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
Capacity
The amount of information that can be stored in memory.
Duration
How long a memory trace can last.
Coding
The form in which a memory trace is created.
MSM components
- Sensory store
- Short term memory (working memory)
- Long term memory
MSM - Sensory store
- Senses pick up information (visual, auditory, haptic)
- Capacity = huge
- Duration = short (1-2 seconds)
MSM - Short term memory
- Capacity = 7+/- 2 items
- Duration = 18-30 seconds
- Encoding = acoustic
- Information will decay if it isn’t rehearsed, or if new information enters STM and pushes out the original information due to STM’s limited capacity (displacement).
MSM - Long term memory
- Capacity = infinite
- Duration = infinite / lifetime
- Encoding = semantically
- Information is moved from STM to LTM via maintenance rehearsal.
- Initially rehearsal just maintains the information in STM but the more something is rehearsed the longer the lasting memory will be.
- Elaborate rehearsal can increase memory if linked to stories.
Working memory model - features
- Central executive
- Visuospatial sketchpad
- Episodic buffer
- Phonological loop
- Long term memory
WMM - Central executive
- Directs attention to tasks - decides what working memory pays attention to.
- Controls the ‘slave systems’ - other 3 components.
- Data arrives from the senses or from LTM.
- Limited capacity.
WMM - Phonological loop
- Limited capacity - holds 2 seconds worth of info.
- Auditory information
- Codes acoustically
- Phonological store (holds words heard) - inner ear
- Articulatory process / loop (holds words heard / seen and silently repeated) - inner voice
WMM - Visuospatial sketchpad
- Visual and/or spatial information stored here
- Limited capacity
- Visual cache (stores information about visual items)
- Inner scribe (for spatial relations which stores the arrangement of objects)
WMM - Episodic buffer
- Buffer extra storage system but with limited capacity
- Integrates information from all other areas
- Maintains a sense of time sequencing
Dual task paradigm
- If you try and do 2 verbal tasks at the same time, performance is poor.
- You can perform two tasks at the same time, as long as you are using two different components of the working memory model.
Endel Tulving (1967) - 3 types of LTM
- Epsiodic memory
- Semantic memory
- Procedural memory
Episodic memory (x3)
- Involves conscious thought and is declarative
- 3 specific elements: details of the event, the event, the emotion
- Associated with the hippocampus and right prefrontal cortex (Tulving 1994)
Semantic memory (x4)
- Meaning of words and general knowledge
- Involves conscious thought and is declarative
- Often start as episodic memories but they are not time stamped (they do not remain associated with an event)
- Associated with the left prefrontal cortex (Tulving 1994)
Procedural memory (x3)
- Knowledge of how to do things / carry out complex tasks
- It does not involve conscious thought and is non-declarative
- Associated with the cerebellum and motor cortex
Declarative
Knowing that
Non-declarative
Knowing how
Interference (x2)
- When 2 pieces of information conflict with each other
- This can result in forgetting one or both pieces of information, or a distortion of memory
Retroactive interference
When a newer memory interferes with an older one.
Proactive interference
Occurs when an older memory interferes with a newer one.
Context dependent forgetting
External environmental cues
State dependent forgetting
Internal cues
Retrieval failure
Forgetting due to a lack of cues
Encoding specificity principle
Tulving: cues most effective if present at coding and at retrieval.
