In the multistore model of memory, the stores are static: they just hold information. Information is transferred between the stores by control processes; i.e., information can only enter short term memory if the person pays attention to it while it is in sensory memory (this is the control process of attention); the short duration of short term memory can be extended by the control process of maintenance rehearsal. If information is maintained in short term memory for long enough, it is recoded so that it can be stored in long term memory (see the animation of the multistore model of memory below).
Sensory Memory: Holds information very briefly. Each sensory modality has its own store.
Short Term Memory: Limited capacity, can only store information for a few seconds.
Long Term Memory: Can store vast amounts of information (unlimited capacity?) for very long periods of time.
Control Processes, such as attention and maintenance rehearsal are also an important part of the model. These control the flow of information between the stores.
Sensory Memory
Coding = Modality Specific (can be visual, acoustic, tactile, etc. depending on the sense being used)
Capacity = Difficult to test, thought to be quite large
Duration = 1-2 seconds
Short Term Memory
Coding = Thought to be acoustic (due to studies such as Conrad) but may depend on task (see working memory model)
Capacity = 7 ± 2 items or chunks
Duration = Between 15 and 30 seconds
Long Term Memory
Coding = Semantic
Capacity = Very large
Duration = A very long time, but difficult to test
Evaluation of the Multistore Model
Strengths of the Multistore Model
One strength of the multistore model is that it could be considered high in "face validity". Face Validity concerns whether or not it is a plausible explanation (i.e., does it seem to make sense or fit with our experience). The multistore model makes sense because most people experience only being able to remember some things for a few seconds, and rehearsal seems to enable memories to be stored for longer. Face validity, however, is a weak argument on its own, but a good starting point, so it is important to consider empirical evidence.
Empirical Evidence in Support of the Multistore Model
The 'serial position effect' is a well known phenomena in psychology whereby when people are asked to learn a list of about 20 words read out by the experimenter and are asked to recall them immediately, they tend to remember a some words from the beginning of the list and a few from the end, but tend to forget those in the middle.
The serial position effect supports the Multistore model because it appears that people rehearse the words at the start of the list more times than those later in the list, so they are transferred to long term memory. Words from the end of the list only tend to be remembered if recall is immediately after the list being read out - when they are still in short term memory.
Case study of the brain damaged H.M. also supports the Multistore Model of Memory because following the removal of his hippocampi, H.M. was unable to transfer information from short term memory to long term memory even though he could remember new information for a few seconds and he could also recall information from before his hippocampi were removed.
Weaknesses of the Multistore Model
Case studies of brain damaged participants such as Clive Wearing show that the Multistore Model is an oversimplification of how memory actually works. Clive Wearing suffered brain damage to many brain areas, including his hippocampi, when the herpes simplex virus attacked his brain. Clive was similar to H.M. in that he could not remember new information for more than a few seconds; however, he could learn new skills. This suggests that there is a separate long term memory for skills (Procedural Memory). Clive could also remember facts about his life prior to the illness, but could not remember any experiences. This meant that repeatedly had revelations that he was conscious for the first time. This suggests that there are separate long term memory stores for facts (semantic memory) and experiences (episodic memory).
