dc.ppt

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dc.ppt

• version 20110418

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Deictic Centers the Cognitive Structureof
Narrative Comprehension

• Gail A. Bruder, Judith F. Duchan, David M. Mark,
  William J. Rapaport, Erwin M. Segal,Stuart C.
  Shapiro, Leonard Talmy, David A. Zubin, et al.
• Center for Cognitive Science
• rapaport_at_buffalo.edu
• http//www.cse.buffalo.edu/rapaport/dc.html

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Interdisciplinary Cognitive-ScienceResearch
Project(1982 - 1995)

• AI
• cognitive psychology
• education
• geography
• communicative disorders
• linguistics
• literary theory practice
• philosophy

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Deictic Center

• mental model
• of spatial, temporal, character info
• contributed by reader
• in order to understand narrative
• by tracking
• WHERE events occur
• WHEN events occur
• to WHOM events occur
• from WHOSE perspective
• DC ltWHERE, WHEN, WHOgt

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Understanding a Narrative

• Bottom-up approach Local Textual Cohesion
• John was ill, but he sang anyway.
• can be understood in 2 ways
• Syntactic (closed-text, interpretive) view -(
• links between text elements
• he linked to John
• 2 clauses linked by but

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Understanding a Narrative (contd)

• Semantic (open-text, constructive) view -)
• Reader constructsmental-model meaning (
  theory)from narrative text ( data)
• cf. Kamps Discourse Representation Theory
• John picks out item in (Rs MM of) story-world
• he picks out same one
• he/John link inferred
• but links 2 conceptual representations
• Problem Cant see the forest for the trees.

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Understanding a Narrative (contd)

• Top-down approach Global Textual Coherence
• Text-structure theories
• Rumelharts story grammars
• Schanks scripts
• Logical coherence of story world
• Problem Looks only at the forest, not at the
  trees

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Role of the Deictic Center

• story world coherence theories
• articulated by text-structure theories (too
  general)
• text cohesion theories (too specific)

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Role of the Deictic Center (contd)

• Goals
• To determine how DC can be computed by reader
  from
• cohesive devices
• world knowledge
• inference
• how reader can use DC to construct coherence

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Linguistic Clues for Tracking DC(David Zubin)

• Deictic operations(mental operations of the
  reader on the DC)
• introducing
• shifting
• maintaining
• voiding ( shift to null)
• actors (WHO)
• places (WHERE)
• times (WHEN)

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Linguistic Clues for Tracking DC (contd)

• Sample deictic operations on WHERE
• Hemingway
• The door to the café opened, and two men
• came in. WHERE inside
• went in. WHERE outside
• entered. WHERE indeterminate

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Linguistic Clues for Tracking DC (contd)

• Sample deictic operations on WHERE
• Introducing/shifting (preposed adverbials)
• Kino awakened in the near dark. The stars still
  shone and the day had drawn only a pale wash of
  light.The roosters had been crowing, and the
  pigs wereturningtwigs and bits of wood to see
  whether anything to eat had been overlooked.
  Outside the brush house in the tuna clump,birds
  chittered and flurried with their wings.
• Steinbeck, The Pearl
• Maintaining WHERE ( shifting WHO)(deictic verbs
  come, go, bring, take)
• Kino squatted by the fireand ate. When Kino
  had finished, Juana came back to the fire and
  ate.
• WHO Kino, WHERE location of WHOJuana enters
  the WHERE(come maintains the WHERE)

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Psychological Support(Gail Bruder, Erwin M.
Segal)

• come maintains DCs WHEREgo shifts it
• takes more time to respond to question about
  previous DC

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Psychological Support (contd)

• John and Mary were eating dinner when there was a
  knock at the door.
• (g) John got up and went to answer the door.(c)
  John looked up to see his partner come in.
• Kevin greeted John with a bottle of champagne and
  a big hug.
• They had just won a large advertising account.
• Is Mary in the dining room?

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Psychological Support (contd)

• Juana was preparing a fire. She broke little
  pieces of brush. Kino got up and wrapped his
  blanket around him. He came / went outside to
  watch the dawn. Kino squatted down.
• Is Juana inside the brush house?
• Initial WHERE location of WHO
  indeterminateKinos destination outside
• came
• if female reader then WHO Juana so
  WHERE outside so Kino moved to WHERE
• went
• if female reader then WHO Juana so
  WHERE inside so Kino moved from WHERE

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Communicative Disorders(Judith Felson Duchan)

• Goal
• To facilitate comprehension production of
  fiction in language- learning-disabled
  children
• Unique property of fiction
• How characters think feel is transparent to
  reader (D. Cohn)
• Children can manipulate mental states in fiction
• 4 yrs can understand subjective fictional
  experience
• 6 yrs refer to internal response of characters
  to events in story
• Can children produce narratives using
  subjectivity markers?

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Communicative Disorders (contd)

• Results
• Subject 5-yr-old, pre-literate girl
• 44 stories generated by subject from picture
  books
• psycho-narration 48 of stories
• descriptions of thoughts of character
• she felt terrible
• internal monologues 16 of stories
• exact language of characters thoughts
• I feel terrible, she thought
• represented thought 11 of stories
• representation of characters subjective
  experiencein deictically shifted language
• She winced as she heard them crash to the
  platform. The lovely little mirror that she had
  brought for Ellen, and the gifts for the baby!

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Communicative Disorders (contd)

• Individual differences
• Comprehenders understand narrative from different
  perspectives
• DC of some narratives is not obvious
• childs narrative adult comprehender
• Once there was a little boy who lived in the
  forest with his mother and father and his pet
  water beetle.
• He waited in the rain for his water beetle to
  come inside.
• He said, Come inside, water beetle!
• No, Im supposed to like the rain.
• Thats why they call me the water beetle.
• Where are the boy, mother, father, beetle in (1)?
• Where are the boy, beetle in (2)? In (3)?

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Computational Implementation

• SNePS
• fully intensional,propositional,semantic-network
  knowledge-representation reasoning system
• rule-based inference
• generalized inheritance
• belief revision
• can understand and generate natural language

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Computational Implementation (contd)

• WHEN (Stuart C. Shapiro, Michael J. Almeida)
• Temporal structure of narratives
• WHERE (Shapiro, Albert H. Yuhan)
• Reference-frame problem in narrative
  understanding
• WHO
• Belief representation (William J. Rapaport)
• Recognizing subjective sentences (Janyce Wiebe)
• if pressed for time, can omit next 4 slides

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Computational Implementation (contd)

• Cassie name of our computational model of a
  reader
• Cognitive Agent of the SNePS Systeman
  Intelligent Entity -)
• SNePS nodes represent objects of Cassies
  thoughts
• intentional objects
• individuals, properties, relations, etc.
• propositions
• Cassies mind grows (changes)
• Cassie believes what we tell her,as if it were
  fictional narrative

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Computational Implementation (contd)

• IntenSional knowledge representation
• To model a mind,a KRR system must model only
  intensional entities
• I.e., entities that can be
• distinct, even if logically or numerically
  equivalent
• non-existent
• Argument from fine-grained representation
• intenTional entities (i.e., objects of thought)
  are intenSional
• can have 2 objects of thought, but only 1
  extensional object
• morning star evening star
• President of the US, Commander-in-Chief of the US
  armed forces
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• Argument from displacement
• can think and talk about non-existent objects
• fictional (Sherlock Holmes, Santa Claus)
• impossible (mermaids, round squares)

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Computational Implementation (contd)

• WHEN Temporal Structure of Narratives
  (Almeida) (Are we there
  now?)Linear narrativeJohn arrived at the
  house. The sun was setting. He rang the bell a
  minute later, Mary opened the door.
• Initially, NOW is some time before John arrives
  at the house.
• An instant later, NOW has moved to during the
  time that the sun is setting.
• A short time later, John rings the bell.
• An instant later, NOW has moved to a minute
  before Mary opens the door.
• An instant later, at the end of the narrative,
  NOW has moved to after Mary opens the door.

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Computational Implementation (contd)

• WHEN Non-linear narrativeJohn was walking
  to the office. He entered the office at 300 in
  the afternoon. The secretary was busy. She was
  typing a letter. John waited for ten minutes.
  He left the office. On Thursday, he returned in
  the morning. The secretary gave him a check. On
  the following Tuesday, John returned to the
  office. He had lost the check on the previous
  afternoon.

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Computational Implementation (contd)

• WHERE The Reference-Frame Problem
  (Yuhan)
• Mary, tom, and Bob went to a theater together
  in order to see Bobs uncles show. They walked
  to the front of the hall. Bob sat two rows in
  front of Mary. Tom sat just behind her. They
  had a few minutes before the show would start.
  Mary was turned around in her seat talking with
  Tom. Then she saw a person who looked like Bob
  walking down the aisle toward her with a tall
  girl on his left. Recognizing Mary, he stopped
  in front of her to say hello. Mary glanced back
  and saw that Bob was still there in his seat.
  The person standing in front of Mary was Jim, who
  was Bobs twin brother. She had met him once
  before. Jim and the tall girl found seats a
  little distance away to Mary's left. Then the
  lights in the hall dimmed. They saw Bobs uncle
  standing behind a lectern to the left of a
  microphone.

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Computational Implementation (contd)

• WHERE The Reference-Frame Problem (contd)
• Input
• Mary, Tom and Bob went to a theater together in
  order to see Bobs uncles show.
• Original narrative has no explicit statement that
  they went in to the theater
• must be inferred in order to interpret front
  correctly
• Output (after constructing SNePS mental model)
• I understand that a group of individuals namely,
  Bob, Tom and Mary went to a theater and that they
  moved to a place which has a spatial relation of
  ideal-point to a member of the class theater.
  Furthermore, I infer that, presumably, the group
  were located at a place in a theater at a time
  after the time of the going and before the time
  of the seeing. WHEN is the time of being in the
  theater. WHERE is the place in the theater. WHO
  is the group.
• if pressed for time, can omit next 4 slides

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Computational Implementation (contd)

• WHO Belief Reports
• Columbus believed that Castros island was
  India
• True? De re report.
• False? De dicto report.
• Mary believes that she (herself) is rich
• De dicto, de se report
• she quasi-indicator
• logophoric pronoun
• a 3rd-person indexical that refers to the
  believer in a 1st-person way

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Computational Implementation (contd) AI
Literary Theory (Mary Galbraith, SDSU)

• Subjectivity in narrative (Wiebe, U/Pitt)
• References in narrative must often be understood
  w.r.t. characters beliefs
• in subjective sentences
• portraying characters thoughts, perceptions
• not in objective sentences
• presenting story directly
• Subjective context def
• sequence of subjective sentencesportraying
  thoughts or perceptions of 1 character
• Problem
• how to recognize subjective sentences their
  character

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Computational Implementation (contd) AI
Literary Theory

• (a) She winced as she heard them crash to the
  platform. (b) The lovely little mirror that she
  had brought for Ellen, and the gifts for
  the baby!
• describes emotional reaction
• 1st mention of mirror, Ellen, gifts, baby
• (a) Suddenly Zoe gasped. (b) She had touched
  somebody!
• exclamation /? represented thoughtsomebody
  Zoes reference
• (a) But what Muhammed had seen in those few
  moments made him catch his breath in amazement.
  (b) On the floor of the cave,there were several
  large cylindrical objects standing in a row.
• push to Ms belief space at seen or amazement
• superordinate description shows what M
  believes(that he doesnt know what the objects
  are,which isnt stated elsewhere)

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DC Projectas Interdisciplinary Cognitive Science
AI PHI
PSY
LIN
Understanding Narrative Understanding
CDS
ENG
GEO
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DC Projectas Interdisciplinary Cognitive Science
AI PHI
PSY
LIN
Understanding Narrative Understanding
CDS
ENG
GEO
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References

• Duchan, Bruder, Hewitt (eds.) (1995), Deixis
  in Narrative A Cognitive Science Perspective
  (Hillsdale, NJ Erlbaum).
• http//www.cse.buffalo.edu/rapaport/dc.html