2. Chapter 10: Visual Knowledge
Lecture Outline
Visual Imagery
Long-Term Visual Memory
The Diversity of Knowledge
3. Visual Imagery
A variety of day-to-day problems seem to
require the use of visual imagery
How many windows are in your apartment?
Was David in class yesterday?
Will this sweater look good with your blue
pants?
What is the nature of these mental
images?
4. Visual Imagery
Francis Galton (1883)
Introspection to study mental imagery
Self-reports suggested they could inspect mental images
as pictures
The participants also differed widely in the amount of
detail their mental images seemed to contain. (Or were
these differences in self-reporting style?)
6. Visual Imagery
Chronometric studies
Ask participants to manipulate the mental
images
Observe how long these manipulations take
7. Visual Imagery
Kosslyn (1976) asked participants to answer
yes/no questions about their mental images.
Imagined cat, confirm that cats have heads faster
compared to confirming that cats have claws (mental
imagery)
The reverse was true if the participants were asked to
think about cats, not to imagine them (propositional
knowledge)
This suggests that as the mode of representation
changes, so does the pattern of information
availability
9. Visual Imagery
Imagined distance corresponds
to real distance
Thus, mental images seem to preserve the spatial layout and geometry of
the represented scene.
12. Visual Imagery
The greater the angle,
the longer the time
As if they were rotating the images in real life
13. Visual Imagery
Demand character
Did image-scanning and mental-rotation
experimenters somehow cue people?
Even without instruction, participants still form
images
14. Visual Imagery
Less accurate when
signal and image are the
same
More likely to wrongly
choose that the stimulus
matches the image when
signal and image are
both visual or auditoryMental imagery seems to use perceptual
mechanisms.
Visual imagery interferes with detecting dim
visual stimuli, and auditory imagery interferes
with detecting quiet tones.
15. Visual Imagery
However, if we are imagining a stimulus
related to the one we are about to
perceive, facilitation occurs.
Imagery
Can interfere with perception (mismatching)
Can facilitate perception (matching)
16. Visual Imagery
Occipital areas used for early visual
processing
Active during visual imagery
Patients with unilateral neglect may also
neglect the left side of space in their mental
images
Transcranial magnetic stimulation (TMS)
disrupts mental imagery
17. Visual Imagery
Patient can only see the right side of the plaza
Patients with unilateral neglect may also neglect the left side of space in
their mental images.
19. Visual Imagery
Functional equivalence between
imagery and perception.
Visual acuity higher—can see
two dots
Visual acuity lower—need
more space to see two dots
For both perception and imagery, acuity is greatly reduced if the dots are
not in the center of vision.
20. Visual Imagery
People who have been blind since birth
also demonstrate the same effects in
mental-rotation or image-scanning tasks,
with response time being proportional to
the distance traveled
Thus, we need to distinguish between
visual imagery and spatial imagery
Spatial imagery may be based in
movement or body imagery, or it may be
abstract and not tied to any one sense
21. Visual Imagery
Vivid imagers versus non-imagers
Report seeing images better
Self-reported “vivid imagers” perform no
differently than “non-imagers” on tasks that
depend on spatial imagery.
Vivid imagers better for visual imagery
22. Visual Imagery
Eidetic or
photographic memory
Extremely rare
Found in some autistic
individuals
eidetic imagery
23. Visual Imagery
Mental images different from pictures
Perception is not neutral and goes beyond the
information given
Interpretations are present in images
25. Visual Imagery
Thus, images (like percepts) are
organized depictions
One way to think about mental images is
as a package that includes the depiction
itself as well as a perceptual reference
frame
For instance, the duck/rabbit image,
understood as a duck, is associated with
the reference frame “facing to the left”
27. Visual Imagery
Sometimes putting an idea down on paper can
help make a discovery that requires a change in
the reference frame
28. Visual Imagery
Mental images
Alternative to verbal description
Spatial layout and geometry are preserved
Reflect perceptual interpretation and are
associated with reference frames
30. Long-Term Visual Memory
Images in long-term memory
Stored in a piecemeal fashion
Must activate representation of image frame
Elaborate on this frame
Images that have more parts or detail take
longer to create
32. Long-Term Visual Memory
Long-term visual memory
Image files
Recipes or instructions for how to construct an
active mental image of the object or shape
May represent visual information in terms of
propositions, or verbal labels
33. Long-Term Visual Memory
Will have more accurate
memory for something that
is either blue or green
Will have less accurate
memory
37. Long-Term Visual Memory
Dual coding
High-imagery words, for instance, can be
coded as both word and image
Low-imagery words only have a verbal code
38. Long-Term Visual Memory
Studies of memory for pictures illustrate
ways in which long-term visual memory
reflects general principles of memory,
such as
Primacy and recency
Encoding specificity
Schemata or generic knowledge
Spreading activation and priming
Familiarity and source memory
39. Long-Term Visual Memory
Schematic retrieval
(Friedman, 1979) found that participants
failed to notice differences between previously
seen and new pictures if both were consistent
with a schema (e.g., a kitchen or barnyard)
Pictures that contained violations of a schema
(e.g., kitchen with a fireplace) were readily
noticed
40. Long-Term Visual Memory
Boundary extension
Information is filled in
that was not present in
the picture
41. The Diversity of Knowledge
Visual working memory is based in imagery and
uses perceptual, spatial representations
Image scanning, rotation, zooming
Visual long-term memory is based on
propositional knowledge and shares many
representational principles with other forms of
long-term memory
Spreading activation, priming, schematic knowledge
43. 1. Based on image-zooming experiments,
which of the following would participants
be slowest to identify in a mental image?
a) the whiskers of a cat standing alone
b) the ears of a rhinoceros positioned next
to a squirrel
c) the whiskers of a cat positioned next to an
ant
d) the wings of a butterfly positioned next to
a hippopotamus
44. 2. Participants answering questions about
geography might erroneously claim that San
Diego, California, is farther west than Reno,
Nevada, when in fact Reno is farther west.
This example suggests that spatial
information is sometimes
a) stored in long-term memory as propositions.
b) stored in short-term memory as propositions.
c) stored in long-term memory using a
perceptual code.
d) stored in short-term memory using a
perceptual code.
45. 3. Which of the following is evidence that the
brain areas involved in perception and
mental imagery are similar?
a) using TMS to disrupt Area V1 results in
parallel problems in vision and visual
imagery
b) a patient suffering from neglect syndrome
may neglect the left half of imagined
scenes
c) stroke patients who lose the ability to see
color also lose the ability to imagine color
d) all of the above
46. 4. What is the worst description of individual
differences in imagery ability?
a) Most people are able to form images.
b) Some people are good at visual imagery,
and others are good at spatial imagery.
c) Within visual imagery and spatial
imagery, most people have some
strengths and some weaknesses.
d) Imagery ability is fairly uniform from one
person to another.
47. 5. Which of the following is evidence that some
forms of imagery are spatial and not visual?
a) Blind people can complete mental-rotation
experiments as quickly and accurately as
sighted people.
b) There is no interference when people are
asked to judge the brightness of a light while
making a mental-rotation decision.
c) Patients such as L.H. may perform well on
spatial imagery tasks but fail on visual
imagery tasks.
d) all of the above
48. 6. Participants are asked to form mental
images of ambiguous pictures that were
viewed earlier. When asked to ___ the
image and then reinterpret it, they
succeed.
a) imagine
b) hear the sound of
c) imagine interacting with
d) draw
49. 7. Which of the following mental-image
reinterpretations would be the
HARDEST?
a) The sought-after discovery is compatible with the
image’s depiction but not its reference frame.
b) The sought-after discovery is compatible with the
image’s reference frame but not its depiction.
c) The sought-after discovery is compatible with both the
image’s depiction and its reference frame.
d) The sought-after discovery is compatible with neither the
image’s depiction nor its reference frame.
Hinweis der Redaktion
Correct answer: d
Feedback: Scanning is hardest when the target image is placed next to an image that is much larger. This makes the person zoom out.
Correct answer: a
Feedback: Rather than having an image, people store a “California is west of Nevada” type of memory. Hence, the map of each city is reconstructed with the verbal description rather than with an actual map.
Correct answer: d
Feedback: All of the statements are true.
Correct answer: d
Feedback: People vary in their ability for both spatial and visual imagery. However, everyone can perform both forms of imagery. Hence, it is not uniform.
Correct answer: d
Feedback: All of the above are correct statements.
Correct answer: d
Feedback: Drawing an item leads to the ability to change the frame of reference, which in turn leads them to be able to reinterpret it.
Correct answer: d
Feedback: When depiction and reference frame do not match, it is harder to reinterpret it.