• Representing knowledge
o One of the earliest debates in psychology concerns the role of imagery in thought
o Imagery is a mental representation of something that isn’t currently present.
o Different than symbolic representation which is an arbitrary mental representation
of a concept.
o According to Pavlo’s dual code theory, thoughts can be represented in two ways:
As analogue codes/ depictive representations (images)
As symbolic codes (words)
o Dual code theory describes only one way of representing images – as depictive
representations/ analogue codes
o Propositional theory
Images are epiphenomena of underlying propositional networks.
• Something that accompanies the real mechanism but is not
actually part of the mechanism.
o E.g lights flashing as a mainframe computer carries out its
• Where relationships can be represented by abstract symbols,
such as an equation, or a statement such as “the cat is under the
A proposition is the smallest unit of knowledge that can stand as an
• E.g the smallest unit about which it makes sense to make a
• If we can say its true or false, it’s a proposition
• Basically a question, not a statement.
Not tied to any specific modality. Propositions preserve only the meaning of an item
Basically, proposition is an idea, and from that you can form pictures
E.g Janet gave a bright red apple to mr.smith who is her math teacher
• MULTIPLE PROPOSITIONS:
o Janet game mr.smith an apple
o The apple is bright red
o Mr.smith is a math teacher
Propositions consist of an agent and a relation
o The ‘thing’ you’re referring to (noun)
o Explains what’s happening to the agent (verb, adjective,
• Relation (agent
o the duck is wet -> wet (duck)
o the duck quacks -> quacks (duck)
o The functional-equivalence hypothesis believes all images are represented as
analogue codes. Basically the same thing as dual code theory.
Finke describes 5 days that images can be similar
• 1. Transformational equivalence
o Imagined and physical movements use the same laws of
• 2. Spatial equivalence
o Arrangement of elements in images are the same as those
in physical objects
o E.g emergency exits, maintained through images • 3. Implicit encoding
o Information about physical objects can be attained from
images even though not stored explicitly
o Info imagined is as accurate as real stimuli
• 4.structural equivalence
o Construction of images and physical objects uses similar
o Creating images like we do in real life
E.g a square for a house and triangle for the roof.
• 5. Perceptual equivalence.
o Similar brain mechanisms are used for imagery and
o Imagery and visual perception use the same brain area.
o Mental Rotation
• To investigate whether mental rotation is analogous to physical
• Decide whether two images are the same of different
• IV –angle of rotation
• IV – same of different
• DV – response time
We can conclude that mental rotation IS analogous to physical rotation
• Image scanning o Was told to imagine an island, with different locations. Take a quick glance at the
picture, closed eyes and then asked where a certain location was from one
another. Subjects would guess where they were to test their ability of image
• Demand characteristics and experimenter expectancy
o The nature of the task may ‘demand’ that participants behave in a certain way
o Experiments might unknowingly bias participants to behave a certain way
E.gintons-petersons (1983) “experimenters” influenced the outcome of
• Image scaling (spatial equivalence)
o imagine a rabbit standing next to an elephant
does an elephant have eyelashes?
• Response time would be FAST
Does a rabbit have eyelashes?
• Response time would be SLOW
Measure reaction time
o Imagine a rabbit standing next to fly
Does a fly have whiskers?
• Response time would be SLOW
Does a rabbit have whispers?
• Response time would be FAST
Idea of getting closer makes things longer, thus, the response time
corresponds to how close you need to be with the object in order for it you
to identify it.
o Imagine an elephant-sized rabbit standing next to a rabbit-sized elephant
Does an elephant have eye lashes?
• Response time SLOW
Does a rabbit have eye lashes? • Response time FAST
This shows that it exerts the same effect.
Idea of zooming in takes time.
• Difficult and ambiguous figures
o Carmichael, Hogan, Walters (1932)
Provides early evidence that images are stored according to their
meaning instead of like a mental snapshot
When presented with a shape (e.g star of david), were asked what shape
was present. Only 14% of participants got it right
Shows that we’re not storing that image, we’re storing something else.
• Image complexity
o Kosslyn et al
5 squares in the shape of a cross
Two overlapping rectangles
• Interference and Priming
o If imagery is analogous to real perception, than real and imaged stimuli should
interact with each other.
o Segal &Fusella
Did the test to show that the auditory and sensory part of the brain are
separate and that having two stimuli affecting the same part of the brain
causes that part of the brain to have conflict, thus slow detection rate.
• Neuropsychological evidence
o Eye movements are similar when looking at an object and later imagining the
o Similar brain areas are active during real perception and imagery
But Farah and colleagues provide evidence for a separate imaging area
in the brain (left fusiform gyrus) o Patients with visual spatial neglect have similar problems with imagery.
o Case studies of brain damaged individuals provides mixed evidence
MGS had normal imagery prior to unilateral removal of occipital cortex,
but reduced visual field and imagery after surgery
CK had a serious deficit in form perception but could draw items from
LH had intact visyal perception, mental rotation, image scanning, size
scaling, but could not answer questions verbally about mental images
Sometimes we have imagery and visual perception and vice versa
• Analogous vs propositions
o Evidence indicates that when we form mental images, they are analogous to real
o Experiments that find support for propositions usually involve relatively complex
objects and/or require us to assign meaning to the percept.
o We are able to use both analogous images and propositions.
• How is knowledge organized?
o What is the structure of semantic memory?
o Knowledge organized into categories.
A category is group of object that belong together and have something in
The most commonly studied function of concepts
The process by which things are placed into groups called categories
• E.g seeing vehicles on street cause you to put them in the
category cars, SUV’S, chervorlet, Fords, etc.
Categories are tools that are essential for our understanding of the world.
One important function is helping us understand individual cases we have
never seen before.
• E.g saying the furry animal across the street is a cat provides a lot
of information about it. Categories been called ‘pointers to knowledge’
Can also help us understand behaviours that we might find baffling
• E.g seeing a man with the left side of his face painted black and
right side gold, is weird but once you know hes going to a football