The Multi-Memory Store
The Multi-Store Model (Atkinson and Shiffrin, 1968)
Atkinson and Shiffrin suggests that there are three stores of memory:
Information is detected from the sense organs (sight, smell) and then goes into the sensory memory.
If attended to it would then go into the Short-Term Memory (STM)
Information is then transferred from the STM to the Long-Term Memory if rehearsed
When rehearsal doesn't occur it can be displaced or decay happens in the STM-the information is forgotton
Each store differs in its: Capacity, duration and encoding
Short-Term Memory capacity
Procedure: The experiment "Millers Magic Numbers" saw participants being subjected to a number of auditory tones varying in pitch. They were asked to recall the tones but after 5-6 they began to get confused, their ability to recall anything else broke down.
Conclusion: Short-Term memory can hold 7 +/- 2 items. He also said the same for individual letters and digits. Information can also be chunked -we remember more letters if they are in words.
Stated that the capacity of STM was roughly what could be reheared in 2 secounds
Criticism: works for words but not faces, music and pictures
Short-Term memory duration
Peterson and Peterson (1959):
- A participant is presented with a set of 3 numbers
- Asked to count backwards in 3's from 100
- They were asked to recall the numbers every 3 seconds up to 18
After 3 seconds, recall was 80% correct, but after 18 seconds, recall was only 10% correct.
Information can be lost quickly if it's not rehearsed
Short-Term memory and Long-Term Encoding
4 groups were allocated 4 conditions of words: acoustically similar (sounds the same), acoustically dissimilar, semantically similar (same meaning) and semantically dissimilar
They were then presented with 5 words from their category and asked to recall the list correctly immediately after.
Acoustically similar words was the hardest to recall with only 55% accuracy whilst semantically similar words was easier to remember.
Sound is important to short term memory encoding. However, this can't be the only way we encode. What about faces? He also concluded that the Long-Term memory mainly uses semantic encoding.
Criticism: low eco validity (people don't recall lists in everyday life) and these are not the only ways we encode
Long-Term Capacity and Duration
Capacity and duration:
Limitless capacity and duration (difficult to test)
Study to test capacity:
- 400 participants were put through 3 tests (visual, verbal and free recall)
- 50 pictures were put up and the graduates and to recall their ex friends
- A name recogision test
- Free recall
- 15 years after graduation, participants were 90% accurate in recalling names and faces
- 48 years later they were 80% accurate in recalling names and faces