What is a network computational architecture? How does it differ from a serial computational architecture? What advantages does this provide for understanding cognition?
Network - multiple things can be processed at the same time
Might be mutually reinforcing
Resembles what brain might do
Serial - one thing happens after another
How do symbolic networks differ from connectionist networks?
Each node represents a conceptLinks and connections are relational - network encodes propositions
Neurons that fire together wire together
Develop connections that are either excitatory or inhibitory - connections don’t mean anything themselves
How are two-layer connectionist networks limited (I.e., what sorts of concepts can’t they capture)?
Can’t learn when similar inputs don’t map onto similar outputs
Exclusive (OR) cannot be learned
Explain the difference between localist and distributed representations in a connectionist network.
Localist - one unit per concept
Nodes are concepts
Connections are not symbolic
Advantage - very clear; know what’s going on
Disadvantage - every concept needs separate unit
Can’t generalize because you’ve learned something for that particular concept
Nodes are subsymbolic
Takes a whole collection of nodes to represent 1 concept
Connections are not symbolic
Representations emerge from learning and constraints
What are PDP networks good at? (Be able to deﬁne and/or give examples for 5 traits)
Allows for more concepts
Network can make predictions depending on similar inputs
Can be activated by different features
Some things can positively and negatively affect total number (to threshold)
Auto-associators (have generalizations from features to features; reconstructive, content-addressable memory; graceful degradation; simultaneous constraint satisfaction; generalization - go beyond inputs; learning from example)
What are PDP networks not good at? (Be able to deﬁne and/or give examples for 5 traits)
Differentiating different individuals
Two birds vs. one big bird - identical twins
Barack beat Mitt. vs Mitt. beat Barack
Crisp category boundaries
3 vs. 257
What is content addressable memory? Are symbolic variables content addressable? Why or Why not?
Information is not retrieved by knowing a (content-less) address, but instead by using some of the content as a cue to retrieve the remainder of the information
Symbols are not content addressable - in order to activate a concept, you have to already know features of the concept
What is dead reckoning? Why does Gallistel argue it requires symbolic representations? What evidence exists that ants and bees can dead reckon?
Dead reckoning - no features on environment, figure out how you’ve moved and accelerated and figure out where you are relative to starting location
Leaves nest to go on foraging journey; finds food and takes it back to nest
Takes a reading of sun and figure out how far they’ve gone from the reading
Ant has to store 2 variables: distance and angle from nest
Requires cognitive mapping (symbol-processing)
Why and how do bees dance?
Dance to communicate where they are and where they’ve been
Circle (waggle dance when you make figure 8 short enough that it becomes a circle)
Waggle - angle tells what direction according to position of sun
Duration of dance and number of vibrations = distance
Communicate distance, direction, and quality of a resource
Seem to be representing certain things symbolically
Can also remember angles and distances between multiple sources of food
What is a cognitive map? What evidence is there that insects and humans use a cognitive map to navigate?
Cognitive map - a mental encoding of the relative spatial positions of goals and landmarks
Bees keep track of allocentric angles (between locations they are not at currently) when planning foraging trips
What type of information is most influential when a human reorients? What's the evidence?
Humans can combine landmark info with geometry
Be able to understand the results and implications of Wang & Simons (1998).
Had people look at circular table with objects on it in particular arrangement
People closed their eyes and moved or stayed in same place while turning table
Moved one object
Given new viewpoint, did an object move and where?
People did better when the table position was the same
True or false: our ability to use maps to navigate is a cultural invention?
Munduruku - can still use maps (at American children level)
Maps = intrinsic
What is subitizing? What creatures do it? What's the evidence? What would happen if a person/animal were unable to subitize?
Subitizing - counting small groups of things very rapidly (breaks down at about 4 items)
Animals and humans
Children and box
Crackers hidden in box; child reaches in box and grabs one at a time
Will reach into the box the same number of times they see crackers going into a box
Keeping track of number of objects
Hide eggplants in box and they watch
Look at looking times of monkeys and see if they are surprised by number of eggplants hidden in box after reveal
If unable to subitize, have to count even small numbers of things
Estimating abilities are intact
What is estimating? What creatures do it? What's the evidence? What would happen if a person/animal were unable to estimate?
Estimation - ability to recognize amounts of things roughly when they exceed 3-4
Present in animals, children, and adults
Macaque monkey brains
Fixate on dot; see array of dots, see nothing, given one of several possibilities
Either sees complete match or not
Has to say whether it's a match or not
How does language affect numerical cognition? What's the evidence?
Subitizing - distinct from language or math
Counting - requires language
Frank et al 2008; 2012
English speaking people were fine unless they had to do a verbal distraction task
What are naturally occurring animal communication systems like? How do they differ from human language?
Communicate thru displays and calls
Usually finite in number
Each display has a holistic meaning, can't be recombined to mean something new
Humans an re-assign sounds to different meanings
Can't combine sounds like we can
Limited, finite vocabulary
Aren't learned; typically innate
Human languages are learned to a certain extent
To what extent can animals acquire human communication systems? How are they limited?
Able to learn words and use them appropriately
Had trouble recombining words
Seemed like he was communicating thoughts, but when comparing Nim to children, number of terms he used were very constant
Something that is particularly human is necessary in learning human language
Define and characterize the advantages of arbitrariness and discreteness.
Actual signs in language are arbitrarily associated with the thing
The sounds themselves are randomly mapped to some meaning
Opposite of iconicity
Makes referring and abstract concepts possible
Made up of whole bits as opposed to continuous bits
Need to add whole words up in order to make up sentence; need whole sound in order to make up word
Allows us to combine units in predictable ways which can give ways to novel meanings
Allows you to break out of combinatorial system
What are the basic levels of linguistic representation? What type of rules govern each level of representation?
Phonology - rules for sound combinations
Formation rules - what are possible sound sequences in a language?
Adjustment rules - how sounds are altered in context
Morphology - how words are formed
Applying things like past tense to made-up words
Rules determine grammatical acceptability
Two main aspects:
Phrase - group of words that act together as a grammatical unit
What's the difference between descriptive and prescriptive rules? Provide examples. "Fantast-fucking-ic"
Descriptive rules - describe how you use language
More that what grammar teachers can teach but less than you can explain
We know where to put things even though we weren't explicitly taught the words (fantast-fucking-ic)
Prescriptive rules - prescribe what you ought to do (who vs. whom)
Given a sentence, what is the subject and what is the predicate?
Subject = noun phrase
Predicate = verb phrase
Provide evidence that sentences have internal structure above and beyond being ordered strings of words
Structural ambiguity - the only thing that differs is their phrase structure
What evidence is there that sign languages operate like spoken languages?
Structural ambiguity - the only thing that differs is their phrase structure
Signs = arbitrary
Different signs depending on origin of sign language
Distinctive features: configurations
Distinctive features: location
What is induction?
Induction - figuring out a rule based on a finite set of examples
Trying to generate rules for things we've never seen before
What kinds of evidence are theoretically available for learning novel concepts? In what situations is each kind of information most useful? Which is more important for language acquisition?
Evidence that an utterance is well-formed
Over 99% of the input is grammatical
Evidence that an utterance is not grammatical
Why do children babble?
Experimenting with the mouth and sound formation
How does the learning trajectory of language production and comprehension abilities of children differ?
Children know much more than they say
Bottlenecks in production - children have trouble pronouncing certain strings of phonemes
Recognize only the sound distinctions that are important to their native language by 1 year
Children understand words as early as 9 months
Some knowledge of word order by 18 months
How does the child's knowledge of language sounds develop? What's the evidence?
Initial state - prepared for all the languages of the world
Organized around an initial set of pre-linguistic categories
Extremely plastic, responsive to environmental language
How do words and syntax develop?
At birth, infants can discriminate:
Mother's voice from another woman
Dr. Seuss story read during pregnancy from another story
Native language relative to another language only if they differ in rhythmic properties
Syntactic Comprehension - "Look, Big Bird is tickling Cookie Monster"
What learning takes place in the womb? How do we know?
Sound travels through tissue and fluid
Particularly low frequencies
Babies identify certain aspects of their native language even immediately after birth
What evidence suggests that children are born with an innate capacity for language?
Born recognizing the distinctions that are important in any language in the world
Lose ability to distinguish sounds that are not important to their native language
Shifting of sound distinction, not addition
Describe 3 functions that concepts serve for cognition. Illustrate each with an example.
Classification: ability to take two things and say that they are the same type
Understanding/explanation: why a thing is as it is
Prediction: we know how it's going to behave in the future
Reasoning: can use knowledge of category to draw inference on this category
Communication: allows us to convey knowledge that allows someone else to do all these things without them having to learn it themselves
Give an example of how mental concepts might contribute to stereotyping.
People underestimate differences within a group and enhance differences between groups
The presence of a category is:
Driving apart - people make bigger disparities between categories
Driving together units in one category
Negative traits assigned to other group, positive traits assigned to their group
What is a basic level concept? What's the evidence for it? Why is there a basic level organization?
Natural level for naming
Cross-cultural consistency - first words are usually basic level
Share both parts and shape
Biggest grouping for which there are lots of shared features
What is the classical theory of concepts? Name 3 problems with this view. Illustrate with examples.
Bundles of necessary and sufficient features
Triangle - enclosed polygon with 3 straight sides
Bachelor - unmarried, adult, human, male
Bird - has wings, lays eggs
All or none
Hard to come up with proper definitions for categories (not inclusive enough)
Definitions not exclusive enough either
Which properties are really atomic?
Tough to come up with a set of features for many categories
Most categories are not all or none
What characterizes probabilistic theories? Describe two pieces of experimental evidence that support them.
Categories organized around typical, not defining, properties, or features
Category membership is graded
Some members are better than others
Category boundaries are fuzzy
What evidence is there for prototype organization of concepts?
Ideal is a prototype
Input is matched against prototype
"Central tendency" extracted from multiple experiences
Prediction - equal or better performance for ideal than for actually experienced examples
Subjects learned to classify dot patterns formed by distorting prototypes
What are Armstrong et al.'s main arguments against probabilistic theories?
We can reason absolutely with all or none categories, even if they act graded sometimes
Some mentally stored identification function used to sort things quickly, and also a mentally categorial description of the category that determines membership in it
Describe Armstrong's dual position theory. What is the Theory Based Theory of concepts? How does it work differently for natural kinds and artifacts? Give examples. Be able to recognize examples of different theories in action and to explain them.
Dual aspect of concepts
Core description - definitional = compositionality (how wholes get meanings from their parts)
Identification procedure - probabilistic
Be able to recognize examples of different theories in actions and to explain them.
What you store in memory is central tendency
Ideal exemplar of tendency (bird -> robin, not penguin)
Think of all the examples and store them simultaneously
Any additional token is compared to all your experiences
Average relationship with any token
What is induction? Why is it a puzzle for cognition?
Drawing a general conclusion from specific facts or observations
No answer is sure to be right, only more probable
What is the difference between a normative and a descriptive theory? What is the normative theory of induction?
Normative accounts - how we ought to reason
Choose outcome that gives you the right probability of success
Descriptive accounts - what we actually do
What's a heuristic? Why do humans reason using heuristic strategies?
Rule of thumb or strategy for problem solving
Faster; gives you the right answer most of the time
Tendency for people to favor information that confirms their preconceptions or hypotheses regardless of whether the information is true
The easier it is to come up with an example of something, the higher likelihood you're going to give it
Over-reliance on small numbers, regression to the mean (base rate neglect, conjunction fallacy, gambler's fallacy)
Law of small numbers
Judgmental bias which occurs when it is assumed that the characteristics of a sample population can be estimated from a small number of observations or data points
Base rate neglect
If presented with related base rate information and specific information, the mind tends to ignore the former and focus on the latter
What the two kinds of information are critical in reasoning about the likelihood of an event given some evidence? Which do people tend to ignore in their judgments?
Diagnostic information - likelihood of the data given a hypothesis
People don’t consider the base rate - prior likelihood of the hypothesis
Describe two reasons why heuristical reasoning is typically sufﬁcient for our purposes.
Gives right answer most of the time
Describe one way to get people to pay attention to base rates. Illustrate with an example.
If chance is highlighted, performance improves
If 100 pieces of paper with thumbnail sketches, 70 lawyers and 30 engineers
Provide two examples of the inﬂuence of unconscious reasoning on conscious decisions.
HM and the tower of Hanoi
Moving the disks is part of unconscious memory
HM kept on getting better at it even though he doesn’t remember seeing the same
Korsakoff’s and learned aversion
Vitamin D deficiency that leads to problems similar to HM’s
Could still learn implicit things
What is the “products vs. processes” theory of the conscious/unconscious distinction? What evidence militates for and against this hypothesis?
What’s your mother’s name?
Remember and retrieve
Aware of product, not process
Theeuwes, Kramer, Hahn, Irwin
Had people look at array of objects on screen that initially started grey w/ an s in them
At some point, a circle with red appear
New circle also appeared in the array that was also red
People say they didn’t see addition of circle; eye movements tell another story
Just as many fixation to original red circle and the new red circle
Problem with products vs processes theory
What are the differences between an automatic and a controlled process? How can a process become automatic?
Things that you don’t need to consciously allocate attention to
Things you don’t have to do - naming a color
Happens with intention
Learning to make something automatic
Trained people to read an essay and later answer questions about the essay
At the same time they were reading, were taking dictation
Through headphones, the person is hearing a list of words and is asked to write them down
Initially, this task is impossible
After months of practice, they get so rehearsed at taking dictation after reading that when they took a test, they did just as well as people without the audio
Dictation task - people were unaware of it; happened below level of conscious awareness
What are the advantages and disadvantages of the conscious/unconscious distinction?
Unconsciousness - advantages
Efficiency - automatic things are shunted off to automatic system
Other things need to be flexible; information that’s useful at one level might not be useful at another level
Errors of introspection
Errors of automaticity
What is Dehaene’s neuronal workspace hypothesis of conscious awareness? What are the three ways that a stimulus might be processed from this perspective? What are the neuronal and cognitive consequences of each?
3-way distinction in terms of phenomena and awareness: subliminal, preconscious, and conscious
2 things are necessary for you to be conscious of something:
Subliminal - if weak or interrupted, there isn’t much activity
Subliminal - if there’s no top-down, not going to get any real effect that is reportable at all
Subliminal - short-lived priming
Can have facilitation of processing of a familiar stimulus
Doesn’t really seem to change things fundamentally
Low-level inputs bottom-up
Sufficiently strong to reach conscious
Top-down controlled-attention towards stimulus
Might not be directing top-down attention towards stimulus activity; don’t get reportability
Card trick/gorilla - could notice if you were orienting towards them, but you’re not
What are the easy problems of consciousness according to Chalmers?
Some kinds of information in the brain are accessible - perceived objects: actions, contents of sentences
Others are not - transforming retinal image, muscle movements, rules of syntax
What are the hard problems of consciousness?
Can’t reduce consciousness to particular number of neurons
Inherently subjective; can’t study it in the same way as we normally do
Principle of structural coherence
Things you are aware of are the only things you can have phenomenal awareness of - have qualia associated with them
Same fxnal organization - same kind of conscious experiences
Some information has 2 aspects - physical system, phenomenal aspect that is subjectively reportable
Sentience makes no difference to anything; therefore it is an illusion
The fact that you are aware of something = illusion
Problem 1: Descartes’ disproof
The only thing we can be sure of is our thoughts
There’s still a you, and the only way you know that is because of your thoughts
Problem 2: why shouldn’t we hurt people?
Pain = byproduct of something; not real
Problem 1: How?
Problem 2: Panpsychism
Everything you come across has some informational properties in some way; do they all have some degree of subjective awareness?
Neural Reductionism (sentience)
The brain secretes consciousness
Only possible with organic material
Problem 1: How?
Problem 2: Rules out sentient robots and aliens that aren’t made of same matter as us before we’ve even seen them