Multi-store Model

Define: Coding, Retrival and Storage

• Coding: the format the information is held

• Storage: the retaining of information in the memory system

• Retrieval: accessing information when it is needed from the memory system

What is the capacity, duration and coding of the sensory register?

• capacity - large capacity

• duration - less than 2 seconds

• coding - sense organs

What is the capacity, duration and coding of the short term memory?

• capacity - limited capacity of 5-9 items

• duration - 18-30 seconds

• coding - acoustically

What is the capacity, duration and coding of the long term memory?

• capacity - unlimited

• duration - lifetime

• coding - semantically

What is displacement?

• When info is pushed out of the STM by other memories because the capacity of the STM is exceeded

What are the processes that happen in the sensory register?

• First gathers information from our sense organs and each sense is encoded differently

• It has a very large capacity

• Sensory register has a limited duration of less than 2 seconds

• If we pay attention to sensory information then it’ll pass to the STM and forgeting is due to rapid decay if no attention is given to it

What are the processes that happen in the short term memory store?

• This has a limited capacity of 5-9 items and a limited duration of 18-30 seconds

• The information in the STM is encoded acoustically

• Maintenance rehearsal is required in order to hold information in the STM otherwise if this does not occur it will be forgotten due to displacement

• Elaborative rehearsal alllows information to be transferred from the STM to the LTM

• chunking is a method of storing more information in the STM where you chunk items together to reduce the number of seperate items

What are the processes that happen in the long term memory?

• This has an unlimited capacity and the duration of up to a lifetime

• LTM encodes information semantically

• Forgetting is due to interference (proactive and retroactive) and retrival failure

Strength of MSM: research support for capacity of STM

• A strength of the MSM is that it has supporting research on the capacity of memory for STM.

• Jacobs used a digit span task where participants were presented with a sequence of digits and had to recall them in the correct order. If they were correct then the they were given a sequence of digits that was one number longer, this was continued until participants were unable to correctly recall the digits in the right order. This is known as the participants digit span. Mean digit span for letters was 7.3 items and for numbers was 9.3 items.

• This supports the MSM as it shows that it accuratly sates the capacity of the STM is between 5-9 items and this is the case for letters and numbers, this increase validity of MSM as a form of memory.

Strength of MSM: Research support for duration of LTM

• A strength of the MSM theory is that it has supporting evidence on the duration of long term memory.

• Bahrick tested participants on their ability to remember students from their high school year group. In one test, participants were given 50 photos (some of the people that were in their year group and others were not) and they had to identify the indaviduals that were in their year group.

• It was found that the ppt that were tested within 15 years of their graduation showed around 90% of recognition accuracy

• When recognition accuracy was tested at a much later date, 48 years after graducation, its still around 70%

• This supports the theory because it shows the duration of long term memory is extremely long and info can be held for many decades and potentially across someones life time.

• This increases the validity of the theory

Weakness of STM: LTM is not a unitary store

• A weakness of the MSM theory is that there is refuting research to show that the LTM is not unitary.

• Clive Wearing contracted a viral infection causing extrensive brain damage. He lost his long term declarative memory. For example he has no memory of his wedding day.

• However, he still has use of his long term procedural memories, e.g. he was still able to play piano.

• This is a weakness as the MSM claims that the LTM store is unitary, however this is contardicted by Clive Wearing who demonstrated the existence of different types of long term memory, thus the store must be split into further compartments as his declarative memory was damaged but his procedural stayed intact.

• This therefore reduces the validity of the MSM theory

Strength of MSM: Research support for coding in STM and LTM

• A strength of the MSM is that there is supporting evidence for the coding in the STM and LTM

• Baddeley gave a group of participants a list of either acoustically similar, acoustically different, semantically similar or semantically different words.

• When participants were asked to recall words immediately after hearing them(using STM), the acoustically similar condition recalled fewer words in order. Furthermore, when participants were asked to recall word when participants were asked to recall words after a 20 minute delay (using LTM), the semantically similar condition had worse recall.

• This supports the MSM as it shows that short term memory codes info acoustically lead to confusion between similar sounding words. Whereas, the long term memory codes information semantically, leading to confusion between words with similar meaning.

• This therefore increases the validity of the theory

What is the primacy and recency effect?

• When learning and immediately recalling a sequence of items, recall of words at the start of the list (primacy effect) and end of the list (recency effect) is much higher than words from the middle of the list

• Words at the start of the list are rehearsed and transferred to the LTM

• Words at the end are still within the capacity of the STM

• Words in the middle are displaced from the short term memory by words at the end of the list

• Shows the STM and LTM are separate memory stores