Memory Working memory 

In 1974 Baddeley & Hitch proposed a working memory model which replaced the concept of general short term memory with specific, active components. In this model, working memory consists of 3 basic stores - the central executive, the phonological loop & the visuo-spatial sketchpad. In 2000 this model was expanded with the multimodal episodic buffer.

The central executive essentially acts as attention. It channels information to the 3 component processes - the phonological loop, the visuo-spatial sketchpad, & the episodic buffer.

The phonological loop stores auditory information by silently rehearsing sounds or words in a continuous loop - the articulatory process . Then, a short list of data is easier to remember.

The visuospatial sketchpad stores visual & spatial information. It is engaged when performing spatial tasks or visual ones .

The episodic buffer is dedicated to linking information across domains to form integrated units of visual, spatial, & verbal information & chronological ordering . The episodic buffer is also assumed to have links to long-term memory & semantical meaning.

The working memory model explains many practical observations, such as why it is easier to do 2 different tasks than 2 similar tasks , & the aforementioned word-length effect. However, the concept of a central executive as noted here has been criticised as inadequate & vague.