Chapter 9 Flashcards
(46 cards)
anterior temporal lobe
(ATL) area in the temporal love. Damage to the ATL has been connected with semantic deficits in dementia patients and with the savant syndrome
back propagation
process by which learning can occur in a connectionist network, in which an error signal is transmitted backwards 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
basic level
in Rosch’s categorization scheme, the level below the global (superordinate) level (e.g., “table” or “chair” for the superordinate category “furniture”). 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
categorization
process by which objects are placed in categories
category
groups of objects that belong together because they belong to the same class of objects, such as “houses”, “furniture”, or “schools”
category-specific memory impairment
result of brain damage in which the patient has trouble recognizing objects in a specific category
cognitive economy
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 at the node for “canary”
concept
mental representation of a class of 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”.
conceptual knowledge
knowledge that enables people to recognize objects and events and to make inferences about their properties
connection weight
in connectionist models, a connection weight determines the degree to which signals sent from one unit either indrease or decrease the activity of the next unit
connectionism
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 (PDP) approach
connectionist network
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 ar individual nodes.
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.
definitional 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
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
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
exemplar
in categorization, members of a category that a person has experienced in the past
exemplar approach to 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
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 the definitional approach, which states that an object belongs to a category only when it meets a definite set of criteria
global level
the highest level in Rosch’s categorization scheme (e.g. “furniture” or “vehicles”
graceful degradation
disruption of performance due to damage to a system that occurs only gradually as parts of the system re damaged. This occurs in some cases of brain damage and also when parts of a connectionist network are damaged
hidden units
units in a connectionist network that are located between input units are output units
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
hierarchical organization
organization of categories in which larger, 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
