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Class #12Theory of Mind

Language and MindHONR 218L

Schedule

• Today: Theory of Mind• Wed March 14th: Manner of Motion,

Prepositions

• SPRING BREAK

• Mon, March 28th: Presentations• Wed, March 30th: Presentations

Monday March 28Navigation

• LeannaLinda Hermer & Elizabeth Spelke. (1996). Modularity anddevelopment: The case of spatial reorientation. Cognition, 61,195-232.

• KellianLinda Hermer-Vasquez et al. (2001). Language, space, and thedevelopment of cognitive flexibility in humans: The case of twospatial memory tasks. Cognition, 79, 263-299.

• RobLinda Hermer-Vasquez et al. (1999). Sources of flexibility inhuman cognition: Dual-task studies of space and language.Cognitive Psychology, 39, 3-36.

Mon or Wed (Mar 28 or 30)Number and Language

• OliviaKaren Wynn. (1998). Psychological foundations of number: numericalcompetence in human infants. Trends in Cognitive Sciences, 2, 296-303.

• JasonFei Xu. (2003). Numerosity discrimination in infants: Evidence for twosystems of representation. Cognition, 89, B15-B25.

• AlisonGregory Sulkowski & Marc Hauser. (2001). Can rhesus monkeysspontaneously subtract? Cognition, 79, 239-262.

• ChazPeter Gordon. (2004). Numerical cognition without words: Evidence fromAmazonia. Science, 306, 496-499.

• ChristinaPierre Pica et al. (2004). Exact and approximate arithmetic in an Amazonianindegene group. Science, 306, 499-503.

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Wed March 30Theory of Mind

• AlisaJosep Call & Michael Tomasello. (1999). A non-verbal falsebelief task: The performance of children and great apes. ChildDevelopment, 70, 381-395.

• LisaCourtney Hale & Helen Tager-Flusberg. (2003). The influenceof language on theory of mind: A training study. DevelopmentalScience, 6, 346-359.

• Matt• Jill de Villiers & Peter de Villiers. (2003). Language for thought:

Coming to understand false beliefs. In: D. Gentner & S. Goldin-Meadow (eds.), Language in Mind. MIT Press. [Deaf children,pp. 352-362.]

Presentations• Time: 15 minutes• Aim: Explain key ideas and/or evidence to class

• Visual aids– Serve as back-up to presenter– Serve as class notes– No bells and whistles

• Feedback– Talk to us!– Send a draft!

Whorf (1939)The Relation of Habitual

Thought & Behavior to Language

Whorf (1939)The Relation of Habitual

Thought & Behavior to Language

Whorf’s questions in his own words :

1) Are our own concepts of time, space, and mattergiven in substantially the same form by experienceto all men, or are they in part conditioned by thestructure of particular languages?

2) Are there traceable affinities between a) culturaland behavioral norms and b) large-scale linguisticpatterns?

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Critics

Stephen Pinker Geoffrey Pullum Theory of Mind

• Sarah thought that the earth was flat

• The embedded proposition encodes the contents ofSarah’s mind.

• The ‘truth value’ of the embedded proposition cannotbe evaluated with respect to this world. It must beevaluated with respect to Sarah’s mental world.

• What if a child didn’t know this?

If you can correctly evaluate thetruth of sentences like these, what

do you know?

• Syntactic Knowledge: you know that some verbs can takesentential complements

• Social Cognitive Knowledge: you know that other people canhave a false belief

• Bridge: you know that there is a connection between thissyntactic form and the expression of potentially false beliefs

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How is this knowledge acquired?

• Usual direction of effect between the developmentof concepts and the language that encodes them isthat the concept develops before thecorresponding terms

• Syntactic Knowledge: you know that some verbs can take sententialcomplements

• Social Cognitive Knowledge: you know that other people can have afalse belief

• Bridge: you know that there is a connection between this syntacticform and the expression of potentially false beliefs

Concepts before knowledge

• “The way we see colors determines how welearn words for them, not vice versa.” —Pinker

An alternative view

• The ability to represent and explain the beliefs,desires, intentions, etc. of others may rely on theability to represent the syntax of complementclauses.

Jill de Villiers, Smith College

• Syntactic Knowledge: you know that some verbs can take sententialcomplements

• Social Cognitive Knowledge: you know that other people can have afalse belief

• Bridge: you know that there is a connection between this syntacticform and the expression of potentially false beliefs

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Language as a ToolkitNeo-Whorfian Idea

• Language does not simply allow us tocommunicate complex and novel ideas

• Language allows us to represent complexand novel ideas, i.e., language as an enablerfor thought

Problem:

• How do you measure children’sunderstanding that other people canhave false beliefs

(abstracted away from their linguisticability to represent false beliefs)

False-belief Task• The child is introduced to two puppets, Sally and Anne. While playing,

Sally puts a marble into a basket and then goes outside (the puppetdisappears under the table, for example). When Sally is not around,naughty Anne changes the location of the marble. She takes it out ofthe basket and puts it in a box. Some time later Sally comes back andwants to play with her marble.

Children are then asked the critical question:Where will Sally look for her marble?

• 3-year olds typically fail4-5 year olds typically succeed

• Key problem in Autism

Dora the Explorer

Swiper the Fox

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Language Development

• At what age do children start talking aboutthoughts/beliefs?

• At what age do children first begin to use sententialcomplements?

Early Language Lacks MentalVerbs

• Two-year Olds

– Talk a lot!– … about what they did, what they want– … about what other do– … possibly about what others say– … not about what others think

Early Language Development:Understanding sentential complements

of communication verbs

• “The Mom said she bought apples. But look! Shereally bought oranges.”

“What did the Mom say she bought?”

• 3-year olds: oranges4-year olds: apples

Appearance of Mental verbs

The appearance of mental verbs like think,know is early (3 years) but often stereotyped

e.g. “I don’t know” or “I think I can”.

There are sporadic real uses.

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The breakthroughAt around four years of age, children understand that

mental verbs can take a whole sentence in theirscope (a complement) e.gMom thought that the shampoo was the toothpaste

And the embedded sentence can be FALSE from thechild’s Point of View, but TRUE for Mom.

Once the child has this capacity, he can represent twoworlds: his own, and someone else’s mental world.

Problem

Use of mental verbs with sententialcomplements occurs at roughly the sametime that children are able to pass false belieftasks.

Chicken or egg?

A longitudinal study withtypically developing children

• deVilliers & Pyers, 2002

• Main research question: Does the emergence offalse-belief understanding depend on the child’smastery of the grammar (syntax and semantics) ofsentential complements?

• 28 children, age 3–5 tested 4 times each over thecourse of 1 year

• Test battery included a variety of language tests anda variety of false belief tasks

False-belief tasks:Unexpected Contents Task

• Child is given a familiar container (band-aid box, playdoh box)• Child opens container and finds something unexpected

• False belief question: Child is told that a classmate (Sarah)will be brought in, and is asked “What will Sarah think is in thebox?”

• Control question: Child is asked “Before, when you weresitting over there, what did you think was in the box?

• 3-year-olds typically answer incorrectly to BOTH questions

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False-belief tasks:Unseen Displacement (Sally-Anne)

• Story: This boy Bobby and his daddy bought a nice cake for afterdinner. But Bobby wanted to go out to play so he put the cake awayuntil after dinner. He put it in this cupboard for later. Then he went outto play. Then the daddy thought, “Oh no, the frosting on the cake mightmelt!” So he took the cake out of the cupboard and put it in therefrigerator so the frosting wouldn’t melt. Then he went out to get sometomatoes for dinner.

• Memory check questions: Where did Bobby put the cake? Where isit now?

• False-belief question (prediction): Now Bobby is tired of playing andhe’s coming home. He remembers where he put the cake. When hecomes in the kitchen, where will Bobby first look for the cake?

• Explanation question (justified prediction): Why will he look there?

False-belief tasks:Explanation of Action

• Setup: Child is shown a puppet which is then put to sleep out ofsight. While puppet is sleeping, the child is shown a familiar box(e.g. egg carton), and the contents are removed and hidden ina neutral box. Puppet is then brought back. Child is then toldthat the puppet likes to eat eggs when he wakes up. Thepuppet then picks up the egg carton and tries to get it open.

• False-belief Question1: Why is he looking in there?• False-belief Question2: Why isn’t he looking in the other box?

Language tasks:Memory for complements in

described mistakes• Method: Child views pictures of stories in which a character is

described as making a mistake, telling a lie, or having a false belief.Child has to report the content of the mistake. Both mental state andcommunication verbs used.

• Example1: He thought he found his ring (second picture), but it wasreally a bottle cap. What did he think? (pointing back to the firstpicture)

• Example2: She said she found a monster under her chair, but (secondpicture) it was really the neighbor’s dog. What did she say? (pointingback to first picture)

• Important: This task does not require the child to “read” the character’sstate of mind, but merely to represent it by holding the sentence inmind and then repeating the relevant part back.

Language tasks:Spontaneous Speech

• Collected while children talked during the test sessions, playedcomputer games with the experimenters, and after watching silentvideos

• Analyze for BROAD measures of language development– Mean length of utterance (MLU)– IPSYN: total score (test indicating the range and complexity of grammatical

forms used)– Just the score for sentence types (of any kind)– Just the score for complex sentences (of any kind)– Complex sentence score MINUS sentence complement score

• Analyze for TARGETED measures of language development– The total score for just sentence complements

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Language tasks:Medial Answers to wh-questions

• Story: This little girl went shopping one afternoon but she wasvery late going home. She went a short way home over a fensebut she ripped her dress on the wire. That night when she wasin bed she told her mom, “Look, I ripped my dress thisafternoon!”

• Question: When did the girl say what she ripped?

• Right answer: The answer to the short distance question (Whendid she say it?)

• Wrong answer:– The answer to the long distance question (When did she rip it?)– Medial answer: (What did she rip?)

Correlations of language measures withfalse-belief measures at Round 2

Correlations of language measures withfalse-belief measures at Round 2

Sentential complement language measures: 3/24 correlate

Correlations of language measures withfalse-belief measures at Round 2

General language measures: 3/24 correlate

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What does this tell us so far?

What do we still not know?

Recall

• Main research question: Does the emergence offalse-belief understanding depend on the child’smastery of the grammar (syntax and semantics) ofsentential complements?

• Still unanswered: What direction does the correlationgo?

Contingency Tables of passingMemory for Sentential Complements

(syntax) and False Belief (FB)

Fail Syntax Pass SyntaxFail FB 1 13Pass FB 5 10

Criteria for passing FB: 5/6 correctCriteria for passing syntax: 10/12 correct

Contingency Tables of passingMemory for Sentential Complements

(syntax) and False Belief (FB)

Fail Syntax Pass SyntaxFail FB 1 13Pass FB 5 10

Explaining exceptions: “In every case, children whopassed false beliefs gave us evidence that they hadproductive command of complementation.”

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Another test of direction of correlation

Using statistics (multiple regression), you can ask: whatpredicts what?

Statistical Question: Do language measures (general orspecific) at Round 2 predict false belief results at Round 3?

Answer:General language measures do notIPSYN sentential complements do notWh-questions do notMemory for sentential complements does

Important Comparison

The converse does not hold:

Statistical Question: Do false belief results at Round 2predict Memory for Sentential Complements at Round 3?

Answer: NO

Important Comparison

The converse does not hold:

Statistical Question: Do false belief results at Round 2predict IPSYN sentential complements (spontaneous use)at Round 3?

Answer: NO

An intriguing twist

• The crucial component of memory forcomplements that makes it a significant predictor offalse belief performance is

–the communication verbs–not the mental verbs

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How do children learn the connection betweensentential complements of verbs and the

expression of potentially false beliefs?

• Difficult to observe: someone else’s thoughts

• Easier to observe: what people say

• “She said that she washed her hands”

• Children will sometimes hear sentences like this in a context where thereis overt evidence to suggest that the embedded proposition is false.

• Children can use evidence from verbs like say to generalize to verbs likethink and believe

• Syntactic Knowledge: you know that some verbs can take sententialcomplements

• Bridge: you know from hearing communication verbs and fromobserving the world while hearing them that there is a connectionbetween this syntactic form and the expression of potentially falsepropositions

• Having learned this connection from communication verbs, you thengeneralize that since mental verbs also take sentential complements,their sentential complements must also potentially be false.

• Social Cognitive Result: Therefore you can contemplate other(mental) worlds.

Sarah thought that the earth was flat

Summary of Main EmpiricalFinding

• Mastery of sentential complement structures is thebest predictor of false-belief performance, and this isNOT just a function of higher overall language ability

Conclusions• Results do not prove, but are compatible with these

claims:

• “The child needs the full syntax of mental verbs plus sententialcomplements in order to represent in his own mind the beliefstates of other people, not simply to encode them for reporting themin speech”

• The language paves the way for reasoning about others’ mentalstates: False Belief understanding.

• Language in this domain seems to drive Theory of Mind ratherthen vice versa.

• Question :What predictions do these claims make?

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Theory of Mind Presentations

• Testing the Connection in other ways or with otherpopulations

– What if you train children on communication verbs that takesentential complements? Do they improve on false belieftask?

– Test development in deaf children who are languagedelayed vs. not

– Test false belief understanding in non-humans

Another avenue forinvestigation

• Verbs of communication like say, tell, may providethe bootstrap for figuring out complements withmental verbs

• What predictions would this make?

Back to Pinker:What do we think now?

• “There is no scientific evidence that languagesdramatically shape their speakers’ ways of thinking.”