Memory Flashcards
The multi-store model of memory
− Three types of memory have been identified: the sensory register, short-term memory + long-term memory, these are generally considered to be memory structures or stores of information
− Sensory register – this is not under out control but is an automatic response to the reception of sensory information (input from our senses) + is the first storage system within the MSM, all memory must pass through the SR first, stores encoded sensory input
− Short-term memory – this is our present conscious experience where information is processed from the SR through attention + rehearsal, information is stored temporarily + it is thought to have limited capacity + duration, stores mainly acoustic or visual info
− Long-term memory – information can be stored permanently, it is thought to have unlimited duration + capacity if information has been processed sufficiently, the complexity of LMT has led to different types of memory being identifies e.g. semantic + procedural
The multi-store model of memory: Coding in the SR
− The SR processes sensory information received from the sense organs e.g. eyes, ears, nose
− Information is stored in a raw, unprocessed from with separate sensory stores from different sensory inputs:
→ Echoic store – auditory info e.g. music
→ Iconic store – visual info e.g. sunlight
→ Haptic store – tactile info e.g. pain
→ Olfactory store – smell e.g. cut grass
− Crowder found that the SR only retains info in the iconic store for a few milliseconds but for 2-3 secs within the echoic store which supports the idea of sensory info being coded into different sensory stores (it also suggests that they have different durations)
The multi-store model of memory: Capacity of the SR
− The capacity of each store in the SR is very large with information in highly detailed form
− The fact that the SR has such a short duration makes it difficult to research its capacity as the information leaves the store so quickly making it hard to find out how much was stored initially
The multi-store model of memory: Duration of the SR
− All sensory memory stores have limited duration although the duration varies from store to store with different types of information decaying at different rates
− Walsh + Thompson found that the iconic sensory store has an average duration of 500 milliseconds which decreases as individuals get older
− Evolutionary advantages of the brief duration of the SR – people can focus on perceptual information with an immediate survival value, retaining non-useful information would compromise this
The multi-store model of memory: Baddeley
− Procedure:
→ 75 ppts were divided into 4 groups + were presented with ¼ word lists (consisting of 10 words)
→ List A: Acoustically similar (cat, mat, sat)
→ List B: Acoustically dissimilar (pit, day, cow)
→ List C: Semantically similar (big, huge, tall)
→ List D: Semantically dissimilar (hot, safe, foul)
→ STM – ppts were then given a list containing the original words in the wrong order, their task was to rearrange the words in the correct order
→ LTM – the procedure was the same but there was a 20 min interval before recall during which ppts performed a distractor task to prevent rehearsal
− Findings:
→ STM – ppts given list A (acoustically similar) performed the worst with recall of only 10% they confuses similar sounding words e.g. cap instead of cat, recall for the other lists was comparatively good at bet. 60%-80%
→ LMT – ppts given list C (semantically similar) performed the worst with a recall of only 55% they confused similar meaning words e.g. big instead of huge, recall for the other lists was bet. 70%-85%
− Conclusions:
→ STM – Baddeley concluded that STM is encoded on an acoustic basis due to the acoustic confusion
→ LTM – Baddeley concluded that LTM is encoded on a semantic basis due to the semantic confusion
The multi-store model of memory: Coding in the STM
− Information arrives from the SR in its original form e.g. a sound or image + is then encoded (entered into STM) in a form that STM can more easily deal with
− Beddeley’s research suggests that encoding in STM is acoustic however other research has suggested information can also be encoded visually in STM
− Bradimonte et al found evidence to support this
→ They presented ppts with 6 line drawings of familiar objects + asked them to memorise each one
→ It is though that the drawings were encoded acoustically in terms of the objects name so when ppts were asked to form a mental image of the drawing + subtract a part of it to reveal a different object they were lea able to name the image than those ppts who were asked to memories that drawings whilst repeating the meaningless chant ‘la-la-la’ (which could have supressed acoustic encoding thus encouraging visual encoding of the information)
The multi-store model of memory: Capacity of STM
− Limited
− Miller’s ‘magic number 7’ – 7+/-2 items (5-9 items)
− Tested sing he serial digit span technique
− Capacity can be enhanced through chunking
The multi-store model of memory: Duration of STM
− Limited
− Less than 30 seconds
− Peterson + Peterson – ppts only recalled about 2% of trigrams when there was an 18 sec time interval compares to about 90% after a 3 sec interval
− Duration can be extended by rehearsal (repetition) of the information which is done long enough can result in the transfer of information to the LTM
The multi-store model of memory: Coding in the LTM
− Mainly semantic (by meaning)
− Baddeley – recall was worse for semantically similar worse than semantically dissimilar words but recall was the same for acoustically similar + acoustically dissimilar words suggesting the encoding is semantic due to semantic confusion
The multi-store model of memory: Capacity of LTM
− Potentially unlimited – information may be lost due to decay + interference but these losses do not occur due to lack of capacity in LTM
− Clive Wearing – demonstrated the existence of the procedural memory
→ :) Clive Wearing was unable to lay down any new long term memories after his hippocampus was destroyed by a viral infection suggesting that there is a separate short-term + long-term memory store in the brain
→ :( However Clive was still able to slight-read + play complex pieces on the piano suggesting that this procedural memory was intact which cannot be explained by the multi-store model of memory as it does not recognise different types of long-term stores
The multi-store model of memory: Duration of LTM
− Potentially a life time
− Items in LTM have a longer duration if originally well coded + certain LTMs seem to have a longer duration e.g. those based on skills rather than facts
− Material in STM needs to be rehearsed in order to be retained however information in LTM does not have to be continuality rehearsed to stay in the store
The multi-store model of memory: Barrack et al
− Procedure:
→ Investigators tracked down graduates from a high school in America over a 50 yr. period
→ 392 graduates were shown photos from their high school yearbook
→ Recognition group – for each photo ppts were given a group of names + asked to select the name that matched the photo
→ Recall group – ppts were simply asked to name the ppl in the photos without being given a list of possible names
− Findings:
→ In the name-matching (recognition) condition ppts were: 90% accurate after 14 yrs., 80% accurate after 25 yrs., 75% accurate after 34 yrs. + 60% accurate after 47 yrs.
→ In the recall group ppts were not as successful: 60% accurate after7 yrs. + less than 20% accurate after 47 yrs.
− Conclusion: Ppl can remember certain types of information for a life time, LTM appears to be better when measured by recognition tests than by recall tests
The multi-store model of memory: Research
− The serial position effect: Glanzer + Cunitz – ppts tended to recall the words from the beginning of a word list (primary effect) + from the end of the list (recency effect) rather than the middle
→ Primary effect – words at the beginning are rehearsed + transferred to LTM
→ Recency effect – these words remain in the STM prior to recall
→ This suggests that STM + LTM are separate stores
− Research has found that the prefrontal cortex is active when individuals are working on a task in immediate (i.e. short-term) memory (Beardsley) BUT the hippocampus is active when LTM is engaged (squire et al) – this further supports the idea that STM + LTM are separate stores in that it suggests they are located in different areas of the brain
− The case of H.M. supports + challenges the multi-store model of memory
→ The fact that H.M. was unable to form any new long term memories after the removal of his hippocampus suggests that there is a separate short-term + long-term store
→ However H.M. as able to acquire new skills suggesting that his procedural memory was intact – this cannot be explained by the multi-store model of memory as Atkinson + Shiffri view the LTM as a unitary store
Evaluation of the multi-store model of memory: Reductionist :(
− The model had been criticised for being too reductionist + inflexible to explain the entire memory system
→ It is reductionist because it reduces the complex nature of memory down to a simple set of ideas
→ It is an oversimplification of the memory structures + processes
→ E.g. it doesn’t explain the processes involved in encoding – there is too much emphasis on the structures eh SR, STM, LTM
→ It fails to recognise different types of long term memory e.g. procedural + episodic (as demonstrated by H.M. + Clive Wearing)
Evaluation of the multi-store model of memory: STM relied on LTM :(
− STM relies on LTM – this is not recognised by the model as it views the STM + LTM as independent stores, information may flow backwards from LTM
→ Ruchkin et al – STM is the party of the LTM that is activated when necessary
Evaluation of the multi-store model of memory: Rehearsal may not be the only way to commit memory to LTM :(
− Rehearsal may not be the only means by which to commit memories to the LTM
→ Information might be transferred to the LTM because of its distinctiveness or significance to the person (Eysenck)
→ Flashbulb memory – a highly detailed exceptionally vivid long-term memory of the moment + circumstance eh when you were, who you were with, during emotionally arousing or meaningful events (e.g. 9/11)
Evaluation of the multi-store model of memory: Case studies :(
− The case study of K.F. challenges the STM as a single (unitary) store as does the working memory model
− Evidence (H.M., Clive Wearing) has also suggested that there are different types of LTM e.g. declarative, episodic, procedural + that this isn’t a single store as the multi-store model would suggest
The working memory model
− Baddeley + Hitch proposed an alternative model to explain the short term memory
− They rejected Atkinson + Shiffrin’s ideas about STM being a unitary store – they argued that it was more complex than simply being a temporary store involved in transferring information to LTM
They saw STM as an active store – holding several pieces of information while they were being worked on
Central executive - episodic buffer - phonological loop/visuo-spatial sketchpad - LTM
The working memory model: Central executive
− The most important component
− It controls attention i.e. it receives information from the sense organs (e.g. ears + eyes) + decided what to attend to (i.e. filters incoming information)
− It plays a key role in directing information to + processing information from the ‘slave systems’ + LTM
− It is involved in problem solving + decision making
− It had a limited storage capacity so attention is limited at times – it can only effectively cope with one strand of information at a time
The working memory model: Phonological loop
− It has limited capacity
− It processes speech-based sounds for brief periods
− It consists of two parts:
→ Phonological/primary acoustic store (inner ear) – stores acoustically coded items e.g. words recently heard
→ Articulatory process (inner voice) – allows sub-vocal repetition (rehearsal) of items stored in the phonological store
The working memory model: Visuo-spatial sketchpad
− Stores/processes visual + spatial information (inner eye) + the relationship bet. them i.e. what items are+ where they are located
− It helps individuals to navigate around + interact with their environment
− It manipulated mental images
− It has a limited capacity
− Visual cache – stores information about form + colour
− Inner scribe – deals with spatial + movement information e.g. body movements + rehearses + transfers information in the visual cache to the central executive
The working memory model: Episodic buffer
− As addition storage system
− It binds together information from the different components into chucks/episodes including information from LTM e.g. recalling a scene from a movie (visual + verbal information)
− It has limited capacity BUT can potentially hold more than each of the two slave systems
The working memory model: The processing of visual + verbal tasks
− Baddeley proposed that because the STM consists of several different components that are able to work independently of one another that is therefore possible to complete a visual + verbal task simultaneously e.g. watching a film/TV which would tie up different slave systems
The working memory model research: Baddeley et al :)
− Baddeley et al
→ Procedure: ppts had to track a moving stop of light whilst either imagining the letter ‘F’ + classifying the angles (yes = include bottom/top line of letter, no = if it did not) or completing a verbal task – they therefore compared ppts doing two visual tasks against those doing a visual + verbal task
→ Findings: ppts found it more difficult to track the spot of light whilst classifying the angles of the letter ‘F’ because both tasks involved the visuo-spatial sketchpad which has a limited capacity – however those doing the visual + verbal task found it less difficult to complete both simultaneously because they involved both the VSS + PL therefore suggesting the VSS is a separate slave system
The working memory model research: Brain damage patients :)
→ KF – damage to phonological loop following a motorcycle accident led to difficulty processing auditory information BUT not visual information
→ LH – performed better on spatial then visual imagery tasks supporting the view that there are separate visual + spatial systems
→ They provided evidence for the existence of the two main slave systems as well as the sub-systems within the visuo-spatial sketchpad
→ :( The process of brain injury is traumatic which may in itself change behaviour causing a person to perform worse in certain tasks – this therefore makes it difficult to generalise the findings to others because of the unique characteristics of each individual (they lack population validity)
The working memory model research: PET scans
− PET scans show that different areas of the brain activated when doing verbal + visual tasks which suggests that the phonological loop + visuo-spatial sketchpad are separate store as reflected in the biology of the brain – PET scans have also shown activation in the left hemisphere of the brain with visual tasks + activation in the right hemisphere with spatial information which supports the existence of the visual cache + inner scribe
Evaluation of the working memory model: Benefits over the multi store model of memory :)
− One advantage of the WMM compared to the MSM is that it explains how it is easier to do two tasks that are different (e.g. verbal + visual – tested using the dual-task technique) than two tasks that are similar (e.g. two verbal tasks)
→ Each slave system had a limited capacity so there is only so much information they can process at any one time
→ Two similar tasks would place too many demands on the same slaves system thus making it more difficult to process the information resulting in a slower processing speed
Evaluation of the working memory model: The central executive is a vague concept :(
− Central executive – a vague concept
→ There are problems in specifying the precise function of the central executive – it isn’t clear what it is or how it works
→ Research into this component is lack despite it supposedly being the most important component
→ Critics dispute the idea of a single central executive +instead argue that there are probably several components
→ The central executive is perhaps better understood as a component controlling the focus of attention rather than a memory store like the PL + VSS
Evaluation of the working memory model: Only concerns STM :(
Working memory only concerns STM so it is not a comprehensive model of memory (as it does not include SM or LTM)
Types of LTM
− Just as the working memory model demonstrates different type of short-term memory research also indicates that existence of different types of long-term memory each with a different function + a different area of the brain associated with its use
Types of LTM: Episodic LTM
− This is the types of memory that provide us with an autobiographical record of our person experiences e.g. birthdays, wedding etc.
− The strength of episodic memories is influenced by the emotions present at the time a memory is coded e.g. traumatic events are often recalled well due to their high emotional content
− The strength of these memories is also influenced by the degree of processing of information at coding – highly processed episodic events are recalled more easily
− It is thought that this type of memory helps individuals to distinguish the difference bet. real + imagined events
− Episodic memories are associated with several areas of the brain:
→ The prefrontal cortex is associated with the initial coding of episodic memories
→ Consolidation (strengthening) of these memories is associated with the neocortex
→ Memories of different parts of an event are located in the different visual, auditory, olfactory etc. areas of the brain but are connected together in the hippocampus to create memory of an episodic rather than its remaining a collection of separate sensory memories
Types of LTM: Episodic LTM - Tulving
− Procedure:
→ 6 volunteers were injected with small amounts of radioactive gold + scanned to detect its location with a gamma ray detector
→ Each ppts performed 8 successive trails each lasting 80 secs, involving 4 semantic + 4 episodic topics in randomised order
→ Individual trails were separated by 2 mins of rest each – a ppts would lie face up on a couch with their eyes closed + indulge in either episodic or semantic LTM retrieval, the retrievals involved silent mental thought rather than physical stimulation or recording of behaviour, ppts decided what topics they would think about
→ At a signal from a researcher a ppts would start thinking about a topic
− Findings:
→ 3 ppts produced inconclusive data
→ Ppts showed consistent differences in cortical blood flow patterns bet. semantic + episodic thinking – there was greater activation in the frontal lobes activation in the frontal lobes of the cortex during thinking about episodic memories + greater activation in the presterior region when retrieving semantic information
− Conclusion:
→ Episodic + semantic LTMs appear to involve different brain areas + thus are separate forms of LTM
→ The fact that episodic + sematic memories involves different brain areas suggests a biological bias to difference in LTM
Evaluation of Episodic LTM (types of LTM): Unclear difference bet. episodic + semantic LTM :(
P: The extent to which episodic + semantic memory systems differ in unclear – although different brain areas are involved there is also a lot of overlap bet. the two systems
E: Semantic memories often clearly originate in episodic memory (e.g. your memory of being taught something is episodic but what you learn may be semantic)
C: It may be the case that an episodic memory can transform into a semantic memory however we cannot be certain whether this is what occurs
Evaluation of Episodic LTM (types of LTM): Scientific techniques :)
Research often uses advanced scientific techniques e.g. brain scans which are objective therefore increasing the reliability
Types of LTM: Semantic LTM
− This type of memory is also explicit like episodic memory + contains all knowledge + facts that an individual has learned e.g. capital cities + names of colour
− The strength of semantic memories is positively associated with the degree of processing occurring during coding
− They often appear to be underpinned by episodic memories as there is an episodic memory of when the memory was acquired (the experience of learning it)
− Over time there appears to be a gradual shift towards semantic memories with the knowledge/understanding becoming more divorced from the event or experience it was learned from
− There are disagreement over the parts of the brain associated with semantic memory it seems that the hippocampus is involved but evidence also suggests that involvement of several other parts of the brain, coding is mainly associated with the frontal + temporal lobes
Types of LTM: Semantic LTM - Research
− Tulving
− Vicari et al:
→ CL an 8 yr. old girl who suffered from brain damage from the removal of a tumour
→ She had deficiencies in her episodic LTM functions particularly creating new episodic memories – she was able to create + recall semantic memories
→ Therefore suggesting that episodic + semantic memory are separate systems using different brain areas with the hippocampus associated with episodic memories + the perithical cortex with semantic LTM
Evaluation of Semantic LTM (types of LTM): Unclear difference bet. episodic + semantic LTM :(
As is the case with evaluating episodic memory – there is some debate about the difference bet. semantic + episodic memory
Evaluation of Semantic LTM (types of LTM): May not be a single type of memory :(
P: It may be the case that semantic memory is not a single type of memory
E: The fact that the damage to different areas of the brain can affect semantic memory supports the idea that semantic memory abilities are spread throughout brain structures
C: Also suggesting that semantic memory may consist of several interrelated memory abilities + therefore not be a single type of memory
Types of LTM: Procedural memory
− This type of memory is a form of implicit memory that permits individuals to reform learned tasks with little conscious thought e.g. riding a bike + talking
− Although seemingly easy to do procedural LTMs are difficult to explain in works (so are classes as ‘non-declarative)
− Many procedural LTMs are acquired early in life – they are often concerned with the learning of important motor skills e.g. walking
− Procedural LTM is also involved in language helping individuals to speak automatically using grammar + syntax without having to think about how to
− This shows that procedural + semantic memories are likely to work together
− As procedural memory does not require conscious thought it permits people to simultaneously perform other cognitive tasks that require attention (e.g. you can walk + hold a conversation at the same time)
− Mainly associated with the primary motor cortex, cerebellum + prefrontal cortex
− Unlike the explicit forms of LTM procedural memory does not require the hippocampus to function
Types of LTM: Procedural memory - Research
− The case of Clive Wearing:
→ Clive Wearing was unable to form any new long-term memories after his hippocampus was destroyed by a viral infection however he was still able to sight read + play complex pieces on the piano
→ This suggests that his procedural memory was intact providing support for the idea that there are different types of long-term stores
Evaluation of procedural memory (types of LTM): Case study of HM :)
P: The case study of HM provided support for procedural memory
E: His ability to form new LTMs was severely affected by the destruction of his hippocampus but he retained his pre-existing LTM – although he appeared unable to form new explicit (declarative) memories he retained the ability to form new procedural memories
C: e.g. he was able to learn how to draw a figure by looking at its reflection in a mirror (mirror drawing) – this is a procedural memory, however he had no memory that he had learned this (an episodic/semantic memory)
Evaluation of procedural memory (types of LTM): Lack of research :(
P: There is a general lack of research that can demonstrate which areas of the brain are associated with procedural memory
E: What is needed are case studies of people with brain damage that affects procedural memory but not explicit memory (semantic + episodic memory)
C: However such cases are rare
Forgetting
− Forgetting – the failure to retrieve memories with explanations varying bet. those that see information as no longer within storage + explanations that see forgetting as a failure to access stored information – a person’s loss if the ability to recall or recognise something that they have previously learned
Explanations for forgetting: Interference theory
− This theory sees forgetting as being due to information in the LTM becoming confused with or disrupted by other information during coding leading to inaccurate recall
− Proactive interference (PI):
→ Works forwards in time
→ Occurs when information stored [previously interferes with an attempt to recall something else
→ E.g. the memory of an old phone number may disrupt an attempt to recall a new phone number
− Retroactive interference (RI):
→ Works backwards in time
→ Occurs when new information disrupts information that is already stored in the long term memory
→ E.g. the new memory of a new car registration plate disrupts the memory of the old registration plate
Schmidt et al (Explanations for forgetting: Interference theory)
− Procedure:
→ 211 ppts (11-79 yrs.) given a map of the neighbourhood where they had gone to school with street names replaced with number is + asked to remember as many as possible
→ Other info was collected with a questionnaire e.g. if they moved house, where they lived + for how long
→ The amount of retroactive interference was assessed by the number of time ppts moved (learnt new sets of street names
→ This measure was variable – 25% of ppts had never moved while 1% moved over 40 times
− Findings: There was a positive association bet. the number of times ppts moved house outside of the neighbourhood + the number of street names forgotten
− Conclusion: Findings suggest that learning new street names when moving house makes recalling older street names harder – retroactive interference does seem able to explain forgetting in real life situations
Schmidt et al (Explanations for forgetting: Interference theory) evaluation
→ :) Extraneous variables that may have confused results – those who played in the neighbourhood or walked to school would probably have learnt street names to a better degree
→ :( Methodology used showed it is possible to conduct research on retroactive interference in real-life settings – could be easily adapted to test the influence of proactive interference too
Evaluation of interference theory (explanations for forgetting): Only explains when two pieces if info are similar :(
− This explanation only really explains forgetting when the two pieces of information are similar to each other (e.g. two names or phone numbers) – it can’t explain all incidence of forgetting, it’s not particularly common to be presented with two very similar pieces of information so this theory cannot explain forgetting in the majority of real-life settings
Evaluation of interference theory (explanations for forgetting): Research support - Braddeley + Hitch :)
− Evidence support comes from Braddeley + Hitch who got ppts who had played a varying number of rugby games to remember as many of the teams they had played against as possible, interference theory was tested by assessing how recall was affected by the number of games played – it was found that forgetting was due more to the number of games played supporting inference theory
Evaluation of interference theory (explanations for forgetting): Highly controlled research :)
Much research into the interference theory of forgetting is conducted under highly controlled conditions this means that the results have high internal validity + it is easier to establish a cause-effect relationship – :( BUT because they are artificial (tasks) taking place in an lab some suggest they are not very realists, it doesn’t really explain how we use our memory (+ how we forget) in everyday situations
Evaluation of interference theory (explanations for forgetting): We must make inferences :(
Although there is strong evidence from research that interference is a real effect these studies do not + cannot identify the cognitive processes at work – we must make inference about what is happening within the memory to cause the disruption, it could be argued that this reduced the validity of the theory as there is no direct empirical evidence
Explanations for forgetting: Cue dependent forgetting
− Occurs when information is still in the LTM but cannot be accessed
− This theory sees recall (remembering) as being dependent upon retrieval cues – retrieval cues are things that serve as a reminder + aid recall, they may meaningfully link to the material to be remembered or they may not be meaningfully linked e.g. environment cues (a room) or cues related to your mental state (emotions that you felt at time of encoding)
− Tulving proposed the encoding specificity principle – recall is likely to be poor if the context of recall is different to how it as during coding
− It also suggests that effectiveness of a retrieval cue is dependent upon:
→ How overloaded it is (the fewer number of items associated with it the more effective the cue is)
→ How deep the processing of the cue was
→ How well the cue fits the information that is associated with it
Explanations for forgetting: Cue dependent forgetting - Context-dependent failure
− This occurs when the external environment is different at recall from where the information was originally learned
− It is proposed that the environment is encoded with the information you learn + then can act as a trigger for recall
− Research – Godden + Baddeley:
→ Asked scuba divers to learn material either in dry land or underwater
→ Recall was found to be poorer when they were testing in a different context to coding (different to where they’d learned the info)
→ This supports context-dependent forgetting because there was a lack of context dependent cues
Explanations for forgetting: Cue dependent forgetting - State-dependent failure
− This occurs when internal retrieval cues (either your physical or emotional state) are different at the point at which information is learned + then recalled
− Research – Overton:
→ Ppts learned material when drunk or sober
→ They had to recall the material – ½ were in the same state as they were when they learned the material (e.g. drunk both times or sober both times) ½ were in a different state (e.g. drunk then sober or vice-versa)
→ It was shown that those who were in the same state at coding + recall performed better in the recalled test
Explanations for forgetting: Cue dependent forgetting - Category headings as retrieval cues
− Category headings often act as retrieval cues + help ppts to remember more words compared to free-recall
− Research – Tulving + Pearlstone:
→ Gave ppts a list of 48 words to learn organised into 12 categories of 4 words each – at the top of each category was a one word heading (e.g. fruit) + ppts were instructed to learn the words but told they didn’t need to learn the headings
→ The ppts were tested ½ were presented with the category headings + ½ without
→ Those presented with the headings remembered more words – presumable as the headings acted as cues to trigger the recall of the 4 words
Evaluation of cue dependent forgetting (explanations of forgetting): Highly controlled research :)
Much research into the cue dependent explanation of forgetting is conducted under highly controlled conditions this means that the results have high internal validity + it is easier to establish a cause-effect relationship – BUT because they are artificial (tasks) taking place in an lab some suggest they are not very realists, it doesn’t really explain how we use our memory (+ how we forget) in everyday situations
Evaluation of cue dependent forgetting (explanations of forgetting): In line with the levels of processing theory :)
The idea of retrieval cues is in line with the levels of processing theory – levels of processing theory (LOP) suggests that information that is deeply processed at coding (e.g. how much thinking + what type of thinking occurs when processing the info) is less likely to be forgotten, this is because more links + associations are created bet. items in the LTM providing more retrieval cues
Evaluation of cue dependent forgetting (explanations of forgetting): Real world application :)
Real-world applications: one practical use of the knowledge + understanding gained by psychologists about cue-dependent forgetting is that of police reconstructions of unsolved crime – the aim is to jog the memory of witnesses by recreating the context of the incident through the use of retrieval cues, this shows that the theory has successful real world applications
Evaluation of cue dependent forgetting (explanations of forgetting): Godden + Baddeley (divers) :(
− Godden + Baddeley’s findings only occurred when the divers had to free-recall the items they had learned – when asked to recognise the words they had been shown there was no context-dependent effect (being in the same underwater/on-land environment as where they learned the words did not reduce the number forgotten), this suggests that cue dependent forgetting can’t explain all forms of forgetting
Eyewitness testimony (EWT)
− EWT is the evidence provided by a person who witnessed an event e.g. a crime or an accident
− Stages in EWT:
1. Encoding of information in LTM
2. Retention of information – memories may be lost of become distorted during retention
3. Retrieval of information – accuracy may be affected by the questioned asked
Eyewitness testimony (EWT): Misleading information
− Leading questions: questions that increase the likelihood that an individual’s schema will be influenced to give a desired answer
− Post-event discussion: concerns misleading information being added to a memory after the event had occurred – with research indicating that false memories can be stimulated by misleading post-event experiences/discussions
Eyewitness testimony (EWT): The influence of schemas in memory
− Bartlett argued that memories are ‘reconstructions’ of events influenced by active schemas
− Schemas can affect the reliability of memory because witnesses are reconstructing memories that may be biased by schema that are activated at the time or recall which can lead to false memories
Eyewitness testimony (EWT) + misleading information: Loftus + Plamer
− Procedure:
→ 45 students were shown 7 films of different road traffic accidents + asked a series of question about what they had seen in the films
→ The critical question asked was: “about how fast were the cars going when they ________ each other?”
→ Across the 5 groups the blank was filled in with different verbs: “contacted, collided, hit, smashed, bumped”
− Findings: As the intensity of the verb used in the key question increases so did the estimation of the speed of the cars e.g. contacted = 31.8 mean mph, hit = 34 mean mph + smashed = 40.8 mean mph
− Conclusion: Misleading information is the form of leading questions can affect memory recall of eyewitnesses + recall of misleading information is reconstructed with material from the original memory
Eyewitness testimony (EWT) + misleading information: Loftus + Plamer criticism
− Criticism: The study was a lab experiment centred on an artificial task (watch videos) + as such lack relevance to real life scenarios therefore lacking ecological validity – witnessing real car crashed would have much more of an emotional impact + thus would affect recall differently
Eyewitness testimony (EWT) + misleading informtion: Loftus + Plamer 2nd experiment (broken glass)
− Loftus +Palmer conducted a 2nd experiment to see if memory was distorted or changed by post event information:
→ A different set of ppts were divided into three groups + shown a film of a car accident + again they were asked how fast they thought the cars were travelling when they either “smashed” or “hit” (there was also a control group)
→ Ppts returned a week later + were asked if they saw any broken glass
→ The smashed group were more likely to say they saw broken glass - 16 from the smashed group said “yes” (they saw broken glass) compared to only 7 from the hit group
Eyewitness testimony (EWT): Blatantly incorrect info
− In a study by Loftus (1979) ppts were exposed to as et od slides depicting the theft of a large red purse from a handbag of which 98% correctly remembered in an immediate recall test
− When ppts were provide with an account where the purse was stated as being brown all but two of the ppts resisted this blatantly incorrect information + still correctly recalled the stolen purse had been red
− This suggest that memory is not easily distorted by blatantly incorrect information but it may be more easily influence by subtle + plausible misleading information
Eyewitness testimony (EWT): Post event discussion
− Gabbert el al put ppts in pairs + then showed them different videos of the same vent so that they saw different items – ½ of the pairs were then encouraged to discuss the event of the video before each partner individually recalled what they saw to the researcher
− A very high number of witnesses (71%) who had discussed the event went on to mistakenly recall items acquired during the discussion
Evaluation of research in the effects of misleading information on the accuracy of eyewitness testimony (EWT): Highly controlled conditions :)
P: Loftus’ research was conducted under highly controlled lab conditions
E: The risk of extraneous variable was therefore reduced
C: This increases the internal validity of the study + also makes it possible for other researchers to replicated her research to check the reliability of her findings
Evaluation of research in the effects of misleading information on the accuracy of eyewitness testimony (EWT): Real-life application (in the criminal justice system) :)
P: Loftus’ research has highlighted how unreliably eyewitness accounts can be
E: … which has been of benefit to the criminal justice system
C: There is now more awareness of the problems with relying too heavily on eyewitness account especially when there is no other evidence to corroborate the account
Evaluation of research in the effects of misleading information on the accuracy of eyewitness testimony (EWT): Artificial lab conditions :(
P: Loftus’ research was conducted under artificial lab condition e.g. use of video clips
E: These situation do not accurately represent real-life situations involving EWT because ppts may not take the experiment seriously or experience the same level of emotional arousal (anxiety) e.g. watching a real car crash would be more emotionally arousing
C: This therefore decreases the ecological validity of the study making it difficult to generalise the findings
Evaluation of research in the effects of misleading information on the accuracy of eyewitness testimony (EWT): Demand characteristics :(
P: Ppts in Loftus’ study were aware that they were being studies which may have led to demand characteristics
E: Therefore their behaviour may not have been entirely natural as they may have been behaving in such a way to please the experimenter
C: This potentially reduced the internal validity of the study thus reducing the validity of the findings
Evaluation of research in the effects of misleading information on the accuracy of eyewitness testimony (EWT): Ethical issues :(
P: Loftus’ research raises some important ethical issues
E: Loftus deliberately misled her ppts which raised the issue of deception – furthermore some studies used potentially distressful stimuli e.g. video clips of a car crash which raised the issue of psychological harm
C: This stimulus could be particularly distressing for these who have experience traumatic car accidents
The effect of anxiety on accuracy of EWT: Weapon focus
− The ‘weapon focus’ affect is the idea that if there is a weapon present then individuals may pay more attention to the weapon that peripheral details e.g. the appearance of the perpetrator, the presences of a weapon may also significantly increase levels of anxiety experienced
− The presence of a weapon is therefore thought to negatively affect an eyewitness ability to recall details about the culprit as it diverts their attention away from important aspects of the situation + narrows their focus of attention to the weapon
The effect of anxiety on accuracy of EWT: Loftus et al (1979)
− Procedure:
→ Ppts sat in waiting room + overheard either a …
a) Low key discussion in lab about equipment failure, a man then emerged holding a pen with greased hands (low anxiety condition)
b) Hostile exchange, sound of breaking glass + crashing chairs, a man then emerged holding a bloodied paperknife (high anxiety condition)
→ Ppts were then presented with 50 photographs + asked to identify the man
− Findings: Ppts were less accurate in identifying a man who had been seen earlier holding a bloodied paperknife (33%) compared with those who had seen the same man holding a pen (49%)
− Conclusion: The weapon may have distracted the ppts attention away from the appearance of the person holding it
The effect of anxiety on accuracy of EWT: Loftus et al (1979) evaluation
→ Loftus + Burns found that ppts were less accurate in recall when they saw a violent short film than those who watched a non-violent short film – this demonstrated support for Loftus (1987) as it shows that when ppl witness anxiety-provoking situations they are less likely to recall the event or the perpetrator accurately
The effect of anxiety on accuracy of EWT: Research using real life witnesses
−
Yuille + Cutshall interviewed 13 eyewitnesses to a real-life shooting involving the owner of the shop + an armed thief (the storeowner was wounded, the thief was shot dead) – found that accurate accounts were given months later + that those in closer proximity gave more accurate account this suggests that high levels of distress increase accuracy of EWT which challenges Loftus’ findings
− Foster investigated consequentiality + found that identification of the robber was more accurate for the group who thought they were witnessing a real event + told that their responses would influence the trail – suggesting that the consequence of identifying someone is an important factor with respect to accuracy of recall
− The Yerkes-Dodson inverted-U hypothesis – this model suggests that moderate levels of anxiety promote accurate recall
Evaluation of the effect of anxiety on accuracy of EWT: Inconsistency in research :(
− Inconsistency in research findings (lab studies vs real life study’s) – therefore it is somewhat unclear whether anxiety improves or decreases the accuracy of EWT
Evaluation of the effect of anxiety on accuracy of EWT: Weapon focus might not cause anxiety :(
− Weapon focus might not be caused by anxiety
→ Pickel suggested that the reduced accuracy of identification due to the presence of a weapon might actually be due to surprise rather than anxiety
→ To test this she arranged for ppts to watch a thief enter a hairdressing salon carrying scissors (high treat, low surprise), a handgun (high threat, high surprise), a wallet (low threat, low surprise) or a whole raw chicken (low treat, high surprise)
→ Indication was the least accurate in the high surprise conditions rather than the high treat conditions
→ This supports the criticism that weapon focus is due to surprise rather than anxiety
Evaluation of the effect of anxiety on accuracy of EWT: Ethical issues
− Ethical issues –ppts are fully informed + are deceived, potentially distressing situations which may cause high levels of psychological harm
Evaluation of the effect of anxiety on accuracy of EWT: Individual differences
Individual difference e.g. personality
Improving accuracy of EWT – The use of the cognitive interview
− Geiselman et al proposed the cognitive interview schedule which was designed to be used by police investigations to elicit more accurate information from eyewitnesses
− It consists of 4 techniques:
Stages of the cognitive interview: 1) Metal reinstatement of context
Mentally recreate the physical + psychological environment of the original incident – these act as contextual + emotional cues to retrieve memories
E.g. weather, smells, lighting, other ppl, emotions – “what was the weather like?”
Stages of the cognitive interview: 2) Report everything
Even if it seems minor of insignificant as this could trigger the recollection of another memory as memories are often interconnected
E.g. “please tell me everything that you can remember about the event, anything that pops into your head”
Stages of the cognitive interview: 3) Change of narrative order
Not necessarily starting at the beginning perhaps recalling it in reverse order or starting from the most memorable aspect (disrupts the effects that schemas have on recall)
E.g. “what is the very last thing you recall happening? What happened before that?”
Stages of the cognitive interview: 4) Change of perspective
Eyewitnesses are asked to imagine how the incident would have appeared to other witnesses present at the time (disrupts the effects that schemas have in recall)
E.g. “try to recall the incident from the perceptive of another person, describe what he/she would have seen”
Evaluation of the cognitive interview: Supporting research :)
− Geiselman et al (1985) found that the CI procedure generated more accurate, detailed memory than the SPI technique + interviews conducted under hypnosis suggesting that CI techniques are effective
− Kohnken et al found that there was an increases of 81% in the amount of accurate recall informational produced when using CI compared with standard interviewing techniques - however Cis also produced 61% more inaccurate info than the SPI, they also found that CIs generate more correct detail when used soon after a crime has been witnessed rather than a long time afterwards
− Geiselman (1988)
→ Tested the effectiveness of the cognitive interview by comparing it against SPI techniques
→ Procedure: Showed a video of violent crime to 89 students + about 48 hrs later the students were interviewed using a CI or SPI technique
the students recalled considerably more correct items in the CI than the SPI (41.5 vs 29.4), however the error rates were very similar
− Holliday
→ Showed two groups of children aged 4-5 + 9-10 a 5 min video of a child’s birthday party
→ The next day the children were interviewed about what they had seen using with e standard interview or CI
→ They found the use of CI resulted in more correct details being recalled about the video compared with standard interviewing techniques
Evaluation of the cognitive interview: Research :(
Milne + Bull found that when interviewing using a combination of the report everything + mental reinstatement components recalls were significantly higher than other conditions – this suggests that its only certain aspects of the CI that improve recall rather than the whole thing
Evaluation of the cognitive interview: Practical issues :(
→ Lack of constancy within interview techniques
→ Time consuming
→ Training issues – quality + quantity of training becomes a critical issue
