Memory Flashcards
Eyewitness
Someone who has seen or witnessed a crime, usually present at the time of the incident.
Eyewitness testimony
The evidence provided in court by a person who witnessed a crime, with a view to identifying the perpetrator.
Loftus and Palmer (1974) - Speed estimates according to verbs used (leading questions) (x4)
- 45 student participants shown short films involving car accidents
- Critical question = estimate the speed of the cars
- Verbs varied: ‘hit’, ‘smashed’, ‘bumped’, ‘contacted’
- The more ‘extreme’ the verb was in the question, the higher the average estimation of the cars’ travelling speeds
Gabbert et al (2003) - Post-event discussion (x5)
- 60 students and 60 older adults
- Watched a video of a girl stealing money from a wallet (each group watched different perspectives)
- Control group = tested individually, Co-witness group = tested in pairs
- Co-witness group: 71% recalled information they had not seen, 60% said the girl was guilty (even though they had not seen her commit a crime)
- Highlights the issue of post-event discussion and the effect of this on the accuracy of EWT
Pickel (1998) - Is threat or unusualness the cause of weapon focus?
Man walking into a hair salon holding: (recall)
- Scissors (8.14)
- Handgun (7.83)
- Wallet (8.53)
- Raw chicken (7.21)
- Empty (9.02)
The handgun and raw chicken resulted in the lowest recall and therefore unusualness rather than anxiety / threat may explain the ‘weapon focus’.
Yuille and Cutshall (1986) - Can anxiety have a positive effect? (x5)
- Studied a real-life shooting in a gun shop in Canada
- The shop owner shot a thief dead
- Little change in EWT after 5 months
- Participants who reported high levels of stress were most accurate (88% compared to 75% for the less-stressed group)
- Anxiety has a positive effect - leading questions have little effect
Yerkes-Dodson law - Inverted U theory
- Performance will increase with stress, but only to a certain point, where it decreases drastically.
- Supported by Deffenbacher (1983)
Anxiety (x2)
- An unpleasant emotional state where we fear something bad is about to happen.
- One argument is that anxiety creates physiological arousal in the body which prevents us paying attention to important cues so recall is worse.
Weapon focus
Looking at the effect of weapons (which create anxiety) on accuracy of recall of the witness.
Effect of weapon focus
In violent crimes, arousal may focus the witness on more central details of the attack (e.g weapon) than the more peripheral details (e.g what else was going on and what the perpetrator looked like).
Johnson and Scott (1976) - Anxiety has a negative effect on EWT (x5)
- Whilst seated in a waiting room, participants heard an argument in the next room.
- In the low-anxiety condition a man walked through the waiting area carrying a pen with grease on his hands.
-In the high-anxiety condition the argument was accompanied by the sound of breaking glass, and a man walked out of the room holding a paper knife that was covered in blood. - 49% of the low-anxiety condition correctly identified the man, whereas only 33% did in the high-anxiety condition.
- The tunnel theory of memory argues that a witness’ attention narrows to focus on a weapon because it is a source of anxiety.
Components of the cognitive interview - Fisher and Geiselman (1992)
- Report everything
- Reinstate the context
- Reverse the order
- Change perspective
Cognitive interview - Report everything
- Saying everything that you saw
- Memories act as cues to trigger other memories
Cognitive interview - Reinstate the context
- Going back mentally to the event
- Prevents context-dependent forgetting
Cognitive interview - Reverse the order
- Chronological shift (e.g recalling in reverse order)
- Prevents schemas from filling gaps in memory
Cognitive interview - Change perspective
- Recalling information from someone else’s perspective
- Disrupts the effect of expectations and schemas on recall
