Baddley et al. did some research into this. They found that participants who were asked to
remember shorter words were more likely to remember them than those who were asked to
remember longer words. This is evidence for the phonological loop.
The phonological loop appears to hold only the words you can say in 2 seconds. Longer words are
harder to remember. This is called the word-length effect, which disappears once an articulatory
suppression task is introduced.
Visuo-spatial Sketchpad.
Baddeley et al. demonstrated the existence of this by giving the subjects a visual tracking task. They
were asked to follow the moving light with a pointer whilst doing one of two tasks. Task 1: Describe all
the angles on the letter F. Task 2: Perform a verbal task. Task one was very difficult while task two was
not, presumably because task 2 involved two different components.
The visuo-spatial sketch pad deals with visual and spatial information. Visual information
refers to what things look like. It is likely that the visuo-spatial sketch pad plays an important role in
helping us keep track of where we are in relation to other objects as we move through our
environment
Episodic Buffer
Baddeley et al. found that when subjects were asked to memorise a list of words and give
immediate recall, their performance was much better for sentences (related words) than single
words (non-related works). THis supports the idea that immediate memory store for items that are
neither visual nor phonological and that draw on long term memory (to link related words).
The episodic buffer acts as a 'backup' store which communicates with both long term memory and
the components of working memory.
Central Executive
The central executive is the most important component of the model, although little is known about
how it functions. It is responsible for monitoring and coordinating the operation of the slave systems
(i.e. visuo-spatial sketch pad and phonological loop) and relates them to long term memory (LTM).
The central executive decides which information is attended to and which parts of the working
memory to send that information to be dealt with.
Bunge et al. used fMRI to see which parts of the brain were most active when the subjects were dual
tasking. They asked them to read a sentence and recall the last word of that sentence. The same
areas were active in both dual and single tasks, but there was significantly more activity while the
subjects were dual tasking indicating that increased attention required increased brain activity.