Chapter 9: Knowledge (Cognitive Psychology Quiz)

Lexical Decision Task

subjects read stimuli, some of which are words and some of which are not words. Their task is to indicate as quickly as possible whether each entry is a word or a nonword.

crowding

which refers to the fact that animals tend to share many properties (like eyes, legs, and the ability to move

sensory-functional (S-F) hypothesis

which states that our ability to differentiate living things and artifacts (non living things) depends on a semantic memory system that distinguishes sensory attributes and a system that distinguishes function.

Olaf Hauk: Link Between Perceptual and Motor Responses Study

who measured subjects' brain activity using fMRI under two conditions: (1) as subjects moved their right or left foot, left or right index finger, or tongue; (2) as subjects read "action words" such as kick (foot action), pick (finger or hand action), or lick (tongue action). Results -area of he cortex activated by actual movements and by reading the action words semantic somatotopy- words related to specific parts of the body and the location of brain activity

semantic somatotopy

words related to specific parts of the body and the location of brain activity

conceptual knowledge

—knowledge that enables us to recognize objects and events and to make inferences about their properties

exemplar approach

- involves determining whether an object is similar to other objects - the standard for the exemplar approach involves many examples, each one called an exemplar.

Jeremy Wilmer: Face Recognition Study in Twins

-Jeremy Wilmer and coworkers (2010) tested the idea that areas of the brain are innately specialized for specific categories of concepts by measuring face recognition ability in monozygotic (identical) and dizygotic (fraternal) twins. Their finding that the correlation of scores between identical twins was more than twice as high as the correlation for fraternal twins (0.70 vs. 0.29) led them to conclude that there is a genetic basis for the mechanisms that support face recognition

Rosch: Priming Experiment

-Priming occurs when presentation of one stimulus facilitates the response to another stimulus that usually follows closely in time -Subjects first heard the prime, which was the name of a color, such as "green." Two seconds later they saw a pair of colors side by side and indicated, by pressing a key as quickly as possible, whether the two colors were the same or different. Results: - The most important result occurred for the two "same" groups. In this condition, priming resulted in faster "same" judgments for the prototypical (good) colors (reaction time, RT = 610 ms) than for the nonprototypical (poor) colors (RT = 780 ms). Thus, when subjects heard the word green , they judged two patches of primary green as being the same more rapidly than two patches of light green -the results of the priming experiments support the idea that subjects create images of prototypes in response to color names

back propagation

-The learning process occurs when the erroneous responses in the property units cause an error signal to be sent back through the network -The error signals that are sent back to the hidden units and the representation units provide information about how the connection weights should be adjusted so that the correct property units will be activated. Ex: A young child is watching a robin sitting on a branch, when suddenly the robin flies away. This simple observation, which strengthens the association between "robin" and can fly , would involve activation. But if the child were to see a canary and say "robin," the child's parent might correct her and say "That is a canary" and "Robins have red breasts." The information provided by the parent is similar to the idea of feedback provided by back propagation.

Paul Hoffman and Matthew Lambon Ralph: Multi-Factor Approach Study

-The subjects' task was to rate each item on the features -For example for the concept door, the subject would be asked "how much do you associate door with a particular color?" -Subjects rated their answer Results -indicate that animals were more highly associated with motion and color compared to artifacts, and artifacts were more highly associated with performed actions

James Tanaka and Marjorie Taylor: Expert Experiment

-They asked bird experts and nonexperts to name pictures of objects. There were objects from many different categories (tools, clothing, flowers, etc.), but Tanaka and Taylor were interested in how the subjects responded to the four bird pictures. Results -show that the experts responded by specifying the birds' species (robin, sparrow, jay, or cardinal), but the nonexperts responded by saying "bird." Apparently the experts had learned to pay attention to features of birds that nonexperts were unaware of. Thus, in order to fully understand how people categorize objects, we need to consider not only the properties of the objects but also the learning and experience of the people perceiving those objects

exemplar

-are actual members of the category that a person has encountered in the past. Thus, if a person has encountered sparrows, robins, and blue jays in the past, each of these would be an exemplar for the category "birds."

Warrington and Shallice: Sensory Functional Hypothesis Study

-patients with brain damage are unable to name animals but were able to name nonanimals (artifacts) Results -Performance on a naming task for patients K.C. and E.W., both of whom had category-specific memory impairment. They were able to correctly name pictures of nonliving things (such as car and table) and fruits and vegetables (such as tomato and pear), but performed poorly when asked to name pictures of animals.

Eleanor Rosch: Categories Experiment

-proposed that the "typical" prototype is based on an average of members of a category that are commonly experienced. For example, the prototype for the category "birds" might be based on some of the birds you usually see, such as sparrows, robins, and blue jays, but doesn't necessarily look exactly like any one of them. Thus, the prototype is not an actual member of the category but is an "average" representation of the category -presented subjects with a category title, such as "bird" or "furniture," and a list of about 50 members of the category. The subjects' task was to rate the extent to which each member represented the category title on a 7-point scale, with a rating of 1 meaning that the member is a very good example of what the category is, and a rating of 7 meaning that the member fits poorly within the category or is not a member at all. Results -The 1.18 rating for sparrow reflects the fact that most people consider a sparrow to be a good example of a bird (high typicality) -The 4.53 rating for penguin and 6.15 rating for bat reflect the fact that penguins and bats are not considered good examples of birds (low typicality)

concepts

-the mental representation of a class or individual and the meaning of objects, events, and abstract ideas ex: to express this in concrete terms, we can say that the concept "cat" is the answer to the question "What is a cat?" If your answer is that a cat is an animal that is furry, meows, moves, and eats mice, you will have described your concept of "cat"

mirror neurons

-the neuron's response to watching the experimenter grasp an object is similar to the response that occurs when the monkey is performing the action itself which is why its called mirror neurons -Vittorio Gallese and coworkers (1996) were investigating how neurons in the monkey's premotor cortex fired as the monkey performed actions such as picking up a toy or a piece of food. As they were recording from neurons while the monkey carried out specific actions, they observed something they didn't expect: Some neurons in the monkey's premotor cortex fired both when the monkey grasped food on a tray and when the monkey observed the experimenter grasping food on a tray

typicality effect

-this ability to judge highly protypicality objects more rapidily

Edward Smith: Sentence Verfication Technique Experiment

-used a procedure called the sentence verification technique to determine how rapidly people could answer questions about an object's category. - The procedure for the sentence verification technique is simple. Subjects are presented with statements and are asked to answer "yes" if they think the statement is true and "no" if they think it isn't. Results: -found that subjects responded faster for objects that are high in prototypicality (like apple for the category "fruit") than they did for objects that are low in prototypicality (like pomegranate) -this ability to judge highly protypicality objects more rapidily is called the typicality effect

graceful degradation

Disruption of performance due to damage to a system that occurs only gradually as parts of the system are damaged. It is similar to what often happens in actual cases of brain damage, in which damage to the brain causes only a partial loss of functioning.

David Meyer and Roger Schvaneveldt: Lexical Decision Task (Association)

Lexical Decison Task: subjects read stimuli, some of which are words and some of which are not words. Their task is to indicate as quickly as possible whether each entry is a word or a nonword. Meyer and Schvaneveldt used a variation of the lexical decision task by presenting subjects with pairs of words, one above the other The subjects' task was to press, as quickly as possible, the "yes" key when both items were words or the "no" key when at least one item in the pair was a nonword. The key variable in this experiment was the association between the pairs of real words. Results -was that reaction time was faster when the two words were associated. Meyer and Schvaneveldt proposed that this might have occurred because retrieving one word from memory triggered a spread of activation to other nearby locations in a network. Because more activation would spread to words that were related, the response to the related words was faster than the response to unrelated words.

Gorana Probic: Stimulating the Anterior Temporal Lobe

Presented pictures of living things and artifacts to subjects and measured the response time for naming each picture. They then repeated this procedure while TMS (transcranial magnetic stimulation) was being applied either to the ATL or to an area in the parietal lobe that is normally activated when a person is manipulating an object Results Red bars indicate response time before TMS stimulation; blue bars are response times during stimulation. Stars above pairs of bars indicate that there is a significant difference between the bars. TMS stimulation of the ATL affected subjects' speed of naming equally for artifacts and living things (left graph). Stimulation of the parietal cortex caused an increase in speed of naming only for artifacts

Rosch and Mervis: Prototypicality and Family Resemblance Study

Rosch and Mer vis's (1975) instruc tions were as follows: For each of the following common objects, list as many characteristics and attributes as you can that you feel are common to these objects. For example, common characteristics for bicycles are two wheels, pedals, handlebars, you ride on them, they don't use fuel, and so on. Give yourself about a minute to write down the characteristics for each of the following items: 1. chair 2. sofa 3. mirror 4. telephone If you responded like Rosch and Mervis's subjects, you assigned many of the same characteristics to chair and sofa. For example, chairs and sofas share the characteristics of having legs, having backs, you sit on them, they can have cushions, and so on. When an item's characteristics have a large amount of overlap with the characteristics of many other items in a category, this means that the family resemblance of these items is high. Little overlap with other members of a category means the family resemblance is low. Results -Rosch and Mervis concluded from their results that there is a strong relationship between family resemblance and prototypicality.

Other Rosch Experiments About Basic Level

Rosch and coworkers (1976) did a similar experiment, they found that people tended to pick a basic level name. They said guitar (basic level) rather than musical instrument (global) or rock guitar (specific), fish rather than animal or trout , and pants rather than clothing or jeans . In another experiment, Rosch and coworkers showed subjects a category label, such as car or vehicle , and then, after a brief delay, presented a picture. The subjects' task was to indicate, as rapidly as possible, whether the picture was a member of the category. The results showed that they accomplished this task more rapidly for basic level categories (such as car) than for global level categories (such as vehicle). Thus, they would respond "yes" more rapidly when the picture of an automobile was preceded by the word car than when the picture was preceded by the word vehicle

Collins and Quillian's Network Model

The network consists of nodes that are connected by links. Each node represents a category or concept, and concepts are placed in the network so that related concepts are connected. In addition, a number of properties are indicated for each concept.The links connecting the concepts indicate that they are related to each other in the mind. This is a hierarchical model because it consists of levels arranged so that more specific concepts, such as "canary" and "salmon," are at the bottom, and more general concepts are at higher levels.

Rosch's Approach About Basic Level Categories

There are different levels of categories: 1) global level 2)basic level 3)specific level , For the following categories, list as many features as you can that would be common to all or most of the objects in the category. For example, for "table" you might list "has legs." 1. furniture 2. table 3. kitchen table If you responded like the subjects in the Rosch and coworkers' (1976) experiment, who were given the same task, you listed only a few features that were common to all furniture, but many features that were shared by all tables and by all kitchen tables. Rosch's subjects listed an average of 3 common features for the global level category "furniture," 9 for basic level categories such as "table," and 10.3 for specific level categories such as "kitchen table" Overall Idea Rosch proposed that the basic level is psychologically special because going above it (to global) results in a large loss of information and going below it (to specific) results in little gain of information

family resemblance

Things in a category resemble each other in a number of ways

hierarchical organization

This kind of organization, in which larger, more general categories are divided into smaller, more specific categories, creating a number of levels of categories

cognitive economy

This way of storing shared properties just once at a higher-level node

family resemblance

Wittgenstein proposed this idea to deal with the problem that definitions often do not include all members of a category. -things in a particular category resemble one another in a number of ways

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

category-specific memory impairment

an impairment in which they had lost the ability to identify one type of object but retained the ability to identify other types of objects.

Connectionism

approach to creating computer models for representing cognitive processes -also called parallel distributed processing (PDP) models because, as we will see shortly, they propose that concepts are represented by activity that is distributed across a network.

hub and spoke model

areas of the brain that are associated with specific functions are connected to the anterior temporal lobe (ATL), which serves as a hub that integrates the information from these areas. Evidence supporting this idea is that damage to one of the specialized brain areas (the spokes) can cause specific deficits, such as an inability to identify artifacts, but damage to the ATL (the hub) causes general deficits, as in semantic dementia

semantic network approach

concepts are arranged in networks

connection weight (connectionist network)

determines how signals sent from one unit either increase or decrease the activity of the next unit

category

includes all possible examples of a particular concept. ex: the category "cats" includes tabbies, Siamese cats, Persian cats, wildcats, leopards, and so on

prototype approach to categorization

membership in a category is determined by comparing the object to a prototype that represents the category

semantic category approach

proposes that there are specific neural circuits in the brain for some specific categories.

multi-factor approach

searching for more factors that determine how concepts are divided up within a category. Ex: We can appreciate this approach by posing the following question: Assume that we start with a large number of items selected from lists of different types of animals, plants, and artifacts. If you wanted to arrange them in terms of how similar they are to each other, how would you do it? You could arrange them by shape, but then items like a pencil, a screwdriver, a person's finger, and a breakfast sausage might be grouped together. Or considering just color, you could end up placing fir trees, leprechauns, and Kermit the Frog together. While it is true that members of specific categories do share similar perceptual attributes, it is also clear that we need to use more than just one or two features when grouping objects in terms of similarity.

embodied approach

states that our knowledge of concepts is based on reactivation of sensory and motor processes that occur when we interact with the object.

semantic dementia

that causes a general loss of knowledge for all concepts -the anterior temporal lobe is damaged in these patients

categorization

the process by which things are placed in categories.

transcranial magnetic stimulation (TMS)

the use of strong magnets to briefly interrupt normal brain activity as a way to study brain regions

prototype

typical member of the category

input unit (connectionist network)

units activated by stimuli from the environment

Connectionist Network (Basic)

units- represented by circles lines- represent connections that transfer information between the units input units- units activated by stimuli from the environment , input units send signals to hidden units, which send signals to output units connection weight- connection weight determines how signals sent from one unit either increase or decrease the activity of the next unit

definitional approach to categorization

we can decide whether something is a member of a category by determining whether a particular object meets the definition of the category.