Chapter 10: Visual Imagery Flashcards
Seeing in the absence of visual stimulation
Visual imagery
Refers to the ability to re-create the sensory world in the absence of physical stimuli
Mental imagery
Debate over whether thinking could occur with or without images
Imageless thought debate
What was Galton’s evidence that imagery is not required for thinking?
Observed people who had difficulty forming visual images
What is the behaviorist perspective on imagery?
Unproductive as visual images are invisible to everyone but the people experiencing them.
How did imagery become relevant to psychology again?
The cognitive revolution (measuring behaviour to infer cognitive processes)
Describe Alan Paivio’s work on memory
Found that it’s easier to remember concrete nouns as opposed to abstract nouns
Describe the paired-associate learning technique
Participants are presented with pairs of words during the study period, then presented during a test period. With the first word from each pair, their tasks is to recall the word that was paired with it during the study period.
Concrete nouns create images that other words can hang onto
The conceptual peg hypothesis
Determining the amount of time it takes to carry out various cognitive tasks.
Mental chronometry
Describe the mental rotation experiment
How long it takes to determine if the two images were the same or different, where the time it took to decide was related to how different the angles were as participants were using mental rotation
A process in which participants create mental images and then scan them in their mind
Mental scanning
Describe Kosslyn’s mental scanning experiment
Asked participants to memorize a picture of a boat and focus on one aspect of it, then look for another part of the boat and indicate whether they found it or not
What was concluded from Kosslyn’s mental scanning experiment?
Imagery and perception are spatial, and it should take longer to find parts that are further from the initial point
Representations in which different parts of an image can be described as corresponding to specific locations in space
Spatial representation
Representations which relationships can be represented by abstract symbols such as an equation or statement like “the cat is under the table”
Proportional representations
Something that accompanies the real mechanism but is not part of the mechanism
Epiphenomenon
Parts of the representation correspond to parts of the object.
Depictive representation
Which form of representation did the imagery debate settle on?
Spatial representation
Describe the evidence Kosslyn found with respect to images being spatial
Answered questions about imagined animals more quickly when they filled more of the visual field
Had to move closer for smaller animals than larger animals
Describe two experiments demonstrating how imagery affects perception and vice versa
Perky: Projected dim images onto a screen and asked participants to visualize and describe what the image represented, participants ended up describing the projected image without realizing
Farah: Target letter is detected more accurately when participants were imagining the same letter
Describe how evidence from neurons supports the relationship between imagery and perception
Neurons in different brain areas responding similarly to real and imagined stimuli demonstrates a physiological mechanism to imagery
How did brain imaging show the relationship between image size and the visual cortex?
Smaller images generated activity in the back of the visual cortex and large images in the front (same as perception)
Describe the results of Ganis’ fMRI study
Perception and imagery both activate the same area in the frontal lobe and farther back in the brain, however perception activates more areas such as the visual cortex in the occipital lobe
Trains a classifier to associate a pattern of voxel activation with particular stimuli, then present a stimulus to see if the classifier can identify It based on the pattern of voxel activity created by the stimulus
Multivoxel pattern analysis (MVAP)
What were Kosslyn’s findings regarding TMS and perception/imagery?
TMS to the visual cortex causes slower responses in both perception and imagery, concluding that activity in the visual cortex plays a role in both
Describe the case of MGS.
About to have part pf her occipital lobe removed to treat epilepsy
Pre-surgery mental walk task revealed image overflow at 15ft
Post-surgery mental walk task revealed overflow at 35ft
Reduced size of field of view
Give examples as to how problems with perception are accompanied with problems with imagery and describe what they are evidence of.
People who have lost the ability to see colour due to brain damage are also unable to create colours through imagery.
Unilateral neglect
Evidence that mental imagery and perception share the same physiological mechanisms.
Damage to the parietal lobes that causes patients to ignore objects in one half of their visual field e.g. they shave one side of their face and neglect the other.
Unilateral neglect
Describe three instances of dissociation between imagery and perception
Cecilia and Guarilia studied a patient whose brain damage didn’t really effect his ability to perceive but caused him to neglect his mental images (limited to one side)
R.M suffered damage in his occipital lobe and parietal lobes, he was able to recognize objects and draw accurate pictures of objects that were placed in front of him but was unable to draw them from memory which requires imagery. He also had trouble answering questions related to imagery.
Marlene Behrman studied C.K a 33y/o grad student who got hit by a car as he was jogging, he suffered from visual agnosia (inability to visually recognize object) he could recognize parts of the object but couldn’t integrate them into a meaningful whole.
A method in which things that need to remember are placed at different locations in a mental image of a spatial layout
Method of loci
Involves imagery but instead of visualizing items in different locations you associate them with concrete words
Pegword technique
