Memory Flashcards
Describe short-term memory (STM)
-acoustically coded
-limited capacity of approx 5-9 items
-duration of approx 18-30s
Describe long-term memory (LTM)
-semantically coded
-unlimited capacity, permanent store
-duration up to a lifetime
What is coding?
The format in which information is stored in various memory stores
Who did research on coding and when?
Baddeley 1966
Describe the procedure and findings of Baddeley’s research into coding
Gave different lists of words to 4 groups
1. acoustically similar
2. acoustically dissimilar
3. semantically similar
4. semantically dissimilar
Asked to recall the words in order
immediate recall (STM) was worse when acoustically similar- STM coded acoustically
after 20 minutes (LTM) recall was worse when semantically similar- LTM coded semantically
What is a strength and a weakness of Baddeley’s research into coding?
Identified clear difference between stores
-STM mostly acoustic
-LTM mostly semantic
-stood test of time
Helped understanding of memory leading to the MSM
Lacks mundane realism
-artificial stimuli with no personal meaning
-doesn’t say anything about memory in real life
-more meaningful STM may be coded semantically
Limited application
What is capacity?
The amount of information that can be held in a memory store
Who did research on capacity and when?
Jacobs 1887
Miller 1956
Describe the procedure and findings of Jacobs’ research into capacity
Researcher read out digits, adding one each time until the participant repeats it back in the incorrect order
Digit span for digits is 9.3 but 7.3 for letters as a mean
Describe Miller’s research into capacity
Found that things come in 7s (eg: days of the week, musical notes)
STM capacity is 7±2
Can also recall 5 words as easily as 5 letters via chunking
What is chunking?
Grouping sets of digits/letters into units/chunks
What is a strength and a weakness of research into capacity?
Jacobs’ research replicated
-although at time lacked adequate control over EVs and CVs
-so digit span may have been underestimated due to distraction
-but results confirmed by a controlled study by Bopp and Verhaeghen
Valid
Miller may have overestimated the STM capacity
-Cowan 2001 replicated concluding 4±1 chunks
Lower end of Miller’s estimation is more appropriate
What is duration?
The length of time information can be held in memory
Who did research on duration and when?
Peterson and Peterson 1959
Bahrick et al 1975
Describe the procedure and findings of Peterson and Peterson’s research into duration
24 students each in 8 trials with different retention intervals (3, 6, 9, 12, 15, 18)
In each trial they were given a consonantal trigram, and then had to count backwards from a 3-digit number to prevent mental rehearsal
After 3s, recall 80% accurate
But after 18s, recall 3% accurate
STM duration is 18s unless verbal rehersed
Describe the procedure and findings of Bahrick et al’s research into duration
392 Americans had their high school yearbooks obtained
Tested for photo recognition and free recall
Within 15y of graduation, photo recognition 90% accurate, but 70% after 48+y
Within 15y of graduation, free recall 60% accurate, but 30% after 48+y
Shows LTM may last up to a lifetime for some material
What is a strength and a weakness of research into duration?
Bahrick et al’s research has high external validity
-measures meaningful memories
-recall is lower for meaningless memories, shown by Shepard
Reflects more real estimate of LTM duration
Peterson and Peterson use artificial stimulus
-doesn’t reflect everyday memory activities with meaningful material
Lacks external validity
Who created the multi-store model of memory and when?
Atkinson and Shiffrin 1968
What is the multi-store model of memory?
3 unitary memory stores where information is transferred between them in a linear sequence to possibly become a memory
Describe the sequence of the multi-store model of memory?
Stimulus from environment –> sensory register –> STM —> LTM
What is on the arrow from the sensory register to the STM in the MSM?
Attention
What is on the arrow within the STM and to the LTM in the MSM?
STM- maintenance rehearsal
STM->LTM- prolonged rehearsal
What is on the arrow from the LSM to the STM in the MSM?
Retrieval
What is the arrow pointing downwards from the sensory register in the MSM?
Decay