8 Flashcards
(36 cards)
imagery
mental representation of a perceptual experience (usually visual, but other modalites are possible). modality specific, retaining perceptual features of physical stimulus they represent. introspective and cannot be verified by others
symbolic representation
arbitrary representation of a concept, often stored as language, can be schematic, can be abstract concept knowldge. does not resemble real world referent
paivio’s dual-code theory
thoughts can be represented in symbolic code (words), or as analogue code (images)
examples of symbolic code that does resemble real world referent
onomatopoeia, but this is an exception, not the rule
can all knowledge be analogue? how about symbolic
some things can be analogue. things like the feeling of pain when you realize you forgot a prop at home when you arrive at con are hard to represent in analogue. everything can be put in symbolic code
kosslyn’s functional equivalence hypothesis
analogue codes represent all info. depective perspective. perceptual and spatial characteristics maintained. kinda like an earlier version of embodied approach
pylyshyn’s propositional theory
images are epiphenomena of underlying propositional networks, images are stored as propositions. descriptive perspective.
propositions
smallest idea unit that can be verified as true/false. order of propositions in speech does not matter. strictly mental. cannot be physical. language is a tool to tell propositions
is it possible that mental images do not exist at all? are they the most fundamental unit of mental representation?
no, we can form images, however, images may not be the most fundamental unit of mental representation
what does mental scanning show about knowledge representations
images are analog code of physical stimuli, and therefore it should take longer to process larger mental distances than shorter ones. this was confirmed experimentally
results of mental rotation experiment by shepard and metzler
if shape matches target, the greater the rotation angle, the longer it takes to match. if the shape is different than target, all rotation angles take the same amount of time
image scanning experiment procedure
memorize a map with various landmarks of differing distances. imagine you are at the beach. mentally scan the map until you get to the windmill/lighthouse.
image scanning experiment results
takes longer to mentally scan a larger distance
issues raised about the image scanning experiment
experimentor expectancy (unconsciously tell participants what they expect results to be), demand characeteristics (subtle clues in experimental tasks/instructions; not from experimentor bias, may bias behavior). participants acted as if they were supposed to travel around because scanning a map is not natural. if people were asked to visualize light, where the light comes from doesn’t matter for how fast it takes to see the light
image scaling experiment procedure and results
if one visualizes large objects, they see small details more easily. initially used rabits, flies, elephants, etc. experimentors worried the response time was related to previous relationships with animals, so they changed it to “elephant sized rabbit” and “rabbit-sized elephant”
perceptual interference experiment procedure and results
people were told to imagine a visual or auditory stimuli, then told to detect a real stimuli that is either auditory or visual. if the target is the same modality as visual stimuli, then the detection rate will be slow. this is because visual stimuli used up some processing mechanisms
single modality perceptual interference test procedure and results
participants imagine the letters T of H. you will then be more accurate at detecting the same letter imagined, compared to the other letter
how do fMRI studies provide support for functional equivalence theory
imagery and perception share similar active areas but can be distinguished by magnitude of fMRI activity. nonvisual areas are deactivated during imagery because imagery is fragile (to prevent interference)
when might you mistake perception as imagery?
perky’s experiment where you imagine a book, then project a very dim image of a specific book in front of person. person will describe mental image as the book displayed by projector in front of them
evidence against functional equivalence hypotheses
reed’s study where person is shown ambiguous figure, and then asked if a parallelogram that was hard to see was in the image. people tended to not see it. if imagery stored the stimuli, then you should be able to see it. reed says the image was likely stored as a verbal description (two overlapping triangles) and the description does not contain the term “parallelogram” so you don’t see it
does evidence suggest we form mental images analogous to real objects? can we also use propositions
yes to both
when do we form propositions
relatively complex objects, and/or objects that require us to assign meaning to percept.
picture superiority effect
if an image is formed, we are more likely to retrieve it, because there are two copies in memory
aside from interactive images and picture superiority, why else would images help improve LTM
concreteness effect; concrete things tend to be spontaneously visualized, and now you have 2 codes
