PSYC 310 3rd Edition Text Lecture 14Outline of Last Lecture I. Schemas & ScriptsII. Construction of MemoriesIII. Power of SuggestionIV. False MemoriesV. Errors in Eyewitness TestimoniesVI. What is Being Done?Outline of Current Lecture I. KnowledgeII. CategorizationIII. Prototype ApproachIV. Exemplar ApproachV. Hierarchical OrganizationVI. Semantic NetworksCurrent LectureI. Knowledgea. Concept: mental representation used for a variety of cognitive functionsi. Difficult to define because its features are not all present in every instanceb. Categorization is the process by which things are placed into groups called categoriesi. A concept can be a category and can also be a member of other categoriesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.ii. Can other animals form concepts?II. Categorizationa. Helps to understand individual cases not previously encounteredb. “Pointers to knowledge”i. Categories provide a wealth of general information about an itemii. Allow us to identify the special characteristics of a particular itemiii. Ex: Capybara1. Rodenta. Mammali. Produces milkii. Covered in furiii. Reproduces sexuallyiv. Mammal skeleton and organs1. Big incisors that keep growing2. Related to rats and rabbitsc. Determine category membership based on whether the object meets the definition of the categoryi. Does not work wellii. Not all members of everyday categories have the same defining featuresd. Family resemblancei. Things in a category resemble one another in a number of waysIII. Prototype Approacha. Prototype: an abstract representation of the “typical” member of a categoryi. Characteristic features that describe what members of that concept are likeii. An average of category members encountered in the pastiii. Contains the most salient featuresb. High-prototypicality:i. Category member closely resembles category prototype1. “Typical” member2. For category “bird” = robinc. Low-prototypicality:i. Category member does not closely resemble category prototype1. For category “bird” = penguind. Strong positive relationship between prototypicality and family resemblancee. When items have a large amount of overlap with characteristics of other items in the category, the family resemblance of these items is highf. Low overlap = low family resemblanceg. Typicality Effect: prototypical objects are processed preferentiallyi. Highly prototypical objects judged more rapidly1. Sentence verification techniqueii. Prototypical objects are named more rapidly (when listing objects)iii. Prototypical category members are more affected by a priming stimulus1. Hearing “green” primes a highly prototypical “green”IV. Exemplar Approacha. Concept is represented by multiple examples (rather than a single prototype)b. Examples are actual category members (not abstract averages)c. To categorize, compare the new item to stored examplesd. Similar to prototype view in that a category’s representation is not a hard andfast definitione. Different from prototype because representation is not abstracti. Descriptions of specific examplesf. The more similar a specific exemplar is to a known category member, the faster it will be categorizedg. Explains typicality effecth. Easily takes into account atypical casesi. Easily deals with variable categoriesj. Prototypes or Exemplars?i. May use bothii. Exemplars may work best for small categoriesiii. Prototypes may work best for larger categoriesiv. Some evidence that people use prototypes for new categories1. Gradually start to use exemplars as knowledge is gainedV. Hierarchical Organizationa. Any category may be a part of a larger category and can also have sub-categoriesi. Categories at a “lower” level have all the characteristics of their parent categoriesb. Basic level: categorization that adequately discriminates between common stimulic. Subordinate level: more specific than basicd. Superordinate level: more general than basice. As we travel down the hierarchy, within category similarity increases, and between category similarity decreasesf. Evidence that basic level is special:i. People almost exclusively use basic level names in free-naming tasksii. Quicker to identify basic-level category member as a member of a categoryiii. Children learn basic-level concepts sooner than other levelsiv. Basic-level is much more common in adult discourse than names for superordinate categoriesv. Different cultures tend to use the same basic-level categories, at least for living thingsg. To fully understand how people categorize objects, one must consider properties of objects, learning and experience of perceiversh. What is “basic” depends on one’s knowledge and experiencei. Experts tend to categorize at a more subordinate level than novices doVI. Semantic Networksa. Concepts are arranged in networks that represent the way concepts are organized in the mindb. Collins and Quillian (1969)i. Node = category/conceptii. Concepts are linkediii. Model for how concepts and properties are associated in the mindc. Cognitive Economy: shared properties are only stored at higher level nodesd. Exceptions are stored at lower level nodese. Inheritancei. Lower-level items share properties of higher level itemsii. Cognition must travel up the hierarchy to retrieve info from stored at higher