Gestural overlap and self-organizing phonological contrasts
Contrast in Phonology, University of TorontoMay 3-5, 2002
Alexei KochetovHaskins Laboratories/Yale University
Thanks to
• The Project on Contrast in Phonology– SSHRC grants (410-99-1309 and 410-96-0842)
to Elan Dresher and Keren Rice, University of Toronto
– http://www.chass.utoronto.ca/~contrast
Introduction
• Restrictions on phonological contrasts– Backness and rounding in high vowels– Secondary articulations in consonants
• Account: – These markedness effects emerge from low-
level speaker-listener/learner interactions – The crucial role of production and perception of
contrasts
Phonological contrasts
• Focus:– Contrasts in high vowels
• Front/back, rounded/unrounded
• Inventories /i y u/, /i y u/, or /i u/
– Contrasts in consonant secondary articulations• Palatalized vs. non-palatalized: /C C(/w)/
• Labialized vs. non-labialized: /Cw C(w/)/
• Velarized vs. non-velarized: /C C()/
Observations
• Languages with multiple vowel contrasts avoid distinctions in secondary consonant articulations– e.g. /y/ but */Cj/ (C = plosive; 2 exceptions)
Observations
• Languages with distinctive secondary articulation contrasts tend to avoid multiple vowel contrasts, particularly distinctions in rounding/backness– e.g. /Cw/ but */y/ (C = plosive; 1 exception)
Observations
• Inventories of languages of Northern and Eastern Europe – 37 languages (Celtic, Germanic, Baltic, Uralic
and Turkic)
Explanation
• Approach 1– These markedness effects are pre-specified in
Universal Grammar• Harmonic rankings of constraints (Optimality
Theory; Prince & Smolensky 1993)
• Phonological representations
• Approach 2– These markedness effects arise due to lower-
level factors -- limitations on production and perception
– Work in phonology and phonetics: • Browman & Goldstein 1986, 2002; Ohala 1981;
Hume & Johnson 2001, Pierrehumbert, Beckman, & Ladd 2001, among others
• Cf. Jackendoff 2002 on markedness in general
Explanation
Explanation
• Approach 2– These markedness effects arise due to lower-
level factors -- limitations on production and perception
– Work in phonology and phonetics: • Browman & Goldstein 1986, 2002; Ohala 1981;
Hume & Johnson 2001, Pierrehumbert, Beckman, & Ladd 2001, among others
• Cf. Jackendoff 2002 on markedness in general
Explanation
• Approach 2– Self-organization, or spontaneous emergence of
order (see e.g., Kauffman 1995)
• dynamic systems
• AI and ALife (see e.g., Pfeifer & Scheier 2001)
Self-organization and phonology
• Markedness effects• Unmarked:
– stable with respect to production and/or perception, and/or higher-level processing
– An equilibrium position
• Marked: – unstable with respect to production, and/or perception,
and and/or higher-level processing
– A non-equilibrium position
Simulation
• Speaker-listener/learner interactions
• Autonomous agents – Cf. Browman & Goldstein 1999, de Boer 2000,
Lieberman 2000, Harrison, Dras & Kapicioglu 2002
A hypothetical language
• Language X
• Inventory: – {i y u} – {C C C C}
• Lexicon: – C1VC2 words, where C1= C2
– 16 items
Language X
#
C CiC CyC C C CuC 4
C C iC C yC C C C uC 4
C CiC CyC C C CuC 4
C C iC C yC C C C uC 4
# 4 4 4 4
Lexical items
Speaker-listener interactions
Agent A Agent B
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
* From www.zabaware.com
*
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Speaker-listener interactions
Signal Production Perception
Lexicon and
Grammar
Lexicon and
Grammar
Signal Perception Production
Agent A Agent B
Production
• Articulatory synthesizer (Maeda 1989, Vallée1994)
• Articulatory gestures (targets)
• Vectors of numbers between 0 and 1– Backness [0 . . . 1]– Height [0 . . . 1]– Rounding [0 . . . 1]
Production: Gestural overlap
• Gestures have conflicting targets
• Physical limits on how well targets can be attained
• An “undershoot” of at least one of the gestures (Lindblom 1963)
• Stiffness (GEST, Computational gestural model; Browman & Goldstein 1990)
Production: Gestural overlap
• Stiffness, kC = 1, kV = 1;
• No reduction; physically impossible
C V C
Production: Gestural overlap
• Evidence: – In languages with secondary articulation
vowels are strongly affected by the secondary articulation quality of neighboring consonants
– Russian (Bolla 1981, Kochetov 2001)– Irish (Ó Dochartaigh 1992 ) – Marshallese (Choi 1992)
Production: Gestural overlap
• Stiffness, kC = 0.75, kV = 1• Consonant gestures (secondary articulation) are
reduced
C V C
Production: Gestural overlap
• Evidence: – In languages with multiple backness and
rounding contrasts consonants are often allophonically palatalized and velarized/labialized
– Turkic languages (Comrie 1981)
Simulation
• Item: CuC • Case 1: Vowel gesture is
reduced– kC = 1, kV = 0.5
• Case 2: Consonant gestures are reduced– kC = 0.5, kV = 1
Case 1: Lexicon and grammar
Agent A
#
C CiC CyC C C CuC 4
C C iC C yC C C C uC 4
C CiC CyC C C CuC 4
C C iC C yC C C C uC 4
# 4 4 4 4
Case 1: Lexicon and grammar
Agent B
#
C CiC CyC C C *CuC 3
C C iC C yC C C *C uC 3
C *CiC CyC C C CuC 3
C *C iC C yC C C C uC 3
# 2 4 4 2
Case 1: Lexicon and grammar
Agent B
#
C CiC *CyC C C *CuC 2
C *C iC C yC C C *C uC 2
C *CiC CyC C C *CuC 2
C *C iC C yC *C C C uC 2
# 1 3 3 1
Case 1: Lexicon and grammar
• Default grammar 1: – limited vowel contrasts (front vs. back)– multiple consonant contrasts in secondary
articulation (restricted in distribution)
Case 2: Lexicon and grammar
Agent A
#
C CiC CyC C C CuC 4
C C iC C yC C C C uC 4
C CiC CyC C C CuC 4
C C iC C yC C C C uC 4
# 4 4 4 4
Case 2: Lexicon and grammar
Agent B
#
C CiC CyC *C C *CuC 2
C C iC C yC C C C uC 4
C CiC CyC C C CuC 4
C *C iC *C yC C C C uC 2
# 3 3 3 3
Case 2: Lexicon and grammar
Agent B
#
C CiC *CyC *C C *CuC 1
C *C iC C yC C C C uC 3
C CiC CyC C C *CuC 3
C *C iC *C yC *C C C uC 1
# 2 2 2 2
Lexicon and grammar
• Default grammar 2: – multiple vowel contrasts (restricted in
distribution)– limited consonant contrasts in secondary
articulation (front vs. back)– consonants realizations are often close to
neutral (non-palatalized, non-labialized, etc.)
Lexicon and grammar
• Default grammar 3: – limited vowel contrasts– limited consonant contrasts in secondary
articulation
Conclusion
• The incompatibility of vowel and secondary articulation contrasts emerges through speaker-listener/learner interactions – Unstable (marked) Stable (unmarked)
• No reference to pre-specified “knowledge” of markedness
Limitations
• The simulation does not explain certain segmental markedness effects – e.g. /y/ is more marked than /i/– // is more marked than /u/
• Markedness is a by-product of multiple factors
Further directions
• Implementation: additional factors– Other sequences, primary place of articulation
– More realistic production and perception
– More complex generalizations across the Lexicon and Grammar
– Higher-level processing: morphological structure and alternations
– Multiple agents: speakers/listeners
• Other phonological contrasts