Presentation is loading. Please wait.

Presentation is loading. Please wait.

PSY 369: Psycholinguistics Language Production: Models.

Similar presentations


Presentation on theme: "PSY 369: Psycholinguistics Language Production: Models."— Presentation transcript:

1 PSY 369: Psycholinguistics Language Production: Models

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

3 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 Tip-of-the-tongue

4 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? Tip-of-the-tongue

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

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

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

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

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

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

15 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 Lemma selection tiger TIGER (X)LION (X) 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 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 Model’s assumptions

18 tiger 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 Experimental tests

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

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

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

22 Experiments manipulate timing: picture and word can be presented simultaneously liar time liar 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 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 Interpretation

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 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 Evidence for Dell’s model

30 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 Dell’s explanation

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 hat dog DOG (X)CAT (X) cat /cat//hat/ /t//a//k//h/ Found no evidence for it

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 Relatedness-150 ms0 ms+ 150 ms Unrelated670702691 Semantic702733697 Phono.665683646 S & P679676654

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.)


Download ppt "PSY 369: Psycholinguistics Language Production: Models."

Similar presentations


Ads by Google