all Flashcards
define capacity
The amount of information that can be held in a memory store
define duration
How long information can be stored for
define encoding
in what form information can be stored
What was the method of Baddeley (1996) and his research into short term memory?
75 ppts divided into 4 groups and each shown 1/4 word lists:
- acoustically similar
- acoustically dissimilar
- semantically similar words
- semantically dissimilar words
Ppts were asked to recall the words in the correct order
What were the results of Baddelely (1996) and his research into short term memory?
- Acoustically similar = 10% recall
- Acousticaly dissimilar = 80% recall
- Semantically similar words = 60% recall
- Semantically dissimilar words = 70% recall
What was the conclusion of Baddelely (1996) and his research into short term memory?
The acoustically similar words of list A interfere with the STM and its ability to code the words. Because the words sounded the same, the STM was unable to differentiate between them.
This was the same for list C and the semantically similar words.
What did Miller (1956) research into short term memory show?
showed that people have a STM capacity of 7 chunks (+ or - 2) –> this is know as millers magic 7.
What was the procedure of Peterson and Peterson’s (1959) study into short term memory?
- ppts were briefly shown a consonant trigram
- ppts were asked to count backwards in 3s to stop them releasing trigrams
- after intervals of 3, 6, 9, 12, 18 secs ppts were asked to recall original trigram
- procedure repeated with different trigrams
What were the results of Peterson and Peterson’s (1959) study into short term memory?
- Ppts recalled approx. 80% of trigrams after 3 secs.
- As interval increased fewer trigrams were remembered.
- After 18 secs, less then 10% of trigrams were recalled correctly.
What was the procedure of Barrack et al’s (1975) study into long term memory?
- research into graduates from high school over a 50yr period - they were shown photos of their high school year group
- the RECOGNITION group were given names and asked to match the name to the person
- the RECALL group were asked simply to name them
What were the results of Barrack et al’s (1975) study into long term memory?
Those who left high-school in the last 15 years: 90%
Those who left high-school in the last 48 years: 80%
What are strengths of research into STM?
1). Supporting Evidence = all done in a lab so there is a high control of EVs so easily establish cause and effect relationship
2). The use of trigrams in Peterson and Peterson study ensured no meaning was attached which could have acted as a confounding variable
What are the weaknesses of research into STM?
1). artificial stimuli in supporting evidence studies –> the lack of meaning behind them lowers generalisability and external validity
2) Baddeley = not measuring capacity but actually how much someone can say in 2 secs
3) Peterson and Peterson = could have been the trigrams were displaced by the number used to stop rehearsal not because of weak memory trace.
What is the function of the sensory store in the Multi-Store Model?
to help integration between all the senses as we receive information from them.
What is the capacity of the sensory store?
unlimited
What is the duration of the sensory store?
Less than half a second
How is information encoded in the sensory store?
all senses
How is information transferred from the sensory store to the short term memory?
if attention is given to the information
If the information in the sensory store is not transferred to the short term memory store, what happens to it?
Trace Decay - it is forgotten
How does information stay in the STM store?
Maintenance rehearsal
In the STM store, if we don’t rehearse the information, what happens to it?
it is forgotten
What is the capacity of the STM store?
7 chunks of info ( + or - 2)
What is the duration of the STM store?
18-30 seconds
How is information encoded into the STM store?
acoustically
How is information transferred from the STM to the LTM?
prolonged rehearsal
What happens when we retrieve information from the LTM store?
the information is brought back into our STM.
What is the capacity of the LTM store?
unlimited
What is the duration of the LTM store?
a lifetime
How is information encoded into the LTM store?
semantically
What are the strengths of the multi-store model of memory?
1) Clive Wearing Case Study = he had an STM of 7 secs and can’t lay down new LTM, but can still play piano (procedural LTM not semantic) = suggest separate stores for STM and LTM
2) Supporting evidence from Murdocks Serial Position Curve –> the primary and recency effect suggest MSM exists
3) Supporting evidence from Baddeley (1996)
What are the weaknesses of the multi-store model of memory?
1) The model appears too simple to explain the entirety of human memory as each store is very complex to be approached by a single idea.
2) Case Study from Clive Wearing shows evidence of separate LTM stores –> MSM doesn’t explain this
3) May not be valid theory in real life - studies have only shown the effects of MSM using constant trigrams / numbers with no meaning, whereas in real life we have to remember a lot more e.g. faces, names and facts
What are the 3 types of long term memory?
episodic, semantic, procedural
Define episodic memory
memory of one’s personal past experiences
(usually time stamped and require conscious effort to recall)
Define semantic memory
facts and general knowledge
(easy to recall and constantly being updated)
Define procedural memory
memory for how to carry out skilled movement / how to do things
What are the strengths of different LTM stores?
1) Case study of Clive Wearing - had procedural memories not episodic - illustrates separate stores of LTM
2) Tulving Gold Memory Study –> injected radioactive gold and PET scans completed to measure blood flow when ppts were asked about different LTMS - 50% showed a difference in blood flow with different types of LTMs = objective + replicable
3) Real life application = Belleville (2006) used the theory to improve episodic memory recline the the elderly who had mild cognitive impairment = generalisable and external validity
What are the weakness of different LTM stores?
the fact its based upon case studies is problematic as case studies are on singular people and the same conditions could affect people differently thus they can’t be generalised and classed as representative.
What is the function of the central executive in the working memory model?
- controls our attention
- decides what happens to incoming info and what slave system to allocate it to
- limited capacity and can only pay attention to one thing at a time
- codes through all senses
What is the function of the phonological loop in the working memory model?
- deals with incoming auditory information
- is split into 2 parts; articulatory control store and phonological store
What is the function of the articulatory control store (within the phonological loop) in the working memory model?
- rehearses information verbally
- articulatory suppression can be used to prevent this
What is the function of the phonological store (within the phonological loop) in the working memory model?
encodes acoustically but the information will deal if not rehearsed by the ACS
- the link between incoming info and our LTM
- processes info
- capacity of what you can say in 2 secs
What is the function of the visuo-spatial sketchpad in the working memory model?
- stores and manipulates visual info from either the eyes of LTM
- Works separately to the phonological loop
- separated into 2 stores: visual cache and inner scribe
What is the function of the visual cache (within the visuo-stpaial sketchpad) in the working memory model?
stores visual data
What is the function of the inner scribe (within the visuo-stpaial sketchpad) in the working memory model?
records the arrangement of objects in the visual field (linked to perception)
What is the function of the episodic buffer in the working memory model?
- binds together all the other components of the working memory
-records info in order and time - prepares memories for stager in our episodic LTM
- uses previous memories from LTM to be integrated into a novel situation
- limited capacity = 4 chunks of info
Supporting evidence for the Central Executive….
- ppts split into 2 groups; ppts who did 2 tasks and ppt who did 1
- fMRI was used to see which parts of the brain where active during these tasks
- same part of the brain (pre-frontal cortex) showed activity during the two conditions but showed increased activity in the ‘2 task’ condition.
- shows that there is an area of the brain specific to attention
Supporting evidence for the Phonological Loop….
- Baddeley found that ppts memory span for visually presented 1 syllable word was greater than polysyllabic words.
- suggests that articulatory loop is limited to a number of syllable chunks
- when repeated using an articulatory suppression task, the word length effect disappeared –> suggests the articulatory loop was taken up during suppression task.
Real life application for the Phonological loop…
Case study of KF forgot more auditory info than visual info = suggest the phonological loop and visuo-spatial sketchpad are different stores.
Supporting evidence for the Visuo-spatial sketchpad…
- ppts were given 2 visual tasks; one was to track a light with a pointer at the same time as imagining and describing the letter ‘F’ and the other tracked the light whist doing a verbal task.
- they found the tracking easy with the verbal task
- suggests that the tracking and describing the letter ‘F’ were competing for the limited recourses of the sketchpad
Supporting evidence for the episodic buffer…
- Baddeley = ppts were shown words and then immediately asked to recall them.
- recall was better for sentences (related words) then unrelated words.
- supports the idea of a general memory store that draws on the LTM
What are evaluations for the Working Memory Model itself?
+ explains limitations of the MSM –> explains why we remember something we didn’t rehearse - episodic buffer processes and brings all the elements together
+ high in face validity –> meaning the model seem plausible because it fits in with everyday experiences of manipulating info when solving problems, with the STM being a dynamic process rather that a static state
- functions of the central executive are vague and difficult to test –> difficult in practice to determine which processes are part of the central executive or other slave systems
Define cue
A trigger of information that allows us to access a memory
Define retrieval failure
Forgetting occurs when we don’t have the necessary cues to access memory and retrieve info
What does the encoding specificity principle state?
Tulving’s research found that if a cue is to help with recalling information, it needs to be present at encoding and at retrieval. If the cues are different at encoding and retrieval forgetting occurs.
What is context-dependent forgetting?
this suggest that WHERE we learn material and WHERE we remember material serve as EXTERNAL CUES and affect our retrieval.
Supporting evidence of context-dependent forgetting….
GODDEN AND BADDELEY - used deep sea divers and asked them to learn a list of words in one place and recall them in another. The conditions where:
- learn on land, recall on land
- learn on land, recall underwater
- learn underwater, recall underwater
- learn underwater, recall on land
FINDINGS = accuracy on recall was 40% lower in the 2 non-matching conditions. Suggested that this was because the cues at encoding were not present at recall = retrieval failure
What is state-dependent forgetting?
this suggests that if the internal mood or state is different to the one we are in at the time of recall, then this will affect retrieval and we are more likely to forget.
Supporting evidence for state-dependent forgetting?
CARTER AND CASSIDY -ppts given anti-histamines to induce drowsiness (a different state than normal). Ppts had to learn a list of words and recall them. The conditions were:
- learn on drug, recall on drug
- learn on drug, recall without drug,
- learn without drug, recall without drug
- learn without drug, recall on drug
Recall was less accurate for non-matching conditions as internal state was different at encoding and retrieval
Retrieval Failure Theory ….
… the reason why we forget is due to insufficient cues.
- when we encode a new memory we also store information that occurred around it (cues).
- if we can’t remember or recall the information, it could be because we are not in a similar situation to when the memory was originally stored
- if the cues are not present when we come to recall them we find it difficult to retrieve the memory.
- it is not necessarily because we have forgotten it, its just that we don’t have the cues to help us access the memory
- the memory is still available - it is just a problem with accessing the memory
Strengths of Retrieval Failure Explanations
- Supporting evidence from Godden and Baddeley deep sea divers and Carter and Cassidy antihistamine experiment.
- Practical Applications - cue dependent theory could help eye witnesses recall events - used in Cognitive Interviews - witnesses encouraged to remember details through the use of external cues
Weaknesses of Retrieval Failure Explanations
- not complete explanation - the explanation doesn’t explain what happens if we still forget even if the cues are present at encoding and retrieval - doesn’t take into account other reasons e.g. interference
- No large effect - Baddeley did suggest that the effect of context on forgetting it not very strong –> whilst the difference between land and sea is a big one, Mose daily environments are quite similar. - in real-life context dependent forgetting doesn’t completely explain why we forget.
Interference theory
- forgetting because one memory blocks another, causing one or both memories to be distorted or forgotten
- interference between memories makes it harder for us to locate them in the LTM and is experienced as forgetting
Proactive Interference
Forgetting that occurs when old memories disrupts the recall of new memories
retroactive interference
forgetting that occurs when new memories disrupts the recall of old memories
What were McGeoch and McDonald’s (1931) research into the interference theory measuring?
the effect of similarity between memories
What was the method of McGeoch and McDonald’s (1931) experiment into the interference theory?
- studied retroactive interference by changing the amount of similarity between two sets of materials
- ppts had to learn a list of 10 words until they had 100% recall accuracy
- they then learnt a new list
- 6 groups of ppts with different 2nd lists (synonyms / antonyms / unrelated words to the original / numbers/ 3 digit number / no new list - ppts retested
- ppts were then asked to recall original list
What were the results of McGeoch and McDonald’s (1931) experiment into the interference theory?
- the performance depended on the nature of the 2nd list
- the most similar material (synonyms) produced the worst recall.
- interference is strongest when memories are similar
Strengths of the interference theory.
- Supporting evidence from McGeoch and McDonald
- Supporting evidence from Baddeley and Hitch - found interference effects with rugby teams remembering the name of teams they had played over the season. - those who played more forgot more = more interference
- Assistance through cues - Tulving and Polska = ppts given 1st list of words recall = 70% / then given 2nd list, recall of 1st list = lower / after given cues, 1st list = 70% again –> shows that interference effects can be minimised if connection are made at the coding stage.
Weaknesses of the interference theory
- artificial materials - this experiment use list of unconnected words = unlike tthingswe have to remember in the real world and therefore lowers the generalisability of the studies
- artificial situations - ppts asked to learn and repeat lists of words within short time periods - whilst this does maximise the chances of interference occurring, doesn’t happen in real life = limits generalisability
Eyewitnesses
they are people who are knowingly or unknowingly have seen a crime or whose information can help police apprehend those criminals involved in the crime
During eyewitness testimonies, what are thought to be the 3 stages where sources of error occur?
- Acquisition
- Storage
- Retrieval
Who was the key researcher of experiment on Misleading questions?
Elizabeth Loftus
What was the aim of Loftus and Palmer’s ‘reconstruction of an automobile’ experiment?
To investigate how leading questions asked of a witness after an event will influence their memory of that even.
What was the method of experiment 1 in Loftus and Palmer’s ‘reconstruction of an automobile’ experiment?
- 45 student participants were shown short video clips
- They were split into 5 groups, with 9 participants in each one.
- All of the participants were asked: ‘About how fast were the cars going when they ________ each other’
- Each group was given a different verb to fill in the blank. which were either ‘smashed, collided, bumped, hit or contacted’.
- The ppts estimated speed was then recorded
What was the results of experiment 1 in Loftus and Palmer’s ‘reconstruction of an automobile’ experiment?
- How the question was phrased influenced the participants’ speed estimates
- When the verb ‘smashed’ was used, participants estimated that the cars were travelling much faster than when the verb ‘contacted’ was used.
What was the conclusion of experiment 1 in Loftus and Palmer’s ‘reconstruction of an automobile’ experiment?
- Loftus concluded that the leading question used actually changed the memory that they ppt had of the film.
- She called this the substitution explanation. - ie the ppts substituted their memory with a new one because of the leading question.
- She supported this view with the following experiment.
What was the method of experiment 2 in Loftus and Palmer’s ‘reconstruction of an automobile’ experiment?
- 150 student participants were shown a short film that showed a multi-vehicle car accident and then they were asked questions about it.
- The participants were split into 3 groups (with 50 in each group).
- One group was asked:-
‘How fast were the cars going when they hit each other?’ - The second was asked:
‘How fast were the cars going when they smashed into each other?’ - The third group was not asked about the speed of the vehicles
- One week later, all participants returned and were asked:
‘Did you see any broken glass?’ - There was no broken glass in the film.
What was the results of experiment 2 in Loftus and Palmer’s ‘reconstruction of an automobile’ experiment?
- The results show that the verb used in the original question influenced whether the participants thought they had seen broken glass.
- ‘smashed’ condition = more said they saw broken glass then ‘hit’ condition and the control
What was the conclusion of experiment 2 in Loftus and Palmer’s ‘reconstruction of an automobile’ experiment?
Loftus and Palmer suggest that 2 kinds of information go into a person’s memory for an event:
-Firstly, the person’s own perception of the event (at the time), - Secondly, information supplied after the event (such as leading questions).
Post-event discussion theory
- occurs when there is more than one witness to an event.
- Witnesses may discuss what they have seen with co-witnesses or with other people.
- This then alters their own memories and they claim to remember to have seen things they haven’t.
Supporting evidence for the Post-event discussion theory.
FIONA GABBERT ET AL:
- Studied participants in pairs.
- Each watched a video of the same crime, but filmed from different points of views.
- In the experimental condition the ppts then discussed what they saw and then asked about what they remembered.
- FINDINGS = 71% recalled aspects that they did not see in the video in experimental condition but in the control group 0% of inaccurate info recalled.
- She concluded witnesses go along with each other, to win social approval or because they believe the other witnesses are right.
strengths of misleading information affecting EWT
- supporting evidence from Loftus —> ppts shown a video of car accident with stop sign - 1/2 ppts asked misleading questions and 1/2 ppts asked normal question - misleading questions remembered stop sign as yield sign
- practical applications - the importance of research into EWT - direct impact on what police interview witnesses and development of CI - potential to reduce chances of wrong convictions
weaknesses of misleading information affecting EWT
- refuting evidence from guile and catchall gun robbery case study
- methodology issues - argued that ppts in Loftus study showed demand characteristics - ppts with to please and appear more helpful
- tasks are artificial - watching clips of car accidents = very different from real life - studies with artificial task show little about leading questions and EWT in reality - lowers external validity
- other explanations - response bias - the wording of the question has no real effect on ppts memories - does just affect their answer/how they respond - memories are not substituted only their answers are.
Weapon focus effect
if a weapon in a crime situation, anxiety levels increase, memory is reduced so we stop paying attention to important details
Tunnel theory of memory
Argues that a witness’s attention narrows to focus on a weapon, because it is a source on anxiety. We are less likely to remember peripheral details
What was the aim of Johnson and Scott’s (1976) experiment on the effect of anxiety on recall?
To see if anxiety affects accuracy of later id.
What was the method of Johnson and Scott’s (1976) experiment on the effect of anxiety on recall?
- While seated in a waiting room thinking they were taking part in lab experiment ppts overhead a heated conversation in the next room
- In the low anxiety condition a man walked through holding a pen with grease on his hands
.- In the high anxiety condition they also heard sounds of breaking glass and crashing chairs, a man emerged and crossed through the waiting room with paper-knife covered in blood. - PPts given 50 photos an asked to identify the man that they saw
What were the results of Johnson and Scott’s (1976) experiment on the effect of anxiety on recall?
- Pen condition: Accurate id 49% of the time
- Blood stained knife condition: Accurate id 33% of the time
- TUNNEL THEORY OF MEMORY = witness concentrates on weapon, distracting attention.
- Fear induced by the weapon narrows focus so giving rise to less accurate details of peripheral details.
What was the aim of Yuille and Cutshall’s (1986) study into anxiety affecting EWT?
- Record and evaluate accuracy of witness accounts and errors made
- Examine issues raised by lab research
What was the method of Yuille and Cutshall’s (1986) study into anxiety affecting EWT?
- conducted a study of an actual shooting in a gun shop
- the owner show the thief
dead - there were 21 witness of which 13 took part in the study
- they were interviewed 4-5 months after the incident and these interviews were compared with the original police interviews at the time of the shooting
- accuracy was determined by the no. of details reported in each account
- were also asked to rank their stress levels and whether they had any emotional problems since the event
What were the finding and conclusion of Yuille and Cutshall’s (1986) study into anxiety affecting EWT?
- the witnesses were very accurate in their accounts and there was little change in amount recalled or accuracy after 5 months
- the ppts who reported highest levels of stress were more accurate (88% compare to 75% of less stressed group)
- suggest that anxiety doesn’t have a detrimental effect on accuracy of EWT in real-world context and may even enhance it
What does the Yerkes-Dodson law state?
Arousal can increase performance, but only to a certain point. At the point arousal becomes excessive, performance decreases.
weaknesses of anxiety affecting EWT.
- weapons may test surprise rather than anxiety - eyewitness accuracy was significantly poorer in unusualness conditions (the chicken and handgun) than in (wallet & scissors). = weapon focus effect is due to to unusualness not anxiety
- too simplistic = measuring anxiety accurately and objectively is difficult + yerkes and Dodson curve only takes into account physical arousal –> needs to take into account emotional factors
- ethical issues - ppts in lab experiments are subjected to an amount go psychological harm. In field studies, ppts have ‘naturally’ been through anxiety including situations so more beneficial despite issues of control
- little control in field studies (e.g. Yuille and Cutshall) - little control over what happens between the event and when they do the study - post event discussion could have occurred
what are the 4 factors included into cognitive interviews, and why?
- REPORT EVERYTHING - may trigger other important memories (cues)
- RECREATE ORIGINAL CONTEXT - use of context and state dependent triggers
- CHANGE THE ORDER - prevents expectation and prevents chemise reconstructing memories
- CHANGE THE PERSPECTIVE
what are the features of enhance cognitive interviews?
Fischer added elements to the CI to focus on social interactions between the interviewer and the witness.
focused on eye-contact, reducing witness anxiety, minimising distractions and asking open-ended questions
strengths of cognitive interviews
- fisher et al assessed detective in Florida before and after training in CI techniques - found that information gain was as much as 41% using CI techniques
- Beckalian and Bennet –> meta-analysis of 27 studies found improvement in all suggesting worthwhile tool to improve eyewitness accuracy
weaknesses of cognitive interviews
- refuting evidence - Kohnken et al showed an 81% increase in accuracy of EWT using CI but also a 61% increase in inaccurate info recalled - undermines effectiveness of CI as it may be difficult to tell the difference between accurate/inaccurate info
- success may be due to experienced detectives. - merman et al found that experienced detectives improved recall of interviewees then those who had 4 hrs of training - has huge implications for CI as training is expensive and time consuming.
