Cognitive Psychology: Connecting Mind, Research and Everyday Experience, 3rd Edition

Working Memory and the Brain • 137

(thereby providing extra capacity) and is connected to LTM

(thereby making interchange between working memory and

LTM possible). Notice that this model also shows that the

visuospatial sketch pad and phonological loop are linked to

long-term memory.

The proposal of the episodic buffer represents another step

in the evolution of Baddeley’s model, which has been stimulat-

ing research on working memory for more than 30 years since it

was fi rst proposed. If the exact functioning of the episodic buf-

fer seems a little vague, it is because it is a “work in progress.”

Even Baddeley (Baddeley et al., 2009) states that “the concept

of an episodic buffer is still at a very early stage of develop-

ment” (p. 57). The main “take-home message” about the epi-

sodic buffer is that it represents a way of increasing storage

capacity and communicating with LTM.

Although we have been focusing on Baddeley’s model

because of the large amount of research it has generated, his is

not the only model of working memory. For example, a model

proposed by Nelson Cowan (1988, 1999, 2005) has focused on

how working memory is related to attention and suggests that working memory and

attention are essentially the same mechanism. This idea is supported by the fi nding that

the same areas of the brain are activated by attention and by working memory tasks

(Awh & Vogel, 2008).

1. Describe two fi ndings that led Baddeley to begin considering alternatives to the
   modal model.


2. What are the differences between STM and working memory?


3. Describe Baddeley’s three-component model of working memory.


4. Describe the phonological similarity effect, the word length effect, and the
   effect of articulatory suppression. What do these effects indicate about the pho-
   nological loop?


5. Describe the visuospatial sketch pad, the Shepard and Meltzger mental rota-
   tion task, and Brooks’s “F” task. Be sure you understand what each task indi-
   cates about the visuospatial sketch pad.


6. What is the central executive? What happens when executive function is lost
   because of damage to the frontal lobe?


7. What is the episodic buffer? Why was it proposed, and what are its functions?

Working Memory and the Brain

We have seen from previous chapters that cognitive psychologists have a number

of tools at their disposal to determine the connection between cognitive functioning

and the brain. The major methods are (1) analysis of behavior after brain damage,

either animal (Method: Brain Ablation, Chapter 3, page 71) or human (Method:

Dissociations in Neuropsychology, Chapter 3, page 73); (2) recording from sin-

gle neurons in animals (Method: Recording From a Neuron, Chapter 2, page 28);

and (3)  recording electrical signals from the human brain (Method: Event-Related

Potential, Chapter 2, page 34) and measuring activity of the human brain (Method:

Brain Imaging, Chapter 2, page 30).

TEST YOURSELF 5.2

● FIGURE 5.22 Baddeley’s revised working memory

model, which contains the original three components plus

the episodic buff er.

Central

executive

Episodic

buffer

Phonological

loop

Long-term memory

Visuospatial

sketch pad

Copyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.