SYNTAX 2DAY 31 – NOV 08, 2013

Brain & LanguageLING 4110-4890-5110-7960NSCI 4110-4891-6110Harry HowardTulane University

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Course organization• The syllabus, these slides and my recordings are

available at http://www.tulane.edu/~howard/LING4110/.• If you want to learn more about EEG and neurolinguistics,

you are welcome to participate in my lab. This is also a good way to get started on an honor's thesis.

• The grades are posted to Blackboard.

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REVIEW

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Linguistic model, Fig. 2.1 p. 37

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Discourse model

SyntaxSentence prosody

MorphologyWord prosody

Segmental phonologyperception

Acoustic phonetics Feature extraction

Segmental phonologyproduction

Articulatory phonetics Speech motor control

INPUT

SEMANTICS

Sentence level

Word level

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Example of syntactic structure• A fragment of English grammar

① S → NP VP② VP → V NP③ NP → Det N, where Det is one of {a(n), the, some}④ VP → V PP⑤ PP → P NP, where P is one of {on, in, at, by, etc.}

• [S [NP a cat] [VP is [PP on [NP the couch]]]]

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S

NPa cat

VP

Vis

PPon the couch

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SENTENCE COMPREHENSION AND SYNTACTIC PARSINGIngram IV. Sentence comprehension, §12

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The problem of assigning syntactic structure in real time• So, how did you do that?• You assigned a syntactic (or structural) description to the

sentence, following the rules of the grammar, presumably from left to right, which is a process known as performing a derivation.

• It is also known as parsing the sentence:• "to state the parts of speech in a sentence”, 1550s, • verb use of M.E. pars (n.) "part of speech" (c.1300), • from O.Fr. pars, pl. of part "part”,• from L. pars (see part (n.)) in school question, Quae pars orationis?

"What part of speech?"

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Start with the first wordIngram p. 246, Fig. 12.1

• A – what do we know about it?• Determiner, indefinite, singular• Ingram calls this Lexical Access and Feature Retrieval (LAFR)• What does our grammar tell us about a determiner (Det)?

• It is followed by a noun, so let’s look for one to the right.• And by the way, it should be singular, to agree with the determiner.

• Cat – what do we know about it?• Noun, singular (LAFR)• We also know a lot about the meaning of ‘cat’, but this theory of syntax assumes

that meaning is not relevant to the parse.• What does our grammar tell us about Det+N?

• That they form an NP, so let’s merge them into one:• [NP [Det a] [N cat]]

• What does our grammar tell us about NP?• It is followed by a (tensed) verb, so let’s seek one to the right.

• Do the rest of the derivation yourself. Skip the one on p. 247.

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Models of sentence processing• Traditional generative model

• A separate mental module parses sentences just like we just did. • Lexical access happens first.• Then one syntactic hypothesis is considered at a time.• There is no influence of meaning.

• More recent interactive model• There is no separate module for parsing• Lexical access, syntactic structure assignment, and meaning

assignment happen at the same time (in parallel).• Several syntactic hypotheses can be considered at a time.

• How to decide?• Agrammatism

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But first, a review: Thematic roles• What is a thematic role?• List of roles

• AGENT• EXPERIENCER• THEME• GOAL• SOURCE• LOCATION• RECIPIENT• INSTRUMENT

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Review: Thematic rolesa. John gave a tomato

to Mary.b. John gave Mary a

tomato.c. A brilliant idea

occurred to Mary.d. Mary hates

tomatoes.

a. AGENT gave THEME to RECEIPIENT

b. AGENT gave RECEIPIENT THEME

c. THEME occurred to EXPERIENCER

d. EXPERIENCER hates THEME

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Syntax vs pragmatics• How about these? (p. 251)

1) The cop arrested the teenagers. 2) The teenagers arrested the cop.

• How can we tell the difference?• Syntactic info:

• Subject agrees with verb;• subject precedes verb;• subject tends to be AGENT.• Direct object follows verb;• direct object tends to be THEME.

• Pragmatic info:• Police are typical arresters; • teenagers are typical arrestees.

• Note that syntax overrides pragmatics in (2).

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Review: language areas of the brain

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The Broca-Wernicke-Lichtheim model (of the LH)

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The two main aphasiasIngram p. 49

Broca’s

• C: What brought you to the hospital?

• P: yes … ah … Monday … ah … Dad … Peter Hogan, and Dad … ah … hospital … and ah … Wednesday … Wednesday … nine o’clock and ah Thursday … ten o’clock … doctors two … two … an doctors and … ah … teeth … yah … and a doctor an girl … and gums, an I.

Wernicke’s

• C: What brings you to the hospital?

• Boy, I’m sweating, I’m awful nervous, you know, once in a while I get caught up, I can’t mention the tarripote, a month ago, quite a little, I’ve done a lot well, I impose a lot, while on the other hand, you know what I mean, I have to run around, look it over, trebbin and all that sort of stuff.

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Agrammatic aphasia (agrammatism)One aspect of Broca’s aphasia

• Agrammatic aphasiacs may overlook agreement, but they are still sensitive to word order.

• However, they often rely on pragmatics, so they may understand (2) to mean (1):1) The cop arrested the teenagers. 2) The teenagers arrested the cop.

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Active vs. passive sentences• Ask the patient to point to the picture in which • The dog bit the postman.• The dog was bitten by

the postman.

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Reversible sentences • Agrammatic aphasiacs find the following reversible active

sentences to be difficult to understand (75% accuracy):3) The dancer applauded the actor.4) The actor applauded the dancer.

• Reversible passive sentences are even harder (50% accuracy):5) The actor was applauded by the dancer.

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Conclusions• It may be that agrammatic aphasiacs rely on a rule of

thumb (heuristic) based on the canonical word order of English or other frequent coincidences:a) The NP which precedes the verb is assigned the thematic role of

AGENT.b) The NP which follows the preposition by is assigned the thematic

role of AGENT.• How they help

• (a) helps agrammatic aphasiacs understand reversible active sentences.

• (a) and (b) conflict in reversible passive sentences, so agrammatic aphasiacs do worse (they guess).

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Complex sentences: Clefting • Clefting (p. 253)

8) The monkey chased the frog.9) It was the monkey that chased the frog. –– cleft subject, cf (8)10) It was the frog that the monkey chased. –– cleft object, cf (8)

• Which one should be more difficult for agrammatic aphasiacs?• (9) 100% correct• (10) 33% correct

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NEXT TIMEQ9. Continue with §12 Sentence comprehension and syntactic parsing

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