STM and LTM Flashcards
define coding
- format in which information is stored in the various memory stores
- can be stored acoustically, semantically or visually
describe Baddley’s 1966 study
- gave different lists of words to 4 groups of participants
-2. asked them to recall them in the correct order
what did Baddley conclude about the STM?
- acoustically similar words were more difficult to recall immediately
- so the STM relies on acoustic coding
what did Baddley conclude about the LTM?
- semantically similar words were more difficult to recall after 20 minutes
- so the LTM must rely on semantic encoding
define capacity
the amount of pieces of information you can hold in your memory
what was Jacobs’ 1887 study?
Digit span Study
describe the Digit Span Study
- read 4 digits, participant repeats out loud
- if correct, researcher reads out 5 digits and so on until participant makes a mistake
state Jacobs’ findings
average amount of
- digits recalled was 9.3 items
- letters recalled was 7.3
explain a weakness of Jacobs’ 1887 Digit Span Study
- carried out in 1887
- early research often lacked controls
- confounding variables may have had an effect
- could reduce validity
define validity
how well a test actually measures what it was created to measure
explain a strength of Jacobs; 1887 Digit Span Study
- replications have found similar results
- for example, Bapp et al’s 2005 replication
- suggests his study is valid in testing STM capacity
explain a strength of Baddley’s 1966 study
- identified a clear difference between 2 memory stores
- as he founded STM and LTM encoded info differently
- provides evidence the stores are different from each other
- helped support MSM
explain a weakness of Baddley’s 1966 study
- the experiment used artificial stimuli
- word lists had no meaning and had no value in everyday life
- when processing meaningful info, people may use semantic coding
what did Miller conclude about capacity?
- capacity of STM is 7 +/-2 items
- we chunk pieces of info together
explain a weakness of Miller’s theory
- he may have overestimated capacity of STM
- Cowan found lower
- Simon found that the size of chunks impact capacity of STM
what did Cowan do?
- 2001, found that capacity of STM is only 4+/-1 chunks
- suggests Miller’s estimation was too high
define duration
length of time that information can be stored in the memory
describe Peterson and Peterson’s 1959 study
-24 students, 8 trials
each student was given a trigram, then a 3 digit number
- had to count backwards from this number until told to stop
(to prevent mental rehearsal)
- each trial told to stop after a certain period (3, 6…18 secs)
what were Peterson and Petersons findings?
- after 3 secs, recall was 80%
- after 18 secs, recall was 3%
- suggested STM duration was 18 secs, unless we rehearse the information
explain a weakness of Peterson and Petersons study
- use of artificial material as stimuli
- ppts asked to recall meaningless material
- problematic, doesn’t reflect everyday memory use
- may mean research isn’t useful in understanding STM duration in regular life
describe Bahrick’s 1975 study
- tested 400 people aged (17-74) on memory of classmates
1. PHOTO RECOGNITION test from yearbook
2. FREE-RECALL, ppts asked to list names from their class
what were Bahrick’s findings for the photo recognition test?
- within 15 years, accuracy was 90%
- after 48 years, accuracy declined to 70%
what were Bahrick’s findings for the free recall test?
- within 15 years, accuracy was 60%
- after 48 years, declined to 30%
what was the conclusion for Bahrick’s 1975 study?
- he found that the LTM’s duration can last a lifetime
explain a strength of Bahrick’s study
- use of personal memories
- recall rates are lower in studies with artificial stimuli
- use of meaningful memories means that Bahrick’s study has high external validity
define the term external validity
the extent to which you can generalise the findings of a study to other situations, people,settings and measures
state a disadvantage of Bahrick’s study
- may be confounding variables
- some participants may look at the yearbook more frequently
state the difference between recall and recognition
RECALL - consciously remembering information without being shown
RECOGNITION - remembering information only after it is shown to us
state what is meant by sensory coding
Sensory coding is a type of code which we use to store sensory information.
state what is meant by visual coding
a type of sensory code which we use to store information about images.
state what is meant by acoustic coding
sensory code which we use to store information about sound
state what is meant by semantic coding
type of code which we use to store information about its meaning
state what is meant by the sensory register
- temporary memory store which holds information from each of our 5 senses
- capacity is huge
- duration is1-2 seconds
- uses sensory encoding (which is modality specific)
state what is meant by the STM
system that processes information while performing an ongoing task
- capacity of 7 +/-2 items
- duration of 18 seconds
- encodes acoustically
