Multi-Store Model of Memory

Paper 1 Introductory Topics in Psychology

MemoryDescription, AO1:

 

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.

Expalanations of Memory

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

1) Multi-Store Model of Memory

2) Working Memory Model

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 to the seperate memory stores:
 

Table to show the differences in coding, capacity and duration between SR, STM and LTM

 

Sensory register

Short-term memory

Long-term memory

 

Key research

 

Key research

 

Key research

Coding

Deals with information from the 5 senses:

Haptic, Echoic, Iconic, Olfactory,

Gustatory

Crowder (1993) found that the SR had different durations for each information type – indicating different processing all types

Acoustic

Baddeley gave participants 2 lists of words to remember for immediate recall.

List 1 = acoustically similar, List 2 = acoustically dissimilar.

Increased errors were made in List 1

Semantic

Baddeley gave participants 2 lists of words to remember for immediate recall.

List 1 = semantically similar, List 2 = semantically dissimilar.

Increased errors were made in List 1

Capacity

Very large

Sperling (1960)

Flashed a 3×4 grid of letters for 1/20th /s and asked for recall of one row. Recall was high, which suggests all the information was originally there.

5-9 items

Jacobs (1887) gave participants increasingly long number lists for immediate recall. Jacobs found that the capacity ranged between 5-9

Unlimited

Anokhin (1973) estimated the number of neuronal connections in the human brain as 1 followed by 10.5 kilometres of noughts.

Duration

Limited

Triesman (1964) played identical auditory messages to both ears, with a slight delay between presentations. Ps noticed they were identical if the delay was 2s or less.

Seconds

Peterson & Peterson (1959) read nonsense trigrams to participants (e.g. ZFB) & asked them to count backwards in 3s from a large 3-digit number (to prevent rehearsal). After a specific length of time the participants were required to recall the trigram; 90% recall after 3s, 5% recall after 18s

Lifetime

Bahrick et al (1975) showed participants aged between 17-47 a set of photos and a list of names, some of which were ex-school friends. Those who had left school within 15 years had 90% recall for faces & names, those who left within 48 years had 80% recall for faces & 70% recall for names.

The sensory store is constantly receiving information from the environment. Most of this information receives no attention and so is lost through decay. 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.

 

AO3: Evaluation of The Multi-Store Model of Memory: Atkinson and Shiffrin (1968)

Strengths

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.


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. 


Weaknesses

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)