DIVIDED ATTENTION
DIVIDED ATTENTION
 Duncan (1993) asked participants to make judgments about single
object. They could make two simultaneous judgments about this object
–what it was, as well as where it was located- without any loss
accuracy. However, they made many errors when asked to make two
simultaneous judgments about two different objects, for example where
both objects were located. In other words, our perceptual system can
handle some divided-attention tasks, but we fail when the tasks
become to demanding.
DIVIDED ATTENTION
 Mark Reinitz and his colleagues (1994) asked their research participants to
look at skrtches of faces, with dots across each face. People in the fullattention condition received no instruction about the dots, whereas people in
the divided-attention condition were instructed to count the dots. Later,
everyone was asked to judge whether each face in a series was old or new.
The result was shown in the table below:
Test condition
Old Faces
Conjunction Faces
Full attention
0,81
0,48
Study condition
Divided attention
0,48
0,42
 When our attention is divided, we often fail to perceive stimuli accurately.
DIVIDED ATTENTION
 The research on practice and divided attention confirms the wisdom
of “practice makes perfect”. For example, in two classic studies,
college students were trained to read stories silently at the same
time that they copied down irrelevant words dictated by the
experimenter (Hirst et al., 1980; Spelke et al., 1976). At first, the
students had trouble combining the two tasks; however, after six
weeks of training, they could read as quickly while taking dictation
as when they were only reading. Still, even at this well-practiced
stage, the students were not really attending to the dictated words.
In fact, they were able to recall only 35 of the several thousand
words they had written down. However, with more extensive
training, they became so accomplished at this divided-attention task
that they could even categorize the dictated word without any
decline in their reading rate.
 As Hirst (1986) argues, practice apparently alters the limits of
attentional capacity. Humans do not seem have a built-in, fixed limit
to the number of task they can perform simultaneously (Allport,
1989).