Memory Flashcards
What is cognitive psychology?
looks at internal mental processes to explain behaviour
what is encoding and what are the 3 types
encoding is the form in which the brain handles data
it can be acoustic (inner voice)
visual (minds eye)
semantic (based on meaning)
Draw a diagram of the Multi Store Model
diagram involving -stimulus -sensory register (iconic, echoic, other) -STM (response out) -prolonged rehearsal, maintenance rehearsal -LTM -retrieval
What is the sensory register - its capacity, duration and other points
Sensory registers are the memory store for the 5 senses such as vision (an iconic store) and hearing (an echoic store)
Coding is different for various sensory registers - in the iconic store coding is visual but in the echoic store coding is acoustic
Sensory registers have a very high capacity but hold information for less than 1/2 a second
information from sensory registers only passes further If you pay attention to that info
An experiment to test duration of sensory register
Sperling’s experiment
Procedure:
Sperling flashed 12 letters in a grid on to a screen for a very short amount of time
Test 1: ppts recorded as many letters as they could
Test 2: after the letters disappeared Sperling would request only the letters on one line of the grid
Results of Test 1: 4-5 out of 12 total letters were recorded; about 33%
Results of Test 2: 3 out of 4 letters to recall were recorded; about 75%
Conclusion: This suggests the sensory register was picking up about 75% of the total 12 letters, yet the ppts could not record all 9 letters before the information was lost. This shows the duration is about 1/2 a second long.
The case of HM - who is he and what did the studies show
HM suffered from epilepsy. He had his hippocampus removed from both sides of his brain. The hippocampus is now known to be very important for memory function. His epilepsy stopped, but he lost his LTM. He could not remember the operation or anything since. His LTM was repeatedly tested but never improved. Despite this, he performed well on STM tasks. The study of HM supports the MSM as it provides evidence for having two separate memory stores.
A criticism of the study of HM is that he was a brain damaged patient and so the evidence may not be true for other people (low population validity), weakening his support for the MSM.
Experiment for capacity of STM
Jacobs (1887)
Procedure: Read out 2 letters / digits to ppts and ask them to recall them in the correct order. If they correctly do that move on to 3 letters / digits and so on.
Results: The mean span for digits was 9
The mean span for letters was 7
Evaluation: a very old study and may have lacked adequate control
increasing capacity of STM
MSM
Miller (1956)
capacity of STM can be increased by combining separate bits of information into larger chunks.
Experiment for duration of STM
Peterson and Peterson (1959)
Procedure: tested 24 students who each took part in 8 trials. Each student was given a trigram and then asked to count back from digit in 3’s. On each trial they were asked to stop after a different time interval. This prevented mental rehearsal of the trigram.
Results: the %age of correct responses decreased as the retention interval increased. After 18 secs only 13% was recalled
conclusion: STM has a duration of about 20 secs unless we verbally rehearse the information.
Evaluation: lacked external validity.
experiment for duration of LTM
Bahrick (1975)
Procedure: studied almost 400 Americans. High school yearbooks were obtained and the ppts were tested on:
Test 1: photo recognition where some but not all of the photos were from the yearbook
test 2: free recall where ppts recalled names from their graduating class
Results for test 1: ppts tested within 15 years of graduating had a 90% accurate recall rate. after 48 years recall rate dropped to70%
results for test 2: ppts within 15 years were 60% accurate dropping to 30% after 48 years.
Conclusion: LTM has a lifetime long duration
what is the capacity, duration and coding for the Sensory register, STM and LTM
(MSM)
Capacity: SR: 9 letters (Miller) STM: 5-9 letters LTM: unlimited Duration: SR: 0.5s STM: 20s (Peterson and Peterson) LTM: lifetime (Bahrick) Encoding: SR: different for different registers - visual or acoustic mostly (Sperling 1960) STM: acoustic (Baddeley and Conrad) LTM: semantic, episodic and procedural
Experiment for coding in STM and LTM
Baddeley (1966)
Procedure: gave lists of different words to 4 different groups
group 1: acoustically similar
group 2: acoustically dissimilar
group 3: semantically similar
group 4: semantically dissimilar
Test 1: ppts had to recall the words in the correct order immediately (STM)
test 2: ppts recalled words after 20 mins (LTM)
results:
Test 1 was worse with acoustically similar words suggests STM codes acoustically
test 2 was worse with semantically similar words suggesting LTM codes semantically.
Evaluation: high internal validity - well controlled
low external validity - artificial task
2 types of rehearsal in MSM
Maintenance - maintains information in STM and does not move it to LTM
prolonged / elaborative - adding meaning to information so it can be moved to LTM
study of KF and what he shows about MSM
how does KF support the WMM
Shallice and Warrington (1970) studied KF - a patient with severe amnesia.
His STM was very poor when digits were read aloud to him (acoustic). However it improved when he read the digits out to himself. Further studies showed there could be another STM store for non-verbal sounds. The MSM doesn’t account for separate STM stores for different types of information.
KF couldn’t process verbal information but could process visual information. this suggests his phonological loop was damaged but his VSS was intact. This suggests there are 2 separate STM stores as the WMM shows
Definitions of episodic, procedural and semantic memory.
All types of LTM coding
episodic: memory store for personal events. ‘time stamped’. uses conscious effort to recall.
Semantic: memory for knowledge and facts. has no ‘time stamp’. usually take conscious effort to recall.
procedural: memory store for actions (how to do things) doesn’t use conscious effort to recall.
What is the Working Memory Model?
an explanation of how the STM is organised and how it functions.
developed by Baddeley and Hitch (1974)
WMM has parallel processing
What is the central executive and what does it do
wmm
- Allocates slave systems to tasks
- has no storage capacity
- uses data from sensory memory and/or LTM
- although the model is parallel it processes serially.
What is the phonological loop and what does it do
wmm
It is a temporary store that deals with auditory information. it is divided into two parts:
Phonological store - ‘inner ear’ for sounds (not just speech)
Articulatory process - allows maintenance rehearsal. The capacity of this is 2 seconds worth of what you can say.
What is the Visuo-Spatial sketchpad and what does it do
wmm
it is a temporary store for spatial tasks / visual information. has a limited capacity. it is divided into two parts:
Visual cache - stores visual data
inner scribe - records arrangement of objects in the visual field.
what is the episodic buffer and what does it do
wmm
this was added to the model by Baddeley in 2000. it is a temporary store and combine diverse information ( auditory, visual/spatial and LTM)
it maintains a sense of time sequencing and has a limited capacity.
It links working memory (STM) to LTM and wider cognitive processes.
Experiment to support the phonological loop
Baddeley (1975)
Procedure:
Test 1: ppts given a list of words to remember
test 2: ppts given a list of words and then told to repeat ‘lalala’ (an articulatory suppression task)
results from task 1: ppts find it easier to remember shorter words than longer words (word length effect)
results from task 2: ppts found remembering shorter words just as hard as remembering longer words (no word length effect)
conclusion: the articulatory process has a capacity of 2 secs worth of words. more short words fit into that time limit therefore you remember more short words. however, when given a suppressive task you cannot use the articulatory process (its already in use) therefore there is no advantage to having shorter words. instead of the articulatory process, the episodic buffer is used. this is not specialised so less words are recalled. this shows separate compartments - supporting the WMM
Experiment to show separate slave systems (wmm)
Baddeley (1975)
Procedure:
Test 1: ppts take part in two visual / two verbal tasks simultaneously
test 2: ppts take part in a visual and a verbal task simultaneously
results: it is harder to take part in two tasks that compete for the same slave system.
conclusion: there are separate systems that function separately, but each have a limited capacity
what is interference and the 2 types of it
interference is forgetting because on memory causes another to become distorted or forgotten.
proactive: old info interferes with new info
retroactive: new info interferes with old info
experiment for interference (artificial task)
McGeogh and McDonald (1931)
Procedure: ppts had to learn a list of words until they could recall them with 100% accuracy. they then learned another list:
test 1: synonyms
test 2: antonyms
test 3: unrelated words
test 4: nonsense syllables
test 5: numbers
test 6: none
results: the more unrelated the second list was, the better the recall accuracy
conclusion: interference levels are higher when the information is more similar
experiment for interference (real life task)
Baddeley and Hitch (1977)
Procedure: asked rugby players to name teams they had played week by week throughout the season.
test 1: players who had played every match (may have played 3 matches in 3 weeks)
test 2: players who had not played every match (so may have played 1 match in 3 weeks)
results: accurate recall did not depend on how long ago the matches were (decay over time), but instead on how many matches had been played since.
conclusion: other matches were interfering with recall of a certain match, showing interference occurs in real life situations.
evaluation: good external validity (ecological), low internal validity as it was controlled (may have been confounding variables)
what is retrieval failure and what are the 3 types of encoding specificity principle?
a form of forgetting that happens when we don’t have enough cues available to access the memory. (the memory is available but not accessible unless we have a suitable cue to retrieve it)
there are 3 types of encoding specificity principle developed by Tulving in 1983
- context dependent - external e.g. in a classroom
- state dependent - internal e.g. while drunk
- meaningful link to material e.g. headings
experiment to demonstrate context dependent forgetting
Godden and Baddeley (1975)
Procedure: give deep sea divers a list of words to remember and recall in different contexts
test 1: learn on land, recall on land
test 2: learn on land, recall underwater
test 3: learn underwater, recall underwater
test 4: learn underwater, recall on land
results: where the contexts of learning and recall were different, accurate recall was 40% lower than where they matched.
conclusion: the external cues were different where the context was different and therefore the cues were unavailable, leading to retrieval failure
experiment to demonstrate state dependent forgetting
Carter and Cassaday (1998)
procedure: give ppts a list of words to remember and recall in different states. the anti histamine drugs make them slightly drowsy
test 1: learn on drug, recall on drug
test 2: learn on drug, recall not on drug
test 3: learn not on drug, recall not on drug
test 4: learn not on drug, recall on drug
results: where the contexts of learning and recall were different, accurate recall was much lower than where they matched.
conclusion: the internal cues were different when the state was, and therefore the cues were unavailable leading to retrieval failure.
what is eye witness testimony and what is eye witness memory
EWM: the ability for people to remember events that they have observed (usually crimes)
EWT: the testimony given in court of what an eyewitness observed
what is misleading information, leading questions, post-event discussion and ? (EWT)
misleading information: incorrect information given to the EW after the event. it can be in the form of:
- leading questions: a question which, because of the way it is phrased, suggests a certain answer
- post-event discussion: Eye witnesses discuss what they have seen which may influence the accuracy of each witnesses recall of the event.
experiment for effect of leading questions, and the two explanations
Loftus and Palmer (1974)
procedure: trial 1:students watched film clips of a car accident and were then asked a question;
test 1: how fast were the cars travelling when they hit each other?
test 2: ‘’ contacted
test 3: ‘’ bumped
test 4: ‘’ collided
test 5: ‘’ smashed
trial 2: ppts were asked another question a few weeks later: ‘did you see any broken glass?’
results: the mean speed for each test was calculated. test 2 had a mean of 32 mph. test 5 had a mean of 40 mph.
those in test 5 were much more likely to report broken glass (there was none)
conclusion: there are two explanations:
response-bias - the wording of the question does not affect ppts memories, only how they choose to answer the question.
substitution explanation - the wording of the leading question actually affects ppts memories. (a few weeks later ppts were unlikely to remember the verb asked in trial 1, so response-bias was unlikely)
experiment for post-event discussion (EWT)
Gabbert (2003)
procedure: 2 sets of ppts watched a film of the same crime but from different perspectives
test 1: ppts saw the title of the book stolen
test 2: ppts did not see the title of the book stolen
results: when asked questions before PED, 0% of test 2 said they’d seen the book title. when asked questions after PED, 71% of test 2 said they’d seen the book title.
conclusion: witnesses often go along with each other to win social approval or because they believe other witnesses are right. this is called memory conformity.
