course overview what is ai? what are the major challenges? what are the main techniques? where...
TRANSCRIPT
Course Overview What is AI?
What are the Major Challenges?
What are the Main Techniques?
Where are we failing, and why?
Step back and look at the Science
Step back and look at the History of AI
What are the Major Schools of Thought?
What of the Future?
Part I:Introduce you to
what’s happening in Artificial Intelligence
Part II:Give you an
appreciation for the big picture
Why it is a grand challenge
Done
Course Overview What is AI?
What are the Major Challenges?
What are the Main Techniques?
Where are we failing, and why?
Step back and look at the Science
Step back and look at the History of AI
What are the Major Schools of Thought?
What of the Future?
Part I:Introduce you to
what’s happening in Artificial Intelligence
Part II:Give you an
appreciation for the big picture
Why it is a grand challenge
Done
Course Overview What is AI?
What are the Major Challenges?
What are the Main Techniques?
Where are we failing, and why?
Step back and look at the Science
Step back and look at the History of AI
What are the Major Schools of Thought?
What of the Future?
Looking at the Science Engineering vs. Science Introduction to Cognitive Science Cognitive Psychology 1 Cognitive Psychology 2 Cognitive Development Linguistics Neuroscience Philosophy
Course Overview What is AI?
What are the Major Challenges?
What are the Main Techniques?
Where are we failing, and why?
Step back and look at the Science
Step back and look at the History of AI
What are the Major Schools of Thought?
What of the Future?
Looking at the Science Engineering vs. Science Introduction to Cognitive Science Cognitive Psychology 1 Cognitive Psychology 2 Cognitive Development Linguistics Neuroscience Philosophy
Language Module Specialised module in the brain?
What other evidence could support Chomsky’s hypothesis?
Neuroimaging can’t pinpoint a single area Many different areas involved in different aspects of
language Some areas seem to serve a number of different functions
Modular processing could still exist within a functional module Functionally specialised neural circuits A combination of components
some special to language, others more general
Language Module Evidence…
People with damaged “language module”, but other cognitive abilities ok Damage in Broca’s area in the left hemisphere
– can be unable to produce or perceive language with complicated grammar
People with limited cognitive abilities, but “language module” ok Williams Syndrome
– severe mental deficits, but grammatical language
Many recent results/theories contradict this
Damage in Wernicke's area – specialised language skill areas Poor comprehension Speech has a natural-sounding rhythm and normal syntax …but no recognisable meaning (fluent or jargon aphasia)
Specific language impairment – 6% of population Not related to or caused by other developmental disorders Difficulty with inflected forms of words, "-ed"
Alternative: language processed in general cognitive system
No clear consensus yet… grammar localised… words not
Can Chimpanzees Learn Sign Language? Washoe was trained for sign “More” Learned sign for toothbrush by imitation Made up some novel combinations of words:
refrigerator = OPEN FOOD DRINK
Some criticisms of results
Tried to replicate results with Nim Chimpsky, failed Learnt some signs, but no grammar Learnt nothing that could not be taught to a pigeon
Much controversy about these studies Some claim it was self deception Example (Pinker): Researchers said chimp was making a sign
Native human signer said he was just scratching himself
Can Chimpanzees Learn Sign Language?
Can Chimpanzees Learn Sign Language?
No
Recommended Reading
Sapir-Whorf Hypothesis Language's nature influences the habitual thought of its
speakers. Hopi language
Western languages : the present and future are thought of as "places“ Time is a path linking them "three days" equivalent to "three apples", or "three kilometres“ Native American languages oriented towards process
Inuit people Numerous words for snow Modifies the world view of the Eskimo Creates a different mode of existence for them Geoffrey Pullum: "The great Eskimo vocabulary hoax“
Language of the Pirahã tribe of Brazil Contains three counting words: one, two and many. Pirahã people have difficulty recounting numbers > 3 Controversy: maybe Pirahã have no need to practice doing so
Sapir-Whorf Hypothesis Strong form of hypothesis: language determines thought
Popular in fiction: Orwell’s 1984 newspeak, e.g. no freedom Generally not accepted nowadays But some weaker elements may be present
Different languages categorise the world in different ways In English:
The dog ran through the forest The dog ran through the table(!)
In English the table is more thought of as its top Other languages think of it more as its legs
Classifiers and Categories
George Lakoff book: Women, Fire and Dangerous Things Dyirbal language
I - most animate objects, men II - women, water, fire, violence, and exceptional animals III - edible fruit and vegetables IV - miscellaneous (everything else)
Metaphors Argument is war
Your claims are indefensible He attacked every weak point in my argument His criticisms were right on target I demolished his argument I’ve never won an argument with him You disagree? Okay, shoot. If you use that strategy he’ll wipe you out. He shot down all of my arguments.
Metaphors Time is a resource
You’re wasting my time This gadget will save you hours I don’t have the time to give you How do you spend your time these days? That flat tire cost me an hour I’ve invested a lot of time in her I don’t have enough time to spare for that You’re running out of time Do you have much time left? He’s living on borrowed time Thank you for your time I lost a lot of time when I got sick
Metaphors The conduit metaphor
Ideas are objects Language expressions are containers Communication is sending
Examples It’s hard to get that idea across to him I gave you that idea Your reasons came through to us It’s difficult to put my ideas into words His words carry little meaning Your words are hollow The idea is buried in terribly dense paragraphs
MetaphorsUp is positive, down is negative
He is at the peak of health He came down with flu His health is declining I am on top of the situation He is at the height of his power His power rose He fell from power The stock is rising We are at an all-time low
Metaphors Personification
Life has cheated me His religion tells him he cannot drink wine The Michelson-Morley experiment gave birth to a new physical theory Cancer finally caught up with him Inflation has attacked the foundations of our economy Inflation is eating up our profits Inflation has robbed me of my savings Inflation has outwitted the best economic minds in the country
…inflation is an adversary Declare war on inflation Call for sacrifices Install a new chain of command
Metaphors Lakoff’s Thesis:
cognition is depends on the linguistic metaphor
We are completely immersed in metaphors There seems to be no way to say some things without metaphors
Course Overview What is AI?
What are the Major Challenges?
What are the Main Techniques?
Where are we failing, and why?
Step back and look at the Science
Step back and look at the History of AI
What are the Major Schools of Thought?
What of the Future?
Looking at the Science Engineering vs. Science Introduction to Cognitive Science Cognitive Psychology 1 Cognitive Psychology 2 Cognitive Development Linguistics Neuroscience Philosophy