Chapter 10 Flashcards
visual imagery
- seeing in the absence of a visual stimulus
- easier to remember words with high imagery potential
mental imagery
experiencing a sensory impression in the absence of sensory input
imagery potential
- ease of generating an image
- high imagery potential
- low imagery potential
- recall best for high-imagery paired-associates
mental chronometry
- infer cognitive processes by measuring the time it takes to complete a cognitive task
shepard and metzler - 1971 (mental chronometry)
- measured the time to mentally rotate objects to make a verification judgment (match/no match)
- one of the first to apply quantitative methods to the study of imagery and to suggest that imagery and perception may share the same mechanisms
early ideas about imagery
- Wundt proposed that images were one of the three basic elements of consciousness, along with sensations and feelings
- Francis Galton’s (1883) observed that people who had great difficulty forming visual images were still quite capable of thinking
- Behaviorists branded the study of imagery as unproductive because visual images are invisible to everyone except the person experiencing them
imageless thought debate
the debate about whether thought is possible in the absence of images
conceptual peg hypothesis
- that states that concrete nouns create images that other words can hang on to, which enhances memory for these words
- associated with Paivios dual coding theory
mental scanning
scan a mental image with the mind
scanning - Klosslyn and Pomerantz
visual scanning time for a picture is the same for an image of that picture
images - Klosslyn
- faster to answer questions about an image when one imagines that it takes up most of their visual field
- e.g. faster to answer questions about the elephant when it’s shown next to a rabbit
perky (1910)
mistake dimly projected image as their mental image
farah (1985)
participants are faster to detect target location when the target and mental image matched
mental walk task
form a mental image of an object and to imagine that you are walking toward this mental image
imagery debate
whether imagery is based on spatial mechanisms, such as those involved in perception, or on propositional mechanisms that are related to language
spatial representation
different parts of an image can be described as corresponding to specific locations in space
depictive representations
- corresponds to spatial representation
- is so-called because a spatial representation can be depicted by a picture
epiphenomenon
- a phenomenon that accompanies a mechanism but is not actually part of the mechanism
- e.g. is lights that flash on a mainframe computer as it operates
proposition representations
relationships are represented by symbols
imagery neurons
- neurons in the visual cortex that fires when perceiving or imagining a specific object
- demonstrates a possible physiological mechanism for imagery
- these neurons respond in the same way to perceiving an object and to imagining it
le bihan et al., (1993)
- fMRI recordings reveal both perception and imagery activate the visual cortex
- asking participants to think about questions that involved imagery generated a greater response in the visual cortex than asking nonimagery questions
topographic map
indicates that viewing small objects activates the back of the visual cortex whereas larger objects result in a spread of activity toward the front of the visual cortex
do imagery and perceptions share the same mechanisms
- imagery and perception reveal similar activity in the frontal lobe
- ablation of the visual cortex results in a decrease in image size
- difficulty with perception is associated with difficulty with creating images
- those with unilateral neglect will ignore objects in one half of the visual field
do imagery and perceptions have different mechanisms
- perception is automatic and stable
- imagery takes effort and is fragile
- difficult to switch perceptions of an ambiguous image than picture
chalmers and reisberg (1985)
- difficult to switch perceptions of a mental image of an ambiguous figure
- e.g. duck or rabbit image
johnson and johnson (2014) - multivoxel pattern analysis
- used this procedure to study the relation between imagery and perception by training a classifier by presenting four different kinds of scenes—beach, desert, field, or house
- results showed the classifier predicted the correct picture on 63 percent of the trials, which is above chance accuracy
transcranial magnetic stimulation (TMS)
a procedure in which magnetic pulses are applied to the skull in order to temporarily disrupt the functioning of part of the brain
TMS - Klosslyn (1999)
- presented transcranial magnetic stimulation to the visual cortex while participants were carrying out either a perception task or an imagery task
- the results indicated that stimulation caused participants to respond more slowly, and that this slowing effect occurred both for perception and for imagery
- it was concluded that brain activity in the visual cortex plays a causal role in both perception and imagery
patient M.G.S. case study
- about to have part of her right occipital lobe removed as treatment for a severe case of epilepsy
- before the procedure M.G.S. performed the mental walk task that we described earlier and she felt she was about 15 feet from an imaginary horse before its image overflowed
- this was repeated after her right occipital lobe had been removed, the distance increased to 35 feet
- removing part of the visual cortex reduced the size of her field of view
- supports the idea that the visual cortex is important for imagery
role of parietal lobe in imagery
- unilateral neglect: the patient ignores objects in one half of the visual field
- supports the idea that mental imagery and perception share physiological mechanisms
method of loci
- mnemonic involving mental image of a spatial layout
- a method in which things to be remembered are placed at different locations in a mental image of a spatial layout
pegboard technique
- mental image of objects associated with a concrete word
- e.g. one–bun; two–shoe; three–tree; four–door; five–hive; six–sticks; seven–heaven; eight–gate; nine–mine; ten–hen
spatial imagery
the ability to image spatial relations
object imagery
the ability to image visual details, features, or objects
paper folding test (PFT)
- a test in which a piece of paper is folded and then pierced by a pencil to create a hole
- the task is to determine, from a number of alternatives, where the holes will be on the unfolded piece of paper
- designed to measure spatial imagery
vividness of visual imagery questionnaire
- a test in which people are asked to rate the vividness of mental images they create
- this test is designed to measure object imagery ability
- e.g. participants rated, on a 5-point scale, the vividness of mental images they were asked to create
degraded pictures task
- a task in which a line drawing is degraded by omitting parts of the drawing and obscuring it with a visual noise pattern
- the persons task is to identify the object
