Psych 256- Exam 3 I. Knowledge and Categorization: 1.Categories and Concepts:-concept: mental representation that is used for a variety of cognitive functions, including memory, reasoning, and using and understanding language. Ex: when you think about your cats you are drawing on info (concept or mental representation of cats) which helps you know how they behave, what they look like, etc.-categories: placing things into groups (like seeing Vehicles and splitting them into groups like SUVs, cars, trucks, etc.) -The most important function of categories is to help us understand individual cases we have never seen before. Ex: being able to say that the furry creature across the street is a cat provides more info about it- therefore categories have been called “pointers to knowledge” because once you know general info about an object ina category, you can begin to focus on specific aspects. 2.How are objects placed into Categories:- definitional approach: using this, we can decide weather something is a member of a category by determining whether a particular object meets the definition of the category. The problem with this is that not all of the members of everyday categories have the same features. - sentence verification task: given sentences and you have to answer yes if you believe it is correct and no if you believe it is false. Tests to see how rapidly people can answer questions about an object’s category.3.Prototype Approach:-according to the prototype approach, membership in a category is determined by comparing the object to a prototype that represents the category. A prototype is a typical member of that category.-High prototypicality means that a category member closely resembles the category prototype. Low prototypicality means that the category member does not closely resemble a typical member of the category. -Family Resemblance: the idea that things in a particular category resemble one another in a number of ways, so instead of setting a criteria that every member of the category must meet, this approach allows for some variation within a category. -Rosh and Mervis: Gave a list of common objects and told participants tolabel and list as many characteristics that they felt were common to these objects. If two objects (like chair and sofa) have a lot of overlap with characteristics, then their family resemblance is high, and little overlap means family resemblance is low.-Typicality Effect: people react rapidly to members of a category that are “typical” of the category. It takes less time to say “a robin is a bird” because it is more common, it would take more time to say something less common like ostrich.-Naming Effect: people are more likely to list some objects than others when asked to name objects in a category (high-prototypical items named first)-Priming Effect: presentation of one stimulus affects responses to a stimulus that follows. (faster same-different color judgments for high-prototypical items)4.Exemplar Approach:-the exemplar approach involves determining whether an object is similar to a standard object. In this case, the standard object is not a single “average” member of the category, now it is in the form of an exemplar, which are members of the category that people have encountered in the past.-Advantages: one advantage is that by using real examples, it can more easily take into account atypical cases such as flightless birds. This abilityto take into account individual cases means that the exemplar approach doesn’t discard information that might be useful later. 5.Hierarchical Organization of Categories:-this is the type of organization where larger, more general categories are divided into smaller more specific categories.-Global Level: very general, an example would be furniture-Basic Level: less general, but still not specific, an example would be saying chair, or table under the global category of furniture.-Specific Level: very specific, an example would be saying kitchen table or dining room chair.-the basic level is special because going above it to the global level results in a large loss of information, and going below it to specific results in little gain of information. -Expertise influences Categorization: people who have more expertise in a field, or are a professional in what they do are more able to specificly label objects (such as birds or plants) than others who have less expertise.II. Semantic Networks and Connectionism: 1.Semantic Network Approach:-Collins and Quillian- goal was to develop a computer model of human memory-created a network consisting of nodes that are connected by links. Each node represents acategory or concept and concepts are placed in the network so that related concepts are connected by the links.-Spreading Activation: activity that spreads out along any link that is connected to an activated node. Ex: moving through the network from robin to bird activates the node at bird and the link we use to get from robin to bird. -Meyer and Schvaneveldt: the idea that spreading activation can influence priming- used a method called the lexical decision task where participants read stimuli, some of which are words and some are not wordsand the task is to indicate as quickly as possible whether each entry is a word or a non word. The idea proposed was that retrieving one word frommemory triggered a spread of activation to other nearby locations in a network- this is why the response to related words is faster than the response to unrelated words.-Problems with the model: the model could not explain the typicality effect, in which reaction times for statements about an object are faster for more typical members of a category than for less typical members. They say canary and ostritch are equally as fast and typical because they are both one node away from bird, when really they are not.-Collins and Loftus: proposed a model similar to the nodes model above in which concepts that are more closely related are connected by shorter lines. The shorter links predict faster reaction times for the more typical things.-Assessment of Semantic Network Theories: 1. Explanatory power: the theory can explain why a particular result occurred by making a statement like “behavior A occurred because…” 2. Predictive power: the theory can predict the results of a particularexperiment by making a statement like “under these circumstances, behavior B will occur…” 3.