memory Flashcards
define memory
process by which we retain and recall information about events that have happened in the past
define capacity
amount of information that can be stored
define duration
length of time information can held in the memory store
define coding
format in which the information is stored in the memory stores
different types of coding stores
iconic- visual
echoic- auditory
haptic- touch
gustatory- taste
olfactory- smell
2 ways information can be coded
acoustic - sounds
semantic- meaning and experience
define sensory register
temporarily stores information from our senses
features of sensory register
- unless we pay attention it disappears though spontaneous decay
- unlimited capacity
- very limited duration
- information is coded depends on the sense that picks it up
crowder (1993) research on coding in sensory register
provided information in different forms- verbally and visually
- found that information retained for a few milliseconds by iconic store, but 2-3 seconds by echoic
-there are different stores with different coding
sperling (1960) research on capacity of sensory register
flashed 3x4 grid of letters for 1/20th second and asked participants to recall on row depending on pitch played afterwards
- recall was 76% accurate showing sensory register is nearly unlimited
sperling (1960) research on duration of sensory register
varied time 0.3s and 1s tone was played after the grid
- 50% accurate with 0.3s
- 33% accurate with 1s
- concluded duration of sensory register is only about 1s
define short term memory
memory for immediate events which disappear if not rehearsed
features of short term memory
- limited capacity and duration
- acoustic coding
- maintenance rehearsal (verbal) allows the information to remain in STM
- can be forgotten through decay or displacement
jacobs (1987) research on capacity of STM
tested their ability to remember a string of letters or numbers, and if they recalled 50% accurately, he would increase the number of items until they reached their capacity
- average 9.3 numbers and 7.3 letters
- concluded it is easier to recall digits as there are less of them
miller (1956) research on capacity of STM
asking to remember a string of numbers/letters
- we can recall 7 plus or minus 2 items
- we can chunk to remember more
define chunking
putting things together to make it easier to remember and remember less
evaluation of Sperling (1960) for duration and capacity of sensory register
+ highly scientific
- lacks ecological validity
evaluation of Jacob’s (1987) on capacity of STM
- artificial and lacks ecological validity
baddeley (1966) research on coding
- asked participants to recall 5 or 10 words from a group of 4 different groups
- acoustically or semantically, similar or dissimilar
- recalled straight after for STM or 20 mins later for LTM
- concluded acoustically similar was hardest to recall for STM so it has acoustic coding
- concluded semantically similar was hardest to recall for LTM so it has semantic coding
evaluation of baddeley (1966) research on coding
- lacks ecological validity, does not consider other coding (Brandimole et al- visual coding, Frost- visual coding) or types of LTM, no control over participants variables
peterson and peterson (1959) research on duration of STM
24 undergraduate students took part in 8 trials where they were given a consonant trigram to remember and a 3 digit number to count down in 3s from
- changed retention interval 3,6,9…18
- 90% after 3s, 20% after 9s, 10s after 19s
- concluded STM has limited duration of up to 18s when rehearsal is prevented
evaluation of peterson and peterson (1959) research on duration of STM
- lacks ecological validity, lack internal validity as it may be measuring displacement if memory as STM reached capacity
wagenaar (1986) research on the capacity of LTM
created a diary of 2400 events over 6 years and texted himself on recall of events
- concluded capacity is extremely large as he recalled majority of events
define case study
very detailed investigation of an individual or small group of people
evaluation of wagenaar (1986) on capacity of LTM
- might not the tell the truth
- demand characteristics
- less objective to yourself
bahrick et al (1975) research on duration of LTM
opportunity of 392 ex american high schoolers between 17-74 years and were asked to name old classmates from yearbook either by free recall (name as many names) or photo recognition
- photo- after 15 years 90%, after 48 years 70%
- free recall- after 15 years 60%, after 48 years 70%
- concluded LTM has unlimited duration
evaluation of bahrick et al (1975) on duration of LTM
+ has high ecological validity
- confounding variables, practice effects
what is the multi store model
made by atkinson and shiffrin (1968) which explains memory passing through sensory register, to STM and then LTM
define long term memory
memory of past events
features of LTM
- unlimited capacity and duration
- semantic coding
- elaborative rehearsal converts it into LTM
- can be forgotten through interference from similar memories or retrieval failure
evaluation of MSM strengths
- different duration, capacity and coding for all stores
- brain scanning supports that prefrontal cortex is active during STM and hippocampus during LTM
- HM has hippocampus removed but he can still create STM but couldn’t make new LTM
-process of maintenance rehearsal is correct
evaluation of MSM weaknesses
- STM relies on LTM when chunking so doesn’t always have linear sequence
- STM is not unitary as when studying KF (amnesia) they were able to recall better through iconic than acoustic store
- LTM is not unitary as there is more than one type
- memories can be transferred without rehearsal like smells
- criticised for emphasis on maintenance rehearsal as deep processing is more important and memorable
define primacy effect
words are better recalled at the beginning as it had been rehearsed and transferred to the LTM
define recency effect
last few items can be recalled better as they have displaced previous ones and is in STM
Glanzer and Cunitz (1966) research in serial position effect
words at beginning and end were recalled better due to primacy and recency effect
define explicit memories
declarative because it is easy to put into words
episodic and semantic
define implicit memories
non declarative as it is not easy to put into words
procedural
define episodic memory
information about events you have actually experienced
features of episodic memory
- time stamped
- certain emotions can affect strength of the memory like trauma
- have to make conscious effort to recall
define semantic memory
facts and knowledge that we have learnt and can consciously recall
features of semantic memory
- strength of semantic memories are positively associated with the degree of processing
- linked to episodic memories
- not time stamped
- can gradually move from episodic to semantic
define procedural memory
knowledge of how to do things that are unconsciously recalled like walking
features of procedural memory
not time stamped
strengths of the types of long term memory
- HM could still form new procedural memories even though his hippocampus was removed but not semantic or episodic
- difference between declarative and non declarative memories
- brain scans how different LTM in different parts of the
where in the brain are the different types of LTM functioning
- episodic- hippocampus, frontal lobe, temporal love
- semantic- frontal lobe
- procedural- cerebellum, motor cortex, basal ganglia, limbic system
weaknesses of the types of long term memory
- areas may act as relay stations which information has to pass through
- studying people with brain damage makes it hard to pinpoint behaviour on it
- other styles of LTM like perceptual- representation system (PRS) or priming
what is the working memory model
representation of how STM is organised and functions, proposed by Baddeley and Hitch (1974)
central executive, phonological loop, visuo- spatial sketch pad, episodic buffer
features of central executive
- coordinates the activities of all 3 sub systems
- acts as a filter to send information to the right place
- directs attentions to slave systems and collects responses
- can balance and switch attention
- cannot attend to too many things at once and has no capacity for storage
features of phonological loop
- processes information in terms of sounds
- preserves order in which information arrives
- phonological store- stores words you hear (inner ear)
- articulatory process- user for words that are heard or seen and allows maintenance rehearsal (inner voice), 2s capacity, turn written into words
- limited capacity
features of visuo-spatial sketch pad
- processes visual and spatial information (inner eye)
- Logie (1995) divided into visual cache (store visual data) and inner scribe (records arrangement of objects in a field)
- 3-4 chunks
feature of episodic buffer
- added in 2000
- temporary general store that brings together material from the other slave systems into a single memory
- limited capacity of 4 chunks
- bridge between working memory and long term memory
evaluation of WMM strengths
- KF shows STM is subdivided because he had poor ability for verbal information but not visual, so his phonological loop was damaged
- Baddeley et al found it hard to do two visual tasks than visual and verbal so there must be separate systems
- doesn’t put heavy emphasis on rehearsal and can explain why somethings go to LTM without rehearsal
- central executive is present and working in brain (prefrontal cortex)
evaluation of WMM weaknesses
- central executive is too vague and simple as Eskinger and Damasio suggested it could be subdivided
- lacks ecological validity as majority has been lab studies
define forgetting
failure to retrieve memories
what is interference theory
information in LTM becoming confused with or disrupted by other information during coding, leading to inaccurate recall
define proactive interference
works forward in time when information stored previously interferes with an attempt to recall something new
Underwood (1957) study on proactive interference
if people had previously learnt 15 or more word lists during the same experiment, a day later their recall of the last word list was 20%
if they hadn’t learnt any earlier lists, recall was 80%
define retroactive interference
works backwards in time when new information disturbs informations stored previously
Muller and his student (1900) study on retroactive interference
gave participants a list of nonsense syllables to learn for 6 mins and after a retention interval asked them to recall
recall was poorer if participants had been given an intervening task
evaluation of interference theory strengths
- research in laboratories allows for more control over extraneous variables
- real world application as Baddeley and Hitch (1977) asked rugby players to recall names from a rugby season and less names were recalled if they played all games
- real life application with advertising as Danaher et al (2008) found that recall of two competing brand were inspired so it has marketing advantages
evaluation of interference theory weaknesses
- some people are less affected by proactive interference as Kane and Eagle (2000) found people had different WM spans so findings can’t be generalised to everyone
- low ecological validity
- interference effects do not occur often in everyday life as memories need to be similar
- doesn’t help to understand the conflictive processes
what is retrieval failure
absence of cues leads to information being inaccessible
define encoding-specificity principle
for a cue to be helpful it needs to be present at encoding and retrieval
factors determining effectiveness of a cue
- how overloaded it is
- how deep the processing is
- how well the cue fits the information (similar)
define context dependent forgetting
occurs with external retrieval cues with forgetting when external environment is different at recall
define state dependent forgetting
occurs with internal retrieval cues with forgetting when internal state is different at recall
studies that show context dependent forgetting
- Abnerthy (1940) where students did a test either with their normal instructor or not and in their normal testing room or not
- Godden and Baddeley (1975) asked scuba divers to learn a set of words on land or underwater, recall on either
studies that show state dependent forgetting
goodwin et al (1969) asked male volunteers to remember a list of words when drunk or sober, and recall the lists in either condition after 24 hours
tucking and pearlstone (1966) study on retrieval failure
participants learnt 48 words belonging to 12 categories, with category followed by word, and either asked for free or cued recall
- 40% free recal
- 60% cued recall
- evident that cues help recall
retrieval failure evaluation strengths
- lots of evidence to support
- has high ecological validity bad it has real life application
- retrieval failure may be the main reason for forgetting and can explain interference effects- Tulving and Psotka suggested interference effects are due to absence of cues
retrieval failure evaluation weaknesses
- cues are not always useful especially with complex information so there shouldn’t be a big emphasis on it (outshining hypothesis)
- low ecological validity as they are lab studies
- might not explain all types of memory like procedural
define outshining hypothesis
cues effectiveness is reduced when better cues are present
define eyewitness/ earwitness testimony
the ability of the person who saw or heard the crime to remember the details of the event
process of information encoding into an eyewitness
- witness encodes into LTM details of the event, which may only be partial and distorted
- witness retains the information for a period of time, and it may be lost or modified
- witness receives the memory from storage and the precedence or absence of cues and nature of questioning may affect the accuracy of what is recalled
factors affecting the accuracy of eye witness testimony and definitions
- misleading informations- information that suggests a desired response
- leading questions- questions that increase the likelihood that an individual will give a desired answer
- post event discussion- misleading information being added to a memory after an event due to discussion with other people
- anxiety
loftus and palmer (1974) extent to which participants estimated of speed would be influence by misleading questions
- 45 students were shown 7 video clips of car crashes and asked to write down what they saw and answer questions
- smashed (40.8mph) fastest and contacted (31.8mph) slowest
- as intensity of verb increased, so did estimation which altered participants perceptions
loftus and palmer (1974) how responses change what participants remember seeing
- 150 participants watched a one minute film of a car driving and being in a traffic accident
- 50 were asked a question with “smashed” and 50 were asked with “hit”
- a week later they were asked if they saw any broken glass even though there wasn’t any
- 16 people said yes if their key word was smashed compared to 7 for hit and 6 for control
define response bias explanation
wording influences how they will answer
define substitution explanation
wording changes participants memory
gabbert et al (2003) investigated the effects of post event discussion
- participants were in pairs were each partner watched a different video of the same event and one condition whrte encouraged to discuss the event with each other
- 71% of participants mistakenly recalled but picked up from discussion
- 0% mistakenly recalled in control
- memory conformity- witnesses of along with each other
define confabulation
addition of false details to a memory of an event
strengths of misleading information affecting ewt
- considerable research supporting
loftus used fake advertising about Disneyland which constrained misleading information of characters (Bugs Bunny and Ariel) which were not present and participants were asked if they had shaken hands with them) - application to criminal justice system to identify and investigate into crimes
weaknesses of misleading information affecting ewt
- often use the same young audience meaning findings cannot be generalised
- demand characteristics
- artificial tasks which lack ecological validity and are not emotionally arousing
foster et al (1994) found that if participants were watching a real life burglary and thought their responses will influence a trial, their identification was more accurate
define anxiety
state of emotional and physical arousal which can both have a positive and negative effect on accuracy
johnson and scott (1976) study into weapon focus effect
- participants were left in the waiting area outside a lab waiting for the real study to start and a low anxiety and high anxiety situation took place
- low anxiety– overheard discussion about equipment failure and man walked out with a pen.
– high anxiety – overheard heated discussion with breaking glass and crashing chairs and man walked out with a bloody paper knife
– 49% correctly identified man holding pen, but only 33% could identify the man with the knife 
define weapon focus effect
the weapon distracts attention from other features and reduces accuracy of identification 
define evolutionary argument
it would be adaptive to remember events that are emotionally important so you could identify similar situations and recall how to respond
yuille and cutshall (1986) investigated into a real life shooting and how anxiety has a positive effect on recall
– they interviewed 13/21 witnesses at the scene of the shooting in a gun shop in Canada 4 - 5 months after their original police interview
- witnesses were very accurate in their accounts and there was little change in the amount of accuracy after five months.
– highest levels of stress where most accurate (88%)
christiansen and hubinette (1993) also looked into how anxiety improved recall
- 58 witnesses of 22 real life bank robberies in Sweden were interviewed, some with low anxiety like on lookers and some with with high anxiety like those directly threatened.
– witnesses were generally 75% accurate, especially those most anxious
define yerkes- dodson effect
there has to be a moderate amount of anxiety for EWT to be enhanced
anxiety evaluation strengths
+ lab studies are valid as they are supported by most real life studies
anxiety evaluation weaknesses
- ethical issues of psychological harm
- real life studies cannot be controlled due to extraneous variables
- weapon focus effect can be due to surprise rather than anxiety
Pickel (1998) got participants to watch a thief walk into a hairdressers with scissors, wallet, gun or raw chicken- identification was least accurate with high surprise objects - doesn’t take into account emotional sensitivity and individual differences like neurotic and stable people
- catastrophe theory- psychological arousal beyond optimum level causes catastrophic decline in performance rather than inverted-u
other factors affecting eyewitness testimony
duration of event and time of day- longer we watch the more likely we are to remember details, witnesses remember more from the day as you can see more
violence distraction- when shown a violent and non violent film, participants remembered more details from the non violent one
amount of time between event and recall- longer the time, worse the recall due to trace dependent forgetting
age of witnesses- older people are more likely to be misled by misleading questions, younger people remember the source of information more accurately and are less likely to pick up information after event
problems with standard interview
- revolves around the interviewer where they do most of the talking
- questions are predetermined following a written checklist
- may ask leading questions to confirm their beliefs about the crime
- discussions during the interview may contaminate a witness’ memory
features of cognitive interview and how they improve accuracy
context reinstatement- witnesses should return to the original crime scene in their mind and imagine the environment- helps recall how you felt and the enviornment can trigger retrieval cues
report everything- include every single detail of the event even if they seem irrelevant- witnesses might not realise that some details are important and may trigger other important memories that are connected
reverse the order- events should be recalled in a different chronological order to the original sequence- prevent people from reporting expectations using schemas and prevents dishonesty as it is harder to recall backwards
change perspective- recall coincident from the perspective of someone else- disrupts expectations and schemas on recall
extra features of enhanced cognitive interview
- interviewer does not distract the witness with unnecessary interruptions and questions
- witness control the flow of information
- ask open ended questions
- getting the witness to speak slowly
- witness reminded not to guess and say “don’t know” if necessary
- reduce anxiety in witness
cognitive interview evaluation strengths
- a lot of supporting research, where a meta analysis of 53 studies showed that there was a 34% increase in the amount of correct information
- increase quantity of information
- useful when interviewing older witnesses- study with group of older participants (mean age 72) and younger (mean age 22) where interviewed after watching a simulated crime using either standard or cognitive where cognitive interview produced more information, and the strength was greater for older participants
cognitive interview evaluation weaknesses
- more information also lead to more incorrect information- 81% increase in correct information also has 61% increase in incorrect information
- time and training for police officer to carry out cognitive interviews
- not all police forces use full cognitive interview process, like Thames Valley police leave out “ changing perspective” which makes it hard to evaluate as a whole
-some factors like context reinstatement and report everything are more important
