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Stable Heteroclinic Sequences as a Paradigm for Dynamic Psycholinguistics. ZAS Tandem Workshop December, 11 – 13, 2010. Peter beim Graben Department of German Language and Linguistics Humboldt-Universität zu Berlin peter.beim.graben@hu-berlin.de. Overview. linguistic ambiguity
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Stable Heteroclinic Sequences as a Paradigm for Dynamic Psycholinguistics ZAS Tandem Workshop December, 11 – 13, 2010 Peter beim Graben Department of German Language and Linguistics Humboldt-Universität zu Berlin peter.beim.graben@hu-berlin.de
Overview • linguistic ambiguity • geometric representations • heteroclinic dynamics • disambiguation by bifurcation
Linguistic Ambiguity (1) The forester watched the bird with binoculars. (2) The bird watched the forester with binoculars.
PP Attachment instrumentalattributive semantic biases
Context Free Grammar (1) instrumental: (2) attributive:
state description Syntactic Parsing bottom-up architecture
Sequence Generation 1 2 3 4 6 8 10
Filler / Role Binding filler: categories represented by vectors roles: vectors Smolensky & Legendre (2006) beim Graben et al. (2008) beim Graben & Potthast (2009)
Tensor Product Representation 1. tree 2. parser state description p3p2p1 : stack position roles
Tensor Product Parser instrumental attributive
State Descriptions stationary states are “vertices” in state space
Saddle Node saddle unstable manifold stable manifold
Saddle Node saddle unstable manifold stable manifold
Stable Heteroclinic Sequence SHS Afraimovich et al. (2004) Rabinovich et al. (2008)
ith stationary pattern (“factor”) Order Parameters amplitude of ith pattern (“load”) Haken (1983) beim Graben et al. (2009)
Order Parameter Dynamics network of competing neural populations 1 5 2 generalized Lotka-Volterra model 4 3
Sequence Generation 1 2 3 4 6 8 10
Disambiguation by Bifurcation unstable fixpoints
Disambiguation by Bifurcation new unstable fixpoints
Control Parameter convex combination instrumental: attributive:
Bifurcation Scenario 1 2 3 4 6 8 10
Bifurcation Scenario 1 2 3 5 7 9 11
Conclusion • complex symbolic data structures geometrically represented by tensor products • syntactic parsing represented by time-discrete sequences in geometric space • continuous time through competitive order parameter dynamics • representational states as saddle nodes connected through stable heteroclinic sequences • syntactic reanalysis as bifurcation of SHS
Acknowledgements Thank you for your attention! Funding: DFG-Heisenbergstipendium GR 3711/1-1