Coding, capacity, duration
AO1
Coding STM & LTM: Baddeley (1966) Encoding is acoustic in STM & semantic in LTM
Capacity STM: Jacobs (1887) digit span task, 9.3 numbers, 7.3 letters and Miller's (1956) Magic Number 7+/- 2 items
Duration: STM Peterson & Peterson (1959) Trigrams 80% at 3s / 3% at 18s LTM Bahrick (1975) 70% 48 years
AO3
+/- Internal & ecological validity
- Size of the chunk not specified
- Individual differences (age)
- Miller overestimated capacity - closer to 4 (Cowan, 2001)
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Working Memory
Model
AO1
Model to explain STM only
Central executive - supervisory role, attention, decisions, very limited capacity
Slave systems:
PL - phonological store (inner ear) / articulatory process (inner voice): holds 2 secs worth of info
VSS - visual cache (store) / inner scribe (spatial tasks): 4 objects
Episodic buffer - temporary,
allows for integration
AO3
+ Evidence from KF (VSS intact, PL damaged)
+ Dual task studies - Baddeley, 1975
- CE least understood
- Evidence lacks mundane realism
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Eye witness testimony:
Misleading info
AO1
Leading questions
Loftus & Palmer (1974) contacted 31.8mph, smashed 40.5mph
Response bias or substitution?
Broken glass follow up = substitution more likely
Post event discussion
Gabbert (2003) 71% of the co-witness group reported info not seen & 60% of the ppts who had not seen her steal wrongly accused her of theft
Memory contamination or memory conformity
AO3
+ Real world application to criminal justice system
- Studies: low ecologically validity
- Higher recall in field experiment, Yuille & Cutshall (1986)
- Individual differences - age bias
Multi Store Model
of Memory
AO1
First ever model of memory
Atkinson & Shiffrin (1968)
Linear, sequential model
Suggests there are 3 separate & distinct memory stores
SS - modality specific, less 1/2 second and large capacity
STM - acoustic, 18-30 secs, 7+/-2
LTM - Semantic, infinite, unlimited
SS->STM attention
STM->LTM maintenance rehearsal
AO3
+ HM - more than one store
+ Very influential model
- Over emphasis of rehearsal (elaborative needed)
- KF more than one STM​​
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Forgetting:
Interference
AO1
When two memories disrupt
Proactive - old memory affects new memory
Retroactive - new memory affects old memory
Effects of similarity: more similar = more interference
McGeoch & McDonald (1931) - synonyms 12% and numbers 37%
Effects of time: shorter time = more interference
AO3
+ Baddeley & Hitch - Rugby study - Interference not time
- Studies lack ecological validity
+ Individual differences - greater WM, less susceptible
- Memories need to be very similar
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Eye witness testimony:
Anxiety
AO1
Anxiety: negative effect
Johnson & Scott (1976) Waiting room, pen knife study: 49% low anxiety, 33% high anxiety (weapon focus effect)
Anxiety: positive effect
Yuille & Cutshall (1986) Gun shop shooting in Canada
High anxiety 88%, low anxiety 75%
Yerkes-Dodson (1908) curve: inverted U theory can explain contradictory findings
AO3
+ Pickel (1998) Measuring surprise rather than anxiety?
- Y&C: confounding variables
- Individual differences: stables v neurotics
- U theory is too reductionist in only anxiety = arousal​
Types of
LTM
AO1
Tulving (1972) 3 types of LTM:
Episodic - personal events, time stamped, declarative (conscious recall)
Semantic - knowledge, not time stamped, declarative (conscious recall)
Procedural - motor skills, not time stamped, non-declarative (conscious recall)
AO3
+ HM - more than one LTM
+ Brain scans - episodic (right frontal) semantic (left frontal)
+ Real life application for helping with dementia
- Cohen & Squire: Only two stores declarative v non-declarative - not parsimonious​​​
Forgetting:
Retrieval Failure
AO1
Forgetting due to absence of cues
Encoding specificity principle
Context dependent forgetting
Godden & Baddeley (1975) -
Diver Study
State dependent forgetting
Carter & Cassaday (1998) -
Antihistamine study
AO3
+ Real world application
- Studies: ecologically validity
- Cannot test ESP as do not know if cue was encoded or not
- Results not replicated for a recognition task​​
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Eye witness testimony:
Cognitive interview
AO1
Fisher & Geiselman (1992)
Report everything (cues)
Reinstate context (context dependent forgetting)
Reverse the order (schemas)
Change perspective (schemas)
Enhanced CI - social elements
AO3
+ Kohnken (1999) meta analysis - 41% more accurate
- Report everything and reinstate context most important
- Time consuming and training
- Individual differences: Wright and Holliday (2007) more effective when respondents are older
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