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

• There was RESEARCH SUPPORT as other researchers found support for his findings

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

Limitation 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

Study of encoding into STM

• Baddeley asked ppt to recall words in order they were told.

• He found that we encode acoustically for STM

Strength of research of encoding into STM

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

Limitation of encoding into STM

• Baddeley’s research uses artificial stimuli as ppt recalled random words which were not representative of everyday life

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

• Bahrick used information that was applicable to real life e.g recognising faces

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

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

Limitations of MSM

• No evidence to support there is more than one STM store

• Evidence to support prolonged rehersal is not needed for info to be passed from STM to LTM

• MSM is outdated - simplifies LTM

Types of LTM

• Procedural → memory for actions and skills

• Episodic → ability to recall events in life

• Semantic → contains general knowledge

AO3 for LTM research

• research support for different types of LTM (patient with brain damage)

• real life application

• conflicting neuroimaging findings

• lack of control variables

What is retrieval failure

What are cues

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

• cues → a trigger that helps access a memory

Retrieval cues case studies

• Baddeley → context dependent forgetting → divers learnt words on land and recalled them on water

• Carter and Cassiday → state dependent forgetting → ppt learnt on drug and recalled w/o drug

AO3 Retrieval cues

• real world application

• research support (Baddeley and Cassiday and Carter)

• low ecological validity / artificial stimuli

• context effects X

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 and were asked to recall first list

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

AO3 for Interference

• research support (done in lab)

• artificial stimuli

• real world application (rugby players)

What is the working memory model?

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

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)

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

• central executive lacks research

• clinical studies - VSS & phonological loop are 2 seperate stores

What is eye witness testimony

when someone is asked to testify about a crime 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

• Response bias explanation → the question influences the response given

What is the case study for Leading Questions?

Loftus and Palmer (1974)

Procedure → Ppt 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

• Real world application

• Artificial tasks

• Non-representative samples

How does post-event-discussion affect EWT?

• Source monitoring theory → memories are genuinely distorted. When witnesses talk about an event they witnessed, they wont be able to recall if it was their memory or someone else’s.

• Conformity theory → recall of events changes to match each others because of social desirability

Case study for Post Event Discussion

Gabbert et al. (2003)

Procedure → ppt were put in pairs where they watched same video of a crime in different POVs (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

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

AO3 of Johnson and Scott (1976)

• highly controlled, reliable

• ethical issues - deception

• tested unusualness rather than anxiety

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

• 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?

• 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?

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

• time consuming - impact on police force

• low generalisability - age groups

• not all stages are useful