Transcript Garnsey presentation 03_02_06

A Strategy for Looking For Effects of
Discourse on Sentence Comprehension
• Look for effects of discourse context by making
sentence require something from discourse to make it
comprehensible
The businessmen loaned money at low interest …
Only businessmen loaned money at low interest …
… were told to record their expenses.
• Focus Operators like “only” require some contrast set
(Ni, Crain, & Shankweiler, 1996; Sedivy, 2002)
• Postnominal modification provides implicit contrast set
• Will that make Reduced Relative sentences easier to
understand?
Ni, Crain, & Shankweiler (1996)
• Stimuli
The businessmen loaned money at low interest were told to report …
Only businessmen loaned money at low interest were told to report …
• “Only”-version read faster at disambiguation “were told”
• Adding a prenominal adjective made it hard again
Only wealthy businessmen loaned money at low interest were told …
• When no discourse context (and no prosody),
- “only” wants some kind of noun modification that points
to a contrast set
• But, several others have failed to replicate these results
Sedivy (2002)
• Goals
– Replicate Ni et al.’s results
– Manipulate focus operator (only) and NP
definiteness separately (confounded in Ni et al.)
– Add discourse context manipulations
– Determine whether focus operator + discourse
manipulations affects processing of sentences that
end with the structure preferred by GP Model
• Frazier’s (1995) challenge
Experiment 1 - Stimuli
• Definite No Focus
The businessmen loaned money at low interest were told to report ..
• Definite Focus
Only the businessmen loaned money at low interest were told to report ..
• Indefinite No Focus
Businessmen loaned money at low interest were told to report ..
• Indefinite Focus
Only businessmen loaned money at low interest were told to report ..
• Unambiguous controls used morphologically
unambiguous verbs like “taken”
Experiment 1 – Procedure & Design
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Self-paced moving window reading
Comprehension Qs after ~1/3 of trials
24 experimental item sets (6/cond/subj)
16 unambiguous control item sets (4/cond/subj)
56 fillers w/ various other structures
• 48 participants
Experiment 1 – Results
Def
Foc
Indef
Foc
Def
No-Foc
Indef
No-Foc
… loaned money
737
733
671
710
at low interest
766
777
723
744
were told
628
588
673
656
Slower at “loaned money” when preceded by “only”
- Because “only” boosts Reduced Rel possibility, leading to
competition between RR and Main Verb possibilities?
- Or because doing work there to set up contrast set?
Faster at “were told” when preceded by “only”
- Confirms that there’s a Reduced Relative and thus postnominal
modification that supplies an implicit contrast set
Experiment 1 – Results cont’d
• NO significant differences among conditions in
Unambiguous sentences
- So, longer RT in Ambig condition not JUST due to work
required to set up contrast set
- However, similar but weaker similar pattern of means in
Unambiguous sentences suggests SOME of the effect in
Ambiguous Sentences may be due to that
• No effects of definiteness, so dropping that
manipulation in following studies
Experiment 2
• Added 1-sentence contexts that did or did
not provide a contrast set
• Contrast
All of the secretaries and accountants were made to take a …
• No-contrast
All of the secretaries in the company were made to take a …
• Both RR and Main Verb target sentences
Only the secretaries prepared for the exam passed and earned …
Only the secretaries prepared for the exam and earned …
All experimental items begin with “only”
Experiment 2 – Results
Main V
Contrast
Main V
No Contr
RR
Contrast
RR
No Contr
… for the exam
567
592
557
591
and earned
/passed
669
752
810
718
raises/ and earned
644
769
634
627
Slower at “for the exam” after No-Contrast context
- Because Contrast context provides contrast set for “only”
Slower at disambiguation when
- Context supplies contrast for “only”, so don’t need postnom mod,
but turns out to be RR
- Context doesn’t supply contrast for “only”, so do need postnom mod,
but turns out to be MV
Stay slower only when context doesn’t supply Contrast, “only” needs
contrast, but sentence has MV so no contrast set ever supplied