Atkinson and Shiffrin (1972) proposed a theory that views the human memory system as being made up of three separate stores
Memory model
Sensory Store
stimuli from our environment (smells, sights, tastes, sounds) enter the sensory store whether the person is paying attention to the source or not. If we do not pay attention then the information decays. Information is held for a brief amount of time (2 seconds). Information is encoded by our separate senses.
Short-term memory: if attention is paid attention to in the sensory store then it moves to the STM. This has a limited capacity (7 +/- 2 chunks). This is Millers magic number seven. Information can remain in the STM for up to 30 seconds. If the information is not transferred to LTM then it decays (memory fades). We rehearse information in our STM by process of maintenance rehearsal and it allows information to be moved into LTM. The encoding is mainly auditory. Capacity of STM can be increased by chucking information – e.g. when learning a phone number 01632-345-667.
Long-term memory
this has both unlimited duration and capacity (could potentially last forever). The encoding in LTM is mostly semantic (we think about the meaning of the information). Encoding can be visual and auditory.
