Talking heads!4/10. Easy and hard problems Artificial intelligence Turing test Loebner prize The real thing: human language comprehension. Overview of comprehension. Overview of comprehension. Vast database. lexicon.
Easy and hard problems
The real thing: human language comprehension
Reference and co-reference
Significant aspects of meaning come from the context of the utterance. These include deictic words (e.g. now, this, here) and other pronouns, as well immediately preceding conversation in “working memory.”
Gaps and traces (Pinker, p.219;482)
The policeman saw the boy that the crowd at the party accused (TRACE) of the crime.
Example 1 can be interpreted as a relative (2) or complement clause (3)
1. “ The fact that Otto knew was surprising.”
2. “The fact that Otto knew () was surprising.” (Otto knew some fact that was surprising. Note the gap in 2 but not in 3 below.)
3.”(The fact) that Otto knew was surprising.” (A complement clause names explicitly the surprising fact, namely “that Otto knew (something) was surprising.”
Multiple gaps allow multiple interpretations
“The girl that Bill wanted () to leave () wore a blue dress.”
Is “that” coreferent with the first or second gap -- the subject or object of leave?
Compare “The girl that Bill wanted () to leave Sam wore a blue dress.”
When did the boy say () that he hurt () himself?
What do you think Cookie Monster eats ()?
You think Cookie Monster eats (what)?
*What do you think what's in here?
Packaging several propositions (sentences) into one sentence increases complexity of processing.
The most extreme case is:
The player kicked the ball kicked him.
The player (that was) thrown the ball kicked him.
The player kicked the ball (that was) thrown him.
Kemper et al (1997) report low idea density predicts Alzheimers disease decades before other symptoms!.Complex sentences “idea density” 2
Inference -- going beyond the given propositions -- is part of comprehension.
Pinker: She: “I’m leaving.” He: “Who is he?”
“In 1950, I was the tallest kid in sixth grade.”
Some inferences are “presuppositions” -- implicit statements assumed true by speaker and inferred by listener.
“Bill knows that the world is flat.”
“When did you stop drinking?”
“Her gift is too tall for her bedroom.”
She fell off the first/top rung of the ladder. (primes ok/dead)
Our brain tends to activate likely consequences as it comprehends LVast database 2.5 - inferences from anywhere based on the semantic interpretation of the sentence
“sportugese” - Sportsfans predict scores from verbs better than non-fans? No kidding!
“Lakers crush Celtics” “Celtics hold off Timberwolves”
What is the margin of victory?
"The procedure is actually quite simple. First you arrange things into different groups depending on their makeup. Of course one pile may be sufficient depending on how much there is to do. If you have to go somewhere else due to lack of facilities that is the next step, otherwise you are pretty well set. It is important not to overdo any particular endeavor. That is, it may not seem important, but complications from doing too many can easily arise. A mistake can be expensive as well....."“vast database” 3.5
For most of us, this is a parsable text, using known words, but with little overall meaning unless we were given a title "Washing Clothes." Then it becomes meaningful and much more memorable as Bransford and Johnson, (1972) demonstrated.
Bransford, J. D., & Johnson, M. K. (1972). Contextual prerequisites for understanding: Some investigations of comprehension and recall. Journal of Verbal Learning and Verbal Behavior, 61, 717-726.
The LH does much of the language processing in comprehension. However there is some suggestion the RH gives a unique perspective.
Using similar materials, with and without titles, St George et al (1999) show differential hemisphere involvement -- the RH working hardest when there are no titles.
The listener’s perception of the purpose of the utterance influences one’s interpretation of it.
"I now see that my husband was simply engaging the world in a way that many men do: as an individual in a hierarchical social order in which he was either one-up or one-down… conversations are negotiations. Life is a contest, a struggle to preserve independence and avoid failure..
I, on the other hand, was approaching the world as many women do: as an individual in a network of connections.. conversations are negotiations for closeness… they try to protect themselves from others' attempts to push them away.." p.331 712 notes. (Deborah Tannen, 1990)