Visual Imagery Flashcards
What is a visual image?
(Visual imagery)
= Seeing an object or scene in the absence of a visual
stimulus
(in front of one’s mind’s eye)
-> Often part of episodic memory
(remembering past experience)
What makes visual imagery important in everyday life?
(Visual imagery)
Navigation
-> Imagining a path,
-> recounting how many blocks one would have to walk
Visual planning
-> Packing luggage in a car
-> arranging furniture in living room
Problem solving
-> Drawing visual analogies to help solve problems
What types of mental imagery of sensory domains are there?
(Visual imagery)
Gustatory imagery
(Taste)
= using vivid language to create mental images of textures and flavors, enabling readers to imagine what something tastes like
Olfactory imagery
(Smell)
= using descriptive language to create mental images of scents, enabling readers to imagine what something smells like
Tactile imagery
(Touch)
= using descriptive language to create mental images of textures and physical sensations, enabling readers to imagine what something feels like
Auditory imagery
(Sound)
= a form of mental imagery that is used to organize and analyze sounds. It is used to explain things, ideas, and actions using sounds that appeal to our sense of hearing
What are the properties of visual imagery?
(Visual imagery)
-> can be voluntarily initiated
(i want to remember…)
-> can be triggered by an outside stimulus
(“imagine…”, “think about…”)
-> can be spontaneously
(flashbacks, daydream, ohrwurm)
-> can be intrusive and unwanted
(anxiety disorders, ptsd)
What were critics and debates surrounding imagery?
(Visual imagery)
Watson (1928)
-> images as “unproven” and “mythological”, therefore not worthy of study
Paivio (1963)
-> better memory for imaginable nouns than abstract ones
Shepard & Metzler (1971)
Mental rotation experiment
=> is there a spatial correspondance between imagery an perception?
How are perception and imagery connected?
(perception & imagery)
Kosslyn (1973)
Image scanning experiment
Task
-> Memorize image
-> Create mental image of the boat
-> Focus on flagpole
-> Look fro an anchor in mental image
Hypothesis
-> if imagery is spatial like perception
-> it should take longer to look for objects that are far way
(larger parts of the image have to be scanned)
Result
-> Participants took longer to find objects that are far
away
Alternative explanation
-> Maybe there are more interisting things “on the way” for objects
Kosslyn (1978)
Image scanning replication
Task
-> More controlled scanning of mental image
- imaginery island, no visual features
- imagine travelling from location A to location B
Result
-> RT longer for larger scanning distance
What is the argument for the spatial vs propositional representation
(perception & imagery)
Kosslyn
-> imagery based on spatial or pictorial representation
Pylyshyn
-> imagery based on prpositional representation
(using abstract symbols or language)
=> instead of having an image in mind we actually have a description (abstract symbols / language) of the image in mind
-> just because our experience of imagery is spatial, it does not mean that the underlying representation is also spatial
-> spatial experience of imagery as epiphemenomenon
How does Pyshylyn represent proposition?
(perception & imagery)
Propositional representation results
-> representation is not spatial, but length of the lines represents distance in image
Compare semantic networks for knowledge representation
Why does it take us longer to scan?
(perception & imagery)
Pylshyn
Tacit knowledge explanation
-> scanning time increases with distance between points
-> response on what they know about what happens
when they are looking at areal scene
-> results not due to a spatial representation but a
behavioural strategy
Flinke & Pinker (1982)
Counter evidence
-> present dots briefly, then ask if arrow pointed at
one of the dots
-> took participants longer when distnace between
dot an arrow was larger
-> Evidence for spatial representation under
conditions with no “tacit knowledge”
Do imagery and perception share representation?
(perception & imagery)
Kosslyn (1978)
Size in the visual field
instruction
-> imagine two animals, the bigger one filling your visual field
Task
-> Answer questions about rabbit as quickly as possible Result
-> RTs were longer when rabbit was imagined smaller Interpretations
-> Participants “could not see” details when rabbit was small in their imagined visual field
(like actual visual field)
Broggin (2012)
RT to imagined and perceived stimuli
Task
-> Respond as quickly as possible to imagined or actually
presented stimulus
Manipulation
-> Luminance, contrast, motion or orientation of
imagined / presented stimulus
Result
-> Effect of stimulus properties both when they are
imagined and actually presented
Interpretation
-> Overlap in the structural representations of perception and imaginery
Perky (1910)
Interactions of imagery and perception
Task
-> imagine banana mentally “project” it on a screen and describe it
Manipulation
-> secretly project dim image of a banana on screen
(low luminanced)
Result
-> Participant’s description matched projected image
Interpretation
-> Because imagery and perception interact, they must be based on the same mechanisms
What is the role of gaze in mental imagery?
(perception & imagery)
= When we perceive visual input, we move our eyes
around to collect relevant information
-> we can observe similar patterns of eye movements when participants imagine visual stimuli
=> when eye movements are similar during perception and imagery memory for the stimulus is more accurate
=> when eye movements are restricted during imaginery, memory recall is less accurate
Where does evidence for a shared representation of imagery perception come from?
(perception & imagery)
-> image-scanning studies
-> Eye-tracking studies on imagery
-> imagery studies
(imagine stimuli in different sizes, with different intensity)
What experiments contributed to the idea of shared neural basis of imagery and perception?
(neural basis of imagery)
Kreisman (2000)
Single-cell recordings
-> epilepsiy patients that had electrodes implanted into medial temporal lobe
=> found imagery neurons
- neurons that respond similarly to perceiving and imagining objects
Goldenberg (1989)
=> Primary visual cortex active when answering questions incolving imagery
Le Bihan (1993)
=> Primary visual cortex activated by both perceived and imagined stimuli
Ganis (2004)
=> Both perception and imagery activate frontal lobe
areas, but perception activates occipital lobe stronger
Kosslyn (1995)
topographic organization of neural activity in visual cortex
-> visual presentation of small objects activates small
area of visual cortex compared to larger objects
=> similar pattern for imagined objects of different sizes
Kosslyn (1999)
Causal role of visual cortex in imaginery
-> applied TSM to visual cortex during perception /
imagery task
-> TMS led to similar impairments for perception and
imagery
=> causal evidence that visual cortex is involved in
imagination of visual stimuli
What is the evidence in favour shared neural basis of imagery and perception in patient studies?
(neural basis of imagery)
Patients who lost ability to see color due to brain damage
-> also report being unable to create colors through
imagery
Patients with hemispatial neglect as a result of right parietal lobe damage
-> also neglect affected half of their visual imagery
=> strong causal evidence
What is the evidence against shared neural basis of imagery and perception in patient studies?
(neural basis of imagery)
Patients with lesion in right frontal lobe show selective neglect only for imagery
=> not for perception
patient rm
-> could draw objects put in front of them
-> could not draw same object from memory
-> could not answer questions depending on imagery
(intact perception - not intact imagery)
patien ck
-> difficulties recognizing objects
-> could draw objects from memory
-> was not able to recognize objects he drew himself later
(intact imagery - not intact perception)
=> double dissociation
