Welcome to psych boost, in this video we are going to discuss another model of memory
called the working model of memory. Its effectively an improved version of what we called
the short term memory store in the multi-store model video, in that video we said that model
was a little too simplistic, with the working memory model we will be able to explain how our
brain is able to hold and work on both auditory and visual information in short term memory.
So the working memory model, now if you started a-level psychology with the memory
unit these models of memory can seem a little complex for new a-level students,
but I would say if you learn to draw them out from memory
that can really help you remember how they work and remind you of the studies that support them.
So hopefully you can draw out the multi-store model of memory from memory, it looks
like this. In our discussion of the multi-store model we covered the short term memory store.
Well researchers Baddeley and Hitch had some criticisms of the short term memory store.
Firstly that that short term memory clearly isn't unitary, it's not just one single process, it’s
not just a stopping off station for information between the sensory register and long term memory.
Also they thought rather than a passive store just holding on to information and
passing it on to long term memory, we use short term memory to process, or work on and combine
multiple types of information, so we would describe working memory as an active processor.
So those are two differences between the short term memory store in the multi-store model
and the working memory model. #The working memory model
You can see here all the parts of the working memory model,
again you need to be able reproduce this model from memory. And describe each of the components,
The first component is the central executive,
this is the part of the model that pays attention to information from the senses. It’s known as the
head of the model because it passes information on to and controls other components that are called
“sub-systems'. The visio-spatial sketchpad, the phonological loop and the episodic buffer.
The central executive is very limited in how much information it can hold at any one time,
and can only hold one type of information at a time, but can
switch quickly between each type of information. The phonological loop is one of the subsystems,
and is controlled by the central executive. It processes auditory information like sounds and
words. We can break the phonological loop into two sections: the phonological store that we
can think of as the inner ear, holding on to the words that you hear, and the articulatory process,
your inner voice that you use for maintenance rehearsal. And when considering capacity we would
say the phonological loop has a capacity of how much you can say in two seconds.
The visuio-spatal sketchpad is another of the slave systems, as the name suggests
its responsible for processing visual and spatial information, it can be described as an
inner eye. again we can say it's controlled by the central executive. A researcher called
Logie suggests the vss can be broken down into two processes, a visual cache that is a
passive store for forms and colour and the inner scribe which is an active store holding on to the
relationships between objects in 3D space. Finally we can describe the final part of
the model, the episodic buffer. This was added to the model by Baddeley in 2000, in response
to criticism of the model that it couldn't fully explain how information was effectively
combined from both visual, acoustic and long term memory stores. So the episodic buffer is where
information is integrated and stored. And that is the working memory model
Now just something quick to point out, AQA has written something a little different between
what we need to know for the multi-store and working memory models. For the multistore model
of memory it says features of each store: coding, capacity and duration. So we had to go into
serious depth for each store so we could describe and evaluate each store on each of those factors.
Fortunately for the working memory model the specification only says the features of the model:
coding and capacity, so if we get a question about coding or capacity we can use information
and evidence from any component of the working memory model to answer that question.
As a reminder then we have already said when it comes to coding, the phonological loop is acoustic
and the visuospatial sketchpad is visual, and when talking about capacity the phonological
loop is what can be said in two seconds and the central executive is limited in capacity,
according to a researcher called cowen its 4 items plus or minus 1.
#Evaluating the working memory model We are going to consider four studies of the
working memory model, a dual task performance study that shows the separation between the
slave systems, a case study that supports that finding, biological evidence for the existence
of the episodic buffer and evidence for the capacity of the phonological loop.
To help us understand dual task studies, Have you ever thought about how you can focus on
drawing and talking to someone at the same time, but find it really difficult to focus on reading
if someone is talking to you at the same time? In the first example the central executive can help
us perform both tasks by sending the visual information to the visuo-spatal sketchpad,
and the verbal information to the phonological loop. But in the second example the phonological
loop is overwhelmed because too much of the same type of information is pushed to it.
Let's start our evaluations then with a dual task performance study.
Baddely asked participants to perform two tasks, either two visual tasks, tracking moving lights
and describing the angles of the letter F, or performing a visual task and a verbal task,
participants performed much better when both the tasks were different. This suggests that
the visuo-spatial sketchpad exists as a separate process from verbal processing, the phonological
loop, and that the VSS has limited capacity. The separation of the phonological loop and
visuo-spatial sketchpad can also be seen in a case study by Shallice and Warrington,
this is the case study of a man known as KF, his short term memory issues were caused by a brain
injury. But he had selective impairments to his short term memory store. Only his verbal short
term memory was affected, he had no problems with the functioning of his visual short term memory.
This suggests then, the phonological loop and visuo-spatial sketchpad exist
as separate processes, and they are located in different parts of the brain.
We have brain scanning evidence by Prabhakaran that seems to show the physical location of the
episodic buffer in the brain using FMRI. The researchers gave participants tasks that had
them holding equal amounts of verbal and spatial information in short term memory.
In some of the trials the both the visual and spatial information was separated,
but in other trials the visual and verbal information was integrated. Now importantly
the brain scans showed more activation in an area of the brain called the prefrontal cortex when the
information was integrated, and posterior areas of the brain when it was integrated.
This suggests the episodic buffer exists and has an identifiable location in the brain.
A final quick study Baddeley found that people could remember more shorter monosyllabic words
like “bond” and “yield” than longer words like “opportunity”, this is a demonstration
of the world length effect, people can remember about two seconds worth of verbal information,
supporting the capacity of the phonological loop as two seconds.
#Additional Evaluations.
Ok with those evaluations we should be able to provide evidence for the existence of the
components of the working memory model and talk about the capacity. But we do need to cover
some additional evaluations on how we can criticise the working memory model
and some of the research that supports it. Firstly the central executive,
as I’ve explained the working memory model that's the bit that may have seemed the least clearly
defined and Psychologists have argued it isn't a fully operationalised concept. In the working
memory system it seems to act as a homunculus, a little man in the brain performing any function
that isn't fully explained by the model. Baddely accepts this criticism, in fact the addition of
the episodic buffer was to address some of the problems with the central executive such as
how information can be integrated. But baddeley suggests rather than seeing this as a problem,
there are opportunities for future research in explaining the functions of the central executive.
We can positively criticise the working memory model by saying it does seem to be
more accurate in describing our short term memory than the short term memory store,
especially in describing it as an active processor. This has been influential,
psychologists now will often not use the term short term memory but use the term working memory.
Now one criticism we will use a few times in the memory unit is the reliance on laboratory studies,
and while they offer a good control over extraneous variables giving them high internal
validity, we can argue that there are problems applying the findings outside of the experiment,
so there are problems with external validity, the tasks themselves are designed so data can
be collected, that often makes the tasks very different to how we use memory in real life,
they lack what's called mundane realism. This means the findings from memory studies
collected in experimental situations may not be generalisable to how we use memory in real life.
To understand my final evaluation we need to understand the term inference,
cognitive psychologists can’t directly observe the working model of memory, they observe behavior
and make assumptions or inferences about the underlying process that led to that behaviour.
Those inferences are effectively educated guesses, and those guesses could be wrong, when applied
to studies on working memory, researchers have used inferences, there could actually
be a completely different set of processes that underpin memory that produce the same behaviours
meaning the working memory model is incorrect. Ok, I’ve given you a lot to work with there,
mostly because there is a lot that can be asked in questions on the working memory model so I want to
prepare you for every eventually. But if you're feeling a little overwhelmed with all of that,
my advice, as with all my videos is pick the ideas and evaluations you're most comfortable with and
if asked a question, shape that knowledge as best you can to answer the question set.
have a go at this a real exam question on the working memory model. If your a psych boost
patron at the neuron level and above you can access a tutorial on psych boost .com.
in it I will talk you through a model answer for this question and general tips.
for everyone else don't forget to subscribe so you don't miss the videos released right
up to your exams, and I will see you in the next psych boost video, explanations for forgetting.