multi store Memory Flashcards
who was the Multi-Store Model devised by
The Multi-Store Model of Memory was devised by Atkinson and Shiffrin in 1968.
What is coding?
Coding is which format the information is stored in.
What is capacity
Capacity is how much of information that can be held in the memory store at any one time.
What is duration
Duration is how long information stays in the memory store.
What does function mean
Function is what each store does.
Sensory Register:
The mind is flooded with environmental stimuli coming from the eyes, ears, taste receptors, touch receptors ..etc.
This information arrives at the Sensory Register. The information enters and is coded in the sensory register in whatever form it was perceived in (so it is modality specific) and each kind is stored in a different store within the sensory register depending on which sense organ the information came from. Visual memory is stored in the Iconic store, sound in the Echoic store, smell in the Olfactory store, touch in the Haptic store, and taste in the Gustatory store. As there is a lot of stimulus coming in all the time the capacity of the sensory register is unlimited. As most of the sensory information that comes in doesn’t need to be consciously considered, and there is a lot of it, the duration of for sensory memory in the sensory register is only about 250 milliseconds.
Only sensory information that we pay attention to will move to the next store, and so the vast majority will be lost.`
Short term memory:
Short Term Memory store is the next store. It has a duration of about 18-30 seconds. Only information that is rehearsed (consciously repeated inside the mind) here will pass into the next store, and the rest will be lost, as by rehearsing information we can keep it in the store for longer than 18-30 seconds. Short term memory is coded acoustically as the information is rehearsed using our internal voice.
There are two kinds of rehearsal. Maintenance rehearsal keeps the information in the short term memory for longer, and it may pass into the long term memory eventually. Elaborative rehearsal is where we semantically encode the information (give it meaning), moving it directly from the short term memory to the long term memory.
Chunking is a way to improve short term memory by grouping items so that each group is treated as one item by the short term memory, thus improving recall as the overall number of ‘items’ is reduced.
Long term memory:
Information in the long term memory has an unlimited duration and it has an unlimited capacity. Information in our long term memory may be lost (we lose access to it), but this may be regained at a later date. Information in the long term memory is coded semantically (based on its meaning).To use the information in the long term memory we need to bring it out of the long term memory and back into the short term memory. This process is called retrieval.
Unlike the short and long term memory the sensory register is not under conscious control; it is recorded automatically. Any information found in the short or long term memory is initially gathered by the sensory register.
Research on sensory register
Capacity- Sperling (1960) flashed a grid of 20 letters onto a screen for a 20th of a second. When participants were asked to recall random rows of letters the recall was strong. This suggests that all the rows of letters were stored in the sensory register as participants didn’t know which row would be asked for, meaning that the iconic store in the sensory register has a large capacity.
Research on shorty term memory
Coding- Baddeley (1966) gave four 10 word lists to four participant groups. The first list consisted of acoustically similar words (words that sound similar). The second list consisted of acoustically dissimilar words (words that sound different). The third list consisted of semantically similar words (words with similar meanings), and the fourth list consisted of semantically dissimilar words (words with unrelated meanings). Baddeley found that immediate recall was worst for list 1, and recall after 20 minutes was worst for list 3. This suggests that information in the short term memory is coded acoustically, meaning that immediate recall for list 1 was hardest because the words all sounded similar, so they were all effectively stored as one item, making recall difficult.
Capacity- Jacobs (1887) presented participants with a list of letters or numbers. Participants then had to recall the list in order. Jacobs found that the capacity for letters was around 7 items and 9 for numbers, suggesting that the capacity of the short term memory is very limited.
Duration- Peterson and Peterson (1959) showed participants 3-letter trigrams (i.e: HFR, TKD). Trigrams with any meaning were avoided so that participants could not rehearse the information semantically. Then participants had to count backwards for a few seconds. This interference task was designed to stop maintenance rehearsal. Peterson and Peterson found that after 18 seconds recall was less than 10%. This suggests that information remains in the short term memory for only a few seconds before it disappears.
Research on long term memory
Capacity- Wagnaar (1986) kept a diary over the course of six years which recorded over 2,400 events. He tested himself on the events and found a 75% recall after 1 year and a 45% recall after 5 years, suggesting that the capacity of the long term memory is very large, potentially limitless.
Duration- Bahrick (1975) showed old photographs and names (including those of old school friends) to participants aged 17-74, recall was 90% after 15 years, and still 80% for names after 48 years. This suggests that the duration of the LTM is very large, potentially limitless.
Evaluation of the Multi-store Model
•Some research into STM duration has low mundane realism, as the stimuli participants were asked to remember bear little resemblance to items learned in real life, e.g. Peterson and Peterson (1959) used nonsense trigrams such as ‘XQF’ to investigate STM duration. Similarly the ecological validity of many of the experiments is low as they were carried out in lab environments, so participant behaviour may not be the same as would be expected in a more natural environment. This can lead to low external validity for the findings.
•There is a large base of research that supports the idea of distinct STM and LTM systems. An example of this is the Shallice and Warrington (1974) study of KF, a brain-damaged case study patient whose STM was impaired following a motorcycle accident, but his LTM remained intact.
•The model is arguably over-simplified, as it sees each store as a single unit, but evidence suggests that there are multiple short and long-term memory stores, e.g. ‘LTM’ can be split into Episodic, Procedural and Semantic memory.
