108 • CHAPTER 4 Attention
the direction cue, their task was to press a key when they saw
the coherent motion (● Figure 4.37b). If they had seen the other
cue, they were to continue passively observing the display. Brain
activity was measured during and after the cue was presented,
but before the coherent motion.
The orange lines in ● Figure 4.38 indicate that attention to an
expected direction of motion caused brain activity to increase in a
number of brain areas. The green lines indicate brain activity for
the passive condition. The main signifi cance of this result is that
attention increases activity throughout the brain.
Widespread attentional effects have been demonstrated in
many other experiments as well. ● Figure 4.39 shows locations
of areas that Michael Posner and Mary Rothbart (2007) have
identifi ed as being involved in three different types of attentional
processing: (1) Alerting is achieving a high sensitivity to incom-
ing stimuli, like that achieved by air traffi c controllers who must
be continually vigilant. (2) Orienting is focusing attention where
visual targets may appear. This occurs in both overt attention,
when the person shifts attention by making an eye movement, and
covert attention, when attention shifts without eye movements, as
in the precueing task. (3) Executive control of attention occurs
for tasks that involve confl ict, such as the Stroop task or fl anker
compatibility task.
For our purposes, the names of the specifi c brain structures
aren’t important; what is important is that so many different areas
of the brain are involved. However, it is worth noting that execu-
tive functions, which involve resolving confl icts between responses
caused by different stimuli, are served by areas in the frontal lobe,
which is also the site of high-level thinking, such as solving prob-
lems and making decisions.● FIGURE 4.37 (a) Participants in Shulman and coworkers’ (1999) experiment saw either a cue
indicating which direction of a moving dot display they should attend to (the arrow shown here) or
a cue indicating that they should passively observe the moving dot display. (b) After seeing random
dot movement for about a second, participants saw coherent movement in a particular direction.
Participants in the attention condition pressed a key when they saw coherent motion. Participants in the
passive group continued to observe the display.(a) Attend to cued direction. (b) Press key if motion is seen in cued direction.● FIGURE 4.38 The results of Schulman and coworkers’
(1999) experiment, showing some of the brain areas that
were activated by viewing the moving dots. The graphs
indicate the amount of brain activity when participants
were cued to pay attention to a particular direction of
movement (orange lines) and when they were cued to
just passively view the moving dots (green lines).
(Source: From M. Corbetta & G. L. Shulman, “Control of Goal-Directed and
Stimulus Driven Attention in the Brain,” Nature Reviews Neuroscience, 3,
201–215, Figure 2, p. 203, 2002. Reprinted by permission of Macmillan
Publishers Ltd.)Attend direction
PassiveFrontalParietalTemporalMin Max CueCopyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.