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D U R AT I O N
LT M – U N L I M I T E D
S T M – L AS T S B E T W E E N 2 - 3 0 S E C O N D S
Models of memory
Duration LTM – Unlimited, STM – Lasts between 2-30 seconds
Short term memory: Peterson and Peterson: He used 24 university students to do an experiment using trigrams 3 letters were read e.g- TXU or SQP, the participant had to remember
these letters whilst counting down in 3’s or 5’s backwards for a period of time between 3-18 seconds when they had to repeat it back
80 % remembered after 3 seconds 10% remembered after 18 secondsEvaluation: Low ecological validatity, uni students – one age group Controlled environment – extraneous variables - clear cause and effect
Long term Memory: Bahrick et all A longitudinal study of 392 graduates were used. The graduates were shown pictures from their yearbook They were split into two groups of recognition group (given names to
chose from) and recall group (had to remember name) Recognition – 90% remembered after 14 years
60% remembered after 47 years Recall – 60% remembered after 7 years
less than 2% remembered after 47 years People can remember things after a lifetime Evaluation: Longitudinal study/large group number – better validity Only one type of memory tested
CapacityLTM – unlimited STM – 7 plus/minus 2
Short Term Memory:
Miller
Letters were given to participants such as C-A-T-W-A-L-L
It was found that it was easier to remember ‘C-A-T’ and ‘W-A-L-L’ as you could remember it as separate words
It didn’t matter how many individual parts of information there was, it was the ‘chunks’ of words that people remember and these are what measure out memory.
He decided that from this, we could remember 7 +/- 2 amounts of chunks
Evaluation:
Implications – Phone numbers are chunked so are easier to remember – ecological validity
Individual differences – some peoples memory are better than others
Long Term Memory:
Because long term memory is unlimited there is no proof needed because no-one has reached their maximum memory.
E N C O D I N G
LT M – S E M AN T I C AL LY
S T M – AC O U S T I C O R V I S U AL LY
Models of memory
EncodingLTM – Semantically STM – Acoustic or visually
Short Term Memory: Conrad: Gave participants a series of 6 letters visually, immediately they would
have to write the letters. He found that participants substituted letters which sounded the
same. For example: B for V and F for S. This showed that letters had been encoded by sound despite being
presented visually. Evaluation: Individual differences – personal preference towards how we
remember best No longer a need to chunk – phones store numbers for us – mundane
realism
Long Term Memory: Baddeley: Participants were divided into 4 groups; Acoustically similar words (man, mad, map) Acoustically dissimilar words (pen, day, few) Semantically similar words (great, big, large) Semantically dissimilar words (hot, old, late) After 20 mintues… Recall was similar for acoustically similar and dissimilar Semantically similar was 55% and semantically dissimilar was 85%
Evaluation: Lab experiment – didn’t reflect everyday use of LTM It might simply be that short words are easier to recall than long
words because they are more familiar to us
The working memory model –Baddeley and Hitch
Central Executive: Direct attention to tasks Has a limited capacity and cannot deal with lots going on at once Sends information to the required part of the brain
Phonological loop: It deals with any auditory information Has a limited capacity by maintains rehearsal Baddeley eventually split it into Phonological store (holds words
heard) and Articulatory process (holds words seen/heard and repeats)
Visuo-Spatial Sketch Pad Visual or spatial information is stored in this part Arrangement of objects Acts as our ‘Inner scribe’
Episodic Buffer It is used as an extra storage system for when the central executive is
busy It takes information for all areas
Central ExecutiveVisuo-
spatial sketch pad
Episodic buffer
Phonological loop
Evaluation – The working memory model – Baddeley and Hitch
Strengths: Case study of L.H – Involved in a road accident. Performed better
on spatial tasks than visual. This suggest that there is separate storage systems which is what the model suggests.
Baddeley – The phonological loop explains why the ‘word-length effect’ occurs. It is harder to remember longer words rather than shorter words because longer words are harder to rehearse which is known as the ‘Word length effect’ . The reason we cant remember the longer words is because of articulary suppression meaning its harder to rehearse the long words.
Baddeley – Asked participants to press keys on a key board however the keys could not make a pattern. This was either carried out alone or with another task such as reciting the alphabet or counting. He found that the tasks were competing for the same space in the central executive and phonological making it very hard to do.
Weaknesses Case study of EVR – They had a brain tumour removed. When
tested, they performed well on reasoning but poor at decision making which according to the model was meant to both be from the central executive. This suggests that the central executive must be more complex than what the model suggests. The central executive is far to simplistic and should have more components.
The central executive doesn’t explain anything other than how it diverts attention.
There are other models that have been used to explain how memory is stored e.g- the Multi-store model which also has supporting studies.
The Multi-Store model of memory
Sensory memory
STM LTM
Constant rehearsal
Decay Decay Decay
Elaborate rehearsal
Retrieval
Environmental stimuli
HapticEchoic
Iconic
Attention
Sensory Short-term Long-term
Capacity - 7 +/- 2 Unlimited
Duration 1-2 seconds 2-18 seconds Many Years
Encoding Iconic/Echoic Acoustically/visually
Semantics
The Multi-Store model of memory
Strengths:Glanzer and Cunitz - Gave participants 20 words to remember. Told to
recall the words in any order. They remembered the words from the beginning (LTM) and those from the end (STM). Supports as there is clear evidence of separate stores (long and short term)
Scans - PET or MRI scans take images of the brain and see what region is active when doing a short term or long term memory task suggesting separate stores.
Case study of HM - Had an operation to remove his hippocampus to reduce the epilepsy he was suffering. He could no longer store any LTM which proves evidence for separate stores as there was a breakdown between STM and LTM.
Weaknesses:Schacter at al – Suggested 4 LTM stores; Semantics, episodic, procedural and perceptual – representation system. This differs and challenges the MSM
Case study of KF - Suffered brain damage which resulted in difficulty dealing with anything short term verbally. However, he had a normal ability when it came to processing visual short term information. This suggests that short term memory is not just a single store and must be more complex.
Eyewitness testimonyMisleading information/leading questions
Misleading information/ leading questions The wording of a question can change the way you answer
Agree:
Loftus & Palmer:
45 students watched slides or film clips of a car crash
They were asked in the interview how fast they thought the car was going and if they saw any glass
In this question the changed the describing word of the car from ‘bumped’ ‘collided’ ‘smashed’ ‘contacted’
The speeds predicted were much higher if the word ‘smashed’ was used at 40mph however when the word ‘contacted’ was used it was only 31mph.
Also, more people said that there was glass when ‘smashed’ was used rather than ‘contacted’
Disagree:
Yuille & Cutshall
After interviewing 13 people from a bank robbery, they asked 2 misleading questions 4 months after the event.
Despite these misleading questions, the witnesses still provided accurate recall which matched their initial reports.
Eyewitness testimonyAnxiety
Anxiety Research has looked at the effect of anxiety and accuracy of the
witness
High anxiety is better:Christianson & Hubinette Survey was done on 110 participants who witnessed a real bank
robbery Those who were actually threatened by the robbery remembered the
event in much more detail than those who were just standing This shows that if they were threatened they had high anxiety levels
but they remembered more
Medium anxiety is better:Yerkes-Dobson They found that a medium levels meant that they were more alert than
normal but no so much so that their attention was diverted Performance worked better when in average anxiety levels
Low anxiety is better:Loftus Participants were exposed to either situation 1) heard a low key
discussion of a lab experiment failure. A person emerges from a lab holding a pen and had grease on his hands. 2) heard a loud discussion of a lab experiment failure with the sound of breaking chairs and smashed glass. A person then emerges with blood on his hands and a small knife.
They were then shown 50 photos of potential men which they had to indentify. 49% correctly identified the man in condition 1, but only 33% in condition 2.
This shows that lower levels of anxiety result it better identification.
Eyewitness testimonyAge of witness
Age of witness
Depending on the age of a witness, they could give more or less accurate detail and some age groups are affected more on misleading information.
Age differences
Yarmey
651 adults were stopped in a public place and asked to recall the psychical appearance of a young women of which they had just spoken to 2 minutes ago
Young and Middle aged adults had better recall whereas the older adults were less confident
There was little difference in accuracy of recall depending on age as the older adults still remembered, they were just a little less confident
Own age bias
Anastasia and Rhodes
Participants were divided into three groups (18-25) (35-45) (55-78)
They were all shown 24 photos of which they had to rate on attractiveness
After an activity, they were then presented with 48 photographs including 24 ‘distracter’ photos
The age groups were better at identifying people from their own age groups
Eyewitness testimonyEvaluation
Strengths:
*any strength of any study
Studies support the factor that influences eyewitness testimony
Weaknesses:
Drugs or alcohol can impair attention so recall might be inaccurate
Participants are not emotionally involved in a video or picture compared to actually seeing an event so will pay less attention
*any criticism of any study
Cognitive interview
There are 4 main stages used in the cognitive interview:
Mental reinstatement- The interviewer will encourage the interviewee to try to picture themselves back in the scene and recreate what happened and where everything was in their mind
Report Everything- The interviewer must record everything that is said even if they feel as if what is being said is completely pointless or irrelevant
Changing the perspective- The interviewer could ask the interviewee to try and explain what would have happened if they were another person at the scene and imagine how it would have appeared to a different witness
Changing the order- The interviewer may ask for them to recall different parts of the scene put in a different order to see if there is any extra information given
Cognitive interview
Strengths:
Milne and Bull:
Undergraduates and children were interviewed using one individual section of the cognitive interview
They found that by using and ordinary interview or only using one stage of the cognitive interview recall was all similar
When two or more stages of the cognitive interview were combined, recall of the event was drastically higher
Mello and Fisher:
Used 72 and 22 year olds and tested the cognitive and standard interview on them
Cognitive was most effective in both age groups but more helpful for older participants
Memon:
Used a cognitive interview in Brazil where the normal interview would involve torture
Cleaning staff of a university watched a video of an abduction
Compared to the standard interview, the cognitive one increased recalled information
Weaknesses:
In some police forces, only certain aspects of the interview are used meaning its difficult to evaluate its effectiveness and results cannot be compared
Memon:
Detectives received around 4 hours training on how to use the cognitive interview which did not actually increase the amount of information given
The cognitive interview takes up so much time which is usually not available so it is easier to use a standard interview
Verbal & Visual Mnemonics
Verbal
Acronyms – Where a word or a sentence is formed by using the first letter of a words and creating a phrase to remember which each new word. E.g. BBC means the British Broadcasting Corporation
Acrostic – A poem or sentence formed by from using the first letter of each word and changing them to make a mini story E.g. Richard Of York Gave Battle In Vain means Red, Orange, Yellow, Green, Blue, Indigo and Violet.
Rhymes – Groups of words formed to make a rhythm E.g. ‘Twinkle Twinkle little star’ is used to remember the alphabet
Chunking – Dividing long strings of information into smaller more manageable chunks E.g. Postcodes or telephone numbers
Visual
Method of Loci: A mental technique where by you remember a set location that is already
stored in your brain. You then picture and item or material in different smaller places within
your chosen location You then begin to associate that small location with the item or material
Peg word method: The person would use a pre-learnt rhyme and combine each line of the
rhyme with an item or material You would then visualise each line of the rhyme adding in the item You then learn to associate each of the lines visually with that item
Verbal & Visual Mnemonics
Strengths
Gruneberg:
30% of psychology students used techniques such as acronyms to help revise
Giddens:
Children with learning disabilities preferred using verbal techniques over visual ones
However these techniques were found to be ineffective over a long period of time
O’Hara:
Used older adults
Found that the method of Loci was more useful over a long period of time
Weaknesses:
Some studies were in lab conditions – artificial environment so has low ecological validity
Cannot generalise grunebergs study as only psychology participants from a university were used
O R G AN I S AT I O N & E N C O D I N G
S P E C I F I C I T Y P R I N C I P L E
How Mnemonic techniques work
Organisation
Organisation:
By organising data, we establish links that help recall information i.e- word associations and visual images create links to other information
Normally, the brain will remember information in a self-organising process that’s pieces together bits of information e.g- the smell of bacon makes you salivate because you have eaten it before and recall it tastes nice and as a result salivate – your brain associates the link between the nice taste and bacon
Strengths:
Brower and Clarke:
Participants were given 112 words to learn
Group 1 were given them in a conceptual hierarchy and group 2’s words were not organised
Group 1’s recall was 2-3 times better than those given words in a random order
By creating a story to remember information means we can attach information which is how long term memory is stored (semantics)
Weaknesses:
Individual differences – some people learn better in different ways and organisation doesn’t always work for everyone
Encoding specifity principle
Memory is most effective when what item the memory is attached to is there when trying to retrieve information – retrieval cues
Recall and recognition thus may be triggered by elements of the context being present e.g- wanted something that is downstairs, gone downstairs and then forgotten what you wanted and when you go back upstairs again you remember what it was that you wanted
When you store something in memory, the memory is not just of the item being stored but also of the context in which the memory occurred
Strengths:
Tulving and Thompson:
A list of words were given to participants all of with had a ‘cue’ word
Group 1 were asked to recall the words freely
Group 2 were asked to recall the words but also were given the ‘cue’ words
Group 2 out –performed group 1
Real life application – triggers can remind us of forgotten memories
Weaknesses:
If the cue is not given at the tine of storing information then the process doesn’t work