The working memory model (Baddeley and Hitch 1974) replaced the idea of a unitary STM, it suggests a system involving active processing and short term storage of information.
The working memory model consists of four components which each have a different job. The Central executive (CE) is the key component and can be described as attention. It has a limited capacity and controls two ‘slave’ systems that also have limited capacity. The function of the CE is to direct attention to particular tasks, determining how the brain's ‘resources’ are used for the task. The ‘resources’ are the three ‘slave’ systems. Data arrives from the senses or from the long term memory. Because the CE has a very limited capacity it can’t attend to too many things at once and has no capacity for storing data. The next component is the Phonological loop (PL) which is one of the ‘slave’ systems. This deals with auditory information and preserves the order of information. Baddeley (1986) further subdivided this loop into:

- The phonological store which holds the words you hear, like and inner ear.
- An articulatory process which is used for words that are heard or seen. These words are silently repeated like an inner voice. This is a form of maintenance rehearsal.

The next component is the episodic buffer which is another ‘slave’ system. Baddeley (2000) added the episodic buffer because he realised the model needed a general store. The Phonological loop and Visuo-Spatial Sketchpad deal with processing and temporary storage of specific kinds of information and the central executive has no storage capacity so there was nowhere to hold information that relates to both visual and acoustic information. The episodic buffer is an extra storage system that has limited capacity. The episodic buffer integrates information from the central executive, the phonological loop and the Visuo-Spatial Sketchpad and sends information to the LTM.

The last component and ‘slave’ system is the Visuo-Spatial Sketchpad is used when you have to plan a spatial task (E.g. going home). Visual and spatial information is temporarily stored here. Visual information is what things look like. Spatial information is the physical relationship between things. It has been suggested that the Visuo-spatial sketchpad can be divided into:

- A Visual cache which stores information about visual items e.g colour.
- An inner scribe which deals with spatial relations which stores the arrangement of objects in the visual field.

The working memory is supported by dual task studies. It is easier to do two tasks at the same time if they use different processing systems (verbal and visual) than if they use the same ‘slave’ system.

The KF Case Study also supports the Working Memory Model. KF suffered brain damage from a motorcycle accident that damaged his short term memory. KF's impairment was mainly for verbal information so his memory for visual information was not affected. This shows that there are separate short term memory components for visual information (Visuo-Spatial sketchpad) and verbal information (phonological loop). However using key evidence from case studies where the patient has suffered from serious brain damage have issues as the process of the brain injury is very traumatic which may itself change behaviour so that a person performs worse on certain tasks.

Another research to support this is Paulesu (1993). He carried out a study to investigate the nature of the phonological loop in the working memory model. Participants were required to remember a series of letters or remember the sounds of the letters. Their blood flow in their brain was then monitored using a technique called positron emission tomography. The two tasks gave quite different patterns of blood flow in the brain. The rehearsal of letter ‘sounds were associated with the increased blood flow in Broca’s area of the brain, whereas the letter memory task was associated with a different area of the brain, This provides support for the working memory model because it shows that the phonological loop has two different components which is one for storage and one for rehearsal.

Another limitation is that there are some concerns about the central executive. Some psychologists feel that this is too vague and doesn’t really explain anything. Critics also feel that the notion of a single central executive is wrong and that there are probably several other components.