memory Flashcards
what are the 3 types of memory stores?
- sensory
- short term memory
- long term memory
what is the sensory memory?
- sensory information is stored in the sensory memory just long enough to go into our short-term memory
- it is responsible for getting information from the 5 main senses to our brain
- it allows environmental info to be retained sometimes for as little as a fraction of a second as it goes into our consciousness
what is the coding, duration and capacity of the sensory memory?
coding- modality (specific), depends on the senses
duration- very brief, less than half a second
capacity- very high e.g. over one hundred million cells in one eye each storing data
what is short term memory and what is its coding, duration and capacity?
- short term memory is a limited capacity store of temporary duration
coding- acoustic
( based on sound )
duration- about 18 seconds unless the information is rehearsed
capacity- between 5 and 9
( 7 + - 2 ) items before some forgetting occurs
what is long term memory and what is its coding, duration and capacity?
- long term memory is the permanent memory store
coding- semantic ( in terms of meaning )
duration- potentially up to a lifetime
capacity- can hold memories for potentially up to a lifetime
what is meant by the term coding?
- how information is stored in various memory stores
- information enters the brain via senses and then changes to another form so it can be stored in your memory
- it can be stored in the form of sounds
( acoustic ), images ( visual ) and meaning
( semantic )
what is meant by the term capacity?
- the amount of information that can be held in the memory
what is meant by the term duration?
- the length of time that information can be held in our memory
who studied the coding of short term and long term memory?
- Baddeley ( 1966 ), he wanted to investigate if we code acoustically ( sound ) or semantically ( meaning )
what is coding?
- coding is the process of changing information into a format e.g. acoustic, semantic and visual
how did Baddeley carry out his study?
- 72 opportunity sampled participants were randomised into 4 different groups
( acoustically similar or dissimilar and semantically similar / dissimilar ) - each group then received a different 10-word list before being tested on their knowledge, this procedure was then repeated 4 times
what were the findings of his study?
- ppts had to recall the words in the correct order they were given
- short term memory
( STM ) recall was immediate, and it showed they did worse with acoustically similar words - long term memory
( LTM ) recall was after 20 minutes, and they did worse with semantically similar words
what were the positives to Baddeley’s study?
- later research showed that there are expectations to Baddeley’s findings, STM being mostly acoustic and LTM being mostly semantic
- this led to the development of the multi-store model
what were the negatives of Baddeley’s study?
- the words used had no personal meaning to the ppts so tells us little about coding for everyday memory tasks
- so when processing more meaningful information, people use semantic coding even for STM, this means the findings of this study have limited application
who studied the capacity of short-term memory using digit spans?
Jacobs ( 1887 ), he tested and measured digit spans
how did Jacob carry out his study and what were his findings?
- he read out a 4 digit code, which the ppts has to recall out loud or in writing in the same order
- if they got this correct, the researcher would go on to read out a 5-digit code and onward until the ppts are unable to recall the sequence
- he found that the mean span for digits across all ppts was 9.3 items, but the span for letters was only 7.3 and that the average capacity of STM is 7 items
what was the positives of Jacobs study?
P= one strength is that his study has been replicated
E= Jacobs study is very old and lacked adequate controls e.g. some ppts may have been distracted during testing which would mean that their digit spans were underestimated
E= despite this, Jacobs findings have been confirmed by other, better controlled studies since
L= this suggests that Jacob’s study is a valid test of digit span in STM
what are the limitations of Jacobs study?
P= one limitation is that Jacobs research lacks ecological validity
E= the task of recalling digits in a specific order may represent how we use STM in real-life situations, where the information we need to retain is often more complex and meaningful
E= this makes Jacob’s findings less generalisable to everyday memory processes
L= this suggests that the study is low in mundane realism and external validity
who studied the capacity of short-term memory using the ‘magic number 7’?
- Miller ( 1956 ), studied capacity of STM, using chunking
how did Miller carry out his study and what were his findings?
- miller observed everyday activities and found that everything comes in 7’s
- this then influenced his theory which was that the capacity of the STM is 7 items plus or minus 2 pieces of information and we remember through chunking since it improves our recall
what is meant by chunking?
- grouping sets of information into sections / chunks
what are the positives of millers study?
P- millers work emphasised the importance of chunking as a strategy to improve our active recall, by grouping information into larger, more meaningful units, individuals can effectively increase their memory capacity
E= this concept is applicable to academic contexts and in everyday life, such as remembering phone numbers, or shopping lists making it both accessible to researchers and the general public
E= therefore, millers STM study is positively evaluated for it’s contribution to psychology as well as it’s use of practical applications
what are the limitations of millers study?
P= one limitation is that miller overestimated short-term memory capacity
E= nelson Cowan ( 2001 ) reviewed other research and concluded that the capacity of short-term memory is only about 4
( plus or minus 1 ) chunks of information
E= this suggests that the lower end of Millers estimate of five items is more appropriated than seven items
who studied the duration of short term memory using consonant syllables?
- Peterson and Peterson
( 1959 ), studied STM with consonant syllables, his hypothesis was that information that isn’t rehearsed is lost quickly from the STM - IV = time intervals between ppt being given their consonant syllable and having to recite it
- DV = number of letters that were recalled correctly after every trial
what was Peterson and Petersons procedure?
- Margaret and Lloyd did a lab study to assess STM
- 24 psychology students were used in 8 trials each
- in each trial students were given a consonant syllable ( such as YCG ) to remember
- then they were given a 3 digit number and told to count backwards from this number until told to stop, this was in order to prevent any mental rehearsals
- on each trial, the ppts were told to stop counting at various time intervals e.g. some were told to stop after 3 seconds and some after 6 seconds
what were the findings of perterson and peterson study?
- the longer the students counted backwards, the less accurately they could recall the trigrams
- after 3 seconds 80% of the trigrams were recalled correctly
- after 6 seconds this then fell to 50%
- after 18 seconds less than 10% of the trigrams were recalled correctly
what are the strengths of this procedure?
- it is a lab experiment so there is lots of control over extraneous and confounding variables
- it follows a standardised procedure, meaning it can be repeated which increases the study’s reliability
what are the negatives of this procedure?
- we sometimes try to recall meaningless things so the study is not completely irrelevant , but the recall of consonant syllables does not reflect meaningful everyday memory tasks, therefore the study lacks external validity ( low mundane realism )
who studied the duration of long term memory using yearbook photos?
- Bahrick et al (1975 ), he aimed to study long term memory and how people remember certain types of information
- he predicted that people could remember information such as names and faces for almost a lifetime
how did Bahrick et al carry out his procedure?
- he used an opportunity sample of 392 high school graduates from America ranging from 17-74
- there was 2 conditions:
1) recognition test- 50 photos from high school yearbooks
2) free recall test- ppts listed names of their graduating class
what were the findings of Bahrick et als procedure?
recognition test- 90% accurate after 15 years, 70% after 48 years
free recall test- 60% recall after 15 years, 30% recall after 48 years
- these results show that free recall declined the most within 32 years although both methods showed lower accuracy over the years photo recognition remained high throughout
what were the positives of this study?
- everyday meaningful memories ( e.g. of peoples faces and names ) were studied, as when lab studies were done with meaningless pictures to be remembered, recall rates were lower
- this means that Bahrick et als findings reflect a more ‘real-life’ estimate of the duration of LTM
what were the negatives of this study?
P- lacks generalisability
E- bahrick only investigated how well people remembered names and faces of people from an American graduated school
- this doesn’t explain long term memory for other types of information e.g. directions, so findings cannot be generalised to other places of age groups
what is the multi-store model?
- a basic idea of how the memory system operates and the various parts that it contains
- it is not an exact copy but a representation of how something works
- helps us to understand how parts of the model work together
what is the purpose of the multi-store model?
- helps us to make predictions about behaviour and helps generates hypothesis
- as understanding progresses, we can reject one model for another or modify it to new findings
- the two models are the multi-store model and the working model of memory
- the model suggests that memory is made of 3 seperate stores that is linked by processing: LTM, STM and sensory
- this is the most influential model of memory
what are the 3 stages of the multi-store model?
- sensory register
- short term memory
- long term memory
what is the sensory register?
- all stimuli from the environment ( e.g. the sound of someone talking ) pass into the SR, this part of memory is not one store but five, one for each sense
- the 2 main stores are iconic and echoic memory
what is the iconic and echoic memory?
iconic- stored as images ( sight )
echoic- stored as sound ( hearing )
how do you transfer from SR to STM?
- information passes further into memory only if attention is paid to it ( attention is the key to stm )
how do you transfer from STM to LTM?
- maintenance rehearsal occurs when we repeat ( rehearse ) material to ourselves
- we keep information in STM as long as we rehearse it
- if we rehearse it long enough, it passes into LTM
how do we retrieve from our LTM?
- when we want to recall information stored in LTM it has to be transferred back to STM by a process called retrieval
what are the strengths of the multi-store model?
P- the model supports every piece of research we’ve looked at based on LTM and STM
E- this is because it shows there is functional separation between STM and LTM stores
E- Baddeley found that we tend to mix up words that sound similar when using our STMs, but we mix up words that have similar meanings when we use our LTMs, this supports the multi-store models views that these two memory stores are seperate and independent
counterpoint- despite such apparent support, the studies tend not to use everyday information, and instead use digits / letters ( jacobs ) or consonant syllables ( peterson and peterson ), therefore the MSM may not be a valid of how memory works in everyday life where memory tends to involve meaningful information
what is another strength of the MSM?
P- individuals with memory disorders have provided evidence relating to MSM
E- HM underwent brain surgery to relieve his epilepsy, crucially a part of his memory ( hippocampus ) was removed so when assessed in 1955 he thought it was 1953 and that he was 27
( he was 31 )
- however, he performed well on tests of immediate memory span
( measure of STM ), but he could not form LT memories
E- this supports that there are 2 seperate and independent memory stores ( LTM and STM ), so one can be damaged and not effect the other
what’s a limitation of the MSM?
P- the MSM states that STM is a unitary store and that there is only one type of STM
E- however, evidence from those suffering with amnesia shows this cannot be true
E- Shallice and Warrington studied a ppt with amnesia known as KF, his recall for digits was poor when read out loud, but better when he read them showing there is a possibility for another STM store for non-verbal sounds
L- unitary STM is a limitation as research shows there should be at least one store
what was Tulving’s correlation to 1985?
- he was the first cognitive psychologist to realise that MSM’s view of LTM was far too simplistic and inflexible
- Tulving proposed that there are 3 LTM stores, all which can contain different types of information
what are the 3 types of LTM?
1) episodic memory
2) semantic memory
3) procedural memory
what is episodic memory?
- refers to our ability to recall events ( episodes ) from our lives
- this has been likened to a diary as it is like a record of daily occurrences
e.g. what you had for breakfast this morning, a date etc. - in simpler worlds ( personal collections )
what does the episodic memory in tale?
- firstly, they are ‘time-stamped’ so you remember how they happened and how they relate in time
- secondly, your memory of a single episode will include several elements such as people, places, objects, behaviours etc
- thirdly, you have to make a conscious effort to recall episodic memories, you may be able to do so quickly, but you are still aware that you are searching your memory of that event
what is semantic memory?
- this store contains our knowledge of the world, this included facts
- this type of memory has been likened to a combination of an encyclopaedia and a dictionary
- in simpler words ( general knowledge )
what does the semantic memory in tale?
- these memories are not time-stamped as we don’t usually remember the first time we learnt about specific things
- semantic knowledge is less personal and more about facts we all share
- it contains an immense collection of material which, given it’s nature, is constantly being added to
what is a procedural memory?
- this is our memory for actions, skills and how we do things
- we can recall these memories without conscious awareness or a great deal of effort e.g. riding a bike
- our ability to do this ( eventually ) depends on procedural memory
- these are skills that we do without conscious recall and sometimes find hard to explain to someone else
what is a positive evaluation of Tulving’s ideas of different types of LTM?
P- the famous case studies of HM and Clive Wearing are relevant in supporting different types of LTM
E- Episodic memory in both men was severally impaired as a consequence of amnesia, they both had great difficulty in recalling events that had happened to them in their past and there semantic memories were also relatively unaffected
E- for example, they still understood the meaning of words as HM would not be able to recall stroking a dog 30 minutes ago and could not remember having owned a dog in the past, but he would not need the concept of a dog explained to him
- their procedural memories were also intact as they were able to walk, speak and tie laces
L- therefore, this supports Tulving’s proposition of different long-term memory stores as one store could be damaged and the other would remain intact
what is a counterpoint to this positive?
- researchers lack control in clinical case studies- they do not know anything about the person’s memory before brain damage
- therefore, clinical studies are limited in what they can tell us about different types of LTM
what is a limitation to Tulving’s ideas of different types of LTM?
P- there is evidence from brain scan studies that different types of memory are stored in different parts of the brain
E- for example, Tulving et al 1994 got their ppts to perform various memory tasks while their brains were scanned using a PET scanner
E- they found that episodic and semantic memories were both recalled from an area of the brain known as the prefrontal cortex, this area is divided into 2, one each side of the brain
- the left prefrontal cortex was involved in recalling semantic and episodic memories were recalled from the right prefrontal cortex
L- this therefore supports the view that there is a physical reality to the different types of LTM within the brain, this research has been confirmed many times in later research studies supporting the validity of the findings
what is the working memory model?
- the working memory model is an explanation of how one aspect of memory ( STM ) is organised and how it functions
- the WMM is concerned with the mental space that is active when we are temporarily storing and manipulating information e.g. working an arithmetic problem
- the model consists of 4 main components, each qualitatively different in coding and capacity
what are the main components of the WMM?
1) central executive
2) phonological loop
3) visuo-spatial sketchpad
4) episodic buffer
what is the role of the central executive?
- it monitors incoming data, directs attention and allocates subsystems to tasks
- it has a very limited storage capacity
what is the capacity and coding of the central executive?
capacity- limited capacity
coding- modality free ( does not store info )
what is the role of the phonological loop?
- the phonological loop deals with auditory information and preserves the order in which the information arrives
- it is subdivided into:
1) phonological store- stores the words you hear
2) articulatory process- allows maintenance rehearsal ( repeating sounds to keep them in WM while they are needed )
what is the capacity and coding of the phonological loop?
capacity- 2 seconds
coding- acoustic
what is the role of the visuo-spatial sketchpad?
- stores visual and/or spatial information when required, e.g. recalling how many windows your house has )
- Logie ( 1995 ) subdivided the VSS into:
1) visual cache: stores visual data
2) inner scribe- records arrangement of objects in visual field
what is the capacity and coding of the visuo-spatial sketchpad?
capacity- 3-4 objects
coding- visual
what is the main role of the episodic buffer?
- it is a temporary store for information, integrating the visual, spatial and verbal information processed by other stores and maintaining a sense of time sequencing
- it can be seen as a storage component of the central executive and it links working memory to LTM
what is the capacity and coding of the episodic buffer?
capacity- 4 chunks
coding- modality free ( doesn’t store info )
what is a positive evaluation of the WMM?
P- one strength is that the dual-task performance studies support the seperate existence of the visuo-spatial sketchpad
E- For example, Baddeley et al’s participants found it harder to carry out two visual tasks at the same time than do a verbal and a visual task together. This is because both visual tasks compete for the same subsystems ( VSS ) so there is no competition with a verbal and visual task
E- Therefore, there must be a seperate subsystem that processes visual input and also a seperate system for verbal processes ( PL )
what is another strength of the WMM?
P- Another strength of the WMM is that we have supportive evidence from the case study of patient KF
E- For example, KF, who suffered from amnesia, would perform well on visual memory tasks but not on auditory tasks when digits / letters were read to him
E- This suggests that there are 2 seperate stores for visual and acoustic memory as KF’s phonological loop for auditory information was damaged by his visuo-spatial sketchpad was not
what is a negative evaluation of the WMM?
P- One limitation is that there is a lack of clarity over the nature of the central executive
E- Baddeley recognised that the CE was the most important but the least understood component of the working memory, this means there must be more to the CE than just being ‘attention’ e.g. it is made up of seperate subcomponents
E- therefore, the CE is an unsatisfactory component and this challenges the integrity of the model
what is meant by interference?
- interference is a process that affects memory recall in which specific memories interfere with the retrieval of other memories
- interference occurs when we can’t access the target memory because other similar memories make it difficult to do so
- interference is proposed as an explanation for forgetting in the LTM
what is forgetting in terms of interference?
- this occurs when 2 pieces of information disrupt each other resulting in forgetting of one or both
what are the 2 types of interference?
- proactive
- retroactive
what is meant by proactive interference?
- when an older memory interferes with a newer one e.g. being used to a manual car and then trying to change gears in an automatic or if you keep using the controls on an iPhone after switching to a Samsung
what is meant by retroactive interference?
- this is when a newer memory interferes with an older one e.g. forgetting an old password after changing to a new one or starting a new topic and trying to remember something from the old one
who studied the research on effects of similarity?
- in 1931McGeoch and McDonald predicted that proactive interference and retroactive interference is worse when the memories or learning are similar
what procedure did they carry out?
- they studied retroactive interference by changing the amount of similarity between 2 sets of materials ( original word list and the 2nd word list ), ppts has to learn a list of 10 words until they could remember them with 100% accuracy in which they then had to learn a new list
- there were 6 groups of ppts who had to learn different types of new lists
what were the 6 groups?
group 1- synonyms- words with the same meanings as the originals
group 2- antonyms- words with the opposite meanings to the originals
group 3- words unrelated to the original ones
group 4- consonant syllables
group 5- three digit numbers
group 6- no new list- these ppts just rested ( control condition )
what were the findings and conclusions of the study?
- when the ppts were asked to recall the original list of words, the ppts who has the most similar words on their 2nd list performed the worst
- this shows that interference is strongest when the memories are similar
what are the reasons for the effects of similarity?
- it could be due to proactive interference- previously stored information makes new information more difficult to store
- or it could be due to retroactive interference, new information overwrite previous similar memories because of the similarity
what is a positive evaluation interference theory?
P- a strength of interference as a reason for forgetting is backed by supporting evidence
E- For example, McDonald and McGeoch studied retroactive interference by changing the amount of similarity between 2 sets of materials ( original list of words and the 2nd word list )
- they found that all ppts who learnt a new list experience interference, with the ppts who had the most similar words on their second word list ( synonyms ) performing the worst recall
E- This suggests that there must be some validity to the theory of interference
what is another strength of interference theory?
P-Baddeley and Hitch ( 1977 ) asked rugby players to remember who they had played against
E- they found that the amount of time that has gone by was not important in accuracy of memory, but how many games they’d played was important
- played who had played the most games has the poorest recall of the teams they had played against
E- this shows that interference can operate in at least some real world applications, increasing the validity of the theory
what is a counterpoint to this strength?
- interference in everyday situations is unusual because the necessary conditions are relatively rare e.g. similarity of memories / learning does not occur often
- therefore, most everyday forgetting may be better explained by other theories ( e.g. retrieval failure due to lack of cues )
what is a limitation of interference theory?
P- the stimulus materials used in studies of interference involve learning lists or words or trigrams
E- this is artificial as it is far from the things we learn and try to remember in real life
E- this is a weakness of interference theory as the use of artificial tasks make interference much more likely in the lab, so it may not be a likely explanation for forgetting in everyday life
- therefore interference theory lacks ecological validity
what is another limitation of interference theory?
- an issue with interference theory is that, while interference effects do occur in everyday life, they don’t occur that often
- the problem is that it only really explains forgetting when two sets of information are similar, such as learning French and German at school
- another issue is that even similar information does not always conflict
- interference theory would predict that learning several languages should be impossible due to the confusion it would cause and yet many people are multi-lingual
how is forgetting explained through retrieval failure?
- the reason one forgets information is because of insufficient cues
- when information is initially placed in our memory, associated cues ( triggers of information recollection ) are stored at the same time
- if these cues are not available at the time of recall, you may appear to of forgotten the information, but it is due to retrieval failure ( not being able to access memories that are there )
what is the encoding specificity principle?
- Tulving reviewed research into retrieval failure and discovered a consistent pattern to the findings known as the encoding specificity principle
- this states that a cue has to be both 1) present at encoding- when we learn the material and 2) present at retrieval- when we recall the material
- if the cues available at encoding and retrieval are different or if cues are entirely absent there will be some forgetting
what are the 2 types of non-meaningful cues?
1) context-dependent forgetting- recalled depends on external cues e.g. weather or place
2) state-dependent forgetting- recall depends on an internal cue e.g. upset or drunk
what supporting research was done to provide evident for context-dependent forgetting?
- Godden and Baddeley ( 1975 ) where they studied deep-sea divers who worked underwater to see if training on land helped or hindered their work underwater
- they had to learn word lists and then later had to recall them
what were the 4 conditions for this experiment and what were the findings?
1) learn on land- recall on land
2) learn on land- recall underwater
3) learn underwater- recall on land
4) learn underwater- recall underwater
- they found that accurate recall was 40% lower in conditions 2 and 3 ( mismatched contexts ) than in conditions 1 and 4 ( matched contexts )
- retrieval failure wad due to absence of encoded context cues at time of recall- material was not accessible e.g. forgotten
what supporting research was done to provide evident for state-dependent forgetting?
- Carter and Cassaday ( 1998 ) where they gave antihistamine drugs ( for hay fever ) to their ppts, the drug has a mild sedative effect making the ppts slightly drowsy
- this creates an internal physiological state different from the normal state of being awake and alert
- ppts had to learn a list of words in either normal physiological state of non-normal state and recall again in either physiological state
what were the 4 conditions and the findings of the study?
1) learn on drug- recall when on drug
2) learn on drug- recall when not on drug
3) learn not on drug- recall when on drug
4) learn not on drug- recall when not on drug
- recall was significantly worse in conditions 2 and 3 ( mismatches cues ) compared with conditions 1 and 4 ( matched cues )
- so when the cues are absent there is more forgetting
what is a positive evaluation of retrieval cues?
P- one strength is that there is supporting research for retrieval cues
E- for example, Godden and Baddeley, tested divers in different conditions and Carter and Cassaday, who tested ppts with and without drugs, show that lacks of cues at recall leaded to everyday forgetting
E- this evidence shows that retrieval failure due to lack of cues occurs in everyday life as well as in highly controlled labs
counterpoint- Baddeley argues that different contexts have to be very different indeed before an effect is seen ( e.g. on land vs underwater )
- learning something in one room and recalling it in another is unlikely to result in much forgetting because the environments are not different enough. this means that retrieval failure due to lack of contextual cues may not explain much everyday forgetting
what is another strength of retrieval cues?
P- one strength is that retrieval cues have real-life application
E- ‘reinstate context’ element of the cognitive interview
E- this shows how this research can help to improve our memory in the real world, with important impact e.g. reduced miscarriage of justice
what is a negative evaluation of retrieval cues?
P- one limitation is that encoding specificity principle cannot be tested
E- it is impossible to know whether a cue has been encoded by a ppt, we can only make assumptions
E- this means that the ESP is not scientifically testable, undermining the validity of the theory, as we cannot be certain that forgetting id due to retrieval cues
what is another negative of retrieval cues?
P- one limitation is that context-dependent forgetting effects vary in recall and recognition
E- Godden and Baddeley ( 1980 ) replicated their underwater experiment using a recognition test instead of recall
- there was no context-dependent effect and the findings were the same in all 4 conditions, whether the contexts for learning and recall were matched or not
E- this suggests that retrieval failure is a limited explanation for forgetting because it only applies when a person has to recall information rather than recognise it
what is an eyewitness testimony?
- the ability of people to remember the details of events such as accidents and crimes, which they themselves have observed
what is a leading question?
- the wording of a question which may lead someone to give a certain answer
- this is particular in police questions to an eyewitness
who carried out the study regarding leading questions and what was the procedure?
- Loftus and Palmer ( 1974 ) got 45 ppts to watch film clips of car accidents and then got them to answer questions about speed
( ‘how fast were the cars going when they hit each other?’ ) - there was 5 groups of ppts, who were each given a different verb in the critical question: hit, bumped, contacted, collided, smashed
what were the findings of the study?
- the verb ‘contacted’ produced a mean estimated speed of 31.8mph
- the verb ‘smashed’ produced a mean estimated speed of 40.5mph
- the use of the verb ‘smashed’ led the ppts to believe that the cars must have been travelling at a reasonably high speed. this leading question may have altered their memories so that they genuinely believed the cars were travelling faster, so they estimated a higher speed
why do leading questions affect eye witness testimony?
1) response bias explanation- suggests that the wording of the question has no real effect on the ppts memories but just influences how they decide to answer
2) substitution explanation- suggests the wording of a leading question can actually change ppts memory of an event
what study was carried out to
support the substitution explanation?
- Loftus and Palmer conducted a second study asking ppts with the verb ‘smashed’ and ‘hit’ if they had reported seeing broken glass
( there was none ) - ‘smashed’ were more likely to report yes, meaning leading questions can alter memory
what is meant by post event discussion?
- this is when eyewitnesses to a crime may discuss their experiences with each other which may have a negative effect
what study supports post event discussion and what was the procedure?
- Gabbert et al ( 2003 ) paired ppts and made them watch a video of the same crime, but filmed so each ppt could see elements in the event that the other could not
- both ppts discussed what they had seen in the video before individually completing a test of recall
what were the findings of the study?
findings- 71% of ppts wrongly recalled aspects of the event they did not see in the video but had heard in the discussion
control group- there was no discussion and no subsequent errors
- this was evident of memory conformity
why does post event discussion affect eye witness testimony?
1) memory contamination- is when co witnesses discuss a crime which causes their memory to become altered or distorted, this is because they combine
( mis ) information with their own memories
2) memory conformity- is where co witnesses go along with each other to win social approach or because they believe other witnesses are right, memory isn’t changed just added to
what are the strengths of leading questions?
P- research on leading questions real world applications to criminal justice systems
E- the consequences of inaccurate EWT are serious. Loftus (1975) argues police officers should be careful in phrasing questions to witnesses because of distorting effects. psychologist are sometimes expert witnesses in trials and explain limits of EWT to juries
E- therefore, psychologists can improve how the legal system works and protect the innocent from faulty convictions based on unreliable EWT
what is a counterpoint to this strength?
- Loftus and Palmer showed film clips- a different experience from a real event ( less stress )
- ppts are also less concerned about the effect of their responses in a lab study
- therefore, researchers may be to pessimistic about the effects of misleading information- EWT may be more reliable than studies suggest
what is another strength of leading questions?
P- memory conformity does change / distort one’s original memory
E- ppts discussed film clips they had seen ( in one version the mugger had dark brown hair and the other light brown )
- the ppts recalled a ‘blend’ of what they had seen and what they had heard from their co-witness, rather than one or the other ( e.g. said hair was medium brown )
E- this suggests that the memory itself is distorted through contamination by post-event discussion and is not the result of memory conformity
what is another strength and a limitation of leading questions?
strength- the studies on misleading information are in lab environments which means variables have been controlled and increases internal validity, so they can demonstrate that misleading post-event information causes inaccurate EWT
limitations- but ab experiments suffer from demand characteristics- ppts want to help so they guess when they can’t answer a question ( low external validity )
- therefore to maximise internal validity, researchers should reduce demand characteristics by removing the cues that ppts use to work out the hypothesis
how does anxiety create a negative effect on recall?
- anxiety creates psychological arousal in the body which prevents us from paying attention to important cues so recall is worse
what is meant by weapon focus?
- this is when anxiety levels increase due to the ppts focus being on the weapon, meaning the recall is worse as other details are not noticed
who conducted the study on weapon focus and what was the procedure?
- Johnson and Scott ( 1976 ) deceived ppts into thinking they were doing a lab study by sitting in a waiting room
- there was 2 conditions:
1) low anxiety levels- ppts heard a casual conversation and then saw a man walk through the waiting room carrying a pen with grease on his hands
2) high anxiety levels- a heated argument was accompanied by the sound of breaking glass and a man walked through the room holding a knife covered in blood ( creating anxiety due to weapon focus ) - ppts were then later asked to pick the man from a set of 50 photographs
what were the findings and conclusions of the study?
findings- 49% of ppts in the low anxiety condition and 33% of high-anxiety ppts were able to identify the man
conclusions- the tunnel theory of memory argues that people have enhanced memory for central events
- weapon focus as a result of anxiety can have this effect
who studied the positive effects of anxiety and what was the procedure?
- Yuille and Cutshall ( 1986 ) conducted a study on an actually shooting in a shop where the shop owner shot a thief dead
- there were 21 witnesses with 13 taking part
- they were interviewed 5 months after the incident and the information recalled was compared to the police interviews at the time of the shooting
- witnesses rated how stressed they felt at the time of the incident
what were the findings and conclusions of the study?
findings- witnesses were very accurate in what they recalled and there was little change after 5 months, some details were less accurate e.g. age, weight, height etc
conclusions- ppts who reported the highest levels of stress were most accurate ( about 88% compared to 75% for the less-stressed group )
- anxiety does not appear to reduce the accuracy of EWT for a real-world event and may even enhance it
who conducted a met analysis study and what is the Yerkes Dodson Law?
- Yerkes and Dodson state the relationship between emotional arousal and performed looks like an inverted U
- Yerkes Dodson Law is when we witness a crime we become emotionally and physiologically aroused
- therefore low levels of arousal produce low levels of recall and our memory becomes more accurate as the arousal increases
- however, there is an optimal level e.g. too much arousal also causes decline in recall
what is one problem with inverted U theory?
P- the inverted U theory appears to be a reasonable explanation of the contradictory findings linking anxiety with both increased and decreased eyewitness recall
E- however it only focuses on physical anxiety and ignores other elements including cognitive ( how we think about a stressful event affects what we recall )
E- therefore, the inverted U theory explanation is probably too simplistic to be useful e.g. anxious thoughts may not always lead to symptoms of anxiety but may block memory
what is a limitation of negative effects?
P- one limitation of Johnson and Scott is that it may not have been tested for anxiety so may not be relevant to weapon focus
E- Pickel ( 1998 ) found that accuracy in identifying the ‘criminal’ was poorest when the object in their hand was unexpected e.g. raw chicken and a gun in a hairdressers ( both unusual )
E- this suggests the weapons effect is due to unusualness rather than anxiety / threat and so tells us nothing about the specific effects of anxiety on recall
what is a strength of negative effects?
P- Valentine and Mesout ( 2009 ) used heart rate to divide visitors to London Dungeon Labyrinths into low and high anxiety groups
E- high anxiety ppts were less accurate than low anxiety in describing and identifying a target person
E- this supports the claim that anxiety has a negative effect on immediate eyewitness recall of stressful events
what is another strength on negative effects?
P- one stength is that there is supporting research
E- Christianson and Hubinette
(1993) interviewed actual witnesses to bank robberies- some were direct victim ( high anxiety ) and others were bystanders ( less anxiety )
- they found more accurate recall across all witnesses and direct witnesses ( most anxious ) were event more accurate
E- this suggests that anxiety does not affect the accuracy of eyewitness recall and may even enhance it
counterpoint- the researchers interviewed witnesses long after the event so many things happened that the researchers could not control ( e.g. post event discussion ), therefore there is a lack of control over confounding variable which may lead to inaccuracy of recall and not anxiety
what is a cognitive interview?
- Fisher and Geiselman ( 1992 ) claimed that eye witness testimony could be improved if the police use techniques based on psychological insights into how memory works
- they called it the cognitive interview to indicate it’s foundation in cognitive psychology
what are the 4 main techniques when carrying out a cognitive interview?
1) report- witnesses are encouraged to include every detail of an event, even if it seems irrelevant or the witness is not confident about it. seemingly trivial details could be important and may trigger other memories
2) reinstate the context- the witness returns to the original crime scene ‘in their mind’ and imagines the environment and their emotions. this is done as cues from the context may trigger recall
3) reverse order- events are recalled in a different order e.g. from the end back to the beginning or from the middle to the beginning. this prevents people basing their descriptions on their expectations of how the vent must have happened rather than the actual events. it also prevents dishonesty as it is harder to produce an untruthful account if it has been reversed
4) change perspective- witnesses recall the incident from other peoples perspectives ( how it could appear to other witnesses ), this prevents the influence of expectations and schema on recall as the schema you have for a particular expectations generates expectations of what would have happened vs what actually happened
what is an enhanced cognitive interview?
- Fisher et al ( 1987 ) developed additional elements of the CI
- this includes a focus on the social dynamics of the interaction ( e.g. knowing when to establish eye contact and relinquish it )
- the enhanced CI also includes ideas such as reducing the EWT’s anxiety, minimising distractions, getting the witness to speak slowly and asking open-ended questions
what is a positive evaluation of cognitive interviews?
P- one strength is that there is research to support the effectiveness of the CI
E- a meta-analysis combined data from 55 studies comparing CI and ECI with the standard police interview and the CI produced an average of 41% more correct information than the standard interview, with only 4 studies showing no difference
E- this shows that the CI is effective in helping witnesses recall information that is available but not accessible
what is a negative evaluation of the cognitive interview?
P- one limitation is that not all elements of the cognitive interview are equally effective or useful
E- Milne and Bull ( 2002 ) found that combining ‘report everything’ and ‘reinstate the context’ produced better recall than any other technique individually or combined
E- this casts doubt on the credibility of the overall CI because some of the techniques are less effective than the others
what is another negative evaluation of the CI?
P- police are reluctant to use the CI because it takes more time than the standard police interview ( e.g. to establish rapport and allow the witness to relax )
E- the CI also requires special training but many forces do not have the resources to provide more than a few hours training
E- this suggests that the complete CI is not realistic for police officers to use and it might be better to focus on just a few key elements instead of all
