PSY 369: Psycholinguistics

1. PSY 369: Psycholinguistics Language Production: Models

2. Tip-of-the-tongue • TOT • Meaning access • No (little) phonological access • What about syntax? Uhh… It is a.. You know.. A.. Arggg. I can almost see it, it has two Syllables, I think it starts with A …..

3. Tip-of-the-tongue • Semantics • Syntax • grammatical category (“part of speech”) • e.g. noun, verb, adjective • Gender • e.g. le chien, la vache; le camion, la voiture • Number • e.g. dog vs. dogs; trousers vs. shirt • Count/mass status • e.g. oats vs. flour

4. Tip-of-the-tongue • Vigliocco et al. (1997) • Subjects presented with word definitions • Gender was always arbitrary • If unable to retrieve word, they answered • How well do you think you know the word? • Guess the gender • Guess the number of syllables • Guess as many letters and positions as possible • Report any word that comes to mind • Then presented with target word • Do you know this word? • Is this the word you were thinking of?

5. Vigliocco et al (1997) • Scoring • + TOT • Both reported some correct information in questionnaire • And said yes to recognition question • - TOT • Otherwise • Vigliocco et al. (1997)

6. Vigliocco et al (1997) • Results • + TOT: 84% correct gender guess • - TOT: 53% correct gender guess • chance level • Conclusion • Subjects often know grammatical gender information even when they have no phonological information • Supports split between syntax and phonology in production • Vigliocco et al. (1997)

7. Comparing models • Central questions: • Are the stages discrete or cascading? • Discrete: must complete before moving on • Cascade: can get started as soon as some information is available • Is there feedback? • Top-down only • Bottom up too • How many levels are there?

8. Levelt’s model • Four broad stages: • Conceptualisation • deciding on the message (= meaning to express) • Formulation • turning the message into linguistic representations • Grammatical encoding (finding words and putting them together) • Phonological encoding (finding sounds and putting them together) • Articulation • speaking (or writing or signing) • Monitoring (via the comprehension system)

9. Levelt’s model • Network has three strata • conceptual stratum • lemma stratum • word-form stratum

10. Levelt’s model • Tip of tongue state when lemma is retrieved without word-form being retrieved • Formulation involves lexical retrieval: • Semantic/syntactic content (lemma) • Phonological content (word-form)

11. Levelt’s model has stripes is dangerous Lexical concepts TIGER (X) Lexicon Noun countable tigre Lemmas Fem. Lexemes /tigre/ /t/ /I/ /g/ Phonemes

12. Conceptual stratum • Conceptual stratum is not decomposed • one lexical concept node for “tiger” • instead, conceptual links from “tiger” to “stripes”, etc. has stripes is dangerous TIGER (X)

13. Lexical selection • First, lemma activation occurs • This involves activating a lemma or lemmas corresponding to the concept • thus, concept TIGER activates lemma “tiger” TIGER (X) Noun countable tiger Fem.

14. Lexical selection • First, lemma activation occurs • This involves activating a lemma or lemmas corresponding to the concept • thus, concept TIGER activates lemma “tiger” TIGER (X) LION (X) tiger lion • But also involves activating other lemmas • TIGER also activates LION (etc.) to some extent • and LION activates lemma “lion”

15. Lemma selection • Selection is different from activation • Only one lemma is selected • Probability of selecting the target lemma (“tiger”) • ratio of that lemma’s activation to the total activation of all lemmas (“tiger”, “lion”, etc.) • Hence competition between semantically related lemmas TIGER (X) LION (X) tiger lion

16. Morpho-phonological encoding(and beyond) • The lemma is now converted into a phonological representation • called “word-form” (or “lexeme”) • If “tiger” lemma plus plural (and noun) are activated • Leads to activation of morphemes tigre and s • Other processes too • Stress, phonological segments, phonetics, and finally articulation /tigre/ /t/ /I/ /g/

17. Model’s assumptions • Modularity • Later processes cannot affect earlier processes • No feedback between the word-form (lexemes) layer and the grammatical (lemmas) layer • Also, only one lemma activates a word form • If “tiger” and “lion” lemmas are activated, they compete to produce a winner at the lemma stratum • Only the “winner” activates a word form • The word-forms for the “losers” aren’t accessed

18. Experimental tests • Picture-word interference task • Participants name basic objects as quickly as possible • Distractor words are embedded in the object • participants are instructed to ignore these words tiger

19. Basic findings • Semantically related words can interfere with naming • e.g., the word TIGER in a picture of a LION tiger

20. Basic findings • However, form-related words can speed up processing • e.g., the word liar in a picture of a LION liar

21. liar • Experiments manipulate timing: • picture and word can be presented simultaneously time

22. Experiments manipulate timing: • picture and word can be presented simultaneously liar liar time • or one can slightly precede the other • We draw inferences about time-course of processing

23. Schriefers, Meyer, and Levelt (1990) • SOA (Stimulus onset asynchrony) manipulation • -150 ms (word …150 ms … picture) • 0 ms (i.e., synchronous presentation) • +150 ms (picture …150ms …word) • Auditory presentation of distractors • DOT phonologically related • CAT semantically related • SHIP unrelated word

24. Schriefers, Meyer, and Levelt (1990) • Auditory presentation of distractors • DOT phonologically related • CAT semantically related • SHIP unrelated word Early Only Semantic effects

25. Schriefers, Meyer, and Levelt (1990) • Auditory presentation of distractors • DOT phonologically related • CAT semantically related • SHIP unrelated word Late Only Phonological effects

26. Interpretation • Early semantic inhibition • Late phonological facilitation • Fits with the assumption that semantic processing precedes phonological processing • No overlap • suggests two discrete stages in production • an interactive account might find semantic and phonological effects at the same time

27. Dell’s interactive account • Dell (1986) presented the best-known interactive account • other similar accounts exist • 3 levels of representation • semantics (decomposed into features) • words • phonemes (sounds)

28. Interactive because information flows “upwards” as well as “downwards” • e.g., the semantic features mammal, barks, four-legs activate the word “dog” • this activates the sounds /d/, /o/, /g/ • these send activation back to the word level, activating words containing these sounds (e.g., “log”, “dot”) to some extent • this activation is upwards (phonology to syntax) and wouldn’t occur in Levelt’s account

29. Evidence for Dell’s model • Mixed errors • Both semantic and phonological relationship to target word • Target = “cat” • semantic error = “dog” • phonological error = “hat” • mixed error = “rat” • Occur more often than predicted by modular models • if you can go wrong at either stage, it would only be by chance that an error would be mixed

30. Dell’s explanation • The semantic features of dog activate lemma “cat” • Some features (e.g., animate, mammalian) activate “rat” as well • “cat” then activates the sounds /k/, /ae/, /t/ • /ae/ and /t/ activate “rat” by feedback • this confluence of activation leads to increased tendency for “rat” to be uttered • Also explains the tendency for phonological errors to be real words • Sounds can only feed back to words (non-words not represented) so only words can feedback to sound level

31. Why might interaction occur? • Can’t exist just to produce errors! • So what is feedback for? • Perhaps because the same network is used in comprehension • So feedback would be the normal comprehension route • Alternatively, it simply serves to increase fluency in lemma selection • advantageous to select a lemma whose phonological form is easy to find

32. Schriefers, Meyer, and Levelt (1990) • Also looked for any evidence of a mediated priming effect DOG (X) CAT (X) dog cat hat /cat/ /hat/ • Found no evidence for it /k/ /a/ /t/ /h/

33. Alternatively, it simply serves to increase fluency in lemma selection • advantageous to select a lemma whose phonological form is easy to find

34. Evidence for interactivity • A number of recent experimental findings appear to support interaction under some circumstances (or at least cascading models) • Peterson & Savoy (JEP:LMC, 1998) • Cutting & Ferreira (JEP:LMC, 1999) • Griffin & Bock (JML, 1998) • Damian & Martin (JEP:LMC, 1999)

35. Peterson & Savoy found evidence for phonological activation of near synonyms: • Participants slower to say distractor soda than unrelated distractor when naming couch • Soda is related to non-selected sofa • remember that Levelt et al. assume that only one lemma can be selected and hence activate a phonological form • Levelt et al’s explanation: Could be erroneous selection of two lemmas?

36. Damian and Martin (1999) • Extension of Schriefers et al.’s picture-word interference task • remember that semantic inhibition occurred early, phonological facilitation occurred late (with no overlap) • various methodological changes and developments • focus on Experiment 3

37. The critical difference from Schriefers et al. is the addition of a “semantic and phonological” condition • Picture of Apple • peach (semantically related) • apathy (phonologically related) • apricot (sem & phono related) • couch (unrelated) • (also no-word control, always fast)

38. Results

39. Summary of findings • early semantic inhibition (- 150 and 0 ms) • late phonological facilitation (0 and + 150 ms) • shows overlap, unlike Schriefers et al. • but S & P condition didn’t show early semantic inhibition

40. This last finding demonstrates that semantic interference is reduced in the simultaneous presence of a phonological relationship (which should facilitate) • Thus the finding appears to contradict the “discrete two-step” account of Levelt et al.

41. Can the two-stage account be saved? • Evidence for interaction is hard to reconcile with the Levelt account • however, most attempts are likely to revolve around the monitor • basically, people sometimes notice a problem and screen it out • Levelt argues that evidence for interaction really involves “special cases”, not directly related to normal processing

42. Summary • Levelt et al.’s theory of word production: • Strictly modular lexical access • Syntactic processing precedes phonological processing • Dell’s interactive account: • Interaction between syntactic and phonological processing • Experimental evidence is equivocal, but increasing evidence that more than one lemma may activate associated wordform

43. Caramazza’s alternative • Caramazza and colleagues argue against the existence of the lemma node • instead they propose a direct link between semantic level and lexeme • syntactic information is associated with the lexeme • Also assumes separate lexemes for written and spoken production • This is really a different issue

44. Much evidence comes from patient data • But also evidence from the independence of syntactic and phonological information in TOT states • see discussion of Vigliocco et al. • also Caramazza and Miozzo (Cognition, 1997; see also replies by Roelofs et al.)