Cognition: Memory, Attention, and Learning - Foundations for Designing User-Centered Systems - page 134

Fig. 5.4 This picture shows someone (circled) doing more tasks than their system (both vehicle
and head) were designed for—driving in a crowded urban environment and talking on a hand-
held cell phone. The phone in this position takes both verbal and motor attention, and it causes an
additional planning load to operate the car one-handed, and leads to poor situation awareness
(i.e., they did not see the person on the street who took this picture). Also note the Gestalt effect
of the can and tree!
Designing systems to attract, manage, and maintain attention is important.
Figure 5.4 shows a user with a task that requires attention (driving), who is also
attempting to perform an additional task (talking on a cell phone). If you would
like a short demonstration of attention, go to http://www.youtube.com/watch?v=
-AffEV6QlyY , which takes advantage of your ability to pay attention. It takes
some time to understand, and you should not be too easily shocked.
Attention refers to the selective aspects of perception which function so that at
any instant a user focuses on particular features of the environment to the relative
(but not complete) exclusion of others. There are several useful metaphors for
describing attention. It can be seen as a set of buffers that hold information for
processing. It is directly related to that processing as well.
You might imagine attention as the area and process of central cognition, such
as work being done on a table. Tasks that take less attention need less of the table
or less of the time of the person working at the table. Many processes in human
cognition are thus closely tied to the concept of attention as a space for cognition,
and various parts of a processor can support attention.
Figure 5.5 shows two common and important uses of attention. Both situations
involve aspects of motor control and cognition, and require monitoring the situ-
ation and taking corrective action. In both cases performance suffers when the
tasks are not given sufficient attention.
There are also other aspects of human behavior that are not based on focal or
conscious attention. We can still do some information processing without con-
sciously attending to information—how else would we know to shift our attention