psy 369: psycholinguistics language production: models

PSY 369: Psycholinguistics

Language Production:Models

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

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

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

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)

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)

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?

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)

Message

Lexicon

Grammatical

Form

Articulation

FunctionalProcessing

PositionalProcessing

Network has three strata conceptual stratum

lemma stratum

word-form stratum

Message

Lexicon

Grammatical

Form

Articulation

FunctionalProcessing

PositionalProcessing

Levelt’s model

Tip of tongue state when lemma is retrieved without word-form being retrieved

Message

Lexicon

Grammatical

Form

Articulation

FunctionalProcessing

PositionalProcessing

Levelt’s model

Formulation involves lexical retrieval:

Semantic/syntactic content (lemma)

Phonological content (word-form)

has stripes is dangerous

TIGER (X)

Fem.

Noun countable

tigre

/tigre/

/t/ /I/ /g/

Lexical concepts

Lemmas

Lexemes

Phonemes

Levelt’s model

Lexicon

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)

First, lemma activation occurs This involves activating a

lemma or lemmas corresponding to the concept

thus, concept TIGER activates lemma “tiger”

Lexical selection

Fem.

Noun countable

tiger

TIGER (X)

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

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

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/

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

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

Semantically related words can interfere with naming e.g., the word TIGER in

a picture of a LION

Basic findings

tiger

However, form-related words can speed up processing e.g., the word liar in a

picture of a LION

Basic findings

liar

Experiments manipulate timing: picture and word can be presented

simultaneously

time

liar

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

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

Schriefers, Meyer, and Levelt (1990)

Auditory presentation of distractors DOT phonologically related CAT semantically related SHIP unrelated word

500520540560580600620640660680700

-150 0 150

DOTCATSHIP

EarlyOnly Semantic effects

Schriefers, Meyer, and Levelt (1990)

Auditory presentation of distractors DOT phonologically related CAT semantically related SHIP unrelated word

500520540560580600620640660680700

-150 0 150

DOTCATSHIP

LateOnly Phonological effects

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

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)

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

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

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

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

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

Alternatively, it simply serves to increase fluency in lemma selection advantageous to select a lemma whose

phonological form is easy to find

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)

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?

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

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)

Results

Relatedness -150 ms 0 ms + 150 ms

Unrelated 670 702 691

Semantic 702 733 697

Phono. 665 683 646

S & P 679 676 654

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

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.

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

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

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

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.)