The multi-store model of memory · GCSE Psychology

The multi-store model (Atkinson and Shiffrin, 1968)

Information enters sensory memory from the senses. Only what we pay attention to passes to short-term memory (STM).
STM has a small capacity (about 7 plus or minus 2 items) and a short duration (about 18 to 30 seconds without rehearsal). It mainly encodes acoustically.
Information that is rehearsed passes into long-term memory (LTM), which has an unlimited capacity and can last a lifetime. It mainly encodes semantically.
Information is retrieved from LTM back into STM when we need it.

Murdock gave participants lists of words and asked them to recall them in any order.
Words at the start of the list were recalled well (the primacy effect), because they had been rehearsed and passed into LTM.
Words at the end were also recalled well (the recency effect), because they were still in STM.
Words in the middle were recalled least well. This supports the idea of separate STM and LTM stores.

Strengths: evidence such as the serial position effect, and case studies of brain damage, suggests STM and LTM are separate.
Weaknesses: it is too simple (STM and LTM may each have several parts), it overemphasises rehearsal (some things are remembered without it), and much evidence comes from artificial lab tasks.

Multi-store model: A model of memory with separate sensory, short-term and long-term stores.
Capacity: How much information a store can hold.
Duration: How long information stays in a store.
Rehearsal: Repeating information to keep it in STM and pass it to LTM.
Primacy effect: Better recall of items at the start of a list.
Recency effect: Better recall of items at the end of a list.
Serial position effect: The pattern of better recall for the start and end of a list.