Linguistic Illusions:

where you see them, where you don’t

Colin PhillipsDepartment of Linguistics

Neuroscience & Cognitive Science ProgramUniversity of Maryland

languagescience.umd.edu

if you can barely read these words,please move forward!

clinical

educationalengineering

& computation

neuroscience

philosophy

computer science

electrical engineering

information science

literacy

hearing/speech sciences

second language acquisition

neuropsychology psychology

cognitive neuroscience

anthropologycognitive science& linguistics

Language Science

Ambiguity

Today’s focusSuccesses & failures that we’re unaware of

The Cotswolds, England

Matt WagersEllen LauBrian DillonNina KazaninaMasaya YoshidaMing XiangClare Stroud

Sachiko AoshimaAkira OmakiPedro AlcocerWing Yee ChowJon SprouseAlexis WellwoodLeticia Pablos

Amy WeinbergJeff LidzRoumi PanchevaValentine HacquardMoti LiebermanShevaun LewisDave Kush

Robust in noisy environments

ジョンが John-gaJohn.nom

マリーに Mary-niMary.dat

りんごを ringo-oapple.acc

食べた tabetaate

犬を inu-odog.acc

あげた。 agetagave

‘John gave Mary the dog that ate the apple.’

ジョンが John-gaJohn.nom

マリーに Mary-niMary.dat

トムが Tom-gaTom.nom

お店で mise-destore-at

ミルクを miruku-omilk.acc

買ったと katta-tobought.decl

言った。 ittatold

‘John told Mary that Tom bought the milk at the store.’

Rapid Irrespective of Word Order

Japaneseverb

verbrelative clause

relative clause

‘the dog was big and scary’

At each word …

1. visual/acoustic processing 2. phoneme recognition3. word recognition4. syntactic analysis 5. semantic interpretation

Fast

3-5 words/second200-400 msec/word

Pylkkänen et al. 2002

Halgren et al. 2002

Electrical/magnetic brain activity

Word access: ~250-400 msec

260 ms 280 ms 310 ms 340 ms

Computational Bottleneck

Updating interpretation at each word requires much more time than is available.

Option 1

Option 2

Option 3

Linguistic Illusions

auditory [pa] + visual [ka] = perceptual [ta]McGurk 1976

“And in the absence of large-scale policy differences between the two candidates, the personal nature of their exchanges are more likely to result in lasting damage.” [4/9/08]

“Republicans privately acknowledge this, arguing that in the hands of a more popular politician, the ideas that Cheney are putting forward could find fertile ground with the American people.” [5/21/09]

Agreement

the personal nature of theirexchanges are

the ideas that Cheneyare putting forward

“More people have been to Russia than I have.”

Comparatives

Selective Fallibility

1. Success2. Failure

Obvious … not-so-obvious

• Many features of languages are obvious …

1. English verbs precede their objects (ate the pizza) Japanese verbs follow their objects (piza-o tabeta)

2. English distinguishes the vowels in sheep and ship Spanish does not

etc. etc. etc.

• Many are not remotely obvious – new discoveries daily

Non-obvious properties can be especially revealing about how human minds/brains make language possible.

Long Distance Relations

AgreementThe children that I saw at the park this morning were building a fire.

Pronouns (‘co-reference’)The children that I saw this morning knew that they were late for school.

Question formationWhat were the children that I saw in the park looking for ___?

Squid Giant Axon

Pronoun Interpretation• In some sentence-types, name-pronoun order is flexible

– While John was reading the book, he ate an apple.– While he was reading the book, John ate an apple.

• In minimally different sentences, it is not flexible

– John ate an apple while he was reading the book.– *He ate an apple while John was reading the book.

• Reflects a constraint on interpretation (‘Principle C’) that is:

i. Formally straightforward (‘antecedent can’t be in scope of pronoun’)ii. Cross-linguistically robust – a likely universal of human languageiii. Developmentally privileged – children know by age 2.5-3 yearsiv. Obscure, and has limited functional value

Can search for pronoun interpretation ignore inappropriate nouns?

While she was taking classes full-time, Jessica was working two jobs to pay the bills.While she was taking classes full-time, Russell was working two jobs to pay the bills.

While she …Jessica …

Russell …

Gender Mismatch Effect

(Kazanina et al., 2007)

Good co-reference

----- -- --- ------- --- ----- ---- --- -- ------

Self Paced Reading

While -- --- ------- --- ----- ---- --- -- ------

Self Paced Reading

----- he --- ------- --- ----- ---- --- -- ------

Self Paced Reading

----- -- was ------- --- ----- ---- --- -- ------

Self Paced Reading

----- -- --- reading --- ----- ---- --- -- ------

Self Paced Reading

----- -- --- ------- the ----- ---- --- -- ------

Self Paced Reading

----- -- --- ------- --- book, ---- --- -- ------

Self Paced Reading

----- -- --- ------- --- ----- John --- -- ------

Self Paced Reading

----- -- --- ------- --- ----- ---- ate -- ------

Self Paced Reading

----- -- --- ------- --- ----- ---- --- an ------

Self Paced Reading

----- -- --- ------- --- ----- ---- --- -- apple.

Self Paced Reading

While she was taking classes full-time, Jessica was working two jobs to pay the bills.While she was taking classes full-time, Russell was working two jobs to pay the bills.

While she …Jessica …

Russell …

Gender Mismatch Effect

(Kazanina et al., 2007)

Good Bad300

340

380

420

460

500

MatchMismatch

Pronoun interpretation is ‘blind’ to grammatically inappropriate nouns.

(multiple constructions in English, also Russian, even Japanese)

Good co-reference

She was taking classes full-time while Jessica was working two jobs to pay the bills.She was taking classes full-time while Russell was working two jobs to pay the bills.

She …while Jessica …

while Russell …

Bad co-reference

Few people think that anybody realizes that Englishmen cook wonderful dinners

Question Formation

Question Formation

Few people think that anybody realizes that Englishmen cook what

What do few people think that anybody realizes that Englishmen cook

Question Formation

Question Formation

What do few people believe anybody who claims that Englishmen cook

relative clause

A relative clause is an ‘island’ – a wh-word cannot escape from it. (another cross-linguistically robust constraint)

Does the constraint impact real-time comprehension of questions?

Howmanystudentsdidtheschoolenlargetheclassroomfor?

How many students did the school enlarge the classroom for __?

Question Formation

What do few people believe anybody who claims that Englishmen cook

relative clause

A relative clause is an ‘island’ – a wh-word cannot escape from it.(another cross-linguistically robust constraint)

Does the constraint impact real-time comprehension of questions? Yes!

Even in Japanese, where relative clauses come at you from behind!

Stowe 1986; Traxler & Pickering 1996; Phillips 2006; Wagers & Phillips, 2009; Yoshida, Aoshima, & Phillips 2004

Infallibility• Moral so far for the comprehension “bottleneck”:

– Language comprehension is remarkably grammatically sensitive

– Little need to appeal to mechanisms that build ‘rough and ready’ interpretations to get the job done

Peripheral drift illusionAkiyoshi Kitaoka, Kyoto U

“And in the absence of large-scale policy differences between the two candidates, the personal nature of their exchanges are more likely to result in lasting damage.” [4/9/08]

“Republicans privately acknowledge this, arguing that in the hands of a more popular politician, the ideas that Cheney are putting forward could find fertile ground with the American people.” [5/21/09]

Agreement

the personal nature of theirexchanges are

the ideas that Cheneyare putting forward

“The key to the cells unsurprisingly were rusty …”

(Bock & Miller 1991; Pearlmutter et al. 1999; Deevy et al. 1998; Staub 2009; Wagers, Lau, & Phillips 2009; Eberhard et al. 2005)

Agreement Illusions

“The key to the cell unsurprisingly were rusty …”

It’s not simply ‘proximity concord’:

“The musicians who the reviewer praise so highly …”

“The musician who the reviewer praise so highly …”

And it is selective – plurals create illusions, singulars don’t

“The keys to the cell unsurprisingly was rusty …”

And it happens to the best of us …

Not only do we produce agreement errors – we generally fail to notice them

“The sheer weight of all these facts and figures make them hard for anyone to understand.” [10/13/81]

Ronald Reagan

To: colin@umd.eduFrom: mwagers@ucsc.eduDate: February 1, 2011, 3:38:53AMSubject: ugh

"The ill-formedness of center self-embeddings are consequently believed to stem from …”(me, 10 minutes ago)

Matt WagersUC Santa Cruz

Negative Polarity Items (NPIs)

ever

anything

anybodyanywhere

yetJohn has ever been to DC.John hasn’t ever been to DC.

Nobody can solve the problem yet.

Somebody can solve the problem yet.

lift a finger

in yearssay a word

a damn thing

the slightest bit

a red cent

Negative Polarity Items (NPIs)

NPIs are licensed by negation and negative-like contexts

Nobody expects Congress to ever change.Voters expect Congress to ever change.Few people expect Congress to ever change.Voters doubt that Congress will ever change.

But the negation can’t be just anywhere – must be structurally higher than NPI

*The people [rel. cl. who can’t stand it] expect Congress to ever change.

No bills [that the democratic senators supported] will ever become law.*The bills [that the democratic senators supported] will ever become law.*The bills [that no democratic senators supported] will ever become law.

NPI Illusions

(German: Drenhaus et al. 2005; English: Xiang, Dillon, & Phillips, 2009)

“More people have been to Russia than I have.”

Comparative Illusion

(Montalbetti 1984, Townsend & Bever 2001, Wellwood et al. 2009)

I’m not going to solely blame all of man’s activities on changes in climate

I’m not one to attribute every activity of man to climate change

9/30/08

10/02/08 Role Reversal Illusion

• Real-time processes are not grammatically ‘infallible’

• … but nor are they the product of a rough-and-ready analyzer

• Possible sources of “selective fallibility” profile:

– Hard-coded in parser – arbitrary?– Predictable based on properties of individual constraints?

(i) Time-course(ii) Memory search mechanisms(iii) Interpretive consequences(iv) etc.

Selective Fallibility

Explaining Selective Fallibility

1. Directionality2. Memory Access3. Semantic Extensions

Recipe for Success• Examples of very successful on-line constraint application

– Pronoun interpretation (Principle C) hei … Johni …– Wh-questions (‘islands’) whati … verbi …

– Plus various other cases of impressive speed or sensitivity

• All implicate predictive processes

– Analyzer can engage in prospective search for specific items– Forewarned is forearmed: parser can anticipate relevant details– Grammatically inappropriate domains can be excluded in advance

of perceptual content; may protect against interference

Recipe for Success• Examples of very successful on-line constraint application

– Pronoun interpretation (Principle C) hei … Johni …– Wh-questions (‘islands’) whati … verbi …

• Examples of grammatical illusions - retrospective

– Negative Polarity Items the bills [that no senators …] ever …

– Agreement the runners that the driver see …

Braver, Paxton, Lock, & Barch, PNAS, 2009

Dual Mechanisms of Cognitive Control (Braver et al. 2007)

Proactive Control: active maintenance of goal, more robust to interference (less available to older adults)

Reactive Control: more transient, more sensitive to interference

Recipe for Success• Examples of very successful on-line constraint application

– Pronoun interpretation (Principle C) hei … Johni …– Wh-questions (‘islands’) whati … verbi …

• Examples of grammatical illusions - retrospective

– Negative Polarity Items the bills [that no senators …] ever …

– Agreement the runners that the driver see …How does subject-verb agreement count as a ‘retrospective’ process?

Agreement Illusion

Agreement illusions are even more selective – grammatical asymmetry

Wagers, Lau, & Phillips, 2009

Illusions of grammaticality

*Stacey met the player who the coach like best… *Stacey met the players who the coach like best…

No Illusions of ungrammaticality

Stacey met the player who the coach likes best… Stacey met the players who the coach likes best…

speeded acceptability judgments

% a

ccep

tanc

e

the keysingular to the cellsplural verbsingularverbplural

Illusions reflect faulty memory retrieval (well, some of them)

Why is memory retrieval susceptible to interference?

Is all linguistic memory retrieval like this?

Is there a green square?

Is there a green square?

Is there a green square?

Is there a green square?

Is there a green square?

Is there a green square?

Is there a green square?

Is there a green square?

Is there a green square?

Is there a green square?

Is there a green square?

Dual Visual Search Mechanisms

Feature search is(i) fast, set-size invariant(ii) susceptible to interference, partial matches, and “illusory conjunction”

Conjunction search is slow, serial

(Treisman & Gelade 1980 etc.;but cf. McElree & Carrasco, 1999)

the key

to the cells were

S

Subj

PP

VP

V

the key

to the cells were

S

Subj

PP

VP

V

Two ways to search structures in memory

serial, structure-guided search parallel, cue-guided search

+plural+subject

10000001

structure-sensitive, avoids interference

slow, esp. for longer relations

susceptible to interference

fast, even for longer relations

McElree et al. 2003; Lewis et al. 2006; Wagers, Lau, & Phillips, 2011

Same Memory – Different Access

Subject-Verb Agreement

The diva [that accompanied the harpist on stage] clearly was flawless …The diva [that accompanied the harpists on stage] clearly was flawless …

The diva [that accompanied the harpist on stage] clearly were flawless …The diva [that accompanied the harpists on stage] clearly were flawless …

Subject-Reflexive Agreement

The diva [that accompanied the harpist on stage] clearly presented herself …The diva [that accompanied the harpists on stage] clearly presented herself …

The diva [that accompanied the harpist on stage] clearly presented themselves …The diva [that accompanied the harpists on stage] clearly presented themselves …

Dillon, Mishler, & Phillips, 2011

illusion

no illusionBoth processes require access to same element-- the subject of the same clause.

Testing reasons for different retrieval mechanisms

#1: Reflexives – interpreted as the ‘agent’ of the adjacent verb; avoiding direct retrieval

Test: Chinese long-distance reflexive ziji can co-refer with subject of higher clause, should block this strategy

Finding: Chinese ziji works just like himselfDillon et al. 2010

Alcocer et al. 2010

#2: Perhaps reflexive pronouns like ‘himself’ are richer memory cues than verbs like ‘were’

Test: Brazilian Portuguese verbs can be cues for agreement or for pronoun interpretation

Finding: same retrieval cues, but agreement vs. pronoun contrast persists

“More people have been to Russia than I have.”

Comparative Illusion

(Montalbetti 1984, Townsend & Bever 2001, Wellwood et al. 2011)

• Mis-remembering word order: ‘more’ is determiner & adverb

– People have been to Russia more than I have.– Test: change ‘more’ to ‘fewer’ (unambiguous)– Fewer people have been to Russia than I have. illusions persist

• ‘Additional more’

– ‘It’s not just me who has been to Russia’– Test: change second clause to block this interpretation– More girls have been to Russia than the boy has. illusions persist

• Word order clue

– More people have been to Russia [than I have] – More people [than I have] have been to Russia breaking 1st clause stops illusion

• Event comparison: consistent effects of ±repeatable predicates

Comparative Illusion: Possible Sources

(Wellwood, Pancheva, Hacquard, & Phillips, 2011)

More undergrads call their families during the week than grad students do.

More undergrads call their families during the week than I do.

More New Yorkers began law school this semester than I did.

3.78

5.286.05

More New Yorkers began law school this semester than rich Canadians did.

5.47

Rep

eata

ble

Non

-rep

eata

ble

Coherent Incoherent

(Wellwood, Pancheva, Hacquard, & Phillips, 2011)

• ‘Comparison of individuals’ treated as ‘comparison of events’

• This is quite common in normal language (Krifka 1990; Barker 1999)

– The [George Washington] bridge carried 107,912,000 vehicles in 2007.(Wikipedia)

– More vehicles crossed the bridge in 2007 than in any other year.

– More people have been to Russia in the past 10 years than in the previous 50.

Comparative Illusion

• Non-obvious phenomena reveal inner workings of language system

• Bottleneck for language understanding – so much to do, so little time!

Brain’s response: impressive multi-tasking, not a rush-job

• Selective FallibilityImpressive sensitivity … oftenTemporary blindness to errors … sometimes

• Cause for Misunderstanding?Little impact on real-life understanding

• BUT: success depends on highly effective time management.

Failure of these mechanisms couldunleash severe language problems

Linguistic Illusions

Thank you!