Chapter 9: Conceptual Knowledge Flashcards
Conceptual Knowledge
knowledge that enables people to recognize objects and events and to make inferences about their properties
Concepts
a mental representation of a class or individual, also, the meaning of objects, events, and abstract ideas
an example of a concept would be the way a person mentally represents “cat” or “house”
Category
groups of objects that belong together because they belong to the same class of objects, such as “houses”, “furniture”, or “schools”
Categorization
the process by which objects are placed in categories
Differential Approach to Categorization?
the idea that we can decide whether something is a member of a category by determining whether the object meets the definition of the category
Family Resemblance
in considering the process of categorization, the idea that things in a particular category resemble each other in a number of ways
this approach can be contrasted with states that an object belongs to a category only when it meets a definite set of criteria
Prototype Approach to Categorization
the idea that we decide whether something is a member of a category by determining whether it is similar to a standard representation of the category, called a prototype
Prototype
a standard use in categorization that is formed by averaging the category members a person has encountered in the past
Sentence Variation Technique
a technique in which the participant is asked to indicate whether a particular sentence is true or false
for example, sentences like “an apple is a fruit” have been used in studies on categorization
Typicality Effect
the ability to judge the truth or falsity of sentences involving high-prototypical members of a category more rapidly than sentences involving low-prototypical members of a category
Exemplar Approach to Categorization
the approach to categorization in which members of a category are judged against exemplars, which are examples of members of the category that the person has encountered in the past
Exemplars
in categorization, members of a category that a person has experienced in the past
Hierarchical Organization
organization of categories in which longer, more general categories are divided into smaller, more specific categories
these smaller categories can, in turn, be divided into even more specific categories to create a number of levels
Superordinate Level
the most general category level distinguished by Rosch
for example; “furniture”
Global Level
the highest level in Rosch’s organization scheme (e.g. “furniture” or “vehicles”)
Basic Level
in Rosch’s categorization scheme, the level below the global level
according to Rosch, the basic level is psychologically special because it is the level above which much information is lost and below which little is gained
Subordinate Level
the most specific category level distinguished by Rosch
e.g. “kitchen table”
Specific Level
in Rosch’s categorization scheme, the level below the basic level
Semantic Approach
an approach to understanding how concepts are organized in the mind that proposes that concepts are arranged in networks
Hierarchical Model
as applied to knowledge representation, a model that consists of levels arranged so that more specific concepts, such as canary or salmon, are at the bottom and more general concepts, such as bird, fish, or animal are at higher levels
Cognitive Economy
a feature of some semantic network models in which properties of a category that are shared by many members of a category are stored at a higher-level node in the network
for example, the property “can fly” would be stored at the node for “bird” rather than “canary”
Spreading Activation
activity that spreads out along any link in a semantic network that is connected to an activated node
Lexical Decision Task
a procedure in which a person is asked to decide as quickly as possible whether a particular stimulus is a word or a nonword
Connectionism
a network model of mental operation that proposes that concepts are represented in networks that are modeled after neural network
this approach to describing the mental representation of concepts is also called the parallel distributed processing (PDDP) approach
Connectionist Network
the type of network proposed by the connectionist approach to the presentation of concepts
connectionist networks are based on neural networks but are not necessarily identical to them
one of the key properties of a connectionist network is that a specific category is represented by activity that is distributed over many units in the network
this contrasts semantic networks, in which specific categories are represented at individual nodes
Units
“neuron-like processing units” in a connectionist network
Input Units
units in a connectionist network that are activated by stimulation from the environment
Hidden Units
units in a connectionist network that are located between input units and output units
Output Units
units in a connectionist network that contain the final output of the network
Connection Weight
in connectionist models, a connection weight determines the degree to which signals sent from one unit either increase or decrease the activity of the next unit
Error Signal
during learning in a connectionist network, the difference between the output signal generated by a particular stimulus and the output that actually represents that stimulus
Back Propagation
a process by which learning can occur in a connectionist network, in which an error signal is transmitted backward through the network
this backward-transmitted error signal provides the information needed to adjust the weights in the network to achieve the correct output signal for a stimulus
Graceful Degradation
disruption of performance due to damage to a system that occurs only gradually as parts of the system are damaged
this occurs in some cases of brain damage and also when parts of a connectionist network are damaged
Category-Specific Memory Impairment
a result of brain damage in which the patient has trouble recognizing objects in a specific category
Sensory-Functional (S-F) Hypothesis
explanation of how semantic information is represented in the brain that states that the ability to differentiate living things and artifacts depends on one system that distinguishes sensory attributes and another system that distinguishes function
Multiple-Factor Approach
seeking to describe how concepts are represented in the brain by searching for multiple factors that determine how concepts are divided up within a category
Crowding
animals tend to share many properties, such as eyes, legs, and the ability to move
this is relevant to the multiple-factor approach to the representation of concepts in the brain
Semantic Category Approach
an approach to describing how semantic information is represented in the brain that proposes that there are specific neural circuits for some specific categories
Embodied Approach
proposal that our knowledge of concepts is based on reactivation of sensory and motor processes that occur when er interact with an object
Semantic Somatotopy
correspondence between words related to specific parts of the body and location of brain activity associated with that part of the body
Semantic Dementia
condition in which there is a general loss of knowledge for all concepts
Anterior Temporal Lobe (ATL)
area in the temporal lobe, damage to the ATL has been connected with semantic deficits in dementia patients and with the savant syndrome
Hub and Spoke Model
a model of semantic knowledge that proposes that are associated with different functions are connected to the anterior temporal love, which integrates information from these areas
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
What is conceptual knowledge?
knowledge that enables us to recognize objects and events and to make inferences about their properties
What are concepts?
mental representation used for a variety of cognitive functions
What is categorization?
the process by which things are placed into groups called categories
categories are all possible examples of a particular concept
Why are categories useful?
help to understand individual cases not previously encountered
“pointers to knowledge”
categories provide a wealth of general information abut an item
allow us to identify the special characteristics of a particular item
What is the definitional approach to categorization?
determine category membership based on whether the object meets the definition of the category
does not work well
not all members of everyday categories have the same defining features
family resemblance proposed to deal with the problem of definition
What is family resemblance?
things in a category resemble one another in a number of ways
What is the process of determining categories by similarity?
compare object to a “standard”
prototype approach: the standard is determined by averaging category members
exemplar approach: the standard is created by considering a number of typical members of a category
What is the prototype approach?
prototype = “typical”
an average representation of the “typical” member of a category
characteristic features that describe what members of that concept are like
an average of category members encountered in the past
What is high-prototypicality?
category member closely resembles category prototype
“typical member”
What is low-prototypicality?
category member does not closely resemble category prototype
What is the relationship between prototypicality and family resemblance?
strong positive relationship
when items have a large amount of overlap with characteristics of other items in the category, the family resemblance of these items is high
low overlap = low family resemblance
What is the typicality effect?
prototypical objects are processed preferentially
highly prototypical objects judged more rapidly
What is the exemplar approach?
recall: goal is to compare an object to a “standard”
“standard” = exemplar
actual category members a person has encountered before
concept is represented by multiple examples (rather than a single prototype)
examples are actual category members (not abstract averages)
to categorize, compare the new item to stored examples
the more similar a specific exemplar is to a known category member, the faster it will be categorized
In what ways is the exemplar approach the same and different compared to the prototype view?
similar: representing a category is not defining it
different: representation is not abstract, descriptions of specific examples
What is hierarchical organization?
larger, more general categories are divided into smaller, more specific, categories to create a number of levels of categories
What is the evidence that basic level is special?
going above basic level results in a large loss of information
going below basic levels results in little gain of information
What are semantic networks?
conecpts are arranged in networks that represent the way concepts are organized in the mind
node = category/concept
concepts are linked
model for how concepts and properties are associated in the mind
What is cognitive economy?
shared properties are only stored at higher-level nodes
exceptions are stored at lower nodes
What is inheritance?
lower-level items share properties of higher-level items
What is spreading activation?
activation is the arousal level of a node
when a node is activated, activity spreads out along all connected links
concepts that receive activation are primed and more easily accessed from memory
What is the lexical decision task?
participants read stimuli and are asked to say as quickly as possible whether the item is a word or not
What are the criticisms of semantic networks?
cannot explain typicality effects
cognitive economy
some sentence-verification results are problematic for the model
What is the connectionist approach?
creating computer models for representing cognitive processes
parallel distributed processing
knowledge represented in the distributed activity of many units
weight determine at each connection how strongly an incoming signal will activate the next unit
What are input units?
activated by stimulation from environment
What are hidden units?
receive input from input units
What are output units?
receive input from hidden units
How does learning occur in the connectionist approach?
network responds to stimulus
provided with correct response
modifies responding to match correct response
What is an error signal?
difference between actual activity of each output unit and the correct activity
What is back-propagation?
error signal transmitted back through the circuit
indicates how weights should be changed to allow the output signal to match the correct signal
the process repeats until the error signal is zero
What is graceful degradation?
disruption of performance occurs gradually as parts of the system are damaged
What are the different categories in the brain for knowledge?
different areas of the brain may be specialized to process information about different categories
double dissociation for categories “living things” and “nonliving things”
category-specific memory impairment
What is the multiple factors approach?
looks at how concepts are divided up within a category rather than identifying specific brain areas of networks for different concepts
What is crowding?
when different concepts within a category share many properties
What is the embodied approach to categories in the brain?
our knowledge of concepts is based on reactivation of sensory and motor processes that occur when we interact with the object
What are mirror neurons?
neurons that fire when we do a task or when we observe another doing that same task
What is semantic somatotopy?
correspondence bewteen words related to specific body parts and the location of brain activation
