memory Flashcards
(93 cards)
1
Q
what is short term memory?
A
a limited capacity memory store, coding is mainly acoustic, capacity is between 5-9 items and the duration is about 18 seconds
2
Q
what is long term memory?
A
a permanent memory store, coding is mainly semantic, has unlimited capacity that can store for up to a lifetime
3
Q
what is coding?
A
the way in which information is stored in various memory systems
4
Q
what is capacity?
A
the amount of information that can be stored
5
Q
what is duration?
A
how long memories can be stored
6
Q
what was the procedure for Alan Baddeley’s research on coding?
A
- gave different lists of words to four groups of participants
group 1: (acoustically similar)
group 2: (acoustically dissimilar)
group 3: (semantically similar)
group 4: (semantically dissimilar)
- participants were shown the original words and asked to recall them in the correct order.
7
Q
what were the results of Baddeley’s research on coding?
A
- When they immediately recalled from the STM, they struggled the most with acoustically similar words
- When they recalled the words after 20 mins, with their LTM, they did worse on semantically similar words
- these findings suggest that STM is acoustically coded and LTM is semantically coded
8
Q
strength of Baddeley’s research into coding - separate memory stores
A
- identified a clear difference between the two memory stores
- although later research showed some exceptions, these ideas have stayed the same over time
- this was important in understanding the memory system and understanding the MSM
9
Q
weakness of Baddeley’s research into coding - artificial stimuli
A
- used artificial stimuli instead of meaningful
-Baddeley’s findings do not tell us about memory tasks in everyday life - when people are using memory in everyday life, they may use semantic memory even in STM
- this suggests that the findings from the study have limited application
10
Q
How did Jacobs (1887) find about capacity?
A
- began measuring digit span e.g how many digits the participant can recall at once is their capacity
- found that the mean span for digits was 9.3 and for letters it was 7.3
11
Q
how did George Miller (1956) find out about capacity?
A
- noted different things come in sevens and thought that the span of the STM is 7 + or - items
- found that by chunking, people have the capacity they can recall 5 words as easily as letters
12
Q
strength of Jacob’s study of capacity - a valid study
A
- has been replicated
- the study is very old and old studies often lack adequate controls on variables
-despite this, Jacob’s findings have been confirmed by more recent, better controlled studies - this hows that Jacob’s study is valid
13
Q
weakness of Miller’s study on capacity - not so many chunks
A
- one limitation is Miller may have overestimated STM capacity
- Cowan (2001) reviewed other research and suggested that capacity may only be 4 + or - 1 chunks
- this suggests the lower end of his estimate may be more correct
14
Q
what happened in Peterson and Peterson (1959) study on STM duration?
A
- laboratory test on 24 psychology students in 8 trials
- in each trial, they were given trigrams to recall at different intervals, counting backward
- told to stop at 3,6,9,12,15 or 18 seconds) (retention interval)
15
Q
what were the findings of Peterson and Peterson (1959) study on duration?
A
- after 3 seconds recall was 80%, after 18 seconds it was 3%
- concluded that information vanishes rapidly from STM if participants are not able to rehearse information, duration is about 18 seconds
16
Q
what was the procedure of Bahrick et al (1975) study into duration of LTM?
A
- studied 392 american participants between the ages of 17 and 74 where they obtained their yearbooks
they tested their recollection of the people through photos and free recall with their names
17
Q
what were the findings of Bahrick et al (1975) ?
A
-those tested within 15 years were 90% accurate in photo recall
- after 48 years, recall declined to about 70% for photo recall
- free recall has 60% accuracy after 15 years, dropping to 30% after 48 years
- this shows that LTM may last up to a lifetime for some material
18
Q
limitation of Peterson and peterson (1959) - stimulus material was artificial
A
- the study is not completely irrelevant as we may try to remember meaningless ideas
- recalling trigrams does not appear in everyday life
- lacks external validity
19
Q
strength of Bahrick et al (1975) - high external validity
A
- the researchers investigated meaningful memories
- when studies on LTM were conducted with meaningless pictures to be remembered, the recall rate was not as high (Shepard 1967)
- this suggests that Bahrick et al’s study reflects a more realistic viewpoint on LTM
20
Q
describe Atkinson and Shiffrin (1968) multiple store model
A
information enters the sensory store and through attention enters the STM. it stays in the STM by rehearsal and can be transferred to the LTM through transfer. It either stays in the LTM or through retrieval can go to the STM. it can be forgotten or decay at any time
21
Q
strength of MSM - research support
A
- one strength of the MSM is support from studies that show that STM and LTM are different
- for example , Baddeley found that we tend to mix up words that sound similar when we are using our STM, but we mix up words that tend to have similar meaning of capacity and duration
22
Q
couterpoint of a strength of MSM - research support isn’t as valuable
A
- in everyday life, we form memories related to all sorts of things, something that is not shown in experiments as they often use digits
- this means that the MSM may not be as applicable and valid to everyday life as we thought
23
Q
weakness of MSM - more than one STM store
A
- one limitation of the MSM is the evidence of more than one STM store
- Tim Shallice and Elizabeth Warrington (1970) studied KF, who had amnesia from a brain injury
- KF’s STM for digits was poor when they were read aloud to him but he was much better when he read the digits himself
- this means that there may be more than one form of STM
24
Q
weakness of MSM - elaborative rehearsal
A
- another limitation of the MSM is prolonged rehearsal is needed for the transfer to the LTM
- MSM says that the more you rehearse something, the more likely it is to transfer to LTM (prolonged rehearsal)
- Fergus Craik and Michael Watkins (1973) found that the type of rehearsal is more important than the amount
- elaborative rehearsal is needed for long term storage (this occurs when you link the information to your existing knowledge)
- this means that information can be transferred to the LTM without prolonged rehearsal
- this suggests that the MSM does not fully explain how long term storage is achieved
25
how does the case of HM support MSM?
- HM went under brain surgery to relive his epilepsy
- his hippocampus was removed from both sides of his brain
- when his memory was assessed in 1955, he though that the year was 1953 and that it was 1953
- he could not form long term memories and would read things multiple times without realising
- despite this he performed well on tests of STM
- individual case study but good real life example
26
how does Sperling (1960) support the limited duration of the sensory register?
- tested the iconic sensory register (memory store)
- participants saw a grid of digits and letters for 50 milliseconds
- they were asked to either write down all 12 items or they would hear a tone immediately and after the exposure, they should write down the row indicated
- when asked to report the whole thing, their recall was poor
27
who proposed the idea of multiple LTM and why?
Tulving (1985) and he said that the MSM was too simplistic and inflexible
28
what is episodic memory?
- our ability to recall events (episodes) from our lives
- these memories are complex and time stamped
- you have to make a conscious effort to recall
29
what is semantic memory?
- shared knowledge of the world
- knowledge of concepts and are not time-stamped
- less vulnerable to distortion and forgetting
- conscious recall
30
what is procedural memory?
- memory for actions or skills
- can recall without concious effort
- hard to explain to someone else
31
strength of types of LTM - clive wearing and HM
- episodic memory in both cases was severely impacted due to brain but their semantic and procedural memory was still intact
- this evidence supports Tulving's ideas that there are different LTM memory stores
32
counterpoint for clive wearing and HM
- there is often very little control of extraneous variables due to accidents being unexpected
- there is no knowledge on the memory before the accident
- this lack of control limits what clinical studies can tell us about different types of LTM
33
limitation of types of LTM - conflicting neuro imaging research
- Randy Buckner and Steven Peterson (1996) reviewed evidence regarding the location of semantic and episodic memory
- they concluded that semantic memory is located on the left side of the prefrontal cortex and episodic memory on the right
- however different research says that the left pre frontal cortex is for episodic encoding and the right is for episodic retrieval
- this conflict challenges any neurophysical evidence
34
strength of LTM - real world application
- allows psychologists to help people with memory problems
- for example, as people age, they experience memory loss - research has shown that this is specific to episodic memory
- Belleville et al 2006 devised an intervention to improve the memory of elderly people - experiment group had better memory after training than the control group
35
what is the WMM (working memory model) (Baddeley and Hitch 1974)
an explanation of how one aspect of STM is organised and how it functions
36
what is the job of the Central executive
- has a "supervisory role"
- monitors incoming data, focuses and divides our limited attention, and allocated tasks to subsystems
- has a very limited capacity and does not store information
37
what is the job of the phonological loop?
- Processes information in terms of sound
- This includes both written and spoken material
- It's divided into the phonological store (stores the words you hear) and the articulatory process (allows maintenance rehearsal)
- Capacity of this loop is believed to be two seconds worth of what you can say
38
what is the job of the Visuo-Spatial Sketchpad?
- Processes visual and spatial information in a mental space often called our 'inner eye'
- Limited capacity according to Baddeley (2003) is about 3 or 4 objects
- Robert Logie (1995) subdivided it into the visual cache (stores visual data) and the inner scribe (records the arrangement of objects in the visual field)
39
what is the job of the Episodic Buffer?
- Brings together material from other subsystems into a single memory rather than separate strands
- Provides a bridge between working memory and long term memory
- Added by Baddeley in 2000
- A temporary store for information, integrating the stores and maintaining a sense of time sequencing - basically recording events that are happening
- Can be seen as the storage component of the central executive
- Has a limited capacity of about 4 chunks (Baddeley 2012)
- Links working memory to LTM and wider cognitive processes such as perception
40
Evaluation for WMM - Clinical Evidence (Shallice & Warrington 1970) + Counterpoint
- Study of KF who had poor STM ability for auditory information but could process visual information normally after his brain injury
- His immediate recall of letters & digits was better when he read them than when they were read to him
- His phonological loop was damaged but his visuo-spatial sketchpad was intact
- This strongly supports the existence of separate visual and acoustic memory stores
- BUT it was unclear as to whether he had other cognitive impairments which might have affected his performance on memory tasks
- This challenges evidence that comes from clinical studies of people with brain injuries that may have affected many different systems
41
Evaluation - Dual Task Performance (Baddeley et al 1975)
- Studies of dual-task performance support the existence of the visuo-spatial sketchpad
- Baddeley et al's (1975) participants carried out a visual and verbal task at the same time, their performance on each was similar to when they carried out the tasks separately
- But when both tasks were visual/verbal performance on both declined substantially
- This is because both visual tasks compete for the same subsystem (VSS), whereas there is no competition when performing a verbal and visual task together
- This shows there must be a separate subsystem (the VSS) that processes visual input (and one for verbal processing, the PL)
42
Evaluation - Nature of the Central Executive (Baddeley 2003)
- A limitation is the lack of clarity over the nature of the central executive
- Baddeley 2003 recognised this when he said 'the central executive is the most important but the least understood component of the working memory'
- The CE needs to be more clearly specified than just simply being 'attention', e.g some psychologists believe it is made up of separate components
- This means the CE is an unsatisfactory component, challenging the integrity of the WMM
43
Evaluation - Validity of the WMM Model
- These dual task and other studies use tasks that are very unlike those that we perform in our everyday lives
- They are also carried out in highly controlled lab conditions
44
what is interference?
Forgetting because one memory blocks another, causing one or both memories to be distorted or forgotten
45
what is proactive interference?
- occurs when older memories, already stored, disrupt the recall of newer memories. The degree of forgetting is greater when the memories are similar
- For example, your teacher has learned so many names in the past that they have difficulty remembering names of their current class
46
what is retroactive interference?
- occurs when newer memories disrupt the recall of older memories already stored. The degree of forgetting is greater when the memories are similar
- For example, your teacher has learned so many new names this year that they have difficulty remembering the names of students from last year
46
what is retroactive interference?
- occurs when newer memories disrupt the recall of older memories already stored. The degree of forgetting is greater when the memories are similar
- For example, your teacher has learned so many new names this year that they have difficulty remembering the names of students from last year
47
interference as an Explanation for Forgetting in LTM
- Once information has reached LTM it is more or less permanent
- Therefore, any forgetting of LTMs is most likely because we cant get access to them even though they are available
- Interference between memories makes it harder for us to locate them and this is experienced as 'forgetting'
48
McGeoch and McDonald (1931) Procedure
- Study on retroactive interference by changing the amount of similarity between two sets of materials
- Participants had to learn a list of 10 words until they could remember them with 100% accuracy
- They then learned a new list
- There were 6 groups of participants who had to learn different types of new lists:
- Group 1: synonyms - words with the same meanings as the originals
- Group 2: antonyms - words with opposite meanings to the originals
- Group 3: words unrelated to the original ones
- Group 4: consonant syllables
- Group 5: 3-digit numbers
- Group 6: No new list - these participants just rested (control condition)
49
McGeoch and McDonald (1931) Findings
- When participants were asked to recall the original list of words, the most similar material (synonyms) produced the worst recall
- This shows that interference is strongest when the memories are similar
50
Explanation on the Effects of Similarity
- Could be due to positive interference
- previously stored information makes new similar information difficult to store
- Or could be due to retroactive interference - new information overwrites previous similar memories because of the similarity
51
strength of interference- Real World Interference (Baddeley and Hitch 1977)
- There is evidence of interference effects in more everyday situations
- Baddeley and Hitch (1977) asked rugby players to recall the names of the teams they had played against in a season
- They all played for the same time interval but the number of intervening games varied because some players missed matches due to injury
- Players who played the most games (most interference of memory) had the poorest recall
- Shows that interference can operate in at least some real-world situations, increasing validity of the theory
52
Counterpoint - Real World Interference
- Interference may cause some forgetting in everyday situations but it is unusual
- This is because the conditions necessary for interference to occur are relatively rare
- This is very unlike lab studies - where high degree of control means a researcher can create ideal conditions for intereference
- For instance, two memories have to be fairly similar in order to interfere with each other
- This may happen occasionally in everyday life (e.g revising) but not often
- This suggests that forgetting may be better explained by other theories such as retrieval failure due to a lack of cues
53
limitation of interference - Interference and Cues (Tulving and Psotka 1971)
- Interference is temporary and can be overcome by using cues
- Tulving and Psotka (1971) gave participants lists of words organised into categories, one list at a time (they were not told what these categories were)
- Recall averaged about 70% of the first list but became progressively worse as participants learned each new list
- At the end of the procedure the participants were given a cued recall test and were told the names of the categories - recall rose again to about 70%
- Shows that interference causes a temporary loss of accessibility to material that is still in LTM, a finding not predicted by interference theory
54
strength of interference - Support from Drug Studies (Coenen and Luijtelaar 1997)
- Evidence from retrograde facilitation
- Coenen and Luijtelaar (1997) gave participants a list of words and then later asked them to recall it, assuming the intervening experiences would act as interference
- They found that when a list of words was learned under the influence of the drug diazepam, recall one week later was poor (compared with a placebo control group)
- But when a list was learned before the drug was taken, later recall was better than the placebo
- So the drug actually improved recall of material learned beforehand
- Wixted (2004) suggests that the drug prevents new information reaching parts of the brain involved with processing memories, so it cannot interfere retroactively with information already stored
- Shows that forgetting can be due to interference - reduce the interference and you reduce the forgetting
55
limitation of interference - Validity Issues
Evaluation - Validity Issues
- Most studies supporting interference theory are lab-based, so researchers can control variables
- Control over confounding variables also means studies show a clear link between interference and forgetting
- But these studies use artificial methods and unrealistic procedures
- In everyday life we often learn something and recall it much later
56
what is retrieval failure?
A form of forgetting. It occurs when we don't have the necessary cues to access memory. The memory is available but not accessible unless a suitable cue is provided.
57
what is encoding specific principle?
- Tulving (1983) reviewed research into retrieval failure and discovered a consistent pattern to the findings - the ESP
- This states that a helpful cue has to be present at encoding and present at retrieval
- It follows from this that if the cues available at encoding and retrieval are different (or if cue is absent at retrieval) there will be some forgetting
- Some cues are encoded at the time of learning in a meaningful way - such cues are used in many mnemonic techniques
58
what are Non-Meaningful Cues: Context-Dependent Forgetting
when recall depends on external cue (e.g place)
59
what are Non-Meaningful Cues: State-Dependent Forgetting
Recall depends on internal cue (e.g feeling upset, being drunk)
60
Context-Dependent Forgetting Research (Godden and Baddeley 1975) - Procedure
- Godden and Baddeley (1975) studied deep sea divers to see if training on land helped or hindered their work underwater
- They learnt a list of words either underwater or on land and then were asked to recall the words either underwater or on land
61
Godden & Baddeley (1975) - 4 Conditions
- Learn on land - recall on land
- Learn underwater - recall underwater
- Learn on land - recall underwater
- Learn underwater - recall on land
62
Godden and Baddeley (1975) - Findings
- In two of these conditions the environmental contexts of learning and recalling matched, whereas in others they did not
- Accurate recall was 40% lower in the non-matching conditions
- The external cues available at learning were different from the ones available at recall which led to retrieval failure
63
State-Dependent Forgetting Research (Carter & Cassaday 1998) - Procedure
- Carter & Cassaday (1998) gave antihistamine drugs to their participants
- These had a mild sedative effect which creates an internal physiological state different from the 'normal' state of being awake and alert
- Participants had to learn lists of words and passages from prose and recall the information
64
Carter and Cassaday (1998) - 4 Conditions
- Learn on drug - recall on drug
- Learn not on drug - recall not on drug
- Learn on drug - recall not on drug
- Learn not on drug - recall on drug
65
Carter and Cassaday (1998) - Findings
- In the conditions where there was a mismatch
between internal state at learning and recall, performance on the memory test was significantly worse
- So when cues are absent, there is more forgetting.
66
strength of retrieval failure - real world application
- Retrieval cues can help to overcome some forgetting n everyday life
- Although cues may not have a strong effect on forgetting, Baddeley suggests they are still worth paying attention to
- When we have trouble remembering something, it is probably worth making the effort to recall the environment in which you learned it first
- This shows how research can remind us of strategies we use in the real world to improve our recall
67
strength of retrieval failure - Research Support (Eysenck and Keane 2010)
- Impressive range of research that supports the retrieval failure explanation
- Godden & Baddeley and Carter & Cassaday are just two examples because they show that a lack of relevant cues at recall can lead to context-dependent and state-dependent forgetting in everyday life
- Eysenck and Keane (2010) argue that retrieval failure is perhaps the main reason for forgetting from LTM
- This shows that retrieval failure occurs in real life situations as well as in the highly controlled conditions of a lab
68
counterpoint of research support - Baddeley (1997)
- Argues that context effects are actually not very strong, especially in everyday life
- Different contexts have to be different indeed before an effect is seen
- E.g it would be hard to find an environment as different from land as underwater
- In contrast, learning something in one room and recalling it in another is unlikely to result in much forgetting because these environments are generally not different enough
- This means that retrieval failure due to lack of contextual cues may not actually explain everyday forgetting
69
limitation of retrieval failure - Recall vs Recognition (Godden and Baddeley 1980)
- Context effects may rely on the type of memory being tested
- Godden and Baddeley (1980) replicated their study but used a recognition test instead of recall - participants had to say whether they recognised a word from a list, instead of retrieving it themselves
- When recognition was tested there was no context-dependent effect, performance was the same in all 4 conditions
- 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
70
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. Accuracy of EWT can be affected by factors such as misleading information, leading questions and anxiety
71
what is misleading information?
incorrect information given to the eyewitness after the event (post event information) It can take many forms, such as leading questions and post-event discussion between co-witnesses and/or other people
72
Loftus & Palmer (1974) Procedure
- Arranged for 45 participants (students) to watch film clips of car accidents and then asked them questions about it
- In the critical question (a leading question) participants were asked to describe how fast the cars were travelling:
'About how fast were the cars going when they bumped/collided/hit/contacted/smashed each other?'
73
Loftus & Palmer (1974) Findings
- Mean estimated speed was calculated for each group - 'contacted' had 31.8mph and 'smashed' had 40.5mph
- The leading question biased the eyewitness' recall of an event
- the wording of the question changed how people saw the experiment
74
Loftus & Palmer (1974) 2nd Experiment
- Supported the substitution explanation which proposes that the wording of the leading question changes the participant's memory of an event
- Participants who had originally heard 'smashed' were more likely to report broken glass than those who heard 'hit'
75
Gabbert et al (2003) Procedure
- Studied participants in pairs, each watched a video of the same crime but filmed from a different pov
- Each participant could see elements in the event that the other could not e.g. the title of the book being carried by the woman
- Both participants then discussed what they had seen before individually completing a test of recall
76
Gabbert et al (2003) Findings
- 71% mistakenly recalled aspects they did not see but had picked up in the discussion, in a control group with no discussion 0% did the same
- This was evidence of memory conformity
77
strength of misleading information - Real World Application (Strength of Loftus and Palmer 1974)
-One strength of Loftus & Palmer's (1974) research is the application of their findings to the criminal justice system
- The criminal justice system relies heavily on the accounts of eyewitnesses and Loftus & Palmer's research highlights the danger of misleading information being used in the courtroom by lawyers, as a single misleading question can affect the accuracy of EWT
- This matters because psychologists can help to improve the way the legal system works, especially by protecting innocent people from faulty convictions based on unreliable EWT
78
Counterpoint - Real World Application (Foster et al 1994)
- The practical applications of EWT may be affected by issues with research
- E.g Loftus & Palmer's participants watched film clips in a lab, a very different experience from witnessing a real event (stress levels)
- Foster et al (1994) points out that what eyewitnesses remember has important consequences in the real world, but participant's responses in research do not matter in the same way (so research participants are less motivated to be accurate)
- Suggests researchers such as Loftus are too pessimistic about the effects of misleading information - EWT may be more dependable than some studies suggest
79
limitation of misleading information - Evidence Against Substitution (Sutherland & Hayne 2001)
- EWT is more accurate for some aspects of an event than others
- E.g Sutherland & Hayne (2001) showed participants a video clip and when participants were later asked misleading questions, their recall was more accurate for central details of the event than for peripheral ones
- Shows that these memories were resistant to misleading information
- Suggests that the original memories for central details survived and were not distorted, an outcome that is not predicted by the substitution explanation
80
what is anxiety?
A state of emotional and physical arousal. The emotions include having worried thoughts and feelings of tension. Physical changes include an increased heart rate and sweatiness. Anxiety is a normal reaction to stressful situations, but it can affect the accuracy and detail of EWT
81
Johnson & Scott (1976) Procedure
- Researched the weapon focus effect (reduces a witnesses' recall of other details)
- Participants believed they were taking part in a lab study
- While seated in a waiting room, participants in the low-anxiety condition heard a casual conversation in the next room and then saw a man walk past them carrying a pen with grease on his hands
- Other participants heard a heated argument, with the sound of breaking glass and a man walked out with a knife covered in blood (high-anxiety condition)
82
Johnson & Scott (1976) Findings
- Participants picked out the man from a set of 50 photos, 49% who had seen the man carrying the pen were able to identify him
- From the other group, 33% were able to identify the man with the knife
- 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
83
Yuille & Cutshall (1986) Procedure
- Studied anxiety with a positive effect on recall
- Conducted a study of an actual shooting in a gun shop in Canada - the shop owner shot a thief dead
- There were 21 witnesses - 13 took part in the study
- They were interviewed 4-5 months after and these were compared with original police interviews
- Accuracy was determined by the number of details reported in each account
- These witnesses were also asked to rate how stressed they had felt at the time of the incident (on a 7-point scale) and whether they had any emotional problems since the event (e.g sleeplessness)
84
Yuille & Cutshall (1986) Procedure
- Studied anxiety with a positive effect on recall
- Conducted a study of an actual shooting in a gun shop in Canada - the shop owner shot a thief dead
- There were 21 witnesses - 13 took part in the study
- They were interviewed 4-5 months after and these were compared with original police interviews
- Accuracy was determined by the number of details reported in each account
- These witnesses were also asked to rate how stressed they had felt at the time of the incident (on a 7-point scale) and whether they had any emotional problems since the event (e.g sleeplessness)
85
Yuille & Cutshall (1986) Findings
- Witnesses were very accurate in their accounts and there was little change in the amount recalled or accuracy after 5 months - Though some details were less accurate, such as recollection of the colour of items and age/height/weight estimates
- Participants who reported the highest levels of stress were most accurate (88% compared to 75% for the less-stressed group)
- Suggests that anxiety does not have a detrimental effect on the accuracy of eyewitness memory in a real-world context and may even enhance it
86
why were there contradicting results between the two studies
- Yerkes & Dodson (1908) suggested the relationship between emotional arousal and performance looks like an 'inverted U'
- Deffenbacher (1983) reviewed 21 studies of EWT and noted contradictory findings on the effects of anxiety
- Used the Yerkes-Dodson law to explain the findings:
- When we witness a crime/accident we become emotionally and physiologically aroused
- We experience anxiety (emotional) and physiological changes (fight or flight)
- Lower levels of anxiety/arousal produce lower levels of recall accuracy, and then memory becomes more accurate as the level of anxiety/arousal increases
- However, there is an optimal level of anxiety, which is the point of maximum accuracy
- If a person (or eyewitness) experiences any more arousal, then their recall suffers a drastic decline
87
why were there contradicting results between the two studies
- When we witness a crime/accident we become emotionally and physiologically aroused
- We experience anxiety (emotional) and physiological changes (fight or flight)
- Lower levels of anxiety/arousal produce lower levels of recall accuracy, and then memory becomes more accurate as the level of anxiety/arousal increases
- However, there is an optimal level of anxiety, which is the point of maximum accuracy
- If a person (or eyewitness) experiences any more arousal, then their recall suffers a drastic decline
88
limitation of anxiety and EWT : Unusualness not Anxiety (Limitation of Johnson and Scott 1976) (Pickel 1998)
- They may not have tested anxiety
- The reason for weapon focus may be because they were surprised at what they saw rather than scared
- Pickel (1998) conducted an experiment using scissors, a handgun, a wallet or a raw chicken as the handheld items in a hairdressing salon video (scissors would be high anxiety, low unusualness)
- Eyewitness accuracy was significantly poorer in the high unusualness conditions (chicken and handgun)
- Suggests that the weapon focus effect is due to unusualness rather than anxiety/threat and therefore tells us nothing specifically about the affects of anxiety on EWT
89
strength of anxiety and EWT: Support for Negative Effects (Valentine & Mesout 2009)
- Evidence supporting the view that anxiety has a negative affect on the accuracy of recall
- Valentine & Mesout (2009) supports research on weapon focus, finding negative effects on recall
- The researchers used an objective measure (heart rate) to divide participants into high and low-anxiety groups
- Anxiety clearly disrupted the participant's ability to recall details about the actor in the London Dungeon's Labyrinth
- Suggests that high level of anxiety does have a negative effect on the immediate eyewitness recall of a stressful event
90
strength of anxiety and EWT: Support for Positive Effects (Christianson & Hubinette 1993)
- Christianson & Hubinette (1993) interviewed 58 witnesses to bank robberies in Sweden, some were directly involved (workers) and some indirectly (bypassers)
- Researchers assumed that those directly involved would experience the most anxiety
- It was found that recall was more than 75% accurate across all witnesses, the direct victims (most anxious) were even more accurate
- These findings from actual crimes confirm that anxiety does not reduce the accuracy of recall for eyewitnesses and may even enhance it
91
counterpoint for Support for Positive Effects (Christianson & Hubinette 1993)
- Christianson & Hubinette interviewed their pafrticpants several months after the event (4-15 months)
- So, they had no control over what happened to the participants in their interviewing time (e.g post-event discussions)
- The effects of anxiety may have been overwhelmed by these other factors and impossible to assess by the time the participants were interviewed
- So, a lack of control over confounding variables may be responsible for the findings, invalidating their support
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what are the most important parts of cognitive interviews?
1. report everything
2. reinstate the context
3. reverse the order
4. change perspective
