Memory Flashcards
What is coding?
How information is stored in the various memory stores
What is capacity?
How much information that can be held in the memory store
What is duration?
The length of time information can be held in the memory
What are the research studies for capacity?
Digit span - Jacobs
Researcher read out a certain number of digits and the participant had to read them back in the same order (this was repeated until they couldn’t do it)
Mean digit span: 9.3
Mean letter span: 7.3
Span of memory/chunking - Miller
Notices that things came in 7’s and found that the capacity of the human memory is 7 items (+/- 2)
Chunking is grouping sets of digits/letters into units
What are the evaluations of capacity studies?
Digit span
+ has been replicated and a valid test of STM
- early study so may have lacked control and participants may have been distracted (confounding variable)
Span of memory/chunking
+ research led to further development about short term memory that is accurate today
- may have overestimated the capacity due to evidence from further research
What are the research studies for duration?
Short term - Peterson + Peterson
Participants had to recall a trigram (3 letters) after counting backwards in different multiples.
After 3 seconds retention was 80%
After 18 seconds retention was 3%
Long term - Bahrick et al
Participants had to recall names of people that they went to school with in their graduating class
Participants tested within 15 years of graduation were 90% accurate from photo recognition but 60% for free recall
Participants tested within 48 years of graduation were 70% accurate for photo recognition but only 30% for free recall
What are the evaluations of duration studies
Short term - Peterson + Peterson
- study used artificial stimuli therefore it lacked external validity
Long term - Bahrick et al
+ high external validity because researchers investigated meaningful info
What are the research studies for coding?
Baddeley
Participants were given a list of words and were asked to recall them in the correct order
Group 1- acoustically similar
Group 2- acoustically dissimilar
Group 3- semantically similar
Group 4- semantically dissimilar
When asked to recall immediately, they did worse with acoustically similar words - suggesting STM is coded acoustically
When asked to recall after 20 mins, they did worse with semantically similar words - suggesting LTM is code semantically
What are the evaluations of coding studies?
+ showed a clear difference between the two memory stores
- used artificial stimuli therefore it does not tell us about coding in different memory tasks so the study has limited application
What is the structure of the multi-store model?
Stimulus -> Sensory register -> STM -> LTM
Who proposed the multi-strore model?
Atkinson and Shiffrin
What is the sensory register?
Memory stores for the 5 senses
Iconic- visual info
Echoic- audio info
Coding-> specific to each store
Duration-> less than half a second
Capacity-> high
Information only passes through the memory system if it is paid attention to
What is the STM?
Coding-> acoustic
Duration-> about 18 secs (unless rehearsed)
Capacity-> 5-9 items
What is maintenance rehearsal?
When we repeat info to ourselves over and over again for it to stay in the STM
What is the LTM?
Coding-> semantic
Duration-> up to a lifetime
Capacity-> unlimited
What are the evaluations of the multi-store model?
Strengths:
Amnesia studies such as HM and Clive Wearing suggest that LTM and STM use different parts of the brain
Limitations:
There is evidence of more than one STM store -> there could be another short term store for non verbal sounds
Prolonged rehearsal is not only needed for transfer to LTM, elaborative rehearsal is also needed (this is when you link information to existing knowledge) so we can use elaborative rehearsal in order for info to be stored in the LTM
Read this PEELC paragraph on evaluations of the MSM
We can use the HM case study to provide evidence for the multi-store model. From research on HM’s brain, his hippocampus was found to be missing as it was removed when trying to help his epilepsy. As a result HM was not able to remember things he had just done but could still remember how to play the piano/write. This suggests that there are different stores of long term memory as suggested in the multi-store model. This is a valuable piece of evidence that supports the multi-store model, as only a part of HM’s brain was damaged, his whole long term memory was not destroyed showing that different parts of the brain code for different functions.
What are the 3 types of LTM?
Episodic
Semantic
Procedural
What is episodic memory?
Store for personal events
Explicit memory
Hippocampus is the part of the brain responsible
What is semantic memory?
Memory for facts and knowledge
Explicit memory
Temporal lobe is the part of the brain responsible
What is procedural memory?
Memory on how to do things -> riding bike/driving Implicit memory (difficult to explain in words) Cerebellum and motor cortex are the parts of the brain responsible