Syntactic representation

1. Syntactic representation

2. Last week • Lexical access: • Split between syntactic information (lemma) and phonological (word-form) information • Two models: • Levelt et al (modular) • Dell (interactive)

3. This week • From words to sentences • Where does syntax fit into the model? • Functional processing (grammatical functions) • Positional processing (constituent structure) • The nature of syntactic representations: • Syntactic priming

4. Lexical processing Lexical concepts (semantic content)  Lemmas (syntactic content)  Wordforms/lexemes (morpho-phonological content)

5. From words to sentences • Lexical entries that are retrieved must be combined into a syntactic structure. • Usually hypothesised to involve two stages of processing (e.g., Garrett, 1980): • Functional processing • Positional processing

6. Where do they fit?

7. What is the functional level? • Earliest level associated with linguistic processing. • Input is a conceptual representation • Output is a syntactic representation • perhaps a tree structure • built drawing upon lemma information • Level where: • lemma selection occurs • these are associated with appropriate grammatical functions (e.g., subject, direct object). • give’<postman, letter, doctor> > GIVE, POSTMAN, LETTER, DOCTOR > POSTMANSUBJ; LETTERDOBJ; DOCTORIOBJ

8. What’s the evidence? • Mostly from speech errors: • Phrase/Word exchange errors: e.g. Most cities are true of that. Writing a mother to my letter. • same grammatical category: • hence grammatical information relevant. • BUT: could this be meaning-related? • usually non-adjacent (81%): • hence unordered. • usually within clause: • hence domain of processing is usually one clause.

9. Evidence from errors. • Exchanging phrases/words are marked for grammatical function in landing position: e.g., She gives them the money NOT: Her gives they the money (Int: They give her the money) • hence, not just misordering of words. • Verbs usually agree with actual subject rather than intended subject. e.g. She gives them the money. Most cities are true of that.

10. Unordered representation • Linear order not specified at F-level. • Not obvious for English: • grammatical roles and order largely the same: • SUBJECT = first NP in sentence • DIRECT OBJECT = second NP in sentence e.g., ISUBJ like BillDOBJ - BillDOBJ likes meSUBJ • but: ISUBJ can’t standBenDOBJ, but BillDOBJ ISUBJ like

11. Unordered representation (2) • In other (more inflected) languages, grammatical function and linear order more easily separable: • Junge = boy; Mann = man; Buch = book Der JungeSUBJ gab dem MannIOBJ das BuchDOBJ Dem MannIOBJ gab der JungeSUBJ das BuchDOBJ Das BuchDOBJ gab der JungeSUBJ dem MannIOBJ Das BuchDOBJ gab dem MannIOBJ der JungeSUBJ = The boy gave the man the book

12. The positional level • Second level associated with linguistic processing. • Level where: • lemmas and associated grammatical functions are converted into phrase structure. • I.e, individual words are structured into larger linguistic units. • Essentially, syntax as most people think of it

13. The positional level • GIVE(POSTMANSUBJ; LETTERDOBJ; DOCTORIOBJ) >

14. What evidence is there? • Theoretical linguistics: • Substantial theoretical backing for level of structure defining hierarchical/linear relationships between abstract categories (phrase structure). • Speech errors: • Sound exchanges: caught tourses (taught courses), poppy of my caper (copy of my paper) • Distance constraints: Garrett (1980) found 87% originate within same phrase. • Pausing/intonation data: • Correlation between pauses and phrase structure. E.g., Grosjean, Grosjean & Lane (1979)

15. Syntactic priming • Experimental evidence for abstract syntactic processing: syntactic priming (aka structural persistence) effects. • Basic observation: • Speakers repeat syntax in spontaneous speech. • Schenkein (1980): A: Cor, the noise downstairs, you’ve got to hear and witness it to realise how bad it is. B:You have got to experience exactly the same position as me, mate, to understand how I feel.

16. More examples • Levelt & Kelter (1982): • A: What time do you close? B: Six o’clock • A: At what time do you close? B: At six o’clock • Interpretational problems: • Lexical repetition • Question-answer sequences

17. Why is this interesting? • Priming effects: • Processing one stimulus is affected by prior processing of another, related stimulus. e.g., NURSE - DOCTOR vs BREAD – DOCTOR DOCTOR is faster after NURSE than after BREAD

18. The logic of priming • Depends upon processor recognising relationship between two stimuli: informative about representation. • Respond faster to DOCTOR after processing NURSE because using some of same representations/procedures. • DOCTOR and NURSE are related (only) in meaning. • Therefore, some aspect of lexical processing is concerned with meaning.

19. Priming and representation • Priming experiments • Process stimulus with particular characteristics. • Process subsequent stimulus which is related along only one dimension. • If priming effect found (residual activation from processing first stimulus affects processing of second), then: • Processor must be sensitive to that dimension of structure. • So, if production involves stage of abstract syntactic representation, should find priming effects based upon syntactic structure.

20. Experimental demonstrations • Bock (1986) • Running recognition memory task: • Subjects make recognition decision for stimuli. • Ostensibly to aid memory, subjects repeat sentences and describe pictures. • Repeated sentences = primes • Picture descriptions = targets

21. Bock (1986) • Example trial: • Subject repeats sentence: The rock star sold some drugs to the undercover agent [Prepositional Object] • Makes recognition decision: No • Subject describes picture of girl handing paintbrush to man standing on stepladder: The girl is handing a paintbrush to the man [Prep Object] The girl is handing the man a paintbrush [Double Object]

22. Bock (1986) • Tendency to repeat structure: • After repeating active sentence, produce active description; • After repeating passive, produce passive; • After repeating Prepositional Object [PO] (verb something to someone), produce PO; • After repeating Double Object [DO] (verb somebody something), produce DO. • The rock star sold the undercover agent some cocaine > The girl gives the man the brush • No open class (= content) words in common.

23. Excluding other explanations • Based on repetition of closed class words? e.g. by in passives, to in PO • Bock (1989): The secretary baked the cake for the boss The secretary gave the cake to the boss > The girl is handing the brush to the man - Hence, representations not specified for open class or closed class words

24. Bock & Loebell (1990) • Based upon event roles? • Primes and targets involving ‘same’ (?) syntax but different roles: • By-phrase can specify location or agency (who did action) The foreigner was loitering by the traffic light > The boy is being woken by the alarm clock • Based upon metrical structure? • Primes and targets involving different syntax but same metrical structure: * Susan bought the book to study Susan brought the book to Stella > The girl gives the brush to the man

25. What are positional representations? • Bock & colleagues: • Abstract - not specified for lexical content; • Specified for syntactic category. • ‘Hierarchical configurations of sentences’

26. Features of positional representations • Pickering & Branigan (1998): • Sentence completion task PRIME: The bus driver gave the change…to the passenger Or: The bus driver gave the passenger…a ticket TARGET: The surgeon handed… …the nurse the scalpel (DO) …the scalpel to the nurse (PO) …out leaflets (Other)

27. Features of positional representations • Manipulations of verb form: • Same vs different tense (hands/handed) • Same vs different number (hands/hand) • Same vs different aspect (hands/is handing)

28. Results • Priming occurred whether verb varied or not between prime and target; • But stronger effects if verb remained the same. • Changing the form of the verb didn’t affect priming: • Give  gave (tense) • Was giving  gave (aspect) • Gives  give (number) • So the syntactic representations aren’t specified for verb form.

29. NP_NP combination NP_PP Verb Syntactic category GIVE Lexical repetition effect • Pickering and Branigan (1998) • Priming is tied to a syntactic rule • syntactic rules are linked to verb lemmas • repeating a verb increases priming • Lemma Stratum: encodes syntactic information - GIVE is linked to a PO rule and a DO rule

30. Features of positional representations (2) • Theoretical linguistics: • Phrase Structure rules define local trees: • Mother node and daughter node • E.g. VP -> V NP PP

31. Features of positional representations (3) • Positional representations defined in terms of local trees: • Bigger and smaller structure not specified. • Does priming occur over local trees? • Pickering & Branigan (1998): • PO primes PO, DO primes DO – irrespective of the structure of NPs. • e.g. The postman gave the letter to the doctor > The surgeon gave the sharp scalpel to the nervous nurse

32. Local trees

33. Local trees (2) • Branigan, Pickering, McLean & Stewart (2004): • Varied the syntactic context of the prime and target: • The man knew that the postman handed the boy the parcel > The surgeon handed the nurse the scalpel • The postman handed the boy the parcel > The consultant suspected that the surgeon handed the nurse the scalpel • Priming occurred despite changes in context – so the same processes are involved in producing main and embedded clauses

34. Pickering, Branigan & McLean (2002) • Two possible models of syntax: • S -> NP VP • encodes dominance relations (S is mother of NP and VP – higher in the tree) • encodes linear precedence relations (NP precedes VP in word order) • During production, constituent structure could be generated in one stage or in two stages.

35. Two models • One-stage model: • Phrases are assembled into structure that is specified for both phrasal composition and linear order: • S -> NP VP • Two-stage model: • Dominance relations are defined at first stage, then at subsequent stage placed in linear order: • Dominates(S,NP,VP) • NP < VP

36. Heavy NP Shift • PO: • The girl gave the wet paintbrush to the man • V NP PP • Shifted: • The girl gave to the man the wet paintbrush • V PP NP • DO: • The girl gave the man the wet paintbrush • V NP NP • PO and Shifted have exactly same constituents, but in different order.

37. Method • Spoken and written sentence completion: • The girl gave the man… (DO) • The girl gave the paintbrush…(PO) • The girl gave to the man... (Shifted) • Target: • The teacher gave…

38. Predictions • If processing is one-stage, shifted and PO structures do not involve the same procedures/representations: • they involve different phrase structure rules • VP -> V NP PP (PO) • VP -> V PP NP (Shifted) • Therefore, shifted sentences should not prime PO sentences: • they have nothing in common

39. Predictions (2) • If it is two-stage, shifted and PO structures involve some of the same procedures/representations: • they involve the same dominance rules (though different linear precedence rules) • dominates(VP,V,NP,PP) • V < NP < PP (PO) • V < PP < NP (shifted) • Therefore, shifted sentences should prime PO sentences: • they have dominance relations in common

40. Results • Proportion of PO targets/condition: • PO prime .70 • DO prime .46 • Shifted prime .59 • Baseline prime .62 • Subjects produced significantly more POs after PO prime - but not after Shifted prime • Shifted prime behaved like Baseline

41. Conclusions • Results are compatible with one-stage model: • when producing sentence, fully-specified constituent structure is determined. • both dominance (vertical relations in tree) and order (horizontal relations in tree) are specified. • No evidence for separate linearisation process.

42. Summary • Functional processing • Unordered representations • Assignment of grammatical functions • Influenced by conceptual factors (next week!) • Positional processing: • Ordered representations. • Capture local syntactic relations. • Specified for grammatical category: • not open or closed class lexical content. • Fully specified for hierarchical structure/linear order. • Not subject to conceptual influences.