Language (and Decomposition)

Linguistics provides… a highly articulated “computational” (generative) theory of the mental representations of language that are used to “account for” –judgments of meaning and well-formedness –linguistics productivity: new sentences, new words –language acquisition: the ability of children to project beyond their linguistic experience

Analysis of Invariance vs Analysis of Variance Linguist: in a sentence like, “John saw Mary,” the subject is the one who sees and the object the one seen. Psychologist: In a picture-matching task, position of the name in a sentence, initial vs. final, was significantly correlated with behavior –i.e, explicitly contrast “John saw Mary” and “Mary saw John” and do an experiment

[Slides from Bob’s Analogy lecture] Another Example John loves Mary Loves JohnMary LoverBeloved Loves MaryJohn LoverBeloved Mary loves John

Yet Another Example John loves Mary and Bill hates Sally. Without Role Bindings John loves Mary and Bill hates Sally. With Role Bindings John loves Mary and Bill hates Sally. JohnLovesMary BillHatesSally Loves JohnMary Hates BillSally And Relational structure has been lost! Lover Beloved HaterHated Conjunct 1Conjunct 2

More Problems Representing Structure But role bindings alone don’t solve the problem of multiple instances of a predicate. Example –John bought the apples yesterday and the pears last week. –John bought the pears yesterday and the apples last week.

John bought the apples yesterday and the pears last week (incorrect): John bought the pears yesterday and the apples last week (incorrect) : John bought the apples yesterday and the pears last week (correct):

Representing Recursive Propositions in LTM A system with role bindings and instances of a predicate can represent recursively embedded propositions easily…

Recursive Embedding Example 1 Loves MaryJohn LoverBeloved Sam knows Mary loves John Knows KnowerKnown Sam

Recursive Embedding Example 2 Hug JohnMary HuggerHugged Mary kissing John caused John to hug Mary. Cause Effect Kiss MaryJohn KisserKissed Cause

Structured Representations: A Linguistic Example What does “rebuild” mean? (1) After the hurricane, John rebuilt his house. –Did John build the house to begin with? –Does(1) presuppose that anyone built the house before it was destroyed? –I'm going to pass on the help with the donation to help rebuild the Old Man of the Mountain.

The Old Man of the Mountain

Representation of “rebuild” Involves a number of parts: –Building activity –A caused “creation” as the result of building –The presupposition: end state of building existed before The linguist assumes that the complex structural representation of these parts would underlie any use or comprehension of the word

Tension: The Status of Linguistic Representations In linguistics, a “syntactic” representation mediates between sound (or letters, the hand movements of sign, etc.) and meaning (interface with other cognitive functions) The linguist operates under the assumption that language comprehension and production (as well as the generation of judgments of well-formedness) requires in every instance the creation of syntactic representations

The tradition in cognitive psychology is to suppose that the linguistic representations are “abstract” and either not necessarily or rarely constructed when people speak and understand language on a daily basis -- people can use strategies, statistics, analogy, etc. to map directly between sound and meaning.

Example: Morphological Decomposition amiability Linguistic representation: n adj rootadj n amiable ity “able” predicts category, meaning and potentiation of -ity

Pinker in “Words and Rules” 3 Theories of “Irregular” Morphology full decomposition: “gave” = GIVE + PST => [ give [ ø ] ] dual route (=Pinker’s mediation between linguists and psychologists) “gave” = the past tense of “give” “walked” = WALK + PST => [ walk [ ed ] ] single route: “gave” = the past tense of “give” “walked” = the past tense of “walk”

From the linguist’s perspective, only the full decomposition model makes any sense “gave” behaves as a complex form with respect to syntactic and morphological distribution: –“the walkeding” = “the gav(e)ing” –He walked/He didn’t walk/*He didn’t walked –He gave/He didn’t give/*He didn’t gaved

“Evidence” for Dual Route View Lack of surface frequency effects for regular inflection: –RT to “walked” correlates with stem frequency of “walk” rather than surface frequency of “walked” –While RT to “taught” correlates with surface frequency of “taught” rather than stem frequency of “teach”

Lack of priming for irregulars –“walked” primes “walk” but –“taught” doesn’t prime “teach” –(“darkly” and “darkness” prime “dark” but “darkly” doesn’t prime “darkness”)

On surface frequency… Consider the informativeness of the past tense ending with respect to the stem: –For most regulars, -ed does not predict stem (except for very high frequency regulars, and for those one gets surface frequency effects) –For irregulars, form of past tense predicts past tense and vice versa

On priming… “stripes” primes “lion” (through “tiger”) Clearly, “taught” should semantically prime “teach” Lack of behavioral priming between “taught” and “teach” demands an explanation in terms of a theory of the task (e.g., Lexical Decision)

False equation of “memorized” with “frequency” with “irregularity” with “whole vs. composed” “Irregularity” within language is governed by principles of structural locality Frequency always matters, both for the minimal constituents of language and for composed constituents, regardless of “regularity”

CNS 2008 Poster