Memory Flashcards
Coding
- The format in which information is stored in the various memory stores
Capacity
- The amount of information that can be held in a memory store
Duration
- The length of time information can be held in memory
Short-term memory (summary)
- limited capacity memory store
- capacity: 5-9 items
- coding mainly acoustic (sounds)
- duration: 18-30 seconds
- unless rehearsed then can pass into LTM
Long-term memory (summary)
- permanent memory store
- coding mainly semantic (meaning)
- capacity: unlimited
- duration: up to a lifetime
Baddeley coding research: method
- memory is stored in different formats, depending on the memory store
- process of converting information from one form to another = coding
method:
- gave different lists of words to four groups of p’s to remember:
1. acoustically (sounding) similar: e.g. cat, cab, can
2. acoustically dissimilar: e.g. pit, few, cow
3. semantically similar (meaning) e.g great, large, big
4. semantically dissimilar: e.g. good, huge, hot - P’s were then shown a list of these words and asked to arrange them into the correct order
Baddeley coding research: findings
- when the recall task was given immediately after hearing it (short-term memory recall) they did worse with ACOUSTICALLY similar words
- –> suggests STM codes acoustically
- when the recall task was given after a time interval of 20 minutes (long-term memory recall) they did worse with the SEMATICALLY similar words
- –> suggests STM codes sematically
Jacobs capacity research: method
- used digit span to measure capacity
- 4 digits given to P and then P asked to recall them in the correct order out loud
- if they get this correct this researcher then gives 5 digits (+1)
- and so on until the P is unable to recall the order correctly- this determines the induviduals digit span
Jacobs capacity research: findings
- mean average digit spans:
digits = 9.3
letters = 7.3
Research on duration of STM: method
- 8 trials, 24 students
- in each trial student is given a triagram e.g. LDY. KJC, LPS, etc. and a 3 digit number e.g 634. 392, 912
- then asked to count backwards from that number to prevent any rehearsal of the trigram which would increase the memory
- in each trial they were asked to stop after a different amount of time- 3,6,9,12,15 or 18 seconds
- the retention interval
- the number of correct responses decreased at retention interval time increased
Research on duration of STM: findings
- STM has a short duration unless we are able to repeat it out loud over and over again (maintenance rehearsal)
Miller capacity research
- observation of everyday practice
- noted that many things come in sevens e.g. days of the week, deadly sins, etc.
- suggested the span or capacity of the STM is about 7 items plus or minus 2
- also noted that [people can recall 5 words just as well as they can recall 5 letters –> they do this by grouping set into units or chunks –> chunking
Research on duration of LTM: method
- 392 P’s between 17-74
- obtained high school yearbooks of each
- tested recall in various ways:
1. photo recognition test (names from pictures)
2. free recall: recalled all names of graduating class
Research on duration of LTM: findings
- P’s tested within 15 years of graduation were 90% accurate in phot0 recognition
- after 48 years recalled declines to 70%
- free recall was worse: 15 years = 60% 48 years = 30%
- LTM can last a long time
Evaluation: Baddeley
P - artificial stimuli
E - the random list of words were quite artificial rather than meaningful or personal to the participants
C - we should be cautious about generalising the findings to different types of memory tasks
- e.g. processing more meaningful info –> here people may code semantically even in short term memory tasks
–> limited application
Evaluation: research on capacity
P - Jacobs digit span test lacks validity
E - It was conducted a long time ago when psychological studies often lacked adequate control
e.g. some P’s may have been distracted when being tested so didn’t preform as well
- results may not be valid due to confounding variables that were not controlled
H - the results have been replicated in newer research supporting its validity
P - use Miller to support Jacobs and vise a versa
P - Miller did not specify how large each ‘chunk’ of information could be
E - therefore we are unable to conclude the exact capacity of short-term memory.
C - further research is required to determine the each size of information ‘chunks’ to understand the exact capacity of short-term memory.
P - Miller’s (1956) research into short-term memory did not take into account other factors that affect capacity.
E - e.g. age could also affect short-term memory
C - Jacobs (1887) research acknowledged that short-term memory gradually improved with age.
Name all features in order of the multi-store model of memory
- -> stimulus from the environment
- -> Sensory register - iconic, echoic, other sensory stores
- -> short term memory store
- -> long term memory store
- response (memory)
- maintenance rehearsal (rehearsal loop)
- retrieval
- prolonged rehearsal
Sensory register
- stimulus from the environment will pass into the sensory register
- sights, sounds, smells, etc
- this part of the memory is not one store but many (one for each of the 5 senses)
- 2 main:
- -> echoic (coded: acoustically) - duration: 3 secs
- -> iconic (coded: visually) - duration: less than half a second
- capacity: high - 100 million cells in one eye
- info only passes further into the memory system if it is paid ATTENTION to
Maintenance Rehearsal
- when we repeat material to ourselves over and over
- can keep info in our STM as long as we rehearse it
- if we rehearse for long enough the info will pas into the LTM
The multi-store model of memory
- representation of how memory works in terms of 3 stores
- sensory register, the short term memory and the long term memory
- describes how info is transferred from one store to another, how it remembered and how it is forgotten
The multi-store model of memory: evaluation
P - case study evidence support
E - The case of HM supports the MSM
- he was unable to encode new long-term memories after surgery where his hippocampus was removed but his STM was unaffected.
- He remembered little of personal (death of mother and father) events that had occurred over the last 45 years.
C -This supports the view that the LTM and the STM are two separate stores.
H - however it could be said his case does not offer good support for the msm since it is a case study and a unique case of a brain damaged individual so it may not generalise to all memory
P - There is more than one type of short term memory
E - MSM says it is a unitary store
- evidence from people with amnesia shows this cannot be the case
- case study: KF
- short term memory for digits was poor when read out to him
- but recall was much better when he read them to himself
C - this research shows that the very least there must be one short-term store to process visual info and one for audial info
P - A lot of the research used to define the coding, capacity and duration of the stores was artificial
E - in every day life memories are more related to meaningful and useful things
- e.g. facts, names, places, etc
- the studies used meaningless subjects such as in P&P’s trigrams that have no real meaning for the P
C - lacks ecological validity and may not reflect how memory woks in every day
The working memory model
- a representation of short term memory i organised and how it functions
- it suggests that STM processes different types of information using sub-units coordinated by a central decision-making system
- each component is qualitavely different based off of coding and capacity
Central Executive
- monitors incoming data, makes decisions and co-ordinates the activities of the three sub-systems in the memory
- very limited processing capacity
Phonological loop
- one of the slaves systems
- deals with auditory info (coding is acoustic)
- preserves the order in which info arrives
- divided into:
- phonological store: stores the words we hear
- articulatory process: allows maintenance rehearsal (repeating sounds or words in a ‘loop’ to keep them in working memory while they are needed) capacity of this loop = 2 secs worth of what you can say
Visuo-spatial sketchpad
- one of the slave systems
- stores visual/spatial information when required
- sub-divided into:
- visual cashe: stores visual data
- inner scribe: records the arrangement of objects
in the visual field - temporary - limited capacity 3-4 objects
Episodic buffer
- one of the slave systems
- a temporary storage for information.
- integrates visual, spatial and verbal information.
The Working Memory Model: Evaluation
P - support for multiple STM memory stores
E - evidence from people with amnesia supports this
- case study: KF
- short term memory for digits was poor when read out to him
- but recall was much better when he read them to himself
C - this research supports the idea of one short-term store to process visual info and one for audial info
H - however it could be said his case does not offer good support for the wsm since it is a case study and a unique case of a brain damaged individual so it may not generalise to all memory
P - Dual task performance
E - Baddeley showed that P’s had more difficulty doing 2 visual tasks
- e.g. tracking a light and tracing a letter F
- than doing a visual and verbal task at the same time
- visual –> uses same slave system
- verbal + visual –> separate slave systems#
C - supports the idea for separate slave systems for audial and visual input
P - Lieberman: it is suggested that the visuospatial sketchpad implies that spatial information is first visual
E - but blind people have excellent spatial awareness, although they have never had any visual information
C - VSS should be separated into two different components: one for visual information and one for spatial.
The cognitive interview
- a method of interviewing eyewitnesses
helps them retrieve more accurate memories
4 features of the cognitive interview
- Report everything
- Reinstate the context
- Reverse the order
- Change the perspective
Report everything
- encouraged to include every single detail of the event
- even if it seems irrelevant / they aren’t confident about it
- detail may be important/might trigger other memories
Reinstate the context
- return the original crime scene in their mind
- imagine the environment e.g. the weather, what they could see, etc and their emotions
- 5 senses
- may trigger the recall of context dependent memories
Reverse the order
- recall in a different chronological order
- e.g. end to start or middle to start
- prevents people from filing in the gaps with their expectations of what must have happened rather than the actual vents
- also prevents dishonesty - it’s harder to lie if they have to reverse it
Change perspective
- recall the incident from another person at the scene’s perspective
- e.g. other witnesses or the perpetrator
- disrupts the affect of expectations and schema on recall
The enhanced cognitive interview
- additional elements added to the cognitive interview
- teaching the interview when and when not to establish eye contact
- how to reduce eyewitness anxiety, minimising distractions, getting the witness to speak more slowly and asking open-ended questions
The cognitive interview: evaluation
P - time consuming and expensive
E - takes much more time than the standard police interview
- requires special training that many forces are unable to give the time for
C - this makes it unlikely that the ‘proper’ cognitive interview is actually being used
- explains why police aren’t too impressed by it
P - some elements may be more valuable than others
E - Milne found that a combination of ‘report everything’ and ‘context reinstatement’ produced better recall than any other combinations
- shows that some are more useful
C - strength because if the full interview cannot be used simply just these 2 elements can be used to improve police interviewing and its reliability
P - support for effectiveness
E - metanalysis has found the CI consistently provided more correct information than the standard interview used by police
C - shows that there are real benefits to police using the CI as it gives them a better chance of catching & charging criminals which is beneficial to society as a whole
