Exploring Theories of Working Memory

This assignment delves into the multifaceted concept of working memory. It presents a comprehensive overview of prominent theories, models, and ongoing debates within the field. Authors like Baddeley, Hintzman, Jones, and Logie are cited to provide diverse perspectives on working memory capacity, coding strategies, and its relationship to long-term memory and cognitive processes.

Running head: PSYCHOLOGY
“The multi-store model of memory (Atkinson and Shiffrin 1968) offers a complete account of
the workings of human memory”
Name of the Student
Name of the University
Author Note

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Executive summary
This report deals with the concept of Multi-store model (MSM) of memory that has
been suggested by Atkinson and Shiffrin in 1968 along with finding research evidence that
proves that this model accounts for the working of human memory. This report also provides
an alternative model to that of the MSM of memory. MSM of memory mainly highlights that
memory has three stores which are the sensory register, then short-term memory and lastly,
long-term memory. This place processes information just like a computer as input, processing
and output. The research studies of Jacobs 1887, Peterson & Peterson in 1959, Baddeley
1966 as well as Bahrick et al., in 1975 were discussed based on which it can be said that
MSM of memory as proposed by Atkinson and Shiffrin in 1968 provides an outright account
of the operations of human memory. However, an alternative model in contrast to MSM of
memory has also been suggested which is known as Working Memory Model by Baddeley
and Hitch in 1974 which states that the short-term memory has four separate features namely
central executive, then the phonological loop, the visuo-spatial scratch pad and lastly,
episodic buffer.

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Table of Contents
Introduction................................................................................................................................3
Key principles of MSM..............................................................................................................3
Evaluation research studies........................................................................................................6
Alternative model.......................................................................................................................8
Conclusion................................................................................................................................10
References................................................................................................................................12

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Introduction
Memory is the title that has been provided to the structures as well as processes,
which intricate in the storage and future retrieval of information. Information can be of
various forms like images, sounds or meanings. According to the psychologists, the term
memory encloses three necessary aspects of processing information and they are memory
encoding, storage and retrieval (Tonegawa et al. 2015). Encoding information means
information enters the memory system from sensory inputs and then they must be modified in
such a form where the human memory system can cope as well as store it. The next aspect is
of storage of information that for how long information has been stored or what is the
capacity of storage at any time. Lastly, retrieval is taking out the stored information from the
memory. In the aspect of retrieval comes the concept of STM and LTM that is for STM the
information is stored and retrieved consecutively whereas, in LTM it is done by association.
However, in this report the discussion will be mainly on whether MSM of memory proposed
by Atkinson and Shiffrin, 1968 provides an outright description of the operations in a human
memory. Moreover, researches related to this topic will be evaluated along with discussion of
an alternative model of memory.
Key principles of MSM
In 1968, Atkinson and Shiffrin suggested the Multistore model of memory (MSM)
which is further called Modal model. According to the model the important principles are that
memory consists of total three stores, which are the sensory register, the short-term memory
(STM) and the long-term memory (LTM). The information is passed against one store to the
other in a straight manner and defined as the information-processing model just like that of a
computer with a facility of input, processing as well as the output (Ornstein 2014).
Information here is mainly perceived by the senses after which they invade the sensory

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memory. Now if this information gets attention then only it will be invading the short-term
memory (STM). Then, if this piece of information is rehearsed then it will be shifted from
STM to the long-term memory (LTM). Therefore, the information is forgotten if there is lack
of maintenance rehearsal as well as the information may get lost even from the STM by the
process of displacement or decay (Baddeley et al. 2012).
In the memory stores however, each of the stores are uniform structure and have their
own features in names of encoding, the capacity as well as duration.
1. The ways in which information are modified so that in the memory they can be stored
is known as Encoding. Three ways are there through which information can be
encoded and they are-
 Visual
 Acoustic
 Semantic
2. The amount of information one can store is called the Capacity.

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3. The period of time until which the information can be stored inside the memory and
this is known as Duration.
However, there are three basic types of memory and they are as follows-
 Sensory memory- This is where the initial processing of storing the information
that have been collected through the senses are done. As the senses work
constantly thus, here information stays for subtle period and is replaced frequently
by new information (Li, Cowan and Saults 2013).
Duration- ¼ to ½ seconds
Capacity- larger capacity due to experiences from all senses
Encoding- various stores for each sense organs.
 The Short-term or working memory- This is the second stage of MSM where the
information are stored for a very brief period.
Duration- 0-18 seconds
Capacity- 7+/- items
Encoding- mostly auditory
 The Long-term memory- This is the final stage in this model, which is mainly
concerned, for remembering things for longer time or throughout one’s lifespan
(Jeneson and Squire 2012).
Duration- limitless
Capacity- limitless
Encoding- many semantic but mainly visual and auditory.
Thus, the sensory memory, the STM and the LTM are interlinked and mainly work in
coordination so that they can assist the brain in storing information to recall in the future.

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However, this model has certain strengths as it delivers a clear understanding of the structure
as well as the process of the short-term memory. Thus, this model is impactful in generating a
lot of research on memory. However, there are many studies on memory that helps the
differences between the STM and the LTM in accordance with encoding, then duration and
capacity but this MSM model narrates primacy and recency effects as well. Murdock has this
experiment done in 1962 about serial positions where the participants were bestowed with a
list of words and were requested to freely recall them (Hintzman 2016). The outcome
suggested that the words that are in the beginning of the list or the ones that were in the end
were better recalled than the middle ones, which was mostly forgotten. Thus, the words prior
in the list were pushed into LTM thus, primacy effect as they have been rehearsed
acoustically and the words in the end of the list were pushed into STM thus, recency effect.
Evaluation research studies
There are several studies done on memory that provides evidence about the working
of human memory. However, Jacobs did an advance study on the STM capacity in 1887. This
study came up with the analysis of ‘magical number’ 7+/- 2 which is assumed to be the
number of item one can grasp in the STM (Jones and Macken 2015). However, Miller in
1956 tried to explore the reason behind this limitation and came up with the reason that it is
not because of the load of the information but rather in a word, there is more information than
just being a binary figure. However, before Miller, Jacob established this concept when he
presented a group of participants with sequence of numbers and was asked to repeat them in
proper order. The sequences increased gradually from short to long with one digit at a time.
The result that Jacob found was a digit span of 9.3 on an average, but the average was 7.3
items when letters were used. He also found an impact of age difference as digit span
increases all over childhood (Schneider 2015).

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In 1959, Peterson & Peterson in their study explored the duration of STM as well as
provided factual evidences for MSM. They guided an experiment where 24 participants had
been given the task of recalling trigrams (Wang et al. 2015). Trigrams are three consonant
syllables that have no meaning. However, participates were also restricted from rehearsing
what they have learned by making them count backward from any random number. This
technique is known as brown Peterson technique. Therefore, the result was that STM has a
finite duration if rehearsal is blocked which is followed by loss of information from STM.
Moreover, it also displays that if duration is to be considered then STM is divergent from
LTM and therefore, overall supporting the MSM of memory (Warrington 2014).
Baddeley in 1966 investigated the impact of acoustic and semantic coding in STM as
well as LTM. In the first study, which was about STM the participants, were asked instantly
to serially recall from the list of five words that were taken out from a pool of words that
were presented to them. On the other hand, for LTM study each of the lists were increased to
ten and then after providing them with an interval of twenty minutes they were asked to recall
those words. The outcome was that words who sounds similar are much difficult to recall
with the help of STM than those words are sounding different. Along with those words,
which have similar meanings, are also found to have little harmful effect on STM. However,
STM has been found in depending on acoustic coding while LTM on semantic coding (Henry
et al. 2012).
In another study by Bahrick et al. 1975, their chief aim was to analyze the time span
of very long-term memory (VLTM) by testing the duration by examining recall of
information from real life. American high school students were the participants of this study
who are in between the age group 17-74years. Participants has been tested on recall in four
different methods-

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1. Free recall of names of their old classmates as much as feasible
2. Photo recognition test
3. Name recognition test
4. Name and photo matching test
The result finally concluded that classmates are seldom forgotten, however there are
times when cues are needed and that recognition was more desirable than recall (PAMUKCU
and AKBAROV 2015). Therefore, all these above research studies in a way supported the
MSM of memory.
Alternative model
Baddeley & Hitch (1974) - Working memory model (WMM)
In 1974, Baddeley and Hitch came up with the alternative model to that of MSM of
memory and thus, proposed the Working memory model. This model has been created to
straightaway question the notion of one isolated unitary store for the memories in the short-
term. However, this WMM is built on the results of the study of dual task, which further
indicated that it has four different elements of the STM or the working memory (Aben,
Stapert and Blokland 2012). The diagram below outlines the elements of the Working
Memory Model-

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The four main components of this model are described as below-
 Central Executive- This is an essential feature, which is included in problem
solving or decision-making. It also has a major role to play in controlling attention
as well as helps in designing and combining information not from secondary
system but also from the LTM. Therefore, it is very much adaptable in nature and
can summon information from whichever modality in spite of having limited
storage capacity and can attend to few things at one time (Otto et al. 2013).
 Phonological loop- The other part of this WMM, is the Phonological loop which is
capable of storing restricted number of sounds those are speech based for short
periods. It is assumed that it consists of two of the elements, which are the
phonological store as known as inner ear or the articulatory control process also
called inner voice. The one, which permits the acoustically coded items to get
stored for shorter time, is associated with inner ear while the inner voice is

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responsible for sub-vocal repetition of those items that are stored in phonological
store.
 The visuo-spatial scratch pad- This is storing the Visual and the spatial
information, which can be considered as the inner eye (Logie 2014). However,
this is accountable for setting as well as operating mental images. Moreover, just
like the phonological loop, the visuo-spatial scratch pad has restricted capacity but
the limits are independent for both the elements.
 Episodic buffer- In 2000 Baddeley, came up with the added component known as
the episodic buffer. Episodic buffer is mainly accountable for merging and
manipulating materials. However, its capacity is limited and it depends highly on
executive processing. Moreover, it attaches information from various sources into
lumps or episodes therefore the term ‘episode’ are given. Lastly, the important
function of this element is to recall materials from the LTM and merge them into
STM as required by the Working memory.
This model has several strength like there are confirmations through which the
authenticity of phonological loop can be supported like for instance the word length effect of
Baddeley in 1975. Along with evidences that can support visuo-spatial scratch pad like for
instance in 1973, Baddeley’s experiment where participants holder a pointer with a spot of
light that was moving while foreseeing the block letter F.
Conclusion
To conclude this report, it can be said that in 1968, Atkinson and Shiffrin proposed
the Multistore model of the memory, which is also called Modal model. It proposes that the
memory is considered to have three stores, which are sensory register, the STM or the LTM.
This model makes it clear that sensory register, STM as well as LTM all are very much

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linked as sensory memory first registers the information then that information which are
attended few are pushed to the STM from where the ones which are rehearsed moved to the
LTM. According to the research evidences discussed above it is clear that MSM of memory,
which has been proposed in the year 1968 by Atkinson, and Shiffrin provides an outright
account of the operations of human memory. The alternative model to MSM has been
discussed which is the Baddeley and Hitch’s WMM of 1974 which says that STM has four
separate features namely central executive, then phonological loop, then the visuo-spatial
scratch pad and lastly, episodic buffer and is not an isolated unitary store. Therefore, the
strength of MSM is that it clearly outlines the understanding of the structure and the process
of the short-term memory as well as the differences between STM and LTM. Whereas, in the
alternative model of WMM is that it not only explains the storage but also defines the
processing of information in the memory. On the other hand, the weakness of MSM is that
the model is too simple and oversimplifies LTM and STM and for WMM the weakness is
that the concept of central executive is too unclear and needs more explanation.

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References
Aben, B., Stapert, S. and Blokland, A., 2012. About the distinction between working memory
and short-term memory. Frontiers in psychology, 3.
Baddeley, A., Wandell, B.A., Rauschecker, A.M., Yeatman, J.D., Fiske, S.T., Schacter, D.L.,
Taylor, S.E. and Lefkowitz, R., 2012. Working Memory: Theories, Models, and
Controversies. Annual Review of Psychology, 63.
Henry, L.A., Messer, D., Luger-Klein, S. and Crane, L., 2012. Phonological, visual, and
semantic coding strategies and children's short-term picture memory span. The Quarterly
Journal of Experimental Psychology, 65(10), pp.2033-2053.
Hintzman, D.L., 2016. Is memory organized by temporal contiguity?. Memory &
cognition, 44(3), pp.365-375.
Jeneson, A. and Squire, L.R., 2012. Working memory, long-term memory, and medial
temporal lobe function. Learning & Memory, 19(1), pp.15-25.
Jones, G. and Macken, B., 2015. Questioning short-term memory and its measurement: Why
digit span measures long-term associative learning. Cognition, 144, pp.1-13.
Li, D., Cowan, N. and Saults, J.S., 2013. Estimating working memory capacity for lists of
nonverbal sounds. Attention, Perception, & Psychophysics, 75(1), pp.145-160.
Logie, R.H., 2014. Visuo-spatial working memory. Psychology Press.
Ornstein, P.A., 2014. Memory Development in Children (PLE: Memory) (Vol. 20).
Psychology Press.

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Otto, A.R., Raio, C.M., Chiang, A., Phelps, E.A. and Daw, N.D., 2013. Working-memory
capacity protects model-based learning from stress. Proceedings of the National Academy of
Sciences, 110(52), pp.20941-20946.
PAMUKCU, A. and AKBAROV, A., 2015. BİLİŞSEL SÜREÇ VE İKİNCİ DİLDE
KELİME ÖĞRENMENİN ANALİZİ. Erzincan Üniversitesi Sosyal Bilimler Enstitüsü
Dergisi, 9(2), pp.221-232.
Schneider, W., 2015. A brief history of memory development research. In Memory
development from early childhood through emerging adulthood (pp. 9-23). Springer
International Publishing.
Tonegawa, S., Pignatelli, M., Roy, D.S. and Ryan, T.J., 2015. Memory engram storage and
retrieval. Current opinion in neurobiology, 35, pp.101-109.
Wang, T., Ren, X., Li, X. and Schweizer, K., 2015. The modeling of temporary storage and
its effect on fluid intelligence: Evidence from both Brown–Peterson and complex span
tasks. Intelligence, 49, pp.84-93.
Warrington, E.K., 2014. The double dissociation of short-and long-term memory. Human
Memory and Amnesia (PLE: Memory), 4, p.61.