1 s yntactic c omplexity of d ifferent b asque w ord o rders: e vidence from n euroimage (erp) kepa...

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SYNTACTIC COMPLEXITY OF

DIFFERENT BASQUE WORD

ORDERS: EVIDENCE FROM

NEUROIMAGE (ERP)

Kepa Erdozia (University of the Basque Country)Itziar Laka (University of the Basque Country)Anna Mestres (University of Barcelona)Antoni Rodriguez-Fornells (ICREA and UB)

ESF/MCYT/EUROCORES: BFF2002-10379-E

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BASQUE: Free Word Order

•Canonical Order: Subject-Object-Verb

(De Rijk, 1969, Ortiz de Urbina 1986, Elordieta 2001…)

•Derived Orders: Object-Subject-Verb

Subject-Verb-Object

Object-Verb-Subject…

•Phrases can be arranged in almost any order

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vP

DP VP

DP V

gizon-ak emakume-a ikus-i du

man-the woman-the seen has Subject-Object-

Verb

SOV order

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vP

DP VP

DP V

gizon-ak emakume-a ikus-i du

man-the woman-the seen has Object-Subject-

Verb

XP

emakume-a woman-the

OVS order

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MORPHOLOGICAL AMBIGUITY

OBJECT PLURALPACIENT

SUBJECT SINGULAR

AGENT

EMAKUME-AK‘WOMAN-X’

Emakume-ak gizon-ak ikusi ditu woman-? man-? see has

‘The woman has seen the men’ or ‘The man has seen the women’

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•SOV is processed faster•SOV is processed easier•Ambiguous Chains are processed like canonical word order (Kaan, 1997)

•LAN & P600: Syntactic Complexity in derived order (Matzke et al, 2001; Felser et al, 2003)•N400: Semantic desambiguation (Hagoort et al., 2004)

SOV and OSV ProcessingExperiments I & II:Self Paced Reading & comprehension task:

Experiment III: Event Related Potentials (ERP):

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Experiment I: self-pace reading SOV vs OSV

Goal: to determine whether OSV sentences have a higher processing cost than SOV sentences:

(a) longer reading times

(b) comprehension problems

Participants: 23 native speakers

Materials: 2 conditions, 32 sentences per condition

2 lists :16 SOV sentences/16 OSV sentences

32 fillers (the same for two lists)

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Experiment I: Materials

emakume-ak gizon-a ikus-i du

woman-the/Subj. man-the/Obj. seen has

‘the woman has seen the man’

gizon-a emakume-ak ikus-i du

man-the/Obj. woman-the/Subj. seen has

‘the woman has seen the man’

Subject

Object

Verb Aux

Subject

Object

Verb Aux

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Mean Reading times of sentences: global score

•SOV order is processed faster than OSV order

Experiment I: Results

Reading time of two word orders

3500

3600

3700

3800

3900

4000

4100

4200

SOV OSV

Sentence Type

Tim

e (m

s)

p<0.005

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•OSV order elicited more errors than SOV order

Errors in the comprehension task

Experiment I: Results

Comprehension Task: Errors

0%2%4%6%

8%10%12%14%16%

SOV OSV

Sentence Type

Per

cen

tag

e

p<0.001

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Mean reading times Word by Word

•Unmarked form processed faster than marked

Experiment I: Results

•OSV requires a reanalysis of syntactic structure at subject position

Reading Times Word by Word

600

700

800

900

1000

1100

1200

1300

DP DP Vb Aux

Sentence Element

Tim

e (m

s)

sov

osv

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Experiment I: SOV vs OSV

• Marked constituents are harder to processed

• Canonical SOV sentences require less processing time

• Derived OSV sentences require syntactic reanalysis

• Displaced constituents increase syntactic complexity

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Experiment II: Processing of ambiguous chains

Goal: to determine whether there is any preference when processing ambiguous chains (SOV/OSV).

Participants: 23 native speakers

Materials: 3 conditions, 48 sentences per condition

3 lists: 16 SOV sentences

16 OSV sentences

16 AMBIGUOUS

48 fillers

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MORPHOLOGICAL AMBIGUITY

OBJECT PLURALPACIENT

SUBJECT SINGULAR

AGENT

EMAKUME-AK‘WOMAN-X’

Emakume-ak gizon-ak ikusi ditu woman-? man-? see has

‘The woman has seen the men’ o ‘The man has seen the women’

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Experiment II: Materials

Emakume-ek gizon-ak ikus-i dituzte

women the Subj. men the Obj. seen have

‘the women have seen the men’

Emakume-ak gizon-ak ikus-i ditu woman-? man-? seen has‘the woman has seen the men’ or ‘the man has seen the women’

Gizon-ak emakume-ek ikus-i dituzte

man-? women-the Subj. seen have

‘the women have seen the men’

Subject

Object

Verb+aux

Subject

Object

Verb+aux

Ambiguous Chain

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Results: Mean Reading time of the sentences

•Ambiguous chain is processed as SOV sentence

40004200

440046004800

50005200

54005600

Tim

e (

ms

)

SOV AMB OSV

Sentece Type

Reading time of sentences

n.s.p<0.001

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Results: SOV vs OSV, word by word

•Comparing SOV and OSV orders: replication of the first experiment, syntactic reanalysis

SOV vs OSV. Reading time word by word

700

900

1100

1300

1500

1700

1900

DP1 DP2 Verb Aux

Constituent of the sentence

Tim

e (m

s)

SOV

OSV

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Results: SOV vs Ambiguous Chain, Word by Word

SOV vs Ambiguous. Reading time, word by word

700

900

1100

1300

1500

1700

1900

DP1 DP2 Verb Aux

Sentence constituent

Tim

e (m

s)

SOV

AMB

•No evidences of syntactic reanalysis•Ambiguous chains are processed as SOV order sentences•SOV is the simplest processing solution.

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EXPERIMENT III: Electrophysiological evidences using event-related brain potentials (ERPs)

This experiment suggests that:

Participants: 24 right-handed native speakers

a) SOV is the canonical, underived word order in Basque, and it constitutes the simplest choice for sentence parsing

Materials:

4 conditions, 240 sentences per condition

2 conditions, unambiguous

2 conditions, temporally ambiguous

b) OSV word order is syntactically derived and therefore more complex to parse

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Experiment III: Materials

Subject

Verb+aux

Object

Subject Verb+aux

Object

‘the wolf has eaten the sheep’

otso-ak

wolf-the/Subj

Ardi-a

Sheep-the/Obj

jan

eaten

du

has

‘the wolfs have eaten the sheep(pl)’

Otso-ek

Wolfs/the/Subj

ardi-ak

sheep-the/Obj

jan

eaten

dituzte

have

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Experiment III: Materials

SOV temporally ambiguous

OSV temporally ambiguous

‘the wolf has eaten the sheep(pl)’

Otso-ak

wolf ?

ardi-ak

sheep ?

‘the wolf has eaten the sheep(pl)’

otso-ak

wolf ?

Ardi-ak

sheep ?

jan

eaten

ditu

has

jan

eaten

ditu

has

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Experiment III: ERP Results

Constituents of unambiguous SOV/OSV sentences:

Left Anterior Negativity was obtained for displaced subjects and objects

Syntactically displaced constituents increase the processing costs. (Kluender y Kutas, 1997)

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ERP RESULTS: SOV vs OSV

SOV OSV Left Anterior Negativity

LAN

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SOV OSV

ERP RESULTS: SOV vs OSV

Left Anterior Negativity

LAN

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Experiment III: ERP Results

Verb of unambiguous SOV/OSV sentences:

Syntactic integration of displaced constituent at verb position increases processing cost (Felser et al, 2003)

At verb position of OSV non-canonical sentences we obtained a syntax related P600 component.

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SOV OSV

ERP RESULTS: SOV vs OSV

P600/SPS

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Experiment III: ERP Results

Unambiguous SOV/OSV sentences:These components, LAN and P600 showed that non-canonical OSV sentences are syntactically more complex than canonical SOV sentences in the grammar of Basque

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Experiment III: ERP Results

Temporally ambiguous SOV/OSV:

The semantic disambiguation at the verb of OSV elicited a N400 component, related to semantic analysis and complexity

We didn´t find any difference between the two first constituents.

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SOV OSV

ERP RESULTS: DISAMBIGUATION

N400

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Basque’s underived word order is SOV

Conclusions

Displaced elements increase syntactic complexity

Non-canonical OSV order is syntactically more complex

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SummaryWe have provided processing and ERP evidence that gives support to the claim that Basque grammar is built upon a basic, head final sentence structure (SOV word order), despite the fact that this language allows almost all constituent combinations in a sentence. Building upon results from other languages, where it has been shown that underived word orders yield shorter reading times and less comprehension difficulties, we have shown that these results also replicate in Basque, although the specific word order signaled as less complex and easier to understand is systematically SOV.

ERP results also showed that OSV generated LAN and P600, both signaling syntactic complexity

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Thank you!

Contact e-mail: kepa9815@euskalnet.net

http://www.ehu.es/HEB/english_erdozia.htm