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3/5/08 Psyc / Ling / Comm 525 Spring08

Back to Usual Issues• So, evidence supports both Parallelism &

Interaction of multiple within-sentence constraints

• And shows Verb Bias effects in sentences that should not require any reanalysis– But Verb Bias effects could be part of 1st stage, since

may be a kind of syntactic knowledge– And N+V plausibility effects are only testable in

sentences with Clause structure, so could be due to reanalysis

• What about constraints from outside sentence?


Discourse Context• What are Non-minimally Attached PPs?

– They modify the NP they follow– When does an NP need modification?– When it wouldn’t be clear in context who or what it refers to

• If you see/hear The doctor examined the patient with ...– In a context where there are several patients in the waiting

room– You may expect what follows to tell you which patient is

meant

– i.e., context may lead you to expect a Non-minimal Attachment


Altmann & Steedman(1988)

Contexts:A burglar broke into a bank carrying some dynamite. He planned to blow open a safe. Once inside, he saw that there was ...

• 2-safe context:... a safe with a new lock and a safe with an old lock.

• 1-safe context: ... a safe with a new lock and a strongbox with an old lock.

• Target Sentences:MA: The burglar blew open the safe with the dynamite and ...NMA: The burglar blew open the safe with the new lock and ...


• Prediction– If people use discourse context immediately,– they'll read new lock faster than dynamite after the 2-safe

context– because they need new lock to know which safe is meant

• Results (Moving-Window RT)– People did read new lock faster than dynamite after 2-safe

context– i.e., the Non-Minimally Attached sentence was easier than the

Minimally Attached sentence

• So, suggests people don’t always try the simpler structure 1st– What they try first seems to depend on the discourse context– BUT, these results have been notoriously difficult to replicate!

• What if the context comes from the world rather than the discourse?– If that influences parsing, the system is clearly very interactive


Tanenhaus, Spivey-Knowlton, Eberhard & Sedivy (Science, 1995)

• Head-mounted eyetracker• Track eyes while people look at visual

scenes & hear spoken instructions– They usually look at objects before reaching for

them• So eye movements can show what they’re

thinking of reaching for, based on how they’re understanding a sentence so far


Procedures• People looked at displays of 4 objects while hearing

instructions like:– Put the apple on the towel in the box.– Ambiguous between:

• Put the apple on the towel in the box. towel = destination (MA)

• Put the apple on the towel in the box. towel = modifier (NMA)

• The visual scene had either 1 or 2 apples present– If visual context influences parsing, then when there are 2

apples:• They should think PP modifies it, to pick out which apple• So they should not think the towel is a destination & thus

should not look at it (much)• - i.e., They should prefer the Non-Minimal Attachment


Typical Result in 1-Ref Condition

Only 1 applein display

Unambiguous version

Ambiguous version


Typical Result in 2-Ref Condition

Ambiguous version

Unambiguous version

2 applesin display


Overall Results


Interpretation• When there were 2 apples, people rarely looked

at the empty towel– Suggests rarely considered it as a possible destination

• Thus, that they did not always try MA first?– So, non-linguistic visual context immediately

constrained interpretation – So, sentence comprehension processing is

Interactive

• Whether you believe this interpretation– Depends on whether you think people would move

their eyes to the empty towel if they briefly mis-parsed the sentence & thought it was a destination ???


• The next section has slides from a talk of mine about a study with Reduced Relatives, showing some individual difference effects. I will talk about this study when we talk about memory and language processing, so don’t worry if you can’t figure it out from just the slides.


Individual Differences in the Effect of Yet-to-be-Fixated

Words during Sentence Reading

With thanks to: Elizabeth Myers Neal Pearlmutter Kate Pirog Mike Tanenhaus John Trueswell Gary Wolverton


My Very Favorite Example of a Garden-Path Sentence

“A University student charged with threatening to kill the President via email was arrested Thursday, following issuance of a complaint and warrant, officials said.”

- Daily Illini, 2/27/94


“A University student charged with threatening to kill the President via emailemail XY


You may not have noticed that there wasanother opportunity for garden-pathing

inthis example

with threateningto kill the President … ”

“A University student chargedwho was

^

“Reduced Relative”


The Most Famous English Garden-Path Sentence

The horse raced past the barn fell.

What makes this one so much harder? 1. Horses are good racers

2. The word past is no help after raced

vs A University student charged with


Dual Purkinje Eyetracker

For the font size and distance we use, spatial resolution is ~1/4 character


First-passReadingTime

= Sum of all fixations in a region before leaving the region

- Used as a measure of “initial processing”


Example Stimulus Set for Allof the Studies that Follow

Animate = Good AgentThe witness (who was) examined by the lawyer turned out to be unreliable.

Inanimate = Bad Agent = Possible Passive PatientThe evidence (that was) examined by the lawyer turned out to be unreliable.

Scoring Regions:The evidence / (that was) / examined / by the lawyer / turned out /…

Disambiguating Region


We thought there were some problems with the materials:

e.g.,The trash smelled by the dog was laying on the sidewalk.

The questions asked about the murder could not be answered.

The stories told about the incident were a great source of concern.


Daneman & Carpenter’s (1980)Reading Span Test

At the conclusion of the musicians' performance, the enthusiastic crowd applauded.

Without any hesitation, he plunged into the difficult mathematics assignment blindly.

The devastating effects of the flood were not fully realized until months later.

When I got to the big tobacco field I saw that it had not suffered much.


What does the test measure? - Verbal working memory capacity? - Ability to focus attention? - Skill with language and reading? - . . . ?

For some purposes, it doesn’t matter

- As long as it reliably identifies subgroups of people - Who can then be tested for differences in other tasks - Which may help us figure out what the test measures


Parafoveal Preview in Reading

Burgess (1991) - Self-paced moving window reading time study - Varied window size from single to several words

- Found an animacy effect only when people saw the disambiguating preposition “by” chunked together with the verb preceding itexamined by the lawyer turned out …e.g., The evidence

Ferreira & Clifton used a 40-character wide display - Sometimes the preposition was on the next line


We created sentences with verbs at least 8 characters long - So we could analyze data contingent on whether or not people were likely to get preview of “by” while still fixating on verb

The professor confronted by the student was not ready to …

If last fixbefore “by”was here,trial coded as “Preview Unlikely”

If last fix before“by” was here, trial coded as“Preview Likely”

If last fix before“by” was here,trial not used


48 item sets with 4 versions each:The professor (who was) confronted by the student was not ready for an argument.

The professor (had) confronted the student but was not ready for an argument.

All animate– Want people biased toward main clause interpretations- So sentences are fairly hard, so there’s a better chance to see how much preview of “by” can help


Participants - 23 high-span (>=3.5, 13 female) - 20 low-span (<=3.0, 10 female)

(More would be good, since breaking it down by both span & critical fixation locations & dropping some trials)


- People are differently abled when it comes to making rapid use of cues that can help in understanding hard sentences

- In Trueswell et al. (1994), - We probably just happened to get a high proportion of high-span subjects - And something about the display &/or materials happened to make it easy to get preview of “by”

- Presenting sentences one word at a time in ERP studies (among others) may yield unrepresentative results especially for highly skilled readers

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