Theories Of Memory - Multi-Store Model

One of the earliest information processing models of memory is the Multi-Store Model, proposed by Atkinson and Shiffrin in 1968. They proposed that memory consisted of 3 stores: sensory, short-term and long-term. Information is therefore processed in three stages.

Stage 1: Information from the environment is received by the sensory store. There is one sensory store for each of the five senses. Information lasts for a very short period of time (1/4-1/2 second) in these stores. If the information is not paid attention to, it is quickly displaced by new, incoming information.

Stage 2: The information that is attended to then passes into the short-term memory store where it is stored acoustically (by sound). The STM only has the capacity for 7+/-2 (so 5-9) auditory and 7+/-2 visual items at any one time. Information is lost on a FIFO (first in, first out) or it decays within 30 seconds if it is not rehearsed. STM is very fragile and information is lost very easily.

Stage 3: Information can only pass into the long-term memory through the rehearsal loop, and the more something is rehearsed, the stronger the memory trace in the LTM is. As far as we know, the  LTM holds information indefinitely, and has an unlimited capacity. Information is stored semantically (by meaning).

A lot of evidence for the distinction between LTM and STM comes from the study of amnesiacs and brain damage patients e.g. Scoville & Milner, the case of 'HM' (1957) HM suffered severe epileptic seizures that were not effected by medicine, so doctors removed his hippocampus in 1953, which lessened the seizures but removed his ability to form LTM. He remembered skills he’d previously learnt, but he always remained 23 in his mind.
 The fact that some types…