Chapter 9 - Concepts and Knowledge Flashcards
1- The concept of concepts
Terms
* Categories: items that are grouped together
* Concepts: general knowledge of a category
* Exemplars: individual items in a category
Function
* Concepts are vital to do “the right thing with the right kind of thing”
* They are used to predict outcomes, guide behaviour and for communication
2- Concept organization
Concept organization : Inclusivity
1. Superordinate: Mammal | Fish
2. Basic: Deer, Dog | Trout, Shark
3. Subordinate: Terrier, Spaniel (Dog) | Hammerhead, Great White (Shark)
Cognitive economy
* A balance between simplification and differentiation
* Use the simplest terms that is still meaningful for the situation
- General public “This is an owl”
- Birders ”This is a snowy owl”
“Make everything as simple as possible, but not simpler.” Einstein
Concepts in development and disease
* Child learn basic, superordinate, then subordinate concepts
* Semantic dementia patients can use basic level concepts (dog), becomes impaired as the disease progresses
* Early in the disease, basic level concepts are accessed
- A dog is a dog
* As the disease progresses, use general concepts
- A dog is an animal
A graded concept organization
Dog
Trout
Concepts about concepts
* Generalization is the process of deriving a concept from specific experiences
* Do we follow rules, similarity or explanation to form generalizations?
* Do we retrieve representations of specific past instances or abstracted ideas that transcend these specific experiences ?
Ex: ducks and geese?**
3- Concept learning and representation:
Classic views of concepts (defining features)
The classic approach to concept learning
* Concepts involve forming rules about lists
features
Ex: dog= living, animate, breathes, four legs, fur. But………
* Defining features: are necessary and sufficient for category membership.
* Characteristics features: are those common
but not essential for category membership.
* Feature comparison between encountered
items and list
- Refines what a defining features is for a concept
* Works well for simple concepts, not so much for:
- Complex concepts that are subject to variability (e.g., a fur-less dog)
- Ambiguous concepts: ‘student’; a ‘bachelor’; a ‘hot dog’…is a hot dog a sandwich?
Ex of one way to solve: the cube view
…but doesn’t really cut it
4- Concept learning and representation: Prototype and exemplar views (similarity)
Concepts are represented by similarity
* Concepts are not based on defined features, rather are defined by the resemblance to a collection of features
* Wittgenstein: What is common among the concept ‘Game’?
- There is no single attribute that defines a game rather there is a ‘family resemblance’, some inherent similarity
Fuzzy boundaries
* Items are, more or less, part of a category
* An item can be categorized into more than one category
Ex: a sleigh can be seen as both a toy and a vehicle
Feature list vs networks
From early learning to latent learning
Instead of a list that characterizes a bird for example, network
Similarity: Exemplar & prototype theory
Exemplar of dog= golden, chihuahua, german shepherd….
vs.
Prototype of dog= drawing of golden retriever (in my head)…like what i think of when i imagine the word “dog”
Prototype theory:
* Categories are formed from the overlap of exemplars
- These are extracted from experience
* Each category has an abstracted prototype that is pre-stored in memory
- This represents the most common features with other members
* Items are included in a category network around that prototype
- Similar items are stored closer to the prototype than dissimilar items
Prototype theory Study:
* Participants learned to classify dot patterns that were variants of a prototype
- They did not see this prototype
* Participants classified the studied patterns, new patterns and the prototype into groups
- Worse at classifying new compared to old patterns
- Equally able to classify prototype and old patterns
Prototype theory
* The prototype is an abstracted exemplar
- Other members resemble the prototype
to different degrees
- The more obscure members are farther
away from the prototype in the network
* Typicality effect
- A preference for processing items close
to the prototype
-faster to recognize robin than penguin as bird for example
Ex: for the concept of bird. Prototype (for someone could be)= robin. Closer to prototype= sparrow, canary, dove…aka songbirds. Further away from prototype= peacock, penguin, ostrich…
Category name primes typical exemplars
(ex: fruit)… see image slide 34
The role of context
* Prototype theory treats concepts as context
independent
* Thus, does also not account for how a situation determines concept representation
* Is this a typical musical instrument? (ex: harmonica)
- Differs if you are around a campfire (yes) or at a concert hall (no)
Context affects typicality effect
* Rate the typicality as a member of the category bird
Ex: chicken
If from farm, higher in typicality, if from city, lower in typicality
Exemplar theory (DIFFERENT FROM PROTOTYPE THEORY)
* There is no single abstract prototype for a concept
- Every instance of a category is stored in memory, not a prototype
* To determine if a new item is member of a category:
- Retrieve some or all exemplars of category members
- Compute similarity to new item at the time of concept determination
* Explains how context can influence concept representations
- We use personal experience and situation information to form concepts
at retrieval
Ex: Is this a dog? Let me think of my dog experiences
Multiple forms of representations
* Prototype (yellow, red) versus exemplars (green, blue) engage different brain networks
* To meet different task demands
- Specificity task – exemplar; generalized task - prototype
* Holding multiple representations supports flexible thought
5- Concept learning and representation: Knowledge views (explanation and essentialism)
Knowledge-based theories
* Explanation rather than similarity-based view of concept categorization
* Implicit intuitive knowledge used
- This is a fruit because I find it fruit-like
* Essentialism: The idea that certain categories have an underlying reality or true nature that one cannot observe
6- An alternate embodied cognition view of concepts and the brain
An embodied view of concepts
* Concepts are accessed as a function of the environment and current goals
* Concepts are processed in different brain networks, and shift depending on what is being accessed from a concept
Facilitating Goals: Ad-hoc categories
Think as many items as possible that belong to this category:
“Things that can catch on fire”
* A category concept that is invented for a specific purpose or goal
* Bringing together dissimilar members into a single temporary category to meet a goal
* Related to creativity
ADHD, knowledge and creativity
White et al., 2018
Conceptual expansion, a process of thinking
outside traditional conceptual boundaries
Ex: fruit for another planet (Non-ADHD vs. ADHD people)
Embodiment and the brain
* Knowledge is stored as sensorimotor neural representations
* The particular representation that is accessed as a function of what
sensorimotor domain is required
Perceptual symbols system
* Perception and concepts knowledge are linked as ‘perceptual symbols’
* Activating a concept will engage certain sensory-perceptions to engage mental simulation as a function of the goals of the
current task
* Property verification tasks
* People are faster to respond if a previous trial asked about a feature
from the same percept
* We recruit concepts based on senses/perceptions
Ex: faster to verify “loud” as a property for “blender” if it followed the trial that asked if “rustling” was a part of “leaves” (percept match trial (sound)), compared to if question about loudness of a blender followed a trial asking if “green” was a part of “apple” (non-percept match trial (visual and sound)).
Brain representations
* In an MRI scanner, participants passively read action words (pick, kick, lick)
* The brain region that process movements associated with those words were active
during passive reading
Neuropsychological case studies
* Brain injury cases of people with category specific deficits
- Some have selective impairment in naming living things
Ex: can’t name animals correctly (a giraffe is called a kangaroo for example), but can name fruit/vegetables and artifacts correctly (non-living).
- Some have selective impairment in naming non-living things
Loss of concept depends on brain damage
TP= persons deficit, IT=animals deficit, IT+=tools deficit
Sensory functional theories
* Concepts represented by defining
feature of that concept
- Living things are defined by visual
features (a moose has antlers)
- Inanimate objects (tools) are defined
by functional features (a pencil is to write)
