psychology - memory

Multi-Store Model

Represents how memory works using sensory register, short term memory and long term memory

Developed by Atkinson and Schiffrin

Sensory Register

• Encoding - modal specific

• Capacity - high

• Duration - ½ or ¼ of a second

Short Term Memory

• Encoding - acoustic

• Capacity - 7 ± 2

• Duration - 18-30 seconds

Long Term Memory

• Encoding - semantic

• Capacity - unlimited

• Duration - permanent

Encoding Definition

The way in which information is stored in the memory stores

How is information passed from sensory register to STM

Information is passed if you pay attention to it

How is information held in STM

Maintenance rehearsal ; if it is rehearsed long enough, info is passed to LTM

Study of Capacity of STM

Miller (Immediate Digit Span Test)
Jacobs Support

Strength of capacity of STM research

• Jacob tested STM by reading aloud 4 digits and increasing the amount each time. This was stopped when ppt recalled number sequence incorrectly - average was 9.3 digits

• ✅RESEARCH SUPPORT - as other researchers found support for his findings e.g. Miller, increasing validity + Jacob’s study was old so newer psychologists confirmed his results after controlling confounding variables, increasing reliability

Limitation of research into capacity of STM

• Capacity was overestimated

• Miller found that ppt could recall 5-9 chunks of information whereas there was conflicting research as Cowan(2001) found ppt could only recall 4

Study of Duration of STM

• Peterson and Peterson tested 24 students memory by having them recall trigrams after doing a distraction test so they couldn’t use maintenance rehearsal to recall information

• Found STM duration without rehearsal is up to 18 seconds

AO3 of research into duration of STM

• Peterson and Peterson used artificial stimuli as they asked ppt to recall meaningless trigrams with is not representative of everyday life, ↓ ecological validity due to low mundane realism

• Research support - after distraction test, ppt couldn’t recall trigram as recall was only 3% after 18s, showing STM has short duration

Study of encoding into STM and LTM

• Baddeley asked ppt to recall semantically similar & dissimilar words and acoustically similar and dissimilar words.

• He found that we encode acoustically for STM and semantically for LTM

Strength of research of encoding into STM/LTM

• Baddeley’s research identifies two clear and distinct memory stores which led to the development of the multi store model of memory, ↑ construct validity

Limitation of encoding into STM/LTM

• Baddeley’s research uses artificial stimuli as ppt recalled random words which were not representative of everyday life, ↓ ecological validity due to low mundane realism

Study of duration into LTM

Bahrick et al conducted a natural experiment where he asked 394 ppt aged 17-74 to identify photos of their high school peers 15 and 48 years after graduation

15 years - there was 90% accuracy

48 years - there was 60% accuracy

Strength of research into duration of LTM

• high external validity- e.g. Bahrick used information that was applicable to real life e.g. recognising faces, so there’s high mundane realism ∴ ↑ ecological validity

Limitations of research into duration of LTM

• Confounding variable - ppt may have stayed in contact with their classmates which affects their memory which affects study, decreasing internal validity

Strength of Multi-Store Model of Memory

• Research support for STM and LTM being different stores

• Evidence → participants were told to recall semantic and acoustically similar words

• Baddeley found STM encodes acoustically and LTM encodes semantically

• Counter → his study used artificial stimuli meaning MSM may not be a valid model of how memory works in the real world

Limitations of MSM

• Evidence to support multiple STM stores, not represented by MSM

• Evidence to support prolonged rehearsal is not needed for info to be passed from STM to LTM, but elaborative rehearsal (linking info to existing knowledge) → MSM doesn’t fully show how LTM is achieved

• MSM is outdated - simplifies LTM so ignores complexity of the store, reducing explanatory power and usefulness, ↓ construct validity

Types of LTM

• Procedural → memory for actions and skills (non-declarative, most resistant to forgetting, associated with motor cortex)

• Episodic → ability to recall events in life (time stamped, declarative, easiest to forget, associated with prefrontal cortex)

• Semantic → contains general knowledge (declarative, resistant to forgetting, associated brain region is parahippocampal)

AO3 for types of LTM

• ✅research support for different types of LTM → Clive Wearing had difficulty recalling memories that happened to him in the past but could play the piano (episodic was affected, procedural was fine)

• ✅RWA - memory therapy for old people (for episodic) → therapy improved their episodic LTM compared to a control group, distinguishing distinct stores enables effective treatment

• ❌conflicting neuroimaging findings → there is poor agreement where LTM stores are located, e.g. whether semantic is in right or left prefrontal cortex

• ❌conflicting research suggests there are 2 types of LTM rather than 3 since episodic and semantic are declarative and should be classed as one

What is retrieval failure

What are cues

• retrieval failure → type of forgetting where cues at encoding are absent at recall so memory can’t be accessed

• cues → a trigger that helps access a memory

what is the encoding specificity principle

Tulving → if cues present at encoding are present at recall then memory can be accessed

Retrieval cues case studies

• Godden and Baddeley → context dependent forgetting → divers learnt words on land and recalled them on water, recall was 40% lower in mismatched conditions due to absence of cues

• Carter and Cassiday → state dependent forgetting → ppt learnt on drug and recalled w/o drug, recall was worse in mismatched conditions due to absence of cues

AO3 Retrieval cues

• ✅RWA → e.g. if you walk into a different room you forget what you were doing, so the research reminds us of strategies to increase recall in real world, ↑ ecological validity, ↑ generalisability

• ✅research support (Godden & Baddeley and Cassiday & Carter) → scientific

• ❌low ecological validity / artificial stimuli

• ❌doesn’t explain permanent forgetting → cues triggered the memory so only temporary forgetting is explained, but not when the memory is genuinely lost from LTM

What is interference?

Whats retroactive interference

Whats proactive interference

• interference → forgetting because one memory blocks another

• retroactive → cant remember old memory because newer one blocks it

• proactive → cant remember new memory because older ones block it

Case study for interference

McGeoh and McDonald → ppt learnt list of 10 words then learnt second list in 6 conditions with either synonyms or antonyms etc. and were asked to recall first list

findings → synonym as second list had worst recall because interference increases when words are similar

AO3 for Interference

• ✅research support - McGeoh and McDonald (done in lab)

• ❌artificial stimuli → word list has low mundane realism

• ✅RWA → e.g. rugby players were asked to recall the names of teams they played against, those who played most games due to less injuries had worst recall, suggesting interference

• ❌conflicting research → Tulving found that cues overcome interference as when ppt were given a cued recall test, accuracy of recall increased, showing interference is a temporary loss in LTM - not predicted by the explanation, ↓ construct validity

What is the working memory model?

• Baddeley and Hitch

• representation of STM , suggests it is an active process and not a unitary store

What is the central executive

Controls the three slave systems , allows individuals to make decisions, has limited storage

What is the phonological loop?

• deals with auditory info, holds 2 seconds worth of info, encodes acoustically

• phonological store → stores what you hear

• articulatory process → allows maintencance rehearsal

What is the Visuospatial sketchpad

• deals with visual information, holds 3-4 items of info

• visual cache → stores what you see

• inner scribe → stores arrangement

Working Memory Model AO3

• ✅research support - dual tasks (Baddeley asked ppt to do 2 visual tasks and a visual and verbal task) → harder to do 2 visual tasks as they both use VSS so STM has clear distinct stores

• ❌low ecological validity & low mundane realism (lab studies)

• ❌central executive lacks research → Baddeley said its the most important but least understood and is made up of subcomponents, which challenges integrity of model

• ✅clinical studies → KF brain injury, VSS & phonological loop are 2 seperate stores located in different brain regions (PL was damaged, VSS was fine) - diff visual and acoustic memory stores

What is eye witness testimony

when someone is asked to testify about an event they witnessed

How is EWT affected ?

Leading questions

Post event discussions

Anxiety

How do leading questions affect EWT

• Substitution explanation → the wording of the question interferes with the original memory, distorting accuracy

• Response bias explanation → the question influences the response given

What is the case study for Leading Questions?

Loftus and Palmer (1974)

Procedure → 45 Ppt (UNI STUDENTS) watched same video of car accident and were given questionnaires that asked questions about the speed of the cars with varying verbs such as “contacted, smashed, hit and bumped”

Findings → Ppt with intense verb “smashed” in their questionnaire said the cars were going fastest

Conclusion → the verbs gave an impression of the speed of the cars, therefore leading questions have an affect of EWT

AO3 for Loftus and Palmer’s Leading Questions experiment

• ✅lab study → controlled, increases validity, decreases confounding variables

• ❌artificial tasks + lab→ low mundane realism, low ecological validity, (counter) however, due to ethics, its safer to have ppt watch video of car crash than see one in real life

• ❌Non-representative samples (uni students), ↓population validity, (counter) however the basic cognitive processes involved in memory are likely to be universal, limiting the impact of this issue

• ✅RWA → Loftus stated that police shouldn’t use leading questions with witnesses, decreasing wrongful convictions in the justice system. This improves legal system and protects the innocent from unreliable EWT

How does post-event-discussion affect EWT?

• Source monitoring theory → memories are genuinely distorted, when witnesses discuss a crime, they mix (mis)information from other witnesses with their own memories

• Conformity theory → witnesses go along with each other due to social approval because they believe other witnesses are right

Case study for Post Event Discussion

Gabbert et al. (2003)

Procedure → ppt were put in pairs where they watched different videos of the same crime (so one participant could see stuff the other couldn’t & vice versa) and then they discussed what they saw before recall

Findings → 71% of ppt recalled events they didn’t see but discussed. Those who didn’t discuss events made no mistakes

AO3 for Post Event Discussion

• ✅research support - Gabbert et al

• ✅/❌ lab study → highly controlled but demand characteristics - ppt want to help so they guess when answering so their memory isn’t actually distorted

• ❌unethical as watching violent crimes causes anxiety → offsets protection from harm, aims of study were prioritised over participant rights

• ❌RS doesn’t explain conformity theory of how P.E.D affects EWT → e.g. 71% recalled a blend of what they had seen and discussed, suggesting source monitoring theory. 

What is anxiety ?

• a state of physiological or emotional arousal

• a natural response when we feel we are under threat

How does anxiety negatively affect EWT ?

• Weapon focus → anxiety leads to physiological arousal where eyewitness is prevented from paying attention to environmental cues and only pays attention to a particular aspect of the environment, e.g. a weapon

What is the research support for weapon focus?

• Johnson and Scott

• Procedure → ppt thought they were participating in lab study. In low anxiety condition, ppt heard casual conversation and saw man walk out with pen and grease. In high anxiety condition, ppt heard heated argument and saw man walk out with a knife and blood

• Findings → Low anxiety 49% correctly identified man and in High anxiety 33% correctly identified man

• Conclusion → tunnel theory of memory → people have enhanced memory for central events

AO3 of Johnson and Scott (1976)

• ✅lab study → highly controlled, reliable

• ❌ethical issues - deception

• ❌anxiety isn’t relevant to weapon focus → tested unusualness rather than anxiety, e.g. weapon focus occurred because ppt were surprised, Pickel(1998) found accuracy was lowest in identifying ‘criminal’ when object in their hand was unexpected (like raw chicken)

How does anxiety positively affect EWT?

• Fight or flight → A stressful situation rises physiological arousal which prepares the body for fight or flight which increases alertness so we become more aware of environmental cues.

What is the research support for fight or flight?

• Yuielle and Cutshall

• Procedure → 13 witnesses of a shooting were interviewed 4-5months after event and it was compared to the original police interview. ppt self reported their stress levels.

• Findings → ppt that reported high anxiety had 88% accuracy recall and ppt that reported low anxiety had 75% accurate recall

AO3 for Yuielle and Cutshall

• ✅high ecological validity → valid report of EWT

• ❌stress levels are subjective, lack of control

What is the Cognitive Interview?

• Fisher and Gieselman (1992)

• a method of interviewing eyewitnesses to help them retrieve accurate memories

• increases accuracy of EWT using evidence based psychological knowledge

What is the Yerkes Dodson Law?

• Inverted U theory → When stress is too high or too low, performance is lower and EWT is less accurate but when stress is moderate, performance is highest.

What are the steps of cognitive interview

1. Report everything

2. Reinstate the context

3. Reverse the order

4. Change perspective

How does “reporting everything” improve EWT?

Small details can help witness trigger significant memory

Explain how “reinstating the context” improves EWT

Witnesses visualise themselves in the same environment and emotional state which supports encoding specificity principle

How does reversing the order improve EWT

• reduces likelihood of expectations influencing EW memory

• makes fabrication more difficult

How does “changing perspective” increase EWT

Helps disrupt personal schema and ensures objective recall

What is enhanced cognitive interview?

it focuses on social dynamics where the interviewer reduces anxiety by creating a supportive environment. For example by using open questions and eye contact

AO3 for Cognitive interview

• ✅research support (meta analysis) → Kohnken et al reviewed 55 studies comparing C.I. & E.C.I w/ standard police interviews and found C.I produce 41% more accurate information than police interviews, showing C.I can ↓ wrongful convictions and improve justice system

• ❌time consuming - impact on police force → training takes long as well as the interviews themselves, showing C.I is unrealistic

• ❌doesn’t work for all age groups → e.g. changing perspective may be too complex for younger witnesses, so effectiveness varies with age ↓population validity + generalisability

• ❌not all stages are useful → reinstate the context and report everything produce better recall than other stages