Memory: Key Terms Flashcards
Duration
the length of time information remains in storage within memory (how long a memory lasts)
Sensory Register
a memory store that holds impressions of info received by th five senses
- short duration and a large capacity
Short-term Memory
a temporary memory store for events in the present or immediate past
- short duration + small capacity
Long-term Memory
a more permanent memory store for events that have happened in the more distant past
- long duration and large capacity
Capacity
the amount of info that can be stored in memory at a given time
Coding
The way in which information is changed so that it can be stored in memory
Miller’s Magic Number
- Miller (1956) reviewed research into capacity of STM
- found people can remember about 7 items
- argues capacity of STM is 7, plus or minus 2
- found people can recall 5 words as well as 5 letters - we chunk things together and then can remember more
Ionic Store (Sensory Register)
visual info
Echoic Store (Sensory Register)
auditory info
Haptic Store (Sensory Register)
physical info eg touch
Coded Acoustically (STM and LTM)
coded in terms of how it sounds
Coded Semantically (STM and LTM)
coded in terms of meaning
Coded Visually (STM and LTM)
coded in terms of the image
Duration of SR Research
Sperling (1960):
- showed ps a grid of digits and letters for 50 milliseconds, either asked to write down all 12 or one row
- when asked to recall whole thing it was poorer (42%) than when asked to recall one row (75%)
- the SR has very short duration (0.5 seconds)
- decays rapidly
Duration of STM Research
Peterson + Peterson (1959)
- ps briefly shown consonant trigram, asked to count backwards in threes from specified number, after intervals of 3,6,9,12,15 or 18 asked to recall original trigram
- able to recall 80% of trigrams after 3 seconds, fewer trigrams recalled as time lengthened, after 18 fewer than 10% recalled
- if rehearsal is prevented information vanishes rapidly from STM, very little information can stay in STM for longer than about 18 seconds
Duration of LTM Research
Bahrick et al (1975)
- ex high school students aged 17-74 tested through free recall of names of former classmates, photo recognition of former classmates in set of 50 photos, name recognition, name and photo matching
- 90% accuracy in face and name recognition even when leaving 34 years before, after 48 years declined to 80% for name and 40% for face, free recall considerably less accurate, 60% after 15 years and 30% after 48,
- classmates rarely forgotten once cues been given, recognition better than recall
Capacity of SR Research
Sperling (1960)
- showed ps a grid of digits and letters for 50 milliseconds, either asked to write down all 12 or one row
- when asked to recall whole thing it was poorer (42%) than when asked to recall one row (75%)
- large capacity
- ps didn’t know which row they would be asked to recall but still managed to recall so it’s assumed that all was held in the sensory register but it decayed rapidly,
Capacity of STM Research
Jacobs (1887)
- ps presented with string of letters or digits and had to repeat them back in the same order, number of digits or letters increased until ps failed to recall correctly
- recalled about 9 digits and 7 letters, STM has limited capacity of 5-9 items
Miller (1956)
- reviewed research into capacity of STM
- found people remember about 7 items, argues capacity of STM is 7 plus or minus 2, found people can recall 5 words as well as 5 letters - we chunk things together and then can remember more
Capacity of LTM Research
Linton (1975)
- large capacity
- autobiographical study with memory diary to record 6 years of events, randomly select pairs of records once a month and try to estimate chronological order and date
- memory for real life events decreased at rate of 5%, finally year of study 30% events recorded forgotten
Coding of SR Research
Crowder (2003)
- different depending on store
- few milliseconds in ionic
- 2-3 seconds in echoic
Coding of STM Research
Baddeley (1966)
- 4 groups presented with list of words repeated 4 times, A: acoustically similar, B: acoustically dissimilar, C: semantically similar, D: semantically dissimilar, given list in wrong order and had to rearrange without 20 minute interval
- acoustically similar performed worst (10%) other lists 60-80%
- STM coded acoustically
Coding in LTM Research
Baddeley (1966)
- 4 groups presented with list of words repeated 4 times, A: acoustically similar, B: acoustically dissimilar, C: semantically similar, D: semantically dissimilar, given list in wrong order and had to rearrange with 20 minute interval
- semantically similar performed worst (55%) other lists 70-85%
- LTM coded semantically
Multi-Store Memory Model
- Atkinson and Shiffrin (1968)
- theoretical model that explains how info flows from one storage system to another
- unitary: different units to it
- structural: areas arranged in a certain way
- linear: in a line, flowing in one way
Process of Multi-Store Memory Model
1) the sensory store is constantly receiving info from our environment
2) if you pay attention to it data is transferred to STM if not it will disappear (decay)
3) rehearsal maintains info in STM
4) info will disappear if it isn’t rehearsed or if new info enters the STM pushing out (displacing) original info
5) the more something is rehearsed by rote repetition the more lasting the memory will be
6) loss of info from LTM is due to decay, interference or problems in retrieval
2 types of LTM
Implicit: actions/behaviours, no experience of recall, no conscious attention
Explicit: events or facts, recall, conscious attention
Type of Implicit Memory
procedural: memory for how to do things, automatic and result of repeated practice
2 Types of Explicit Memory
Semantic: memories about the world that are shared by everyone in terms of facts and knowledge
Episodic: personal memories of events, includes contextual details and an emotional tone
Central Executive
- monitors and coordinates all other mental functions in working memory
- directs attention to particular tasks and has limited capacity
Visuo-Spatial Sketchpad
codes visual info in terms of separate objects as well as the arrangement of those objects in visual field
2 Stores in Visuo-Spatial Sketchpad
visual cache: stores info about visual items
inner scribe: stores arrangement of objects
Episodic Buffer
receives input from many sources, temporarily stores this info then integrates it in order to construct a mental episode of what is being experienced
Phonological Loop
- codes speech sounds in working memory typically involving maintenance rehearsal
- limited capacity
2 Stores in Phonological Loop
phonological store: holds words you hear
articulatory process: holds words that are heard or seen
Interference
- an explanation for forgetting in terms of one memory disrupting the ability to recall another
- most likely to occur when two memories have some similarity
- occurs from LTM as we can’t access memories even though they are available
2 Types of Interference
pro-active: when past learning (old memories) interfere with current attempts to learn (new information), because previously stored info makes new info difficult to store
retro-active: when current attempts to learn (new information) interferes with past learning (old memories), because new info overwrites previous memories that are similar
Retrieval Failure
- occurs due to absence of cues
- an explanation for forgetting based on the idea that the issue relates to being able to retrieve a memory that is there but not accessible
- retrieval depends on using cues
Retrieval Cues and 2 Types
- serve as a reminder
- context dependent: environmental factors
- state dependent: persons mental state
Endel Tulving (1973)
- “memory is effective if info that was present at encoding (when we learn material) is also available at time of retrieval”
- “if cues that are available at retrieval and encoding are different then there will be some forgetting”
- cues don’t have to be exactly the same but closer to original more useful
Eye Witness Testimony
a legal term referring to the use of eye witnesses (or ear witnesses) to give evidence in court concerning the identity of someone who has committed a crime
Misleading Information and 2 Types
- EWT is affected by experiences which occur after witnesses observe the critical event
- leading qs: qs that either by their form or content influence a person’s schemes in order for them to give a desired answer
- post-event discussion: a conversation between cowitnesses after a crime takes place in which critical info is discussed and leads to contaminated memory
Leading Questions: Loftus
- week later: ps questioned again about accident with new critical q: did you see any broken glass?
- ps who had been asked the ‘smashed’ version of question more likely to report having seen broken glass at scene even though there was none
Post Event Discussion
- when cowitnesses to a crime discuss event with each other their EWT could become contaminated
- individuals remember misinformation from others and combine that with their own memory
- also known as conformity effect
The Weapon-Focus Effect
in violent crimes, arousal may focus the witness on more central details of the attack than the more peripheral details, sometimes called “Tunnel Theory”
Yerkes-Dodson Law
- states that memory improves with increases in arousal up to an optimal point and then declines with further increases
- this means that small to medium increases in arousal may increases the accuracy of memory, but high levels interfere with accuracy
4 Steps of Cognitive Interview
1) report everything
2) mental reinstatement of original context
3) changing the order
4) changing the perspective
Cognitive Interview: Report Everything
- interviewer encourages the reporting of every single detail of the event even though some of it may seen insignificant or irrelevant
- this is because trivial details may be important and may act as a cue and trigger other important memories
- stops witnesses, victims and suspects withholding information
- gets the maximum quantitiy of detail
Cognitive Interview: Mental Reinstatement of Originial Context
- interviewer encourages the interviewee to mentally recreate the environmental (place, weather) and emotional content (feelings) of the crime scene
- aim is to make memories accessible by using appropriate cues to retrieve memories
- gets people to slow down and think about the scene and create a picture in their head
Cognitive Interview: Changing the Order
- the interviewer may try alternative ways through the timeline of the interval eg reversing the order in which events happened
- the rationale behind this is that our recollections are influenced by schemas. by recalling events in different order, it prevents pre-existing schemas from influencing what you recall.
- can detect deceit
- remember what happened on specific day instead of normal routine
Cognitive Interview: Changing the Perspective
- interviewee is asked to recall the incident from multiple perspectives eg by imagining how it would have appeared to other witnesses present at the time
- again this is also done to disrupt the effect that schemas have on recall
- think about the bigger picture instead of just them and role of other people
Enhanced Cognitive Interview
- Fisher (1987) developed some additional elements of the cognitive interview to focus on the social dynamics of the interaction
- for example, the interviewer should know when to establish and relinquish eye contact
- the enhanced CI also includes techniques to reduce eye witness anxiety, minimise distractions, getting the witness to speak slowly and asking open-ended questions
Key Study: Loftus and Palmer (1974)
Aim: to investigate the accuracy of memory in EWT
Procedure: 45 students shown 7 different accidents, given questionnaire with one critical q: ‘about how fast were the cars going when they hit each other’, one group given this q, other 4 groups had verbs smashed, collided, bumped or contacted instead of hit
Findings: group with ‘smashed’ estimated higher speed (41mph), group with ‘contacted’ estimated lowest (30mph)
Conclusion: EWT is generally innacurate and unreliable, form of qs can have a significant effect on answers
Key Study: Johnson + Scott (1976)
Aim: to investigate the weapon-focus effect and its impact on accuracy of recall
Procedure: ps asked to sit in waiting room and heard discussion in nearby room, condition 1: man came out with pen and grease on hands, condition 2: man came out with knife covered in blood, asked to identify man from 50 photos
Findings: condition 1: 49% accurate, condition 2: 33% accurate
Conclusion: presence of weapon causes attention to be drawn towards weapon, anxiety has negative effect on EWT
Key Study: Christianson + Hubinette (1993)
Aim: to investigate the positive effect of anxiety on EWT
Procedure: questioned 58 witnesses to real bank robberies in Sweden, witnesses either bank tellers (victims, high anxiety) or bystanders (employees and customers, low anxiety), conducted interviews 4-15 months after
Findings: all witnesses showed good memories for details (better than 75% accuracy), those who were most anxious had best recall
Conclusion: anxiety has positive effect on EWT
Key Study: Gabbert et al (2003)
Procedure: each participant watched video of same crime from different angle, pairs in condition 1 sicussed event before recall, pairs in condition 2 didn’t
Findings: 71% in condition 1 mistakenly recalled aspects of the video they hadn’t seen themselves, 0% in condition 2
Conclusion: witnesses go along with each other, wither to win social approval or because they believe that the other witnesses are right and they are wrong they called this memoty conformity
