Interactivity in lexical access

1. Interactivity in lexical access The modularity debate

2. Outline • Modularity: who cares anyway? • Discreteness in production • ‘maximalism’ and ‘minimalism’ • Discreteness in the Levelt et al. theory • Arguments for discrete stages in lexical access • Arguments against it.

3. Modularity • Fodor (1983): • Central systems and Input systems (modules) • Modules: • Domain specific (color perception, parsing) • Mandatory (You’re mad if you read this!) • Limited central access (tree structure rapidly gone) • Fast (reflex-like) • Informationally encapsulated (no feedback) • Shallow outputs (only necessary information)

4. Does production consist of modules? • Fodor: ‘language’ is a module • Hidden assumption in many current theories: • Language production consists of a series of stages / levels, each of which is a module • Stages discovered using the Donders / Sternberg additive factors logic

5. Additive factors logic • Suppose you manipulate variable X (e.g., animacy) and variable Y (e.g., frequency) let’s say in picture naming. • If there are main effects of X and Y, but there is no interaction -> they affect separate stages. • If X and Y show main effects and interact, -> they affect the same stage.

6. Minimalism • Minimal input: a process occurring at stage n, will pass to stage n+1 only the minimal, necessary information (cf. Fodor, ‘shallow output’). • Unidirectional information flow: level n will pass information to level n+1, but level n+1 does not send information back to n.

7. Levelt et al.’s maximalism • 1. Lemma retrieval is NOT minimal: • Maximal input: lemmas get activation from all activated lexical concepts. • Bidirectionality: lemmas activate lexical concepts.

8. Levelt et al.’s minimalism • 2. Word-form retrieval IS minimal: • Minimal input: The selected lemma and only the selected lemma, will send activation to the word forms (the assumption of non-cascading). • Unidirectional flow: the word form does not send activation back to the lemma.

9. Why is word-form retrieval minimal (1)? • Parsimony (‘Occam’s razor): a theory should minimize its assumptions (theoretical constructs, ad-hoc mechanisms). • Thus, it is better to have a theory without cascading and without feedback, if the data don’t force us to.

10. Why is word-form retrieval minimal (2)? • The alternative is not logical. If the lemmas which are active but which are not selected activate their word forms, this will hinder the encoding of the target. • Thus, to preserve accuracy, special mechanisms would be needed to prevent this hindrance. • A ‘baroque’ theory.

11. Why is word-form retrieval minimal (3)? • Levelt et al. (1991). Picture naming + auditory probe (SOA = 73 ms) • Lexical decision on the probe. Is it word or a nonword? • Latencies corrected with condition without picture.

12. Why is word-form retrieval minimal (3-ii)? • One experiment: Target Sheep, probes Sheet and Pen. Faster lexical decision for Sheet. • Crucial experiment: Semantic, Identical, Phonologically related to semantic, unrelated: Sheep, goat, goal, pen. • Sem = Id >> PhtoS = Unr

13. Why is word-form encoding minimal? (4) • There is no reaction time evidence for this (i.e., from word form to lemma selection) proposed feedback mechanism (Levelt et al., 1999, p. 17) • To anticipate: that claim is controversial. Levelt et al. have a different explanation.

14. Why is word-form encoding maximal? (max input 1) • Peterson & Savoy (1998): similar paradigm as Levelt et al. (1991), naming iso LD • Near Synonyms: couch and sofa • After naming a picture as a COUCH, there was priming for the naming of the word SODA. • Only for near-synonyms.

15. Why is word-form encoding maximal? (max input 2) • Cutting and Ferreira (1998): Picture/word interference. • Target Picture: Ball (like in football). • Distractor: Dance (sem. related to homophone): Facilitation • (Dance activates lemma Ball, and both Ball-lemmas activate the word form)

16. Why is word form retrieval maximal? (max input 3) • Blends: it didn’t bother me in the sleast … slightest [presumably: least and slightest; Boomer & Laver, 1968]. • Often near-synonyms, partially encoded in one utterance. • Both lemmas spread activation to the form level.

17. Why is word form retrieval maximal? (max input 4) • Mixed erors occur more often than chance would predict (Dell & Reich, 1981) • Rat -> Cat; Oyster -> Lobster • Why? • Form-to-lemma feedback yields semantic error (traditional account) • Cascading yields phonological error (V & H)

18. Why is word form retrieval maximal? (bidirectionality 1) • Starreveld & LaHeij (1995) -- Picture/word interference • Distractors: semantic, phonological, semantic AND phonological, unrelated. • Target: CAT, Distractors: Sheep, Car, Calf, Pen. • Sem interference and Phonological facilitation; PLUS AN INTERACTION.

19. Why is word form retrieval maximal? (bidirectionality 1-i) • Thus, the semantic interference effect for the mixed case (CALF) was smaller than what you’d get if you add up the semantic and phonological effects. • Note: their interpretation: the lemma does not exist (cf. Caramazza & Miozzo, 1997).

20. Why is word form retrieval maximal? (bidirectionality 2) • Damian & Martin (1999, Expt 3). • Similar to Starreveld & LaHeij, but with auditory distractors. • Again, a clear interaction between form and meaning. • Their interpretation: feedback

21. Why is word form retrieval maximal? (bidirectionality 3) • Harley & Brown (1998) • TOT states: more likely for words in a low density neighbourhood. • Recall, that often some phonological info available. The more word forms compatible with it, the more feedback they can send to the lemma.

22. The Levelt et al. reply • Blends, near-synonym effects: special mechanism: selection of 2 lemmas. • Extension of this mechanism to other cases • Self-monitoring mechanisms (mixed errors more difficult to edit out) • Input account.

23. Back to Fodor... • “The claim that input systems are informationally capsulated must be very carefully distinguished from the claim that there is top-down information flow within these systems” (p. 76).