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14.12.2015
Chapter 10
Imagery
Some Questions to Consider
• How do “pictures in your head” that you
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Experiencing Imagery
• Answer the following questions:
– • How many windows are there in front of
the house where you live?
– • How is the furniture arranged in your
bedroom?
– • Are an elephant’s ears rounded or
pointy?
– • Is the green of grass darker or lighter
than the green of a suit used in military
service?
create by imagining an object compare to the
experience you have when you see the actual
object?
What happens in your brain when you create
visual images with your eyes closed?
How does damage to the brain affect the
ability to form visual images?
How can we use visual imagery to improve
memory?
What Is Imagery?
• Mental imagery: experiencing a sensory
impression in the absence of sensory input
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– Visual imagery: “seeing” in the absence of
a visual stimulus
What about auditory imagery?
Imagine all the people living life in peace...
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Imagery and the Cognitive Revolution
• Developed ways to measure behavior that
could be used to infer cognitive processes
– Paired-associate learning
• boat–hat or car–house
• Alan Paivio (1963): it was easier to remember
concrete nouns, like truck or tree, that can be
imaged, than it is to remember abstract
nouns, like truth or justice, that are difficult to
image.
Imagery and the Cognitive Revolution
Imagery and the Cognitive Revolution
• Paivio (1963, 1965)
– Paivio inferred cognitive processes by measuring
memory
– Memory for words that evoke mental images is
better than those that do not
– Conceptual-peg hypothesis
• concrete nouns create images that other words
can “hang onto.” boat-hat
Task: to indicate, as rapidly as possible, whether the two
pictures were of the same object or of different objects.
• Shepard and Meltzer (1971)
– inferred cognitive processes by using ‘Mental
chronometry’: the amount of time needed to
carry out cognitive tasks
– Participants mentally rotated one object to see if
it matched another object
Caption: Stimuli for Shepard and Metzler’s (1971) mental rotation
experiment.
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Mental rotation by Shepard.
Q: these are the same or not?
The time it takes to do this task
depends on how different the
angles were between the two
views.
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Imagery and Perception
Imagery and Perception
• Do imagery and perception share the same
mechanisms?
• Although mental images are not vivid or long
lasting as perception...
• Kosslyn: participants create mental images and
then scan them in their minds. (Mental scanning)
• We act as if our mental images are physical
entities
– Scanning
– Acuity
• Kosslyn (1973)
– Memorize picture, create an image of it
– In image, move from one part of the picture to
another
Caption: Stimulus for Kosslyn’s (1973) imagine-scanning experiment.
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Imagery and Perception
• Kosslyn (1973)
• Q: Perception is spatial.
What about imagery? Is imagery spatial or not?
• It took longer for participants to mentally move
long distances than shorter distances
Imagery and Perception
• Lea (1975) opposite to Kosslyn
– More distractions (other interesting parts,
such as the cabin) when scanning longer
distances may have increased reaction
time
– Like perception, imagery is spatial
Imagery and Perception
• So, Kosslyn et al. (1978) did another experiment
– Imagine an island with 7 locations,
Imagery and Perception
– It took longer to scan between greater distances
– Visual imagery is spatial
– scan between two places
on a map (21 possible mental
Trips
Participants mentally traveled
between the various locations
on the island.
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Is Imagery Spatial or Propositional?
• Kosslyn: mechanism responsible for imagery
involves a spatial representation
• But Pylyshyn (1973) disagreed.
• Spatial representation is an epiphenomenon.
something is happening in the mind, but don’t tell us
how it is happening.
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– Accompanies real mechanism but is not actually
a part of it.
Analogy: The lights may indicate that something is
going on inside the computer, but they don’t
necessarily tell us what is actually happening.
Proposed that imagery is propositional
– Can be represented by abstract symbols
Caption: Propositional and spatial, or depictive, representations of
“the cat is under the table.”
Is Imagery Spatial or Propositional?
• Pylyshyn (1973)
– Imagery debate
• Proposition representation: symbols,
language
• Spatial representation: pictures
The words indicate parts of the boat, the length of the lines
indicate the distances between the parts, and the words in
parentheses indicate the spatial relations between the parts!
This is how the visual appearance of this boat can be
represented propositionally
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Is Imagery Spatial or Propositional?
• Finke and Pinker (1982)
– Participants judge whether arrow points to dots
previously seen
– Longer reaction time when greater distance
between arrow and dot (as if they were
mentally “traveling”)
Comparing Imagery and Perception
• Size in the Visual Field
• how imagery is affected by the size of an
object in a person’s visual field.
– Not instructed to use visual imagery
– No time to memorize,
This is what happens during perception process? What about imagery?
Comparing Imagery and Perception
• Relationship between viewing distance and ability
to perceive details (happens in imagery?) Kosslyn
– Imagine small animal next to large animal
• ‘Does a rabbit have whiskers?’ asked his
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participants to find that part of the animal in their
mental image and to answer as quickly as
possible
answered question about the rabbit more rapidly
when it filled more of the visual field. So, Quicker
to detect details on the larger animal.
Caption: These pictures represent images that Kosslyn’s (1978)
participants created, which filled different portions of their visual field.
(a) Imagine elephant and rabbit, so elephant fills the field. (b) Imagine
rabbit and fly, so rabbit fills the field. Reaction times indicate how long
it took participants to answer questions about the rabbit.
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Comparing Imagery and Perception
• Mental-walk task
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– imagine that they were walking toward their
mental image of an animal.
Their task was to estimate how far away they were
from the animal when they began to experience
“overflow”—when the image filled the visual field
Move closer to small animals than to large animals
– Images are spatial, like perception
Even more interesting, not one of Perky’s 24 participants noticed that
there was an actual picture on the screen. Mistake actual picture for a
mental image
Interactions of Imagery and Perception
• How do they interact with one another?
• Perky (1910)
• Perky asked her participants to “project” visual
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images of common objects onto a screen, and then
to describe these images.
Perky was back-projecting a very dim image of this
object onto the screen
Interestingly, the participants’ descriptions of their
images matched the images that Perky was
projecting.
Martha Farah (1985) instructed her
participants to imagine either the letter H or
T on a screen.
They pressed a button that caused two
squares to flash, one after the other.
One of the squares contained
a target letter, which was either an H or a
T. The participants’ task was to indicate
whether the letter was in the first square or
the second one.
Caption: Participant in Perky’s (1910) experiment. Unbeknownst to
the participants, Perky was projecting dim images onto the screen.
Result: The target letter was detected more
accurately when the participant had been
imagining the same letter rather than the
different letter.
perception and imagery share mechanisms.
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NEUROPSYCHOLOGICAL CASE STUDIES
Removing Part of the Visual Cortex Decreases
Image Size
NEUROPSYCHOLOGICAL CASE STUDIES
Removing Part of the Visual
Cortex Decreases Image Size
– Patient M.G.S. (her right occipital lobe removed)
– Martha Farah and et al. (1993) had M.G.S. perform
the mental walk task!
– Before the operation: M.G.S. was about 15 feet
from an imaginary horse before its image
overflowed.
Why? because removing part of
the visual cortex reduced the
size of her field of view, so the
horse filled up the field when
she was farther away!
– After the operation: it was 35 feet.
Dissociations between Imagery and Perception
NEUROPSYCHOLOGICAL CASE STUDIES
• Damage to the parietal lobes can
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cause a condition called unilateral
neglect.
The patient neglected the left side
of his mental image, just as he
neglected the left side of his
perceptions.
• one function present and another function absent!
• Guariglia and coworkers (1993)
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– Brain-damaged patient
– Patient’s perceptions intact, but mental images
were impaired
R.M. (normal perception but impaired imagery)
– Damage to occipital and parietal lobes
– Could draw accurate pictures of objects in front of
him
– Could not draw accurate pictures of objects from
memory (using imagery)
– Problem at on imagery: “A grapefruit is larger than
an orange”
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Dissociations between Imagery and Perception
• C.K. (perception is impaired but imagery is normal)
– Visual agnosia (the inability to visually recognize
objects.)
– Could draw objects in great
detail from memory
(using imagery)
– Inability to name pictures of
objects, even his own drawings,
in front of him
Making Sense of Neuropsychological Results
• Evidence for a double dissociation between
imagery and perception
– Indicates separate mechanisms.
• Also evidence for shared mechanisms
Explains C.K. and R.M. but not M.G.S.
Making Sense of Neuropsychological Results
• Behrmann and coworkers (1994)
– Mechanisms partially overlap
– Visual perception involves bottom-up processing;
located at lower and higher visual centers.
– Imagery is a top-down process; located at higher
visual centers. (in higher brain areas that are
responsible for memory.) Mental images do not
depend on activation of cortical areas, such as
the visual cortex, because there is no input that
needs to be processed.
Caption: Perception are located at both lower and higher visual centers and imagery are
located mainly at higher levels (Behrmann et al., 1994). The general locations of
damage for C.K. and R.M. are indicated by the vertical arrows. These locations can
explain why R.M. has trouble creating images but can still perceive and why C.K. has
a perceptual problem but can still create images.
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Imagery and Perception
• Differences in experience
– Perception is automatic and stable
– Imagery takes effort and is fragile
Imagery and Perception
• Later research has shown that people can
• Chalmers and Reisberg (1985)
– Perceptually, it is easy to “flip” between these
two perceptions.
– Had participants create mental images of
ambiguous figures.
– Difficult to flip from one perception to another
while holding a mental image of it
Using Imagery to Improve Memory
• How can you use the power of imagery to help
you remember things better?
• Method of loci (Yerleştirme yöntemi)
– Visualizing items to be remembered in
different locations in a mental image of a
spatial layout
– Placing images at locations can help with
retrieving memories later.
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manipulate simpler mental images.
– Ronald Finke and coworkers (1989)
– imagine a capital letter D, and then rotate it 90
degrees to the left and place a capital letter J at
the bottom, they reported seeing an umbrella.
Imagery and perception have many features in
common, but there are also differences between
them.
Using Imagery to Improve Memory
• Method of loci
1. Pick a place with a spatial layout
that is very familiar to you
2. pick 5 to 7 things that you want
to remember
3. place each thinng at a location
4. try mentally “walking” this path
while trying to recall
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Using Imagery to Improve Memory
• Method of loci
• Pegword technique (Sözcük asma)
Bower (1970)
Left Column
Egg
Cat food
Tomato
Banana
Whiskey
Using Imagery to Improve Memory
Right Column
garage outside
garage inside
front door
coat hanger
sink at kitchen
Using Imagery to Improve Memory
• Pegword technique (Sözcük asma)
e.g.
Bir, bir piredir.(fil)
İki bir iptir. (ayakkabı)
Üç bir süttür.(ağaç)
Dört, bir gözdür.
Beş bir balıktır.
Altı bir martıdır.
Yedi bir kedidir.
Sekiz bir sakızdır.
– Associate items to be remembered with
concrete words
– Pair each of these things with a pegword
– Create a vivid image of things to be
remembered with the object represented
by the word
Using Imagery to Improve Memory
• Recalling Words
Trabzon Trenin’de Cin Hortladı.
El bileklerindeki kemiklerTrapezium, Trapezoideum,
Capitutum, Havuantum
Dünyanın en uzun nehirleri: Misissipi; Nil ve Sari Irmak
Ma Ni Sa
BAHT
Temel terapi ekolleriBilişsel, Analitik, Hümanistik
NEWSOCEAN – 5 Factor personality
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Using Imagery to Improve Memory
• Recalling people’s names
Relating the name with the face of that person.
One way rhyming
e.g. Erdem-demir gibi güçlü bir er
Ayten-bembeyaz, ay gibi bir ten
Second way finding a salient feature at the face and
relating it with the name.
e.g. Koca kulaklı Ayten-anten
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