Three memory stores:Sensory memory
Sperling’s experiment:
Flashed several rows of letters on a screen for a split second to participants to see how many they could read-usually only 3 or 4 letters
Then he added a high, medium or low tone after he showed the letters to indicate which row to recall-he found as long as it was sounded 250 milliseconds after the flash participants could recall 3 out of 4 letters from any row.Apparently they preserved a memory of the entire image for a quarter of a second.
capacity- Sperling’s experiment suggested limitless capacity
duration-less than a second
coding-stored in the raw form
Three memory stores:short term memory- Baddeley’s study
objective-to test whether STM is coded acoustically or semantically
4 words lists-a (acoustically similar), b (acoustically dissimilar), c (similar meanings) and d (distinctive meanings)
-read list a in a monotone voice then cover and try to recall immediately.Must be written in correct sequence to count.Repeat for all lists.Multiply the correct number of words from each list by 10 to get a percentage.
He reported percentages of correctly recalled word lists were 10% for a, 82% for b, 65% for c, and 71% for d
we can conclude STM is coded acoustically because acoustic confusion occurred in his experiment.
Baddeley’s study of STM :EVALUATION
strengths:
-internal validity (we can establish cause and effect).High because all extraneous variables were controlled so we can say for certain that the sound impacted memory compared to the meaning.
-reliable
Limitations:
-low mundane realism.The tasks (learning word lists) is not reflective of everyday STM tasks.Everyday tasks are often meaningful and linked to other memories (e.g conversations, why you walked into a room)
-STM might not be exclusively acoustic.some experiments have shown that visual codes are also used in STM.For example Brown et al. found that participants used visual coding if they were given a visual task and prevented from doing any verbal rehearsal.
Three memory stores:short term memory-Jacobs
experimenter
reads out a 4 digit number in a monotone voice and gradually increases the length of the number sequences until you have a number sequence of 15.Sequence is written down immediately after every time.When they no longer consistently recall the number correctly make note of the number of digits they could recall, this is a measure of their STM
-Jacobs found an average of 9.3 for numbers and 7.3 for letters
-Miller claimed people have an STM of between 5 and 9 items
Evaluation:
-individual difference affect STM-Jacobs found that 8 year olds could remember an average of 6.6 digits whereas 19 year olds could remember an average of 8.6.Therefore most conclusions are too simple.
-Chunking can improve STM (e.g remembering them as dates) however research as to how many chunks can be remembered is contradictory as the size of the chunks seem to affect capacity.Much more research needs to be done regarding this as our current knowledge of the true capacity of STM seems to be limited.
Three memory stores:short term memory-Peterson & Peterson
aim-investigate the duration of STM
-laboratory experiment
-24 students, 8 trails.On each trail they were given a constant trigram and a number trigram e.g GKL 876.Asked to recall the constant trigram after 3, 6, 9, 12, 15 and 18 seconds.During the retention interval they had to count backwards from the numbers they were given
findings-80% correct at 3 seconds, 20% correct at 9 seconds, 2% correct at 18 seconds.STM duration is less than 18 seconds if verbal rehearsal is prevented.
Evaluation:
-lacked mundane realism (how realistic it is to everyday life) so might not reflect memory in everyday life
-Counting the numbers may have displaced the letters out of memory
-when an auditory retention task has been given STM is considerably longer
Three memory stores:long term memory-Baddeley
Baddeley- encoding in STM
method:laboratory experiment (continuation of the STM experiment).Sample of 72 in total, both men and women from the Cambridge uni subject panel (mostly students) they were volunteers.
procedure:part 2 of the STM encoding experiment.after the participants recalled the words list (acoustically similar/dissimilar or semantically similar/dissimilar) they carried out an interference task that involved hearing and writing down 8 numbers 3 times.They then had to recall the words from the slide show in order after 20 minutes.
findings:LTM is not confused by acoustic similarities as no forgetting occurred however semantically similar words were recalled not as well-semantic confusion occurred indicating that information is encoded semantically in LTM.
Evaluation:
A strength is high internal validity-extraneous variables were controlled so coding in Long term memory can be said with certainty to be semantic (cause and effect is established)
a limitation is low mundane realism-recalling word lists is not a typical everyday task so results may often not reflect real life.In real life we are often multitasking, distracted and information is rich in meaning
another limitation is it’s not representative of a whole population as there were only 72 and from Cambridge (might have better memory/higher IQ)
Three memory stores:long term memory- Bahrick and capacity
capacity of LTM-unlimited, information may be lost due to decay or interference, capacity can never be measure so there are no studies to test it.
Bahrick- duration
aim:to investigate duration of LTM
procedure:tested 400 people of various ages (17-74) of their memory of their classmates using a photo-recognition task.A free recall task was also given.
Findings:participants tested within 15 years of graduating were about 90% accurate in the recognition task.tThis declined to about 70% after 48 years.
Free recall was about 60% accurate after 15 years, dropping down to 30% after 48 years.
Conclusion:
-duration of LTM is possibly a lifetime
However accessibility becomes more difficult and cues might be required
evaluation:
strength-one of the only memory studies to investigate real life memories, therefore results better reflect real life findings.Higher mundane realism or ecological validity
limitation- However ,this means extraneous variables were less controlled and the results could have been confused e.g how often participants met up with their classmates over the years or whether they even knew their names initially.
The multi-store model of memory-Atkinson & Shiffren
see diagram
Atkinson & Shiffren proposed three stores: a sensory register, short-term memory and long term memory
sensory-constantly receiving information but most of this receives no attention and remains in the sensory register for a very brief period.Information arrives from the 5 senses, large capacity but brief duration.Most information is lost via decay.
If a person’s ATTENTION is focused on one of the sensory stores this data is transferred to short term memory.
STM store has a duration of up to 30 seconds, capacity of 7+/-2 chunks, mainly encodes information acoustically.
Maintenance rehearsal (the process of verbally or mentally repeating information) allows short-term memory to extend beyond 30 seconds.E.g remembering a phone number only long enough to make the call.This type of rehearsal usually involves repeating information without thinking about it’s meaning or connecting it to other information.
Continual rehearsal renews the information in the memory trace thus, making it a stronger memory when transferred to the long term store.However if maintenance rehearsal does not occur, then information is forgotten, and lost from short term memory through the processes of displacement or decay
LTM has unlimited capacity and duration and encodes information semantically, information can be recalled from LTM to STM when it’s needed
Evaluation of the multi-store model of memory from Murdock
Murdock-the serial position curve
This provides supporting evidence for the key feature of the MSM that STM and LTM can be viewed as two separate and distinct systems.
5 word lists each read through once then after covered up and participants are asked to recall as many as possible, the number of words correctly recalled from each list is added up and put into a graph, the graph tends to have a U shape
primacy effect-explains the observation that the words at the beginning of a list tend to be recalled well ,suggesting that participants could rehearse them and transfer to LTM
recency effect-explains the observation that the last few words in the list tend to be recalled well as they are within the duration and capacity of STM, they are recalled immediately and not replaced.
words in the middle are remembered the least well as they couldn’t be rehearsed and transferred to LTM die to the participants being overwhelmed with information, and words later in the list displaced them from STM
supports MSM-concept of rehearsal is necessary to transfer information to LTM, and of displacement in STM.It also supports the proposal that there are separate STM and LTM stores.
Evaluation of the multi-store model of memory from K.F and Clive Wearing
K.F
-memory was impaired as a result of a motorbike accident
Support-he had a reduced STM (capacity of 1-2 digits), yet his LTM was normal.Supports as it suggests that STM and LTM are separate stores in different brain regions.
Challenging-the deficits in STM were only for verbal information; his STM for visual and acoustic material was normal suggesting there might be sub-stores in STM .Furthermore if his STM was damaged, the MSM suggests LTM should be too as memories pass through STM to be stored in LTM, as his LTM was normal this opposes the linear nature of the model
Clive Wearing
-got viral encephalitis which destroyed his hippocampi, which is the gateway to the LTM.Therefore ,his LTM is almost entirely destroyed
supports that STM and LTM are separate stores in the brain as STM is intact but LTM is affected
opposes because the case suggests that there are sub-stores in LTM as his procedural memories e.g how to walk (muscle movement) and his memories automatic were not damaged as he could still play piano.However his semantic memories were destroyed and he can’t form any new semantic, autobiographical and episodic memories.
The Working Memory Model- Baddeley and Hitch
see diagram
they argue MSM is too simple as it’s a unitary system.Whereas WMM is a multi-component system.Therefore whereas short-term memory in MSM can only hold information, MSM can both retain and process information
central executive-allocates data to subsystems (phonological loop and visuospatial sketchpad) and it deals with cognitive tasks such as mental arithmetic and problem-solving.Capacity is limited attentional and no ability to store, it’s modality free (can deal with any types of information)
visuospatial sketchpad-stores and processes information in a visual or spatial form, used for navigation.The capacity is 3-4 objects so it’s limited.Logie sub-divided the store into a visual cache (stores visual information, e.g form and colour) and the inner scribe (information about spatial relationships)
phonological loop-spoken and written material, sub-divided into the phonological store (holds information in a speech-based form, inner ear, processes speech perception and stores spoken words we hear for 2 seconds) and the articulatory process (allows us to repeat verbal information in a loop and process speech production, inner voice)
episodic buffer-modality free (can handle any information).A general store added later, central executive has no storage capacity, so it sends information to the EB which has a storage capability of about 4 chunks of information, it integrates information from all 3 stores (CE, PL, VSS).Also time keeps and sends information to LTM.
Evaluation of the Working Memory Model
strengths:
Dual task performance- Baddeley and Hitch found evidence for the existence of the central executive during dual task performance studies.Task 1 occupied the central executive while task 2 either involved only the phonological loop or both the phonological loop and the central executive.Task 1 was slower when task 2 involved both.This demonstrates the dual task performance effect and shows that the central executive is one of the components of working memory.
supporting evidence from case studies-Studies of individuals with brain damage also support the WMM.KF suffered brain damage from a motorcycle accident which damaged his short-term memory.His impairment was mainly for verbal information-his memory for visual information was largely unaffected.His auditory problems were limited to information such as verbal letters and digits but not meaningful sounds such as the phone ringing.This supports the theory that there are separate STM components for visual information and verbal information.
Limitations:
word length effect-A strength pf the WMM lies in the phonological loop and word length effect. An experiment by Baddeley et al. found that the phonological loop holds the amount of information that you can say in 2 seconds.This makes it harder to remember a long list of words compared to a short one.Longer words can’t be rehearsed in the phonological loop as they don’t fit.However the word length effect disappears if the person is given an auditory suppression task e.g repeating the word ‘the’ which ties up the articulatory process and means you can’t rehearse shorter words faster than longer ones as the word length effect disappears.This evidence is for the articulatory process a key element of WMM.
Explanations of Forgetting:Interference theory
Retroactive interference-occurs when you forget a previously learnt task due to the learning of a new task.
Support:
Postman et al.-Lab experiment,
Participants split into two groups who each had to learn a list of paired words e.g cat-tree.The experimental group also had to learn another list of words where the second paired word was different e.g cat-glass.Control group was not given a second list, all participants were asked to recall the words on the first list>The recall of the control group was more accurate than the experimental group.
Proactive interference-occurs when what we know interferes with what we are currently learning.
Support:
Keppel & Underwood-
participants were presented with meaningless 3 letter constant trigrams at different intervals (3,6,9 secs ect).To prevent rehearsal participants had to count backwards in 3s before recalling.Typically trigrams presented first were recalled, irrespective of interval length.Results suggested proactive interference occurred as memory for the earlier constants, which had transferred due to long term memory, was interfering with memory for new constants due to the similarity of the information presented.
Proactive and Retrospective interference are thought to be more likely to occur when the memories are similar e.g new and old telephone numbers
McGeoch & McDonald’s study-
gave participants a list of 10 adjectives (list a).Once these were learnt there was a rest interval of 10 minutes during which they learnt list b, followed by recall.If list b was synonyms of a recall was poor (12%), if list b was numbers this had the least effect (37%) recall, if list b was nonsense syllables this had a lesser effect (26%) recall.This shows interference is strongest the more similar the items are.Only interference, rather than decay can explain such events.
Evaluation of interference theory
-A limitation of research into interference theory is that it lacks ecological validity, majority of research into the theory has been carried out in a lab with a list of words, a situation that is not likely to occur in everyday life.As a result, it may not be possible to generalise from the findings. Baddeley states that there tasks given out are too close to each other and in real life these events would be spaced out more.
Therefore the theory may lack validity.
However, recent research has attempted to address this. Baddeley and Hitch investigated interference on rugby players, they asked them to recall the names of players that they had played over the season.Some had missed games, others had played all games but the time interval was the same.Those players who had played more games forgot proportionately more, suggesting that interference theory is correct as there were more similar memories to disrupt memory (and suggests that decay is wrong)
-Another critiscm of research into interference theory is that, while interference effects happen in everyday life, they don’t happen that often.
Rather special conditions are required for interference to lead to forgetting.The two memories need to be quite similar and for this reason interference is considered a relatively unimportant explanation of everyday forgetting.Anderson concluded that there’s no doubt interference plays a role in forgetting but how much forgetting can be attributed to interference is unclear.
This means other theories are needed to provide a complete explanation of forgetting
-Researchers have often questioned whether interference effects actually cause a memory to disappear or whether effects are just temporary
Ceraso found that if a memory was tested again after 24 hours recognition (accessibility) showed considerable spontaneous recovery whereas recall (availability) remained the same.Suggests interference occurs because memories are temporarily not accessible than have been lost.A study by Tulving and Psotka also supports this.
This research supports the view that interference affects accessibility rather than availability.
Explanations of Forgetting: Retrieval Failure
Tulving and Thompson devised the ‘encoding specificity principle’, which states the closer a cue at retrieval is to the item to be remembered, the higher likelihood of recall.
Context-Dependent forgetting:context-dependant memory refers to improved recall of specific episodes or information when contextual cues relating to the environment are the same during learning and recall
Example:
Godden and Baddeley- investigated the effects of contextual cues.The researchers recruited scuba divers as participants and arranged for them to learn a set of words either on land or underwater.Subsequently they were tested either on land or underwater, so there were four experimental conditions.The results showed that highest recall occurred when the initial context matched the recall environment e.g learning and recall on land.
State-dependant forgetting:state-dependant memory refers to improved recall of specific episodes or information when cues relating to emotional and physical state are the same during encoding and recall.The mental state you are in at the time of learning can also act as a cue
Example:
Goodwin et al.-asked male volunteers to remember a list of words when they were either sober or drunk (those drunk inhibited about 3x the UK drunk driving limit).The participants were asked to recall the lists after 24 hours when some were sober but others had to get drunk again.The recall scores suggest that information learned when drunk is more available when in the same state later.
Evaluation of Retrieval failure
-A strength is the amount of research evidence that has documented the importance of retrieval cues on memory.
Such research includes lab, field and natural experiments as well as anecdotal evidence.For example Tulving and Pearlstone in a lab experiment demonstrated the power of retrieval cues while a field experiment by Abernethy demonstrated the importance of context dependant learning among a group of students studying a course.
The evidence has high ecological validity due to the relevance of everyday memory experiences.
-A strength of this research is that it can be applied to improve recall when needed.
This is used as a strategy to improve recall in eye-witness memory when in cognitive interviews witnesses are asked to describe their mood/emotional state when the incident they have witnessed took place.
This shows how research into retrieval failure can suggest strategies for improving recall in real-world situations such as taking an exam or giving eye witness testimony.
-a strength of the retrieval failure explanation is it’s ability to explain interference effects.
Tulving and Psotka demonstrated that apparent interference effects are due to the absence of cues.Participants were given 6 word lists to learn, each consisting of 24 words split into 6 different categories such as flowers.Participants were either asked to recall the words with free recall or after being given the category (cued recall).The more lists that had to be learnt the worse the recall (retrospective interference effect).However when given cues the effects on interference disappeared and they remembered around 70% of words regardless of how many lists.
This shows that information is there (available) but cannot be retrieved and therefore retrieval failure is a more important explanation of forgetting than interference.
Evaluation of retrieval failure:limitation
-cues could be used to improve exam performance, however this is not very effective.
The issue is the information you learn is related to a lot more than just the cues.In most research on context effects participants learn word lists, however in learning something in everyday life that is far more complex such as Miligram’s research into obedience you are learning about complex associations not easily triggered by a single cue this is called the cue outshining hypothesis where a cues effectiveness is reduced by the presence of better cues.According to Smith and Vela context effects are largely eliminated when learning meaningful material.
This suggests that while the use of retrieval cues can explain instances of everyday forgetting…
Accuracy of Eye-Witness Testimony-leading questions
Laboratory experiment by Loftus and Palmer
Experiment one:
Aim-aimed to show that leading questions could distort eye-witness testimony accounts and so have a confabulating effect, as the account would become distorted by cues provided in the question.
Procedure-45 American students from the university of Washington formed an opportunity sample.Lab experiment with 5 conditions, only one of which was experienced by each participant (independent measures experimental design).7 films of traffic accidents, ranging in duration from 5 to 30 seconds were presented in a random order to each group.After watching there were each asked to answer a question as if they were eye-witnesses about how fast the cars were going when they ‘smashed/collided/bumped/hit/contacted’. Independent variable was the strength of the verb used and he dependant was the speed of the car estimated by participants.
findings-as the strength of the verb increased so did the estimated speed.This seemed to change the schema of events.Loftus didn’t know if this was due to response bias or if the actual memory changed.
Experiment 2:
Aim-to investigate whether participants alter their answer when the wording of a question changes due to response bias or altering their memory reconstruction.This was a question left unanswered from study 1
Procedure-150 students were shown a 1 minute film of a car driving through the countryside followed by four seconds of a multiple traffic accident.The students were then questioned about the film changing the types of question asked (independent variable).50 asked how fast when smashed, 50 when hit and remaining 50 not asked a question at all (control group).A week later dependant variable was measured, without seeing the film again they answered 10 questions.The critical one was ‘did you see any broken glass’.There was no broken glass on the original film.
Findings-smashed 16 saw 34 didn’t, hit 7 saw 43 didn’t, control 6 saw 44 didn’t.
research suggests memory is easily distorted by questioning technique.Results show this effect is not just to do with response bias and for some the memory was actual reconstructed.Consequently this experiment supports the reconstructive memory hypothesis arguing that memory gathered at the time of an event is modified by information gathered after.
Post event discussion
A conversation between co-witnesses or an interviewer and an eyewitness after a crime that has taken place which may contaminate a witness’ memory for the event.
memory contamination may involve false memories which are memories from events that didn’t happen.
Possible causes of false memories:
conformity effect-the eye-witnesses recall changes only because they go along with the accounts of the co-witnesses.They do this either to win social approval or they genuinely believe that the co-witnesses are right and they are wrong
source monitoring-distortion of memories occurs when alternative accounts are heard, which creates confusion.The eyewitness can recall information about the event (accurate and inaccurate) but can’t recall where it came from.This is known as source confusion.
Gabbert et al.-investigated the effects of post-event discussion on the accuracy of eye witness testimony.Her sample consisted of 60 students from the university of Aberdeen and 60 adults recruited from the local community.
Participants watched a video of a girl stealing money from a wallet, they were either tested individually (control) or in pairs (co-witness group).The participants in the co-witness group were told they watched the same video however, they saw different perspectives of the same crime and only one actually witnessed the girl stealing.They then discussed the crime together.All groups then completed a questionnaire based off the event.
Gabbert et al. found that 71% of the witnesses in the co-witness group recalled information they had not actually seen and 60% said that the girl was guilty, despite the fact that they didn’t see her commit the crime.These results highlighted the issue of post-event discussion and the powerful effect this can have on the accuracy of eye-witness testimony.
Evaluation of leading questions and post-event discussions
-A weakness of the theory is that the research applied to it can’t be applied to real life situations because it’s laboratory based.
EWT in real life can be surprisingly accurate while laboratory experiments lack ecological validity as the results don’t reflect real life.For example Guile and Cutshall found that in a real life robbery, nearly all witnesses could correctly identify the perpetrator four months after the crime even when they had discussed the event and been given two leading questions.
Therefore the research into the theory lacks ecological validity and the theory is less valid.
-A strength of the theory is that it has useful real life applications.The justice system is now more accurate at identifying perpetrators.
Psychological research has been used to warn the justice system of problems with eye-witness evidence.Recent DNA exoneration cases have confirmed the warnings of eye-witness identification researchers b y showing that mistaken EWT was the largest single factor in contributing to the conviction of innocent people.
Now police know to avoid leading questions, encourage eye-witnesses to not discuss event and to remember that memories can be reconstructed.
-A limitation of research into misleading information is that it generally does not account for individual differences.
A number of studies have found that the elderly have relatively more difficulty remembering the source of information, even though their memory of an event is unimpaired.Therefore, they are more prone to the effects of misleading information when giving a testimony.
Such research should be highlighted so the justice system understands when to be particularly cautious in avoiding misleading information- for example, all elderly could be offered a cognitive and not police interview.
-The possibility of response bias is another criticism of Loftus and Palmer’s research into eye-witness testimony.
Loftus and Palmer found that leading questions changed the original memory.However Bekerian and Bowers replicated a study of Loftus et al. and found that participants are not susceptible to misleading information if questions are placed in the same order as the original (Loftus did random).This suggests that order has a significant effect and therefore memory change was due to response bias not storage.
This provides an alternative explanation to Loftus and Palmer and highlights the importance of question oder in police interviews.
Accuracy of Eye-witness testimony:anxiety study
study by Johnson and Scott:
Aim-to investigate the effect of anxiety on eye-witness testimony
Procedure-participants were in a laboratory and told to wait in the reception and left alone, the experiment used an independent groups design as participants were exposed to one of two conditions…
1)’no weapon’ participants overheard a conversation in a laboratory about equipment failure.Thereafter an individual left the laboratory and walked past the participant holding a pen, with his hands covered in grease.
2) ‘weapon condition’ participants heard a heated exchange and the sound of breaking glass and crashing chairs before an individual running into the reception area, holding a bloodied letter opener.
Both groups were then shown 50 photographs and asked to identify the person who left the laboratory.They were informed that the suspect may, or may not be present in the photos.
Results-Those who witnessed the man holding the pen correctly identified the target 49% of the time.Whereas those who witnessed the man holding the knife correctly identified the target 33% of the time.
Conclusion-Loftus claimed that the participants who were exposed to the knife has higher levels of anxiety and were more likely to focus their attention on the weapon and not the face of the target, a phenomenon known as the weapon focus effect.Therefore, the anxiety associated with seeing a knife reduces the accuracy of the eye-witness testimony.
Accuracy of Eye-witness testimony: Effects of Anxiety
Christianson & Hubinette:
-found higher recall in witnesses to a real life bank robbery.
-victims of the bank robbery e.g bank clerk (high anxiety) had better recall of the details than the bystanders (low anxiety).
-This suggests that anxiety improves the accuracy of EWT.
Yerkes and Dodson:
-proposed there is a relationship between arousal and performance (called Yerkes-Dodson law) stating that when a crime is witnessed, a person becomes emotionally and physically aroused.Low level of arousal is associated with low level performance (recall + accuracy of EWT).As arousal increases performance increases up to an optimum.After this point as arousal continues, performance begins to decrease.
Evaluation of Anxiety
-A criticism of the weapon effect comes from Pickel who proposed that the reduced accuracy of identification could be due to surprise rather than anxiety.
To test this she arranged for participants to watch a thief entering a hairdressing salon carrying scissors (High threat, low surprise) , handgun (high threat, high surprise) , wallet (low threat, low surprise), and a raw chicken (low threat, high surprise).Identification was least accurate in the high surprised conditions rather than high threat.
This supports the view that the weapon focus effect is related to surprise rather than anxiety.
-A real life study by Yuille and Cutshall contradicts the results of Loftus and Palmer and the weapon focus effect.
They investigated the effect of anxiety in a real life shooting, in which one person was killed and another was seriously wounded.21 witnesses were originally interviewed by investigating police and 13 of them aged between 15-32 agreed to take part in the follow up by Yuille and Cutshall 4-5 months later.They found that the witnessed were accurate in their eyewitness accounts 5 months later and little change found in their testimonies.All of the major details were the same and only the minor details, including estimates of age, height and weight changed.Furthermore, witnesses avoided leading questions and the anxiety experienced at the time of the event has little or no effect on their subsequent memory for the event.
These results refute the weapon focus effect and results of Loftus and show that in real life cases of extreme anxiety, the accuracy of eye-witness testimony is not affected.
-It has been suggested that on key extraneous variable in many studies of anxiety is emotional sensitivity.
In a study by Bothwell et al. participants were tested for personality characteristics and labelled as either ‘neurotic’ (tends to become anxious) or ‘stable’ (less emotionally sensitive).It was found that ‘stable’ participants quickly showed rising levels of accuracy as stress levels increased, whereas the opposite was true for ‘neurotics’.Deffenbacher et al. deemed that modest effect sizes shown in many studies may be the result of averaging out low accuracy and high accuracy scores of both sensitive and non sensitive patients.
These studies suggest that individual differences may indeed play an important role in the accuracy of EWT.
-Fazey and Hardy suggested that a more complex relationship between anxiety and performance than the Yerkes-Dodson model.
Their catastrophe model 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 inverted U only describes increases in physiological anxiety.
This, therefore suggests that an alternative model, one that Deffenbacher et al. believes fits better with research findings, especially those of real life eye-witnesses
Accuracy of Eye-Witness Testimony: The Cognitive Interveiw
Geiselman et al. devised the cognitive interview to overcome many of the problems that arise from the standard interview.For example…
Eye-witnesses might be asked to close their eyes and mental travel back to the scene of the crime: what was the weather like? what sounds were there? How were they feeling? What were they doing just before hand?Based of the encoding specificity principle, recalling internal and external factors will act as cues enabling recall.
Asked to report on every detail they can, even if it seems irrelevant or trivial.They are encouraged to go over points and elaborate, and active listening and open questions are used to encourage dialogue.It’s useful as eye-witnesses might not know which cues are relevant.Furthermore, minor details might act as cues for more important ones.
Asked to recall from a different perspective.This could be another witness, passer-by or the perpetrator themselves if that is not too traumatic.Doing this encourages eye-witness to not rely on their schemata (what usually happens in such events) but use a different retrieval path to recall what actually happened.
Asked to recall in a different order e.g reverse.Recalling in reverse order is especially effective due to the recency effect: we recall the most recent events most clearly and therefore are more likely to be accurate in our recall and not ‘fill in’ information wrongly based on our schema.
A standard police interview:
-revolves around interviewer (who does most of the talking) rather than the witness
-specific questions e.g ‘how tall was the criminal’
-questions are predetermined
-interviewees are discouraged from adding too much information
-leading questions may be used
