1. OUTLINE AND EVALUATE THE MSM
The multi-store model of memory, proposed by Atkinson and Shiffrin suggests information
moves up the system through a variety of stores such as the sensory register, short-term
memory and the long-term memory which are all separate unitary stores.
The sensory register is where information from the environment enters the model from the five
senses, this can be split into iconic and echoic. Within this, the duration is extremely short and
the capacity is extremely large. Moreover, the short-term memory is the second store where we
store immediate events. The duration is short unless rehearsed and has a limited capacity (7
+/-2) and codes acoustically. Finally, the long-term memory is the final and permanent store
within the model. With maintenance rehearsal, information is moved here, meaning duration can
last 2 days to forever and codes semantically.
One strength of the multi-store model of memory is the use of case studies, such as the case
study of HM. HM is a well-known case study in memory. He received an operation, during which
his hippocampus was removed, in order to cure his severe epilepsy. However, when he awoke,
HM could no longer create any long-term memories, meaning his memory would only last for the
duration of STM. This case study shows that STM and LTM are separate unitary stores, as
suggested by the MSM of memory. Therefore a strength of the MSM is that there is case study
evidence to support the model.
However case studies are an idiographic method, meaning they only focus on the individual,
and cannot be generalised to the wider population. As HM had his hippocampus removed to
address seizures, it is impossible to know whether the same things would happen in other
individuals, as it is unethical to replicate this experiment,meaning there is a lack of reliability.
Another strength of the multi-store model of memory is the serial position effect. In an
experiment, participants were read a list of twenty words and were asked to recall them from
memory. It was found that people remember words at the beginning of the list – primacy effect –
this occurs because individuals are able to rehearse these words and transfer them to LTM.
People also remember words at the end of the list – recency effect – these words have not yet
been lost from STM. This provides evidence for MSM as supports how information moves from
Sensory Register to STM and to LTM.
One limitation of the multi-store model of memory would be that the model is too simplistic.
The MSM defines STM and LTM as ‘unitary’ single stores. However alternative models suggest
that both STM and LTM are actually divided into multiple qualitatively different stores. Therefore
the MSM may not be able to fully explain the division within both STM and LTM, meaning that it
is a limited explanation of memory.
Furthermore, a second limitation of the multi-store model of memory is the difference between
elaborative vs maintenance rehearsal. There may be more than one type of rehearsal for LTM.
Craik and Watkins (1973) found that for information to transfer to LTM, the type of rehearsal is
important.Maintenance rehearsal is given in the MSM – this type of rehearsal just keeps
information in STM. Elaborative rehearsal is not described in MSM – this type of rehearsal is
needed for long-term storage i.e. to transfer information to LTM. In this type of rehearsal, we add
meaning to something – link it to other information that you already have etc.
, 2. OUTLINE AND EVALUATE THE DIFFERENT TYPES OF LTM
The Long term memory is the permanent memory store which has an unlimited capacity and
duration and information is coded semantically. Tulving proposed that they are 3 types of long
term memory stores which store different types of information. These memory stores are:
episodic memory, semantic memory and procedural memory.
One strength of the different types of LTM is brain scans. Scientific evidence from brain scans
supports the idea that there are separate types of LTM, with participants recalling different types
of information demonstrating brain activity in different areas. This is a strength as it provides
objective evidence that different stores activate different types of long-term memories.
A second strength of the different types of LTM is evidence from case studies. Case studies
such as Clive Wearing demonstrated that despite damage to the brain, there was damage to the
memory, causing a lack of semantic and episodic memory. However, his procedural memory
was still intact, as he could still play the piano. This is a strength because it shows it is possible
to maintain different types of LTM whilst not having others.
One weakness of the different types of LTM is research generalisation. Research has been
conducted on individual patients, such as Clive Wearing and HM which are fundamentally
isolated. It would be inappropriate to assume that everyone’s LTM is formed in the same way
based upon these case studies.
A strength of identifying different LTM stores has a real life application. Belleville et al. found that
episodic memories can be improved in older people with cognitive impairments. Psychologists
can target certain kinds of memories in order to improve people’s lives. This highlights a benefit
in distinguishing between types of LTM as it can lead to the development of outstanding
treatments.
A limitation is there may only be two types of LTM. Cohen and Squire argued that semantic and
episodic memories are stored in one LTM store called declarative memory (that can be
consciously recalled). Like Tulving, they still agreed that procedural memory was distinct and
called it non-declarative memory. It is important to get the distinctions between these memories
right as it influences memory studies and has a knock on effect on how we use it.