syntax 4 nov 16, 2015 – day 34 brain & language ling 4110-4890-5110-7960 nsci 4110-4891-6110...

SYNTAX 4NOV 16, 2015 – DAY 34

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.

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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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What does it mean to lead someone down the garden path?

• The Cambridge Dictionary of American Idioms says that the negative connotation of ‘leading someone down the garden path’ is “based on the idea that a path in a garden is very pleasant, so someone who is brought along it can be deceived without noticing it.”

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A different kind of problem

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1. The old man the boat.

2. The man whistling tunes pianos.

3. The cotton clothing is made of grows in Mississippi.

4. The complex houses married and single soldiers and their families.

5. The author wrote the novel was likely to be a best-seller.

6. The tomcat curled up on the cushion seemed friendly.

7. The horse raced past the barn fell.

SYNTAX 4Sentence comprehension and syntactic parsing

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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

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• How would you solve this arithmetic problem?• 1 + 1 + 1 = ?• (1 + 1) + 1 = ?• 2 + 1 = 3• So you need to store the second half of the problem as you calculate

the first half.

• The prototypical example is keeping a telephone number in mind as you dial it:• 862-3417

• This sort of storage is known as working memory, and has been variously characterized as:• a scratch pad,• a temporary work space,• a buffer.

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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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Short-term memory• There is also something called short-term memory, which

I can never understand how it is different from working memory.

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Fluid vs. crystallized intelligence • Fluid (Gf) and crystallized (Gc) intelligence are factors of

general (G) intelligence.• Fluid intelligence is the capacity to think logically, recognize

patterns, and solve problems in novel situations.• Crystallized intelligence is the ability to use skills, knowledge,

and experience. It improves somewhat with age, as experiences tend to expand one's knowledge.

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Back to syntax

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• Parsing a sentence also exercises working memory.• [S [NP a cat] [VP is [PP on [NP the couch]]]]

S

NPa cat

VP

Vis

PPon the couch

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One or two working memories?• There is some debate over whether the working memory needed

for parsing is part of a general purpose working memory or constitutes its own specialized store of working memory.

• Evidence for the latter• Some patients who share severe deficits of general purpose working memory

as assessed by attention span tests are still able to understand complex spoken sentences.

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

• HH: does this mean that language is more an aspect of crystalized intelligence than fluid intelligence?

• Evidence for the former• Individual differences in working memory are implicated in strategies for

understanding complex spoken sentences.

• Ingram says it’s a tie.• I am going to try to test this in the next experiment.

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Some relevant tasks• Sentence processing

• Self-paced reading: • A sentence is presented as a series of words on a computer monitor,

and the subject presses a key on the keyboard after each word.• The horse raced past the barn fell.

• Working memory• Attention span

• How many digits can the subject remember and recall in normal or reverse sequence?

• Verbal working memory ~ reading/listening span• The subject reads/hears a series of sentences presented as a block. • How many sentences can the subject recall the last word of?• This span correlates highly with verbal SAT scores.

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Syntax vs. pragmatics: Ferreira & CliftonModified from Ingram p. 271; see Figure 13.1

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

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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 & Carpentersee Figure 13.2

Low reading span

Latency at by

unreducedrelative clause

reducedrelative clause

inanimatesubject

~450 ms ~500 ms

animatesubject

~450 ms ~500 ms

High reading spanLatency at by

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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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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.

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NEXT TIMEMore syntax

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