AS Psychology - Memory

Includes: Multi-Store Model, Working Memory Model, Eye Witness Testimony, Cognitive Interview and Strategies for Memory Improvement

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  • Created by: Pennaling
  • Created on: 24-11-14 14:42

Multi-Store Model of Memory

Multi-Store Model of Memory by Atkinson & Shiffrin

Information flows in one direction through 3 unitary stores : sensory store, short-term store and long-term store.

Information enters sensory memory and is held for fractions of seconds and is likely to decay if not attended to. If attended to information will be transferred to short-term store. Information can remain in short-term memory for a short time if it is rehearsed. If information is rehearsed enough it can be transferred to long-term memory.

Short term and long term stores differ in:

  • Capacity - how much information can be held
  • Duration - how long the information can be stored for
  • Encoding - how the information is processed into something that can be stored
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Multi-Store Model - Capacity

Capacity of Short-term Memory

  • Jacob's (1887) devised the 'serial digit span technique' to investigate how much information can be held in STM.
  • Findings: Jacob's found capacity of STM was between 5 and 9 items.
  • Miller (1956) did a review of studies looking at capacity and found that STM capacity is 7 ± 2, he called this the 'magic number 7'.

Capacity of Long-term Memory

  • Potentially limitless 
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Multi-Store Model - Duration

Duration of Short-term Memory

Measured using the Brown-Peterson Technique.

  • Participants were shown a consonant trigram e.g. VXW
  • Rehearsal was prevented by asking them to count back in 3's.
  • After intervals of 3, 6, 9, 12, 15 or 18 seconds, participants were asked to stop counting + repeat the trigram.
  • Findings: after 18 seconds the % recalled correctly was very low, therefore showing that the memory for the trigram had decayed. Peterson + Peterson concluded that the duration of STM is about 18 seconds.

Duration of Long-term Memory

  • Bahrick et al (1975) found that people can recall + recognise names + faces up to 48 years later, suggesting that duration of LTM is long lasting/limitless.
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Multi-Store Model - Encoding

Encoding in Short-term Memory

  • Baddeley (1966) found that there is acoustic confusion with words that sound alike.
  • STM encodes acoustically.

Encoding in Long-term Memory

  • Baddeley (1966) found that there was semantic confusion with words that have similar meaning.
  • LTM encodes semantically.
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Evaluation of Multi-Store Model

Strengths:

1) Brain scans e.g. fMRI scans have shown different areas of the brain are active when doing memory tasks.

  • STM: prefrontal cortex
  • LTM: hippocampus
  • This shows that STM and LTM are different stores.

2) Milner (1956) studied the case of H.M. whose hippocampus was removed. He was unable to form new long-term memories although his STM - as measured by serial digit span - was unaffected. This shows that STM + LTM must be different stores.

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Evaluation of Multi-Store Model

Weaknesses:

1) Rehearsal is not the only process.

  • Craik + Lockhart (1972) stated that depth of learning leads to LTM, rather than simple repetition.
  • Some things are just more easily recalled even without rehearsal (flashbulb memories) + MSM doesn't account for this.

2) Oversimplification of our memory - stores are not unitary.

  • Clive Wearing lost his LTM episodic memory (memory for events) + semantic memory (memory for facts) but not his procedural memory (how to play the piano). This suggests that there may be more than one type of LTM.
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Working Memory Model

The Working Memory Model by Baddeley & Hitch (1974)

  • Concerned with short-term memory only
  • Baddeley + Hitch proposed that STM was not a unitary store but a flexible + complex system consisting of a control mechanism assisted by two 'slave' systems.
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Working Memory Model - Components

The Central Executive:

  • Supervisory component.
  • Controls which information is and isn't attended to.
  • Limited capacity + can only attend to a certain number of things at one time.

Phonological Loop:

  • Limited capacity, temporary memory storage system, hold verbal information in speech-based form.
  • Consists of short-term storage system called the phonological store and an active rehearsal system called the articulatory process, which allows words to be kept in memory by subvocal repetition.

Visuo-spatial Sketchpad:

  • Limited capacity, temporary memory storage system that helps people to navagative + interact with their physical environment.
  • Includes a visual cache, a temporary visual store + an 'inner scribe' that acts as a rehearsal mechanism.
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Evaluation of Working Memory Model

Strengths:

1) Dual Task Technique (Baddeley et al, 1973)

  • Participants were given a simple tracking task (following a spot light with a pointer as it moved around a circular path) while carrying out either a simultaneous visual or verbal task.
  • Participants had difficulty performing the two visual tasks because the two tasks were competing for the same limited resources of the visuo-spatial sketchpad.
  • However, participants could successfully carry out the tracking task whilst performing a verbal task, because they were making use of the separate resources of the visuo-spatial sketchpad and the phonological loop.
  • This supports the idea that there are separate components in the working memory.

2) Practical Applications

  • Working memory capacity might be used as a measure of suitability for certain jobs e.g. it has been used as a recruitment tool for the US air force.
  • This shows that the model has real life applications.
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Evaluation of Working Memory Model

Weaknesses:

1) Not a complete model

  • The model doesn't account for musical memory, because participants can listen to instrumental music without impairing performance on other acoustic tasks.

2)Role of central executive remains unclear

  • The central executive is an important part of the model but psychologists do not know much about how it works + it's role is unclear.
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Factors Affecting Accuracy of Eye Witness Testimon

Misleading Information

Loftus + Palmer - Experiment 1

  • 45 participants asked to watch 7 clips of car accidents + estimate the speed. "How fast were the cars going when they hit each other?" Hit was variously replaced with collided, contacted, smashed and bumped.
  • Found that the verb used influenced the average speed estimate, the highest being smashed at 41mph, the lowest being contacted at 32mph.

Loftus + Palmer - Experiment 2

  • 150 participants divided into 3 groups + shown a clip of car accident.
  • Condition 1 - participants asked "How fast were the cars going when they smashed each other?"
  • Condition 2 - participants asked "How fast were the cars going when they hit each other?"
  • Condition 3 - control group where participants were not asked about speed.
  • Participants returned 1 week later + asked "Did you see any broken glass?", 32% of smashed condition mistakenly answered yes, 14% for hit + 13% for control.
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Factors Affecting Accuracy of Eye Witness Testimon

Anxiety

Johnson + Scott

  • 2 groups of participants in waiting room for experiment on human memory. All heard discussion in adjoining room.
  • Condition 1 - discussion about an equipment failure, a man emerged holding a pen with grease on his hands.
  • Condition 2 - heated discussion, heard bottles breaking + chairs crashing, a man emerged holding a letter opener covered in blood.
  • All asked to identify the man from 50 photos, 49% in condition 1 were accurate, 33% in condition 2.

Christianson + Hubinette

  • Surveyed 110 people witness to 22 genuine bank robberies
  • Some had been bystanders, whilst other were directly threatened by robbers.
  • People subjected to greatest anxiety showed more detailed + accurate recall than onlookers.
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Factors Affecting Accuracy of Eye Witness Testimon

Age

King + Yuille

  • Staged event for 6, 9, 11 + 16 yr olds. Participants seated in a room when a stranger walks in to care for some plants. Before leaving, stranger noted the time + indicated it was late. Children were interviewed about what they could recall and asked leading questions "Which arm did the man wear his watch?" (When he wasn't wearing a watch).
  • Found that 6 yr olds are significantly more suggestible and recalled less than the 9-16 yr olds.

Anastasia + Rhodes

  • Participants aged 18-78 were shown 24 photos of people and asked to rate them for attractiveness. Participants then did a 'filler' activity + were presented with 48 photos, 24 previously seen, 24 'distractors'.
  • Found that recognition rates for young participants (87%) + middle aged participants (88%) were more accurate than older participants (61%).
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Evaluation of Eye Witness Testimony Research

Misleading Information:

  • Ethical Issues: informed concent (often deceived) + psychological harm (experienced a car accident)
  • Methodological Issues: Lab studies lack ecological validity + demand characteristics (may pay more attention in an experiment). If participants know it has real consequences EWT might be more accurate.
  • Practical Applications: knowing how to interview for accurate EWT.

Anxiety:

  • Methodological Issues: JOhnson + Scott minimised demand characteristics by using deception - increased validity.
  • Christianson + Hubinette - lack control of extraneous variables. Highest anxiety were also closer to the event, being able to see clearly might lead to greater accuracy of EWT.
  • Ethical Issues: Deception/lack of informed consent + psychological harm.

Age:

  • Led to development of relevant theories about memory.
  • Anastasi + Rhodes discovered own age bias. All groups more accurate when identifying members of their own age group. Problem when older people asked to identify young.
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Improving Accuracy of EWT using Cognitive Intervie

Cognitive Interview - procedure designed for police interviews. 2 main principles researched by Geiselman:

  • Context Reinstatement - Mentally reinstate environmental + personal context of crime in mind of witness. Sights, sounds, smells, feelings + emotions. "Recall scene, weather, what you were thinking + feeling at the time + the events leading up to the incident."
  • Report Everything - Every detail must be reported, however unimportant.
  • Recall from Changed Perspective - Report from range of perspectives (other bystanders/criminal).
  • Recall in Reverse Order - Encourage witness to recount details of event in different orders.
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Evaluation of Cognitive Interview

Strengths:

1) Geiselman compared cognitive with standard + hypnosis.

  • Participants watched a short film of a violent crime. 2 days later, divided into 3 groups + interviewed by police.
  • Cognitive resulted in average of 41 correct responses, compared to 38 for hypnosis and 29 for standard.
  • This shows cognitive is more effective than standard.

2) Stein + Memon tested effectiveness of cognitive interview in Brazil.

  • Women recruited from cleaning staff at a university were asked to watch a video of an abduction.
  • Compared to standard interview, cognitive increased the amount of correct information recalled.
  • Cognitive interview provides new approach to interviewing witnesses in Brazil - practical applications across the world.
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Evaluation of Cognitive Interview

Weaknesses:

1) Use in real life

Found that police officers find cognitive interview is time consuming, therefore not the most practical technique to use in real life.

2) Not effective

Cognitive interview becomes less effective as time passes after the event + shows small increase in incorrect info when cognitive is used.

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Strategies for Memory Improvement

Visual Imagery: Method of Loci

  • Linking words/material you need to know to a series of locations known to you

Organisational Techniques: Spider Diagrams

  • Notes of information in form of drawing usually branching pattern centred around a main component. Information is organised + each diagram has a distinct visual appearance - more memorable.

Verbal Techniques: Acronyms + Acrostics

  • Acronyms - Word/sentence formed from initial letters of other words. e.g. Roy G Biv for colours of the rainbow.
  • Acrostics - Poem/sentence where first letter in each line/word forms the item to be remembered. e.g. Richard of York gave battle in vain, for colours of the rainbow.
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Evaluation of Strategies for Memory Improvement

Strengths:

1) Bower gave participants 100 different cards, each had 2 unrelated words on it

  • Group 1 - participants asked to mentally produce an image to link words
  • Group 2 - participants just asked to recall the words
  • Participants in group 1 recalled 80% when shown 1 word, group 2 recalled 45%. Method of Loci improves recall.

2) Paivio proposed words + images processed separately - words that can be made into images are double encoded in memory - increasing likelihood of remembering (dual-coding hypothesis).

Weaknesses:

1) Difficult with complex/abstract material that doesn't lend itself easily to imagery

2) Some people find it difficult to use visual imagery.

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