Atkinson and Shiffrin's (1968) Multi-Store model of memory was extremely successful in terms of the amount of research it generated. However, it became apparent that there were a number of problems with their ideas concerning the characteristics of short-term memory. Baddeley and Hitch (1974) developed an alternative model of short-term memory which they called working memory.
- Baddeley and Hitch (1974) argue that the multi-store model is too simplistic.
- Working memory is STM. Instead of all information going into one single store, there are different systems for different types of information. Working memory consists of a central executive which controls and co-ordinates the operation of two subsystems: the phonological loop and the visuo-spatial sketchpad.
- Central Executive: Drives the whole system and allocates data to the subsystems. Deals with cognitive tasks such as mental arithmetic and problem solving.
- Visuo-Spatial Sketchpad: Stores and processes information in a visual or spatial form. Used for navigation.
- Phonological loop: Deals with spoken and written material. It consists of two parts: the phonological store - linked to speech perception + holds information in a speech based form for 1-2 seconds, and the articulatory control process - linked to speech production and is used to rehearse + store verbal information from the phonological store.
The working memory model makes the following two predictions:
- If two tasks make use of the same component of working memory, they cannot be performed successfully together.
- If two tasks make use of different components, it should be possible to perform them as well together as separately.
Research Study: Baddeley and Hitch (1976)
Aim: To investigate if participants can use different parts of working memory at the same time.
Method: Conducted an experiment in which participants were asked two perform two tasks at the same time - a digit span task which required them to repeat a list of numbers, and a verbal reasoning task which required them to answer true or false questions.
Results: As the number of digits increased in the digit span task, participants took longer to answer the reasoning questions, but not much longer. They didn't make any more errors in the verbal reasoning task as the number of digits increased.
Conclusion: The verbal reasoning task made us of the central executive and the digit span made use of the phonological loop.
The 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 sketchpad and phonological loop) and relates them to the long-term memory.
- The central executive…