EDUCATIONAL PSYCHOLOGY

Chapter 2, page 34

Problem 2.1 Understanding Students’ Thinking: Expanding Memory

Capacity

Chase and Ericsson (1981) studied a college student who was able to expand

his digit span from 7 digits to over 80 digits after about 250 hours of practice in

the laboratory over two years. How did he accomplish this?

Response: The student was a runner who had a very rich knowledge base of

running times (his own and those of famous runners) that he used to chunk the

digits. For instance, he might chunk 3-4-7 as a record mile time by Sebastian

Coe and 3-4-9 as a record mile time by John Walker. A series of 3-4-7-3-4-9

could then be combined into a higher chunk (Recent World Records in the

mile). So the memory feat was accomplished by chunking.

Components of working memory. Cognitive psychologists have found evidence that working
memory contains at least three different subcomponents: the phonological loop system, the visuospatial
sketchpad, and the central executive (see Figure 2.4) (A. Baddeley, 2003; A. D. Baddeley, 1996; Holmes
& Adams, 2006). The phonological loop system is a system for retaining auditory information. For
example, when you say a phone number to yourself over and over, you are using the phonological loop
system, because the numbers you are saying are in an auditory format. Evidence suggests that when
people are asked to remember lists of words, they often subvocalize (i.e., they say the word silently to
oneself), so that they are using their phonological loop system.

Figure 2.4 The working memory system includes a phonological loop system, a visuospatial
sketchpad, and the central executive.

The visuospatial sketchpad is the working memory system for storing visual information and for
carrying out operations that involve visual imagery. For instance, if you mentally rotate the figure shown
at the left of Figure 2.5 to determine whether it matches the figure at the right, you will use your
visuospatial sketchpad. Similarly, when you examine a diagram in a textbook, such as a diagram showing
how hydraulic brakes work or how a curveball spins, you employ your visuospatial sketchpad.

phono-

logical

loop

system

visuo-

spatial

sketch-

pad

central

executive