The Nature of Memory - Multi-store model Flashcards
what are the components of the multi-store model
- sensory store
- short- term memory store
- Long - term memory store
Define coding
the way that information is transferred into a form it can be store in
define duration
the length of time that the store holds information
define capacity
the amount of information that can be held in a memory store
how is sensory memory coded
through all 5 senses
what is the duration of the sensory memory store
<1/2 a second
what is the capacity of the sensory memory store
unlimited
how is short-term memory coded
acoustically
What is the duration of the short-term memory
18-30 seconds
what is the capacity of the short-term memory store
7+/- 2 items
How is long-term memory coded
semantically
what is the duration of the long-term memory store
a lifetime
what is the capacity of the long-term memory
unlimited
describe a piece research into the duration of STM
Peterson and Peterson 1959
Aim: to investigate the duration of STM when no rehearsal is allowed.
- they tested 24 undergraduates for 8 trials
- on each trial they were given a trigram to memorise
- also given a 3 digit number to count down from in 3’s as a distractor task - prevent mental rehearsal
- asked to stop counting after a set time between 3 and 18 seconds
What is the conclusion of Peterson and Peterson 1959
Conclusion - without rehearsal duration of STM is very short.
what were the results of Peterson and Peterson 1959
- ~ 90% of trigrams were recalled after a 3 second retention interval
- only 10% of trigrams were recalled after a 18 second retention interval
describe a piece of research into the duration of LTM
Bahrick et al 1975
aim: to investigate the effect of prompts on LTM
*392 participants from ohio USA aged 17-74
* year books were retrieved from their high schools
* recall was tested in different ways
- photo recognition ➙ 50 photos from yearbook
or
- free recall ➙ recall the names of their graduating class
what were the results of Bahrick et al 1975
- Photo recognition: participants tested within 15 years of graduation had ~ 90% accuracy. After 48 years they had 70% accuracy.
- Free recall: participants tested after 15 years had an accuracy of 60% and after 48 years this dropped to 30% accuracy.
give a conclusion and an evaluation of Bahrick et al 1975
1 strength
Conclusion - prompts improve accuracy of LTM.
Evaluation - a strength of this research is that it has high ecological validity.
outline a piece of research into the multi-store model
Murdock 1974
- aim: to investigate whether there are separate stores for the short-term and long-term memory
- participants were each read a list of words varying in length from 10-40 words ( each presented for 1-2 seconds)
serial position curve
explain the results of Murdock 1974
The probability of recall was improved at the beginning and end of the list while the ones in the middle were often forgotten.
The improved recall from the beginning of the list is called the primary effect and the improved recall from the end of the list is referred to as the recency effect
serial position curve
give a conclusion for Murdock 1974
- There are separate stores for short term and long term memory.
- the first words and the last words were remembered by the participants due to the primary effect and the recency effect.
- the words in the middle were removed from short-term memory store due to displacement and weren’t held for long enough to be transferred into long term memory.
define primary effect
the first words being transferred into long term memory from the participant being able to rehearse the words.
define the recency effect
the participant having the most recent words stored in their short-term memory store which has a capacity of 7 +/-2 so could only hold the most recent words
What does the serial position curve - Murdock 1974 support
- The serial position curve provides evidence that the there’re separate stores for long-term and short-term memory this is shown by the primary effect and the recency effect.
- The research also supports the concept of the short-term memory having a limited capacity due to the words in the middle of the list being displaced and forgotten.
what did Murdock’s research discover in 1974
The serial position effect
who was HM
he had surgery to remove his hippocampus to relieve his epilepsy.
his memory was assessed in 1955 and he believe it was 1953. He had little recall of the operation and couldn’t remember talking to someone an hour earlier.
His long-term memory never improved with practice, however he performed well on tests of immediate memory span
give a strength of the multi-store model
A strength of the model is that it is supported by evidence such as the HM case study. HM’s amnesia severely affected, his LTM and ability to form LTM yet his STM was unaffected suggesting that they are stored differently.
give a weakness of the multi-store model
STM and LTM arent unitary stores, the model is an over simplfication. Case studies and research such as Tulving 1989 - who performed brains scans proving that different areas of the brain were active when the participant was using different parts of their LTM - and clive waring
Evaluate Peterson and Peterson 1959
1 strength and 1 weakness
- a weakness of this research is that it lacks ecological validity
- a strength of this research is that the finding have been replicated
who came up with the MSM
Atkinson and Shriffin
