define encoding
the conversion of information into a form that can be stored by the brain
define capacity
the number of 'chunks' of information a specific memory store can hold at one time.
define duration
the length of time that a specific memory store can hold information without rehearsal
Define rehearsal and state the two types
rehearsal is the repetition of information to ensure it stays present in a memory store.Elaborative and maintenance.
What did Baddely investigate and in what year
The encoding of STM and LTM - 1966
What was Baddely's method
4 groups of participants: semantically similar, semantically dissimilar, acoustically similar and acoustically dissimilar all asked to learn a list of words, they were then asked to recall them after a short time, and then after a long time.
What were Baddely's results and conclusions?
the acoustically similar group did worse at recall after a short time and the semantically similar group did worse at recalling the list after a long period of time. STM encodes acoustically and LTM encodes semantically.
What did Joseph Jacobs investigate and in what year
The capacity of STM (digit span test) - 1887
What was Jacob's method
Participants were given a random list of 20 figures (either letters or numbers). Had to read first figure, look away and say it out loud and then look at the 2nd and say out loud (1st then 2nd etc). Until they couldn't remember and made a mistake
Jacobs' results
average for letters is 7.3 average for numbers is 9.3
Who theorised the multi store model of memory?
Alan Baddely
briefly outline the multistore model of memory
three stores
sensory register
iconic and echoic storage
capacity is massive duration tiny
paying attention to sensory info = transfer into STM
STM
capacity = 7±2 duration about 30 seconds without maintenance rehearsal. Encoded acoustically
maintenance rehearsal keeps info in our STM enough rehearsal transfers to LTM
LTM
capacity is unlimited, coding is semantic, duration is massive
when we want to recall info we have to transfer it back to STM - retrieval
Proactive Interference
When old information makes it difficult to remember new information
Mcgeoch and Mcdonalds aim
To discover if the similarity of memories effects interference
Mcgeoch and Mcdonalds method
Had participants learn a list of 10 words and asked to learn it until they could recall it 100% accurately and then split participants into 6 groups with a new 10-word list, each group had a different condition
Mcgeoch and Mcdonalds results
When participants were asked to recall the original list again, the group they were in for the second list affected their performance
Mcgeoch and Mcdonalds conclusions
Interference is at its worst when memories are similar
Give one weakness of interference theory
Artificial stimuli used in supporting research. This means the research has low ecological validity and is therefore not necessarily applicable to real life
Give two strengths of interference theory.
Research Support: Baddely et.al conducted the rugby study. Players were asked to recall all the teams they had played since the beginning of the season. Players that had taken part in less matches could remember a team they had played for example, 3 weeks ago better than players who had played lots of games since. This is because they had less new information causing proactive interference.
Supporting research- Mcgeoch and Mcdonald
Central Executive
coordinates activity of WMM, processes information and send it to the correct slave system to be processed.
Episodic buffer
a temporary store for info of all kinds
Phonological Loop
Processes auditory information, consists of two parts
Phonological Store
The ‘echo, processes sound
Articulatory Control System
allows for maintenance rehearsal to take place
Visuo-Spatial sketchpad
processes visual information and spatial information when required, can be divided into two parts
Visual Cache
Stores visual data
Inner Scribe
Stores the arrangement of objects in the visual field
Give 2 strengths and a weakness of the working memory model
+: Clinical Evidence - In a case study in which an individual suffered from brain damage, they were not able to process auditory information, but could still process visual information. This proved the separation of the two in the brain.
+: Dual task performance - A study conducted by Baddely himself showed that participants found it harder to perform two visual tasks at the same time than to perform a visual and auditory task at the same time.
-: Lack of clarity over the Central Executive - Some psychologists argue that because Baddely hasn’t given much clarity of how the central executive actually works: it’s difficult to apply it to research and our everyday processing of information.
define interference
forgetting because one memory blocks another, causing one or both to be distorted or forgotten
proposed mainly as an explanation for forgetting in LTM
once info is in LTM it’s more or less permanent - therefore any experienced 'forgetting’ is more likely to be an inability to gain access to the memories, not the loss of them
define proactive interference
forgetting occurs when older memories, already stored, disrupt the recall of new memories - degree of forgetting is greater when the memories are similar
retroactive interference
forgetting occurs when newer memories disrupt the recall of older memories already stored - degree of forgetting is greater when the memories are similar
outline procedure for McGeoch and McDonald’s study (1931)
studied retroactive interference by changing similarity between two sets of materials
participants learnt list oof words until they could recall with 100% accuracy
then they learned a new list - six different groups each learned a different second list
group 1 - synonyms of originals
group 2 - antonyms of originals
group 3 - words unrelated to originals
group 4 - consonant syllables (nonsense)
group 5 - 3 digit numbers
group 6 - no new list; rest condition
then recalled original list
Outline findings for McGeoch and McDonald’s study (1931)
when participants then recalled original words, their performance depended on the nature of the second list
most similar material (synonyms) produced the worst recall
interference is therefore strongest when memories are similar
Give two strengths and a weakness of retrieval failure theory
supporting research uses artificial stimuli - low ecological validity
studies into memory can be over in a sort period of time - whole process of learning and recalling can be over in an hour or so - not representative of real life memory
supported by real life research - Baddely and Hitch found rugby player’s recall of teams they’d played was not so much impacted by time since the match, but by how many teams they had played since.
however, rugby players are susceptible to head injuries and are not a reliable or generalisable sample for normal memory.
Retrieval Failure
an absence of cues
Encoding Specifity Principle
If we use a cue to remember, it must be present at both the time of encoding and the time of retrieval
Context dependent forgetting
Forgetting due to lack of similarity between environment of encoding and environment of retrieval
State dependent forgetting
Forgetting due to a lack of similarity between the physiology of your body at the time of encoding and recall
Godden and Baddelys method and findings
Divers learnt a list of words either on land or underwater and were then asked to recall in either the same condition they learnt it in, or the opposite
accurate recall was 40% lower in non-matching conditions
Carter and Cassadys method and findings
Participants learnt a list of words either on a dose of antihistamine or on no drug at all and then recalled either in same or opposite condition
accurate recall rates significantly lower in non-matching conditions
Give two weaknesses of retrieval failure theory
Context needs to be very different to have an impact on retrieval
logical fallacy, circular reasoning makes it difficult to actually prove or disprove this theory as you can formulate it to cater to any situation.
Give a strength of retrieval failure theory
Supporting evidence - Carter and Cassaday + Godden and Baddely.
Name the three factors affecting eyewitness testimony
Leading questions
Post - event discussion
Anxiety
Leading questions - What was Loftus' aim
Discover effects of leading questions on the accuracy of eyewitness testimony
Leading questions - What was Loftus' method
Participants watched a video of a car crash and were then asked to answer some questions about it. One of these questions was how fast were the cars going when they insert word. Eg: contacted, smashed
Leading questions - What was Loftus' results and conclusions.
Loftus found that the participants who had 'contacted' estimated on average 31.8mph but the participants who had 'smashed' estimated on average 40.5 mph. Leading questions bias the eyewitness recall of an event
define the response bias explanation of leading questions affecting EWT
wording of question has no effect on participant’s actual memory of events - just influences how they choose to answer the question
define the substitution explanation of leading questions affecting EWT
wording of a leading question actually changes the participant’s memory of events
watching video and hearing ‘smashed’ = higher likelihood of reporting seeing broken glass - Loftus
Post event discussion - What was Gabbert's aim?
To discover whether or not post event discussion contaminates an eyewitness testimony
Post event discussion - What was Gabbert's method
Participants were in pairs and watched a video of the same crime but from different points of view. This meant that there were parts of the video that only one of the pair could see, most significantly: a book being held by a young woman. The participant discussed what they had seen with their pair, then completed a test of recall
Post event discussion - What were Gabbert's results
71% of the participants mistakenly recalled items they had not seen in the video (such as the book), these were all picked up in the post event discussion. In the corresponding control group, 0% of participants recounted this.
Post event discussion - What was Gabbert's conclusions
Gabbert concluded that participants often go along with others' views and statements to win social approval - memory conformity
Define memory conformity
The process by which witnesses/ participants often accept others' ideas as true/ go along with them in order to win social approval. OR because they believe or accept that other witnesses are right, and they are wrong
Give a strength of Loftus' leading questions study.
Useful real-life applications: Loftus' studies have had significant effects on the world of eyewitness testimony. Police and courts of law now use this research to gain more accurate eyewitness testimony.
give two weaknesses of misleading information as a factor affecting eye witness testimony
studies use artificial stimuli - participants didn’t actually see the event as an eyewitness would’ve have but watched a video.
individual differences - age: studies typically use younger people but research shows older people have less accuracy
Anastasi and Rhodes (2006) - photo identification of confederate participants was significantly less accurate for older participants.
Anxiety - Negative effects: what was Johnson and Scot's aim
To discover if the physiology created by heightened level of stress that a weapon causes effects accuracy of recall
Anxiety - Negative effects: what was Johnson and Scott's method
Participants were led to believe that they were going to participate in a memory test. They were then led into a room. Loud sounds of fighting were heard from the next room and then a person walked through the room holding either a bloody knife (condition A) or a pen with greasy hands (condition B). Participants were then asked to identify the perpetrator from a selection of images.
Anxiety - Negative effects: what was Johnson and Scott's results and conclusions.
49% of the participants who had seen the perpetrator with the pen could accurately identify them, but only 33% of the participants who had seen the perpetrator with the knife could accurately identify. Johnson and Scott concluded that anxiety has a negative effect on recall
define ‘weapon focus effect’
presence of a weapon narrows a witnesses attention to focus on it because it’s a source of anxiety - ‘tunnel theory’
Anxiety - Positive effects: What was Yuille's aim
To see whether the stress caused by witnessing a crime that causes our fight or flight response to activate makes us more attentive to detail and has a positive effect on recall.
Anxiety - Positive effects: What was Yuille's method
Yuille interviewed witnesses of a real crime: A shooting at a gun shop, 13 of the witnesses were interviewed 5 months after the situation. They were asked to rate the level of stress that they'd felt at the time and then recall the events. The statements were checked for accuracy against the ones given at the time.
Anxiety - positive effects: what was Yuille's results and conclusions.
The participants who reported the highest levels of stress, also gave the most accurate statements. Yuille concluded that anxiety had a positive effect on recall.
Define the Yerkes - Dodson law
The theory that anxiety can have both a positive and negative effect on recall and that the most positive effect is when the intensity of anxiety is medium
Give a weakness of Johnson's weapon focus effect study
The weapon focus effect may not be relevant. the weapon may cause surprise rather than anxiety ( the weapon was not typical of the environment. Pickel did an experiment in a hair salon in which fighting was heard and then someone walked out holding a random object. One of the objects was a pair of scissors (a usable weapon yet typical to the environment) and one was a rubber chicken (not a usable weapon but atypical to the environment of the study). Participants remembered the perpetrator less when they were carrying a rubber chicken, because of the surprise it caused
Field experiments lack control over extraneous variables, less validity as these may have caused the result not the IV.
Ethical issues - Participants were both deceived and in some cases severely distressed.
Give a weakness of the Yerkes Dodson law.
The 'U' explanation may be too simplistic. Anxiety is a complex emotional state and is difficult to measure or quantify. The 'U' theory only acknowledges certain factors affecting it and is overall too reductionist.
Give the 4 main techniques of the cognitive interview
Report everything 2.Reinstate the context 3.Reverse the order 4.Change perspective
Explain technique 1 of the CI
Report Everything - Witnesses are encouraged to report everything that they saw even if they consider it unimportant (this may trigger other important memories)
Explain technique 2 of the CI
Reinstate the context - The witness should return to the original crime scene in their mind and try to recreate the environment eg: how they were feeling, what the weather was like. This may trigger other memories due to the recreation of context cues
Explain technique 3 of the CI
Reverse the order - Events should be recalled in a different order to how they occurred. This is done to prevent participants narrating their expectations of what happened and also to prevent dishonesty
Explain technique 4 of the CI
Change perspective - Witnesses are asked to recall the events of the crime from the perspective of someone else involved. This is done to disrupt schemas of what the witness expects to happen next
What is the enhanced cognitive interview
Extra guidelines for the way that the cognitive interview should be conducted eg: should start with friendly conversation with the witness etc. This is to reduce the effect of anxiety on the witnesses' recall.
Give two weaknesses of the CI
Heavily time consuming
Some elements of the interview may be more valuable than others: Milne and Bull found that 1 and 2 together were more effective than any of the other conditions.
Give two strengths of the CI
Support for the CI's effectiveness: Kohnken et al did a meta analysis and and found that overall, the CI produces more accurate and reliable results
Useful applications in real life police work.