Cognitive Psychology: Chapter 9
The ______ model includes associations between concepts and the property of spreading activation.
semantic network
Which of the following statements is NOT cited in your text as a reason why categories are useful?
Categories provide definitions of groups of related objects.
Advantages of the Connectionist Approach
Concepts are represented by distributed network activity Connection weights can be excitatory or inhibitory Networks can be trained! Back propagation sends error signals backward through the network, which adjusts connection weights After many repetitions, network can "learn" and "generalize"! Networks show graceful degradation
Semantic Somatotpoy
Correspondence between words related to specific parts of the body and the location of brain activity associated with that part of the body.
Conceptual Knowledge
Knowledge that enables people to recognize objects and events and to make inferences about their properties.
Are basic - level categories special
Naming things demonstration -The first name you come up with is basic-level categories 1. Global (Furniture) 2. Basic (Table) -Basic categories appear to be psychologically privileged -Basic gives just enough information: For each person your basic names will be influenced by experience and expertise 3. Specific (Kitchen Taste)
Mirror Neurons
Neurons in the premotor cortex, originally discovered in the monkey, that respond both when a monkey observes someone else (usually the experiment) carrying out an action and when the monkey itself carries out the action. There is also evidence for mirror neurons in humans.
Hierarchical Organization
Organization of categories in which larger, more general categories are divided into smaller, more specific categories. These categories can, in turn, be divided into even more specific categories to create a number of levels.
Which of the following is a connectionist model proposing that concepts are represented by activity that is spread across a network?
Parallel distributed processing theory
Naming
People are more likely to list some objects than others when asked to name objects in a category. -Experimental Result: -High-prototypical items are name first when people list examples of a category (Mervis)
Typicality Effect
People react rapidly to members of a category that are "typical" of the category. -Experimental Result: -Faster reaction time to statements like "A_is a bird" for high-prototypical items (like robin) than for low prototypical items (like ostrich) (Smith)
Priming
Presentation of one stimulus affects responses to a stimulus that follows. -Experimental Result: -Faster same-different color judgments for high prototypical items (Rosch) Conceptual/semantic priming due to spreading activation
Embodied Approach
Proposal that our knowledge of concepts is based on reactivation of sensory and motor processes that occur when we interact with an object.
Which approach to categorization involves forming a standard representation based on an average of category members that a person has encountered in the past?
Prototype
Parallel Distributed Processing (PDP)
See connectionism and connectionist network
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.
Where is knowledge in LTM in the hierarchy?
Semantic (meaning)
Smith and Medlin 1981
Without concepts and categories, mental life would be chaotic.
Learning takes place in a connectionist network through a process of ______ in which an error signal is transmitted starting from the property units.
back propagation
The prototype approach to categorization states that a standard representation of a category is based on
category members that have been encountered in the past.
Learning in the connectionist network is represented by adjustments to network
connection weights.
One of the key properties of the _____ approach is that a specific concept is represented by activity that is distributed over many units in the network.
connectionist
One beneficial property of connectionist networks is graceful degradation, which refers to the property that
damage to the system does not completely disrupt its operation.
Not all of the members of everyday categories have the same features. Most fish have gills, fins, and scales. Sharks lack the feature of scales, yet they are still categorized as fish. This poses a problem for the approach to categorization.
definitional
The definitional approach to categorization
doesn't work well for most natural objects like birds, trees, and plants.
If you say that "a Labrador retriever is my idea of a typical dog," you would be using the approach to categorization.
exemplar
Research suggests that the ______ approach to categorization works best for small categories (e.g., U.S. presidents).
exemplar
Priming occurs when presentation of one stimulus
facilitates the response to another stimulus that usually follows closely in time.
Imagine that a young child is just learning about the category "dog." Thus far, she has experienced only two dogs, one a small poodle and the other a large German shepherd. On her third encounter with a dog, she will be LEAST likely to correctly categorize the animal as a dog if that animal
is a dog that does not bark.
Olin and Bob are neighbors. Olin loves birds and his father works for the zoo. He has been to a dozen bird sanctuaries, and he and his dad go on bird watching hikes once a month. In contrast, Bob doesn't think much about birds. His only contact with them is in his backyard. It would be correct to say that Olin's standard probably involves
more exemplars than Bob's.
Spreading activation
primes associated concepts.
Rosch found that participants respond more rapidly in a same-different task when presented with "good" examples of colors such as "red" and "green" than when they are presented with "poor" examples such as "pink" or "light green." The result of this experiment was interpreted as supporting the _____ approach to categorization.
prototype
Relationships Between Categories: Semantic Networks
1. Hierarchical Model (Collins and Quillian) -Nodes (concepts) are connected through links (relations) -Concepts organized hierarchically, show property inheritance -Cognitive Economy: Stored shared properties just once at a higher-level node
Input Units Hidden Units Output Units
1. Units in a connectionist network that are activated by stimulation from the enviornment 2. Units in a connectionist network that are located between input units and output units. 3. Units in a connectionist network that contain the final output of the network. *A stimulus presented to the input units is represented by the pattern of activity that is distributed across other units.
How are objects placed into categories?
1.Definitonal Approach: Does an object have the defining features of the category -This approach has been proven to be wrong 2. Prototype Approach: Does an object resemble a "typical" memory of the category? - Evidence: Effects of Protypicality 1. Fruit example 2. Sentence verification technique (RT) shows typicality effect -higher reaction time for apple than a pomegranate 3. Priming - Color Rosch 3. Exemplar Approach: Does an object resemble one or more examples of the category
Which of the following reaction time data sets illustrates the typicality effect for the bird category, given the following three trials?
583: 653: 518 msec
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 store at a higher-level node in the network. For example, the property "can fly" would be stored at the node for "bird" rather than at the node for "canary"
In evaluating retrieval rates for category information for a concept, Collins and Quillian's semantic network approach would predict the slowest reaction times for which of the following statements using a sentence verification technique?
A field sparrow is an animal.
Concepts
A mental representation of a class or individual. Also, the meaning ob objects, events, and abstract ideas. An example of a concept would be the way a person mentally represents "cat" or "house"
The Hub and Spoke Model
A model of semantic knowledge that proposes that areas of the brain that are associated with different functions are connected to the anterior temporal lobe, which integrates information from these areas.
Connectionism
A network model of mental operation that proposes that concepts are represented in networks that are modeled after neural networks. This approach to describing the mental representation of concepts is also called the parallel distributed processing approach (PDP)
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 non word.
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.
________ is a "typical" or "average" member of a category.
A prototype
Category-Specific Memory Impairment
A result of brain damage in which the patient has trouble recognizing objects in a specific category.
Prototype
A standard used in categorization that is formed by averaging that category members a person has encountered in the past.
Sentence Verification Technique
A technique in which the participant is asked to indicated whether a particular sentence is true or false. For example, sentences like "An apple is a fruit" have been used in studies on categorization.
Spreading Activation
Activity that spreads out along any link in a semantic network that is connected to an activated node.
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.
Semantic Network Approach
An approach to understanding how concepts are organized in the mind that proposes that concepts are arranged in networks.
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.
Hierarchical Model
As applied to knowledge representation, a model that consists of levels arranged so that more specific concepts, such as a canary or salmon, are at the bottom and more general concepts, such as bird, fish, or animal, are at higher levels
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.
Which approach to categorization can more easily take into account atypical cases such as flightless birds?
Exemplar
Sensory-functional (S-F) hypothesis
Explanation oh how semantic information is represented in the brain that stated that the ability to differentiate living things are artifacts depends on one system that distinguishes sensory attributes and another system that distinguishes function.
Category
Groups of objects that belong together because they belong to the same class of objects, such as "houses," "furniture," or "schools"
Basic Level
In Rosch's categorization scheme, the level below the global level (e.g. "table" or "chair") for the global category above which much information is lost and below which little is chained
Exemplars
In categorization, members of a category that a person has experienced in the past
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.
Exemplar Approach in Categorization
The approach to categorization in which members of a category are judged against exemplars - examples of members of the category that the person has encountered in the past
Units
The circles in the connectionist Approach
Definitional Approach to Categorization
The idea that we can decide whether something is a member of a category by determining whether the objet meets the definition of the category.
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.
Superordinate Level or Global Level
The most general category level distinguished by Rosch - for example, "furniture"
Subordinate Level or Specific Level
The most specific category level distinguished by Rosch- for example, "kitchen table"
Categorization
The process by which objects are placed in categories.
Connectionist Network
The type of network proposed by the connectionist approach to the representation 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 with semantic networks, in which specific categories are represented at individual nodes. -Input units send signals to hidden units, which send signals to output units
Family Resemblance
Things in a category resemble each other in a number of ways. -Experimental Result: -Higher ratings for high-prototypical items when people rate how "good" a member of the category it is (Rosch)
If we were conducting an experiment on the effect knowledge has on categorization, we might compare the results of expert and non-expert groups. Suppose we compare horticulturalists to people with little knowledge about plants. If we asked the groups to name, as specifically as possible, five different plants seen around campus, we would predict that the expert group would primarily label plants on the ______ level, while the non-expert group would primarily label plants on the ______ level.
specific (subordinate); basic
Collins and Quillian explained the results of priming experiments by introducing the concept of _____ into their network model.
spreading activation
Items high on prototypicality have ______ family resemblances.
strong
The connectionist network has learned the correct pattern for a concept when
the error signals are reduced to nearly none and the correct properties are assigned.
Rosch and coworkers conducted an experiment in which participants were shown a category label, like car or vehicle, and then, after a brief delay, saw a picture. The participants' task was to indicate as rapidly as possible whether the picture was a member of the category. Their results showed
the priming effect was most robust for basic level categories.
One reason why basic level categories may be "psychologically privileged" is that
you lose a lot of details when jumping to a global category, but gain only a few details by jumping to a specific category.
