SYNTAX 5 NOV 18, 2015 – DAY 35 Brain & Language LING 4110-4890-5110-7960 NSCI 4110-4891-6110 Fall 2015.

SYNTAX 5NOV 18, 2015 – DAY 35

Brain & Language

LING 4110-4890-5110-7960

NSCI 4110-4891-6110

Fall 2015

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Course organization• Schedule:

• http://www.tulane.edu/~howard/BrLg/t1-Intro.html#schedule-of-topics

• Today's chapter:• http://www.tulane.edu/~howard/BrLg/t19-aIFG.html

• Fun with https://www.facebook.com/BrLg15/• Quiz before Thanksgiving will be in class & on

Blackboard.

11/18/15 Brain & Language - Harry Howard - Tulane University

http://www.tulane.edu/~howard/BrLg/t1-Intro.html%23schedule-of-topics

http://www.tulane.edu/~howard/BrLg/t1-Intro.html%23schedule-of-topics

http://www.tulane.edu/~howard/BrLg/t19-aIFG.html

https://www.facebook.com/BrLg15/

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GradesQ1 Q2 Q3 Q4 Q5 Q6 Q7

MIN 6 5 5 4 7 3 4

AVG 9.0 8.8 8.8 8.4 9.2 7.5 8.7

MAX 10 10 10 10 10 10 10


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COMBINATORIAL NET 2


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The lexical interface


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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?On-line processing

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Two types of processing

on-line

• Happens in real time.• Instructions for an

experiment to test it:• You will read a sentence,

one word at a time. • Push a key after each word.

off-line

• Happens after the fact.• Instructions for an

experiment to test it:• You will read a sentence.• Point to the picture that

describes it best.


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Working memory & syntax


• Left-to-right solution of arithmetic• 1 + 1 + 1 = ?• (1 + 1) + 1 = ?• 2 + 1 = 3

• Left-to-right parsing of a sentence.• [S [NP a cat] [VP is [PP on [NP the couch]]]]

S

NPa cat

VP

Vis

PPon the couch

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Working memory span or capacity• The amount of material that you can keep on your ‘scratch

pad’ is known as your working memory span or capacity.• How much is it?• Miller’s number: 7 ± 2

• It varies a little from person to person and even from domain to domain in the same person.• That’s the meaning of the “± 2”• Working memory span can be impaired in brain injury.• It has recently been shown to be correlated with fluid intelligence.


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The working memory needed for parsing …

… is part of a general purpose working memory

• Individual differences in working memory are implicated in strategies for understanding complex spoken sentences.

… constitutes its own specialized store of working memory.

• Some patients who share severe deficits of general purpose working memory are still able to understand complex spoken sentences.

• Individual differences in working memory are usually not implicated in on-line language understanding.


SYNTAX 4Sentence comprehension and syntactic parsing

11/18/15 Brain & Language - Harry Howard - Tulane University 11

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Syntax vs. pragmatics: Ferreira & CliftonSelf-paced reading (on-line) task

SentenceRelative clause

Subject Latency at by

1. The evidence examined by the lawyer shocked the jury.

reduced inanimate same as 3

2. The evidence that was examined by the lawyer shocked the jury.

unreduced inanimate quicker than 1

3. The defendant examined by the lawyer shocked the jury.

reduced animate same as 1

4. The defendant that was examined by the lawyer shocked the jury.

unreduced animate quicker than 3


The fact that there is no garden path at by in (3) shows that syntax can perform the parse without access to pragmatics.

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Just & CarpenterLow reading span

Latency at by

unreducedrelative clause

reducedrelative clause

inanimatesubject

~450 ms ~500 ms

animatesubject

~450 ms ~500 ms

High reading spanLatency at by


unreducedrelative clause

reducedrelative clause

inanimatesubject

~350 ms ~400 ms

animatesubject

~425 ms ~475 ms

Same as before: no competition from pragmatics to confuse (and

slow down) syntactic parse

Different: latency is indeed longer in bottom cell than top cell of reduced

relative clause > pragmatics creates a garden path

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Why?• ‘Cognitive capacity’

• Low span readers only have enough capacity to process syntactic cues; nothing is left over to process pragmatics > modular processing (syntax first).

• High span readers have enough capacity to process syntactic cues and pragmatics > interactive processing (all cues considered simultaneously).


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Syntactic complexity• How about these sentences?

• 8a) The dog chased the cat.• 8b) The cat hunted the rat.• 8c) The rat nibbled the cheese.• 9) The rat the cat hunted nibbled the cheese.• 10) The rat the cat the dog chased hunted nibbled the cheese.


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Center embedding


9) The rat the cat hunted nibbled the cheese.

The rat which the cat hunted nibbled the cheese.

10) The rat the cat the dog chased hunted nibbled the cheese.

The rat which the cat which the dog chased hunted nibbled the cheese.

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How might this be processed?


thematic role for ‘the rat’

thematic role for ‘the cat’

thematic role for ‘the dog’

The parser encounters …

the rat > look for a predicate to supply a thematic role …

the cat > wait, put the previous search on hold & look for another predicate to supply a thematic role …

the dog > wait, put the previous search on hold & look for yet another predicate to supply a thematic role …

Ok, now I am lost.

push-down stack

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Interim conclusion• The limit on center embedded is 2.• Given that Miller’s number is much larger, it would appear

that there is a working memory specialized for parsing.


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‘Edge’ embedding does not create this problem


i) The dog chased the cat that hunted the rat that nibbled the cheese.

ii) The dog that chased the cat that hunted the rat that nibbled the cheese was a dachshund.

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Thinking about sentences, and science

1. Mary bought a book for John.• The direct object THEME follows the verb in English.

2. Which book did Mary buy for John?• The direct object THEME follows the verb in English or precede its

clause when it is introduced by which.

3. John asked Mary about a student.• TOPIC is the object of the preposition about.

4. Which student did John ask Mary about?• TOPIC is the object of the preposition about, or it precedes its

clause when it is introduced by which.

• Is adding "it precedes its clause when it is introduced by which" a good idea?


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Generalization• You should have gotten the idea that every statement that

is made about NPs in English must be duplicated to take into account questions with which.• But clefting requires a tripling of statements about NPs:

• This book is what Mary bought for John.• Leprechauns is what John asked Mary about.

• And there are even more constructions that require even more duplication.

• Is this a good way to describe the grammar of English?• NO! because we lose track of perfectly good generalizations like

• the direct object follows the verb or • THEME is usually the direct object.

• Is there a principle of science that can help us out here?


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Leprechauns!

• Think of an explanation for something:1. The Earth spinning on its axis

makes day and night.

2. The Earth spinning on its axis or leprechauns pushing it, makes day and night.

3. Rain falls when water condenses in the atmosphere.

4. Rain falls when water condenses in the atmosphere or leprechauns piss from clouds.

• Does adding leprechauns to all our explanations make them better?


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Ockham’s razor, simplicity, economylex parsimoniae

• Ockham’s razor is a principle that generally recommends selecting from among competing hypotheses the one that makes the fewest new assumptions.

• Einstein-ish: “Make things as simple as possible, but not simpler.”


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Back to our sentences• The sentences and their leprechauns

a. Mary bought a book for John.

b. Which book did Mary buy for John?

c. John asked Mary about a student.

d. Which student did John ask Mary about?

• How to get rid of the leprechaunsa. Mary bought a book for John.

b. Which booki did Mary buy ____i for John?

c. John asked Mary about a student.

d. Which studenti did John ask Mary about ____i ?

• (b, d) are called filler-gap constructions, though the gap is also called a trace.


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Final project• Improve a Wikipedia article about any of the topics

mentioned in class or any other topic broadly related to neurolinguistics.

• Write a short essay explaining what you did and why you did it.

• Print the article before you improve it, highlighting any subtractions.

• Print the article after you improve it, highlighting your additions.


NEXT TIMEMore syntax

11/18/15 Brain & Language - Harry Howard - Tulane University 26

SYNTAX 5 NOV 18, 2015 – DAY 35 Brain & Language LING 4110-4890-5110-7960 NSCI 4110-4891-6110 Fall 2015.

Documents

online language

brain language slides

brain languageling

brain injury

couchworking memory

sentence comprehension

real time

fluid intelligence