Knowledge Representation Flashcards
Process vs. Representation
Process
- what the mind DOES, information processing such as attention and encoding
Representation
- the FORMAT of stored knowledge
- “kinds” of knowledge include declarative (based on facts) and procedural (knowledge on how to do things)
Forms of mental representation include ______ and ______
Symbolic
- abstract, arbitrary
- does not have a direct connection to what the thing is and instead uses symbols such as “5” or “five”
Analog
- concrete, direct
- can directly capture aspects of the target information
- preserves visual-spatial representations
- example is having 5 oranges or writing 5 tally marks to directly represent the concept of the number
‘Spatial’ representation
Spatial representation is the idea that visual information is represented in analog form in the mind
Kosslyn (1973)
- mental scanning task
- the farther away the verification item (plane’s tail) was from the starting point in the image (plane’s propeller), the longer it took participants to complete the task
- shows that mental images exist as spatial representations in the mind that we can access to complete a task (the task of mental scanning)
Mental Rotation (Shepard & Metzler)
- there are two objects with different orientations/rotations
- participants have to determine if the objects are identical and just in different rotational positions
- highly linear results suggest that people are creating a mental image of the object in VSSP and physically rotating it to determine if it is identical to the other object
- amount of time to determine “match” was a direct function of the degree of actual rotation
- conclusion that participants “mentally rotate” objects in the visuo-spatial sketchpad
Image scaling
- properties of mental images are often similar to real perception
- properties include size/distance relations
- analog relations between parts to whole object
Kosslyn (1975)
- imagine an elephant and a cat; property verification task asks if the cat has ears
- imagine a flea and cat; property verification task asks if the cat has claws
- participants were faster to verify details that are “larger” in the mental image; in this case it was the cat’s claws because the cat is the larger object in this cat/flea image
Image scanning
- images appear to be scanned like physical percepts
- therefore, greater distance = longer scan time
- visual image preserves spatial relations
- this is known as “spatial” representation
Kosslyn (1978)
- subjects were asked to “mentally travel” across a map of a fictional island to different locations
- the time it took to mentally travel was longer for locations that were further apart on the island
- this suggests that subjects were moving around on a spatial representation of the map in their minds
Dual-code theory (Paivio)
- TWO ways to represent concepts: VISUAL code and VERBAL code
- visual code = analog image; such as a physical image of a lamp
- verbal code = linguistic label or description; such as “the lamp is on the table”
- TWO ASSUMPTIONS OF DUAL-CODE THEORY
1. a picture will be automatically labeled with its name at the time of study
2. words will not automatically invoke a corresponding image, due to the fact that words only produce a verbal code (the word itself)
Picture superiority effect
Picture superiority effect is a result showing that memory for pictures is superior to memory for words of the same concept
- pictures produce automatic encoding in two modalities: visual code (the picture itself) AND verbal code (the label for the picture)
The concreteness effect
The concreteness effect is a result showing that memory for concrete concepts is superior to memory for abstract concepts
- although words are not automatically imagined or invoke a corresponding image, sometimes words items can be imagined during encoding or retrieval BUT concrete objects are imagined than abstract objects
Dual codes facilitates memory
- concrete concepts have BOTH codes
- richer representation of concrete concepts leads to better memory
- abstract concepts ONLY have verbal labels
- therefore, they must be represented in terms of words
- example: gravity is hard to imagine so you can only represent it through its verbal label/word form as “gravity”
Brooks (1968)
Indicate whether each word is a noun in the sentence: “John ran to the store to buy some oranges”
- this is a VERBAL stimulus
- task #1: say “yes” or “no” (verbal task)
- task #2: point to “yes” or “no”
(spatial task)
Visualize “F” and indicate whether each corner is “outside”
- this is a SPATIAL stimulus
- task #3: say “yes” or “no” (verbal task)
- task #4: point to “yes” or “no”
(spatial task)
- task #1: HARDER because subjects had to remember the sentence (verbal stimulus) and respond yes or no verbally; OVERLOAD in phonological loop
- task #2: EASIER because subjects had to remember the sentence (verbal stimulus) in the phonological loop and respond spatially by pointing to yes or no in the visuospatial sketchpad
- task #3: EASIER because subjects had to remember/visualize “F” in visuospatial sketchpad and respond verbally yes or no in phonological loop
- task #4: HARDER because subjects had to visualize “F” and point to yes or no; OVERLOAD in visuospatial sketchpad
Dual Codes in Brooks (1968)
- when the mode of responding involves the SAME CODE, performance suffers
- longer time to respond for “F” and pointing yes/no (overload in visuospatial sketchpad)
- longer time to respond for sentence and saying yes/no (overload in phonological loop)
Relational-organizational elaboration (Bower)
- imagery improves memory because it produces associations (RELATIONS) between stimuli
- more “hooks” that connect information
- specific KIND of elaboration (the development of an existing idea by incorporating new information/details to augment the idea)
Interactive imagery
- mental image of both words forms a single, interactive image
- unitization is formed when pieces of information are encoded as a single representation in memory
Bizarre imagery
The bizarreness effect is a result showing that memory for unusual images is superior to memory for typical images
- bizarre sentences that create an unusual image were remembered better than sentences that create a more common, logical image
- bizarreness effect is caused by the distinctiveness of the bizarre image when compared with the common image
- so, bizarre sentences are less distinct when all of the sentences to be remembered are bizarre
- bizarre imagery only aids memory when it stands out against other studied information
- remember: DISTINCTIVENESS aids/improves memory
Functional equivalence between imagery and perception (are they the same thing?)
- similar phenomena in mental visualization as in visual perception LIKE rotation and scanning
- imagery can PRIME visual perception
- for example, in the geon experiment, seeing the same kind of piano again allows you to recognize it faster
- imagery leads to activation in the primary visual cortex
- BUT images must be maintained as a whole in the VSSP in WORKING MEMORY, meaning that you must give it attention
- AND imagery is subject to bias, selection, distortion
- varying interpretation of ambiguous images
- perceptual details of images are lost
Propositional representations
Propositional representation is the idea that visual information is represented nonspatially in the mind
- idea that all information is stored as “propositions”
- captures concepts and their relationships
Pylyshyn (1973)
- abstract “language of thought”
- for example, for the sentence “The boy flew his kite,” you know that the boy is the subject of the sentence, flew is the verb, and his kite is the object of the verb; Knowing the purpose of each of these parts allows you to interpret the sentence and understand the ideas presented in it
- propositional representation is retrieved THEN the image or verbal code is re-created/translated
- this implies that imagery is “epiphenomenal” or has no effects or causes anything?
Cognitive maps (large-scale environments)
- specialized representations of large-scale physical environment
Landmark knowledge
- learn or rely on salient landmarks in order to orient yourself around that specific environment
- Northwestern example: the Arch
Route knowledge
- begin to link landmarks together which leads to a route; showcases how to get from point A to point B
- Northwestern example: Evanston to Chicago
Survey knowledge
- top down view; relationship between routes and how they fit together; requires direct experience to determine how point A connects to point B, C, D, etc even though you have not taken all routes like anything after point B
Distortions based on conceptual knowledge: Tversky (1981) alignment & rotation heuristics
- conceptual knowledge (schemas) can distort large-scale spatial representations; especially through simplication
- alignment heuristic: people tend to align 2+ objects on a common vertical or horizontal axis more than they should be
- rotation heuristic: people tend to rotate an object so it is better aligned with vertical or horizontal
- example: for our cognitive map of California, we make the orientation more vertical by rotating the coastline in a clockwise fashion
Distortions based on conceptual knowledge: Thorndyke (1981)
- route knowledge can distort representations of space and distance
- participants asked to memorize maps with 4 cities
- then participants estimated the distance between the cities
- “longer” perceived distance between cities as more cities were along the route
Comprehension
