Chapter 9: Conceptual Knowledge Flashcards
conceptual knowledge
enables us to recognize objects and events and to make inferences about their properties
concept
mental representation used for a variety of cognitive functions
categorization
the process by which things are placed into groups called categories. Categories are all possible examples of a particular concept.
why categories are useful
help to understand individual cases not previously encountered, “pointers to knowledge”, categories provide a wealth of general info about an item, allows us to identify the special characteristics of a particular item.
definitional approach to categorization
determine category membership based on whether the object meets the definition of the category, doesn’t work well, not all members of everyday categories have the same defining features.
family resemblance
things in a category resemble one another in a number of ways, but do not have to share every feature
the prototype approach
an abstract representation of the “typical” member of a category, characteristic features that describe what members of that concept are like, an average category members encountered in the past, contains most salient features, true of most instances of that category.
low prototypicality
a category member does not closely resemble the category prototype
high prototypicality
a category member closely resembles the category prototype
typicality effect
prototypical objects are processed preferentially. Prototypical objects are judged more rapidly.
Rosch experiment
hearing “green” primes a highly prototypical “green”, showed that priming resulted in faster “same” judgements for prototypical colors than for non-prototypical colors.
the exemplar approach
concept is represented by multiple examples rather than one single prototype, examples are actual category members, to categorize you compare the new item to stored examples. Explains typicality effect, easily takes into account atypical cases, deals with variable categories.
exemplar vs. prototype approach
exemplar is similar to prototype view because representing a category is not defining it. different because representation is not abstract, descriptions of specific examples. The more similar a specific exemplar is to a known category member, the faster it will be categorized. Exemplar works best for small categories, prototypes works best for larger categories.
Hierarchical organization
to fully understand how people categorize objects, one must consider properties of objects, and learning and experience of perceivers.
Semantic networks
concepts are arranged in networks that represent the way concepts are organized in the mind
Collins and Quillian experiment
found concepts are linked, model for how concepts and properties are associated in the mind. Node = category/concept. Results show greater distances are associated with longer reaction times, when verifying statements both about properties of canaries and about categories of which the canary is a member.
cognitive economy
shared properties are only stored at higher-level nodes, exceptions are stored at lower nodes.
spreading activation
activation is the arousal level of a nose. When a node is activated, activity spreads out along all connected links. Concepts that receive activation are primed and more easily accessed from memory.
Lexical decision task
participants read stimuli and are asked to say as quickly as possible whether the item is a word or not.
Meyer and Schvanveldt experiment
“yes” if both strings are words, “no” if not. Some pairs were closely associated, reaction time was faster for those pairs. Used spreading activation.
Criticism of Collins and Quillian
cannot explain typicality effect, cognitive economy, some sentence-verification results are problematic for the model.
Collins and Loftus modifications experiment
shorter links to connect closely related concepts, longer links for less closely related concepts, no hierarchical structure; based on person’s experience.
Assessment of semantic networks
it’s predictive and explanatory of some results, but not all. Generated multiple experiments, and lacks falsifiability - no rules for determining link length or how long activation will spread.
Sensory-functional hypothesis
different brain areas may be specialized to process information about different categories. Double dissociation for categories “living things” and “nonliving things”, category specific memory impairment.
Semantic category approach
specific neural circuits for specific categories
multiple factor approach
use distributed representation and crowding.
distributed representation
how concepts are divided within a category
crowding
when different concepts within a category share many properties. Example - animals all have eyes, legs, ability to move.
The embodied approach
knowledge of concepts is based on reactivation of sensory and motor processes that occur when we interact with the objects
mirror neurons
fire when we do a task or we observe another doing that same task
semantic somatotopy
correspondence between words related to specific body parts and the location of brain activation.
Levels of categories
Global - furniture, lose a lot of information, superordinate, umbrella term.
Basic - table, in the middle, some common features between global and specific.
Specific - kitchen table, gain just a little information, subordinate.
Why is the basic-level special?
people almost exclusively use basic-level names in free naming tasks. Quicker to identify basic-level category member as a member of a category. Children learn basic-level concepts sooner than other levels. Basic-level is much more common in adult discourse than names for superordinate categories. Different cultures tend to use the same basic-level categories, at least for living things.
