Psychology > Memory > Flashcards
Memory Flashcards
What is the STM?
A temporary memory store that holds a limited amount of information for a short period. The MSM views STM as a unitary store, whereas the WMM sees it as a number of components.
What is the LTM?
The LTM is a permanent store that holds unlimited amounts of information for long periods of time. There are 3 different types of LTM which are episodic, semantic, and procedural
How did Baddeley test coding in memory?
He gave 4 groups different lists of words to remember which were:
- acoustically similar
- acoustically dissimilar
- semantically similar
- semantically dissimilar
How is STM coded?
Acoustically
How is LTM coded?
Semantically
What’s the capacity of STM?
Jacobs found the mean span for digits was 9.3 and letters was 7.3
Miller suggested capacity was 7+-2
People use chunking in recall
Outline Peterson & Peterson’s study on duration of STM
Method:
- 24 students
- 8 trials
- each participant was given a consonant syllable and a 3 digit number (THX 512)
- asked to recall the consonant syllable after 3, 6, 9, 12,15 or 18 seconds
- during the retention interval they had to count backwards from their 3 digit number to prevent reversal
Results:
- 90% correct after 3 secs
- 20% correct after 9 secs
- 2% correct after 18 secs
Duration of STM
18 - 30 secs
Outline Bahrick’s study on the duration of LTM
- 392 participants from Ohio, aged 17 - 74
- Used high school yearbooks
- Recall was tested with:
-> photo recognition test consisting of 50 photos
-> free recall test where participants recalled all the names of their graduating class
In recall using a cue, such as photo recognition from yearbook photos:
- 90% accuracy after 15 years
- 70% accuracy after 48 years
Asked to list names of people participants went to school with:
- 60% after 15 years
- 30% after 48 years
Who created the MSM?
Atkinson and Shiffrin (1968)
What is the MSM?
A visual representation of memory. The STM and LTM are unitary stores. Information flows in a linear fashion through each store.
Sensory register -> STM -> LTM
Outline the sensory register
Separate sensory registers for each store
Iconic - coded visually
Echoic - coded acoustically
Very large capacity
Duration of milliseconds
Different coding for each store
Need to pay attention for it to be transferred to STM
Outline episodic memory
The ability to recall events from our lives, memory of personal experiences. These memories have 3 specific elements, including details of the event, the context, and emotions
Explicit memory
Associated with the hippocampus
Outline semantic memory
Memory of knowledge, facts, concepts, and meaning.
Explicit memory
Associated with the temporal lobe
Outline procedural memory
The memory of performed tasks / skills
Implicit memories
Associated with the cerebellum and motor cortex
What are implicit memories?
Knowing how
What are explicit memories?
Declarative, knowing that
Who came up with the WMM?
Baddely and Hitch
What does the WMM suggest?
The STM is made up of multiple stores and the MSM is to simple and doesn’t account for some research findings
Outline the central executive
Known as the ‘boss’ of the WMM
Directs attention to particular tasks and controls the 2 slave systems
Limited capacity
Outline the phonological loop
Processes and retains the order of heard information
Is divided into 2 sub-stores
Articulatory control process:
- inner voice, allows for maintenance rehearsal
Phonological store:
- inner ear, stores acoustic items for short periods
Outline the visuo-spatial sketchpad
Stores visual and spatial information
Plans spatial tasks
Divided into 2 substores
Inner scribe:
- spatial relationship
Visual cache:
- visual information
What is the role of the episodic buffer?
Binds and integrates information from all the other components and sends that information to the LTM
Outline the dual task performance study relating to the WMM
Baddeley et al showed that participants had more difficulty doing 2 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.
What are the explanations for forgetting?
Interference
Retrieval failure
What is proactive interference?
When an older memory interferes with a newer one. Pro, in this context, means working forwards, from old to new.
What is retroactive interference?
Where a newer memory interferes with an older one. Retro, in this context, means working backwards.
Outline McGeoch and McDonald’s study on interference
- Studied interference by changing the amount of similarity between 2 sets of materials
- Pt’s had to learn a list of 10 words until they could remember them with 100% accuracy
- They then learned a new list
- There were 6 groups of participants who had to learn different types of lists:
-> synonyms
-> antonyms (opposite meanings)
-> unrelated words
-> consonant syllables
-> 3-digit numbers
-> no new list
Findings:
- The synonyms group produced the worst recall of the first word list
- This shows that interference is strongest when the memories are similar
Outline research support for interference
Proactive interference - Underwood conducted a meta analysis and concluded that when participants have to learn a series of wordlists, they do not learn the lists encountered later on in the sequence as well as the ones at the start. Overall he said that if participants memorise 10 or more lists, then after 24 hours, they could only recall a very small amount, compared to when they only learned one list, they could recall much more.
Retroactive interference - Muller gave participants a list of nonsense syllables to learn for six minutes then after an interval they had to recall. If participants had been given an intervening task, they recalled much less.
Outline retrieval failure theory
The inability to recall something is because the cue needed to trigger the memory isn’t present.
Encoding specificity principle:
- Tulving discovered that for a cue to help us recall information it needs to be present at encoding and retrieval
- when participants were given a cue, which was the categories, they accurately recalled 60% of words compared to 40% of words remembered during free recall
Context dependent cues -> external, such as location
Mental / state dependent cues -> internal, such as being in the same emotional state when the memory is encoded and retrieved can be a trigger
Outline research support for the encoding specificity principle
A study was conducted where participants had to learn and 48 words belonging to 12 categories. Participants had to recall as many words as they could in one of two conditions, the first being where they were given a cue and the second being free recall. Average words recalled were 60% compared to 40% showing that having cues at the time of encoding can significantly help recall information
Outline Godden and Baddeley’s study on context-dependent forgetting
- Deep sea divers were asked to learn and recall a list of words under one of 4 conditions:
-> learn on land, recall on land
-> learn on land, recall underwater
-> learn underwater, recall on land
-> learn underwater, recall underwater
Findings:
- Accurate recall was 40% lower in the 2 conditions where learning and retrieval was in different contexts
- The external cues available at learning were different from the ones at recall, and this led to retrieval failure
Outline Carter and Cassaday’s study on state-dependent forgetting
- They gave antihistamine drugs with a mild sedative (drowsy) effect to their participants
- The participants had to learn lists of words and passages of prose and then recall the information
- There were 4 conditions:
-> learn on drug, recall on drug
-> learn on it, recall off it
-> learn off it, recall on it
-> learn off it, recall off it
Findings:
- In conditions where there was a mismatch between internal state at learning and recall, performance on the memory test was significantly worse
- When cues are absent, there is more forgetting
Outline research support for state-dependent forgetting
The mental state you are in at the time of learning information can also act as a cue. Goodwin conducted a study, where he asked male volunteers to learn a list of words while they were either drunk or sober. The participants then were asked to recall the words 24 hours later, where some were sober, but others had to get drunk again. The recall scores were much higher when they were in the same state as when they learnt the information.
What is the accuracy of eyewitness testimony affected by?
Misleading information
-> leading questions
-> post-event discussion
Anxiety
Age
What is misleading information?
Misleading information is a key factor that can affect the accuracy of eyewitness testimony. Misleading information is incorrect information given to an eyewitness following an event. This can be during post - event discussion of take the form of leading questions.
Outline misleading information as a factor affecting eyewitness testimony
Leading questions:
Response bias explanation -> the wording of the question has no effect on the participants memories, but influences now they answer
Substitution explanation -> the wording of a leading question changes the participants memory
Post - event discussion:
- Eyewitness testimonies may become contaminated when they discuss the crime with other witnesses
- They combine (mis)information from other witnesses with their own memories
- The memory of an event may be incorrect or altered after discussing it with others or being questioned about it multiple times
Outline Loftus and Palmer’s research on the effect of leading questions on eyewitness testimony
45 participants were shown seven films of different traffic accidents. Each participant was then given a questionnaire with a list of questions about the crash, with one critical question ‘how fast were the cars going when they (verb) each other?’ The verb was replaced with either smashed, collided, bumped, hit, or contacted. This was a leading question based on the verb used. The results showed an average of 10 mph mean difference between contacted and smashed. Another experiment was done but this time only two verbs were used; smashed and hit and a control group. One week later they were asked whether they had seen any glass and found that while most said no, more people in the smashed condition did say yes.
Outline Gabbert’s study on post-event discussion
- Gabbert studied participants in pairs
- Each participant watched a video of the same crime, but filmed from different points of view
- Both participants discussed what they had seen before individually completing a test of recall
Findings:
- 71% of participants mistakenly recalled aspects of the event they did not see in the video, but had picked up in the discussion
- The corresponding figure in a control group, where there was no discussion, was 0%
- Gabbert et al concluded that witnesses often go along with each other, either to win social approval or because they believe other witnesses are right and they are wrong
- This phenomenon is called memory conformity
Anxiety - weapon focus effect
Weapon focus effect:
- where a witness focuses their attention on the weapon being used in a crime
- this causes a state of anxiety which leads to difficulties in recalling details accurately
Negative effect on recall:
- the tunnel theory of memory argues that a witness’s attention narrows to focus on a weapon because its a source of anxiety
- anxiety creates physiological arousal in the body which prevents us from paying attention to important cues, so recall is worse
Positive effect on recall:
- the stress of witnessing a crime or accident creates anxiety through physiological arousal within the body
- the fight or flight response is triggered, which increases our alertness and improves our memory of the event because we become more aware of cues in the situation
Outline Johnson and Scott’s research on the effect of anxiety on recall (negative effect)
- participants believed they were going to take part in a lab study
- while seated in a waiting room, they heard an argument in the next room
- in the ‘low anxiety’ condition, a man walked through the waiting area carrying a pen with grease on his hands
- in the ‘high anxiety’ condition, they heard the argument followed by the sound of breaking glass, and a man walked out of the room holding a paper knife covered in blood
- the participants later had to pick out the man from a set of 50 photos
Findings:
- 49% of participants who had seen the man with the pen could identify him
- 33% could in the knife condition
- The tunnel theory of memory argues that a witness’s attention narrows to focus on a weapon, because its a source of anxiety
Outline Yuille and Cutshall’s research on the effect of anxiety on recall (positive effect)
- conducted a study of a real-life shooting in a gun shop in Canada, where the shop owner shot a thief dead
- there were 21 witnesses, and 13 agreed to take part
- the interviews were held 4-5 months after the incident, and were compared with the original police interviews made at the time of the shooting
- accuracy was determined by the number of details reported in each account
- the witnesses were asked to rate how stressed they had felt at the time of the incident, and asked if they had had any emotional problems since the event
Findings:
- the witnesses were very accurate in their accounts, and there was little change in the amount of accuracy after 5 months
- participants who reported the highest levels of stress were most accurate, at about 88% compared to 75%
What is the Yerkes-Dodson law?
Lower levels of anxiety produce lower levels of recall accuracy. Memory becomes more accurate as the level of anxiety experienced increases. However, there comes a point where the optimal level of anxiety is reached, and this is the point of maximum accuracy. If an eyewitness experiences any more stress than this, their recall of the event suffers a drastic decline.
Who developed the cognitive interview?
Geiselman et al (1985)
What are the 4 techniques used in a cognitive interview?
- Recall / report everything
- smaller seemingly unimportant details may trigger a bigger memory / help piece smaller things together - Context reinstatement
- mentally recreate both the physical and physiological environment, allow for emotional and contextual cues - Reverse / change order
- different timelines, not in chronological order to remove schemas - Change perspective
- look at it from a different point of view, to remove schemas
What is the enhanced cognitive interview (ECI)?
Fisher et al (1987)
- additional elements were developed that focus on the social dynamics of the interaction
- interviewer needs to know when to establish eye contact and when to relinquish it
- enhanced CI includes ideas such as reducing eyewitness anxiety, minimising distractions, getting the witness to speak slowly, and asking open ended questions
What are the limitations of a standard interview?
Close ended questions
Don’t maximise recall
Short answers
Brief questions to elicit facts
Witness concentration broken by interruptions
Evaluate research into the coding of memory
One limitation of Baddeley’s study was that it used artificial stimuli rather than meaningful material. The word lists had no personal meaning to participants. This means we should be cautious about the generalising findings to different kinds of memory task. For example, when processing more meaningful information, people may use semantic coding even for STM tasks. This suggests that the findings from the study have limited application.
One limitation of Baddeley’s study is that is may not have tested LTM. Baddeley’s methodology has been criticised, since in the study Baddeley tested STM by asking participants to recall word list immediately after hearing it, but LTM was tested by waiting 20 minutes. It is questionable as to whether this is really testing LTM. This casts doubt on the validity of Baddeley’s research because he may have not been testing the LTM after all.
Evaluate research into the capacity of memory
One limitation of Jacob’s study is it 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 were not controlled. However, the results of this study have been confirmed in other studies such as Miller’s, supporting its validity. Therefore, the validity of Jacob’s study may be called into question.
One limitation of Miller’s research is that he may have overestimated the capacity of STM. Cowan reviewed a variety of studies on the capacity of STM and concluded that the STM is likely to be limited to 4 chunks, meaning that the lower end of Millers estimate (5 chunks) is more appropriate than 7. This suggests that the STM is not as extensive as we thought.
Evaluate research into the duration of memory
A limitation of the Petersons’ study is it may not have measured what it was meant to measure, meaning it may lack internal validity. In the study, participants were counting numbers to prevent reversal, but this may have led to displacement of the consonant syllables. Reitman used auditory tones instead of numbers so that displacement wouldn’t occur and found that the duration of STM was longer. This suggests that forgetting in the Peterson’s study was due to displacement rather than decay, and suggests the study had low internal validity.
One strength of Bahrick et al’s study is it has high external validity; real life, meaningful memories were studied. When studies on LTM have been conducted with meaningless pictures to be remembered, recall rates were lower. However, confounding variables could not all be controlled, such as the fact that Bahrick’s participants may have looked at their yearbook photos and rehearsed their memory over the years.
Evaluate the MSM
One strength of the MSM comes from the case of Clive Wearing. Clive nearing suffered brain damage from encephalitis which resulted in severe amnesia, and he was unable to transfer information from his STM to LTM. This is significant as is demonstrates that the MSM is sequential, and that if the ability to ‘transfer’ information from the STM to the LTM is broken, we cannot form new memories, thus supporting the linear nature of the model.
A limitation of the multi store model comes from patient KF. Patient KF was injured in an accident, and following this KF could recall information stored in his long-term memory, but had issues with his short-term memory. He could remember visual images, but not acoustic information. The multi store model states there is one short-term memory, however research into patients such as KF with amnesia suggests there could be another short-term store for non-verbal sounds. This is a limitation because research shows there must be at least two short-term memory stores; one for visual information and one for auditory.
A strength of the multi store model is it has supporting evidence. Controlled lab studies on capacity, duration, and coding of memory support the existence of a separate short and long-term memory store, which is the basis of the multi store model. Studies using brain scanning techniques have also demonstrated that there is a difference between short-term memory and long-term memory. For example, Beardsley found that the prefrontal cortex is active during short-term memory, but not long-term memory tasks. This evidence provides strong support for the multi store model.
A strength of the multi store model is psychologists have shown there are different areas of the brain involved in short-term memory and long-term memory from the case study of patient HM. HM had brain damage from an operation that remove the hippocampus from both sides of his brain to reduce his severe epilepsy. HM‘s personality and intellect remained intact, but he couldn’t form new long-term memories. This provides support for the multi store models notion of separate stores, as HM was unable to transfer information from his short-term memory to his long-term memory, but was able to retrieve information from before his surgery from his long-term memory. This also supports the fact that the multi store model is sequential.
One strength of the multi store model is support from studies showing that the short-term memory and long-term memory are different. For example, Baddeley found that we tend to mix up words that sound similar when we are using a short-term memory, but we mix up words that have similar meanings when we use our long-term memory. Further support comes from studies of capacity and duration. These studies clearly show that short-term memory and long-term memory are separate and independent memory stores, as claimed by the multi store model. However, all these studies used artificial tasks and stimuli to research memory, and thus the findings from this research may not apply to our everyday lives, where we have to remember much more meaningful information. This suggests that the multi store model may not be a valid model of memory.
Evaluate different types of LTM
Research support for the existence of different types of long-term memory comes from the case study of patient HM. Patient HM had his hippocampus removed in an attempt to reduce the quantity and severity of his seizures. He was able to talk normally and recall everything from before his surgery, but he was unable to retain any new information. Patient HM supports the existence of different types of long-term memory, as although he couldn’t form new memories, he could still perform procedural tasks such as riding a bike. This suggests that while his episodic memory was damaged, his procedural memory was fine, highlighting a clear distinction between different types of long-term memory.
Brain scans provide support for the distinction of different types of long-term memory. Research has shown that different parts of the brain are active when accessing episodic, semantic and procedural memory. Episodic memory is associated with the hippocampus and temporal lobe; semantic memory is associated with the temporal lobe, and procedural memory is associated with the cerebellum and motor cortex. This research suggests that the different brain regions are responsible for the different types of long-term memory, supporting the idea that our long-term memory is made up of at least three distinct categories.
A strength of research into the different types of long-term memory is that understanding types of long-term memory allows psychologists to help people with memory problems. For example, as people age, they experience memory loss. Research is shown that this seems to be specific to episodic memory, as it becomes harder to recall memories of personal events/experiences that occurred relatively recently, though past episodic memories remain intact. Belleville et al devised an intervention to improve episodic memories in older people. The trained participants performed better on a test of episodic memory after training than a control group. This shows that distinguishing between types of long-term memory enables specific treatments to be developed.
A limitation of studies on types of long-term memory is it is difficult to reach a firm conclusion by studying brain damaged patients. There are many problems with evidence from brain damage patients such as it is difficult to generalise to the whole population, and in addition, the difficulty with the studies of amnesiacs, including HM is that it is difficult to be certain of the exact parts of the brain that have been affected until the patient has died. Most studies are conducted with living patients. Damage to a particular area of the brain does not necessarily mean that that area is responsible for particular behaviour - it may be acting as a relay station. Malfunction of the relay station would impair performance. This means we cannot establish a causal relationship between a particular brain region and a type of long-term memory.
Although patient HM and PM provide support for the distinction of separate types of long-term memory, evidence from case studies must be treated with caution. It is difficult to establish exactly which brain regions are affected in patients with brain damage and damage to a particular region doesn’t necessarily mean that region is associated with a particular type of memory.
Evaluate the working memory model
A limitation of the working memory memory model is some psychologists feel the concept of the central executive is too vague and doesn’t really explain anything. Although the central executive is the most important component, there has been little research investigating this component. It isn’t clear exactly how the central executive works or what it does, and this vagueness means it can’t be used to explain an experimental results. Critics also feel that the notion of a single central executive is wrong and there are probably several components in a case. Study of patient EVR, who had a cerebral tumour removed, showed he performed well on tests requiring reasoning, which suggests the central executive was intact. However, he had poor decision-making skills which suggests that, in fact, the central executive was not wholly intact. In summary, the account offered of the central executive is unsatisfactory, because it is probably more complex than Baddeley and Hitch originally suggested.
A strength of the working memory model is it is supported by case studies, such as patient KF. KF suffered from brain damage after motorcycle accident, but his short-term forgetting of auditory information was much greater than that of visual stimuli. In addition, his auditory problems were limited to verbal material such as letters and digits, but not meaningful sounds. Thus, his brain damage seem to be restricted to the phonological loop. This supports the idea of separate visual and spatial systems, as suggested by the working memory model. However, it is unclear whether KF had other cognitive impairments which might have affected his performance on memory tasks. For example, his injury was caused by a motorcycle accident, and the trauma involved may have affected his cognitive performance. This challenges evidence that comes from clinical studies of people with brain injuries that may have affected many different systems.
A strength of the working memory model lies in the phonological loop and its explanation of the word length effect, which is the fact that people cope better with short words than long words in working memory. It seems that the phonological loop holds the amount of information that you can say in two seconds. This makes it hard to remember a list of long words such as ‘association’ and ‘representative’ compared to short words like ‘harm’ and ‘twice’. The longer words can’t be rehearsed on the phonological loop because they don’t fit. However, the word-length effect disappears if a person is given an articulatory suppression task. For example, if you’re asked to say ‘the, the, the…’ while reading the words. This repetitive task ties up the articulatory process and means you can’t to rehearse the shorter words more quickly than a longer words, so the word length effect disappears. This is evidence for the articulatory process, which is a key component of the working memory model.
A strength of the working memory model is that studies of dual task performance support the separate existence of the visuo-spatial sketchpad. When Baddeley et al’s participants carried out a visual and verbal task at the same time, their performance on each was similar to when they carried out the tasks separately. However, when both tasks were visual or verbal, performance on both declined substantially. This is because both visual tasks and both verbal tasks complete for the same sub-system, whereas there is no competition when performing a verbal and visual task together. This shows there must be a separate sub-system that processes visual input.
Evaluate interference as an explanation for forgetting
One limitation is that interference is temporary and can be overcome by using queues. Tulving and Psotka gave participants lists of words organised into categories, one at a time. Recall averaged about 70% for the first list, but became progressively worse as participants learned each additional list, demonstrating proactive interference. At the end of the procedure, the participants were given a cued recall test - they were told the name of the categories. Recall rose again to about 70%. This shows that interference causes a temporary loss of accessibility to material that is still in the long-term memory, a finding not predicted by interference theory.
A limitation of interference as an explanation of forgetting is there is evidence that some people are less affected by proactive interference and others. Kane and Engle demonstrated that individuals with a greater working memory span were less susceptible to proactive interference. The researchers tested this by giving participants three word lists to learn. Those participants with low working memory spans showed greater proactive interference when recalling the second and third lists than did participants with higher spans. A further test suggested that having a greater working memory span meant having greater resources to consciously control processing and counteract the effects of proactive interference. This highlights the role that individual differences play in how people are affected by interference.
One strength is that there is evidence of interference effects in more everyday situations. Baddeley and Hitch asked rugby players to record the names of the teams they had played against during the season. The players all played for the same time interval over one season, but the number of intervening games varied because some players missed matches due to injury. Players who played the most games had the poorest recall. This study shows that interference can operate in at least some real-world situations, increasing the validity of the theory. However, while interference may cause some forgetting in everyday situations, it is unusual. This is because the conditions necessary for interference to occur are relatively rare. This is unlike lab studies, where the high degree of control means a researcher can create ideal conditions for interference. For example, 2 memories have to be fairly similar in order to interfere with each other. This may happen occasionally in everyday life, but not often. This suggests that most forgetting may be better explained by other theories, such as retrieval failure due to a lack of cues.
Evaluate retrieval failure as an explanation for forgetting
A limitation of retrieval failure is that the relationship between encoding cues and later retrieval is a correlation rather than a cause. Naime (2002), called out the myth of the encoding - retrieval match, and Baddeley made a similar criticism. He pointed out that the encoding specificity principle is impossible to test, because it’s circular. If a stimulus leads to the retrieval of a memory, then it must’ve been coded, but if it doesn’t lead to the retrieval of a memory, then, according to the encoding specificity principle, it can’t have been encoded in memory. However, it is impossible to test for an item that hasn’t been encoded in memory, so this can’t be proved. Therefore the cues may not cause retrieval but just be associated with retrieval.
A strength of retrieval failure as an explanation of forgetting as it has real world application. An obvious application of this research is to use it to improve recall when needed such as when taking your exams. Abernethy’s research suggests you should revise in the room you take your exam. Smith showed that even just thinking of the room where you did the original learning (mental reinstatement) was as effective as actually being in the same room at the time of retrieval. Another application of retrieval cues is in the cognitive interview. This shows how research into retrieval failure can suggest strategies for improving recall in real-world situations, such as taking exams or giving eyewitness testimony.
A limitation of retrieval failure as an explanation for forgetting is the context effect may be related to the kind of memory being tested. Godden and Baddeley replicated the 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 retrieving it for themselves. When recognition was tested, there was no context dependent effect; performance was the same in all four conditions. Therefore, this is a limitation of context effects, because it means that the presence or absence of cues only affects memory when you test it in a certain way.
A strength of the retrieval failure explanation is its ability to explain interference effects. Psychologists demonstrated that apparent interference effects are actually due to the absence of cues. Participants were given six different word lists to learn, each consisting of 24 words, divided into six different categories. Participants were then asked to list the words with no cues, or after being given the category names as cues. The more lists a participant had to learn, the worse their performance became, which is evidence of retroactive interference. However, when participants were given cued recall the effects of interference disappeared; they remembered about 70% of the words, regardless of how many lists they have been given. This shows that the information is there, but cannot be retrieved, and therefore retrieval failure is a more important explanation of forgetting than interference.
Evaluate Loftus and Palmer’s research on misleading information as a factor affecting eyewitness testimony
One issue with Loftus and Palmer‘s research is that it lacks population validity. Loftus and Palmer’s sample consisted of 45 American students. This matters, because it means this research may not be generalisable to the general population and maybe culturally biased. We don’t know if other cultures would also be susceptible to the effects of misleading information, and we are unable to conclude whether misleading information affects the accuracy of eyewitness testimony in other countries.
Another issue with Loftus and Palmer‘s research is that they deceived their participants, and therefore did not adhere to the code of ethics. Loftus and Palmer didn’t tell their participants the true aim of their research, and therefore didn’t abide by the BPS code of ethics. However, it could be argued that deception was necessary in order to obtain valid results. If Loftus and Palmer had told the participants they were going to be misled, this would’ve led to demand characteristics where the participants changed their behaviour, therefore affecting the results of the study. Therefore, as it was unlikely that any of the participants were harmed from the study and all the participants were debriefed, the deception in this study was a strength to ensure the collection of valid data to further our understanding into the effects of misleading information on the accuracy of eyewitness testimony.
Another criticism of Loftus and Palmer‘s research into eyewitness testimony is the possibility of a response bias. Loftus and Palmer found that leading questions changed the original memory. However, Bekerian and Bowers replicated a study by Loftus et al, and found that participants are not susceptible to misleading information if questions are presented in the same order as the original data . This suggests that the order of questions had a significant effect, and therefore memory change was due to response bias, not storage. This provides an alternative explanation to Loftus and Palmer and highlights the importance of question order in police interviews.
Evaluate misleading information as a factor affecting eyewitness testimony
Loftus’ research suggested that eyewitness testimony was generally inaccurate and therefore unreliable. However, not all researchers agree with conclusions derived from laboratory experiments. Foster et al found that if participants thought they were watching a real life robbery, and also thought that their responses would influence the trial, then the identification of the robber was more accurate. Furthermore, Yuille and Cutshall found 13 witnesses of an actual armed robbery in Canada gave accurate details of the event when interviewed four months later. Their interview statements were compared to the detailed reports they gave at the time of witnessing the robbery. From these studies, it seems research conducted with participants who have experienced real life crimes do provide accurate eyewitness testimony. This may be because the importance placed on the events they are witnessing strengthens the memory for the event and so the memory is more resistant to misleading information. This research also suggests that we should treat the findings of lab studies of eyewitness testimony with caution.
One strength of research into misleading information is that it has important practical uses in the criminal justice system. The consequences of inaccurate EWT can be very serious. 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. Psychologists are sometimes asked to act as expert witnesses in court trials and explain the limits of EWT to juries. This shows that psychologists can help to improve the way the legal system works, especially by protecting innocent people from false convictions based on unreliable EWT. However, the practical applications of EWT may be affected by issues with research. For instance, Loftus and Palmer’s participants watched film clips in a lab, a very different experience from witnessing a real event. Also, Foster et al point out that what eyewitnesses remember has important consequences in the real world, but participants’ responses in research don’t matter in the same way. This suggests that researchers such as Loftus are too pessimistic about the effects of misleading information, as EWT may be more dependable than may studies suggest.
One limitation of the substitution explanation is that EWT is more accurate for some aspects of an event than for others. For example, Sutherland and Hayne showed participants a video clip. When participants were later asked misleading questions, their recall was more accurate for central details of the event than for peripheral ones. Presumably, the participants’ attention was focused on central features of the event, and these memories were relatively resistant to misleading information. This suggests that the original memories for central details survived and were not distorted, an outcome that is not predicted by the substitution explanation.
A criticism of research investigating eyewitness testimony concerns individual differences of witnesses. An eyewitness typically acquires information from two sources; from observing the event itself, and from subsequent suggestions. A number of studies are found that compared to younger subjects, elderly people have difficulty remembering the source of their information, even though their memory for the information itself is unimpaired. As a result, they become more prone to the effect of misleading information when giving testimony. This suggests that individual differences, age in particular, are an important factor when assessing the reliability of eyewitness testimony.
Evaluate Johnson and Scott’s research on anxiety as a factor affecting eyewitness testimony
One issue with Johnson and Scots study is that they deceived their participants. The participants were led to believe that they were sitting in the waiting room, waiting for the experiment to begin when in fact that was part of the real experiment. However, it was necessary for Johnson and Scott to deceive the participants in order to reduce demand characteristics and obtain valid results. Furthermore, Johnson and Scott would have debriefed their participants after the experiment, therefore justifying their use of deception. This matters because some of the participants may have not agreed to take part in an experiment, especially if they were aware that they may have been exposed to a knife, as this could cause high levels of stress and anxiety. However, as outlined above, the deception was necessary and the participants were unlikely to have experienced extreme anxiety as they were not not put in any real harm or danger.
One issue with Johnson and Scott’s research is that the experiment was carried out in a laboratory. Although the participants were in a waiting room, the participants knew that they were taking part in an experiment and this may have led to demand characteristics, where they might have suspected that something could happen at any moment. This matters because the demand characteristics could have affected the validity of the findings, and we cannot be certain that the findings were caused by anxiety as the participants may have been more anxious or expectant than usual.
Evaluate anxiety as a factor affecting eyewitness testimony
A criticism of the weapon focus effect comes from Pickel, who proposed that the reduced accuracy of identification could be due to surprise rather than anxiety. To test this she arranged for participants to watch a thief enter a hairdressing salon carrying scissors (high threat, low surprise), handgun (high threat, high surprise), wallet (low threat, low surprise) or a whole raw chicken (low threat, high surprise). Identification was least accurate in the high surprise conditions rather than high threat. This supports the view that the weapon focus effect is related to surprise rather than anxiety.
One issue with Johnson and Scott’s research and the claim that anxiety decreases the accuracy of eyewitness testimony is that not all studies support their findings. Yuille and Cutshall interviewed 13 witnesses 4 to 5 months after they saw a shooting where one person was killed. They found the witnesses were very accurate in their accounts, and there was little change in the amount or accuracy of recall. They also resisted leading questions, and their stress levels at the time of the event had little effect on their subsequent memory. This matters because it refutes Johnson in Scott’s research. They concluded that anxiety decreases the effectiveness of eyewitness testimony, but in a real life situation, Yuille and Cutshall found anxiety had little to no effect on eyewitness testimony. This matters because it casts doubts about the validity of lab studies on the accuracy of eyewitness testimony.
It has been suggested that one key extraneous variable variable in many studies of anxiety is emotional sensitivity. In a study by Bothwell et al, participants were tested for personality characteristics, and were labelled as either neurotic or stable. It was found at the stable participants showed rising levels of accuracy as stress was increased, whereas the opposite was true for neurotics; their accuracy levels decreased as stress increased. A psychologist pointed out that the modest effect sizes as shown in many studies of anxiety may be the result of averaging out low accuracy and high accuracy scores of sensitive and non sensitive participants respectively. These studies suggest that individual differences may indeed play an important role in the accuracy of eyewitness testimony.
Evaluate the cognitive interview
A limitation of the cognitive interview is that it takes longer to complete in the traditional interview technique. Kebell and Wagstaff found many police officers did not use the cognitive interview technique in less serious crimes as they did not have the time to carry out this type of interview. Police often use strategies to deliberately limit an eyewitness reports to the minimum amount of information deemed necessary by the officer. Therefore while cognitive interviews may produce a vast amount of information, it may not always be practical or helpful in terms of allowing the police to efficiently investigate incidents, especially then they’re seen as less serious.
A strength of the cognitive interview is the amount of supporting research. A meta analysis of 53 studies found on average an increase of 34% in the amount of correct information generated by the cognitive interview compared with standard interviewing techniques, although most of the studies involve volunteer witnesses, tested in a lab. However, the effectiveness of the cognitive interview may be due more to some individual elements, rather than the whole thing. Milne and Bull found that when participants were interviewed using a combination of the ‘report everything’ and ‘mental reinstatement’ components of the cognitive interview, their recall was significantly higher than when using just one individual component or the control condition. This suggests that overall the cognitive interview is an infective technique for increasing the accessibility of stored information.
A limitation of the cognitive interview is it creates an increase in inaccurate information. The techniques of the cognitive interview aim to increase the amount of correct information remembered, but the recall of incorrect information may also be increased. Köhnken et al found an 81% increase of correct information, but also a 61% increase of incorrect information when the enhanced cognitive interview was used compared to a standard interview. This matters, because if the cognitive interview cannot be reliably used it limits the application of it, especially within the criminal justice system. This means the cognitive interview has very limited application and it may not be worth the time it takes to train the officers and to actually do the cognitive interview compared to a standard interview.
