M2 Lecture 13 Flashcards
define Categories
The systematic grouping of instances that are similar
Categories: The systematic grouping of instances that are similar ¤ Different theories on how this grouping occurs
¤ Theories tend to follow what idea
the idea of cognitive economy
what is the idea of cognitive economy
¤ A balance between simplification and differentiation with categorization ¤ Use the fewest ‘bits’ of information to store a category but still ensure a
category can distinguish between things
define Concepts
The knowledge associated with a category
Conceptual knowledge is used to:
¤ Make predictions about our environment ¤ Identify new instances of categories
¤ If it walks like a duck, and talks like a duck …
what is the function of categorizing
allows is to do “the right thing with the right kind of thing
¤Provides material for thoughts
¤The basis of communication
¤Language categories
¤Generalizations to guides behavior and make predictions
¤Stereotypes as social concepts gone wrong
Categories are boundaries between what
collections of instances/members
what are the types of categories
¤ Between-category separation
¤ Within-category compression
what is Within-category compression
¤ Members of the same category look more similar
what is ¤ Between-category separation
¤ Members of different categories
look more distinct
How do we learn concepts?
Rule based approaches
Probability based approaches
what are the Rule based approaches
Concepts are collections of necessary and sufficient features
related to a category
what are the Probability based approaches
¤Concepts and categories are formed through experience ¤The prototype theory
according to a rule based approach, Concepts are made up of what
attributes
what are attributes
Attributes are features of a concept
¤ These can take on different values
¤ Attributes are expressed as different values by category members
according to a rule based approach, Learning a concept involves what
forming rules and testing them
¤ We form hypotheses about the combination of attributes that define a concept
¤ We actively test and refine these hypotheses
what are the Types of concepts
¤ Conjunctive concept
¤ Disjunctive concept
¤ Relational concept
what is Conjunctive concept
¤ Concepts that contain conjunctions of attributes (AND) ¤ A Mother is defined as a female AND having a child
what is Disjunctive concept
¤ Concepts where two or more possible sets of attributes (Either-or
concepts)
¤ Fame can be defined in different ways
what is Relational concept
¤ Concepts defined by a relation between attributes ¤ Marriage is defined by the link between two people
what are the different Rule-based instances
positive
negative
abstraction
what is Positive instance:
An example of a particular concept
¤ Criterial attribute
¤ An attribute that must be present for a positive instance
¤ Wings of a bird
what is Negative instance:
An example that does NOT contain the right attributes of a particular concept
what is Abstraction
What we do to determine which attributes to include and exclude when forming concept rules
¤ Most typical of the concept
explain the experiment that tested how we learn concepts
¤Tested how we learn conjunctive concepts
¤ Two attributes must be present
¤ E.g. A card with a black (AND) square
¤Reception task
¤ Participants are shown cards (instance) from a deck in a pre-arranged order
¤ They indicate if they think a card is part of the concept
¤ Experimenter tells them if they are correct
¤Selection task
¤ Participants pick a card (instance) from the deck
¤ Experimenter tells them if it is a positive instance of the concept they are to learn
Selection tasks: Forming rules what is this
Form rules of a concept to guide how to pick instances
what is Conservative focusing
¤ When you encounter a positive instance
¤ Focus on one attribute of this instance to create a rule
¤ ‘Test’ this rule on new instances
¤ Select instances that vary only on this attribute
what is Focus gambling
¤ When you encounter a positive instance
¤ Focuses on all the attributes of this instance to create a
¤ Select new instances that have all these attributes
¤ Quick results if positive instances comes soon after forming rule
what are the subsections of forming rules
conservative focus and focus gambling
what is Simultaneous scanning
¤ Start with all hypotheses about the concept
¤ Attempt to eliminate as many as possible with each instance ¤ Elimination strategy
what is Successive scanning
¤ Form a single hypothesis about the concept ¤ Test it by selecting instances until it is false ¤ Stab in the dark approachSuccessive scanning
¤ Form a single hypothesis about the concept ¤ Test it by selecting instances until it is false ¤ Stab in the dark approach
Rule based approaches: Some issues
There are not always explicit rules to define a concept in the real-world ¤ But some concepts don’t have explicit rules
¤ The concept ‘student’ or a ‘bachelor’?
We don’t always explicitly test these rules ¤ Some concepts are learned implicitly
¤ Language learning (we will come back to this in a later lecture)
Category membership has very defined boundaries with a rule-based approach ¤ There is complexity of concepts in real world
¤ Some concepts are ‘kind of’ part of a category
are boundaries very clearn
nope– pretty fuzzy
Items can belong to different categories
Membership to a category is a matter of degree
what is Prototype theory of category learning
¤ An approach that is not rule-based
¤ States that concepts are formed by how we interact with our environment and information
¤ Conceptual knowledge and categories are by a ‘more or less’ principle
do Concepts have rules or a ‘single essence’ or collection of features
no
Concepts are better understood as clusters of what
attributes
¤ No one ‘thing’ to define a concept
do attributes need to present in all
concept category members
no
All members resemble each other in some way
We use similarities between things rather than what to figure out a concept
explicit rules
what is Prototype theory
¤ Categories formed from the overlap of concepts exemplars
¤ This happens through experience and comparing to what we
know
¤ Each category has a member that is a prototype
¤ Items are included in a category around that prototype via resemblance
¤ There is no requirement that a property or set of properties are shared by all members
¤ there are no criterial attributes
what is the ‘cleanest’ example of a categoty
The prototype is the ‘cleanest’ example of a category
¤ It is at the center of your representation of a category
what is The ‘Typicality’ effect
A preference for processing prototypical items compared to more obscure category members
(you would recognize a morning dove as a bird faster than a penguin as a bird)
what can prime prototypical items more than non-prototypical items
category names
can prototypes change
yes over time
how do The levels of concepts work
General to specific
We favor the what level of
concepts
basic
¤ How we naturally speak
¤ Reflects cognitive economy
¤ A behavioral advantage for classifying at the basic level
¤ Children learn concepts at a basic level first
what are the Parallels in development and loss
¤ Preservation of general relative to specific information in semantic dementia (SD)
¤ Controls and SD patients asked to classify items at specific level (golden retriever), basic level (dog), general level (animals)
¤ Early on, basic category level information is spared and general level information is impaired
¤ A dog is a dog but not an animal
¤ As disease progresses, the reverse pattern is seen
¤ A dog is an animal and not a dog
what is The levels of concepts: Graded structure
¤ Distinguishes between concepts at the same level of inclusiveness
¤ Represents how well a member represents a concept
¤ Some members are better examples than others
what determines concepts
our culture
¤ There is stability in the prototype structure across people from the same culture
what are the Problems with prototypes
¤Does not account for how context can determine a concept
Is a harmonica a musical instrument?
depends on where you are
what is the Embodied view of concepts
¤ Concepts are formed to facilitate interaction with the environment
¤ Concepts make use of sensory-motor, emotional, and social cognition capacities of our body-brain system
what are Ad-hoc categories
¤A category invented for a specific purpose, particular occasion or goal
¤Similar characteristics (e.g., graded structure) to other basic prototype categories
¤Indicates we can use concepts flexibly
¤ Think creatively
explain the experiment about Concepts and creativity
¤ Participants completed tests of creativity ¤ Split into low and high creative people
¤ Participants then did a free association task (generate as many concepts to a term)
¤ These data were used to create semantic ‘concept’ networks for each person ¤ High creative ability was linked to broader and flexible concept networks
what was the experiment that tested if Do gestures affect the way people mentally represent concepts?
1.Learn the Tower of Hanoi Test
¤ Move disks from one peg to another
2.Explain and perform gestures of the solution
3.Re-do the Tower of Hanoi Test with a set that matched or mismatched gestures
¤ Given disks of same weights from (1) OR disk of different weights (now gestures do not match)
what was the result of the Tower of Hanoi experiment (where they had to move the blocks)
If gestures did not matched how to solve the second trial of the Tower of Hanoi (i.e., the disks were heavier), performance was impaired
¤ People ‘stored’ their solutions in the gestures used to describe them
¤ Gesturing grounds people’s mental representations in action
what is Embodiment
- Simulationisimportantforconceptualprocessing
2. Conceptual knowledge is stored as sensorimotor representations in the brain
what is the Perceptual symbols system
Rejects the notion that concepts are amodal (abstract)
according to the Perceptual symbols system, Perception and concept formation work together explain
¤ We store the knowledge of a concept across our senses
¤ ‘Perceptual symbols’are reflected in the way we use our brains to retrieve knowledge
according to the Perceptual symbols system, Activating a concept will do what
ge senses/perceptions to simulate the concept based on goals of the current task
¤ What we need to know
what was the experiment about Perceptual symbols system
¤ Property verification tasks: verify if the perceptual property fits with the object/concept
¤ People are faster if a previous trial was in the same modality (sense) ¤ Evidence that we recruit concept attributes based on senses/perceptions
In an MRI scanner, participants passively read action words: pick, kick, lick that relate to hand, foot and mouth activities
what happened in the brain
The corresponding body part brain region was activated during passive reading of the concepts
Ballet and Capoeira dancers viewed ballet and capoeira dances in an fMRI scanner what happened in the brain
There was more activity in movement areas (premotor cortex) when viewing dances
for which they were experts
¤ Acquired motor concepts affected brain activity
¤ Experts can simulate movement concepts they are familiar with
what are Mirror Neurons
Neurons that fire when we perform an action and observe that action in others
mirror neurons were first discovered where
in monkey
¤ Electrodes in prefrontal cortex that control hand/mouth actions
¤ Recorded activity when monkeys reached for food
¤ Recorded activity when the monkeys observed a person pick up food ¤ Found overlap in neural activity
Observed actions stimulates the same neurons that would fire when that action is produced
do Different areas of the brain process different concepts
yes
what are two examples of Brain injury cases of people with category specific deficits
¤ Some have selective impairment in naming living things
¤ Some have selective impairment in naming non-living things
what is Category specific brain injury
¤ Selective impairment of naming non-living things
¤ Two individuals with large left-hemisphere strokes
¤ Picture matching tasks: point to the picture, in an array, that corresponds to a spoken word
what are Sensory functional theories
There is no ‘ abstract module’ for concepts
¤ Knowledge of a specific category will be supported by sensory or motor areas of the brain
how do Sensory functional theories explain different concepts
Different concepts are supported by different cognitive processes
because of attribute importance
¤ Living things – visual features
¤ Inanimate objects – functional features
give a summary of this lecture
¤ Classical approach to concept formation
¤ Rule-based concept formation tasks and strategies
¤ Prototype views of concept formation
¤ Concepts can be meaningfully divided among three levels of inclusiveness
¤ superordinate, basic, and subordinate ¤ Concepts have a graded structure
¤ some members are better examples than other
¤ Embodied nature of cognition
¤ Our mind is linked to our bodies
¤ A bridge between goals and environmental possibilities
¤ Perceptual symbol systems
¤ We simulate conceptual knowledge
¤ Concepts are sensory and functional representations in our brain
According to prototype theory's organization of concepts, the labels animal, dog, beagle, correspond respectively to which sequence of levels of inclusivity? A) Basic, superordinate, subordinate B) Subordinate, superordinate, basic C) Subordinate, basic, superordinate D) Superordinate, basic, subordinate
D) Superordinate, basic, subordinate
