In this blog, I am summarizing the key points from the chapter on Working Memory from the Handbook of Applied Cognition.
So, what is working memory?
- Working memory plays an important role in human cognition and refers to the ability to actively maintain information in order to accomplish a task.
- The concept of working memory was first introduced by Baddeley and Hitch in 1974 (See Figure above). Their model of working memory consists of a central executive and two slave systems: the phonological loop, which maintains verbal information, and the visuospatial sketchpad, which maintains visual information. The slave systems have limited capacity and the content stored there decays without rehearsal. The central executive can be viewed as an entity that supervises the functioning of the slave systems and activities such as task-switching and multi-tasking is possible because of it.
- Other theoretical models of working memory also exist.
Is working memory capacity limited?
- The answer is ‘yes’.
- In 1956, George Miller proposed the ‘magic number’ of 7 plus or minus 2, according to which humans can keep track of 5 to 9 pieces of information.
- More recent work by Cowan has shown that working memory capacity is even more limited and that humans can attend to only 4 pieces of information at once.
Overload of working memory is responsible for performance failures. There are also individual differences in working memory capacity. This begs the question as to whether working memory be improved and the answer is ‘yes’. Extensive training within a domain, use of strategies (e.g., rehearsal, imagery), attention process training, and repeated practice on executive tasks can be employed to improve working memory capacity.
Working memory demands on an operator can be reduced through design by:
- Helping users integrate multiple pieces of information
- Reducing the amount of irrelevant information presented
- Reducing the amount of information that needs to be mentally transformed
Photo credit: Kurzon, traced by User: Stannered, via Wikimedia Commons.