Langston, Cognitive Psychology, Notes 12 -- Language--Meaning
I.  Goals:
A.  Where we are/themes.
B.  Literal.
C.  Inferences.
D.  Figurative Language.
E.  Pragmatics.
F.  Readers’ knowledge.
G.  Working memory revisited.
H.  Outline of a basic discourse model.
I.  Mental models.
J.  Wrap-up.
II.  Where we are/themes.  I have two goals for this lecture:
Meaning:  When we talk about the “meaning” of a sentence, it can actually be represented at multiple levels.  What we'll do is look at the kinds of information represented at each level.  We'll start with literal.  Then we'll talk about going a little beyond literal by adding information to the representation.  Then we'll go way beyond literal by looking at figurative language (the meaning is different from the words).  Finally, we'll talk about pragmatics (the meaning isn't in the words at all).
Understanding text.  When we're through with meaning, we're going to move on to talk about extracting the meaning from texts.  What do we have to talk about?  We have to extract the information, we have to make some sort of representation, and we have to hook up the ideas in that representation.  We need to store that away so we can recall it later, and we need to elaborate it with inferences.
What you're going to see will look a lot like two lectures piled together.  That's because it is.  The theme of this unit is to take all of the work we've done and integrate it to understand an interesting question.
Meaning:  What is the meaning of a sentence?  This is a hard concept to define, and a hard concept to study.  To make it less complicated, I'm going to divide it into four parts. 
III.  Literal meaning.  This is what the sentence is about in the strictest sense.  This kind of meaning can be broken down as well.
A.  Verbatim meaning:  Basically, memorize the text.  You don't process it or try to understand it, just memorize it.  This type of meaning representation is very poor.  In some contexts this is all you have to rely on, so you will see people form verbatim representations.  Usually, this is only used for rote memorization.  If you think about the Star Spangled Banner (if you happen to know it) the meaning isn't really what you're reciting, it's the words, cued one from the other like a behaviorist sentence.  The things whose meaning you understand aren't usually remembered word-for-word.
B.  Deep structure:  It's a fact that people remember the gist of what they read better than the exact words.  One idea for what the gist might be is to remember deep structures as in transformational grammar.  So, if you hear “Alice plays the tuba” you remember something like “Alice play tuba”, and if you hear “The tuba was played by Alice you remember “Alice play tuba + passive”.  The “+ passive” part refers to the fact that the sentence you heard was in the passive voice, otherwise, you couldn't tell that from the representation.  There's evidence that when you have people recall sentences, they generally forget transformations more than meaning.  We saw a little of this last time.
C.  Propositional representation.  Propositions are like the idea units in a text.  For example, the structure of “The professor delivers the boring lecture” would include:
P1:  Exists(professor)
P2:  Exists(lecture)
P3:  Boring(P2)
P4:  Deliver(P1, P2)
We'll see a more formal propositional system a little later.
1.  That you go beyond verbatim representation:
Sachs (1967) presented a story about telescopes.  During reading, if you test immediately after a sentence, people recognize changes in the surface structure of the sentences as readily as changes in meaning.  After 80 syllables, however, people recognize changes in meaning, but not changes in surface structure.  Sentence (1) below is the original.  After 80 syllables, (1) - (3) are all recognized at about the same percentage.
    (1)  He sent a letter about it to Galileo, the great Italian scientist.
    (2)  He sent Galileo, the great Italian scientist, a letter about it.
    (3)  A letter about it was sent to Galileo, the great Italian scientist.
    (4)  Galileo, the great Italian scientist, sent him a letter about it.
This finding is usually interpreted as demonstrating that you retain the basic ideas more than the exact words.
2.  That you have propositions:
Many studies show that what people forget from sentences tend to be whole propositions.  Furthermore, varying the number of propositions per sentence is a much more effective way of increasing the difficulty of a text than varying the number of words. 
IV.  Inferences.  Inferences go beyond literal meaning by adding something to the representation of the text that wasn't in the text.  To see what an inference is, try the demonstration.
Demonstration:  Read these two sentences.  To understand how they relate, you have to make an inference along the lines of “riding a bike is a way to lose weight.”  In general, making inferences is so easy that you probably don't even know you're doing it.
    (5)  Diane wanted to lose some weight.
    (6)  She went to the garage to find her bike.
I'll present a scheme for classifying inferences along four dimensions.
A.  Logical vs. pragmatic inferences:  Some inferences are guaranteed to be correct (if you form them).  So, if you hear “Todd has six apples, he gave three to Susan”, it's safe to infer that Todd has three apples (logical inference).  On the other hand, some inferences are likely, but not guaranteed (pragmatic).  So if you hear “Todd dropped the egg”, you don't know for sure that it broke (but it probably did).
B.  Forward vs. backward:  Some inferences are made in advance.  For example, if you hear “John pounded the nail” and infer “John used a hammer,” it's forward.  Other inferences are made about past things.  For example, if you read “John pounded the nail.  The handle broke and he smashed his thumb,” you need to infer “hammer” to figure out what handle broke.  Backward inferences are generally called bridging because they build a bridge between two parts of the text to explain how you get from one to the other.  Forward inferences are usually elaborative because they elaborate on the text but aren't strictly necessary.
C.  Type of inference:  There are five types here:
1.  Case-filling:  In your case-role grammar you can infer parts that are missing.  For example, if you hear “Father carved the turkey” you can fill in the instrument (like knife).
2.  Event-structure:  If you read “The actress fell from the 14th floor balcony” you might infer the consequence (she died).  Or, you might infer a cause (she slipped).  These are things that flesh out the structure of an event.
3.  Parts:  If I say “Carol entered the room.  The X was dirty”, you might infer “the room has an X.”  Usually, these are required to make sense of a text.  For example, if you read “He poured the tea and burned his hand on the handle” you need to infer a teapot handle to make sense of it.
4.  Script:  People have scripts for prototypical event-sequences (like going to a restaurant).  Script inferences are when they fill in missing events with items from the script.
5.  Spatial/temporal:  You can infer relationships between items in a text.  For example, if I say “B is to the left of A”, you might infer “A is to the right of B.”
D.  Implicational probability:  How strongly is the inference implied by the text.  Some things are much more likely than others.  For example, floors are more likely in rooms than chandeliers.
When we look at our model of understanding we'll see that inferences have a major role to play. 
V.  Figurative language.  The meaning is completely different from the words used to convey it.  I'll just list some of the more common types.
A.  Metaphor:  “John is a pig”  You know John isn't actually a pig, the meaning somehow relates features of pigs to features of John.
B.  Idioms:  “Spill the beans.”  It's like a conventionalized metaphor.  In terms of comprehension, it's treated like a big word.  For example, “spill the beans” = “tell a secret.”
C.  Metonymy:  “Washington and the Kremlin are finally talking.”  Let some aspect stand for the whole.  For example, we let the fact that the US government is in Washington stand for the whole government.
D.  Colloquial tautologies:  “Boys will be boys.”  It's a kind of metonymy where some feature is highlighted.  It's usually negative (as in “business is business”), but for objects it's also indulgent.  So, you'll hear “boys will be boys”, but not “rapists will be rapists.”
E.  Irony/sarcasm:  The words are used to express a situation that's actually opposite from the words.  For example, if someone's lounging on the couch and you come in and say “Boy, you're working hard.”
Figurative language represents a special case for reading, because we have to get from one set of words to a different set of meanings.  How it's done is an interesting challenge for our methodology. 
VI.  Pragmatics.  Speaker and hearers' background beliefs, understanding of the context, and knowledge of the way language is used to communicate.  Note that none of this stuff is literally in the message.  Consider:
    (7)  The councilors refused the marchers a parade permit because they feared violence. (who fears?)
    (8)  The councilors refused the marchers a parade permit because they advocated violence. (who advocates?)
The information about who fears and who advocates comes more from your knowledge about councilors and marchers, not as much from the sentence.
I'm going to lump a lot of diverse language activities under this umbrella for want of a better place to put them.  The thing they have in common is that the meaning is derived as much from external factors as from the message.
A.  Presuppositions:  An assumption or belief is implied by the choice of a particular word.  Consider:
    (9)  Have you stopped exercising regularly?
    (10)  Have you tried exercising regularly?
“Stopped” implies that you used to exercise, “tried” implies that you don't exercise.  It's possible that in some contexts this will even lead to a person being insulted.
B.  Speech acts:  The effect of the message is different from its literal content.  There are 3 parts:
1.  The locutionary act:  The utterance.
2.  The illocutionary act:  What's intended by the speaker.
3.  The perlocutionary act:  The effect.
If I said “Can you shut the blinds?”:  L = “Are you able to shut the blinds?”, I = “Please shut the blinds”, P = someone shuts the blinds.
Speech acts can take numerous forms:
1.  Statement:  “There's a bear behind you.”
2.  Command:  “Run!”
3.  Yes/No question:  “Did you know there's a bear behind you?”
4.  Wh- question:  “What's that bear doing in here?”
The form can have an impact on the perlocutionary act.
Understanding:  What does it mean to understand?  Again, hard to say.  Try this demonstration.
Demonstration:  Read the two passages.  One should seem easy to understand, one should be hard.  By the end of this unit, we should be on our way to quantifying why that is.
"Weighing less than three pounds, the human brain in its natural state resembles nothing so much as a soft, wrinkled walnut.  Yet despite this inauspicious appearance, the human brain can store more information than all the libraries in the world.  It is also responsible for our most primitive urges, our loftiest ideals, the way we think, even the reason why, on occasion, we don't think, but act instead.  The workings of an organ capable of creating Hamlet, the Bill of Rights, and Hiroshima remain deeply mysterious."
"On the other hand, there may be portions of this task which can be formulated without reference to numerical relationships, i.e. in purely logical terms.  Thus certain qualitative principles involving physiological response or nonresponse can be stated without recourse to numbers by merely stating qualitatively under what combinations of circumstances certain events are to take place and under what combinations they are not desired."
As we do this unit, we'll focus on readers’ knowledge, because what you already know is a big influence on what you understand.  Then, we'll look at a model of understanding to see how it might work.  There will be several parts to that. 
VII.  Readers’ knowledge.  You have a lot of world knowledge that you can bring to bear when reading.  That knowledge will greatly influence how well you understand the text.  One type of knowledge is script knowledge.  For a lot of overlearned event sequences, you know what typically happens.  We talked about going to the doctor's office before.  When you're trying to understand a story, one thing you're doing is matching it to a script.  If you know a lot about doctors, you can fill in details from the story to improve comprehension.  You can also use the script to help you remember the story later.  There are also scehmas.  These are knowledge structures.  For example, you should be developing a cognitive psychology schema.  How can these affect comprehension?
A.  A prior context is one way to improve comprehension.  Basically, knowing which script (or schema) to apply will help you understand.

Demonstration:  One of these passages follows a typical script, one follows a schema.  Read this passage.  Brief retention interval.  Write down all you recall.  Memory should be poor.  Now, the title is “suppressed so my demonstration works.”  Recall.  Does it help?  Try reading it again with the title.  Recall.  Does it help?
A second try:  Half get “title suppressed” half don't.  Everyone read the passage and recall.  Who gets more?
What usually happens is that prior context helps with memory because it gives you a way to organize the information.  Without a context, it's very hard to make sense of the texts, and memory is poor.
B.  A problem is:  If all you're doing is remembering the script, how do you tell individual events apart?  An easy answer is that you usually don't.  What did you have for breakfast a year ago today?  Most people have no idea how to answer this question.  In experiments, people will frequently “remember” things that are typical of a script, but not in the text they read.
Demonstration:  Half the people read about Guy 1, half read about Guy 2.  After a longish retention interval, the Guy 2 people are more likely to falsely recognize sentences about Guy 2 than the Guy 1 people.
Half the people read about Guy 1, half read about Guy 2.  Then, after a week, they were asked to recognize statements.  The Guy 2 group was more likely to falsely recognize statements like “sorry, it's a secret.”  The point is that when recalling, prior knowledge is integrated with what you are learning.  To the extent you have prior knowledge, reading isn't all that hard.  When the knowledge is missing, reading gets tougher.
C.  It's not just scripts and prior context that can provide the necessary knowledge to make a text comprehensible.
Demonstration:  Read this passage.  Now, try it with the picture.  It should make more sense and be easier to remember.
The point of this section so far is clear.  If you have something to use as the foundation of your representation, good.  If not, it's hard.  Some of the material for this class should present you with these kinds of problems because of a lack of prior knowledge. 
VIII.  Working memory revisited.  As you've probably noticed, working memory plays a big role in almost every model of comprehension, at every level.  How does it affect language comprehension?  It acts as a limit on how much you can hold at once.
When you get an item that you want to include, you have to gather some activation (akin to “mental energy”) that you can use to represent it.  Putting something in working memory takes mental effort.  If you don't work at it, it won't happen.  Unfortunately, the amount of mental energy that you have at your disposal is fixed (when we talk about working memory capacity, that's the capacity).
Let's say you're processing this sample of text:
The plate is on the table.
The spoon is left of the plate.
The fork is behind the spoon.
The cup is right of the fork.
Let's further assume that your working memory capacity is three things (plus processing load).  (This will make more sense if you follow along with the figure.)  When you get the first proposition, you can give it all of your storage capacity.  When the next proposition comes in, you have to steal some activation to represent it.  So, they both get in, but they're each half as strong as the first one was.  Then the third proposition comes in.  You steal some more activation, and put it in.
When the fourth proposition comes along, you're out of juice.  Now, when you steal activation, something has to go.

Working memory
Working memory limitations are a driving force behind theories of language comprehension.  Last time we discussed parsing strategies like late-closure to ease the burden.  The models of understanding also have working memory limitations. 
IX.  Outline of a basic discourse model.  The basic problem in text comprehension is that the meaning of a text is more than the meanings of its sentences.  Somehow, you have to connect information in the sentences into a coherent structure that is the “meaning” of the text.  The Kintsch and vanDijk (1978) model illustrates all of the basic parts of this process.
A.  There are four main steps in comprehending texts.  They are:
1.  Turn the text into propositions.  There's a fully developed system for this.  Here's an example of a basic proposition, just to get the flavor:


The parts:
a.  P1:  This is the proposition number.  Propositions can be embedded in propositions, as in (P2  (TIME:IN P1 YESTERDAY)).  The numbering system acts as an embedding shorthand.
b.  WANTS:  A relation.  The word is in all caps to indicate that it's a concept, not a word.  So, propositions are supposed to be in the “language of thought,” not tied to a particular language.  WANTS could just as easily be AS1295D.
c.  JOAN APPLE:  Arguments.  These are what the relation is about.  Some relations need two arguments, some need just one.  The number of arguments is based on the same considerations we discussed when we talked about verbs and cases.  It's unusual to say “I gave” because “give” normally requires an object to be given.
The first step is to take an entire text and turn it into propositions.
2.  Arrange the propositions into a text base:  An organized representation of the text (but only a local representation, meaning it covers relationships between ideas that are close together).  It will look a lot like our phrase markers from last week, but we're connecting concepts and not syntactic categories.
Some propositions appear more often (they're important to the story so they stay in working memory).
3.  Use world knowledge to form global concepts (akin to identifying the main ideas).
4.  Form a macrostructure:  The relationships between the units in the text base.  Essentially, connect the smaller trees into a super-tree.  World knowledge helps a lot with this as well.
Demonstration:  To illustrate these concepts, look at these samples of text.  The one that's locally and globally consistent should be easy to understand because you can connect each new sentence to an old sentence, and there's a global structure.  The one that's locally inconsistent stays on a topic, but connecting each sentence is hard because inferences are required.  The last one is easy to do locally, but has a problem in its macrostructure.  In general local problems are harder for readers than global problems.  In fact, readers usually don't notice global problems.  The model takes this into account.

Locally and globally consistent
George wanted to run in a marathon.
Running requires a lot of energy, and this energy can come from carbohydrates.
Spaghetti has a lot of carbohydrates, so George learned how to make spaghetti.
Eating spaghetti helped George have the energy he needed to finish the marathon.
Locally inconsistent
Diane wanted to lose some weight.
She went to the garage to find her bike.
Diane's bike was broken and she couldn't afford a new one.
She went to the grocery store to buy grapefruit and yogurt.
Globally inconsistent
Tammy was standing inside the health spa waiting for her friend.
She had just completed an exhausting workout.
Tammy's workout usually included a half hour of aerobics and an hour of weight training.
Today, Tammy had doubled her aerobics time.
Tammy saw her friend and went into the health spa to greet her.
B.  Some additional notes on the model:
1.  Readability is characterized by properties of the text and properties of the reader.  For example, if the text is well constructed, but your memory is low, then you'll have a hard time building structures.  Or, if the text is poor, but memory is high, you'll still struggle.
2.  How do they test this model?  They present the passages to the model and look at its memory.  The model's recall of a text is based on how often a proposition was held over in working memory, how related propositions are to one another, how easy it was to form structures, etc.
They also present these passages to human participants and look at their recall.  If people tend to remember similar propositions in a similar order, that's evidence that the model is using a similar process.
3.  This model has all the parts:
a.  Levels of representation (we talked about this in the last unit).
b.  Limited working memory capacity.
c.  Strategies to choose what to remember.
d.  Influences of readers’ knowledge. 
X.  Mental models.  So far, our readers are extracting propositions, building local structures, identifying topics, and making global structures.  Is there anything else going on?  Yes.  In addition to all of this, readers are forming mental models of the events in a text.  A mental model is a representation of what the text is about, not the text itself.  So, it goes beyond propositions (a representation of the text).
A.  Where is it?  Remember that we talked about divisions in working memory, and two main branches.  You have an articulatory loop and a visuo-spatial scratchpad.  The loop holds auditory information (either from hearing speech or recoding written text).  The sketchpad is for images, processing pictures, and doing spatial things like moving your eyes across the page and processing visual features of text.  It's not so much a place as a kind of mental energy devoted to spatial processing.  All of the stuff we've discussed so far goes on in the loop, the mental model is in the sketchpad.
B.  What do I mean by a model?  Read the first two sentences about turtles and logs.  They both describe the same situation.  If you read the first one and I give you the second one to verify, what will happen?  Now, look at the second two.  They describe different situations.  If I give you the first one and ask you to verify the second one, what will happen?
    (11)  Three turtles rested on a floating log and a fish swam beneath them.
    (12)  Three turtles rested on a floating log and a fish swam beneath it.
    (13)  Three turtles rested beside a floating log and a fish swam beneath them.
    (14)  Three turtles rested beside a floating log and a fish swam beneath it.
The difference in terms of propositions is very slight.  In fact, the difference that distinguishes the sentences in the two situations is the same.  So, there must be some additional level of representation that explains this.  That's the mental model.
C.  What do mental models do?  One thing is keep information foregrounded (show you that it's with the topic and should remain in working memory).  Glenberg, Meyer, and Lindem (1987) demonstrated this.  People read texts like this sample.  At some point, they saw a word and had to say if that word was in the text.  The trick was that the item could sometimes be associated with the main character (so it goes where the main character goes) and other times dissociated (the character goes somewhere, the item stays behind).  Associated items should stay foregrounded because they might come up again.  Dissociated items can usually be forgotten safely.  A demonstration of this experiment is available on my software page.
If readers are forming a mental model, then associated items would be near the character in the model, and dissociated items would be far away.  Being near should facilitate responding to the test.
If you look at the graph of the data, you can see that that happens.  Associated items are more readily available after a one sentence delay than dissociated items. 
XI.  Wrap-up.  What we've done is looked at how all of our cognitive psychology tools could be brought to bear on understanding what you read and defining the meaning of what you read.  Obviously, there's still more to it.  But, this gives you an idea of how the representations and processes discussed so far can aid in comprehension of complex cognitive activities.  For more, take the language class in the fall.

Cognitive Psychology Notes 12
Will Langston

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