each additional one (proactive interference). This suggests that forgetting can occur because of proactive interference as the information on the first list disrupted the ability to recall the information on the later lists, supporting the validity of interference theory as an explanation of forgetting.
The studies to support interference theory are laboratory experiments. Why could this be considered both a good thing and bad thing when investigating interference?
Ignore
Lab experiments offer control over potential extraneous variables [you’d need to include an example here] and so gives us confidence that interference is a valid explanation for at least some forgetting.
Define retrieval failure
A form of forgetting. It occurs when we don’t have the necessary cues to access memory. The memory is available but not accessible unless a suitable cue is provided.
What is the encoding-specificity principle?
It argues that for a cue to be helpful in recall, it has to be present at encoding and retrieval. If the cues at encoding and retrieval are different, or the cues are completely absent at retrieval, there will be some forgetting.
What is context-dependent forgetting?
Being in a different place at recall may inhibit memory. The external cues available at learning (encoding) are different from those at recall which leads to retrieval failure. E.g. classroom vs exam hall.
What is state-dependent forgetting?
Being in a different mood/state of arousal at recall may inhibit memory. The internal cues at learning (encoding) are different from those at recall, which leads to retrieval failure. E.g. drunk vs sober.
According to the encoding-specificity principle, when will we forget?
When the cues are absent or different at retrieval than encoding
According to retrieval failure theory, do we forget because the memory is unavailable or inaccessible?
Inaccessible
What did Godden and Baddeley do and find?
They carried out a study of deep-sea divers working underwater. In this study, the divers learned a list of words either on land or underwater, and then were asked to recall the words either on land or underwater. This therefore created four conditions:
Learn on land – recall on land
Learn on land – recall underwater
Learn underwater – recall on land
Learn underwater – recall underwater
The conditions where the place of learning (encoding) and recall (retrieval) don’t match i.e. Conditions 2 and 3 will experience more forgetting.
Which parts of retrieval failure theory does this support and how?
And percentage that recall was worse when the cues didn’t match
This is because of context-dependent forgetting because the place is the cue and it is different at encoding and retrieval, meaning participants will experience forgetting. Recall was found to be 40% worse when the cues at encoding and retrieval did not match.
What did Godden and Baddeley then change the memory task to? What did they then find and why is this a problem for the theory?
The context effect may be related to the kind of memory being tested. Godden and Baddeley (1980) replicated their underwater experiment but used a recognition test instead of recall. Participants had to say whether they recognised a word read to them from the list, instead of having to retrieve it themselves. When recognition was tested there was no context dependent effect; performance was the same in all four conditions.
This suggests that the study can’t provide very strong support for the retrieval failure theory as the type of memory test used in the study may not generalise to all other situations. It also suggests that the presence or absence of cues only affects memory when you test it in a certain way, so the explanation isn’t a completely valid explanation of forgetting.
The effects of context-dependent forgetting are not thought to be as strong as it appears in Godden and Baddeley’s study. Why not and why is this a problem with using the study to support the theory?
Ignore
Baddeley argues that the context effects are actually not very strong, especially in real life. Different contexts have to be very different indeed before an effect is seen. For example – it would be very hard to find an environment as different from land as underwater. In contrast, learning something in one room and recalling it in another is unlikely to result in much forgetting because they environments are generally not different enough.
This suggests that retrieval failure due to the absence of contextual cues may not really explain much forgetting. It also means that the study can’t provide very strong support for the retrieval failure theory as the contexts in the study are too different to truly generalise to other situations.
What did Carter and Cassaday do and find?
They gave anti-histamine drugs (for treating hay fever) to their participants. These had a mild sedative effect, making the participants slightly drowsy. This creates a different internal state to the ‘normal’ state of being awake and alert. The participants learned lists of words and a passage of prose and then recalled the information. This was done in four conditions:
Learn on drug – recall on drug
Learn on drug – recall when not on it
Learn when not on drug – recall on drug
Learn when not on drug – recall when not on drug
The conditions where the internal state of mind is different at encoding and retrieval (i.e. Conditions 2 and 3) experience more forgetting
Which parts of retrieval failure theory does Carter and Cassaday’s study support and how?
State-dependent forgetting
Retrieval failure theory has useful real-world applications in improving the accuracy of eyewitness testimonies? How?
Ignore
It has been shown that eyewitness testimony can be improved using a technique called the cognitive interview. This technique has a number of stages, one of which is asking the eyewitness to reinstate the context by returning to the original crime scene in their mind, and imagine the environment (such as the weather, what they could see) and their emotions (such as what were their feelings) before asking them to recall what happened. The cognitive interview has been successful with many studies reporting an increase in correct information after use of the technique [you would then include the findings of a study from lesson 9 here]. Additionally, we can use the research to improve recall when we need to e.g. when taking exams. It may be unrealistic to learn the information in the exam hall, but research has shown that just thinking of the room where you did the original learning was as effective as actually being in the same room at the time of retrieval
This is a strength of the explanation because it suggests that knowledge of the explanation is useful in real-life situations, and therefore supports the external validity of the explanation.
Define eyewitness testimony
The ability of the person who saw the crime to remember the detail of the events they have observed. They provide this evidence in court, with a view to identifying the perpetrator. Their accuracy can be affected by factors such as misleading information and anxiety.
Define misleading information
Incorrect information given to an eyewitness after the event which affects the accuracy of their testimony. It can take many forms e.g. leading questions and post-event discussion between co-witnesses or other people
What are leading questions?
A question which because of its phrasing suggests a certain answer. This can then affect the accuracy of the EWT.
What is post-event discussion?
When there is more than one witness to the event, they may discuss what they have seen with each other or other people. This may influence the accuracy of their recall of the event. This is because the witness combines (mis)information from other witnesses with their own memories.
Describe the procedure, results and conclusion of Loftus and Palmer’s study of leading questions
They arranged for participants (students) to watch film clips of car accidents and then gave them questions about the accident. In the critical question (leading question), participants were asked to describe ‘how fast the cars were going when they hit each other?’ This is a leading question because the verb ‘hit’ suggests the speed the car was growing. There were 5 groups of participants. Each was given a different verb in the critical question. These were ‘hit’, ‘collided’, ‘contacted’, ‘bumped’ and ‘smashed.’
The mean estimated speed was calculated for each group. The mean estimated speed for contacted was 31.8mph and for smashed was 40.5mph. The leading question biased the eyewitnesses’ recall of the event.
According to Loftus and Palmer, what are the two possible reasons why leading questions decrease the accuracy of EWT?
Real world application
Loftus believes that leading questions can have such a distorting effect on memory that police officers need to be very careful about how they phrase their questions when interviewing eyewitnesses. Research into EWT is one area in which psychologists believe that they can make an important positive difference to the lives of real people e.g. by improving the way the legal system works and be appearing in court trials as expert witnesses.
A great strength of all of the research into misleading information is that it has hugely important practical uses in the real world where the consequences of inaccurate EWT can be very serious indeed. This therefore supports the external validity of the research on misleading information affecting EWT.
Describe the procedure, results and conclusion of Gabbert et al.’s study of post-event discussion.
They studied participants in pairs. Each participant watched a video of the same crime, but the crime was filmed from different points of view. This meant that each participant could see elements of the event that the other could not. For example, only one of the participants could see the title of a book being carried by a young woman. Both participants then discussed what they had seen before individually completing a test of recall.
The researchers found that 71% of the participants mistakenly recalled aspects of the event that they did not see in the video but had picked up in the discussion. The corresponding figure in the control group, where there was no discussion, was 0%.
According to Gabbert et al., why does post-event discussion decrease the accuracy of EWT?
Gabbert et al. concluded that witnesses often go along with each other, either to win social approval or because they believe the other witnesses are right and they are wrong. This is called memory conformity.
Loftus and Palmer’s study involved watching clips of accidents. Why is this a problem?
Ignore
Loftus and Palmer’s study involved watching film clips of accidents. This is a very different experience from witnessing a real accident, mainly because such clips lack the stress of a real accident. There is some evidence that emotions can influence on memory [when we have covered lesson 8, you will be able to add evidence to this about how anxiety affects memory to make this argument stronger].
This suggests that studies that use such artificial tasks may tell us very little about how leading questions affect EWT in cases of real accidents or crimes. It could even be that researchers are too pessimistic about the accuracy of EWT and it may be more reliable than the studies suggest.
The studies of EWT often use young people as confederates. Why is this a problem?
Ignore
There is evidence that older people are less accurate than younger people when giving eyewitness reports. Research has found that people in 18-25 and 35-45-year age groups are more accurate than the 55-78 year age group. However, all age groups were more accurate when identifying people own their own age.
As studies tend to use younger confederates as the target to identify, this may mean that some age groups appear less accurate when in fact this may not be true. Therefore, the studies may tell us little about the effects of misleading information on EWT.
When participants think they’re watching clips of real robberies and that their responses would influence the trial, their identification was much more accurate than in the studies we have learned. Why is this a problem?
This suggests that studies that use artificial tasks may tell us very little about how leading questions affect EWT in cases of real accidents or crimes. It could even be that researchers are too pessimistic about the accuracy of EWT and it may be more reliable than the studies suggest.
What is anxiety?
Anxiety is a state of emotional and physical arousal. The emotions include having worried thoughts and feelings of tension. Physical changes include an increased heart rate and sweating.
How is anxiety thought to potentially have a positive effect on accuracy of EWT recall?
The physiological arousal from anxiety triggers the fight or flight response which increases our alertness and improves our memory for the event because we become more aware of cues in the situation.
How is anxiety thought to potentially have a negative effect on accuracy of EWT recall?
It creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse.
Explain tunnel theory
Tunnel theory argues that a witness’ attention narrows to focus on a weapon because it is the source of the anxiety. This leads to the weapon-focus effect where this tunnel focus then negatively affects the recall of the overall event
Explain the Yerkes-Dodson law
This law states that performance (not only in memory recall, but in other processes such as sport and exams) improves with an increase in arousal up to some optimal point and then declines with further increases.
An increase in anxiety leads to an increase in physiological arousal. This therefore heightens alertness and may improve our memory because we become more aware of cues in the situation.
However if it gets too high, anxiety may cause you to lose focus and therefore negatively affect performance.
Describe the procedure, results and conclusion Johnson and Scott’s study of the effect of anxiety on recall
Participants in this study were left in a waiting area outside a laboratory whilst waiting for the “real” study to start. While they were waiting one of two situations occurred. In the first situation (low anxiety), they overheard a discussion in the laboratory about equipment failure, followed by a man leaving the laboratory holding a pen and with grease on his hands. In the second situation (high anxiety), participants overheard a heated discussion in the laboratory with the sound of breaking glass and crashing chairs, followed by a man leaving the laboratory carrying a paper knife covered in blood.
The participants were later asked to identify the man from a set of 50 photographs with the result that 49% correctly identified the man holding the pen, but only 33% could identify the man with the bloodstained knife.
Negative effect - it creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse.
Describe the procedure, results and conclusion of Christianson and Hubinette (1993) study which suggests that anxiety has a positive effect on recall
58 witnesses of 22 real life bank robberies in Sweden were interviewed some time after the robberies. Some of the witnesses had been onlookers or customers in the bank (low anxiety), and others were bank employees who had been directly threatened or subjected to violence during the robberies (high anxiety).
They found that all witnesses showed generally good memories for details of the robbery itself (better than 75% accurate recall). Those witnesses who were most anxious had the best recall of it.
Positive effect - the physiological arousal from anxiety triggers the fight or flight response which increases our alertness and improves our memory for the event because we become more aware of cues in the situation.
Pickel provided evidence that Johnson and Scott may not have been testing anxiety. What did they think they may have been testing and how did their study support this?
It has been suggested that the Johnson and Scott (1976) study is actually testing surprise rather than anxiety. The reason why participants may focus on the weapon may be because they are surprised at what they see rather than because they are scared. Pickel (1998) conducted an experiment using scissors, a handgun, a wallet or raw chicken as the handheld items in a hairdressing salon video. It would be assumed that the scissors would create low anxiety and low unusualness in this situation. They found that eyewitness accuracy was poorer in the high unusualness conditions – the raw chicken and the handgun.
This suggests that there may be an alternative explanation for the weapon-focus effect. This finding suggests that it may be unusualness, rather than threat, that captures our attention, and therefore affects memory for the rest of the event. Therefore, the study may not actually tell us anything about the effects of anxiety on EWT at all and so can’t be taken as strong support for the theory.
The studies investigating anxiety tend to either be laboratory experiments or natural experiments. Explain the strengths/weaknesses of using these to study anxiety.
Ignore
In field and natural experiments researchers usually interview real-life eyewitnesses sometime after the event. In this time all sorts of things could have happened that the researcher has absolutely no control over, such as accounts in the media, interviews by police, post event discussion etc. It is possible that these extraneous variables may be responsible for the accuracy of recall. The effects of anxiety may be overwhelmed by these factors, and impossible to test by the time the participants are interviewed. Therefore, the studies can’t provide particularly strong support for the effects of anxiety on EWT.
In most lab experiments, participants are shown a filmed (and usually staged) crime. Most of the participants will be aware that they are watching a filmed crime for a reason to do with the study. Chances are that most of them will work out for themselves that they are going to be asked questions about what they have seen. It is possible that these demand characteristics may be responsible for the accuracy of recall. Therefore, lab experiments may not provide strong support for the effects of anxiety on EWT as they may not yield internally valid results.
What is the cognitive interview?
A method of interviewing eyewitnesses to help them retrieve more accurate memories. It uses four main techniques, all based on evidence-based psychological knowledge of human memory - report everything, reinstate the context, reverse the order and change perspective.
Name and define the four techniques of the cognitive interview
Report everything - The witness is encouraged to include every single detail of the event, even if they seem irrelevant or trivial
Reinstate the context - The witness should return to the original crime scene in their mind and imagine the environment (e.g. weather, what they could see) and their emotions. Then they are asked to describe what they saw.
Reverse the order - Events should be recalled in a different chronological order to the original sequence e.g. from the final point back to the beginning or from the middle to the beginning.
Change perspective - Witnesses should recall the incident from the perspective of some else e.g. another witness or the perpetrator.
Give an example question that could be asked by the police using each technique of the cognitive interview
Report everything - Could you please recall every detail of the event even if you don’t think its relevant
Reinstate the context - Imagine you are back at the crime scene. Picture the environment, what was there, what it smelled like, how you felt at the time. Now please describe what you can recall about the event.
Reverse the order - Please describe what you can recall about the event from the end (INSERT WHAT HAPPENED AT THE END) backwards to the beginning (INSERT THE BEGINNING)
Change perspective - Please describe what you can recall from the perspective of the shop keeper
Explain why each technique is thought to be important
Report everything - Witnesses might not realise that some details are important, and these may trigger (act as cues for)other important memories.
Reinstate the context - Recalling how you felt and the environment could enhance recall (think context-dependent and state-dependent forgetting) i.e. By making the context/state at encoding and retrieval match, according to the encoding-specificity principle, the cues should be helpful at retrieval and lead to more accurate testimonies
Reverse the order - This is to prevent people from reporting their expectations of how the event must have happened rather than the actual events. It also prevents dishonesty as it’s harder to lie when you have to explain something backwards.
Change perspective - This disrupts the effect of expectations and schema on recall. The schema you have for a particular setting (e.g. going into a shop) generate expectations of what would have happened and it is the schema that is recalled rather than what actually happened.
Which two techniques have been found to be more effective at increasing recall? Why is this thought to be the case?
Some research has found that using a combination of report everything and reinstate the context produced better recall than any of the other conditions. This confirmed police officers’ suspicions that some aspects of the CI are more useful than others.
This supports that at least these two elements should be used to improve police interviewing of eyewitnesses even if the full CI isn’t used. [in here, you should add why they are likely to be effective using retrieval failure theory]. This in turn increases the credibility of the CI amongst those who use it – police officers.
What did Kohnken et al. Find about the enhanced cognitive interview?
Kohnken et al. combined data from 55 studies in a meta-analysis. The enhanced CI consistently provided more correct information than the standard interview used by police (81% increase in correct information). Kohnken et al. also found a 61% increase in the amount of incorrect information when the enhanced CI was used compared to the standard interview.
This is a strength because such studies indicate that there are real practical benefits to the police using the enhanced version of the CI. This research suggests that it gives the police a greater chance of catching and charging criminal, which is beneficial to society as a whole. However, the police should consider that the enhanced CI also increases the amount of incorrect information and so testimonies using is should still be treated with some caution.
Why are the police often reluctant to use the cognitive interview?
Police may be reluctant to use the CI because it takes much more time than the standard police interview. For example, more time is needed to establish a rapport with the witness and allow them to relax. The CI also requires special training and many forces have not been able to provide more than a few hours.
This means that it is unlikely that the ‘proper’ version of the CI is actually used, which may explain why more police have not been that impressed by it. Therefore, the CI may be effective when used correctly, but it is often not.
Why is it difficult to work out the overall effectiveness of the cognitive interview?
Studies of the effectiveness of the CI use slightly different variations of the CI and some use the enhanced CI. The same is true in real life – the police evolve their own methods.
This means that it is difficult to truly evaluate the effectiveness of the CI because a true comparison cannot be made. Therefore from the research, we can’t strongly support the use of the CI by the police.
