Memory Flashcards
Define short term memory
Memory for events in the present or immediate past
What is long term memory?
Memory for events that have happened in the more distant past
How is LTM and STM distinguished?
Capacity, duration & coding
Define capacity
Capacity concerns how much data can be held in a memory store. STM has limited capacity whereas LTM has potentially infinite capacity
Who researched using digit span to asses the short term memory capacity.
Joseph Jacobs (1887)
What did Joseph Jacobs find the average digit span to be ?
7 for letters
9 for numbers
Who came up with the “magic number” in relation to STM capacity and what is it?
George Miller (1956)
7 + or - 2 items
Who studied the duration of the STM?
Lloyd and Margaret Peterson (1959)
How did the Petersons study the duration of the STM?
24 students given a consonant syllable and a 3 digit number (e.g THX 512). They were asked to recall the consonant syllable after a retention interval during which they had to count backwards from their 3 digit number. The longer the interval the less people were able to remember.
Who studied the duration of the LTM?
Harry Bahrick
What did Bahrick do to investigate the duration of the LTM?
Tested 400 people on their memory of their classmates using a photo recognition test. The longer it was after graduation the more they were able to remember.
Evaluation of the STM?
- STM not as extensive as first thought
- size of the chunks affects how many chunks you can remember
- individual differences (capacity not the same for everyone)
- testing of the STM does not reflect everyday memory activities
- results may be due to displacement
How is information coded in the STM?
Acoustically
How is information coded in the LTM?
Semantically
Who researched coding in both the LTM and the STM?
How did they do it ?
Baddeley (1966)
Used words lists
Evaluation of coding?
- STM may not be exclusively acoustic (visual codes may be used)
- LTM may not be exclusively semantic (may be related to visual categories)
How is information encoded in the sensory register
In its original form
What is the capacity of the sensory register?
At least 12 items
What is the duration of the sensory register?
A few milliseconds
What is the multi-store model and why is it called that?
It is a model of memory that is called ‘multi store’ because it consists of three of 3 memory stores linked to each other by the processes that enable transfer of information from one store to the next
Who first described the multi store model?
Atkinson and Shiffrin (1968)
What is the sensory register?
Place where information is held at each of the senses (eyes, nose etc) and the corresponding areas of the brain
The sensory registers are constantly receiving information
What is the duration of the sensory register?
A few milliseconds
How is information passed from the sensory register to the STM?
If attention is focused on the sensory stores then data is stored in the STM
What kind of information is stored in the STM?
Information that can be stored for immediate tasks e.g remembering directions to a friends house
How can you prevent information being lost from the STM?
STM has a limited duration so Rehearsal helps to avoid decay/displacement
Define displacement
If new information enters the STM pushing out (displacing) the the original information
Why does displacement occur?
STM has a limited capacity
How is a LTM created?
A lot of repetition of the data will eventually create s LTM
Atkinson and Shiffrin proposed a relationship between rehearsal and…
Strength of the LTM
The more information is reversed the better it is remembered (maintenance rehearsal)
What kind of duration and capacity does LTM have?
Potentially unlimited
Evaluation: (multi-store model of memory)Strengths of the MSM (separate stores)
- Lab studies on capacity, duration and coding support the existence of a separate long and short term memory store which is the basis for the MSM
- studies using brain scanning techniques (differences between STM and LTM)
- different areas of the brain active when completing STM/LTM tasks
Evaluation:(multi-store model of memory) Limitations of the MSM (overly simplistic)
- suggests that STM and LTM are single unitary stores
- research does not support this, there may be subsections within stores
- differ not only in capacity/ duration but also kind of memories stored
- research shows there are a number of qualitatively different types of LTM
Evaluation: (multi-store model of memory) Case studies on memory:
Clive wearing
- psychologists have also shown that different areas of the brain are involved in STM and LTM from their study of individuals with brain damage
- one case involved a man referred to as HM (Scoville and Milner 1957)
- his brain damage was caused by an operation to remove the hippocampus from both sides of his brain to reduce the severe epilepsy he had suffered
- HM personality and personality remained intact but he could not form new LTM although he could remember things from before the surgery
Evaluation: (multi-store model of memory) long term memory involves more than maintenence rehearsal
- Craik and Lokhart (1972) suggested that enduring memories are created by the processing that you do, rather than through maintenence rehersal; things that are processed more deeply are more memorable just because of the way they are processed.
- ‘deep’ means doing more complicated things with the item to be remembered rather than just repeating it
- Craik and Tulving (1975) gave participants a list of nouns (e.g. ‘shark’) and asked a question that involved shallow or deep processing- asked whether a word was printed in capital letters (shallow processing) or asked whether a word was printed in capital letters or asked whether a word fitted in a sentence (deep provessing).
- the participants remembered more words in the task involving deep processing rather than shallow processing
- this ‘deep’ or elaborate processing is a key process in creating long term memory
What is an alternate (extension) model of the multi store model of memory?
The working memory model
What aspect of memory does the working memory model address?
Short term memory/immediate memory
Who is the researchers concerned with the working memory model?
Baddeley & Hitch (1974)
What main thing did Baddeley and Hitch think about the STM?
STM was not just one store but a number of different stores
Why did Baddeley and Hitch think that STM consisted of a number of different stores?
- if you do two things at once (dual task performance) and they are both visual tasks you perform less well than if you do them separately
- if you do two things at the same time and one is visual and the other involves sound, then there is no interference. You do them well simultaneously as you do them separately
What did Baddeley and Hitch suggest and how does it form the basis of WMM?
- That there is one store for visual processing and a separate store for processing sounds
- this formed the basis of WMM where ‘slave systems’ are organised by a central executive
Briefly describe the central executive
Monitors and coordinates all other mental functions in working memory
Explain the function of the central executive
- The function of the CE is to direct attention to particular tasks, determining at any time how the brains resources are allocated into tasks
- data arrives from the senses or form long term memory
- (the CE has a very limited capacity; in other words it can’t attend to too may things at once and has no capacity for storing data)
The phonological loop is also referred to as…
The inner ear
What is the function of the phonological loop?
Codes speech sounds in working memory, typically involving maintenance rehearsal.
Why is it called the ‘phonological loop? :
It involves a lot maintenance rehearsal (repeating the words over and over again)
Describe the properties of the phonological loop
- it has a limited capacity
- PL deals with auditory information and preserves the order of information
Baddely (1986) further subdivided this loop into:
- the phonological store which holds the words you hear
- an articulatory process which is used for words that are heard or seen. These words are silently repeated (looped) like an inner voice. (a form or maintenance rehearsal)
What is the function of the viso-spatial sketchpad?
Codes visual information in terms of separate objects as well as the arrangement of these objects in one’s visual field
State some properties of the viso-spatial sketchpad
VSS us used when you have to plan a spatial task (like getting from one room to another, or counting the number of windows in your house) visual/spatial information is temporarily stored here.
What is visual information?
What things look like
What is spatial information?
The physical relationship between things
What stores information about visual items?give examples
Visual cache
E.g. Form and colour
What did Logie suggest about the viso-spatial sketchpad
It can b en divided into a visual cache and an inner scribe
What does the inner scribe do?
Stores the arrangement of objects in the visual field
What is the episodic buffer?
Recieves input from many sources, temporarily stores this information and then integrates it in order to construct a mental episode of what is being experienced
What did Baddely add to the WMM in 2000
The episodic buffer
Why did Baddely add the episodic buffer?
He realised the model needed a general store
The phonological loop and viso-spatial sketchpad deal with…
Processing and temporary storage of specific kinds of information
The storage capacity of the central executive
The central executive has no storage capacity so there is nowhere to hold information that relates to both visual and acoustic information
The capacity of the episodic buffer
Limited capacity
What does the episodic buffer do? (in relation to central executive and phonological loop)
The episodic buffer integrates information information from the central executive, the phonological loop and the viso-spatial sketchpad. It also maintains a sense of time sequencing- basically recording events (episodes) that are happening.
How is the episodic buffer related to the LTM?
The episodic buffer sends information to the LTM
Evaluation: (working memory model) strengths- dual task performance
- the main reason for developing the WMM was to account for dual task performance, described on the facing page.
- Hitch and Baddely supported the existence in one such study.
- task 1occupied the central executive (e.g. Participants were given a statement B is followed by A and shown two letters such as AB and asked to say true or false )
- task 2 involved both the central executive and the articulatory loop
- this demonstrates the dual task performance effect and shows that the central executive is one of the components of working memory
Evaluation: (working memory model) strength- evidence from brain damaged patients
- studies of individuals with brain damage also support the WMM
- Shallice and Warrington studied a man called KF whose 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 (such as a phone ringing)
- thus the brain damage seemed to be restricted to the phonological loop
- another patient SC had generally good learning abilities with the exception of being unable to learn word pairs that were presented out loud
- this suggests damage to the phonological loop
- another patient LH who had been involved in a road accident performed better on spatial tasks than those involving visual imagery.
- This suggests separate visual and spatial systems
Evaluation: (working memory model) Limitations- the cental executive
-there is some concern about the central executive. Especially to do with what exactly it is. The answer appears to be that it allocates resources and is essentially the same as ‘attension’
- some psychologists feel this is too vague and doesn’t really explain anything. Critics also feel that the notion of a single central executive is wrong and that there are probably several components
- (Ealinger and Damasio studied EVR who had had a cerebral tumour removed. He performed well on tests requiring reasoning,which suggested that his central executive was intact; however he had poor decision making skills (e.g. he would spend hours deciding sure to eat)
Which suggests that in fact his central executive is not wholly intact
- the account offered of the central executive us unsatisfactory as it is probably more complex than currently represented
Evaluation: (working memory model) Limitations- evidence from brain damaged patients
- some of the key evidence of the WMM comes from case studies of Individuals who have suffered serious brain damage
- there are a number of problems with using such evidence
- first of all the process of brain injury is traumatic which may in itself change behaviour so that a person performs worse on certain tasks
- secondly such individuals may have other difficulties such as difficulties paying attention and therefore underperform on certain tasks
Evaluation: (working memory model) evidence for the phonological loop articulatory process
- the phonological loop explains why the word-length effect occurs (the fact that people cope better with short words than long words in working memory (STM).
- it seems that the phonological loop holds the amount of information that you can say in 2 seconds (Baddeley)
- this makes it hard to remember long words like ‘association’ and ‘representative’ compared to shorter worlds like ‘harm’ and ‘twice’
- the longer words can’t be rehersed on the phonological loop because they don’t fit
- however the word length effect disappears is given an articulatory suppression task for example if you are asked to say ‘the the the’ while reading the words. This representative task ties up the articulatory process and means you can’t reherse the shorter words more quickly than the longer ones l so the word length effect disappears
- this is evidence for articulatory process
Define cues
- Things that serve as a reminder
- they may meaningfully link to the material to be remembered or may not be meaningfully linked, such as environmental cues (a room) or cues related to your mental state (being sad or drunk)
What is retrieval failure?
- occurs due to the absence of cues
- an explanation for forgetting based on the idea that the issue relates to being able to retrieve a memory that is there (available) but not accessible.
- retrieval depends on cues
Brief description of retrieval failure
Forgetting in LTM is mainly due to retrieval (lack of accessibility rather than availability). This is the failure to find the item of information because you have insufficient clues or clues
Explanations for forgetting (AO1): (retrieval failure theory) What is encoding specificity principle?
• Tulving an Thomson (1973) proposed that memory is most effective if the information that was present at encoding was present at the time of retrieval
- the encoding specificity principle further states that a cue doesn’t have to be exactly right but the closer the cue is to the original item the more useful it will be
Study: Tulving and Pearlstone
-demonstrated the value of retrieval cues in a study where participants had to learn 48 word belonging to 12 categories
- each word was represented as a category + word (e.g Fruit-apple)
- there are two different recall conditions
- participants either had to recall as many words as they could (free recall) or they were given cues in the form of category names (cued recall)
- free recall-> 40% -cued recall-> 60%
- this is evidence that cues have been enclosed at time of learning and have a meaningful link to the learning material
- any other type of cue not related to the learning material-> sometimes being reminded of a place/particular mood can act as a trigger (cue) to help access memory
Explanations for forgetting (AO1): (Retrieval failure theory) Give an example of a involving context dependent forgetting: (Abernethy 1940)
*Ethel Abernethy (1940):
- She arranged for a group of students to be tested before a class began-> they were tested each week
- some were tested in their teaching room by their usual instructor
-others tested by a different instructor
- others tested in a different room
- others tested in a different room, same instructor
~ Those tested in the same room by the same instructor performed best
~ Familiar things acted as memory cues
~ Abernethy also found that superior students were least affected by the changes and inferior students the most
Explanations for forgetting (AO1): (Retrieval failure theory) Give an example of involving context dependent forgetting: (Baddeley 1975)
- Godden Baddeley (1975)
-investigated the effect of contextual cues - The researches recruited scuba divers as participants and arranged for them to learn a set of words either on land or underwater
- Subsequently they were tested on land or underwater
- (4 experimental conditions)
~Results showed that highest recall when initial context matched recalling environment e.g learning underwater and recalling underwater
Explanations for forgetting (AO1): (Retrieval failure theory) What is state dependent forgetting?
Give an example of a study that demonstrates state dependent forgetting
- The mental state you are in at the time of learning can also act as a cue.
*Goodwin asked male volunteers to remember a list of words when they were either drunk or sober - Those drunk had 3x the UK drink driving limit
- The participants were asked to recall the lists 24 hours when some were sober and other had to get drunk again
~ Information learned when drunk or sober is more available in the same state later
Evaluation: retrieval failure (a lot of research support)
- Lots of research to support the importance of retrieval cues on memory
- research includes laboratory, field and natural experiments thus has relevance to everyday memory experiences
- Tulving & Pearlstone
- Abernethy
- Goodwin
Evaluation: retrieval failure (real-word application)
- an application of the research is to use it to improve recall when you jneed to e.g for exams
- Abernethy’s research suggests that you should revise in the room that you will be taking the exams
- this may be unrealistic but you can use imagination to achieve this
- Smith (1979) showed that by just thinking of the room was as effective as actually being in that room at the time of retrieval
Evaluation: retrieval failure (retrieval cues do not always work)
- cues may not be very effective in increasing exam performance
- information you are learning is related to a lot more than just cues
- In most of the research on context effects, participants are learning words lists but during normal learning about more complex associations that are less easily triggered by cues
-OUTSHINING HYPOTHESIS, a cues effectiveness is reduced by the presence of better cues - according to Smith and Vela context effects are largely eliminated when learning meaningful information
•therefore retrieval cues don’t explain everything
Evaluation: retrieval failure (danger of circularity)
- James Nairne claims that the relationship between encoding cues and later retrieval is not the cause that it was primarily suggested to be but in fact just correlation (associated with retrieval)
- Baddeley
Evaluation: retrieval failure (retrieval failure explains interference effects)
- Tulving and Psotka demonstrated that apparent interference effects are actually due to the absence of cues.
- Participants were given six different categories
- After each list was presented the participants were given the category names and again asked to record as many words as they could remember (free recall)
- After all the lists were presented the participants were given the category names and again asked to recall all the words from all the lists (cued recall)
- Some participants only learned one list, others learned two and so on
- According to interference theory, the more lists a participant had to learn, the worse their performance would become
- This was what Tulving and Psotka found ]- evidence of retrospective interference
- However when participants were given cued recall the effects of interference disappeared
-Participants remembered about 70% of the words regardless of how many lists they had been given. This shows that information is available and cues help to access it
~Retrieval failure is a more important explanation of forgetting then interference
Define interference theory
- An explanation for forgetting in terms of one memory disrupting the ability to recall another
- This is most likely to occur when the the two memories have some similarity
What is proactive interference?
Past learning interferes with current attempts to learn something
What is retroactive interference?
Current attempts to learn something interferes with past learning
Explanations for forgetting (AO1): (Interference theory) Retroactive interference
- George Muller and his student (Pilzecker) were the first to identify retroactive interference effects
- They gave participants a list of nonsense syllables to learn fro 6 minutes and then, after a retention interval, asked participants to recall the lists
- Performance was not as good if participants had been given an interval task between initial learning and recall (they were shown 3 landscape paintings and asked to describe them)
- The intervening task produced retroactive interference because the later task interfered with what had been previously learned
Explanations for forgetting (AO1): (Interference theory)m
Proactive interference
- Benton Underwood showed that proactive interference could be equally significant
- He analysed the findings from a number if studies and concluded that when participants have to learn a series of words encountered later on in the sequence as well as lists of words encountered earlier on
- Overall, Underwood found that, if participants memorised 10 or more lists then, after 24 hours, they remembered about 20% of what they learned
- If they only learned one list recall was over 70%
Explanations for forgetting (AO1): (Interference theory) Similarity of test materials
- In another early study McGeoch and McDonald experimented with effects of similarity of materials
- They gave participants a list of 10 adjectives (list A)
- Once these learned there was then a resting interval of 10 minutes during which they learned list B followed by recall
- If list B was a list of synonyms for list A , recall was poor (12%); if list B was nonsense syllabus this had less effect (26% recall); if list B was numbers which had the least effect (37% recall). This shows that interference is strongest the more similar the items are. Only interference, rather than decay, can explain such effects
Explanations for forgetting (AO1): (Interference theory) A real-world study
- Baddeley and Hitch investigated interference effects in an everyday setting of a rugby players recalling the names of teams they had played against over a rugby season.
- Some players had played in all of the games in the season whereas others missed some games because of injury
- The time interval from start to end of season was the same for all players but the number of intervening games was different for each played because of missed games
- If decay theory is correct then all players should recall a similar percentage of the games played because time alone should cause forgetting
- If interference theory is correct then those players who played most games should forget proportionally more because of interference- which is what Baddeley and Hitch found, demonstrating the effect of interfernce in everyday life
Evaluation: Interference theory (Research is quite artificial)
- There is considerable evidence that supports both pro- and retroactive interference
- However, one issue is that most of this research has been lab based and often used rather artificial lists of words and/ nonsense syllables
- Thus findings may not relate to everyday uses of memory, which tends not to involve words lists
- Participants may lack motivation to remember the links in such studies and this may allow interference effects to appear stronger than they really are
~ Low ecological validity
~Counterargument-> interference effects have been observed in everyday situations
Evaluation: interference theory (Interference only explains some situations of forgetting)
- Although interference effects do occur in real life, they do not occur very often
- Rather special conditions are required for interference to lead to forgetting
- The two memories need to be quite similar
- For this reason, interference is considered a relatively unimportant explanation for forgetting
- Anderson concluded that there is no doubt interference plays a role in forgetting, but how much of forgetting can be explained by interference is unclear
Evaluation: Interference theory ( Accessibility rather than availability)
- Researchers have often questioned whether interference effects actually cause a memory to disappear or whether interference effects are just temporary
- Ceraso found that, if memory was tested again after 24 hours, recognition (accessibility) showed considerable spontaneous recovery, whereas recall (availability) remained the same
- This shows that interference occurs because memories are temporarily not accessible rather than having actually been lost (unavailable)
- The study by Tulving and Psotka also supports this finding that interference affects availability rather than accessibility.
Evaluation: Interference theory (Real-world application to advertising)
- There is considered body of research on the effects of interference when people are exposed to adverts from competing brands, within a short time period
- For example Danaher found that both recall and recognition of an advertisers message were impaired when participants were exposed to two advertisements for competing brands each week
- This is a serious problem considering the amount of money that advertisements spend only to have the effect of their advertisement diluted by interference
- Danaher suggests that one strategy might be enhance the memory trace by running multiple exposures to an advertisement on one day rather than spread these out over a week
- This results in reduces interference from competitors’ advertisements
Evaluation: Interference theory (Individual differences)
- There is evidence that some people are less affected by proactive interference than 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
Accuracy of eyewitnesses testimony: effects of anxiety
- Stress and anxiety has a negative effect on memory as well as performance generally
- Automatic skills are not affected be stress/ physiological arousal but performance on complicated cognitive tasks
Accuracy of eyewitness testimony: (Effect of anxiety)
Key study: Johnson and Scott (1976)
- A different account of why anxiety might reduce the accuracy of EWT is the weapon focus effect
- This is the view that a weapon in a criminals hand distracts attention because of the anxiety it creates from other features and therefore reduces the accuracy of identification
Accuracy of eyewitness testimony: (Effect of anxiety)
Key study: Johnson and Scott Procedure
- To test this effect Johnson and Scott asked participants to sit in a waiting room where they heard an argument in an adjoining room and then saw a man through the room carrying either a pen covered in grease (low anxiety condition) or a knife covered in blood (high anxiety weapon focus condition)
- Participants were later asked to identify the man from a set of photographs
Accuracy of eyewitness testimony: (Effect of anxiety)
Key study: Johnson and Scott Findings
- The findings supported the idea of the weapon focus effect
- Mean accuracy was 49% in identifying the man in pen condition, compared with 33% accuracy in the knife condition
- Loftus showed that anxiety does focus attention on central features of a crime (e.g. a weapon)
- The researcher monitored eyewitness’ eye movements and found that the presence of a weapon caused attention to be physically drawn towards the weapon itself and away from other things such as the persons face
Accuracy of eyewitness testimony: Anxiety has a positive effect on accuracy
- There is an alternative argument that says high anxiety/ arousal creates more enduring and accurate memories
- For example, there is an evolutionary argument that suggests it would be adaptive to remember events that are emotionally important so that you could identify similar situations in the future and recall how to respond- such as what you did last time when you escaped from a lion
- Christianson and Hubinette found evidence of enhanced recall when they questioned 58 real witnesses to bank robberies in Sweden
- The witnesses were either victims (bank teller) or bystanders (employee or customer) i.e. high and low anxiety respectively
- The interviews were conducted 4-15 months after the robberies
- The researchers found that all witnesses showed generally good memories for details of the robbery itself (better than 75% accurate recall)
- Those witnesses who were most anxious (the victims) had the best recall of all
- Christianson in a review of research, concluded that memory for negative emotional events is better than for neutral events, at least for the central details
Accuracy of eyewitness testimony: Resolving the contradiction
- Kenneth Deffenbacher reviewed 21 studies of the effects of anxiety on eyewitness memory
- He found that 10 of these studies had results that linked higher arousal levels to increased eyewitness accuracy while 11 of them showed the opposite
- Deffenbacher suggested that the Yerkes- Dodson effect can account for this apparent inconsistency
- According to this principle there would be occasions when anxiety/ arousal is only moderate and then eyewitness accuracy would be enhanced
- When anxiety/ arousal is too extreme then accuracy will be reduced
Evaluation: Accuracy of eyewitness testimony: anxiety (Weapon focus may not be caused by anxiety)
- Pickel proposed that the reduced accuracy of identification due to the weapon focus effect 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)
- identification was least accurate in the high conditions rather than high threat
- This supports the view that view that the weapon focus effect is related to surprise rather than anxiety
Evaluation: Accuracy of eyewitness testimony: anxiety (real life versus lab studies)
- One of the strengths of the study by Christianson and Hubinette was that it was a study of anxiety in the context of a real crime
- It may well be the case that lab studies do not create the real levels of anxiety experienced by a real eyewitness during an actual crime
- Deffenbacher agree with this but found, from a review of 34 studies are associated with an even greater loss in accuracy, which is at odds with the result from Christianson and Hubinette
- Fazey and Hardy’s model offers a way to accommodate this
Evaluation:Accuracy of eyewitness testimony: anxiety (No simple conclusions)
- The study by Christianson and Hubinette concerned a violent real-life crime
- Many other studies of anxiety and accuracy of identification, even the real-life ones, did not involve violence
- Like Christianson and Hubinette, Halford and Milne found that victims of violent crimes were more accurate in their recall of crime scene information than victims of non-violent crimes
- This shows that there is no simple rule about the effect of anxiety on accuracy of eyewitness testimony
Evaluation: Accuracy of eyewitness testimony: anxiety (Individual differences)
- It has been suggested that one key extraneous variable in many studies of anxiety is emotional sensitivity
- A study by Bothwell
- Participants were assessed for neuroticism- a personality characteristic where individuals tend to become anxious quite quickly
- Participants were tested and labelled as ‘neurotic’ or ‘stable’ (less emotionally sensitive)
- In this study it was found that the ‘stable’ participants showed rising levels of accuracy as stress levels increased whereas the opposite was true for neurotics- their accuracy levels decreased as stress increased
- Deffenbacher point out that the modest effect sizes shown in many studies of anxiety may be the result of averaging out how low accuracy and high accuracy scores of sensitive and non-sensitive participants respectively
Evaluation: Accuracy of eyewitness testimony: anxiety (An alternative model)
- Fazey and Hardy suggested a more complex relationship between anxiety and performance than the Yerkes-Dodson model
- Their catastrophe theory predicts that when physiological arousal increases beyond the optimum level, the inverted-U hypothesis predicts a gradual decrease in performance
- However, Fazey and Hardy observed that in fact there is sometimes a catastrophic decline, which they suggest is due to increased mental anxiety (worry)- the inverte6d U only describes increases in physiological anxiety
- Deffenbacher believes this offers a better fit with research findings, especially those of real-life eyewitnesses
Improving the accuracy of eyewitness testimony: The cognitive interview
(Mental reinstatement of original context)
- One of the principal techniques of the cognitive interview where the interviewer encourages the interviewee to mentally recreate both the physical and psychological environment of the original incident
- The interviewer may say: ‘i would like you to think back to the day the event happened, the colours , how you felt etc’
- The aim is to make memories accessible
- People often cannot access memories that are there
- They need appropriate contextual and emotional cues to retrieve memories
Improving the accuracy of eyewitness testimony: The cognitive interview
(Report everything
- The interviewer encourages the reporting of every single detail of the event without editing anything out, even though it may seem irrelevant
- Witnesses should not leave anything out even if they believe it to be insignificant or irrelevant
- For example the interviewer might say: ‘I am interested in absolutely everything you remember, even if you think it might be unimportant please just tell me it all’
- Memories are interconnected with one another so that recollection of one item may then cue a whole lot of other memories
- In addition the recollection of small details may eventually be pieced together from many different witnesses to form a clearer picture of the event
Improving the accuracy of eyewitness testimony: The cognitive interview
(Change order)
- The interviewer may try alternative ways through the time-line of the incident, for example, by reversing the order in which the events occurred
- The rationale behind this is that our recollections are influenced by schemas
- For example, if you think about when you went to a restaurant a few weeks ago your recollection will be influenced by your general expectations (schema) of what is likely to happen at a restaurant- someone seats you at your tale, a waitress takes your order etc
- If you have to recall the events starting from the end of the event backwards this prevents your pre-existing schema influencing what you recall
- The interviewer might say:
Improving the accuracy of eyewitness testimony: The cognitive interview
(Change perspective)
- The interviewee is asked to recall the incident from multiple perspectives, for example by imagining how it would have appeared to other witnesses present at the time
- This is again done to disrupt the effect that schemas have on recall
- For example: Try to recall from the perspective of another person involved in the incident
- This approach was suggested by the research by Anderson and Pichert
Evaluation: Improving the accuracy of eyewitness testimony:
Research into the effectiveness of the cognitive interview
- A meta-analysis of 53 studies studies found, on average, an increase of 34% in the amount of correct information generated in the cognitive interview compared with standard interviewing techniques
- Although most of these studies involved volunteer witnesses (usually college students) tested in a lab (such studies may not reflect real-world practices)
- However, the effectiveness of the cognitives interview may be due more to some individual elements rather than the whole thing
- Milne and Bull interviewed undergraduate students and children using just one individual component of the cognitive interview and compared the responses gathered to a control condition (where they were instructed simply to ‘try again’)
- Recall across each of the four individual components was broadly similar and no different from that of the control group
- 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 in all other conditions
Improving the accuracy of eyewitness testimony: The cognitive interview
(Quantity versus quality)
- The procedure is designed to enhance the quantity of correct recall without compromising the quality of that information
- However, it may be that effectiveness has largely been in terms of quantity
- Kohnken found an 81% increase of correct information but also a 61% increase of incorrect information when the enhanced cognitive interview was compared to a standard interview
Improving the accuracy of eyewitness testimony: The cognitive interview
(Problems with using the cognitive interview in practice)
- From their interviews with police, Kebbell and Wagstaff report a problem with the cognitive interview in practice
- Police officers suggest that this technique requires more time than is often available and that instead they prefer to use deliberate strategies aimed to limit an eyewitness’ report to the minimum amount of information that the officers feel is necessary
- In addition, cognitive interview requires special training and many forces have not been able to provide more than a few hours
- For these reasons the use of the cognitive has not been widespread
Long term memory is divided into two main types:
- Explicit (or declarative) memory and implicit (or procedural)
- This is a distinction between knowing that and knowing how
Episodic memory:
- The term ‘episodic’ comes from the word ‘episode’- an event or a group of events occurring as part of a larger sequence
- This kind of memory is concerned with your personal experiences, with your recollection of your first day at school or a family holiday
- You may recall the time, place and who were there
- You may also recall associated emotions that you felt at the time
- 3 elements: specific details of the event, context and emotions
Semantic memory:
- Factual e.g. 2+2=4 or the capital of England is London
- Knowledge about the world which is shared rather than personal
- Functions of objects/ appropriate behaviour/social customs/abstract conecepts e.g. math/language
- Generally begin as episodic memories because we acquire knowledge based on personal experiences
- Memory slowly loses its associations to particular events so information can be generalised as a semantic memory
Procedural memory:
- Concerned with skills, such as knowing how to tie a shoelace or knowing how to read
- Remembering how to do something
- Typically required through repetition and practice
- We are less aware of these because they have become automatic
- Often, thinking too much about them stops you from acting them out
- This attention to the procedure can disrupt the automatic performance
- It is important that procedural memories are automatic so we can focus on other tasks while performing these everyday tasks
