Strengths of the Working Memory Model: Case Studies

We’ve now seen the four components of the working memory model…

The phonological loop is a store for auditory and verbal information…

The visuospatial sketchpad is a store for visual information…

The episodic buffer is a multi-modal store that combines information across senses to create a memory of an event.

And the central executive is a system that manages the three working memory stores and divides our attention across the stores!

So, now that we’ve looked at the working memory model, we can look at the evidence supporting  the model.

And we’re going to look at evidence from three sources: case studies, laboratory experiments, and imaging studies…

And first up, we’re going to look at patient case studies…

For instance, earlier we looked at a patient KF, who had…

Patient KF had damage to his short-term memory, but not his long-term memory.

And his short-term memory damage affected his ability to retain verbal information, but not visual information.

Now, we also saw earlier that the multi-store model can’t explain how patient KF has damage to just his short-term memory…

According to the multi-store model, information must go through the short-term memory store before it is transferred to the long-term memory store…

And there is just one short-term memory store….

So, if this store is damaged, there’s no way for information to reach the long-term memory store!

On the other hand, the working memory model says that we have multiple short-term memory stores, called the…

The three memory stores in the working memory model are the phonological loop, the visuospatial sketchpad and the episodic buffer.

Now, if one of the stores is damaged, such as the phonological loop, [show store crossed out], information can’t pass from this store to long-term memory….

But, information can still be transferred to long-term memory using one of the remaining stores! 

So, the working memory model predicts that people can damage their short-term memory without damaging their long-term memory…

…so long as they haven’t damaged all of their working memory stores!

So, now, how would the working memory model explain patient KF’s symptoms?

According to the working memory model, patient KF had damage to his phonological loop, but not his visuospatial sketchpad, or episodic buffer.

This meant that he struggled to retain sounds and verbal information, but he could still retain other kinds of information in working memory.

And, with the help of his visuospatial sketchpad and episodic buffer, he could still transfer this information into long-term memory.

So, one strength of the working memory model is that it receives support from case studies, like patient KF.

But we’ve also seen that patient case studies have their own limitations…

First, case studies only look at a small number of rare cases.

So, the results might not generalise to other people: we can’t be sure that everyone’s memory works the same way!…

And a second limitation of patient case studies is that it’s hard to establish a cause and effect relationship between the patient’s brain damage, and their behaviour, because we don’t know how the patient behaved before the brain damage! 

Luckily, the working memory model is also supported by other types of research, which we’ll see in more detail next.

But first, to recap…

Case studies of patients like patient KF support the working memory model, because these studies suggest there are multiple short-term memory stores.