Before we focus on the key characteristics of the Multi-Store Model of Memory it is important to develop an understanding of the definition of ‘memory.’

AO1, Definition of ‘Memory’: The process by which we retain information about events that have happened in the past. This includes fleeting (short term) memories as well as memories that last for longer (long term). Research has identified a number of key differences between short-term memory (STM) and long-term memory (LTM) in terms of the way these types of memory work.

A model of memory is a theory of how the memory system operates, the various parts that make up the memory system and how the parts work together. The Multi-Store Model of Memory as developed by Atkinson and Shiffrin describes the key characteristics of memory including; the sensory store, short term memory store and long term memory store.

AO1, Description The Multi-Store Model (MSM) of Memory: Atkinson and Shiffrin

The most well-known and influential model of memory was put forward by Atkinson and Shiffrin in 1968. They proposed that human memory involved:

• A flow of information through an information processing system.
• A system divided into 3 stages or storage components i.e., Sensory Register (SR), Short-term Memory (STM) and Long-term Memory ( LTM).
• Information passing from one stage to another in a fixed sequence.
• Constraints (or restrictions) at each stage in terms of capacity (size, i.e., how much each stage can hold), duration (length of time the memory stays in each stage) and coding (the way the information is stored at each stage e.g., visual images or sounds).

There are three limitations (or constraints) to the separate memory stores which are:

(1) Coding: The way that information is represented in the memory store (e.g., by sound [auditory], meaning [semantic] or image [visual]).

(2) Duration: The length of time that memories can be held within the memory store.

(3) Capacity: The amount of information that can be held in the memory store at any one time.

The Multi-Store model of Memory (MSM), AO1, Description:

According to Atkinson and Shiffrin:

• The sensory store is constantly receiving information from the environment. Most of this information receives no attention and so is lost through However, if the information that enters the sensory stores is attended to (paid attention) then this information is encoded and passes through to the short term memory (STM).
• Once in the STM, information (if not rehearsed), can be lost through either displacement (this is because the STM has a capacity of 7+/- 2 items) or decay (as the STM only has a duration of 0-18 seconds).
• If information is elaborative rehearsed (over and over ) and the information is understood, then the information will be transferred /encoded into the long term memory (LTM).
• The LTM can hold information for an unlimited about of time and has an unlimited capacity.
• When stored information is needed, it can be retrieved from the LTM back to the STM.
• Atkinson and Shiffrin proposed a direct link between rehearsal in the STM and the strength of the long term memory.

Evaluation, AO3 of The Multi-Store Memory Model

Strengths:

(1) Point: Further research from brain scanning techniques has supported the Multi-Store Memory model and the idea of separate memory stores (i.e. a short term memory store and a long term memory store. Evidence: Squire et al (1992) used brain-scanning techniques and found that STM can be associated with activity in the prefrontal cortex and that LTM can be associated with activity in the hippocampus. Evaluation: This is a strength because it provides biological evidence that the different types of memory are processed by different parts of the brain and that the memory stores are distinct as the multi-store model suggests.

(2) Point: Case studies of brain damaged patients (e.g. KF) have also offered support for the Multi-Store Model of memory. Evidence: Shallice and Warrington (1970), reported the case of KF, who was brain damaged as a result of a motorcycle accident. His STM was severely impaired, however his LTM remained intact. Evaluation: This supports the view that STM and LTM are separate and distinct stores and therefore supports the proposals of the Multi-Store Model of memory as it shows that it is possible to damage only one store in memory.

(3) Point: The main strength of the MSM come from support for the idea that at least two separate memory stores do exist (i.e. STM and LTM). Evidence: Murdock’s (1962) Serial position effect (laboratory experiment):  Murdock argued that no matter how many words a person is shown and then asked to recall, items at the beginning  of the list are recalled to a greater degree than those in the middle, while words at the end have a greater recall than either the beginning or the middle. Words recalled at the beginnig are rfered to as the primacy effect, words remembered at the end of the list are refered to as the recency effect.  Evaluation: This supports the MSM because the fact that participants remember words more at the beginning of the list is due to the fact that these words are rehearsed and are starting to pass into the LTM (as suggested by the MSM). Words in the middle of the list are not remembered as well due to the fact that these words are not rehearsed and therefore are lot through displacement. Finally, as suggested by the MSM, the words at the end are remembered well due to the fact that we can hold words in in our STM without rehearsal for up to 30 seconds.

Weaknesses:

(3) Point: Case studies of brain damaged patients criticise the MSM. Evidence: The case of KF demonstrated that his deficit in STM was for verbal information and that the STM for visual material was normal. Evaluation: This is a weakness because it demonstrated that it is possible to damage only part of the STM going against the MSM idea that STM is unitary (suggesting that there may be more than one type of STM).

Click here to learn about the Working Memory Model as developed by Baddeley and Hitch.