Conceptual Knowledge (CH 9) Flashcards
What is Conceptual Knowledge?
- Knowledge that enables us to recognize objects & events & to make inferences about their properties
- Exists in the form of concepts
What are Concepts?
- Mental representation of class or individual
- Categories of objects, events, & abstract ideas
- Provides the rules for creating categories
How do we organize Concepts?
-In terms of Categories
What is a Category?
- Includes all possible examples of a particular concept
- Pointers to knowledge
- Helps us understand behaviors
What is Categorization?
- Process by which things are placed in categories
- Helps us understand what is happening in the environment & plays role in helping us take action
- It becomes more difficult when we encounter something unfamiliar
What approach of categorization does not work?
-The Definitional approach bc it doesn’t work well for natural objects (birds, trees) & human-made objects (chairs)
What is the basis of Definitional Approach to Categorization?
- We can decide whether something is a member of a category by determining whether a particular object meets the definition of the category
- This approach works well for geometric shapes
What is Family Resemblance?
- Proposed by Wittgenstein to solve the problems of definitions not including all members of a category
- Refers to the idea that things in a particular category resemble one another in a number of ways= allows for more variation
What is the Prototype approach to Categorization?
-Membership in a category is determined by comparing the object to a prototype that represents the category
What is a Prototype?
-A typical member of the category= AVERAGE representation of a category (NOT actual member of category)
What is Typicality?
- Variations within categories
- Can be Low or High typicality
What is High Typicality?
-The category member CLOSELY resembles the category prototype (like a typical member of the category)
What is Low Typicality?
-The category member DOES NOT closely resemble a typical member of the category
How do we determine a good example for a category?
-When an object shares MANY attributes with other members of its category
What is the Sentence Verification Technique?
- It’s used to determine how rapidly people could answer questions about an object’s category
- Participants are presented w/ various statements & agree whether that the statement is true or not
- Concluded that particpants responded faster to for objects that are high in prototypicality (apple is a fruit vs pomagranate is a fruit)
What is the Typicality Effect?
-Ability to judge highly prototypical objects more rapidly (apple is a fruit= faster response than pomegranate is a fruit)
How does Priming occur?
-When the presentation of a stimulus facilitates the response of a stimulus that following closely behind the first one
What is the Exemplar Approach to Categorization?
- It involves determining whether an object is similar to other objects but involves MANY examples= exemplar
- Explains the typicality effect by proposing that objects that are more like the exemplars are classified faster
What are Exemplars?
-Actual members of the category that a person has encountered in the past
(labs, pugs, & boxers as exemplars for dogs)
What are the advantages of the Exemplar Approach to Categorization?
- Uses real examples= can easily take into account atypical cases= doesn’t discard info that may be useful later
- Can deal with more variable categories like games
How might we use both the Exemplar Approach & the Prototype Approach to Categorization?
- When we initially learn about a category, we may average exemplars into a prototype & as we continue to learn, some of the exemplar info becomes stronger
- Early in learning we would be poor at taking into account “exceptions” to a category (penguins/ ostriches)
What is Hierarchical Organization?
-When larger, more general categories are divided into smaller, more specific categories= creating levels & number of categories
What are the 3 different levels of categories?
Superordinate/ Global Level (furniture)= has 3 common features
Basic level/ reflects everyday experience (table)= has 9 common features
Subordinate/Specific level (kitchen table)= has 10.3 common features
How can knowledge affect categorization?
- People with more knowledge about certain objects tend to focus on more specific info about the objects
- Categorization is learned from experience and the objects that we typically encounter & what characteristics of these objects we pay attention to
What is the Semantic Network Approach?
- Proposes that concepts are arranged in networks
- It is a hierarchical model bc it consists of levels arranged so that more specific concepts (canary) are at the bottom & general concepts are at higher levels (bird–> animal–>living thing)
What is Cognitive Economy?
-Efficient way of storing shared properties just once in the higher level node in the Semantic Network Approach
(Feathers or can fly won’t have its individual node bc most birds have these characteristics & it takes up too much space)
-When an object has an exception then it would be indicated
What does Collins & Quillian’s hierarchial semantic network diagram indicate?
- How concepts & their properties are associated in the MIND (not physiologically)
- How we retrieve properties associated w/ a concept
What are the predictions that the Hierarchial Semantic Network Diagram can make?
-The time it takes for a person to retrieve info about a concept should be determined by the distance that must be traveled through the network (canary–>bird is faster than canary–>animal)
What is Spreading Activation?
- Is activity that spreads out along any link that is connected to an activated node & can also spread to other nodes in the network
- The result is those additional concepts that receive this activation become “primed”= easily retrieve info from memory
What was the Lexical Decision Task about?
- Participants were tasked w/ reading a pair of stimuli from 4 different groups. If both the words were real they answered “yes” if one of the words wasn’t real they would answer “no”
- Results showed that reaction time was faster when the 2 words were associated= retrieving one word from memory created this domino effect where activation would spread to other locations in the network
What does collin’s & Quillian hierarchial network model fail to explain?
-The typicality effect (reaction times about an object is faster for a typical member)
What is Connectionism?
- An approach to creating computer models for representing cognitive processes
- It is inspired by how info is represented in the brain
- Can explain hella findings including how concepts are learned & how brain damage affects people’s knowledge about concepts
What is Parallel Distributed Processing (PDP)?
- Propose concepts are represented by an activity that is distributed across a network
- Consist of (bottom to top) Input units–>Hidden Units–> Output Units w/ connecing lines in between the 3 layers of units
- The darker the connecting lines & the circle (units)= more activity
- Also have Connection Weights
Describe the Parallel Distributed Processing (PDP)
- The circles (units) are inspired by the neurons in the brain
- Units that are activated by stimuli from the enviornment= Input units, these units send signals to Hidden Units & then to the Output Units
- The lines are connections that transfer info between units ( kind equivalent to axons)
- Have Connection Weights= determines how signals sent from one unit increase OR decrease the activity the activity of the next unit (corresponds to what happens at a synapse that transmits signals from one neuron to another)
What are the different types of Connection Weights in the PDP?
- High connection weights= strong tendency to excite the next unit
- Lower connection weights= less excitation
- Negative weights= decrease excitation or inhibit activation of the recieving unit
What do the Activation Units in a network depend on in the PDP?
- The signal that originates in the input units
- The connection weights throughout the network
What is responsible for the basic principle of Connectionism?
-Differences in activation & pattern of activity that they create
What is the basic principle of Connectionism?
-A stimulus presented to the input units is represented by the pattern of activiy that is distributed across other units
What is a Connectionist Network?
- Are similar to the hierarchial semantic network but conncetionist network indicate properties by activity units on the far right & by the pattern of activity in the representation & hidden units in the middle of the network
- Is more similar to what happens in the brain/ can simulate the cognitive processes
- The operation IS NOT totally disrupted by damage
- Can explain generalization of learning (similar concepts have similar patterns= enables us predict properties of different objects we’ve never seen)
How is a concept represented in a Connectionist network?
-By the pattern of activity in all of the units in the network
How is the answer to “A canary can” represented in a Conncectionist network?
- By activation of the property units plus the activation of the network’s representation and hidden units
- BUT the network MUST BE TRAINED in order to achieve this result
How might an untrained Conncetionist network function?
-Stimulating the “canary” & “can” units sends activity out to the rest of the network, the effect of this activation depnds on the connection weights between units
How would a connectionist network operate properly?
- The connection weights have to be adjusted so that activating the concept unit “canary” and the relation unit “can” activates only the property units “sing, move, fly, grow”
- The adjustments of weights are achieved via Learning Process
What is the Learning Process of connection weights in connectionist networks?
- Occurs when erroneous reponses in the property units cause an Error Signal to be sent back through the network= Back Propagation (error signals are sent back to property units)
- Once back to hidden units & representation units, they provide info about how connection weights should be adjusted so that the correct property units become activated
How are Connectionist networks created?
-By a learning process that shapes the networks so information about each concept is contained in the distributed pattern of activity across a number of units
What is Graceful Degradation?
-Disruption of performance occurs only gradually as parts of the system are damaged (similar to partial loss of functioning when someone has brain damage)
What are the 4 physiological approaches to how concepts are represented in the brain?
- Sensory Functional Hypothesis
- Multiple Factor Approach
- Semantic Category Approach
- The Embodied Approach
What are the 2 network Approaches to categorization?
- Semantic Networks (collin & quillian)
- Connectionism
What are the 4 Behavioral Approaches to categorization?
- Definitional Approach
- Prototype
- Exemplar
- Hierarchial Organization
What is Category-specific memory impairment?
-Impairment in which the ability to identify one type of object is lost but could still identify other objects
What is Sensory Functional (S-F) Hypothesis?
- States that our ability to to differentiate living things & artifacts depends on a memory system that distinguishes sensory attributes & a systems that distinguishes function
- Agrees that artifacts are a HOMOGENEOUS category
What is the Multiple-Factor approach?
- Emphasizes role of many different features & properties
- Rsearch shows that some mechanical devices (musical instrument) in the middle ground between artifacts (perfomed actions) & living things (sound & motion)
What is Crowding?
- Another factor to differentiate animals & artifacts
- Refers to the fact that animals tend to share many properties vs Artifacts share fewer properties
Based on the idea of Crowding, what is proposed about patients that have category-specific impairments?
-That these patients don’t really have an impairment at all because they actually have difficulty distinguishing between items that share similar features (animals sharing more features= difficulty recognizing animals)
What is the Semantic-Category Approach?
- Proposes that there are specific neural circuits in the brain for some specific categories/stimuli
- Emphasizes that the brain’s response to items from a particular category is distributed across different cortical areas
- Comes into play when we look at a scene & when we listen to someone who’s talking
What categories does Understanding Language involve?
- Concrete categories (living things, foods, places)
- Abstract concepts (feelings, values, thoughts)
What is the Embodied Approach?
-States that our knowledge of concepts is based on reactivation of sensory & motor processes that occur when we interact with the object
(when we use a hammer, sensory areas are activated for size, shape color & motor areas are activated when carrying out actions involved in using a hammer)
What is central to the Embodied Approach?
-The link of perception (neurons firing when experimenter picks up food) w/ motor responses (same neurons when monkey picks up food) in Mirror Neurons
What is Semantic Somatotopy?
-Correspondance between words related to specific parts of the body & location of the brain activity
(action of kicking & reading the word kick elicited responses from the same area of the brain)
What are the criticisms revolving the Embodied Approach?
- That the ability to represent motor activity associated with actions is not necessary for recognizing objects
- It isn’t well suited to explaining our knowledge of abstract concepts (democracy/truth)
What is Semantic Category-Specific Approach?
-Emphasizes specialized areas of the brain & networks connecting these areas
What do all the Physiological approaches have in common?
-The info about the concepts is distributed across many structures of the brain (of course each one emphasizes on different types of info)
What is Semantic Dementia?
-Causes general loss of knowledge for all concepts
(patients tend to be equally deficient in identifying living things & artifacts)
-Anterior Temporal Lobe (ATL) is damaged
What is the Hub & Spoke model of semantic knowlege?
-States that areas of the brain that are associated w/ specific functions are connectioned to the Anterior Temporal Lobe (ATL) which serves as a hub that integrates info from these areas (functions= Valence/weak vs strong, auditory, speech, praxis/involving manipulation, functionality, visual)
What happens when there is damage to the Spoke vs The Hub?
- Damage to the Spoke (one of specialized brain areas)= Specific deficits= recognizing artifacts
- Damage to the Hub (ATL)= general deficits= semantic demential
What does the Transcranial Magnetic Stimulation (TMS) cause?
-Temporary disruption of the function of one particular area of the brain by applying a pulsating magentic field using a stimulating coil placed over the person’s skull
