Overt Attention: Attending by Moving Our Eyes • 99DEMONSTRATION Looking for a Face in the Crowd
Your task in this demonstration is to fi nd Bob Dylan’s face in the crowd pictured in ● Figure 4.22.
Time yourself to see how rapidly you can accomplish this task.You may have located Dylan’s face right away if you just happened to look right
at him, but it is more likely that it took a while, because it was necessary to move your
eyes from face to face to see each one clearly. This shifting of the eyes can be measured
using a device called an eye tracker, which creates records like the one in ● Figure 4.23.
This example shows a person’s eye movements when looking at a picture of a fountain.
The small dots indicate fi xations, places where the eyes briefl y paused, and the lines
indicate saccadic eye movements—movements of the eye from one fi xation to the next.
Typically, people make about three fi xations per second when viewing an unfamil-
iar scene. Eye movement records like this one indicate the parts of the scene that are
attracting the person’s attention.
We will now consider two factors that determine how people shift their attention
by moving their eyes: bottom-up, based primarily on physical characteristics of the
stimulus; and top-down, based on the relation between the observer and the scene—
what the person knows about the scene and the demands of a task that involves objects
in the scene.● FIGURE 4.22 Find Bob Dylan’s face in this group.Michael Ochs Archives/Getty ImagesCopyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.