Selective Attention • 87unattended ear. For example, as the participants were shadowing “They were throwing
stones at the bank,” either the word “river” or the word “money” was being presented
to the unattended ear.
After hearing a number of the ambiguous sentences, participants were presented
with pairs of sentences such as the following:- They threw stones toward the side of the river yesterday.
- They threw stones at the savings and loan association yesterday.
When they indicated which of these two sentences was closest in meaning to one of
the sentences they had heard previously, MacKay found that the meaning of the biasing
word affected the participants’ choice. For example, if the biasing word was “money,”
participants were more likely to pick the second sentence. This occurred even though
participants reported that they were unaware of the biasing words that had been pre-
sented to the unattended ear.
Because the meaning of the unattended word (“money”) was affecting the partici-
pant’s judgment, this word must have been processed to the level of meaning. Results
such as this led McKay and other theorists to propose late selection models of atten-
tion, which proposed that most of the incoming information is processed to the level
of meaning before the message to be processed is selected (Deutsch & Deutsch, 1963;
Norman, 1968).
The selective attention research we have been describing centered around when
selective attention occurs (early or late) and what types of information are used for the
selection (physical characteristics or meaning). But as research in selective attention
has progressed, researchers have realized that there is no one answer to what had been
called the “early-late” controversy. Early selection can be demonstrated under some
conditions and later selection under others, depending on the observer’s task and the
type of stimuli presented. Thus, researchers began focusing instead on simply under-
standing the many different factors that control attention. Two of these factors are
cognitive resources and cognitive load.COGNITIVE RESOURCES, COGNITIVE LOAD,
AND TASK-IRRELEVANT STIMULI
Cognitive resources refers to the idea that a person has a certain
cognitive capacity, which can be used for carrying out vari-
ous tasks. Cognitive load is the amount of a person’s cognitive
resources needed to carry out a particular cognitive task. Some
tasks, especially easy, well-practiced ones, have low cognitive
loads; these low-load tasks use up only a small amount of the
person’s cognitive resources. Other tasks, those that are diffi -
cult and perhaps not as well practiced, are high-load tasks and
use more of a person’s cognitive resources.
One thing that has been studied about cognitive resources
and cognitive load is the relation between (1) the amount of a
person’s cognitive resources that are used by a primary task or
stimulus and (2) how this affects the person’s ability to avoid
attending to other, task-irrelevant, stimuli. Nilli Lavie (1995,
2005) has proposed that the amount of cognitive resources that
remain as a person is carrying out a primary task determines
how well the person can avoid attending to task- irrelevant
stimuli.
This idea is illustrated in ● Figure 4.7. The circle in this
fi gure represents a person’s total cognitive resources, and the
shading represents the portion that is used up by a primary
task. In Figure 4.7a, only part of the person’s resources are
being used by a low-load primary task, leaving resources● FIGURE 4.7 The rationale for the idea that (a) low-load
tasks that use few cognitive resources may leave resources
available for processing task-irrelevant stimuli, whereas (b)
high-load tasks that use all of a person’s cognitive resources
don’t leave any resources to process task-irrelevant stimuli.
Resources used by
low-load primary task
Resources used by
high-load primary taskRemaining cognitive
resourcesNo cognitive
resources remain(a) (b)
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