79 terms

Cognitive Psychology Chapter 8 General Knowledge

semantic memory
refers to our organized knowledge about the world

allows us to:
• organize objects according to concepts
• make inferences going beyond the information given
• decide which objects are similar
- static representation and interrelationships
- reaction time experiments (retrieval)
• sentence verification
• lexical decision (priming)
is a set of objects that belong together and are considered by the cognitive system to be at least partly equivalent
- Learning and category boundaries
- accuracy experiments (classification)
The Classical View (Aristotle)-nominal
categories - rule-based
- list of necessary and sufficient features
- examples
• Prime number: integer, only divisible by 1 and itself • Triangle: closed, 3-sided figure
• Bachelor: male, adult, unmarried, human
- assumes
• representation through feature lists
• membership is clear-cut
- are bookends furniture?
• no such thing as "better" and "worse" examples
- Rosch (1973, 1975)
» Typicality effect: Robins and Sparrows versus chickens,
penguins, and ostriches
» faster verification and stronger priming for typical
The Prototype View
B:in semantic memory, the proposal that ppl decide whether a particular item belongs to a category, based on a comparison btwn this item and a prototype, then it will be included within this category
- idealized best instance
• doesn't have to exist
• includes characteristic features
- resemblance to prototype
• Typical: many characteristic features
- Robin
-» small, flies, eats worms, lives in tree
• Atypical: few characteristic features
- the Pope
-» not young, doesn't live in an apartment

explains typicality
- even for well-defined categories (3 versus 57)
• explains hard to define concepts
• handles irregular items such as tomatoes
- problems w/ prototypes
• How to define boundaries?
• Resemblance depends on context
- Birds in the open plains versus backyard
• Sensitivity to particular exemplars
B: the mental representation of a category
o e.g. you have the concept of "fruit," which refers to your mental representation of the objects in that category
o academics and concepts: art history course, you may need to create a concept called "15th-century Felmish painting," and in a Spanish course, you learn a concept called "ppl whom you greet w/ the 'usted' form of a verb"
o allows you to make numerous inferences when you encounter new examples from category
situated cognition approach
B:we make use of information in the immediate environment or situation. Our knowledge often depends on the context that surrounds us
o w/ respects to "general knowledge" we tend to code a concept in terms of "context" in which we learned this information
Characteristic of PDP (4/4):
->>Consistent with the concept of "situated cognition," the current context often activates only certain components of a concept's meaning.
cognitive economy
A 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.
B: the item that is the best, most typical example of a category; the ideal representative of a category
o e.g. particular group of students on campus or academic major, nonprototype (you mean he's and art major, sure doesn't act like one); prototype: robin category: bird
-left hemi
Rosch: according to the prototype theory of semantic memory, the degree to which a member of a category is representative of its category
o E.g. robin and sparrow are prototypical birds, whereas ostrich and penguin are not
o However this depends on cogn approach due to context. If a zoo was mentioned then they would be considered
Hierarchical Semantic Network Model
-subordinate and superordinate nodes
-cogn economy
- prediction: semantic distance takes time
• Collins and Quinlan (1969) - number of links
» Level in hierarchy and property versus category - Conflicting results
• same action at different levels
- "a shark can move", "a fish can move", or "an animal can move"
» no difference
• the typicality effect (Rips et al.,1973)
- "a robin is a bird" versus "a turkey is a bird"
The Prototype Approach and Semantic Memory: Rosch
• organize each category on the basis of a prototype, the item that is most "typical" and representative of the category
• prototype approach—decide whether an item belongs to a category by comparing that item with a prototype
• members of a category differ in prototypicality
• graded structure—members of categories are not all created equal
graded structure
in the prototype approach to category representation, a description of the variation btwn the category's most representative or prototypical members, less prototypical members, and nonprototypical members
—members of categories are not all created equal
typicality effect
—when judging whether an item belongs to a particular category, typical items judged faster than atypical items

the observation that ppl judge typical items (prototypes) faster than items that are not typical (nonprototypes)
e.g.- "a robin(p) is a bird" versus "a turkey(np) is a bird"
Prototype & Categories: Mervis & colleagues
• 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
Characteristics of Prototypes (1/3):
1. Prototypes are supplied as examples of a category
Posner & Keele: Learning category names for random dot patterns
-unseen prototype
• people were trained with low or moderate distortions
- became sensitive to the unseen prototype in either case
- sense of variation with moderate-distortions
» Good at classifying new high distortions
• these results demonstrate
- people form unseen prototypes
- learning about variability is important
Characteristics of Prototypes
1. Prototypes are supplied as examples of a category
2. Prototypes are judged more quickly than nonprototypes, after semantic priming
3. Prototypes share attributes in a family resemblance category
Semantic priming effects
the observation that ppl respond faster to an item if it was preceded by an item w/ similar meaning
Family resemblance
the observation that -for some concepts - no single attribute is shared by all examples of the concept. However, each example has at least one attribute in common w/ some other example of the concept
Characteristic of Prototypes (3/3):
3. Prototypes share attributes in a family resemblance category
"Classic view:rule-based" vs. "prototype family resemblance" Kemler Nelson
People can learn rule (classical) or family resemblance (prototype)
- one defining feature (the nose)
- also family resemblance
- defining feature set in opposition to family resemblance
- if learned to recognize the faces • 60%resemblance
- if discriminated categories • 46%resemblance
Prototype view: Rosch & Mervis
• prototypicality judgments about members of several categories
• list the attributes possessed by each item
• The most prototypical item shared the largest number of attributes with the other items in the category

• had people list characteristics of objects - chair, desk, apple, banana, etc.
• also list characteristics of superordinate categories - furniture, fruit, etc.
• objects sharing many features with superordinate were better examples of the category (more prototypical)
• superordinate feature lists did not work for all objects - classical view doesn't work
Superordinate-level categories
higher lvl or more general categories; "furniture," "animal," and "tool" are all examples of superordinate-level categories
Basic-level categories
categories that are moderately specific; "chair," "dog," and "screwdriver"
Subordinate-level categories
- lower-lvl or more specific categories; "desk chair," "collie," and "Philips screwdriver"
[1. Basic-level names are used to identify objects]: Rosch & colleagues
• Ask people to look at pictures and identify objects.
• People prefer to use basic-level names.
• People produce basic-level names faster than superordinate or subordinate names.
• When presented with superordinate or subordinate names, people frequently remember the basic-level version when later tested for recall.
• a certain conceptual level is fundamental - basic-level categories
- the role of categorization is to
» group together things that are similar
» distinguish between different groups
» there must be a compromise between these goals
- the members of basic-level categories are
» similar to each other
» dissimilar from other categories
Basic level names
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.
• People produce basic-level names faster than superordinate or subordinate names.
• When presented with superordinate or subordinate names, people frequently remember the basic-level version when later tested for recall.
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.
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.
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
o Emphasizes that your concept of "dog" would include information about numerous examples of dogs you have known
o Prototype approach would argue that your prototype of a dog would be an idealized representation of a dog, w/ avg size for a dog and other features

- individual instances (exemplars) are stored rather than prototype or rule
• match new instance to stored exemplars
- category defined by single best matching exemplar OR - category defined by summed match
- too unconstrained?
• computational models with specific storage and retrieval rules
- a comparison of rule, prototype, and exemplar models (UFO and rain drop)
• Different shape to the decision boundaries in a well defined similarity space
- in concept representation, the examples of a concept stored in memory. A new stimulus is classified by comparing it with these exemplars
-right hemi
(Exemplars and typicality) exemplar approach study: Heit & Barsalou
• seven basic-level categories; provide first example that comes to mind
• categories and examples rated in terms of typicality (by different students)
• Researchers try to create an equation to predict the typicality of the categories based on the exemplars.
• need to take into account the frequency and typicality ratings of the exemplars
• Exemplar frequency and exemplar typicality accurately predicted which of the seven categories were most typical for the superordinate category "animal."
• When asked a question about a category, people don't just consider prototypes, they also include information about less typical examples of the category.
prototype approach
stored representation is a typical member of the category
o suitable when considering a category that has numerous members
• e.g. a prototype may be the most efficient approach for a large category such as "fruit" or "animal
ability to predict a person's performance in another situation, in this case a measure of social sensitivity
exemplar approach
stored representation is a collection of numerous specific members of the category
o ppl don't need to perform any action of abstraction process
o e.g reading the 4 case studies about depressed ppl, you don't need a prototype - an ideal typical person w/ depression. The exemplar approach argues that creating a prototypical person would force you to discard useful, specific data about individual case
network models
• propose a netlike organization of concepts in memory
• many interconnections
• meaning of a concept depends on the concepts to which it is connected
in network models, the representation of each concept, or one unit located w/in the network. When ppl see or hear the name of a concept, the node representing that concept is activated. The activation expands or spreads from that node to the other connected nodes, a process called spreading activation
Characteristic of PDP (2/4):
->> A network contains basic neuron-like units or "nodes," which are connected together so that a specific node has many links to other nodes. PDP theorists argue that most cognitive processes can be explained by the activation of these networks.
Meyer & Schvaneveldt: (relating to words or vocab) lexical decision
- is it a word?
- associated = faster
- short-term semantic priming
• facilitation for
- orthographic/phonemic (bank-->band) - semantic/associative (bread-->butter) - repetition (bread-->bread)
- bilingual (casa-->house)
- mediated (lion-->[tiger]-->stripes)
- etc.
• Dominant explanation: spreading activation theory
Lexical Decision: spreading activation
in network models of semantic memory, the process by which nodes excite nearby or related nodes
- not hierarchical
- not economical
- weighted links and distance
• association strength
• directional links
- how to determine weights and distance?
• Latent Semantic Analysis (LSA)
Characteristic of PDP (3/4):
->>This process of spreading information from one node to other nodes. A concept is represented by the pattern of activity distributed throughout a set of nodes
Latent Semantic Analysis (LSA)
-its scores overlap those of humans on standard vocabulary and subject matter tests, it mimics human word sorting and category judgments, simulates word-word and passage-word lexical priming data and, as reported in Group Papers, accurately estimates passage coherence, learnability of passages by individual students and the quality and quantity of knowledge contained in an essay
Lexical Decision: ACT-R (Adaptive Control of Thought)
this approach uses a series of network models in an attempt to account for a wide variety of tasks including memory, learning, spatial cognition, language, reasoning, problem solving, and decision making
Anderson - a cognitive architecture
exical decision:
- episodic and semantic = declarative (conscious) memory
• consists of propositions
-> e.g., Susan gave a white cat to Maria, who is the president of the club - procedural memory
• actionsequencesandproductionrules - working memory
- ACT-R home page
Declarative knowledge
in semantic memory, knowledge about facts
Propositional network
according to Anderson's ACT-R model, the pattern of interconnected propositions representing a sentence
smallest unit of knowledge that ppl can judge to be either true or false
• Each concept in a proposition can be represented by its own network.
• Practice increases the strength of links between nodes.
• fMRI research examines how changes in learning are reflected in selected regions of the "cortex" and "subcortex"
parallel distributed processing (PDP) approach/also called: connectionism, neural networks
• 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.
• networks rather than specific locations in the brain
(e.g. name, major, year, and political orientation)
Characteristic of PDP (1/4):
- Cognitive processes are based on "parallel" operations, rather than "serial" operations. Therefore, many patterns of activation may be proceeding simultaneously
spontaneous generalization
in (pdp) approach, when information is missing, ppl use individual cases to draw inferences about general info
- In response to the category, exemplars are activated to calculate the general properties of the category
default assignment
In PDP, a method used to fill in missing info about a particular person or object based on info from other similar ppl or objects
—draw a conclusion about a specific member of a category
o E.g. say you meet Christina that's an engineering major, when asked to about her political preference, you have no idea. You make an assumption based on political leaning about engineers to suggest she is conservative
connection weights
in PDP, a characteristic of neural networks that determines "how much activation one unit can pass on to another unit". As you learn more info, the values of these weights will change
->>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).
->>Every new piece of information you learn will change the strength of connections among relevant units by adjusting the connection weights.
graceful degradation
The brain's ability to provide partial memory
- Unlike a computer that will crash if a single bit is out of place, PDP models still work after removing some neurons
E.g. tip-of-the-tongue phenomenon, which occurs when you know which target you are seeking, but you cannot retrieve the actual target
generalized knowledge about a situation, an event, or a person
- "a large unit of organized information used for representing concepts, situation, events, and actions in memory"
- for minor details and with time pressure
• People better remember things that are consistent with the _______
- for major salient events
• People better remember things that are inconsistent with the ______
Schema theories
proposes that people encode "generic" info about a situation, then use this information to understand and remember new examples of the schema.
How Schemas Relate to the Themes of This Book
• top-down and bottom-up processing
• heuristic
• active processing
• schemas can lead to errors
• Errors usually make sense within the framework of that schema.
schema therapy
when a clinician and client work together in order to explore the client's core beliefs, and they also create appropriate, more helpful strategies
simple, well-structured sequence of event
-are usually associated w/ a highly familiar activity
o Abstraction, a prototype of a series of events that share an underlying similarity
• restaurant script
• life scripts
are schema that concern a sequence of events
• e.g., "going to a restaurant"
life script
a list of events that person believes would be most important throughout his or her lifetime
Identifying the Script in Advance: Trafimow & Wyer
developed 4 different scripts, describing a familiar sequence of actions, and added "irrelevant info"
• scripts with irrelevant details
• script-identifying event either first or last
• recall events
• Event recall was higher when the script-identifying event was presented first, rather than last
• 4 ways in which schemas & scripts can operate during cognitive processing:
1. during the selection of material to be remembered
2. in boundary extension (when your memory stores a scene)
3. during memory abstraction (when your memory store the meaning, but not the specific details of the material)
4. during memory integration (when your memory forms a well-integrated representation of the material)
Brewer & Treyens:"office schema"
Schemas and Memory Selection:
• recall objects from an office 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 & coauthors: "lecture schema"
lecturer referring to concept form previous lecture, students were not likely to falsely remember events inconsistent w/ the "lecture schema" such as the lecturer dancing across the floor
• We better show better recall material that violates our expectations
o More likely to recall schema-inconsistent material when that material is esp vivid and surprising
Schemas and Memory Selection: Davidson
• read stories describing well-known schemas
• especially likely to recall schema-inconsistent events that interrupted the normal, expected story
General Conclusions about Schemas and Memory Selection
1. If the information describes a minor event—and time is limited—people tend to remember information accurately when it is consistent with a schema (e.g., the desk and the chair in the ''office'').
2. If the information describes a minor event—and time is limited—people do not remember information that is inconsistent with the schema (e.g., the wine bottle and the picnic basket).
3. People seldom create a completely false memory for a lengthy event that did not occur (e.g., the lecturer did not dance across the room).
4. When the information describes a major event that is inconsistent with the standard schema, people are likely to remember that event (e.g., the child who crashes into Sarah).
boundary extension
our tendency to remember having viewed a greater portion of a scene than was actually shown
Boundary Extension: Intraub & colleagues
• see photo then draw replica of photo (trashcan, lid)
• Participants consistently produced a sketch that extended the boundaries beyond the view presented in the original photo.
• activate a perceptual schema
relevance in eyewitness testimony situations
Perceptual schemas
- People remember an idealized version of pictures (boundary extension)
(e.g. the trash can, recall task)
a memory process that stores the meaning of a message, rather than the exact words
o E.g. you can probably remember much of the information about the concept "family resemblance," even though you cannot recall any specific sentences in its exact, original form
o The term abstract is too abstract
verbatim memory
word-for-word recall of material presented at an earlier time; the research shows that ppl usually have poor verbatim memory, even after a few minutes after a passage have been presented
(The Constructive Approach) Bransford & Franks
• listen to sentences from several different stories
• recognition test including new items
• People were convinced that they had seen these new items before (false alarm).
• False alarms were particularly likely for complex sentences consistent with the original schema.
• False alarms were unlikely for sentences violating the meaning of the earlier sentences.
false alarm
saying you detect a stimulus that is not there
o ppl were likely to make false alarms when a complex sentence was consistent w/ the original schema
constructive model of memory
People integrate information from individual sentences in order to construct larger ideas; later, they cannot untangle the constructed information from the verbatim sentences
- People falsely recognize combined sentences (demo 8.7)
• Particularly when the combination fits the schema
pragmatic view of memory
proposes that people pay attention to the aspect of a message that is most relevant to their current goals
E.g. knowing when only the gist of a sentence is important and when to pay attn. to the specific wording
- The accuracy of verbatim memory depends on the context
• e.g., better memory when sentences placed in a context that made them sarcastic
Murphy & Shapiro: Insult Study
• read letters from "Samantha" to cousin or boyfriend
• bland vs. sarcastic comments
• recognition test on original, paraphrased, or irrelevant sentences
• 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 verbatim memory for the sarcastic version than for the bland version
memory integration
background knowledge encourages people to take in new information in a schema-consistent fashion
• 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
Participants tended to
• omit material that didn't make sense from their own viewpoint
• shape the story into a more familiar framework
• borrow more heavily from their previous knowledge as time passed before additional recall
[background knowledge encourages people to take in new information in a schema-consistent fashion]
gender stereotypes
widely shared sets of beliefs about the characteristics of females and males
• "The women at the office liked to talk around the water cooler"
• "The women at the office liked to gossip around the water cooler"
• "The women at the office liked to talk sports around the water cooler"
Dunning and Sherman
Explicit Memory Task
• 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
Explicit Memory Task
directly instructs participants to remember information
Implicit Memory Tasks
asks ppl to perform a cogn task that does not directly ask for recall or recognition
• Suppose to discourage ppl from providing socially desirable answers
• Measure of gender stereotypes, they assess ppl's general knowledge about gender in their culture
Event-related potential (ERP) technique
(neuroscience techniques to assess gender stereotypes)
records tiny fluctuation in the brain's electrical activity, in response to a stimulus
• stereotype-consistent sentences vs. stereotype-inconsistent sentences
• change in ERPs for stereotype-inconsistent words, but not for stereotype-consistent words
o E.g. reading sentences "I like my coffee w/ cream and dog" "dog" will change ERP
- can also be used to measure stereotypes
• "The nurse prepared herself for the operation"
• "The nurse prepared himself for the operation"
assessing gender stereotypes: Implicit Association Test (IAT)
based on the principle that people can mentally pair two related words together much more easily than they can pair two unrelated words
- Similar to Stroop effect
- Response conflict used to measure evaluation of groups
• Two different tasks (good/bad words versus group membership)
• Same 2 buttons for both tasks
• Compare consistent to inconsistent mapping
• stereotype-consistent pairings (male/math vs. female/arts)
• stereotype-inconsistent pairings (female/math vs. male/arts)
• Participants responded significantly faster to the stereotype-consistent parings than to the stereotype-inconsistent pairings.
Individual Differences: Country of Residence and Gender Stereotypes [Nosek & coauthors]
• Trends in International Mathematics and Science (TIMS)
• 8th grade females and males in 34 different countries
• compare "male advantage" scores on TIMS test with IAT measure of gender stereotyping
• Countries with the highest measures of gender stereotyping were also more likely to be the countries were males performed better than females in both math and science.
Implicit Concepts
In some situations, concepts are learned without being able to state in words what was learned
- artificial grammar (legal vs. illegal letter strings)
• better at memorizing legal letter strings compared to random (illegal) letter strings
- >this wasn't true if told to look for the rule
• best strategy is to simply memorize exemplars
• this can also be done with speeded motor responses
- nonanalytic concept formation
• artificial language contained hidden attributes
• attributes tested with novel symbol strings
-> people never figured out the rules, but made accurate guesses based on exemplar memory
refers to the logical interpretations and conclusions that were never part of the original stimulus material
o e.g. consider the word balloon. You know its made of a lightweight substance. However, a balloon is unlikely to be created from a hiking boot
episodic memory
contains information about events that happen to us
o implies personal experience, emphasizes when, where, or how this event happened to you
o e.g. "this morning in my Political Science course, I learned that Tegucigalpa is the capital of Honduras"