Memory (w/ Forgetting & Eyewitness Testimonies) Flashcards
What is Cognitive Psychology?
It’s about how our mind deals with information, and our abilities to use that information.
What is Memory?
The process of storing and retrieving information
What are the three types of memory storage commonly studied by cognitive psychologists?
- Coding - the type or format of information being stored
- Capacity - amount/ quantity of information that can be stored
- Duration - the length of time information is held for
What are the three memory storages are?
sensory memory/ sensory register, short- term memory, long term memory
What does the memory storages gives us?
This gives us an accurate account of the environment as experienced by the sensory system. We retain a literal copy of the stimulus long enough for us to decide whether it is worthy of further processing. Any information we do not pay attention to is lost by decay and does not go to short term memory.
What is the Coding of Sensory Memory?
Modality Specific (information is held in the same sense that it is registered- sight, hearing, touch, smell and taste). More research however is concentrated on iconic memory where visual images are kept for a short period. Echoic memory where auditory senses are kept for a short period and store in sensory memory which retains physical senses of touch and internal muscle tensions.
What is the Capacity of Sensory Memory?
large, high capacity
What is the Duration of Sensory Memory?
0.25 - 2 seconds
What is Sperling’s research?
- used a Tachistoscope - presented a 12 symbol grid for 1/20th of a second on a screen
- participants could recall 4 symbols but reported seeing a lot more than they had time to report
- demonstrates that the capacity of sensory memory is large
What is the evaluation of Sperling’s research?
Although evidence suggests that the capacity of sensory memory is very large, it isn’t well studied, as they last so briefly and generally at a pre-conscious level.
How is information passed from our sensory memory to our short term memory?
If we only possessed sensory memory we would retain very limited information. If we pay attention to information in sensory memory it is passed onto STM.
What is the Coding of Short-Term Memory?
acoustic
What is Conrad’s study?
- visually presented students with letters one at a time to study encoding in STM
- found that: letters which are acoustically similar (rhyming) are harder to recall from STM than those which are acoustically dissimilar (non-rhyming)
What is the Capacity of Short- Term Memory?
7 + or - 2 items (5 - 9 items)
Who stated that the capacity of STM is 5 - 9 items?
Miller (1956)
What did Miller think about the capacity of STM?
He felt that that the capacity of STM could be expanded if we chunked items together to reduce the number of separate items overall. e.g. if we combine letter onto words, words into phrases, phrases into sentences or even numbers into dates etc and then we can remember more information since each word of phrase or date would be one chunk of information.
What is the evaluation of Miller’s research?
Might have overestimated the capacity of STM. Cowan reviewed other research and found that capacity of STM was only around four chunks.
What is Jacobs’ study (1887)?
- developed a technique to measure digit span
- showed p’s 4 digits
- asked to recall them in the correct order
- if correct, repeat with 5 digits and carry on till they can’t recall in correct order
- mean span for digits (numbers) is 9.3 and 7.3 for letters
- concluded that STM is 5 - 9 items
What do you keep in mind when choosing letters or digits when testing capacity?
don’t use repetition, similar sounding, numbers shouldn’t form date, no acronym
What is the Duration of Short-Term Memory?
15 - 30s if not verbally rehearsed in the rehearsal loop to maintain it (maintenance rehearsal)
Who wanted to investigate the duration of short term memory?
Peterson and Peterson (1959)
What is the aim of Peterson and Peterson study?
examine duration of short term memory
What is the method of Peterson and Peterson study?
24 psychology students were shown 3 random letters (triagrom)
What is the results of Peterson and Peterson study?
After 3 seconds, 80% of 3 random letters were recalled correctly.
After 18 seconds, fewer than 3 than 10% of the random letters were recalled correctly
What is the conclusion of Peterson and Peterson study?
recall got progressively worse as delay grew longer. short term memory has limited duration to 15 - 30secs (average is 18s) if rehearsal is prevented
What is a Weakness of the Peterson and Peterson study?
A limitation of Peterson and Peterson’s research is that the stimulus material is artificial. They gave participants consonant syllable to memorise in a controlled artificial environment. This activity does not reflect real life activity where what we are trying to remember is meaningful. So we can say that the findings of this study lack external validity.
What is another of the Peterson and Peterson study?
Peterson and Peterson’s study supports the explanation that the memory trace disappears after a short duration if it is not rehearsed. However there could be an alternative explanation which states that information in STM is displaced because STM has a limited capacity and any new information pushes out what is currently in STM. In Peterson and Peterson’s study the participant’s counted backwards in 3’s before recalling the trigram. This could have led to the information in STM being displaced . This means that this study lacks Mternal
validity.
What is the Coding of Long-Term Memory?
semantic
What is Baddeley’s study?
- presented list of 10 short words, one at a time
- some lists were semantically similar, others weren’t
- tested immediately and after 20 min delay
- found that after 20 mins, they did poorly on the semantically similar words
What is a Weakness of Baddeley’s study?
He used artificial stimulus such as word lists rather than meaningful material. This means we should be cautious about generalising the findings to different kinds of memory task such as processing more meaningful information people may use semantic coding even for STM tasks. This suggests that the findings may have
limited application.
Who shown that Baddeley’s theory may not also be true?
Frost has also shown this may not always be true. The coding may also be visual or acoustic depending on the circumstances
What is the Duration of the Long- Term Memory?
anything up to a lifetime
Who investigated the duration of LTM using a natural experiment?
Bahrick et al (1975)
What is the aim of Bahrick et al (1975) study?
investigate duration of LTM
What is the method of Bahrick et al (1975) study?
392 American university graduates p’s aged between 17 - 74 given a recognition test. They were shown photographs from their high school year book
What is the results of Bahrick et al (1975) study?
70% of p’s tested 48 years after graduation were able to recognise the people in the photos
What is the conclusion of Bahrick et al (1975) study?
LTM can last lifetime or at least 48 years
What is a weakness of Bahrick et al (1975) study?
Real meaningful memories were studied. So this research has high ecological validity. The weakness however is that confounding variables are not controlled. E.g The participants may have looked at their yearbook and rehearsed the memory over the years impacting the validity of the findings.
What is the Capacity of the Long- Term Memory?
potentially unlimited. It is a vast storehouse of information, skills, abilities which aren’t currently being used but which are potentially retrievable.
What is Atkinson & Shiffrin’s (1968) multi-store model of memory?
environmental input -> sensory register (SR) -> attention -> STM -> prolonged rehearsal <- retrieval -> LTM
Sensory Register
Capacity: very large
Duration: limited
Coding: sense specific (echoic, haptic, iconic, acoustic)
How can information be lost in Sensory Register?
Information not paid attention to, is lost through decay
Short- Term Memory
Capacity: limited -> 5-9 chunks
Duration: very limited (18s - 30s)
Coding: acoustic
How can information be lost in Short- Term Memory?
If information isn’t rehearsed it’s lost in displacement since STM has limited capacity
Long- Term Memory
Capacity: unlimited
Duration: lifetime/ 48 years
Coding: semantic
How can information be lost in Long- Term Memory?
Information n[ot rehearsed is lost due to decay
What are Strengths of Atkinson & Shiffrin’s (1968) study?
- Most of the studies done on memory were laboratory experiments. They are carried out in controlled conditions and therefore help establish cause and effect between the variables being studied. They also due to the controlled environment have high levels of replicability. This is a strength since it helps provide scientific supporting evidence for the MSM.
- Clinical studies of amnesiacs show that it is possible for the long term memory to be damaged but the STM to be intact, suggesting that the two stores must function separately. → Supporting the MSM
What are Weaknesses of Atkinson & Shiffrin’s (1968) study?
It’s over simplified it assumes that there is a single STM and LTM.
In truth both these stores are much more complex than was originally thought.
- Long term Memory - we tend to remember how to ride a bicycle more easily even after not using that skill for a long time than rules for subtraction or calculating percentages. These are more than one type of LTM - procedural, episodic and semantic.
• Short term memory: The working memory model casts doubt on the
assumption that the STM is a single, unitary, passive store. It states that the STM is a multi- component, active store. Research with a patient with amnesia supports this idea by showing that there is a separate STM for visual information and a separate component for auditory information. This implies that the MSM is over- simplified.
What are more Weaknesses of Atkinson & Shiffrin’s (1968) study?
- Over emphasises rehearsal: This model proposes that the transfer
of information from STM to LTM is through rehearsal. It stresses on maintenance rehearsal (amount of it that you do). However this has been
Criticised by Craik and Watkins who have argued that what really matters is the type of rehearsal. They believe that the maintenance rehearsal stressed on by the MSM only maintains the information in STM but does not transfer it to LTM. On the other hand the type of rehearsal that is required to transfer information to LTM is elaborative rehearsal- when you think about what the information means and link it to existing knowledge. This is a limitation because it is a finding that cannot be explained by the MSM. - Research into the MSM has used artificial meaningless stimuli like letters, digits, sometimes simple stimuli like words. In everyday life we form memories related to all sort of useful things such as peoples’s faces, their names, facts, places. The findings of such research therefore do not reflect real life memories and therefore may not provide good support for the MSM.
What is Evidence of the Multi- Store Model?
There are several cases of patients who have suffered brain damage to their hippocampus & have memory deficits: like H.M. and Clive Wearing.
Clive Wearing suffered brain damage from a viral infection. He suffered almost complete amnesia - he forgets everything within 30 seconds. He only has semantic memory of his wife Deborah and he has intact procedural memory and can still play the piano.
What were the 3 types of LTM did Tulving suggest?
- semantic memory
- episodic memory
- procedural memory
What is Semantic Memory?
- its declarative meaning it can be expressed in words
- its explicit meaning it’s available for conscious inspection
- consists of factual knowledge. It’s less personal and more about the knowledge pf the world
- may not recall when we learned these memories (they’re not time stamped)
- located in the posterior region of the cortex
What is Episodic Memory?
- its declarative meaning it can be expressed in words
- its explicit meaning it’s available for conscious inspection
- consists of memories of events, objects, people we’ve personally encountered
- usually include details about the time and place in which the events were experienced (time stamped)
- is often badly affected when brain damage causes amnesia
- located in the anterior region of the cortex
What is Procedural Memory?
- its non declarative meaning it is difficult to express in words
- its implicit meaning it’s often unavailable for conscious inspection
- action or muscle based memory
- is stored in a motor code meaning it’s difficult to express in words
- it is resistant to forgetting
-they are usually well preserved in patients with amnesia - procedural LTM located in the neocortex brain areas of primary motor cortex, cerebellum and prefrontal cortex
- LTM doesn’t need the hippocampus to function
What is the aim of Tulving’s (1989) study?
Study to prove the existence of episodic and semantic memory
What is the method of Tulving’s (1989) study?
Tulving and 5 other volunteers were injected with small amount of radioactive gold into their bloodstream. They performed 8 trials, involving 4 trials for semantic topics and 4 for episodic topics. The trials were separated by 2 minutes of rest each. Episodic memories involved personally experienced events like a holiday and Semantic topics involved historical facts or knowledge acquired through learning. Their brain was scanned using a PET scanner while they performed the separate memory tasks and blood flow monitored by radioactive detectors.
What were the results of Tulving’s (1989) study?
The two tasks gave different patterns of blood flow in the brain. Episodic memories were associated with anterior region (frontal lobe) of the cortex and semantic memories led to greater activation in the posterior region of the cortex
What is the conclusion of Tulving’s (1989) study?
Provides evidence for the different types of LTM since it shows that episodic and semantic memories are stored in different parts of the brain
Clinical evidence that supports Tulving’s view:
It shows that semantic and episodic memories are separate types since one can be damaged whilst the other one is intact.
What are the overall evaluation of different types of LTM?
- The extent to which episodic and semantic memories are different is
unclear, as although different brain areas are involved, there is also a lot of overlap between the two systems, with episodic memories often originating from semantic memories. Cohen and Squire argue that episodic and semantic memories are stored together in one LTM store that they call declarative memories in contrast to procedural memories that are non - declarative. - It may be that episodic memory differs from that of semantic in terms of different types of thinking and emotional. Episodic memories have related to them while semantic memories are associated with objective analysis of phenomenon.
- Being able to identify different aspects of LTM allows psychologists to target certain types of memory in order to better people’s lives. It has been demonstrated that episodes memory could be improved in older people with mild cognitive impairment. The trained participants performed better on a test after training than a control group. So this enables specific treatments be developed.
What was the model proposed by Baddeley and Hitch in 1970s and what is it?
Working Memory Model of Memory and its an updated version of the short term memory
Who challenged Atkinson and Shiffrin’s model and why?
They challenged Atkinson and Shiffrin’s multi store model’s concept of a unitary/single as well as passive short term memory store which only rehearsed incoming information for transfer to the long term memory.
What is the short term memory store according to Baddeley and Hitch?
A complex store made of a number of subcomponents because they found that p’s could rehearse a six digit number out aloud and perform a sentence checking task at the same time without affecting performance
An active working memory store which stores as well as manipulates information that is being processed. E.g doing mental maths
What did Baddeley and Hitch’s working model consist of?
The consists of a central executive and two slave or subsystems whose activities are controlled by the central executive. The two slave systems are Phonological Store and Visuo-spatial Sketchpad
What is The Central Executive?
- It is in overall charge.
- It is involved in higher mental processes such as mental arithmetic. It also acts as an attention system that decides which information entering from the sense organs should be attended to.
- It controls and co-ordinates the other two slave systems
- It has a limited storage capacity but is very flexible because it can process information from any of the senses
What is The Visuo-Spatial Sketchpad?
- This is also called the inner eye because it uses a visual code which represents information in the form of visual features such as size, shape and colour.
- It stores with visual/ or spatial information when required. Example when we drive along a familiar road, approach a bend, and think about the roads spatial layout beyond the bend.
- It has a limited capacity of about 3 to 4 objects
What did Logie divide Visuo-Spatial Sketchpad into?
- Visual Cache: stores visual data e.g form and colour
- The inner Scribe: records the arrangement of objects in the visual field.
What is The Phonological Loop useful for? And what are the two subsystems?
The Phonological Loop ( The Sound System) is useful for processing sound based information. The two subsystems are: the Articulatory Process and the Primary Acoustic Store
What is the Articulatory Process?
It is also called the Inner Voice because it uses an articulatory code; in which information is stored in the form it would be spoken.
It is a verbal rehearsal Loop used when, for example, when we are try to remember a telephone number for a few seconds by saying it silently to ourselves. It is also used to hold words we are preparing to speak aloud. Keeps it in working memory while they are required
It has a time based capacity. This means that its capacity is not limited by the number of items it can hold but by the length of time taken to recite to recite them. This is just like the faster you recite something into a microphone, the more words you can record on a recording tape.
What is the Primary Acoustic Store?
This is also known as the inner ear. Words we hear are stored here directly. Words we see need to be converted to speech based code via the articulatory control processes and then transferred here. It holds information in an acoustic code which lasts for about 2 seconds if it does not refresh itself via the articulatory control processes.
What is an Episodic Buffer?
The original model of the working memory was revised and a fourth component, the episodic buffer, has been added. This is a limited capacity temporary store that can access and assimilate information from a number of areas and allows the subsystems to interact.
It integrates visual, spatial and verbal information processed by the other stores and records events that are happening. So it maintains a sense of time sequencing. It can be seen as a storage component of the central executive and has a limited capacity of about 4 chunks. Also links working memory to LTM.
What is Evidence for the Working Memory Model?
a) Research into working memory has often used the Dual task performance in which participants perform two tasks at the same time. It has been found by Baddeley et al (1975) that:
• Two tasks which use different slave systems can be performed together without affecting performance on either of them
• Two tasks which make use of the same subsystem will interfere with each other’s performance.
Example:
Researchers have conducted studies in which they make the participants block their inner voice by repeating some meaningless words like the the the the out aloud. This is called articulatory suppression.
If articulatory suppression makes no difference to how well a task is performed then we conclude that the task does not use the articulatory loop.
b) Digit Span Studies: These suggest that the longer words take to say, the more difficult they are to remember because the articulatory loop holds the amount of information that you can say in 1.5 - 2 secs. This makes it easier to remember shorter words.
c) Studies of Brain Damaged Patients: Support was found from Shallice and Warrington’s (1974) case study of KF, a brain damaged patient with an impaired STM. His problem was with the immediate recall of words presented verbally, but not with visual information. This suggested he had an impaired phonological loop but an intact visuo- spatial sketchpad. This suggested he had an impaired
but his memory for visual information was largely unaffected.
This proves that there are separate
STM systems at work because it supports the existence of a separate visual and acoustic store.
However the evidence from brain damaged patients may not be reliable because it concerns
cases with patients who have had traumatic experiences.
What are Strengths for the Working Memory Model?
• This model is widely accepted as an improvement on STM - it recognises that the STM isn’t a unitary or passive store but a multi- component active working memory store.
• Evidence from experiments and case studies of brain damaged patients suggests that short term memory does involve a number of interacting sub-components. However evidence from brain damaged patients may not be reliable because it concerns unique cases with patients who have had traumatic experiences that may change the behaviour of individuals and so the findings may not explain working memory in traumatic
• It has practical applications e.g. it helps to understand that some children who find learning to read difficult may have a shorter than normal articulatory loop
What are Weaknesses for the Working Memory Model?
• There is lack of knowledge about the main component - central executive is vague and not well understood. One cannot pin point the precise function since it is involved in all tasks and cannot be excluded in an experiment. This means that the WMM hasn’t been fully explained. Critics also feel that it is not a single component but is made up of a number of parts.
• Much of the evidence provided for this model is from laboratory studies using dual task technique with a high level of control. This artificial environment makes the findings lack ecological/ external validity. It would be difficult to generalise findings from such studies to how memory works in real life since the actual tasks performed are not the ones encountered in real life.
What is Baddeley’s dual task study?
Asked participants to do either two visual tasks together (tracking a light and describing the letter F) or do a verbal and a visual task (tracking a light and a verbal task) at the same time. He found that the participants had greater difficulty doing the two visual tasks together than doing a verbal and visual task at the same time.
How does the dual task study support evidence for the working memory model?
The dual task study shows that people can perform two tasks simultaneously if they are using different parts of the working memory (slave systems)
What is the Evaluation of the Dual Task Study?
The working memory model provides an explanation for parallel processing, unlike Atkinson and Shiffrin’s MSM
Why do we forget?
- Accessibility - the information is in memory but we cannot get access to it
- Availability - the information is no longer available in our memory: it is unavailable
What is interference?
Interference: one memory disturbs the ability to recall another. This might result in forgetting or distorting one or the other or both. This is more likely to happen if the memories are similar and the two pieces of information are in conflict. Interference is less likely to occur if there is a gap between instances of learning:
What has interfernce been proposed mainly for?
Interference has been proposed mainly for forgetting in the LTM. Any forgetting in LTM is because we cannot access it even though they are available. Interference between memories makes it harder for us to locate them, and this is experienced as forgetting.
What is Proactive Interference?
where old learning affects recall of new information
What is Retroactive Interference?
where new learning affects recall of old information
What is evidence for Retroactive Interference?
Underwood & Postman (1960)
What was the aim of the Underwood & Postman study (1960)?
Aim: to find out if new learning interferes with old learning
What was the method of the Underwood & Postman study (1960)?
Method: participants were divided into two groups. Group A were asked to learn a list of word pairs i.e. cat-tree, they were then asked to learn a second list of word pairs where the second paired word was different i.e. cat - glass. Group B were asked to learn the first list of word pairs only. Both groups were asked to recall the first list of word pairs.
What was the results of the Underwood & Postman study (1960)?
Group B recall of the first list was more accurate than the recall of group A.
What was the conclusion of the Underwood & Postman study (1960)?
This shows that new learning interested with old learning supporting retroactive interference as an explanation of forgetting.
In both types of interferences when is the disruption/ confusion worse?
In both types of interferences the disruption/ confusion is worse when memories are similar.
What happens in proactive interfernce?
In proactive interference old memories make new learning more difficult to store.
What happens in retroactive interfernce?
In retroactive interference new learning overwrites previous memories which are similar.
What is a strength of Retroactive Interference theory?
Many lab experiments have been carried out to find supportive evidence for interference in memory. Most studies show that both types of interference are likely cause of forgetting from LTM.
The use of lab experiments is a strength because they are carried out under controlled conditions - any confounding variables therefore are controlled.
What are weaknesses of Retroactive Interference theory?
Most lab experiments studying interference as a theory of forgetting are designed so that the possibility of interference is maximised. The time periods between learning lists of words and recalling them is kept very short. The whole experience of learning two lists and recalling may be just 1 hour. This is a limitation because generally we don’t learn and recall information. In such a short span of time - recall is usually much later - this doesn’t reflect how we learn and remember most info in real life. So the findings lack external validing.
• Research into interference uses lab experiments based around artificial tasks such as learning word pairs. Even though learning word pairs is more realistic than learning nonsense syllables and trigrams it is still very different from the things we learn and try to remember in real life such as dates, names, time, phone number, friends number. It lacks external validity.
What research has considered interference effects in real life events to address this issue?
Aim: Baddeley and Hitch wanted to find out if interference was a better explanation for forgetting than the passage of time (decay)
Method: They asked Rugby players to try and remember the names of teams they had played so far that season, week by week. Because most players had missed games due to injury or another reason for some the last team played might have been 2-3 weeks ago. They noted whether the recall was affected by the amount of time that had passed (decay) since each game was played or the number of intervening games. interference).
Results: Forgetting was affected by the number of games a player had played in between rather than by the time that had passed since the game. So a player’s recall of a team from 3 weeks ago was better if they had played no matches since then.
Conclusions: interference plays a major role and not the time between
What are more evaluations of interference as an explanation of forgetting?
Another criticism of interference as an explanation of forgetting is that although interference effects do occur in real life they are not so frequent. Interference only really explains forgetting when 2 sets of information are similar. So interference cannot explain forgetting in majority of real life settings.
Interference effects are usually temporary and one can remember if the correct cues are provided. This suggests that Interference theory explains the forgetting of memories that are inaccessible but not those that are unavailable.
What does this explain forgetting in the LTM as?
This theory explains forgetting in the LTM as a retrieval failure: the information is available, stored in the LTM but cannot be accessed.
What does this suggest?
This suggests that when information is placed in memory, associated cues are stored at the same time. If these cues are not available at the time of recall, you might not be able to access the memories that are actually there.
What is the Encoding Specificity Principle (ESP)?
Tulving stated that if a cue is to help us to recall information it has to be present at learning and at the time of recall. If the cues are different at these times or absent at time of recall then there will be forgetting. The closer the retrieval cue to the original cue, the better the cue works.
Some cues are linked to the material to be remembered in a meaningful way. Some cues have no meaningful link.
What are the Two Types of Cue Dependent Forgetting?
- Context Dependent Forgetting
- State Dependent Forgetting
What is Context Dependent Forgetting?
This takes place when external environmental cues that were present at the time of learning are absent at the time of recall e.g. weather, location
What is evidence for Context Dependent Forgetting?
Godden and Baddeley’s (1975) experiment
What is the aim, method, results and conclusion from the Godden and Baddeley’s experiment?
Aim: They investigated the effect of environmental on recall.
Method: 18 divers from a diving club were asked to learn lists of 40 unrelated words of two or three syllables.
Results: participants recalled significantly more words if they were tested in the same environment as where they learn words.
Conclusion: this shows that if the location of learning and recall is the same then recall will be better than if the location is different thus supporting context dependent forgetting.
What are the evaluations of Godden and Baddeley’s experiment?
Real life explanations of retrieval failure due to contextual cues don’t actually explain much forgetting
In the deep sea divers study the contexts are very different. In real life you would not have learned and recalled information in such extreme environments and this would not result in much forgetting
So the findings lack external validity and so may not explain forgetting due to retrieval failure in real life.
However although context related cues appear not to have a strong effect on forgetting
Baddeley still suggests they are worth paying attention to because real Life application can be seen.
Example: the use of the context reinstatement technique in cognitive interviews - a method used to get eye witnesses to recall more information about crimes.
What studies shown similar results to Godden and Baddeley?
Abernethy found that participants after learning some material recalled it less well when tested by an unfamiliar teacher in an unfamiliar room than participants who were tested by a familiar teacher in a familiar room.
Baddeley replicated his underwater study but used a recognition test instead of getting them to recall the list. When recognition was tested there was no context dependent effect, performance was similar in all the 4 conditions. 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.
What is State Dependent Forgetting?
This is when internal psychological/ physiological cues that were present at the time of learning are absent at the time of recall
What is evidence for State Dependent Forgetting?
Carter and Cassaday (1988)
What is another that supports Carter and Cassaday’s study?
It shows that state dependant forgetting as a performance was better when in the same psychological state
What is the aim, method, results and conclusion from the Carter and Cassaday’s experiment?
Aim: examined the effects of antihistamine drugs on memory recall
Method:
Results:
Conclusion: suggests support for state dependent forgetting as performance was better when psychological state was the same when learning and when recalling.
What are the Overall evaluations?
No, This explanation only explains forgetting of material that is inaccessible but not unavailable - so a limited explanation of forgetting.
The encoding specificity principle cannot be tested since it leads to a circular reasoning. We are only making inferences about the impact of cues- they cannot be independently tested. This is a weakness of the theory.
Cues have helped recall where interference effects have been seen. This is a strength of the retrieval failure theory because This is when internal psychological/physiological cues that were present at the time of learning are absent at the time of recall.
This explanation of forgetting has been applied to explain why eyewitness accounts may not be accurate. It has also been applied to improve eyewitness testimony through the cognitive interview. It can be used to help eye witness improve their recall by using contextual cues to trigger memories. This practical application helps improve the validity of the theory by demonstrating that retrieval failure can be the reason for forgetting.
What is misleading information - leading questions?
Misleading information is incorrect information given to eyewitness usually after the event (also called post event information)
What can misleading information be given through?
- Leading Questions
- Post Event Discussion
Why do Leading Questions affect Eyewitness Testimony?
- Response- bias explanation
- Substitution explanation
What is Response- bias explanation?
This suggests that the wording of the question has no real effect on the participants memories but just influence how they decide to answer it
What is Substitution explanation?
The wording of the leading questions actually changes the participants memories
What is evidence for the Leading of Misleading Information?
Loftus and Palmer (1974)
What is misleading information - post event discussion?
The original memory of an event might be distorted through discussion of this event with other co - witnesses or with other people, it usually occurs when there is more than one witness to an event. It can also be distorted by repeated interviews.
What is the aim, method, results and conclusion from the Loftus and Palmer’s experiment 1?
Experiment 1:
Aim: to see the effect of leading questions on EWT
Method: 45 student participants were shown short video clips.
They were split into 5 groups, with 9 participants in each one
All of the participants were asked: ‘About how fast were the cars going when they ___each other. Each group was given a different verb to fill in the blank. These verbs were ‘smashed, collided, bumped, hit or contacted’.
Results: The word ‘smashed’ had the highest speed estimate in comparison to the word ‘contacted’. It’s a difference of 8.7 miles.
Conclusion: the words decreased in their intensity. The mean speed estimate also decreased, proving that the wording of a question has a big effect on the answer given.
What is the aim, method, results and conclusion from the Loftus and Palmer’s experiment 2?
Aim: to see if leading questions influence the EWT
Method: 150 student participants were shown a short film that showed a multi-vehicle car accident and then they were asked questions about it.
The participants were split into 3 groups (with 50 in each group).
One group was asked:
‘How fast were the cars going when they hit each other?’
The second was asked: ‘How fast were the cars going when they smashed into each other?’
The third group was not asked about the speed of the vehicles
One week later, all participants returned and were asked: ‘Did you see any broken glass?’ There was no broken glass in the film.
Results: those who thought the car was travelling faster were more likely to have thought they saw broken glass.
Conclusion: it’s inaccurate and changes according to the question. Shows that leading questions do change the actual memory a participant had for an event supporting that misleading information can lead to inaccuracies in EWT
Why does post event discussion lead to eyewitness testimonies becoming contaminated?
They combine misinformation from other witnesses with their own memories.
What is Source Monitoring?
When co- witnesses discuss a crime, they mix (mis)information from other witnesses with their own memories and confuse the source
What is Memory Conforming?
Memory distorted through discussion - for either social approval or belief that other witnesses are right
What is Gabbert et al study?
Gabbert et al (2003) 2 groups of Ps watched the same crime scene but from different angles which allowed them to see different details of the same scene. The Ps were led to believe that they had watched the same video. Then Ps were asked to recall the event either alone or in pairs. An individual recall test was then administered to examine the effects of co-witness discussion on subsequent memory reports.
71% of witnesses who had discussed the event mistakenly recalled aspects of the event they had not seen in the video but had picked up in the discussion with their co-witness. The figure in the no discussion control group was 0%.
What does Gabbert et al study suggest?
This study suggests that the combination of information between witnesses leads to incorrect recall because of the influence of a second opinion, memory capacity.
What are weaknesses of research into eyewitness testimony?
A limitation of research into eye witness testimony is that they lack external validity due to multiple reasons.
A weakness of Loftus and Palmer’s experiment is that it used artificial materials under controlled conditions. Participants watched film clips of accidents, a very different experience from witnessing a real accidents. Real accidents have more emotional impact and are more stressful. This shows that artificial tasks tell us very little about how leading questions affect EWT in real
crimes or accidents.
What are more weaknesses into research into eyewitness testimony?
Another weakness of experiments into impact of misleading information on EWT is that participants in such experiments know that their responses do not have serious consequences, whereas in the real world eye witnesses are aware that their responses influence the trial. Real eye witnesses’ search their memory with more effort because their testimony could result in a conviction. Therefore accuracy of eye witness testimony would be greater in the real world than in research studies.
A third limitation is that research participants usually want to be helpful and attentive. So when they are asked a leading question and don’t know the answer, they guess (especially for yes/no answers). This means these studies suffer from demand characteristics. This challenges the validity of EWT research since the answers given may not really reflect their memories and so do not measure the impact of misleading information on accuracy of EWT.
What is the real life research that contradicts research studies in to impact of misleading questions on EWT?
Yuille and Cutshall (1986)
What is Yuille and Cutshall (1986)?
In a real life crime a gun shop owner shot a thief dead. There were 21 witnesses, 13 agreed to participate. They were interviewed again after 4-5 months and their accounts were compared to the police interviews given at the time of the shooting. Ps were able to give an accurate recall of the event compared to initial reports.
Witnesses also rated how stressed they felt at the time of the incident.
Results: Witnesses were very accurate and there was little change after 5 months. Participants who reported the highest level of stress were the most accurate.
Conclusion: when a participant feels stressed whilst giving an EWT. They are more likely to be the most accurate. After 5 months the EWT was still very accurate and only a little changed.
Did Yuille and Cutshall study support Loftus and Palmers study? What are the factors?
It doesn’t support the findings because they weren’t affected by leading questions. Have high external validity since findings can be generalised similar situations.
Factors that might explain the difference in results:
- EWT in the real world remember their testimony has serious consequences.
- More emotional impact in a real life accident.
- May not be demand characteristics in world settings.
What is another issue relating to age?
It has been found that although older people were less accurate than younger people when giving eye witness reports. However all age groups were more accurate when identifying people of their own age group (own age bias). Research studies often use younger people as the target to identify. The issue with this is that the findings may not be valid. Recall of older people may be better than what has been found if the targets had been people similar to their own age.
What are the strengths?
Research into impact of misleading information on accuracy of EWT has real life applications:
- warns police to be careful about how they first questions when interview witnesses.
- warns the justice system of problems with EWT and suggests way of improving testimonies. - warns participants that anything that they hear from a co- witness is second hand information - they should recall only their own memory of the event.
What are the ethical issues related to investigating impact of misleading information through lab experiments?
Use of deception - participants led to believe that study was to measure the ability to estimate speed of moving vehicles but they were actually measuring how estimates were influenced by leading questions which meant that there was no informed consent since information was withheld.
Solution: debrief participants at the end of the study and tell them everything.
What is anxiety?
Anxiety is a state of emotional and physical arousal. It is an unpleasant emotional state where we fear something bad is about to happen.
When do people normally become anxious and what is it accompanied by?
People often become anxious when they are in stressful situations. This is usually accompanied by physiological arousal i.e. pounding heart, shallow breathing and sweating. Anxiety can have positive or negative effects on recall.
What is the negative effect of anxiety?
Anxiety creates a physiological arousal in the body which prevents us from paying attention to important cues and so recall is worse.
What is Weapon Focus?
When people are in a stressful situation their attention is narrowly focused towards the most fearful aspect of the situation - the weapon because it is a source of high anxiety and away from the other details.
What is the Johnson and Scott study?
Participants were told they were taking part in a lab study. While seated in a waiting room participants heard an argument in the next room.
In the low anxiety condition: a man then walked through the waiting area, carrying a pen and with grease on his hands.
In the high anxiety condition: the argument was accompanied by the sound of breaking glass. A man then walked out of the room, holding a paper knife that was covered in blood.
Partipants were then asked to pick out the man from a set of 50 photos.
Results: 49% of participants who saw the man carrying the pen were able to identify him. 33% of participants who saw the man carrying the blood covered knife were able to
identify him.
Conclusion: when you see danger, you remember less -> negative effect on eyewitness testimony
What is the ‘Tunnel Theory’
This argues that the witness’s attention is narrowed to focus on the weapon because it is the source of danger and anxiety.
What is a weakness of Johnson and Scott’s study?
A limitation of Johnson and Scott’s study is that may have tested unusualness or surprise and not anxiety. This can be seen through a study in which Pickel used scissors, handgun, a wallet and raw chicken as handheld items in a hair dressing salon. EWT accuracy was poorer for higher unusualness and not anxiety - for raw chicken and handgun. So we
do not know specifically about the effects of anxiety on EWT.
Another limitation is that there are ethical issues in this research area. They don’t challenge the findings but they do raise questions about conducting such research. The studies create anxiety. This is unethical since they subject people to psychological harm for research.
Solutions:
• Use real life studies- interview people who have already witnessed an event
• debrief
• right to withdraw
What are more weaknesses of Johnson and Scott’s study?
A further limitation Most lab studies looking into the impact of anxiety on EWT show particpants a filmed (usually staged) crime. Most of these participants are aware that they are watching a filmed crime for a reason to do with the study.
Might lead to demand characteristics since they would have worked out that they are going to be questioned about what they have seen - may change answers. Decrease validity of findings.
Furthermore, field studies sometimes lack control. Researchers interview eye witnesses sometime after the event. There could be other things that might happen in between such as
- discussions with other people about the event
- accounts they might have read/yean in media
- reduce the validity of the supportive evidence
This will make it difficult to assess whether the accuracy of the recall is affected by these other factors or by anxiety reducing the validity of the supportive evidence.
What is positive effect of anxiety on recall?
The stress of witnessing a crime/accident creates anxiety through physiological arousal in the body. The fight or flight response is triggered which increases our alertness and improves our memory.
An evolutionary argument suggests that it would be adaptive to remember events that are emotionally important so you can identify similar situations in the future and recall how to respond
What happened according to Yerkes- Dodson Law?
According to the Yerkes-Dodson Law, the relationship between emotional arousal/ stress and performance is curvilinear not linear - looks like an inverted U
This inverted U theory states that performance will increase with stress but only to an optimum level and beyond that it will suffer drastically.
What happens when it is applied to eyewitness testimony?
• Low levels of anxiety = low performance
• Optimum levels of anxiety = high performance
• Very high anxiety = low performance
What is the evaluation of Inverted U explanation?
Anxiety is difficult to define because it has many elements-such as cognitive, emotional, psychological
and behavioural. The inverted U it is too simplified. It links anxiety to just physiology and does not account for the other factors. E.g. Accuracy of recall may be affected by fear ( emotional factor)
How can EWT be improved according Fisher and Gieselman?
Fisher and Gieselman argued that EWT can be improved if the police used better techniques based on psychological insights into how memory works.
What is the Cognitive Interview?
The Cognitive interview is a method of interviewing eye witnesses to help them retrieve more accurate memories.
What are the 4 basic techniques that the Cognitive Interview use?
- Report everything
- Reinstate the context
- Recall in reverse order
- Recall from a changed perspective
What is the aim of the Cognitive Interview?
rethink more accurate memories
What is Context Reinstatement?
Witnesses should return to the original crime scene in the mind and use your senses. E.g. what the weather is like. This is related to context, dependent, forgetting.
What is Report Everything?
Witnesses are encouraged to include every single detail of the event (if it seems relevant). Trial details may be important and trigger other important memories.
What is Recall from a Changed Perspective?
Witnesses must recall memories from another perspective. E.g. how it appeared to the other witnesses. This is done disrupt the effect of expectations and schemes on recall.
What is Recall in Reverse Order?
Events should be recalled in a different chronological order to the original sequence. E.g. from the trial point back to the beginning. This is done to prevent people reporting their expectations of how the event must have happened rather than the actual event. It also prevents dishonesty.
Why did the Cognitive Interview get developed?
It got developed because cognitive interviews showed that officers lacked social skills - added social and communication skills to training.
What are the 5 additional features of the Enhanced Cognitive Interview?
- know when to establish eye contact
- adapt questions to suit understanding of individual witnesses
- offer comments to help clarify statements
- encourage the witnesses to speak slowly, with pauses
- try to reduce eyewitness anxiety - encourage them to relax, establish rapport
Modified Cognitive Interview
- To be used with children which stresses on building a rapport between the interviewer and witness and removes the demand characteristics as children are seen to be too young to effectively
empathise with others. - Police forces also use modified CI’s - shortened versions which take less time.
Geiselman et al (1988)
Trainee police officers were shown police training videos of crime. Two days later they were interviewed either by experience private investigators or experienced CIA agents using either the standard or the cognitive interview. Significantly, more factually correct information was retrieved with cognitive interview without as much confabulation or mistakes as when the standard interview was used. This suggests that the cognitive interview is a better type of interview to use than the standard interview as it yields more information and the recall is more accurate.
Fisher et al (1989)
This was a study of real life cognitive interview performance. The researchers trained police detectives in Florida in the use of the cognitive interview and compared their interview performing before and after training. After training, the detectives gained as much as 47% more useful information from witnesses to real crimes compared to when they and been using standard interview techniques.
What are weaknesses of cognitive interview as a method to improve the accuracy of eyewitness memory?
Police are reluctant to use Cl because it is more time consuming than the standard police interview because you need to establish rapport with the witness and allow them to relax. It may also require special training. Many forces may not be able to provide more than a few hours of training and therefore it may be unlikely that a proper version of Cl be used.
Another limitation is that the techniques used in Cl aim to increase the amount of correct information recalled but they also may increase the recall of incorrect information. Kohnken’s research found an 81% increase of correct information but also a 61% increase of incorrect information when the enhanced Cl was used compared to the standard interview. The increased rate of incorrect information recalled may lead to false consciousness leading to incorrect reporting of the crime which leads to false convictions.
What are strengths of cognitive interview as a method to improve the accuracy of eyewitness memory?
On a positive note, It has been found that although all the 4 techniques used in Cl are valuable since each technique on its own produced more information than the standard police information. However there is evidence that using a combination of reporting everything and context reinstatement led to better recall than any other technique. This implies that some aspects of Cl are more useful than others and therefore at least these two elements should be used to improve police interviewing eye witnesses. This will increase the credibility of the Cl among police officers.
Another strength of the cognitive interview is that its techniques are based on psychological research into how human memory works. E.g. report everything and reinstate the
context are both based on Tulving’s encoding specificity. These techniques therefore are not just useful in recalling crimes but you can use them to recall any event you have witnessed and want to remember more about.
What is an advantage of many variations of the CI being used?
It’s flexible and can be adapted to different circumstances
What is a weakness of many variations of the CI being used?
Difficult to compare effectiveness
What technique of the CI could mislead the witnesses into speculating about the event witnessed and is therefore less frequently used?
Change of Perspective - more usual when interviewing video witnesses because they may be more cautious about reporting information -> using the technique report everything may overcome this problem.
