cognitive morphology laura westmaas november 24, 2009

COGNITIVE MORPHOLOGY

COGNITIVE MORPHOLOGY

Laura WestmaasLaura Westmaas

November 24, 2009November 24, 2009

OutlineOutline

•Cognitive Morphology

•Theories of morphology

•Methods for studying morphology

•Inflectional morphology

•Derivational moprhology

•Theoretical implications

•Cognitive Morphology

•Theories of morphology

•Methods for studying morphology

•Inflectional morphology

•Derivational moprhology

•Theoretical implications

Psycholinguistics

• Definition

• Goals

Cognitive Morphology

• Getting into the headspace of psycholinguistic literature

• Formal definitions/conceptualizations of morphology

• Goals of theory/research/models

What is the morpheme?

•Traditional definition “smallest meaningful bearing unit in a language” (Whitley, 2001)

•Classes of morphemes

•Inflectional

•Derivational

Experimental methodology

• behavioural

• priming

• lexical decision tasks

• Electrophysiological, neuroimaging

• Bilinguals and special populations (children, aphasics, dyslexics)

• Rationale of methodology

Morphological Theory

Whole word (e.g., Feldman & Fowler, 1987)

Dual route (e.g., Marslen-Wilson, Tyler, Waksler & Older, 1994)

Obligatory morphemic decomposition (e.g., Taft & Forster, 1975; Taft, 2004; Rastle et al.)

Connectionist (E.g Plaut & Gonnerman, 2000; Seidenberg & Gonnerman, 2000, Rueckl et al, 1997))

Whole Word Approach

HAPPY

HAPPY

HAPPINESS

HAPPINESS

Stimuli

Lexicon

Stimuli

Lexicon

Example from Marslen-Wilson, et al, 1994

Dual route theory

• Words and Rules theory (Pinker & Ullman, 2002)

• Grammatical rules + stem in lexicon

• Irregulars and monomorphemic words in lexicon

QuickTime™ and a decompressor

are needed to see this picture.

Obligatory Decomposition

HAPPY -NESS

HAPPINESS

Stimuli

Lexicon

Connectionist Models

QuickTime™ and a decompressor

are needed to see this picture.

The triangle model

QuickTime™ and a decompressor

are needed to see this picture.

Inflectional morphology

• The case of past tense

• (Masked) priming paradigm

• Lexical decision task

• Behavioural predictions/ findings

• Interpretations

• Frequency by regularity interaction

• Some recent research

+BAKED

+

BAKELexical decision: Y/N

+TOOK

+

TAKELexical decision: Y/N

Classic findings

• Response times (ms) are faster for regular than irregular words

• Dual route would say this is because try to apply rule, blocked then access lexicon

• Connectionist would say that this is a by-product of the degree of semantic, orthographic and phonological overlap between the prime and target word

• Also note that there is a frequency by regularity interaction.

QuickTime™ and a decompressor

are needed to see this picture.

Interpretation of frequency by regularity interaction

• Dual route: highly frequent irregulars get stored directly in lexicon, direct access just like regulars

• Connectionist: overlap from prime lowers the threshold of activation, mapping between sound, meaning and orthography not as clear

• -greater reliance on semantics (v.s. phonology)

• -picture task to see if activation via meaning rather than form would wipe out differences between irregular and regular verbs

• Dual route prediction: it shouldn’t, need to activate stem than past tense

• Connectionist prediction: should get rid of effect of regularity

Woolams, Joanisse & Patterson (2009, JML)

QuickTime™ and a decompressor

are needed to see this picture.

Derivational morphology

• Questions of interest

• Predictions

• Rastle findings

• Feldman findings

• Thesis

Question

•What happens when a reader encounters a multi-morphemic word?

Predictions?

• Obligatory decomposition:

• If it looks like a morpheme, take it apart!

• VERSUS

• Connectionist:

• Graded- take it apart, sometimes

• - but not just about the morphemes.

morpheme

not a morpheme

Semantic TransparencyRastle et al (2004)

• Semantically transparent

• e.g. harden-hard

• Semantically opaque

• e.g. corner-corn

• Form

• e.g. brothel-broth

Connectionist

• Graded Effects

PAINTER DRESSER CORNER BROTHEL

Transparent *** Opaque Form

Semantically related Not related

Examples from Rastle et al, 2004,

The Case of Opaque Words

Has supported decomposition, under a certain set of experimental conditions

characteristics of study seem to matter:

– Prime duration; non-word stimuli, orthographic neighbours, word length, word frequency, etc.

Masked Priming

• Logic:

– if morphemes are used to decompose words, should see priming effects between a multi-morphemic word and its stem compared ton unrelated baseline

+CORNER

CHAIR

+

CORN

Lexical decision: Y/N

Masked priming

Main findings (Eg. Rastle et al, 2004)

HARDEN-HARD

- CORNER-CORN

- BROTHEL-BROTH no priming

Taken as evidence for obligatory decomposition during early stages of visual word recognition.

priming

My thesis, currently in progress

• ERP investigation of differences in the N400 component between pseudo-suffixed and suffixed words by using a color-morpheme boundary manipulation.

• Predictions:

• Dual route theory: no difference between suffixed and pseudo-suffixed

• Connectionist: differences between suffixed and pseudo-suffixed words; congruency by word type interaction.

Experimental ParadigmPrinzmetal, Treiman, & Rho (1986) Carreiras, Vergara, & Barber (2005)

Explore the effects of mis/match of morpheme boundaries

Word in 2 colours and in/congruent

– E.g. CONGRUENT WALKED

• INCONGRUENT WALKED

Procedure

4 Word Lists

• congruent congruent incongruent incongruent

• dresser dresser dresser dresser

• Transparent, opaque, form + intermediate cases (eg. dresser)

• Only one list seen by each participant.

Conclusions

• Current state of the art

• Current directions of the field

• what psycholinguistic research can tell us about morphology

• need for inter-disciplinary research

• Questions/Comments?

• Thanks!