Question

4. Explain Baddeley’s Model of Working Memory. What clinical implication can be derived from this model? (4 points)

5. Why does mild damage to executive function cause major problems in functional ability? (2 points)

Answer 1

Baddeley's model argues that working memory is like a multi-part system, and each system is responsible for a different function. Each part is only able to processes so much and the components of this system, according to Baddeley, function more or less independently of one another. The model has four major components that we'll discuss now.

Phonological Loop
The first piece of the model is known as the phonological loop. This is the part of the system that processes spoken language, or information we get from speech. This is also how we process things like arithmetic problems, new vocabulary words, or an address we see written down.

Basically, the phonological loop is all about written and spoken information. The word 'phonology' refers to the branch of linguistics that deals with how words and sounds are organized in language, so that's one way to remember what this component does.

The visuo-spatial sketchpad is responsible for processing visual and spatial information. It can be fed either directly, through perception, or indirectly, through a visual image. The visuo-spatial sketchpad allows people to store images of objects and their locations. The sketchpad is also used in navigation. When a person goes from one location to another, it is the visuo-spatial sketchpad that is stimulated. It is also activated in various activities such as puzzles, mazes, and games. There are two components to the sketchpad. The visual cache stores information pertaining to color and visual form. The inner scribe rehearses information from the visual cache and transfers information from the visual cache to the central executive. The inner scribe also deals with spatial and movement information, and is involved in the planning and execution of body movements.  

The central executive incorporates information from the phonological loop, the visuo-spatial sketchpad, the episodic buffer, and from long-term memory. The complexity of the central executive is not yet fully known. Some of the major functions involved with the central executive are the switching of retrieval plans, time sharing in multitasking, selective attention, suppressing irrelevant information, daydreaming, and temporary activation of long-term memory. These are not all of the functions of the central executive, and it is important to realize that it is not fully clear what the central executive is capable of.

The episodic buffer was not a part of Baddley’s original model. It was added to the model 25 years later. It is seen as a place to temporarily integrate information gathered from the phonological loop, visuo-spatial sketchpad, and long-term memory. The episodic buffer is controlled by the central executive, yet it transfers information into and out of the long term store. The addition of the episodic buffer allowed a clearer connection to be made between working memory and long-term memory.