Memory Part 2 Flashcards
Two explanations for forgetting
- Interference (proactive/retroactive)
- Retrieval failure due to absence of cues
When is interference more likely
When memories are similar
Proactive interference
When an old memory interferes with the recall of a new memory
Retroactive interference
When a new memory interferes with the recall of an old memory
How does proactive interference cause forgetting
It makes new information harder to store
How does retroactive interference cause forgetting
Previous memories are overwritten if they are similar
McGeoch and McDonald Study
- Six groups of pps
- Learn a list till 100% accurate
- 5/6 groups had to learn a new list
- Had to recall the original list
McGeoch and McDonald study list types
IN ORDER OF WORST TO BEST RECALL
- Synonyms
- Antonyms
- Unrelated adjectives
- Nonsense syllables
- Numbers
- (No new list, control group)
McDonald and McGeoch strengths
- Lab study
- Well-controlled
- Extraneous variables are minimised
Baddeley and Hitch (1977)
- Sample of rugby players who had played every match, and who had missed some due to injury
- Players who played more games forgot more games
- Equal accuracy in recalling previous team played regardless of time
- Retroactive interference
Schmidt et al (2000)
- 211 dutch pps
- age range 11-79
- Given a questionnaire with a streetmap of the Molenburg neighbourhood
- Had to remember as many steetnames as possible
- The more people had moved outside of Molenburg, the more street names were forgotten due to retroactive intereference
Weaknesses of interference theory
- evidence is mostly from lab studies
- lab studies use unrealistic material and therefore lack ecological validity
- lab studies have short time periods between learning and recall, which may exaggerate effects
- interference can be overcome using cues
- Tulving and Psotka gave 5 lists of 24 words in different categories
- 70% accuracy on first list and reduces as it goes on
- accuracy went back to 70% when reminded of category
Retrieval failure due to absence of cues
The memory is present, but cannot be retrieved due to absence of cues
Encoding specificity principle (Tulving)
Retrieval is easier when the same cues from encoding are present
Types of cues (ESP)
Meaningfully linked cues
Non-meaningfully linked cues: External and Internal
External cues are context dependent (environment)
Internal cues state dependent (mental state)
Tulving and Pearlstone (1966)
- Got pps to recall 48 words among 12 categories
- Category was given before the word was mentioned
- When the cue was present, recall was 60%
- When not present, 40%
Types of retrieval faliure
Context dependent
State dependent
Abernthy (1940)
- Tested students in different groups on a course they were doing
- Same room, same instructor (best results)
- Different instructor, same room
- Different room, same instructor
- Different room, different instructor (worst results)
- More ‘able’ students were less affected
Godden and Baddeley (1975)
- 18 divers were asked to learn lists of 36 words
Conditions (best to worst): - Learn on the beach, recall on the beach
- Learn underwater, recall underwater
- Learn on the beach, recall underwater
- Learn underwater, recall underwater
Context dependent retrieval failure evaluation
- Effects may not be as strong in real life, as context differences are smaller than in Godden and Baddeley experiment
- Abernerthy’s study showed that it does apply in real life contexts
- In Godden and Baddeley’s experiement, there was no effect on recognising the words rather than aving to free recall
State-dependent retrieval faliure
Retrieval failure can happen when state of mind is different at learning and recall was
Carter and Cassaday
- Learn words and information passages either on anti-histamines or not
- Recall was either with or without drug (4 groups)
- Results were best when internal state matched
State-Dependant Retrieval failure evaluation
- Range of research for both state and context dependencies
- Goodwin et al: Learning words while drunk, recall drunk or sober 24 hours later
- Has real life application (Cognitive Interview), remember your internal state
- Word list tasks lack ecological validity
- You cant tell which cues are actually meaningful, can’t analyse people’s minds
What can affect Eyewitness Testimony (EWT) accuracy?
Leading questions and post-event discussion
What is a leading question?
A question that suggests what answer is desired because of its phrasing
Loftus and Palmer (1974)
- Showed 45 students a car accident
- Asked how fast the car where doing when they ‘hit’ each other
- Changed the verb ‘hit’ to ‘smashed’, ‘bumped’, ‘collided’, ‘contacted’
- ‘contacted’ gave average speed estimate of 31.8mph, and ‘smashed’ gave average speed estimate of 40.5mph
How do leading questions affect EWT?
It does not affect memories, but only influences how they choose to answer (response-bias explaination)
However a second experiment by Loftus and Palmer showed that those who used the verb ‘smashed’ reported broken glass when there was none (substitution explanation)
Loftus and Zanni (1975)
- Shown a car accident
- Asked if they saw ‘a’ broken headlight or ‘the’ broken headlight
- Condition 1: 7% reported
- Condition 2: 17% reported
- Supports the substitution explanation
Post Event Discussion
- Co-witnesses to a crime experience the event differently
- Memory contamination can occur by mixing the different accounts
- People show conformity and go along with what others say
Gabbert et al (2003)
- 60 students, university of Aberdeen
- 60 older adults
- Watched a video of a girl stealing money from a wallet
- Tested individually or in pairs
- Told they saw the same video (only one actually saw her steal)
- 71% of pps who were tested in pairs reported information they didn’t see
- 60% said the girl was guilty even if they didn’t see the crime
EWT strengths
- Lab studies are easy to control
- Lab studies are easily repeated
- Important real-life application
- Helped police to not ask leading questions, and avoid witnesses discussing
- Bodner et al (2009), effects of post event discussion can be reduced by warning witnesses about it
EWT weaknesses
- Watching videos is different from real experiences
- Less anxiety
- pps may not feel motivated as there are no serious consequences
- Risks demand characteristics
- Participants in Loftus’ experiments were all students, low population validity
Yuille and Cutshall (1986)
- Natural experiment (high ecological validity)
- 13 witnesses of a real crime (armed robbery in Canada)
- Traumatic (shop owner shot the thief dead)
- Interviewed 5 months later
- Asked two leading questions: had no effect
- Those who reported higher stress were 88% accurate, those who reported lower stress were 75% accurate
Yerkes-Dodson law
Performance increases with stress, but only to a certain point, after which it drops off
Deffenbacher (1983)
- Reviewed 21 studies linking stress to EWT accuracy
- 10 showed higher stress increased EWT accuracy
- 11 showed the opposite
- Memory recall is best at an optimum level of anxiety
Loftus and Burns
- pps either watch a boy get shot in the head (violent) or a non-violent crime
- pps who watched the violent video showed less accuracy
Weapon focus effect
Witnesses will focus on the weapon out of fear, causing them to miss out on key details other than the weapon
Johnson and Scott
Participants sat outside a lab and heard one of two situations:
1) A friendly conversation followed by a man emerging carrying a pen with grease on his hands (low anxiety)
2) An argument with smashing glass and overturned furniture followed by a man emerging with a blood stained knife
- 49% accuracy identifying man with pen
- 33% accuracy with the knife
Christianson and Hubinette
- Natural experiment
- 58 real witnesses to a bank robbery in Sweden
- General accuracy was 75%
- Highest accuracy was from victims, who had highest anxiety
Pickel (1998)
- Suggests weapon focus effect was due to surprise more than anxiety
- Thief enters hair salon with either scissors (high threat, low surprise), handgun (high threat, high surprise), wallet (low threat, low surprise) or whole raw chicken (low threat, high surprise)
- Weapon focus effect is due to unusualness rather than anxiety
Anxiety effect on EWT weakness
- Field studies have a lack on control, as the more anxious participants were likely closer to the crime and got to see more details
- Ethical issues with causing stressful situations on participants
- Anxiety is hard to measure
- Bothwell et al found that Neurotic (highly anxious) people were less accurate as stress increased, whereas stable individuals were more accurate with higher stress
- May not affect everyone in the same way
Who originally developed the cognitive interview
Geiselman et al
Problem with standard police interviews
Brief, direct, closed questions
Witnesses can be interrupted
Leading questions
Cognitive Interview Principles
1) Context Reinstatement
Remembering the physical and psychological context of the incident, and being asked to recall it to make use of state-dependent and context-dependent recall
2) Report everything
Encourage the reporting of everything, even insignificant details. Interruption is avoided. Allowed for small details from many witnesses to form a larger picture, or for memories to get triggered
3) Recall in changed order
Trying to recall the event in a different timelines, as recollections are influenced by schema, and your general expectations of a situation may be influenced in normal order
4) Recall from a different perspective
Imagine how it would have appeared to other witnesses to prevent the effect of schemas
Gieselman et al (1986)
- Staged situation of an intruder with a BLUE RUCKSACK stealing a slide projector from a classroom
- pps asked a misleading question “was the guy with the GREEN BACKPACK nervous?”
- Interviewed under standard police interview and cognitive interview
- Cognitive interview pps were less likely to recall the rucksack as being green
Cognitive Interview weaknesses
- Time consuming, these interviews take longer
- Interviewer needs a lot of training: Memon et al reported that experienced detectives with little (4 hours) of CI training did not generate much more information
- CI studies on EWT are normally done in labs, which may not generalise, and there is less stress
- CI is less effective on children under the age of 8, likely due to them not being able to understand the instructions.
