Chapter 8 General Knowledge How do we know what properties something has, and which of its properties should be generalized to other objects? How is the.

Chapter 8 General Knowledge How do we know what properties something has, and which of its properties should be generalized to other objects? How is the knowledge underlying these abilities acquired, and how is it affected by brain disorders?

Introduction semantic memory schemas
We have an enormous amount of information at our disposal, and we use this information efficiently and accurately. Cognition 7e, Margaret Matlin Chapter 8

The Structure of Semantic Memory
Background on Semantic Memory semantic memory - encyclopedic knowledge, lexical or language knowledge, conceptual knowledge category concept semantic memory allows us to: code objects make inferences decide which objects are similar Cognition 7e, Margaret Matlin Chapter 8

Cognition 7e, Margaret Matlin Chapter 8

The Feature Comparison Model Concepts are stored in memory according to a list of necessary features or characteristics. Description of the Feature Comparison Model defining features - necessary characteristics features Cognition 7e, Margaret Matlin Chapter 8

The Feature Comparison Model Cognition 7e, Margaret Matlin Chapter 8

Research on the Feature Comparison Model sentence verification technique reaction times to answer true/false typicality effect—people reach decisions faster when an item is a typical member of a category, rather than an unusual member problem—very few of the concepts we use in everyday life can be captured by a specific list of necessary, defining features Cognition 7e, Margaret Matlin Chapter 8

The Feature Comparison Model Conclusions about the Feature Comparison Model can account for typicality effect, but research does not support the idea that category membership is based on a list of necessary features feature comparison model assumes that individual features are independent of one another, however many features are correlated feature comparison model does not explain how the members of categories are related to one another Cognition 7e, Margaret Matlin Chapter 8

The Prototype Approach Eleanor Rosch—we organize each category on the basis of a prototype, which is the item that is most typical and representative of the category prototype approach—you decide whether an item belongs to a category by comparing that item with a prototype – personal experience a prototype is an abstract, idealized example; may not exist members of a category differ in prototypicality graded structure—all members of categories are not created equal Cognition 7e, Margaret Matlin Chapter 8

Characteristics of Prototypes 1. Prototypes are supplied as examples of a category Mervis and colleagues (1976) prototype ratings for examples of categories items rated most prototypical were the same items that other people had supplied most often in the category norms accounts for typicality effect—when judging whether an item belongs to a particular category, typical items judged faster than atypical items Cognition 7e, Margaret Matlin Chapter 8

Characteristics of Prototypes 2. Prototypes are judged more quickly after semantic priming semantic priming effect—people respond faster to an item if it was preceded by an item with similar meaning priming facilitates the responses to prototypes more than it facilitates the responses to nonprototypes priming inhibits judgments for nonprototypes (Rosch color studies) Cognition 7e, Margaret Matlin Chapter 8

Priming examples Orthographic Morphological Semantic Prime Target corner CORN friendly FRIEND idea NOTION turnip TURN punishment PUNISH crazy INSANE tinsel TIN wonderful WONDER admire LIKE bulletin BULLET active ACT pick CHOOSE topple TOP greatness GREAT touch FEEL Cognition 7e, Margaret Matlin Chapter 8

Characteristics of Prototypes 3. Prototypes share attributes in a family resemblance category family resemblance no single attribute shared by all examples of a concept each example has at least one attribute in common with some other example of the concept no single attribute serves as the necessary and sufficient criterion for membership in the category Cognition 7e, Margaret Matlin Chapter 8

3. Prototypes share attributes in a family resemblance category (continued) Rosch and Mervis (1975) prototypicality judgments about members of several categories list attributes possessed by each item the most prototypical item also had the largest number of attributes in common with the other items in the category Cognition 7e, Margaret Matlin Chapter 8

The Prototype Approach Levels of Categorization super-ordinate-level categories basic-level categories subordinate-level categories Cognition 7e, Margaret Matlin Chapter 8

The Prototype Approach Levels of Categorization 1. Basic-level names are used to identify objects Rosch and colleagues (1976) ask people to look at pictures and identify objects people prefer to use basic-level names produce basic-level names faster than superordinate or subordinate names when presented with superordinate or subordinate names, frequently remember the basic-level version when later tested for recall Cognition 7e, Margaret Matlin Chapter 8

The Prototype Approach Levels of Categorization 2. Basic-level names are more likely to produce the semantic priming effect priming with basic-level names is helpful priming with superordinate names is not helpful Cognition 7e, Margaret Matlin Chapter 8

The Prototype Approach Levels of Categorization 3. Different levels of categorization activate different regions of the brain. superordinate terms are more likely than basic-level terms to activate part of the prefrontal cortex subordinate terms are more likely than basic-level terms to activate part of the parietal region Example: Animal Horse Race Horse Cognition 7e, Margaret Matlin Chapter 8

Conclusions About the Prototype Approach can account for our ability to form concepts for groups that are loosely structured can be applied to social relationships, inanimate objects, nonsocial categories Problems concepts can be unstable and variable (e.g., prototype ratings can shift based on experience) we often do store specific information about individual examples of a category better for general population than for experts Cognition 7e, Margaret Matlin Chapter 8

Individual Differences: Expertise and Prototypes expertise practice experts construct prototypes in a different fashion Cognition 7e, Margaret Matlin Chapter 8

Individual Differences: Expertise and Prototypes Lynch, Coley, and Medin (2000) tree experts experts' best examples were very tall, well-behaved trees rather than typical, average trees for novices the ratings were based on familiarity rather than typicality Cognition 7e, Margaret Matlin Chapter 8

Individual Differences: Expertise and Prototypes Johnson and Mervis (1997) experts and novices prefer different levels of categorization bird-watching experts provide very specific names for birds, rather than basic-level term Cognition 7e, Margaret Matlin Chapter 8

Individual Differences: Expertise and Prototypes
Example of Expert Prototypes Cognition 7e, Margaret Matlin Chapter 8

The Exemplar Approach first learn some specific examples of a concept (exemplars) then classify each new stimulus by deciding how closely it resembles those specific examples Cognition 7e, Margaret Matlin Chapter 8

A Representative Study on the Exemplar Approach Heit and Barsalou (1996) provide first example that comes to mind of seven basic-level categories different group rates the typicality of each category and of each example with respect to "animal" researchers try to create equation to predict typicality of the categories based on the exemplars in terms of frequency and typicality ratings Cognition 7e, Margaret Matlin Chapter 8

Heit and Barsalou (1996) (continued) exemplar frequency and exemplar typicality did accurately predict which of the seven categories were most typical for the superordinate category "animal" less typical exemplars increase the correlation when asked a question about a category, people don't just consider prototypes, they also include information about less typical examples of the category Cognition 7e, Margaret Matlin Chapter 8

Comparing the Exemplar Approach with Other Approaches exemplar approach proposes that we do not need any list of features (as in feature comparison approach), because all the necessary information is stored in the specific exemplars make decisions about category membership by comparing to a stored representation (like prototype approach), but the stored representation is a collection of numerous specific members of the category, not a typical member Cognition 7e, Margaret Matlin Chapter 8

Comparing the Exemplar Approach with Other Approaches (continued) do not need to perform any kind of abstraction process (don't need to devise list of features or a prototype) which would force you to discard useful, specific data about individual cases Cognition 7e, Margaret Matlin Chapter 8

Problems with the Exemplar Approach exemplar approach may be more suitable for categories with relatively few members (so as not to overwhelm semantic memory) Requires too much memory prototype approach may be more suitable for categories with numerous members individual differences in representations may be substantial Cognition 7e, Margaret Matlin Chapter 8

Conclusions both approaches may coexist different hemispheres left—prototypes right—exemplars) different categories may require different strategies for category formation Cognition 7e, Margaret Matlin Chapter 8

Network Models network models of semantic memory propose a netlike organization of concepts in memory, with many interconnections; the meaning of a concept depends on the concepts to which it is connected Cognition 7e, Margaret Matlin Chapter 8

The Collins and Loftus Network Model semantic memory is organized in terms of netlike structures, with numerous interconnections when we retrieve information , activation spreads to related concepts Node = concept link spreading activation Cognition 7e, Margaret Matlin Chapter 8

Cognition 7e, Margaret Matlin Chapter 8
Cognitive Psychology and Cognitive Neuroscience/Knowledge Representation and Hemispheric Specialisation Cognition 7e, Margaret Matlin Chapter 8

The Collins and Loftus Network Model sentence verification tasks—activations spreads from the concept nodes until an intersection is located (or not) frequently used links have greater strengths; activation travels faster between those nodes explains typicality effect, but has been superceded by more complex theories Cognition 7e, Margaret Matlin Chapter 8

Network Models Anderson's ACT Theories ACT-R—Automatic Components of Thought-Rational; attempts to account for all of cognition propositional network proposition—smallest unit of knowledge that can be judged either true or false; abstract representation Cognition 7e, Margaret Matlin Chapter 8

ACT* distinguishes among three types of memory structures Declarative memory (LTM) takes the form of a semantic net linking propositions, images, and sequences by associations. Procedural memory (LTM) represents information in the form of productions Working memory is that part of long-term memory that is most highly activated. Cognition 7e, Margaret Matlin Chapter 8

A propositional network Cognition 7e, Margaret Matlin Chapter 8

Cognition 7e, Margaret Matlin Chapter 8

Productions in Procedural memory Productions represent knowledge about how we do things Example: knowledge about how to type the letter "Q" on a keyboard, about how to drive, or about how to perform addition. "IF” a sensory precondition "THEN” action Cognition 7e, Margaret Matlin Chapter 8

Anderson's ACT Theories (continued) activation can spread limited capacity of working memory can restrict the spreading if many links are activated simultaneously, then each link receives relatively little activation Cognition 7e, Margaret Matlin Chapter 8

Cognition 7e, Margaret Matlin Chapter 8

Network Models The Parallel Distributed Processing Approach McClelland and colleagues parallel distributed processing (PDP) approach— cognitive processes can be represented by a model in which activation flows through networks that link together a large number of simple, neuron-like units Artificial Neural Network (ANN) - an information processing paradigm that is inspired by the way biological nervous systems, such as the brain, process information Cognition 7e, Margaret Matlin Chapter 8

Compare PDP with Semantic
FIGURE 1 | The hierarchical propositional model of Quillian applied to the domain of living things, as adapted by Rumelhart Cognition 7e, Margaret Matlin Chapter 8

Compare PDP with Semantic
FIGURE 3 | Our depiction of the connectionist network used by Rumelhart Cognition 7e, Margaret Matlin Chapter 8

Why use neural networks? Neural networks is to learn to associate patterns in input data to an output on their own involves modifying the connection weights Gives them the ability to Derive meaning from complicated or imprecise data Recognize input that has not seen before Cognition 7e, Margaret Matlin Chapter 8

How Do Neural Networks Work? The output of a neuron is a function of the weighted sum of the inputs plus a bias Cognition 7e, Margaret Matlin Chapter 8

How Do Neural Networks Learn (to associate output with an input pattern)? If the output is not correct, the weights are adjusted according to a formula Uses the difference between input and output Goal - Minimizing the error in the network Most common measure of error is the mean square error: E = (target – output)2 Cognition 7e, Margaret Matlin Chapter 8

Neural Network Example
Handwriting Recognition Cognition 7e, Margaret Matlin Chapter 8

Neural Network Example Bank Loans
Imagine a highly experienced bank manager who must decide which customers will qualify for a loan. Her decision is based on a completed application form that contains ten questions. The bank manager's experience allows her to use "Intuition” that will enable her to recognize certain patterns that her brain has become attuned to. If we had a large number of loan applications as input, along with the manager's decisions as output, a neural network could be "trained" on these patterns. The inner workings of the neural network have enough mathematical sophistication to reasonably simulate the expert's intuition. Cognition 7e, Margaret Matlin Chapter 8

Parallel Distributed Processing Assumptions Cognitive processes arise from the interactions of neurons through synaptic connections. The knowledge in such interactive and distributed processing systems is stored in the strengths of the connections and is acquired gradually through experience Cognition 7e, Margaret Matlin Chapter 8

Three Central Characteristics of PDP 1. Cognitive processes are based on parallel operations, rather than serial operations. Therefore, many patterns of activation may be proceeding simultaneously. Cognition 7e, Margaret Matlin Chapter 8

Three Central Characteristics of PDP A network contains basic neuron-like units or nodes, which are connected together so that a specific node has many links to other nodes (hence the alternate name for the theory: connectionism). PDP theorists argue that most cognitive processes can be explained by the activation of these networks. Cognition 7e, Margaret Matlin Chapter 8

Three Central Characteristics of PDP A concept is represented by the pattern of activity distributed throughout a set of nodes. Notice that this view is very different from the commonsense idea that all the information you know about a particular person or object is stored in one specific location in the brain. Cognition 7e, Margaret Matlin Chapter 8

Features & Concepts of PDP serial search vs. parallel search memory can cope with partial and/or partly incorrect information characteristics connected in a mutually stimulating network spontaneous generalization—draw a conclusion about a general category default assignment—draw a conclusion about a specific member of a category Cognition 7e, Margaret Matlin Chapter 8

Other important characteristics of PDP 1. The connections between these neuron-like units are weighted, and the connection weights determine how much activation one unit can pass on to another unit. When a unit reaches a critical level of activation, it may affect another unit, either by exciting it (if the connection weight is positive) or by inhibiting it (if the connection weight is negative). Cognition 7e, Margaret Matlin Chapter 8

Other important characteristics of PDP Every new piece of information you learn will change the strength of connections among relevant units by adjusting the connection weights. 4. Sometimes we have only partial memory for some information, rather than complete, perfect memory. The brain’s ability to provide partial memory is called graceful degradation (e.g., tip-of-the-tongue phenomenon, brain function after accident or stroke) Cognition 7e, Margaret Matlin Chapter 8

Current Status of PDP Theory  generally consistent with the neurological design or neurons and the brain  works better for tasks in which several processes typically operate simultaneously; tasks requiring serial processing may be accounted for by other models  PDP explains: word superiority effect, retroactive interference, category formation, complex decision making Cognition 7e, Margaret Matlin Chapter 8

Current Status of Theory (continued)  used to study social psychology, developmental psychology, cognitive disorders can explain situations where learning accumulates gradually across trials The parallel distributed processing approach to semantic cognition James L. McClelland & Timothy T. Rogers Nature Reviews Neuroscience 4, (April 2003) Cognition 7e, Margaret Matlin Chapter 8

Parallel Distributed Processing Approach Problems not currently structured enough to handle the subtleties and complexities of semantic memory has trouble explaining why we sometimes forget extremely well-learned information when we learn additional information cannot explain why we sometimes can recall earlier material when it has been replaced by more current material Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts schema—generalized knowledge about a situation, an event, or a person schema theories especially helpful when psychologists try to explain how people process complex situations and events Scripts What Your Favorite Porn Says About Who You Are lust/201201/what-your-favorite-porn-says-about-who- you-are Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Background on Schemas and Scripts
People encode "generic" information about a situation or event, then use this information when in that situation or a similar situation This “package” of information is called a schema heuristics—general rules that are typically accurate schemas can lead to errors Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Background on Schemas and Scripts Piaget Bartlett
social psychology schema therapy script—simple, well-structured sequence of events scripts recalled more accurately if identified in advance Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Enhanced Memory for Schema-Consistent Material
Brewer and Treyens (1981) recall objects from waiting room; highly likely to recall objects consistent with "office schema" "remembered" items that were not in the room, but were consistent with "office schema" Neuschatz and coauthors (2002) "lecture schema" Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Enhanced Memory for Schema-Inconsistent Material
people are more likely to recall schema-inconsistent material when that material is vivid or surprising Davidson (1994)—read stories describing well-known schemas; people especially likely to recall schema- inconsistent events that interrupted the normal, expected story Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts The Status of Schemas and Memory Selection
Rojahn and Pettigrew (1992)—meta-analysis; schema- inconsistent material was somewhat more memorable However, when people "remember" events that never actually happened, they are likely to construct a schema-consistent event Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Schemas and Boundary Extension
Boundary extension—our tendency to remember having viewed a greater portion of a scene than was actually shown Intraub and colleagues—see photo then draw replica of photo; participants consistently produced a sketch that extended the boundaries beyond the view presented in the original photo – p. 270 relevance in eyewitness testimony situations Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Schemas and Memory Abstraction
abstraction—a memory process that stores the meaning of a message but not the exact words verbatim memory—word-for-word recall Cognition 7e, Margaret Matlin Chapter 8

The Constructive Approach Bransford and Franks (1971) listen to sentences from several different stories recognition test including new items people convinced that they had seen these new items before (false alarm) false alarms particularly likely for complex sentences consistent with the original schema false alarms unlikely for sentences violating the meaning of the earlier sentences Cognition 7e, Margaret Matlin Chapter 8

The Constructive Approach constructive model of memory—people integrate information from individual sentences in order to construct larger ideas; later cannot untangle the constructed information from the verbatim sentences Cognition 7e, Margaret Matlin Chapter 8

The Pragmatic Approach pragmatic view of memory—people pay attention to the aspect of a message that is most relevant to their current goals Cognition 7e, Margaret Matlin Chapter 8

The Pragmatic Approach Murphy and Shapiro (1994) read letters from "Samantha" to cousin or boyfriend bland vs. sarcastic comments recognition test on original, paraphrased, or irrelevant sentences Cognition 7e, Margaret Matlin Chapter 8

Pragmatic Approach Cognition 7e, Margaret Matlin Chapter 8

The Pragmatic Approach Murphy and Shapiro (1994) (continued) correct recognition was higher for sentences from the sarcastic condition than for sentences in the bland condition more false alarms for paraphrases of bland sentences than sarcastic sentences more accurate in their verbatim memory for the sarcastic version than for the bland version Cognition 7e, Margaret Matlin Chapter 8

The Current Status of Schemas and Memory Abstraction two approaches (Constructive and Pragmatic) quite compatible in many cases we integrate information into large schemas in some cases we know that specific words matter and pay close attention to precise wording Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts In Depth: Schemas and Inferences in Memory
inferences—logical interpretations and conclusions that were not part of the original stimulus material Cognition 7e, Margaret Matlin Chapter 8

The Classic Research on Inferences Bartlett (1932)—memory as the complex interaction between the participants' prior knowledge and the material presented; individual's unique interests and personal background often shape the contents of memory "The War of the Ghosts" study—Native American story read and recalled by British students Cognition 7e, Margaret Matlin Chapter 8

The Classic Research on Inferences "The War of the Ghosts" study (continued) Participants tended: to omit material that didn't make sense from their own viewpoint to shape the story into a more familiar framework to add extra material to the story, making inferences so that the story made more sense from their perspective to borrow more heavily from their previous knowledge as time passed before additional recall Cognition 7e, Margaret Matlin Chapter 8

Research on Inferences Based on Gender Stereotypes gender stereotypes—widely shared sets of beliefs about the characteristics of females and males Cognition 7e, Margaret Matlin Chapter 8

Research on Inferences Based on Gender Stereotypes Explicit Memory Task Dunning and Sherman (1997) read sentences followed by recognition-memory test "new" sentences consistent or inconsistent with gender stereotypes more likely to mistakenly "remember" a new sentence as "old" when it was consistent with a gender stereotype Cognition 7e, Margaret Matlin Chapter 8

Research on Inferences Based on Gender Stereotypes Implicit Memory Tasks 1. Using neuroscience techniques to assess gender stereotypes Osterhout, Bersick and McLaughlin (1997)—ERP technique stereotype-consistent sentences vs. stereotype- inconsistent sentences change in ERPs for stereotype-inconsistent words but not for stereotype-consistent words Cognition 7e, Margaret Matlin Chapter 8

Research on Inferences Based on Gender Stereotypes Implicit Memory Tasks 2. Using the Implicit Association Test to assess gender stereotypes Nosek, Banaji, and Greenwald (2002) Implicit Association Test (IAT)—based on the principle that people can mentally pair related words together much more easily than they can pair unrelated words Cognition 7e, Margaret Matlin Chapter 8

Research on Inferences Based on Gender Stereotypes Implicit Memory Tasks 2. Using the Implicit Association Test to assess gender stereotypes (continued) Stereotype-Consistent pairings (male/math vs. female/arts) Stereotype-Inconsistent pairings (female/math vs. male/arts) Cognition 7e, Margaret Matlin Chapter 8

Research on Inferences Based on Gender Stereotypes Implicit Memory Tasks 2. Using the Implicit Association Test to assess gender stereotypes (continued) participants responded significantly faster to the stereotype-consistent parings than to the stereotype-inconsistent pairings technique can be used to examine attitudes, as well as stereotypes Cognition 7e, Margaret Matlin Chapter 8

Implications of Inferences for Persuasion Advertising Harris and colleagues (1989) read stories containing advertising slogans direct claim vs. implied claim people who had seen the implied-claim version often believed they had seen the direct-claim version Consumers be careful Cognition 7e, Margaret Matlin Chapter 8

Implications of Inferences for Persuasion Politics statements can be technically accurate but still misleading listeners make incorrect inference people make inferences only in certain situations; often recall material in its original form Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Schemas and Integration in Memory
Integration and Delayed Recall background knowledge may not encourage schema- consistent integration if people are tested immediately after the material is learned Harris and colleagues (1989) story consistent with U.S. or traditional Mexican culture no chaperone/chaperone recall after 30 minutes—no tendency for the Mexican- schema stores to shift in the direction consistent with U.S. schemas after two days—the students had shifted a significant number of story details Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Schemas and Integration in Memory
Integration and Limited Memory Capacity schemas are more likely to influence memory integration when memory capacity is strained during recall, but not on a relatively simple task Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Conclusions About Schemas
1. We often select material for memory that is inconsistent with our schemas. 2. We may indeed remember that we saw only a portion of an object, rather than the complete object. 3. We frequently recall the exact words of a passage as it was originally presented. Cognition 7e, Margaret Matlin Chapter 8

Schemas and Scripts Conclusions About Schemas
4. We often avoid making inappropriate inferences. 5. We may keep the elements in memory isolated from each other, rather than integrated together. 6. When we are recalling information from our real-life experiences—rather than information created by researchers—we may be more accurate. Cognition 7e, Margaret Matlin Chapter 8

Chapter 8 General Knowledge How do we know what properties something has, and which of its properties should be generalized to other objects? How is the.

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Chapter 8 General Knowledge How do we know what properties something has, and which of its properties should be generalized to other objects? How is the.

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Presentation on theme: "Chapter 8 General Knowledge How do we know what properties something has, and which of its properties should be generalized to other objects? How is the."— Presentation transcript:

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