Memory Flashcards
What is the Multi-store Model of Memory?
- proposed by Atkinson & Shiffrin (1968)
- suggested that memory is made up of three components: sensory register (SR), short‐term
memory (STM) and long‐term memory (LTM). - According to the model, memories are formed sequentially
and information passes from one component to the next, in a linear fashion.
specific types of coding:
- Coding
- Duration
- Capacity
Coding - refers to the
way in which information is changed and stored in memory.
Duration - refers to the length of time that information is held in the memory store.
Capacity - refers to the amount of information that can be
stored.
What In the Sensory Register?
- Functions to retain information for long enough to decide if information is worthy for further processing
- There are many sensory stores, the two important examples of sensory stores are: visual sensory memory (iconic) and echoic memory.
- Information that isn’t attended to is lost quickly
- After information is selected from sensory memory and is attended to, it is transferred to short-term memory
What is the Short Term Memory?
- Information that is attended to is passed to STM
- limited capacity of 7+/‐2 ‘chunks’ of information
- limited duration of approximately 20 seconds.
- Information in our STM is coded in an acoustic format.
- For example, if you were trying to remember a phone number, you might repeat the
number over and over in your head.
What is the Long Term Memory Store?
- If the information is rehearsed it is transferred to LTM
- has an unlimited capacity
- lifetime’s duration.
- Information in LTM is coded semantically (by meaning)
- can be retrieved from LTM to STM when required.
Peterson & Peterson (1959) Duration of STM
Aim:
Method:
Results:
Conclusion:
Evaluation:
Aim:
- To investigate the duration of short-term memory, and provide empirical evidence for the multi-store model.
Method:
- The participants were 24 male and female university students. The verbal items tested for recall
were 48 three‐consonant nonsense syllables (such as JBW) spelled out letter by letter ‘trigrams’.
- There were also cards containing three‐digit numbers (such as 360).
- The researcher spelled the syllable out and then immediately said a three‐digit number.
- The participant had to count down backwards in either 3s or 4s (as instructed) from that number.
- This was to prevent repetition of the trigram by the participant. - At the end of a preset interval of between 3 and 18 seconds a
red light went on and the participant had to recall the trigram.
Results:
- Peterson & Peterson found that the longer the interval the less accurate the recall.
- At 3 seconds, around 80% of the trigrams were correctly recalled, whereas at 18 seconds only 10% were correctly
recalled.
Conclusion:
- STM has a limited duration of
approximately 18 seconds.
- Furthermore, if we are
unable to rehearse information it will not be passed to
LTM, providing further support for the MSM.
Evaluation:
Strengths:
Well controlled lab study. e.g. instructions to pps were standardized. improves internal validity of study as extraneous variables were controlled.
Weakness:
This experiment has low ecological validity as people do not try to recall trigrams in real life. (Lab setting is artificial so lacks ecological validity, therefore results can’t be generalised to real-life.)
Learning nonsense trigrams is not a day-to-day activity, so task lacks mundane realism.
Use of students is problematic. results may not relate to general population and so lack population validity. Uni students are above average intelligence, so memory task with another group may show different results.
Bahrick (1975) Duration of LTM
Aim:
Method:
Results:
Conclusion:
Evaluation:
Aim:
To investigate the duration of LTM.
Method:
- 392 American university graduates were shown photographs from their high school yearbook and
for each photograph participants were given a group of names and asked to select the name that matched the photographs.
Results:
- 90% of the participants were able to correctly match the names and faces 14 years after
graduating
- 60% of the participants were able to correctly match the names and faces 47 years after
graduation.
Conclusion:
- Bahrick concluded that people could remember certain types of information, such as names
and faces, for almost a lifetime.
- These results support the MSM and the idea that our LTM has a lifetime duration (at least 47 years), and is semantically encoded.
Evaluation:
STRENGTHS:
A strength of this study is that it has high ecological validity. This is because it is a field experiment. Recalling school friends is not an artificial task and is actually something you might find yourself doing in everyday life. For example, when joining social networking sites such as Facebook you may find yourself trying to remember your classmates’ names, and when somebody from school adds you, you may find yourself looking at their photo trying to place them.
WEAKNESS:
A limitation of this study is that researchers had poor control over the experiment. It was not recorded whether the participants were still in contact with anyone from school before they were tested. For all the researchers knew there could have been some school reunion the week before in which case of course the pps would remember their classmates.
A final limitation of this study is that the findings are ungeneralisable. The reasons for this are two fold. Firstly, this study only tells us about the duration of LTM for high school memories, not the duration of LTM in general. Secondly, the study lacks population validity as the sample were all American and so the results may not apply to other nationalities.
Miller (1956)
Aim:
Method:
Results:
Conclusion:
Evaluation:
Aim:
to investigate the capacity of short term memory
Method:
* participants were given a list of words and asked to remeber them and how many they remebered was taken in.
Results:
- This research suggested that organising input into chunks allowed the STM to cope with about seven ‘chunks’, and this was why more than seven digits, words or even musical notes could be remembered successfully
.
- When we try to remember a phone number, which has 11 digits, we chunk the information into groups, for example: 0767…819…45…34, so we only need to remember four chunks of information and not 11 individual digits.
Conclusion:
Organisation (or ‘encoding’) can extend the capacity of STM and enable more information to be stored there.
Evaluation:
STRENGTHS:
- Miller’s (1956) theory is supported by psychological research.
- For example, Jacobs (1887) conducted an experiment using a digit span test, to examine the capacity of short-term memory for numbers and letters.
- Jacobs used a sample of 443 female students (aged from 8-19) from the North London Collegiate School. Participants had to repeat back a string of numbers or letters in the same order and the number of digits/letters was gradually increased, until the participants could no longer recall the sequence.
- Jacobs found that the student had an average span of 7.3 letters and 9.3 words, which supports Miller’s notion of 7+/-2.
WEAKNESS:
Although Miller’s (1956) theory is supported by psychological research, he did not specify how large each ‘chunk’ of information could be and therefore we are unable to conclude the exact capacity of short-term memory. Consequently, further research is required to determine the each size of information ‘chunks’ to understand the exact capacity of short-term memory.
Finally, Miller’s (1956) research into short-term memory did not take into account other factors that affect capacity. For example, age could also affect short-term memory and Jacobs (1887) research acknowledged that short-term memory gradually improved with age.
Types of Long Term Memory?
Episodic memory
This type of memory involves the storage and retrieval of personal experiences and events, such as what you had for breakfast this morning or where you went on vacation last summer.
Types of Long term memory?
Semantic Memory
This type of memory involves the storage and retrieval of general knowledge and information, such as facts and definitions.
Types of Long term memory?
Procedural Memory:
This type of memory involves the storage and retrieval of skills and habits, such as riding a bike or playing the piano.
Declarative Memory:
This type of memory encompasses both episodic and semantic memory, involving the conscious recall of information.
Non-declarative Memory:
This type of memory encompasses procedural memory, involving the unconscious storage and retrieval of skills and habits.
Evaluation Of Long Term Memory?
(2 STRENGTHS + 1 WEAKNESS)
STRENGTHS:
case studies such as clive wearing who had damage to his episodic memory ( lived in a time span of 20 seconds couldn’t remember memories of children etc) but not his procedural as he could still conduct a choir and play piano, showing that different types of ltm exist
brain scans such as pet show different parts of the brain being active when the LTM is active. semantic is associated with temporal lobe, episodes is associated with temporal lobe and hippocampus and procedurel is associated with basal ganglia and cerebellum
WEAKNESS:
the fact its based upon case studies is problematic as case studies are on singular people and the same conditions could affect people differently thus they can’t be generalised and classed as representative.
Briefly describe the working memory model. (4 marks)
The working memory model proposes that the short term memory isn’t unitary, but is split into separate stores. One store is the central executive which is involved in attention and higher mental processes. There is also the episodic buffer which acts as a temporary back-up store for the central executive. A third store is the phonological loop, associated with sound based information. Finally, there is the visuo-spatial sketchpad, associated with visual information.
What is the Central Executive?
The central executive is the ‘boss’ of the WMM. It controls attention and directs information to the two
slave systems, the phonological loop and visuo‐spatial sketchpad. The central executive can process information from any sensory modality.
What is the The phonological loop?
The phonological loop is a temporary storage system for verbal information (held in a speech‐based form)
which has two components, the articulatory control process (the ‘inner voice’) and the phonological store
(the ‘inner ear’). The articulatory control process allows for subvocal repetition of acoustic information and the phonological store is a temporary storage space for coding acoustic information, which has a
limited capacity.
What is the The visuo‐spatial sketchpad?
The visuo‐spatial sketchpad is a temporary storage system for visual and spatial information which also has
two components, the inner scribe and the visual cache. The inner scribe deals with the manipulation of mental images and the visual cache has a limited capacity for coding visual and spatial information.
What is The episodic buffer binds
The episodic buffer binds and integrates information from all of the components and passes the information to long‐term memory (LTM). It therefore codes both visual and acoustic information, but also
has a limited capacity.
What is Semantic memory?
Semantic memory is also a type of explicit memory, which includes memory for knowledge, facts, concepts
and meaning about the world around us. For example, knowing that London is the capital of England is an
example of a semantic memory and so too is knowing that the legal age to drive in the UK is 17 years old.
- Semantic memories often start as episodic memories, as we acquire knowledge based on our personal
experiences, but they are not ‘time‐stamped’ in the same way nor do they remain closely associated with
a particular event (episode). - Like episodic memories, the strength of semantic memories is determined by
the strength of the emotions experienced when the memory is coded, although semantic knowledge is
often less personal in its nature and can relate concepts such as language and maths.
What is Procedural memory?
Procedural memory is a type of implicit memory, which includes memory of how to perform certain tasks,
actions or skills, such as swimming, reading and writing which have become ‘automatic’.
- Procedural memories are implicit and therefore difficult to explain in words to someone else.
- They are often acquired through repetition and practice, for example, when we learn to ride a bike or drive a car.
- Many formed early in life, for example, walking. It is important that these become like second nature to us so that we can focus our direct attention onto other everyday tasks
- Procedural memories are associated with the cerebellum and motor cortex.
Evaluating the working memory model
2 STRENGTHS + 1 WEKANESS
STRENGTHS:
- Support for the WMM comes from the case study of Patient KF, who was injured in a motorcycle accident.
- Following his accident, KF was able to recall stored information from his LTM; however, he had issues with his STM.
- He was able to remember visual images, including faces, but was unable to remember sounds (acoustic information).
- This suggests that there are at least two components within STM, one component for visual information and one for acoustic information.
- The research into KF supports the WMM and the idea of two slave systems, the phonological loop and the visuo‐spatial sketchpad, therefore providing support to the WMM and the idea of a multi‐component STM system.
**Further support for the WMM comes from dual‐task studies by Baddeley and Hitch (1976). **
* Dual‐task studies require participants to complete two tasks at the same time.
* In one condition, participants may be required to complete two acoustic‐based tasks, such as simultaneously remembering a series of digits and completing a verbal reasoning task.
* In another condition, participants may be required to complete one acoustic based task and one visual based task, for example, remember a series of digits and copying a drawing.
* When both tasks require the participants to use their phonological loop, their ability to perform the tasks is impaired.
* However, when one task requires the participant to simultaneously use their phonological loop (remembering a series of numbers) and the other requires their visuo‐spatial sketchpad (copying a drawing) then their performance is not impaired.
* Dual‐task studies provide evidence for the existence of multiple components within our STM and support the idea of a separate phonological loop and visuo‐spatial sketchpad
WEAKNESS:
However, one issue with the WMM is that it only focuses on STM, and the link between the WMM and LTM is not fully explained.
* The WMM provides a detailed description of our STM, but no information on how information is processed and transferred from STM to LTM and back again.
* Therefore, the WMM is an incomplete model of memory and other theories/models are required to gain a complete picture of this complex cognitive phenomenon.
FORGETTING
What are the different explanations of forgetting?
different explanations for forgetting:
* proactive interference
* retroactive interference
* retrieval failure due to the absence of cues.
FORGETTING
What is meant by interference?
- Interference theories suggest that forgetting is caused by competing memories, either because existing memories interfere with the learning of new information (proactive interference) or because new information interferes with previously learnt information (retroactive interference).
- Furthermore, forgetting can also occur because information cannot be retrieved, due to insufficient cues to trigger memory.
FORGETTING
What is menat by proactive interference?
- Proactive interference occurs when old information stored in long‐term memory (LTM), interferes with the learning of new information.
- This usually occurs when the new information is similar to the old information.
- An everyday example of proactive interference is when you get a new mobile phone number: your memory for your old number will disrupt your attempts to remember your new number.
FORGETTING
KEY STUDY: proactive interference
(Keppel & Underwood (1962))
AIM:
METHOD:
RESULTS:
CONCLUSIONN:
**Aim: **
To investigate the effect of proactive interference on LTM.
Method:
In an experiment that is very similar to that conducted by Peterson & Peterson (1959), participants were presented with meaningless three‐letter consonant trigrams (for example, THG) at different intervals (3, 6, 9 seconds, etc.) To prevent rehearsal the participants had to count backwards in threes before recalling.
Results: Participants typically remembered the trigrams that were presented first, irrespective of the interval length.
Conclusion: The results suggest proactive interference occurred, as memory for the earlier consonants (which had transferred to LTM) interfered with the memory for new consonants, due to the similarity of the information presented.
FORGETTING
What is meant by retroactive interference?
- Retroactive interference occurs when the learning of new information interferes with the recall of old information from LTM.
- For example, once you have learned your new mobile number, it is often very difficult to recall your old number.
FORGETTING
Key Study: RETROACTIVE INTERFERENCE
Baddeley & Hitch (1977)
**Aim: **
To investigate retroactive interference in everyday memory.
Method:
The sample comprised rugby union players who had played every match in the season and players who had missed some games due to injury. The length of time from the start to the end of the season was the same for all players, and players were asked to recall the names of the teams they had played against earlier in the season.
Results: The players who had played the most games forgot proportionately more games than those who had played fewer games due to injury.
Conclusion:
Baddeley and Hitch concluded that this was the result of retroactive inference, as the learning of new information (new team names) interfered with the memory of old information (earlier team names).
FORGETTING
Evaluating Interference Theories
STRENGTH:
P= Supporting evidence from McGeoch & Mcdonald
E= studied retroactive interference by changing amount of similarity between 2 sets of materials, ppts first learnt a set of words when they had to learn another list
E= ppts recall of the original list was lower with synonyms compared to acronyms, unrelated adjectives, numbers of nonsense syllables.
L= demonstrates interference strongest when memories similar.
P= Support- application to real life behaviour
E= student should avoid looking @ similar materials together when revising for exams.
E= can easily be done by leaving gap between revision of same subject topic or interleaving between diff topics.
L= effectiveness of revision methods reinforces interference theory claims ab impact of similar info on forgetting.
WEAKNESS:
P= Limitation- lacks ecological validity
E= recalling list of words not everyday event
E= Baddley and hitch found rugby players recall of team from 3 weeks ago better if 0 matches played since.
L= Demonstrates accurate recall did not depend on how long ago matches took place but games played in mean time illustrating interference as reason for forgetting
P= limitation- fails to explain loss of info may only be temporary
E= Tulving demonstrated apparent interference effects are actually due to absence of cues
E= PPTS given 5 word lists organised into catergories recall was 70% for 1st word list but fell w addition lists, when told name of catergories rose again to 70%
L= demonstrates interference theory too simplistic, retrieval failure better exp as can account for findigns of Tulving through encoding specificity principle.
FORGETTING:
Retrieval Failure Due to Absence of Cues
- Another type of forgetting occurs when information cannot be retrieved because of insufficient cues to trigger memory.
- ** Tulving and Thomson (1973)** proposed the encoding specificity principle and argued that memory is most effective when information that was present at the time of coding is also present at the time of retrieval.
- Furthermore, they suggested that environmental cues and mental cues aid recall.
- Environmental cues include the room in which you learn information, and mental cues include your emotional state.
- Consequently there are two types of retrieval failure due to the absence of cues:
- 1) context‐dependent failure - occurs when environmental cues are missing
- 2) state‐dependent failure- occurs when an individual’s emotional state is different when trying to recall information.
FORGETTING:
Context‐Dependent Forgetting
Key Study: Godden & Baddeley (1975)
+ EVALUATION
Aim:
* To investigate the effect of contextual cues on recall (i.e. would memory for words learned and recalled in the same environment be better than memory for words learned and recalled in different environments?)
Method:
* Their sample comprised 18 participants (13 males and 5 females) from a university diving club, who were divided into four conditions:
1) learning words on land
2) recalling on land
2) learning words on land and recalling underwater
3) learning underwater and recalling underwater
4) learning underwater and recalling on land.
- The experiment was a repeated measures design with each participant taking part in all four conditions, over four separate days.
- In all four conditions participants were presented with 38 words, which they heard twice.
- After hearing all 38 words the participants were instructed to write all the words they could remember, in any order.
Results:
The words learned underwater were better recalled underwater and words learned on land were better recalled on land.
**Conclusion: **
It is, therefore, reasonable to conclude that the environmental cues (context) improve recall.
EVALUATION:
Although the results suggest that environment cues aid memory recall, Godden & Baddeley didn’t control many other variables. The divers took part in the experiment at different times of the day and at different diving locations. Therefore, each diver would have experienced other contextual cues, which may have affected their memory. Therefore, we are unable to conclude whether the results of Godden & Baddeley’s research is due to the on land/underwater contextual cues, or another contextual cue provided by the different time of day or diving location.
▪ Godden & Baddeley used a repeated measures design, as each diver took part in all four conditions. It is possible that the divers worked out the aim of the experiment and displayed demand characteristics or order effects. By the fourth trial the participants may have demonstrated practice effects where their recall improved as a result of completing the experiment multiple times, or even fatigue effects where their results declined as a result of boredom. A more suitable experimental design would have been independent measures. However, this would have required significantly more participants, which would be difficult to achieve when recruiting trained divers. Furthermore, with a sample of just 18 divers the conclusions drawn should be treated with caution. Additionally, the context examined in their study is extreme and provides little insight into context‐dependent forgetting in everyday life.
▪ Godden & Baddeley could also be criticised for breaking ethical guidelines, in particular protection from harm. In their report, they said: ‘One diver was nearly run over during an underwater experimental session by an ex‐army, amphibious DUKW’, and therefore more precautions should have been taken to ensure the safety of their participants.
FORGETTING:
State‐Dependent Forgetting:
State‐Dependent Forgetting:
- When the emotional state that an individual is in serves as an aid to memory recall, there is a risk that state‐dependent forgetting will occur when the same psychological state is not experienced.
- This is often the case with alcohol intoxication and the absence of accurate memories when sober.
forgetting:
Key Study: Carter & Cassaday (1998):
** Aim:**
* Carter & Cassaday (1998) examined state‐dependent forgetting using anti‐histamine drugs.
* These are typically administered as hay fever relief to sufferers but are also known for their sedating effect. This can make the individual feel drowsy, and therefore not as alert as they would normally be, providing a comparison to everyday non‐drug‐induced behaviour.
Procedure:
* Participants were tasked with learning a list of words and excerpts from a text and then asked to recall the information at a later point. There were four conditions in their experiment:
1) learn the words/text after taking anti‐histamine and recall after taking anti‐histamine
2) learn the words/text without anti‐histamine and recall without anti‐histamine
3) learn the words/text after talking anti‐histamine and recall without anti‐histamine drugs
4) learn the words/text without anti‐histamine and recall after taking the anti‐histamine drugs
Findings:
* In the conditions where the learning and recalling state matched (i.e. after taking the drugs on both occasions or not taking the drugs both occasions) memory was improved.
* Consequently, when the physiological state of the participants was different recall was significantly poorer.
Conclusion:
When the physiological/emotional cues that are present at the time of encoding are missing at the time of retrieval (recall), state‐dependent forgetting is likely to occur.
EVALUATION:
There is research support for the effect of state‐dependent retrieval failure, which occurs when an individual’s emotional state at the time of learning is different to their emotional state at the time of recall. For example, Goodwin et al. (1969), asked male volunteers to remember lists of words when they were either drunk or sober. The participants were then asked to recall the words 24 hours later, in either a drunk or sober state. The results of Goodwin et al. support Godden and Baddeley, as words learned when drunk were better recalled when drunk, and words learnt when sober were better recalled when sober. These results support the idea of state‐dependent retrieval failure and demonstrate the power of ‘state’ on recalling information.
▪ There is research support for state‐dependent forgetting using a range of different substances to create an alternative state of consciousness. Darley et al., (1973) researched the impact of marijuana on an individual’s recollection. It was found that individuals who were under the influence of marijuana when they put money in a ‘safe place’ were less able to recall where this location was once they were no longer under the influence of the drug. This evidence adds weight to the argument that the emotional and physiological state that a person is in at the time of encoding is important at the time of retrieval.
▪ There are issues with determining a cause and effect relationship with retrieval failure as an explanation of forgetting. Nairne (2002) criticised research in this area suggesting that there is merely a correlation between cues present at the time of encoding and cues present at the time of later retrieval. He goes further and suggests that the cues present do not in themselves cause the retrieval failure (or success), but are simply associated with it. This would mean that the cue‐dependent (context and state) explanations of forgetting due to retrieval failure, and in fact circular in nature rather than linear and psychologists are unable to conclude whether a lack of cues actually causes retrieval failure.
What is meant by eyewitness testimony
- An eyewitness testimony is the evidence given in court or a police investigation by someone who has witnessed a crime or accident.
- For many years psychologists have investigated the factors that can affect the accuracy of eyewitness reports, in order to ensure that the evidence provided during investigations is reliable and accurate.
- Psychologists have identified several factors that can have a detrimental effect on the accuracy of eyewitness reports
THIS INCLUDES:
* misleading information, through leading questions
* post‐ event discussion
* anxiety.
Misleading Information – Leading Questions
Loftus & Palmer (1974) Experiment 1
Aim:
To investigate the effect of leading questions on the accuracy of eyewitness testimony.
Method:
The sample was 45 American students, who were divided into five groups of nine. In an independent measures design, all of the participants watched a video of a car crash and were then asked a specific question about the speed of the cars. Loftus & Palmer manipulated the verb used in the question, for example: “How fast were they cards going when they smashed/ collided/ bumped/ hit/ contacted with each other?” They found that the estimated speed was affected by the verb used. For example,
participants who were given the verb ‘smashed’ reported an average speed of
40.5 mph, whereas participants who were given the word ‘contacted’
reported an average speed of 31.8 mph, an overall difference of 8.7 mph.
**Conclusion: **
The results show clearly that the accuracy of eyewitness testimony is affected by leading questions and that a single word in question can significantly affect the accuracy of our judgements
Loftus & Palmer (1974) – Experiment 2
**Aim: **
To investigate further how leading questions can affect eyewitness testimony.
Method:
* Loftus & Palmer used a different sample of 150 American students, who were divided into three evenly‐sized groups.
* All of the students watched a one‐minute video depicting a car accident and were then given a questionnaire to complete.
* One group was asked: “How fast were the cars going when they smashed into each other?” Another group was asked: “How fast were the cars going when they hit each other?” The final group (control) was not asked about the speed of the vehicles.
* One week later the participants returned and were asked a series of questions about the accident.
* The critical question was: “Did you see any broken glass?” There was no broken glass in the video clip.
Results:
* 32% of the participants who were previously questioned using the verb smashed reported seeing broken glass; 14% of the participants who were previously questioned using the verb hit reported seeing broken glass; and 12% of the control group reported seeing broken glass.
Conclusion:
* The participants who were questioned previously using the verb smashed were significantly more likely to report seeing the broken glass, as a result of the earlier leading question.
* The verb smashed has connotation of faster speeds and broken glass and this question led the participants to report seeing something that was not actually present.
* Their memory for the original event was distorted by the question used one week earlier, demonstrating the power of leading questions.
Evaluating Loftus & Palmer
WEAKNESS:
* Loftus & Palmer’s research has questionable ecological validity. On the one hand, questioning participants about everyday events like a car crash appears to be a genuine measure of eyewitness testimony. However, the participants watched a video of a car crash and witnessed the events unfold from start to finish. In everyday reports of car accidents, witnesses rarely see the whole event; they are either involved in the event directly, or see a small part of the event happen in their peripheral vision. Therefore, their results do not reflect everyday car accidents and we are unable to conclude if eyewitnesses to real accidents, who would have a stronger emotional connection to the event, would be susceptible to leading questions in the same way.
▪ A second weakness of Loftus & Palmer’s research is that their study lacks population validity. Their two experiments consisted of 45 and 150 students from the University of Washington. It is reasonable to argue that the students in their experiment were less experienced drivers, who may be less accurate at estimating speeds. Consequently, we are unable to generalise the results to other populations, for example, older and more experienced drivers, who may be more accurate in their judgement of speeds and therefore not as susceptible to leading questions.
▪ However, Loftus & Palmer’s research took place in a university laboratory and was therefore highly controlled. This high degree of control reduces the chance of extraneous variables, increasing the validity of the results. Furthermore, it is easy for psychologists to replicate their research, to see if the same results are achieved with a different population.
Misleading Information – Post‐Event Discussion
Gabbert et al. (2003)
Aim:
To investigate the effect of post‐event discussion on the accuracy of eyewitness testimony.
Method:
* The sample comprised 60 students from the University of Aberdeen and 60 older adults recruited from a local community.
* Participants watched a video of a girl stealing money from a wallet.
* The participants were either tested individually (control group) or in pairs (co‐witness group).
* The participants in the co‐witness group were told that they had watched the same video; however, they had in fact seen different perspectives of the
same crime and only one person had actually witnessed the girl stealing.
* Participants in the co‐witness group discussed the crime together.
* All of the participants then completed a questionnaire, testing their memory of the event.
Results:
* 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 had not seen her commit a crime.
Conclusion: These results highlight the issue of post‐event discussion and the powerful effect this can have on the accuracy of eyewitness testimony.
EVALUATION:
The results of Gabbert et al. also have questionable ecological validity. The participants in the co‐ witness condition witnessed different perspectives of the same crime, as would typically be the case in real‐life crimes. However, as in Loftus and Palmer’s research, these witnesses knew they were taking part in an experiment and were more likely to have paid close attention to the details of the video clip. Therefore, these results do not reflect everyday examples of crime, where witnesses may be exposed to less information.
▪ Gabbert et al. tested two different populations, university students and older adults, and found little difference between these two conditions. Therefore, her results provide good population validity and allow us to conclude that post‐event discussion affects younger and older adults in a similar way.
▪ Although Gabbert et al.’s results provide an insight into the effect of post‐event discussion on the accuracy of eyewitness testimony, we are unable to conclude why the distortion occurs. The distortion could be the result of poor memory, where people assimilate new information into their own accounts of the event and are unable to distinguish between what they have seen and what they have heard. On the other hand, it could be that the distortion occurs due to conformity and the social pressure from the co‐witness. Further research is required to answer this question.
How does Anxiety affect EWT?
Loftus (1979) / Johnson & Scott (1976)
Anxiety:
Loftus (1979) **[not to be confused with Loftus & Palmer (1974)] **reported the findings of Johnson & Scott (1976) who conducted an experiment to see if anxiety affects the accuracy of eyewitness testimony and facial recognition.
**Loftus (1979) / Johnson & Scott (1976) **
Aim:
* To investigate whether anxiety affects the accuracy of eyewitness testimony.
Method:
* Participants were invited to a laboratory where they were told to wait in the reception area.
* A receptionist who was seated nearby excused herself to run an errand, leaving the participant alone.
* The experiment used an independent groups design, as participants were then exposed to one of two conditions:
1) In the ‘no‐weapon’ condition, participants overheard a conversation in the laboratory about equipment failure. Thereafter, an individual (the target) left the laboratory and walked past the participant holding a pen, with his hands covered in grease.
2) In the ‘weapon’ condition, participants overheard a heated exchange and the sound of breaking glass and crashing chairs.
* This was followed by an individual (the target) running into the reception area, holding a bloodied letter‐opening knife.
* Both groups were then shown 50 photographs and ask to identify the person who had left the laboratory.
* The participants were informed that the suspect may, or may not, be present in the photographs.
Results:
* Those who had witnessed the man holding a pen correctly identified the target 49% of the time, compared to those who had witnessed the man holding a knife, who correctly identified the target 33% of the time.
Conclusion:
* Loftus claimed that the participants who were exposed to the knife had 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 eyewitness testimony.
EVALUATION:
- A real‐life case study by Yuille & Cutshall (1986) contradicts the results of Loftus (1979) and the weapon focus effect. Yuille & Cutshall investigated the effect of anxiety in a real‐life shooting, in which one person was killed and another person seriously wounded. 21 witnesses were originally interviewed by investigating police and 13 witnesses, aged between 15 and 32, agreed to take part in Yuille and Cutshall’s follow‐up research interview, 4–5 months later. Yuille and Cutshall found that the 13 witnesses who took part in the follow‐up interview were accurate in their eyewitness accounts five months later, and little change was found in their testimonies. All of the major details of their reports remained the same and only minor details, including estimates of age, height and weight, changed. Furthermore, the witnesses avoided responding in a biased way to leading questions and the anxiety experienced at the time of the event had little or no effect on their subsequent memory for the event. These results refute the weapon focus effect and the results of Loftus (1979), and show that in real‐life cases of extreme anxiety, the accuracy of eyewitness testimony is not affected.
▪ Loftus’ (Johnson & Scott’s) research has been criticised for lacking ecological validity. Although the participants were waiting in the reception area outside the laboratory, they may have anticipated that something was going to happen, which could have affected the accuracy of their judgements. Furthermore, the results from real‐life case studies (see above) refute the findings of Loftus and suggest that her results do not represent real‐life cases of extreme anxiety.
▪ A final criticism of Loftus (Johnson & Scott) is that numerous ethical guidelines were broken. The participants were deceived about the nature of the experiment and not protected from harm. Loftus (Johnson & Scott) exposed some of the participants to a man holding a bloodied knife, which could have caused extreme feelings of anxiety. This is an issue, as these participants may have left the experiment feeling exceptionally stressed and anxious, especially if they, or someone they knew, had been involved in a knife crime.
What is meant by the cognitive interview?
- The cognitive interview was developed in response to criticisms of the traditional police interview.
- Fisher et al. (1987) studied police interviews in Florida and found that witnesses were often presented with a series of short, closed questions, which attempted to elicit facts.
- Furthermore, the police would often ask questions in a sequence that was not synchronised with the events that had taken place.
What are four key principles that they believed would enhance recall?
Context reinstatement (CR) :
* is when a person mentally recalls the context of the event.
* For example, a person might recall the time of day, the weather, who they were with, or even their feelings.
* These details can then act as a trigger, to help the person recall more information.
* There are clear links here between this and context‐dependent and state‐dependent remembering.
Report everything (RE)
is when a person recalls every detail they can remember, even those that may seem trivial.
**Recall from changed perspective (CP) **
is when a person considers the event from someone else’s point of view.
For example, they might consider what the offender saw.
**▪ Recall in reverse order (RO). **
where a person recalls the events in reverse chronological order.
COGNITIVE INTERCVIEW:
Key Study: Geiselman (1985)
Aim:
* To examine the effectiveness of the cognitive interview.
**Method: **
* A sample of 89 students watched a video of a simulated crime.
* Two days later the students were interviewed using the standard police interview or the cognitive interview.
Results:
* The students who were interviewed using the cognitive interview recalled significantly more correct information than those interviewed using the standard interview.
* In addition, the number of errors (incorrect items recalled) by both groups was similar.
Conclusion:
* The cognitive interview is effective in improving the quantity of information recalled and does not lead to an increase in incorrect information.
**Evaluating the Cognitive Interview **
▪ The results of Geiselman have been support by other research, including Fisher et al. (1989). These researchers examined the effectiveness of the cognitive interview in real police interviews. 16 experienced detectives recorded a selection of their interviews, using a standard interviewing technique. The detectives were then divided into two groups. One group was trained to use the cognitive interview, while the other (control) group continued using the standard interview. After training, their subsequent interviews were recorded and analysed. The trained detectives elicited 46% more information after their cognitive interview training, in comparison to the control group. Where it was possible to confirm the information, over 90% of it was found to be accurate. These results support the findings of Geiselman, using real police interviews, and provide support for the effectiveness of the cognitive interview.
▪ Although the cognitive interview increases the quantity of information recalled, research has found that the cognitive interview is still susceptible to misleading information. Centofanti & Reece (2006) showed participants a video of a bank robbery and then provided participants with a misleading or neutral post‐event summary. On average the participants who were questioned using a cognitive interview, recalled 35% more information. However, the participants in both conditions were equally susceptible to misleading information. Therefore, although the cognitive interview enhances the quantity of information recalled, interviewers need to be careful that participants are not exposed to misleading information in the form of leading questions or post‐event discussion.
▪ Although research supports the effectiveness of the cognitive interview, Kebbell & Wagstaff (1996) have found that police typically use interviewing techniques that limit the quantity of information provided, rather than those that improve accuracy. Furthermore, the cognitive interview requires special training and many police forces have not provided more than rudimentary training, which explains why the cognitive interview is not readily used.
