Language Mind and Brain: The Unification Problem Colin Phillips Cognitive Neuroscience of Language Laboratory Department of Linguistics University of Maryland
Objective is to bridge gap between linguistic models, real- time models of mental processes, and brain-level models, i.e., focus is on the Unification Problem Cognitive Neuroscience of Language necessarily draws on disparate areas - not just looking at pictures of brains! Unification Problem
?? Unification Problem
No longer concerned with questions of whether linguistics is a natural science Language is clearly a remarkable specialization of human neurobiology (e.g., a sophisticated symbolic, recursive system, with fixed and parameterized aspects) What is it about human psychology & neurobiology that allows it to support the things that we know about language? In addressing this question, are we faced with problems or with mysteries?
Unification Problem...And if there are mismatches between theories at different levels, whose problem is this? Linguists? Psychologists? Neuroscientists?
Unification Problem On mismatches between cognitive and neural models “The more we learn about the brain, the greater the disanalogy becomes.” (A philosophy of (neuro-)science talk, October 2001)
Unification Problem On mismatches between cognitive and neural models “If language is unlike anything else in the biological world, …then too bad for biology!” (linguist, often accompanied by story about chemistry & physics)
Encoding & Computation Two main issues –How are linguistic representations encoded? –How are linguistic representations computed?
Sensory Maps Internal representations of the outside world. Cellular neuroscience has discovered a great deal in this area.
Notions of sensory maps may be applicable to human phonetic representations… …although attempts to find them have had little success to date. Vowel Space
Encoding of Symbols: Abstraction But most areas of linguistics (phonology, morphology, syntax, semantics) are concerned with symbolic, abstract representations,...which do not involve internal representations of dimensions of the outside world. …hence, the notion of sensory maps does not get us very far into language
Computation: Discrete Infinity In neuroscience there are many findings about long-term storage of object representations (e.g., edges, faces, grandmothers, toothbrushes, …). Such representations are always finite in number, which can be retrieved from long-term memory BUT, much of what interests us in linguistics is infinite If representations are drawn from an infinite set, they cannot be retrieved from long-term memory; they must be constructed on-line, as needed - this poses a different kind of challenge …
Overview of Talks
1. The Unification Problem
Overview of Talks 1. The Unification Problem 2. Building Syntactic Relations どの生徒に …
Overview of Talks 1. The Unification Problem 2. Building Syntactic Relations 3. Abstraction: Sounds to Symbols どの生徒に …
Overview of Talks 1. The Unification Problem 2. Building Syntactic Relations 3. Abstraction: Sounds to Symbols 4. Linguistics and Learning どの生徒に …
with help from... University of Maryland Shani Abada Sachiko Aoshima Daniel Garcia-Pedrosa Ana Gouvea Nina Kazanina Moti Lieberman Leticia Pablos David Poeppel Beth Rabbin Silke Urban Carol Whitney University of Delaware Evniki Edgar Bowen Hui Baris Kabak Tom Pellathy Dave Schneider Kaia Wong Alec Marantz, MIT Elron Yellin, MIT National Science Foundation James S. McDonnell Foundation Human Frontiers Science Program Japan Science & Technology Program Kanazawa Institute of Technology
Outline The Challenge Real-time Grammar Accurate Parsing Incremental Parsing Mapping onto the Brain: Electrophysiology Encoding Outlook
Outline The Challenge Real-time Grammar Accurate Parsing Incremental Parsing Mapping onto the Brain: Electrophysiology Encoding Outlook
Discrete Infinity Linguistic Creativity Ability to make infinite use of finite means The finite and infinite aspects of this system present rather different challenges for explicit linking hypotheses
Discrete Infinity Linguistic Creativity Ability to make infinite use of finite means Lexical entries, Argument Structure templates Widespread assumption: same representations accessed in comprehension, production, acceptability ratings, etc. Learner’s task is to construct a single lexical entry that covers all of these tasks
Discrete Infinity Linguistic Creativity Ability to make infinite use of finite means Sentence structures Structures must be assembled, cannot simply be retrieved from memory Widespread assumption: multiple different systems responsible for structure assembly in comprehension, production, acceptability, etc. Learner must master a number of different systems
Discrete Infinity Linguistic Creativity Ability to make infinite use of finite means Time-independent vs. Time-dependent systems
Standard View ? 217 x 32 = ? arithmetic
Standard View ? 217 x 32 = ? specialized algorithm arithmetic
Standard View ? 217 x 32 = ? specialized algorithm ? something deeper arithmetic
Standard View specialized algorithm speaking understanding grammatical knowledge, competence language
Standard View specialized algorithm speaking understanding grammatical knowledge, competence precise but ill-adapted to real-time operation language
Standard View specialized algorithm speaking understanding grammatical knowledge, competence well-adapted to real-time operation but maybe inaccurate language
If speaking and understanding involve different systems, there must be an additional store of knowledge that encodes what is shared between speaking and understanding.
As soon as we assume constructs such as ‘parsing strategies’, we are adopting task-specific mechanisms, and endorsing something like the standard architecture.
Standard View specialized algorithm speaking understanding grammatical knowledge, competence language
speaking, understanding, grammaticality Analysis-by-Synthesis Sentences are understood by internally generating a representation that matches the input No separate time-independent system of knowledge We know that humans have a real-time system for linguistic computation - issue is whether that’s all there is
But wait a minute... Wasn’t this all shown to be wrong long ago? (Fodor, Bever & Garrett 1974; Levelt 1974; Fillenbaum 1971; etc., etc.)? And a recent commentary: “In this desert of ignorance there have been attempts to resurrect earlier claims that the grammar and the parser are one and the same thing. … The enterprise is misconceived … probably incoherent.” (Smith, 1999)
Motivation for Standard Architecture How to constrain hypothesis generation Grammars are not incremental real-time systems Evidence for input/output-specific strategies Analysis-by-synthesis implies active generation, ahead of input Reputation of performance systems as fast but inaccurate Debunking of ‘Derivational Theory of Complexity’
Time-dependent system of computation makes it feasible to generate testable linking hypotheses Motivation for Alternative Architecture
Outline The Challenge Real-time Grammar Accurate Parsing Incremental Parsing Mapping onto the Brain: Electrophysiology Encoding Outlook
Linear Order and Constituency Linguistic Inquiry, 2003
Incremental Structure Building Evidence that sentence structures can only be assembled in a left-to-right derivation.
John said that he atethe entire pizza S NP VP S’ Comp V S NP VP VNP
John said that he atethe entire pizza S NP VP S’ Comp V S NP VP VNP Constituents
John said that he atethe entire pizza S NP VP S’ Comp V S NP VP VNP Constituents
John said that he atethe entire pizza S NP VP S’ Comp V S NP VP VNP Constituents
John said that he atethe entire pizza S NP VP S’ Comp V S NP VP VNP Constituents
Many tools used to diagnose groupings of words: –coordination –deletion –interpretation (coreference) –movement, focus, topicalization –etc. There are many cases where the tools converge on the same result There are also many cases where the tools yield conflicting results
Incremental Structure Building A (Phillips 2003)
Incremental Structure Building AB (Phillips 2003)
Incremental Structure Building A BC (Phillips 2003)
Incremental Structure Building A B CD (Phillips 2003)
Incremental Structure Building A B C DE (Phillips 2003)
Incremental Structure Building AB (Phillips 2003)
Incremental Structure Building AB constituent (Phillips 2003)
Incremental Structure Building A BC constituent is destroyed by addition of new material (Phillips 2003)
Incremental Structure Building A BC (Phillips 2003)
Incremental Structure Building A BC constituent (Phillips 2003)
Incremental Structure Building A B CD constituent is destroyed by addition of new material (Phillips 2003)
Incremental Structure Building the cat (Phillips 2003)
Incremental Structure Building the catsat (Phillips 2003)
Incremental Structure Building the cat saton (Phillips 2003)
Incremental Structure Building the cat sat on the rug (Phillips 2003)
Incremental Structure Building the cat saton (Phillips 2003)
Incremental Structure Building the cat sat on the rug (Phillips 2003)
Incremental Structure Building the cat sat on the rug [sat on] is a temporary constituent, which is destroyed as soon as the NP [the rug] is added. (Phillips 2003)
Incremental Structure Building Conflicting Constituency Tests Verb + Preposition sequences can undergo coordination… (1) The cat sat on and slept under the rug. …but cannot undergo pseudogapping (Baltin & Postal, 1996) (2) *The cat sat on the rug and the dog did the chair. (Phillips 2003)
Incremental Structure Building the cat saton (Phillips 2003)
Incremental Structure Building the cat satonsleptunder and (Phillips 2003)
Incremental Structure Building the cat satonsleptunder and coordination applies early, before the V+P constituent is destroyed. (Phillips 2003)
Incremental Structure Building the cat saton (Phillips 2003)
Incremental Structure Building the cat sat on the rug (Phillips 2003)
Incremental Structure Building the cat sat on the rug andthe dogdid (Phillips 2003)
Incremental Structure Building the cat sat on the rug andthe dogdid pseudogapping applies too late, after the V+P constituent is destroyed. (Phillips 2003)
Incremental Structure Building Constituency Problem Different diagnostics of constituency frequently yield conflicting results Incrementality Hypothesis (a) Syntactic processes see a ‘snapshot’ of a derivation - they target constituents that are present when the process applies (b) Conflicts reflect the fact that different processes have different linear properties start
Ellipsis blocks Scope/Binding Bill read all the books in a week (ambiguous: collective/distributive scope) …and Sue did in a month (unambiguous: collective scope only) Bill read as many books as Sue did in a week. (ambiguous) Bill read as many books in a week as Sue did in a month. (unambiguous)
Ellipsis blocks Scope/Binding John gave books to the children on Tuesday …and Mary did on Thursday John gave books to the children on each other’s birthdays *…and Mary did on each other’s first day of school
Japanese John
gave books to the children on each other’s birthdays VP V V IP John +fin I’ read all the books in a week VP V PP IP John +fin I’
gave books to the children on each other’s birthdays VP V V IP John +fin I’ read all the books in a week VP V PP IP John +fin I’
gave books to the children on each other’s birthdays VP V V IP John +fin I’ and VP IP Bill did I’
gave books to the children on each other’s birthdays VP V V IP John +fin I’ and VP IP Bill did I’
gave books to the children VP V IP John +fin I’
gave books to the children on each other’s birthdays VP V IP John +fin I’
gave books to the children on each other’s birthdays VP V IP John +fin I’ IP and VP IP Bill did I’
gave books to the children on each other’s birthdays VP V IP John +fin I’ IP and VP IP Bill did I’
gave books to the children on each other’s birthdays VP V IP John +fin I’ IP and VP IP Bill did I’ gave books to the children V VP
gave books to the children on each other’s birthdays VP V IP John +fin I’ IP and VP IP Bill did I’ gave books to the children V VP on each other’s first day of school VP
Movement & Binding a.John gave books to them on each other’s birthdays.
Movement & Binding a.John gave books to them on each other’s birthdays. gave books to them on each other’s birthdays VP V V (Pesetsky 1995)
Movement & Binding a.John gave books to them on each other’s birthdays. gave books to them on each other’s birthdays VP V V (Pesetsky 1995)
Movement & Binding b. …and [give books to them] he did ___ on each other’s birthdays (Pesetsky 1995)
give books VP V to them
give books VP V to them IP hedid
give books VP V to them IP hedid
give books to them VP V give books VP V to them IP he did I’ constituent movement
give books to them on each other’s birthdays VP V V give books VP V to them IP he did I’ constituent movement
give books to them on each other’s birthdays VP V V give books VP V to them IP he did I’ constituent movement binding under c-command
Interim Conclusion By building syntactic structures from left-to-right we can explain a number of otherwise mysterious constituency phenomena (see Phillips 1996, 2003 for more examples; see Richards 1999, 2002 for some applications to Japanese) We knew independently that humans have a left-to-right structure-building system (i.e. parser, producer) Possibility arises that the incremental left-to-right system is the only structure- building system that humans have Other arguments leading to related conclusions about grammar, in widely varying formalisms: Kempson et al. (2001), Steedman (2000), Kempen (1999), Milward (1992, 1994)
Outline The Challenge Real-time Grammar Accurate Parsing Incremental Parsing Mapping onto the Brain: Electrophysiology Encoding Outlook
Grammatical Accuracy It is not enough to show that syntactic structure-building looks like a real-time process If the real-time system is the only system, then it should also show the syntactic sophistication normally associated with the grammar - the parser cannot be ‘dumb’ Question: does the parser access only grammatically legal structural analyses?
Beyond Ambiguity Much of parsing literature focuses on issues of ambiguity, i.e. when 2 structures are grammatically possible, how to choose the right one? More basic question: grammatical search i.e. how do we figure out if a sequence of words has any grammatical analyses?
Example: Argument Structure Dative and Double-Object Constructions Alternator Verb: give The millionaire gave the painting to the museum. The millionaire gave the museum the painting. Non-alternator Verb: donate The millionaire donated the painting to the museum. *The millionaire donated the museum the painting. (Phillips, Edgar & Kabak, 2000)
Example: Argument Structure A Severe Garden-Path Sentence Alternator Verb: give The man gave the boy the dog bit a cookie
Example: Argument Structure A Severe Garden-Path Sentence Alternator Verb: give The man gave [the boy [the dog bit]] a cookie
Example: Argument Structure A Severe Garden-Path Sentence Alternator Verb: give The man gave [the boy [the dog bit]] a cookie availability of double-object parse leads to difficulty at embedded verb
Example: Argument Structure A Severe Garden-Path Sentence Alternator Verb: give The man gave [the boy [the dog bit]] a cookie Non-Alternator Verb: donate The man donated [the boy [the dog bit … availability of double-object parse leads to difficulty at embedded verb difficulty should arise earlier in the sentence
Results (partial) Relative to unambiguous control sentence, readers get into difficulty at V with alternator verbs, at NP2 with non-alternators. --> Argument structure constraint immediately active on-line Alternators (e.g. give)Non-Alternators (e.g. donate) start
Example: Movement Constraints
Grammatical Accuracy in Parsing Wh-Questions Englishmen cook wonderful dinners.
Grammatical Accuracy in Parsing Wh-Questions Englishmen cook wonderful dinners.
Grammatical Accuracy in Parsing Wh-Questions Englishmen cook what
Grammatical Accuracy in Parsing Wh-Questions Englishmen cook what
Grammatical Accuracy in Parsing Wh-Questions What do Englishmen cook
Grammatical Accuracy in Parsing Wh-Questions What do Englishmen cook gap
Grammatical Accuracy in Parsing Wh-Questions What do Englishmen cook gap
Grammatical Accuracy in Parsing Long-distance Wh-Questions Few people think that anybody realizes that Englishmen cook wonderful dinners
Grammatical Accuracy in Parsing Long-distance Wh-Questions Few people think that anybody realizes that Englishmen cook what
Grammatical Accuracy in Parsing Long-distance Wh-Questions What do few people think that anybody realizes that Englishmen cook gap
Grammatical Accuracy in Parsing The plan to remove the equipment ultimately destroyed the building.
Grammatical Accuracy in Parsing The plan to remove the equipment ultimately destroyed the building. Direct Object NP
Grammatical Accuracy in Parsing The plan to remove the equipment ultimately destroyed the building. Direct Object NP Main Clause
Grammatical Accuracy in Parsing The plan to remove the equipment ultimately destroyed the building. Direct Object NP Main Clause Subject NP Embedded Clause
Grammatical Accuracy in Parsing What did the plan to remove the equipment ultimately destroy
Grammatical Accuracy in Parsing What did the plan to remove the equipment ultimately destroy gap
Grammatical Accuracy in Parsing What did the plan to remove ultimately destroy the building
Grammatical Accuracy in Parsing What did the plan to remove gap ultimately destroy the building
Grammatical Accuracy in Parsing What did the plan to remove gap ultimately destroy the building Subject Island Constraint A wh-phrase cannot be moved out of a subject.
Question… Do people respect island constraints on movement immediately on-line? (tomorrow’s talk)
Outline The Challenge Real-time Grammar Accurate Parsing Incremental Parsing Mapping onto the Brain: Electrophysiology Encoding Outlook
Incrementality Question: is structure building immediate? Does it operate on a word-by-word level? …Even in a language where this may be hard?
Incremental Application of Binding Constraints in Japanese Sachiko Aoshima Colin Phillips Amy Weinberg
Structure-building in Japanese NP-wa NP-ni [NP-ga NP-o V] V Head-driven Parsing (e.g. Pritchett 1991, Mulders 2002) Structure-building is delayed until verbs are processed –explains how parsing is possible in Japanese –accounts for flexibility, limited garden-paths in Japanese Incremental Parsing Structure-building occurs immediately –accounts for native-speaker intuition of continuous comprehension –hard to demonstrate experimentally
John-ga … (Mazuka & Itoh 1995)
John-ga Mary-ni … (Mazuka & Itoh 1995)
John-ga Mary-ni ringo-o … (Mazuka & Itoh 1995)
John-ga Mary-ni ringo-o tabeta … (Mazuka & Itoh 1995)
John-ga Mary-ni ringo-o tabeta inu-o ageta (Mazuka & Itoh 1995)
Verb Surprise Effects Surprise effect appears at verb Can be explained by both head-driven and incremental theories (Schneider 1999, Mulders 2002) Better: evidence of structure-building that precedes the verb e.g. immediate application of grammatical constraints
English To which of his children did the man give a gift (Aoshima, Phillips & Weinberg 2002)
English To which of his children did the man give a gift Which of his children gave the man a gift? (Aoshima, Phillips & Weinberg 2002)
Japanese which of his children (DAT) the man (NOM) … which of his children (NOM) the man (DAT) … (Aoshima, Phillips & Weinberg 2002)
Japanese pronoun and its antecedent which of his children (DAT) the man (NOM) … his which of his children (NOM) the man (DAT) … *?*?*?*? which of his children (DAT)
which of his children (DAT) the man (NOM) … which of his children (NOM) the man (DAT) … Gender Mismatch the woman
Gender Mismatch which of his children (DAT) the man (NOM) … his which of his children (NOM) the man (DAT) … *?*?*?*? which of his children (DAT) the woman Gender mismatch the woman Gender mismatch irrelevant
Conditions a. Scrambled - Gender Mismatch Adverb / [his / which NP]-dat / Adverb / NP FEMALE -nom / Adverb / NP-acc / verb-Q / NP MALE -top / verb b. Scrambled - Gender Match Adverb / [his / which NP]-dat / Adverb / NP MALE -nom / Adverb / NP-acc / verb-Q / NP FEMALE -top / verb c. Non-scrambled - Gender Mismatch Adverb / [his / which NP]-nom / Adverb / NP FEMALE -dat / Adverb / NP-acc / verb-Q / NP MALE -top / verb d. Non-scrambled - Gender Match Adverb / [his / which NP]-nom / Adverb / NP MALE -dat / Adverb / NP-acc / verb-Q / NP MALE -top / verb.
Examples a. 台所で 彼の どの子供に 朝食後 叔母が 急いで お弁当を 渡 したか 父親は 覚えていた。 b. 台所で 彼の どの子供に 朝食後 叔父が 急いで お弁当を 渡 したか 叔母は 覚えていた。 c. 台所で 彼の どの子供が 朝食後 叔母に 急いで お弁当を 渡 したか 父親は 覚えていた。 d. 台所で 彼の どの子供が 朝食後 叔父に 急いで お弁当を 渡 したか 父親は 覚えていた。
Design & Procedure 2 X 2 factorial design 4 lists were created by distributing 24 items in a Latin Square design 56 filler sentences Comprehension questions: matching a subject with a predicate Self-paced reading task -Moving Window - 40 native speakers of Japanese
Self-paced reading task
Self-paced reading task どの子供に
Self-paced reading task 叔母は
Self-paced reading task 母親が
Self-paced reading task ケーキを
Self-paced reading task 焼いたと
Self-paced reading task 台所で
Self-paced reading task お手伝いさんに
Self-paced reading task 知らせましたか。
Results: Scrambled conditions Slowdown at mismatching NP is observed. his/her ± Match F 1 (1, 39) = 8.6, p<.01; F 2 (1,23)=7.4, p<.01
Results: Non-scrambled conditions Slowdown at mismatching NP only when NP is possible antecedent. his/her ± Match F S <1
Summary: Experiment 3 NP-nom Verb HIS-WH gap Binding constraint application takes place in advance of the verb. Wh-gap is posited in a simple clause. start
Experiment 3 (off-line): Grammatical judgment test which of his children (DAT) the man (NOM) … which of his children (NOM) the man (DAT) … *?*?*?*?
Experiment 3 (off-line): Stimuli a. Non-wh, Non-scrambled [His children]-nom Adv the man-dat b. Non-wh, Scrambled [His children]- dat Adv the man-nom c. Wh, Non-scrambled [Which of his children]-nom Adv the man-dat d. Wh, Scrambled [Which of his children]-dat Adv the man-nom
Experiment 3 (off-line): Design & Procedure 4 lists were created by distributing 32 items in a Latin Square design 16 items: same materials from online test, and 16 items: different from those in online test. 32 filler sentences Anaphoric relation judgment task 40 native speakers of Japanese, same individuals as the online test
Experiment 3 (off-line): Results Backwards anaphora are more allowed in scrambled conditions. It confirms that the binding facts underlying in the online test are correct. start
Grammatical Search and Reanalysis David Schneider Colin Phillips Journal of Memory & Language, 2001
Previous study showed incremental application of grammatical constraints, i.e. derivations operate on a word-by-word time-scale Next study: do real-time derivations show consistency, i.e does structure-building keep to a single derivation? how does is grammar searched to find possible analyses?
Grammatical Search the man knowsthe woman NP VP V NP S (Schneider & Phillips, 2001)
Grammatical Search the man knowsthe woman NP VP V S NP likes V (Schneider & Phillips, 2001)
Grammatical Search the man knows the woman NP VP V S NP likes V S (Schneider & Phillips, 2001)
Grammatical Search the man knows the woman NP VP V S NP likes V S It’s clear that this is the right conclusion, but it’s less clear how the system reaches this conclusion. (Schneider & Phillips, 2001)
Grammatical Search the man knowsthe woman NP VP V S NP likes V Option 1: combine with a local NP, ignoring existing status of the NP. (Schneider & Phillips, 2001)
Grammatical Search the man knowsthe woman NP VP V S NP likes V Option 1: combine with a local NP, ignoring existing status of the NP. (Schneider & Phillips, 2001)
Grammatical Search the man knowsthe woman NP VP V S NP likes V Option 2: search the structure for an NP subject that currently lacks a -role, i.e., focused search. (Schneider & Phillips, 2001)
Grammatical Search the man knowsthe woman NP VP V S NP likes V Option 2: search the structure for an NP subject that currently lacks a -role, i.e., focused search. (Schneider & Phillips, 2001)
Grammatical Search the man knowsthe woman NP VP V S NP likes V Option 2: search the structure for an NP subject that currently lacks a -role, i.e., focused search. This fails, so reanalysis is needed, … but only as a last resort operation.
the man knowsthe woman NP VP V S NP likes V Test Case If there is a higher NP, currently lacking a -role, a focused search will find it. (Schneider & Phillips, 2001)
the man knowsthe woman NP VP V S NP likes V S’ NP t who Test Case If there is a higher NP, currently lacking a -role, a focused search will find it. (Schneider & Phillips, 2001)
the man knowsthe woman NP VP V S NP likes V S’ NP t who S Test Case If there is a higher NP, currently lacking a -role, a focused search will find it. (Schneider & Phillips, 2001)
the man knowsthe woman NP VP V S NP Test Case If there is a higher NP, currently lacking a -role, a focused search will find it. S’ NP t who An unconstrained search will not be affected by the presence of the higher NP. likes V (Schneider & Phillips, 2001)
the man knows the woman NP VP V S NP Test Case If there is a higher NP, currently lacking a -role, a focused search will find it. S’ NP t who An unconstrained search will not be affected by the presence of the higher NP. likes V S (Schneider & Phillips, 2001)
the man knows the woman NP VP V S NP Test Case If there is a higher NP, currently lacking a -role, a focused search will find it. S’ NP t who An unconstrained search will not be affected by the presence of the higher NP. likes V S Probe Antecedents for reflexives. (Schneider & Phillips, 2001)
the man knows the woman NP VP V S NP Test Case If there is a higher NP, currently lacking a -role, a focused search will find it. S’ NP t who An unconstrained search will not be affected by the presence of the higher NP. likes V S Probe Antecedents for reflexives....the recipe herself...the recipe himself (Schneider & Phillips, 2001)
Test Case If there is a higher NP, currently lacking a -role, a focused search will find it. An unconstrained search will not be affected by the presence of the higher NP. Probe Antecedents for reflexives. the man knowsthe woman NP VP V S NP likes V S’ NP t who S...the recipe herself...the recipe himself (Schneider & Phillips, 2001)
Grammatical Search Relative to its unambiguous control, high attached reflexives pose no difficulty. (Schneider & Phillips, 2001)
Grammatical Search Relative to its unambiguous control, high attached reflexives pose no difficulty. …but low attached reflexives present great difficulty. (Schneider & Phillips, 2001)
Therefore... High attachment is chosen …despite well-known local- attachment biases. the man knowsthe woman NP VP V S NP likes V S’ NP t who S Grammatical search is focused, constrained by existing commitments (Schneider & Phillips, 2001)
Therefore... High attachment is chosen …despite well-known local- attachment biases. Grammatical search is focused, constrained by existing commitments knowsthe woman NP VP V S likes V the man NP This helps us to understand how grammatical search proceeds in simple cases.
Conclusions Local attachment is easy The local reanalysis is easy (cf. Sturt et al. 2000) So why is local attachment avoided? Reanalysis is a Last Resort (even if it’s easy)
Reversal of results…
NP-biased hear, warn, understand S-biased claim, believe, suspect
Outline The Challenge Real-time Grammar Accurate Parsing Incremental Parsing Mapping onto the Brain: Electrophysiology Encoding Outlook
Time Resolution Syntax: phrase-by-phrase time scale Reading-time studies: word-by-word time scale Brain recordings: millisecond time scale
Event-Related Potentials (ERPs) s1s2s3 John islaughing.
Evolving understanding of ERP components associated with language…
Semantically unexpected input She spread the warm bread with socks. (Kutas & Hillyard, 1980) She was stung by a fly. (Kutas, et al., 1984; Federmeier & Kutas, 1999) (Slide from Kaan (2001)
N400 Negative polarity peaking at around 400 ms central scalp distribution (Slide from Kaan (2001)
ERP Sentence Processing Developing understanding of N400 is informative Response to ‘violations’ N400 I drink my coffee with cream and sugar I drink my coffee with cream and socks Kutas & Hillyard (1980)
Vervet Monkeys Many predators: leopard, lion hyena, jackal, eagle, etc. etc. Distinct alarm calls for different predators
ERP Sentence Processing Developing understanding of N400 is informative Response to normal sentences N400 Fully Congruent Most new drugs are tested on white lab rats. Van Petten & Kutas (1991)
ERP Sentence Processing N400 N400 to semantic anomalies is a special case of a much more general phenomenon All words elicit N400-like response, timing and amplitude proportional to congruency, frequency, etc. More detailed understanding is contingent on more detailed models of semantic interpretation
Morpho-Syntactic violations Every Monday he mows the lawn. Every Monday he *mow the lawn. The plane brought us to paradise. The plane brought *we to paradise. (Coulson et al., 1998) (Slide from Kaan (2001)
he mows he *mow P600 (Slide from Kaan (2001)
he mows he *mow P600 Left Anterior Negativity (LAN) (Slide from Kaan (2001)
ERP Sentence Processing LAN, P600 Sie bereist das neuter Land neuter … Sie bereist den masculine Land neuter … she travels the land... Gunter et al. (2000)
Kaan et al. (2000) ERP Sentence Processing P600 Emily wondered who the performer in the concert had imitated for the audience’s amusement. Emily wondered whether the performer in the concert had imitated a pop star for the audience’s amusement. P600 reflects normal structure- building processes.
Electrophysiology of Wh-movement Colin Phillips, Nina Kazanina, Shani Abada, Daniel Garcia-Pedrosa [revision of work done at UDel in 2000]
Experiment Design Materials a. The actress wished that the producers knew that the witty host would tell the jokes during the party. b. The actress wished that the producers knew which jokes the witty host would tell __ during the party. c. The producers knew that the actress wished that the witty host would tell the jokes during the party. d. The producers knew which jokes the actress wished that the witty host would tell __ during the party.
a. The actress wished that the producers knew that the witty host would tell the jokes during the party. b. The actress wished that the producers knew which jokes the witty host would tell during the party. c. The producers knew that the actress wished that the witty host would tell the jokes during the party. d. The producers knew which jokes the actress wished that the witty host would tell during the party. Short wh-dependency Experiment Design Materials
a. The actress wished that the producers knew that the witty host would tell the jokes during the party. b. The actress wished that the producers knew which jokes the witty host would tell during the party. c. The producers knew that the actress wished that the witty host would tell the jokes during the party. d. The producers knew which jokes the actress wished that the witty host would tell during the party. Long wh-dependency Experiment Design Materials
+wh -wh Electrode PZ Short Conditionsn=20 Effect of wh-movement significant (p<.01) from ms onwards Verb
+wh -wh Electrode PZ Long Conditionsn=20 Effect of wh-movement significant (p<.01) from ms onwards Verb start
How fast is Structural Computation? Silke Urban Colin Phillips
Background Early Left Anterior Negativity (Angela Friederici, Anja Hahne, et al.)
Neville et al., 1991 The scientist criticized a proof of the theorem. The scientist criticized Max’s of proof the theorem.
500ms/word
Hahne & Friederici, 1999 Das Baby wurde gefüttert The baby was fed Das Baby wurde im gefüttert The baby was in-the fed Question: are the brain responses to violations automatic?
Hahne & Friederici, 1999 P600
Hahne & Friederici, 1999 ELAN
Very fast: ms Automatic Left anterior (= frontal) scalp distribution Elicited by a subclass of syntactic violations “ Phase 1 (100–300 ms) represents the time window in which the initial syntactic structure is formed on the basis of information about the word category.” (Friederici 2002)
Questions about ELAN How plausible is it that ELAN reflects syntactic structure building? –Speed: 150ms is faster than lexical access! –Generality: ELAN is not elicited by most violations; almost all studies on ELAN involve one construction (for each of German, English) –Localization…
Brodmann Areas
160 SQUID whole-head array pickup coil & SQUID assembly Magnetoencephalography (MEG)
(Friederici et al. 2000)
Two regions of interest (Friederici et al. 2000)
Anterior Temporal Lobe? Why is anterior temporal lobe so important in ELAN? How does it differ from Broca’s area (BA 44 etc.) that are implicated so often in other studies? Friederici: both responsible for ‘structure building’; BA44 also responsible for ‘syntactic working memory’; ‘the inferior portion of BA44 is selectively activated when syntactic processes are in focus.’ Anterior temporal lobe associated with –lexical information –activated in fMRI by comparisons of sentences with word lists
Alternative Interpretation ELAN reflects violation/suppression of automatic lexical prediction –accounts for localization to anterior temporal lobe –accounts for very early timing –might account for automaticity –accounts for very limited distribution
Neville et al., 1991 The scientist criticized a proof of the theorem. The scientist criticized Max’s of proof the theorem. NP Max’s N
Hahne & Friederici, 1999 Das Baby wurde gefüttert The baby was fed Das Baby wurde im gefüttert The baby was in-the fed NP the N in PP
Prediction If ELAN reflects violation of lexical prediction, rather than syntactic structure-building, then… –change lexical predictions –keep syntactic violation the same –should ‘turn off’ ELAN brain response
Neville et al., 1991 The scientist criticized a proof of the theorem. The scientist criticized Max’s of proof the theorem. NP Max’s N Possible to block the automatic prediction of an N following a possessor: ellipsis
Ellipsis Possessors may appear alone in ellipsis contexts: Although I like Mary’s theory, I don’t like John’s.
Experimental Conditions Although Erica kissed Mary’s mother, she did not kiss the daughter of the bride. Although Erica kissed Mary’s mother, she did not kiss Dana’s of the bride. Although the bridesmaid kissed Mary, she did not kiss the daughter of the bride. Although the bridesmaid kissed Mary, she did not kiss Dana’s of the bride.
Experimental Conditions Although Erica kissed Mary’s mother, she did not kiss the daughter of the bride. Although Erica kissed Mary’s mother, she did not kiss Dana’s of the bride. Although the bridesmaid kissed Mary, she did not kiss the daughter of the bride. Although the bridesmaid kissed Mary, she did not kiss Dana’s of the bride. ellipsis possible ellipsis impossible
Experimental Design 384 sentences per session –128 targets (drawn from 128 sets of 4 conditions) –64 items designed to elicit ‘agreement violation’ LAN –192 filler items, designed to hide violations and promote ellipsis Procedure –RSVP (Rapid Serial Visual Presentation), 500ms/word –Grammaticality judgment task Recording: 32-electrode montage 22 subjects (so far)
+
Although
Erica
kissed
Mary’s
mother,
she
did
not
kiss
Dana’s
of
the
bride.
??? good bad
Preliminary Results a. Although … Mary’s mother … Dana’s of … b. Although … Mary … Dana’s of … b a
Interim Conclusion Preliminary results lend support to our interpretation of the (E)LAN - the anterior negativity is reduced in an ellipsis context –structural violation is identical in both conditions –obligatory lexical prediction of N following possessor (e.g. Mary’s…) is absent in ellipsis context Structure-building may begin ~ ms after a word is presented
Outline The Challenge Real-time Grammar Accurate Parsing Incremental Parsing Mapping onto the Brain: Electrophysiology Encoding Outlook
The Binding Problem Discrete infinity Individual neurons (or groups of neurons) can store finite information about objects, words, etc. But sentences are infinite in number! Representing structure: can’t just activate all words e.g. THE + MAN + ATE + PIZZA Must create & discard structures quickly: 100s of msec
Temporal Binding the man ate pizza phase locked ~25ms, 40Hz
Evidence from Animals & Humans Direct recordings (cat)EEG recordings (human) (Singer 1999)(Tallon-Baudry & Bertrand 1999)
Limitations… No evidence yet of role in human syntax Limited capacity - ~7 bindings 1-level of hierarchy only Interesting hypothesis (Whitney & Weinberg 2002) –temporal binding is the neural representation used for the ‘syntactic workspace’ –additional neural encoding mechanism used for long-term representation and storage
Outline The Challenge Real-time Grammar Accurate Parsing Incremental Parsing Mapping onto the Brain: Electrophysiology Encoding Outlook
Overview –challenge for unification: real-time hypotheses Real-time Grammar –syntactic derivations look like real-time derivations Accurate Parsing –real-time derivations have the sophistication that is needed Incremental Parsing –real-time interpretation is time-locked to incoming words Mapping onto the Brain: Electrophysiology –extreme time-precision of EEG/MEG can be linked to detailed linguistic constructs Encoding –plausible models of neural encoding of structure are emerging Unification: Problem or Mystery…