Cognitive Psychology And Its Implications.
Cognitive Psychology And Its Implications.
Respond in 1000 words with some scholarly references. Use citations, cite your references.
Please read attachment.
What did you find most interesting or “surprising” about chapter 4?
Try answering these two questions:
• How many windows are in your house? • How many nouns are in the American Pledge of Allegiance?
Most people who answer these questions have the same experience. For the first
question they imagine themselves walking around their house and counting windows.
For the second question, if they do not actually say the Pledge of Alliance out loud,
they imagine themselves saying the Pledge of Allegiance. In both cases they are creating
mental images of what they would have perceived had they actually walked around
the house or said the Pledge of Allegiance.
Use of visual imagery is particularly important. As a result of our primate heritage,
a large portion of our brain functions to process visual information. Therefore, we use
these brain structures as much as we can, even in the absence of a visual signal from
the outside world, by creating mental images in our heads. Some of humankind’s most
creative acts involve visual imagery. For instance, Einstein claimed he discovered the
theory of relativity by imagining himself traveling beside a beam of light.
A major debate in this field of research has been the degree to which the processes
behind visual imagery are the same as the perceptual and attentional processes that we
considered in the previous two chapters. Some researchers (e.g., Pylyshyn, 1973, in an
article sarcastically titled “What the mind’s eye tells the mind’s brain”) have argued that
the perceptual experience that we have while doing an activity such as picturing the
windows in our house is an epiphenomenon; that is, it is a mental experience that does
not have any functional role in information processing. The philosopher Daniel Dennett
(1969) also argued that mental images are epiphenomenal—that is, that the perceptual
components of mental images are not really functional in any way:
Consider the Tiger and his Stripes. I can dream, imagine or see a striped tiger, but
must the tiger I experience have a particular number of stripes? If seeing or imagining
is having a mental image, then the image of the tiger must—obeying the rules of
images in general—reveal a definite number of stripes showing, and one should be
able to pin this down with such questions as “more than ten?”, “less than twenty?”
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Verbal Imagery versus Visual Imagery | 93
Dennett’s argument is that if we are actually seeing a tiger in a mental image, we
should be able to count its stripes just like we could if we actually saw a tiger.
Because we cannot count the stripes in a mental image of a tiger, we are not having
a real perceptual experience. This argument is not considered decisive, but it does
illustrate the discomfort some people have with the claim that mental images are
actually perceptual in character.
This chapter will review some of the experimental evidence showing the ways that
mental imagery does play a role in information processing. We will define mental
imagery broadly as the processing of perceptual-like information in the absence of an
external source for the perceptual information. We will consider the following questions: • How do we process the information in a mental image? • How is imaginal processing related to perceptual processing? • What brain areas are involved in mental imagery? • How do we develop mental images of our environment and use these
to navigate through the environment?
•Verbal Imagery versus Visual Imagery
There is increasing evidence from cognitive neuroscience that several different
brain regions are involved in imagery. This evidence has come both from studies
of patients suffering damage to various brain regions and from studies of the
brain activation of normal individuals as they engage in various imagery tasks.
In one of the early studies of brain activation patterns during imagery, Roland
and Friberg (1985) identified many of the brain regions that have been investigated
in subsequent research. They had participants either mentally rehearse a
word jingle or mentally rehearse finding their way around streets in their neighborhoods.
The investigators measured changes in blood flow in various parts of
the cortex. Figure 4.1 illustrates the principal areas they identified.When participants
engaged in the verbal jingle task, there was activation in the prefrontal cortex
near Broca’s area and in the parietal-temporal region of the posterior cortex
FIGURE 4.1 Results from
Roland and Friberg’s (1985)
study of brain activation
patterns during mental imagery.
Regions of the left cortex
showed increased blood flow
when participants imagined
a verbal jingle (J) or a spatial
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near Wernicke’s area. As discussed in Chapter 1, patients with damage to these
regions show deficits in language processing. When participants engaged in the
visual task, there was activation in the parietal cortex, occipital cortex, and temporal
cortex. All these areas are involved in visual perception and attention, as
we saw in Chapters 2 and 3.When people process imagery of language or visual
information, some of the same areas are active as when they process actual
speech or visual information. Cognitive Psychology And Its Implications.
An experiment by Santa (1977) demonstrated the functional consequence
of representing information in a visual image versus representing it in a verbal
image. The two conditions of Santa’s experiment are shown in Figure 4.2. In
the geometric condition (Figure 4.2a), participants studied an array of three
geometric objects, arranged with one object centered below the other two.
This array had a facelike property—without much effort, we can see eyes and a
mouth. After participants studied the array, it was removed, and they had to
hold the information in their minds. They were presented with one of several
different test arrays. The participants’ task was to verify that the test array contained
the same elements as the study array, although not necessarily in the same
94 | Mental Imagery
Triangle Circle Square
Triangle Circle Arrow
(a) Geometric condition
(b) Verbal condition
FIGURE 4.2 The procedure followed in Santa’s (1977) experiment demonstrating that visual
and verbal information is represented differently in mental images. Participants studied an initial
array of objects or words and then had to decide whether a test array contained the same
elements. Geometric shapes were used in (a), words for the shapes in (b).
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spatial configuration. Thus, participants should
have responded positively to the first two test
arrays and negatively to the last two. Santa was
interested in the contrast between the two positive
test arrays. The first was identical to the
study array (same-configuration condition). In
the second array, the elements were displayed
in a line (linear-configuration condition). Santa
predicted that participants would make a positive
identification more quickly in the first case,
where the configuration was identical—because,
he hypothesized, the mental image for the study
stimulus would preserve spatial information. The
results for the geometric condition are shown in
Figure 4.3. As you can see, Santa’s predictions were confirmed. Participants were
faster in their judgments when the geometric test array preserved the configuration
information in the study array.
The results from the geometric condition are more impressive when contrasted
with the results from the verbal condition, illustrated in Figure 4.2b.
Here, participants studied words arranged exactly as the objects in the geometric
condition were arranged. Because it involved words, however, the study stimulus
did not suggest a face or have any pictorial properties. Santa speculated that participants
would read the array left to right and top down and encode a verbal
image with the information. So, given the study array, participants would encode
it as “triangle, circle, square.” After they studied the initial array, one of the test
arrays was presented. Participants had to judge whether the words were identical.
All the test stimuli involved words, but otherwise they presented the same
possibilities as the test stimuli in the geometric condition. The two positive stimuli
exemplify the same-configuration condition and the linear-configuration
condition. Note that the order of words in the linear array was the same as it
was in the study stimulus. Santa predicted that, unlike the geometric condition,
because participants had encoded the words into a linearly ordered verbal image,
they would be fastest when the test array was linear. As Figure 4.3 illustrates,
his predictions were again confirmed.
Different parts of the brain are involved in verbal and visual imagery,
and they represent and process information differently.
Most of the research on mental imagery has involved visual imagery, and this
will be the principal focus of this chapter. One function of mental imagery is to
anticipate how objects will look from different perspectives. People often have
the impression that they rotate objects mentally to achieve perspective. Roger
Shepard and his colleagues have been involved in a long series of experiments
Visual Imagery | 95
Reaction time (s)
FIGURE 4.3 Results from
Santa’s (1977) experiment. The
data confirmed two of Santa’s
hypotheses: (1) In the geometric
condition, participants would
make a positive identification
more quickly when the configuration
was identical than when
it was linear, because the visual
image of the study stimulus
would preserve spatial information.
(2) In the verbal condition,
participants would make a
positive identification more
quickly when the configuration
was linear than when it was
identical, because participants
had encoded the words from
the study array linearly, in
accordance with normal reading
order in English.
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on mental rotation. Their research was among the first to study the functional
properties of mental images, and it has been very influential. It is interesting to
note that this research was inspired by a dream (Shepard, 1967): Shepard awoke
one day and remembered having visualized a 3-D structure turning in space.
He convinced Jackie Metzler, a first-year graduate student at Stanford, to study
mental rotation, and the rest is history.
Their first experiment was reported in the journal Science (Shepard &
Metzler, 1971). Participants were presented with pairs of 2-D representations
of 3-D objects, like those in Figure 4.4. Their task was to determine whether the
objects were identical except for orientation. The two objects in Figure 4.4a
are identical, as are the two objects in Figure 4.4b, but in both cases the pairs
are presented at different orientations. Participants reported that to match the
two shapes, they rotated one of the objects in each pair mentally until it was
congruent with the other object. There is no way to rotate one of the objects in
Figure 4.4c so that it is identical with the other.
The graphs in Figure 4.5 show the times required for participants to decide
that the members of pairs were identical. The reaction times are plotted as a
function of the angular disparity between the two objects presented. The angular
disparity is the amount one object would have to be rotated to match the other
object in orientation. Note that the relationship is linear—for every increment
in amount of rotation, there is an equal increment in reaction time. Reaction
time is plotted for two different kinds of rotation. One is for 2-D rotations
(Figure 4.4a), which can be performed in the picture plane (i.e., by rotating the
page); the other is for depth rotations (Figure 4.4b), which require the participant
to rotate the object into the page. Note that the two functions are very
similar. Processing an object in depth (in three dimensions) does not appear
to have taken longer than processing an object in the picture plane. Hence,
participants must have been operating on 3-D representations of the objects in
both the picture-plane and depth conditions.
These data might seem to indicate that participants rotated the object in a
3-D space within their heads. The greater the angle of disparity between the two
objects, the longer participants took to complete the rotation. Though the
participants were obviously not actually rotating a real object in their heads,
the mental process appears to be analogous to physical rotation.
96 | Mental Imagery
(a) (b) (c)
FIGURE 4.4 Stimuli in the Shepard and Metzler (1971) study on mental rotation. (a) The
objects differ by an 80° rotation in the picture plane (two dimensions). (b) The objects differ
by an 80° rotation in depth (three dimensions). (c) The objects cannot be rotated into
congruence. (From Metzler & Shepard, 1974. Reprinted by permission of the publisher. © 1974 by Erlbaum.)
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There has been a great deal of subsequent research examining the mental
rotation of all sorts of different objects. The typical finding is that the time
required to complete a rotation does vary with the angle of disparity. In recent
years, there have been a number of brain-imaging studies that looked at what
regions are active during mental rotation. Consistently, the parietal region
(roughly the region labeled R at the upper back of the brain in Figure 4.1) has
been activated across a range of tasks. This finding corresponds with the results
we reviewed in Chapter 3 showing that the parietal region is important in spatial
attention. Some tasks involve activation of other areas. For instance, Kosslyn,
DiGirolamo, Thompson, and Alpert (1998) found that imagining the rotation of
one’s hand produced activation in themotor cortex.
Neural recordings of monkeys have provided some evidence about neural
representation during mental rotation involving hand movement. Georgopoulos,
Lurito, Petrides, Schwartz, and Massey (1989) had monkeys perform a task in
which they moved a handle at a specific angle in response to a given stimulus. In
the base condition, monkeys just moved the handle to the position of the stimulus.
Georgopoulos et al. found cells that fired for particular positions. So, for
instance, there were cells that fired most strongly when the monkey was moving to
the 9 o’clock position and other cells that responded most stronglywhen the monkey
moved to the 12 o’clock position. In the rotation condition, the monkeys had
to move the handle to a position rotated some number of degrees from the stimulus.
For instance, if the monkeys had to move the handle 90° counterclockwise and
the stimulus appeared at the 12 o’clock position, they would have to move the
handle to 9 o’clock. If the stimulus appeared at the 6 o’clock position, they would
have to move to 3 o’clock. The greater the angle, the longer it took the monkeys
Visual Imagery | 97
Angle of rotation (degrees)
0 40 80 120 160