Visual Knowledge and Imagery

Question 1

mental imagery

Answer 1

experienceing a sensory impression in the absence of sensory input

Question 2

visual imagery

Answer 2

seeing in the absence of visual stimulus

Question 3

how is visual imagery useful

Answer 3

provides a way of thinking that adds another dimension to purely verbal techniques
can imagine with other sense too
-auditory
-smell
-taste
-tactile experiences

Question 4

imagery and the cognitive revolution

Answer 4

developed ways to measure behaviour that could be used to infer cognitive processes
paired-associate learning

Question 5

paivio cognitive revolution and imagery

Answer 5

paivio

-memory for words that evoke mental images (concrete nouns) is better than those that do not (abstract nouns)

Question 6

shepard and meltzer, imagery and the cognitive revolution

Answer 6

mental chronometry
participants mentally rotated one object to see if it matched another object
one of the first quentitative studies of imagery
suggested imagery and perception may share the same mechanisms
mental rotation task - the further the distance, the longer it takes. seen in both rotation in depth and plane

Question 7

mental scanning

Answer 7

spatial correspondence between imagery and perception

Question 8

scanning and acuity

Answer 8

we act as if our mental images are physical entities
scannin like kosslyns boat
acuity like elephat / rabbit / fly experiment

Question 9

kosslyn’s boat

Answer 9

memorize picture, create an image of it
in image move from one part of the picture to another eg anchor to cabin
it took longer for participants to metnally move long distances than shorter distances
conc like perception, imagery is spatial

Question 10

lea explanation of scanning results

Answer 10

more distraction when scanning longer distance may have increased reaction time
demo - scanning california maybe listen for conclusions

Question 11

kosslyn et al’s islands

Answer 11

island with 7 locations, 21 possible trips
it took longer to scan between greater distances
conc - visual imagery is spatial, even when distractions are equated

Question 12

is imagery spatial or propositional

pylyshyn

Answer 12

spatial representation is an epiphenomenon
-accompanies real mechanism but is not actually part of it = external lights flashing on a computer
proposed that imagery is propositional - can be represented by abstract signals and language

Question 13

how does Pylyshyn explain kossylns boat

Answer 13

tacit-knowledge explanation
suggests people use real-world knowledge unconsciously and it influences imagery
eg we know it takes longer to drive bigger distances

Question 14

finke and pinker view of is imagery spatial or positional

Answer 14

participant judge whether arrow points to dots previously seen
longer reaction time when greater distance between arrow and dot (as if they were mentally throwing)
not instructed to use visual imagery
no time to memorize, no tacit knowledge

Question 15

comparing imagery and perception

Answer 15

relationship between viewing distance and ability to perceive details
-imagine small animal next to larger animal
-quicker to detec details on the larger animal
faster to answer question about whiskers on the rabit when comapred to a fly than an elephant

Question 16

mental-walk task

Answer 16

how close can you get to your image until it overflows your visual field?
move closer to small animals than to large animals
images are spatial, like perception

Question 17

perky study looking at interactions of imageyr and perception

Answer 17

project mental image onto screen
very dim (below conscious level picture
-particiaptns likely to confuse actual picutre and their mental image

Question 18

farah study looking at interactions of imagery and perception

Answer 18

imagery affected perceptual task
letter visualisatoin experiment
participant visualises H or T on the screen
then flash A
then letter flashed on either left or right side of screen
participant has to determin whether the test letter was flashed in the first or second square
results = accuracy was higher when the letter was the same as the one that had been imagined

Question 19

category specific neurons

Answer 19

imagery neurons respond to both perceving and imaging an object
-located in medial temporal lobe
same response of neuron to both imagery and perception

Question 20

leBihan et al brain activation

Answer 20

overlap in brain activation for perception and imagery in visual cortex
complex overlap of activation
differences near back of the brain

Question 21

amedi and coworkers also looking at imagery and perception

Answer 21

again overlap
deactivation of non-visual areas of the brain
-hearing
-touch
mental images are more fragile, less activation keeps other things from interfereing

Question 22

brain activity in response to imagery

Answer 22

may indicate something is happening
may not cause imagery
how to prove a causal mechanism?

Question 23

transcranial magnetic stimulation

Answer 23

decreases brain functioning in parituclar area of the brain for a short time
if behaviour is disrupted the deactivated part of the brain is causing that behaviour
(another way to explore is to use neurocortical legions)

Question 24

kosslyn and TMS

Answer 24

TMS to visual area of brain during eprception and imagery task
response time slower for both
brain activity in visual area of brain plays a causal role for both perception and imagery

Question 25

patient MGS

Answer 25

had a portion of her right occipital lobe removed as a treatment for epilepsy
farah et al measured her performance on the mental walk task before and after surgery
after surgery the size of her visual field was reduced and she could mentally approach only to wihtin 35 feet (before was 15)

Question 26

unilateral neglect

Answer 26

patient ignores objects in one half of visual field in perception and imagery the italian street
neglect pattern occurs for metnal images the same way it does for visual perception

Question 27

guariglia and coworkers on imagery and perception damages

Answer 27

brain damaged patient
patients perceptions intact but mental images were impaired (italian street task)
dissociation between imagery and perception instead of the overlap seen before

Question 28

patient RM

Answer 28

perception intact, imagery impaired
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

Question 29

patient CK

Answer 29

imagery intact, perception impaired
inability to name pictures of objects, even his own drawings, in front of him
could draw objects in great detail from memory (using imagery)

Question 30

making sense of neuropsychological results

Answer 30

evidence for double dissociation between imagery and perception
- indicates separate mechanisms
also evidence for shared mechanisms - shared deficits in many patients
how can both findings be explained?

Question 31

behrmann and coworkers on making sense of neuropsychological results

Answer 31

mechanisms still partially overlap
visual perception involved bottom-up processing located at lower and higher visual centres
imagery is a top down process; located at higher visual centres
explains ck and rm but not mgs
These locations can explain why C.K. has a perceptual problem but can still create images, and why R.M. has trouble creating images but can still perceive.
so actual object to receiving area to higher visual areas to memory storage
perception is the bottom up arrow and imagery is the top down

Question 32

differences in experience

Answer 32

perception is automatic and stable

imagery takes effort and is fragile

Question 33

chalmers and reisberg

Answer 33

had participants create mental images of ambigious figures

difficult to flip form one perception to another wile holding a mentla image of it

Question 34

eidetic imagery

Answer 34

photographic memory
extremely rare
found in some autistic individuals
more common in kids than adults

Question 35

what is an epiphenomenon

Answer 35

something that goes along with a process but isnt really part of it