2. Memory Specification
• The multi-store model of memory: sensory register, short-term memory and
long-term memory. Features of each store: coding, capacity and duration.
• Types of long-term memory: episodic, semantic, procedural.
• The working memory model: central executive, phonological loop, visuo-spatial
sketchpad and episodic buffer. Features of the model: coding and capacity.
• Explanations for forgetting: proactive and retroactive interference and retrieval
failure due to absence of cues.
• Factors affecting the accuracy of eyewitness testimony: misleading information,
including leading questions and post-event discussion; anxiety.
• Improving the accuracy of eyewitness testimony, including the use of the
cognitive interview
3. Coding, Capacity, and Duration of Memory
• Baddeley – coding in STM and LTM
• Acoustically similar words (cat, cab) were worse recalled immediately and semantically similar words were recalled better long term.
• STM is acoustic and LTM is semantic (because its similar words were getting confused so the store must be related to getting confused).
• Low ecological validity – words have no meaning to the person, lacks mundane realism.
• Jacobs – capacity of STM
• Researcher increases digits read until can be repeated back. 9.3 numbers avrg.
• Digit span = 9.3
• Conducted long lime ago – less control of extraneous variables – validity.
• Miller – capacity of STM
• Notices things come in 7s
• Span of STM is 7+/-2 but can be improved by chunking.
• Reviewed research shows that capacity is 4 chunks, number should be 5 not 7.
• Peterson and Peterson – duration of STM
• Given 3 consonants and 3 numbers to remember, count down from different numbers to test duration without rehearsal. After 18 secs
recall dropped to 3%.
• Duration of STM = 18-30 secs
• Memorising numbers and letters doesn’t reflect real life – low ecological validity, lacks mundane realism.
• Bahrick et al. – duration of LTM
• Recognise photos – those tested 48 years after graduation were 70% accurate
• Real life meaningful memories so high ecological validity.
• Suffered confounding variables as participants may have reviewed year books multiple times.
4. Multi-store Model of Memory- Atkinson &
Shiffrin
• Sensory register (where info from senses are held, if it receives no attention it only remains for a brief duration)
1. Coding = depends on sense
2. Capacity = high
3. Duration = brief < ½second
• STM
1. Coding = acoustic
2. Capacity = 5-9 items (7-2or+2)
3. Duration = 18-30 seconds
• LTM
1. Coding = semantic
2. Capacity = unlimited
3. Duration = indefinite
• Idea of independent separate stores supported by Baddeley's research.
• Glanzer & Cunitiz – ‘Serial position effect’ shows rehearsal brings first few into LTM and last few were kept in STM (word list).
• Artificial materials – real life not words
• HM – separate stores as could remember old memories but couldn’t make new ones (after operation to remove parts to stop epileptic fits).
• KF – suffered brain damage after motorbike accident. Had good memory when recalling written digits, bad when digits read out loud. This suggests there are
two types of STM – auditory and visual
• Rare group means low generalisability.
• Only explains one type of rehearsal (maintenance not elaborate) – elaborate is needed for long term storage which involves linking to pre-existing
information.
• Oversimplifies LTM – lots of evidence of it being multi-stores.
Sensory
register
5. Types of Memory
• Types of memory:
1. Episodic (episodes) – recall of events, time stamped conscious effort to recall them e.g.
dinner yesterday
2. Procedural (procedures) – memory of actions and skills, unconscious so hard to explain
e.g. writing
3. Semantic – knowledge of the world and facts, not time stamped e.g. word definitions
• Tuvling – PET scans shows different brain areas active during different memory
tasks.
• May be evidence that conscious memories are one store themselves.
• HM & Clive Wearing – episodic memory impaired due to amnesia, semantic and
procedural still in tact.
• Evidence based on brain damaged participants is difficult to make generalisations from as
there is a lack of control and there could be unknown confounding variables.
• Led to treatment – episodic memories in older people can be improved with mild
cognitive impairments.
6. Working Memory Model –
Baddeley & Hitch
• Model of just STM
• Central executive – drives the system, decides how attention is allocated, no storage capacity.
• Central executive is unsatisfactory and doesn’t explain anything – most important least understood.
• Scanning studies show evidence for.
• Visuo-spatial sketchpad – holds visual and spatial info for short time. Further divided into the
visual cache (stores visual data) and inner scribe (records object arangement).
• Baddeley and Hitch – can’t do maze while describing letter F but can while singing a song so must be one store.
Multitasking cant be explained by multi-store model of memory.
• Phonological loop – deals with auditory info. Further divided into the phonological store (stores
words you hear) and articulatory process (silently repeated words read or heard).
• Baddeley found its more difficult to remember list of long words – supports limited space fro rehearsal in
articulatory process.
• Episodic buffer – added later and maintains a sense of time sequencing (episodes) and integrates
information from other stores.
• KF – had difficulty with sound but could recall written digits and letters (separate visual
and acoustic stores) after motorbike crash left him brain damaged.
• generalisability
7. Explanations for forgetting
• Interference Theory:
• Retroactive interference – when newer memories disrupt recall of older memories (getting a new number and forgetting your old one)
• Proactive interference – when older memories disrupt recall of newer ones. (saying you are 17 when you just turned 18)
• Interference is worse when memories are similar.
• McGeach & McDonald - Participants learnt one list of words off by heart, the more similar the second list made the recall worse.
• Consistently demonstrated by lab studies.
• Uses artificial materials and a short period of time (lacks mundane realism)
• High face validity – see it in everyday life
• May be overcome by cues – when unable to remember word list thought to be due to interference giving a cue overcomes.
• Retrieval Failure:
• Encoding specificity principle - If a cue is to help, it must be present at encoding and retrieval.
• Some cues are linked to the meaning and others are not:
• Context dependent forgetting and state dependent forgetting
• Baddeley – accurate recall was 40% lower in non-matching conditions (learning and recalling water/land)
• Carter & Cassaday – state dependent forgetting (learning and recalling on/off antihistamine – performance was worse when there was mismatch
• Real life application – cognitive interview uses mental reinstatement / revising in the room you do the exam in
• Unlikely to work as well in real life as contexts aren’t different enough like underwater and on land.
• Lots of evidence to support
• Participant variables and demand characteristics
• Only occurs when memory is tested in certain ways e.g. retrieval not recognition.
• Retrieval cues don’t always work?
• No way to really establish if a cue has been encoded or they are just remembering correctly
8. Eyewitness Testimony
• Leading questions, post-event discussion, anxiety
• Loftus and Palmer
1. Speed of car when different verbs were used in questions (smashed, collided, bumped, hit, contacted) 10mph difference between smashed and
contacted. 5 independent groups.
2. “was there broken glass” when verbs were smashed, hit, *control*. Higher percent of people said yes when smashed.
3. 2 weeks later another group were asked if they saw broken glass, this shows that it is not just due to a response-bias because leading questions actually
altered the memory. Misleading info has deleted the true memory.
• Real life application – officers need to be careful with leading questions, lead to cognitive interview.
• Artificial – watched video clips so no emotion or anxiety – lacks external validity.
• Demand characteristics - unlikely
• Asking uni students speed, subjective as continuous spectrum anyway. Also low generasibality.
• Study watching different videos - post event discussion lead to 71% recalling things they didn’t see, in the control it was 0%.
• Due to memory contamination and memory conformity.
• Own-age bias – more likely to conform to majority if others are of the same age.
• Johnson & Scott -Low anxiety condition (overhears argument, man walks out with pen) – 49% recognised him. High anxiety condition
(overhears argument, man walks out with knife) – 33% recognised him.
• Deception & consent & psychological harm
• Contradictory evidence
• Extraneous variables
• May test surprise not anxiety (surprise that the person is carrying a knife)
• Another study showed that the more stressed the participants the better the recall – real life shooting.
• Bell shaped curve on anxieties effect (inverted U theory). Deffenbacher – there is an optimum level of anxiety.
• To simplistic as anxiety cant be properly measured.
9. Cognitive Interview
• Fisher reviewed interviews and found eyewitnesses were not allowed to talk freely, broke
concentration, and were encouraged to give short answers with less detail. He later developed
the enhanced CI which focuses on social dynamics like eyecontact.
• Four principles to improve accurate recall:
1. Report everything – even if irrelevant
2. Mental reinstatement of original context – return to crime scene mentally
3. Changing to order – prevents reporting expectations
4. Changing the perspective – prevent generating expectations
• Time consuming
• Some principles are found as more important than others.
• Only two needed to be taught (report everything,
context reinstatement) – cheaper and easier.
• Meta-analysis shows more correct info if CI.
• Research is unreliable due to slightly different techniques of CI.
• Leads to more correct memories but also more incorrect memories.