4.1.2 - Memory Flashcards
Complete
What does the short term memory do?
Stores the information we are currently aware of. Encoded acoustically (for sound)
What does the long term memory do?
Stores memories from the past, has continual storage of information outside our awareness. Coding is semantic (for meaning)
Define coding
The format in which information is stored in memory
Define rehearsal
Attending to information so it stays in your memory e.g. verbally repeating it over and over
Define capacity
The amount of information held in a memory store
What is the capacity of the STM?
5-9 items
What is the capacity of the LTM?
Unlimited
Who developed the concept of chunking?
George Miller
What was Miller’s experiment on chunking?
He asked ppts to recall different amounts of letters, words or numbers
He concluded we can recall 7 items, but we can remember more as long as we break the info into 5-9 manageable chunks
We can remember 5 words as easily as we can remember 5 letters through chunking
What was Jacob’s digit span experiment in 1887?
- Researcher gives a number of digits and a participant has to recall them in order
- Researcher increases the amount by 1 digit until the participant recalls the order wrong
- This determines their digit span
- The mean span for ppts was 9.3 items and lower for letters at 7.3
- This shows that the STM is a limited capacity store
What is chunking?
Breaking information into 5-9 manageable chunks
Define duration
The length of time information can be held in memory
What is the duration of the STM?
Between 18-30 seconds
What is the duration of the LTM?
A potential lifetime
What was Bahrick’s study into LTM?
- 1975
- 392 pts from Ohio from ages of 17-24
- Obtained their high school year books
- Tested recall with
1. Photo recognition of 50 photos
2. Free recall test - pts recalled names of graduating class
What were the results of Bahrick’s study on LTM?
15 years after graduation - 90% accurate in photo recognition
48 years after - 70% photo recognition
Names - after 15 years = 60% accurate
- after 48 years = 30% accurate
This suggests that long term memory lasts a very long time
Evaluation of Bahrick’s experiment?
- temporal validity
- external validity
- ethnocentric
- due to it being a longitudinal study there may have been confounding variables e.g. ppts may have stayed in contact
Coding, capacity and duration evaluation?
:( - Baddeley’s study used artificial stimuli, the word lists had no personal meaning to participants - lack external validity
:( + :) - Jacob’s study was conducted a long time ago - extraneous variables may not have been controlled - however other research has confirmed the results supporting its validity
:(- Cowan (2001) research showed the capacity of STM was only 4 chunks - Miller may have overestimated the capacity of STM
:) + :( - Peterson and Peterson used artificial stimuli - lacks ecological validity - although, we remember meaningless things such as phone numbers it is not totally irrelevant
:) - Bahrick et al - studied real-life meaningful memories - although variables not controlled
What is iconic memory?
Visual information is coded visually
What is echoic memory?
sound information is coded acoustically
When does maintenance rehearsal occur?
When we repeat material to ourselves over and over again
What does the multi-store model of memory show?
The model describes how information flows through the memory system. It suggests that memory is made up of 3 stores linked by processing
What is the sensory register and how does it work?
- a stimulus from the environment will pass into it
- sights, sounds, smells , tastes, etc
- material in Sensory Registers lasts only briefly (less than half a second)
- has a high capacity
- information only passes further into the system if you pay attention to it
How do we recall material stored in the LTM?
Retrieval
Who created the Multi-store model?
Atkinson and Shiffrin , 1971
What is the Working Memory Model?
- An explanation of how STM is organised an how it functions
- It consists of 4 main components
Who created the Working Memory Model?
Baddeley and Hitch , 1975
What does the central executive do?
It directs attention to particular tasks and monitors incoming data
It controls the other systems by determining how resources will be allocated
Has a limited processing capacity
Evaluation of the Multi-store model?
:) - Bahrick 1975 - Showed that LTM lasts forever/ long time
:) - Peterson + Peterson - Shows that STM lasts 18s - shows a difference between the 2 stores
:) - First complex model of human memory
:( - Shallice + Warrington 1970 - STM for digits was poor when read out but was better when he read them himself. Could be another STM store for sounds - must be a store to process visual info and one to process auditory info - shown in WMM but MSM doesn’t take this into account and so may be considered incomplete
:( - Craik + Watkins, 1973 - According to MSM, what matters is the amount of rehearsal but what really matters is the type of rehearsal: Maintenance Rehearsal, Elaborative Rehearsal - This cannot be explained by the model
:( - A lot of research supporting MSM uses artificial stimuli in their experiments
:( - Research suggests LTM is not a unitary store and actually has 3 parts
When does elaborative rehearsal occur
Occurs when you link the information to your existing knowledge or you think about what it means (needed for long-term storage)
What does the phonological loop do?
Controls auditory information and preserves the order n which information arrives
It’s capacity of the ‘loop’ is believed to be 2 seconds but can be maintained by articulatory control process
What does the phonological loop subdivide into?
Phonological store -(inner ear)- Holds information in speech based form for 1-2 seconds
Articulatory process -(inner voice)- Allows maintenance rehearsal (repeating sounds in a loop to keep them in working memory while they are needed)
What does the Visio-spatial sketchpad do?
It processes visual and spatial information (how things look and where they are)
Limited capacity of 3 or 4 objects (Baddley, 2003)
What did Logie (1995) subdivide the Visio-spatial sketchpad into?
The visual cache - which stores visual data
The inner scribe - which records the arrangement of objects in the visual field
When was the Episodic buffer added to the WMM?
In 2000 by Baddeley
What is the Episodic Buffer?
A temporary store of information, integrating the visual, spatial and verbal information processed by other stores and maintaining a sense of time sequencing - basically recording events (episodes) that are happening
-Can be seen as a storage unit for the Central Executive
-Has a limited capacity of around 4 chunks
-Links Working Memory to LTM and wider cognitive processes such as perception
Evaluation of the Working Memory Model?
:) - KF, 1970 - When he saw it himself he could recall the digits, but couldn’t when it was read out loud to him. Shows there are 2 different stores for visual and auditory information
:) - Baddeley et al, 1975 - showed that participants had more difficulty doing 2 visual tasks - tracking a light and describing the letter F - than doing both a visual and verbal task - both visual tasks compete for the slave system - means there must be a separate slave system that processes verbal input
:) - Braver et al, 1997 - During brain scan researchers found greater activity in left prefrontal cortex - activity increased as tasks got harder - shows that as demands of CE increase, it has to work harder to fulfil it’s function
:( - Baddeley - Cognitive psychologists suggest the central executive doesn’t really explain anything - needs to be more clearly specified than just being simply ‘attention’ - means WMM not fully explained
:( - Poor validity - Dual-task studies supporting the WMM are unlike tasks we perform in our everyday lives, and are carried out in highly-controlled lab conditions and so the the model may lack ecological validity
Who established that there is different types of LTM?
Endel Tulving (1985)
What are the 3 types of LTM?
Episodic memory
Semantic memory
Procedural memory
What is episodic memory?
- Our ability to remember events from our lives.
- These memories are ‘time stamped’ and you remember when they happened
- Will include several elements e.g. objects, people, place, behaviours
- Requires a conscious effort to recall episodic memories - you are aware you are remembering them
What is semantic memory?
- Contains our knowledge of the world
- Includes facts and knowledge of things such as the taste of an orange
- Not time-stamped - don’t remember when you learnt the meaning
- Less personal
- An example of declarative memory
What is procedural memory?
- Memory for actions, skills or basically how we do things
- Recall without a conscious awareness or a great deal of effort e.g. how to drive a car
- This is an example of an implicit memory ( knowing how )
Evaluation of types of LTM?
:) - Clinical evidence - Case studies of HM and Clive Wearing - procedural memories still intact - shows clearly that there must be different types of LTM - BUT difficult to generalise to others
:) - Tulving et al , 1994 - Ppts performed various memory tasks while their brains were scanned using a PET scanner - found that episodic + semantic memories were both recalled from an area of the brain but on different sides - physical evidence that different memories are stored in different locations
:( - Buckner and Peterson , 1996 - Other research links the left prefrontal cortex with episodic memories (not the right like Tulving) - this challenges any neurophysiological evidence to support types of memory as there is poor agreement
:) - Belleville , 2006 - Real life app - Demonstrated that episodic memories could be improved in older people who had mild cognitive impairment - you can work on specific parts of memory to improve it so there must be different types of memory - gives Tulving’s research validity
:( - Cohen and Squire , 1980 - argue that semantic and episodic memories are stored together in one LTM store that they call declarative memory i.e. memories that can be continuously recalled
Define interference
When two pieces of information conflict with each other, resulting in the forgetting of one or both OR some distortion in the memory
Proposed theory of forgetting for LTM
What are the 2 types of interference?
Proactive interference
Retroactive interference
What is proactive interference?
When an older memory interferes with a new one
e.g. teacher has learned so many names in the past he has difficulty remembering the names of his current class
What is retroactive interference?
Occurs when a newer memory interferes with an older one
e.g. teacher has learned so many names this year that she has difficulty remembering the names of students last year
What happens to interference when memories are similar?
Interference is worse
What was McGeoch and Mcdonald’s (1931) study on retroactive interference?
- They studied retroactive interference by changing the amount of similarity between the two sets of materials.
- Ppts had to learn a list of words until they could remember them 100% accurately.
- They then learnt a new list
- Most similar material (synonyms) produced the worst recall which shows interference is strongest when memories are similar
Evaluation of interference?
:) - McGeoch and Mcdonald - Show both types of interference are very likely to be common ways we forget info from LTM - lab experiments are controlled and thus give us confidence that interference is a valid explanation for forgetting
:) - Baddeley and Hitch , 1977 - Asked rugby players to recall the names of teams played earlier in the season. Recall was dependent on the number of intervening games - INTERFERENCE - Shows it can be applied in some real-world situations , increasing the theory’s validity
:) - Coenen and van Luijetelarr , 1997 - drug studies - showed that forgetting can be due to interference
:( - Artificial materials - much greater chance that interference will be demonstrated in the lab than in real-life situations - stimulus materials in most studies are lists of words
:( - Another explanation: Decay - Forgetting may occur as a result of the automatic decay or fading of the memory or memory trace
:( - Tulving and Psotka , 1971 - Interference is a temporary loss of accessibility to material that is still in LTM, and can be overcame with cues
What is retrieval failure?
The reason we forget is due to insufficient cues
What is the Encoding Specificity Principle (ESP) ?
” The greater the similarity between the encoding event and the retrieval event, the greater the likelihood of recalling the original memory “
What is a cue?
A ‘trigger’ of information that allows us to access a memory
What are the 2 types of cue-dependent forgetting?
Context-Dependent Forgetting (External environmental cues)
State-Dependent Forgetting (Internal cues)
What is Godden and Baddeley’s (1975) experiment on context-dependent forgetting?
- Divers learned a list of words either underwater or on land and were asked to recall the words either underwater or on land
- 4 conditions
- When their study environment matched their recall environment they were able to recall more words
- The external cues available at learning were different from the ones at recall and this led to retrieval failure
What is Carter and Cassaday’s (1988) experiment on state-dependent forgetting?
- Gave anti-histamine drugs to their participants which had a mild sedative effect making the participants drowsy.
- Creates an internal physiological state different from the ‘normal’ state of being alert and awake
- Ppts had to learn lists of words + passages from prose and then recall - 4 conditions
- In conditions where there was a mismatch between internal state at learning and recall, performance on the memory test was significantly worse
- When cues are absent there is more forgetting
Evaluation of retrieval failure
:) - Supporting evidence - Baddeley and Hitch (1975), Carter and Cassady(1998), Michael Eysenck(2010) - increases the validity of the explanation, especially as they were in highly controlled lab settings
:) - Baddeley - Real life applications e.g. entering a room and forgetting why you went into there and then remembering when you return to the previous room
:( - Baddeley, 1997 - Argues that context effects are not actually very strong- especially in real life as different contexts have to be very different before an effect is seen - suggests retrieval failure lacks real life application
:( - Godden and Baddeley, 1980 - Replicated underwater experiment but used recognition test - when recognition was tested, there was no context-dependent effect - shows the presence or absence of cues only affects memory when you test it in a certain way
:( - Problems with the Encoding Specificity Principle - unfalsifiable
What is eyewitness testimony?
The ability of people to remember the details of events, such as accidents and crimes, which they themselves have observed
Who conducted research into leading questions?
Elizabeth Loftus and Palmer (1974)
What was aim and method of Loftus and Palmer’s research?
Aim: To see if asking leading questions affect the accuracy of recall
Method: Participants we’re shown films of car accidents. Some were asked ‘how fast was the car travelling when it hit the other car’, whereas others where asked ‘how far was the car travelling when it smashed the other car’.
There were 5 groups: smashed, hit, contacted, bumped, collided
How did Loftus use a leading question in her experiment?
The question suggests a speed in which the car was going
What were the results of Loftus’ and Palmer’s study (1974)?
verb mean speed estimate
smashed: 40.8
collided: 39.3
bumped: 38.1
hit. : 34.0
contacted: 31.8
Evaluation of palmer and loftus’ experiment?
:) - real life application
:) - highly controlled- extraneous variables minimised
:( - people may have had different experience with car crashes
:( - low ecological validity as it was on a video not in real life
What reasons do leading questions affect eyewitnesses testimony?
Response-Bias explanation
Substitution explanation
What is the response-bias explanation for the affect of leading questions?
When the wording of the question has no real effect on the participant’s memories. It just influences how they decide to answer.
What is the substitution explanation for the affect of leading questions?
When the wording of a leading question actually changes a participants memory.
What was the one critical question during loftus and palmer’s second experiment and what were the results?
“Did you see the broken glass?”
results:
-when the word was smashed : 16yes 34 no
-when the word was hit : 7yes and 43no -control- 6yes and 44no
What is post-event discussion (relating to misleading information)?
- When co-witnesses to a crime discuss it with each other their eyewitness testimonies may become contaminated
- This is because they combine misinformation from other witnesses with their own memories
Who researched into post-event discussion and what was their method?
Gabbert et al (2003)
-Participants in pairs - each participant watched a video of the same crime but at different points of view
- Each participant could see elements in the event that the other could not
- Both participants then discussed what they had seen before before individually completing a test of recall
What were the results and conclusion of Gabbert’s study on post-event discussion?
Results:
-71% of the participants has mistakenly recalled aspects of the event that they did not see in the video but had picked up in the discussion
- control group- 0%
Conclusion:
Witnesses often go along with each other, either to win social approval or because they believe the other witnesses are right and they are wrong. This is called memory conformity.
Evaluation of misleading information?
:) - Useful real-life application - Loftus believes that leading questions can have such a distorting effect on memory that police officers need to be very careful about how they phrase their questions when interviewing eyewitnesses
:( - Tasks used in research are artificial - Loftus and Palmer- clips of car accidents - not real accident witnessed - lack ecological validity
:( - Individual differences - older people less accurate than young people when giving eyewitness reports + age groups more accurate when identifying people of their own age group - own age bias
:( - Demand characteristics - Zaragoza and McCloskey (1989) - participants do not want to let the researcher down and want to appear alert and attentive - influences accuracy
:( - Consequences of EWT - Foster et al (1994) - what you remember as an eyewitness can have some very important consequences in the real world, but the same is not true in research studies
Why does anxiety negatively effect recall?
It creates physiological arousal in the body which prevents us from paying attention to important cues so recall is worse
What did Johnson and Scott (1976) find?
- low anxiety cond. - man carrying a pen with grease on his hands
- high anxiety cond. - man holding paper knife with blood on his hands
Participants later picked out the man from 50 photos : 49% of ppts identified man carrying pen , 33% identified the man with the knife.
The tunnel theory of memory suggests that a witness’ attention narrows to focus on a weapon, because it is a source of anxiety = weapon focus
Why does anxiety positively effect recall?
- Triggers fight or flight which increases our alertness and improves our memory for the event as we become more aware of cues in the situation
What did Yuillie and Cutshall (1986) find?
- Real-life shooting - 21 witnesses and 13 agreed to take part in study
- Interviewed 4-5 months after incident - compared with og police interviews at the time
Witnesses were very accurate in their accounts and there was little change in accuracy after 5 months.
Ppts who reported the highest levels of stress on the 7 point scale were most accurate (88% compared to the less stressed group which was 75%)
Who developed the inverted-u theory?
Yerkes and Dodson (1908)
What does the inverted-u theory suggest?
- lower levels of anxiety produce lower levels of recall accuracy
- memory becomes more accurate as the level of anxiety experienced increase
- BUT there is a point where the optimal level of anxiety is reached and if anxiety increases- recall dramatically declines
Evaluation of Anxiety in EWT?
:( - Weapon effect may not be relevant - Pickel (1998) found that the weapon effect is due to unusualness rather than anxiety/threat - as the chicken reduced recall also
:(- Field studies can lack control - Researchers usually interview real-life eyewitnesses - have no control over discussions with others or what they have seen in the media - extraneous variables may be responsible for accuracy of recall
:( - Ethical issues- May subject people to emotional harm purely for the purpose of research - better to interview real life situations so there is no need to create artificial scenarios
:( - Inverted-u too simplistic - anxiety is hard to operationalise
:( - demand characteristics in lab studies of anxiety
:) - Research support- Christianson and Hubinette’s finding shows that anxiety does not reduce the accuracy of recall and may even enhance it giving the theory validity
4 Characteristics of the cognitive interview?
1.Report everything
2.Reinstate the context
3.Reverse the order
4.Change perspective
Evaluation of the cognitive interview?
:) - Research support - Kohnken et al (meta-analysis) indicates there are real practical benefits to CI
:( - Increases inaccurate information recalled - should be used with caution
:( - Not all elements are equally effective/useful - e.g. report everything context reinstatement produced better recall than any of the other conditions - maybe CI is not credible
:( - Time-consuming and requires specific training
What was Peterson and Peterson’s (1959) study into duration?
→ Wanted to see if rehearsal was necessary to hold information in the STM store.
→ Participants given Trigrams - sets of 3 letters to remember, but were immediately asked to count backwards in 3’s out loud for 3,6,9,12,15,18 seconds.
→ This was done to prevent rehearsal and ppts. We’re then asked to recall the 3 letters (Triagram) in the correct order.
→ Participants had forgotten virtually all the information after 18 seconds.
