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PS: Introduction to Psycholinguistics. Winter Term 2005/06 Instructor: Daniel Wiechmann Office hours: Mon 2-3 pm Email: daniel.wiechmann@uni-jena.de Phone: 03641-944534 Web: www.daniel-wiechmann.net. Session 5: Understanding the structure of syntax. Task: Parsing
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PS: Introduction to Psycholinguistics Winter Term 2005/06 Instructor: Daniel Wiechmann Office hours: Mon 2-3 pm Email: daniel.wiechmann@uni-jena.de Phone: 03641-944534 Web: www.daniel-wiechmann.net
Session 5:Understanding the structure of syntax • Task: Parsing • Assign syntactic structure to incoming string of words • Peter gave Mary the book • N V N Det N • S[NP[N] VP[V NP[N] NP[Det N]]]
Session 5:Understanding the structure of syntax • How does parsing operate? • Why are some sentences more difficult to parse than others? • What happens to the syntactic representation after parsing? • How many stages of parsing are there?
Session 5:Understanding the structure of syntax • What happens if there is a choice of possible structures at any point? • At what stage is non-structural information information used? • Is there an enclosed (autonomous) syntactic processor (module)?
Session 5:Understanding the structure of syntax • Assumptions: • Our knowledge of Grammar (and, therefore, phrase structure) provides us with “templates” for sentence structure • As we hear sentences, we assign incoming words to phrases and phrases to nodes in these templates
Session 5:Understanding the structure of syntax • Psycholingists usually represent the parsing process as the on-line construction of PS-trees • S -> NP + VP • NP -> (Det) + N • VP -> V + (NP)
Session 5:Understanding the structure of syntax • Early ideas about parsing (Fodor, Bever, and Garrett, 1974) • First, we identify words on the basis of perceptual data • Recognition and lexical access give access to syntactic category of a given word • We then use this information to build up a parse tree for each clause • Finally we use parse tree to generate semantic representaion
Session 5:Understanding the structure of syntax • Incremental parsing: • Language processor operates incrementally, i.e. it rapidly constructs a syntactic analysis for a sentence fragment, assigns it a semantic interpretation, and relates this interpretation to world knowledge
Session 5:Understanding the structure of syntax • Standing syntactic ambiguity • I saw the Alps flying to Romania • Peter said that Mary finished it yesterday
Session 5:Understanding the structure of syntax • Local syntactic ambiguity • The log floated past the bridge sank • The old man the boats • Since Jay always jogs a mile seems like a very short distance to him
Session 5:Understanding the structure of syntax • Kimball (1973) • Structures are built guided by rules that are based on that are based on psychological constraints such as minimizing memory load
Session 5:Understanding the structure of syntax • Kimball (1973): Seven principles • Top-down-parsing (predict constituents) • Right association • New nodes • Two nodes • Closure • Fixed structure • Processing
Session 5:Understanding the structure of syntax • The sausage machine (Frazier and Fodor 1978) • Two-stage model • Preliminary phrase packager (PPP) • Sentence structure supervisor (SSS) • later became the garden path model (Frazier 1987) • Minimal attachment • Late closure
Session 5:Understanding the structure of syntax • Garden Path model: • Minimal attachment • Interpret sentences as having the simplest possible sturcture • Late closure • Interpret incoming word as part of the node under current construction • Peter found the book in library. • Peter found the book was the best book he ever read
Session 5:Understanding the structure of syntax • Constraint-based models of parsing • Processor uses multiple sources of information (syntactic, semantic, frequency-based) • Construction that is most strongly supported is most activated (and is usually the only to reach the level of consciousness) • Garden paths occur when the correct analysis receives little activation • („The old man the boat“)