Working Memory Model
Baddely and Hitch believed that the STM store in the Multistore Model was too simplistic: they thought that short term memory was not a passive store, but several active processes that manipulate information.
Working Memory Components
The central executive is considered the most important part of working memory, because it controls attention and coordinates the actions of the other components, it can briefly store information, but has a limited capacity. The central executive is modality free, which means that it can store information in any sense modality.
The phonological loop consists of two parts, the articulatory control system and the phonological store:
Articulatory Control System (The Inner Voice) The articulatory control system rehearses information verbally and has a time based capacity of about 2 seconds. It is helpful to think of it as the system that you use to mentally rehearse information by repeating it over and over again.
Phonological Store (The Inner Ear – but not to be confused with the canals in your actual ear) The phonological store uses a sound based code to store information, but this information decays after about 2 seconds, unless it is rehearsed by the articulatory control system. The phonological store receives its input either directly from the ears or from long term memory. If you imagine your favourite piece of music you are using your phonological store.
The visuospatial sketchpad stores and manipulates visual information, input is from the eyes or long term memory. if you imagine an object and then picture it rotating you are using your visuospatial sketchpad.
The episodic buffer is a fairly recent addition to the working memory model (Baddeley, 2000). it its purpose is to bind together all of the information from the other components of working memory with information about time and order. This prepares memories for storage in episodic long term memory.
Evaluation of Working Memory
The working memory model is high in face validity, this means that the model seems plausible. In this case, it seems plausible because it fits with everyday experience of manipulating information when solving problems, with short term memory as a dynamic process rather than a static store. For example, Baddeley (1997) suggests that mentally counting the number of windows in your house (or flat) demonstrates the operations of working memory. Normally a person will imagine each room in turn, forming a mental image of each window (Visuospatial sketchpad), they will count using the phonological loop to rehearse the numbers and this will all be coordinated by the Central Executive.
Another advantage of the Working Memory model is that verbal rehearsal is not necessary for all types of information – just verbal strings - this fits better with our everyday experience. For example, we do not have to rehearse everything that happens to us because events are processed by the episodic buffer.
Baddeley (1975) found that participants' memory span for visually presented one-syllable words was greater than for polysyllabic words (words with more than one syllable). This suggests that the articulatory loop is only