Cognition: Memory, Attention, and Learning - Foundations for Designing User-Centered Systems - page 123

Fig. 5.1 The Serial Position
curve. The primacy effect is
that earlier items are better
remembered and the recency
effect is that items more
recently encountered are
better remembered

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you see with less strong long-term memories. The number of items held in long-
term memory that can be worked with at once is working memory, which we cover
next.

5.2.1.3 Working Memory

Working memory is considered a more dynamic concept than STM. It is
hypothesized as a temporary memory store (an audio or semantic scratchpad) with
associated mechanisms for rehearsing, refreshing, and using the stored informa-
tion. It also includes a mechanism of central or executive attention that regulates
the contents of that memory store based on performing a task. This view is based
on the models and definitions of Baddeley ( 1976 , 1986 ). Working memory is seen
less as a scratch pad than short-term memory, but it is viewed more within the
context of the processing that will use it, and how the scratch pad and processing
interact. This view of working memory suggests that increases in working memory
can have numerous effects, ranging from more directed attention to better per-
formance in general (Engle 2002 ).
These items in working memory are often rehearsed in what is called a pho-
nological loop, where the material to be stored is repeated rapidly to oneself. This
loop can hold about 2 s of verbal information. The direct implications are that
items that are faster to pronounce take up less space. This has been found for
numbers in different languages—languages with long names (in syllables) for
numbers lead to fewer objects that can be retrieved. ''Seven,'' which is two syl-
lables long, for example, will take up more space than ''one.'' Running through
this loop only holds information; it does not alone increase memory for the items.
Working memory for a task is influenced by several factors. Focusing on a
single task directly improves the amount of working memory available for that
task. There also appear to be individual differences in working memory, with some
people having more working memory than others (Daneman and Carpenter 1980 ;
Lovett et al. 2000 ). Talking while doing a task provides some additional memory
(not more traditional working memory, but more memory through the acoustical
loop, which is repeating information verbally to yourself and hearing it, tempo-
rarily increasing your effective working memory), and in addition to slowing down
performance can lead to more insights (Ericsson and Simon 1993 ). Further work
suggests that extreme amounts of practice can lead to a type of increase in working
memory (Ericsson and Kintsch 1995 ).