Language II

October 15, 2009

Why is Language Important?

• Represents unique form of abstraction in human species

• Language influences perception and memory

• Relevant to the form and manner of information storage

• Relevance to thinking and problem-solving is unquestioned

• Chief means of human communication

Key Terminology• Phonology: (the way sounds function in the language)

basic unit = phoneme– single speech sound– English has about 45; 9 make up half our words– dimensions: voiced (“a”); unvoiced (“s”); fricatives

(“sh”), plosives (“t”); place of articulation (palate v. lips)

• Morphology: (study of the internal structure of words) basic unit = morpheme– smallest unit of meaning (words, parts of words, etc.)– free (e.g., “old”, “the”) vs. bound (e.g., “er”, “ist”)– over 100,000 words formed by morpheme

combinations• Semantics: (study of meaning)

– denotation vs. connotation – e.g., “heart”– words as economic labels; link between language

and concepts• Syntax: (study of rules that govern combination of

morphemes in phrases and sentences; interdependency)– prescriptive vs. descriptive grammar– “Daddy, what did you bring that book that I don’t

want to be read to out of up for”?

Language Comprehension

Auditory Word Recognition: Basic Processes

• Bottom-up: processing of individual phonemic features

• Top-down: conceptual processing– phonemic restoration effect:

• probably affects response bias, not sensitivity

“the *eel was on the axle” - hear “wheel”“the *eel was on the shoe” - hear “heel”“the *eel was on the orange” - hear “peel”

Theories of Auditory Word Recognition I• Motor Theory of Speech Perception (Liberman et

al., 1967)– during listening, listeners mimic articulatory

movements of speaker and depend on this for recognition

– Supported by PET studies showing motor activation during speech perception

– noninvariance is a problem, as is infant data• Cohort Theory (Marslen-Wilson & Tyler, 1980)

– activation of word cohort as speech signal arrives– some activated words eliminated on basis of context;

continues until “recognition point” is achieved– assumes that lexical, syntactic, and semantic

information interact to analyze speech signal; context effects are probably late• e.g., “The police indicated that excessive SP---

was a factor in the fatal accident.”

Auditory Word Recognition: Theories II

• TRACE Model (McClelland, 1991)– three units of levels: features,

phonemes, words– between-level connections excitatory– within-levels inhibitory– excitation in the network produces

pattern, or “trace” of activation– recognized word is that which is

highest among candidate words

A Simple Feature-Detection Network

Auditory Word Recognition: Theories III

• Cognitive Neuropsychological Models– derive from studies of how word recognition

fails after brain injury– make use of “box models” of cognitive

processing popular in mainstream cognitive psychology

– basic structural features:• domain-specific systems• lexicons

Model of Processes involved in Analysis of Spoken Words

Normally, all routes are available; damage to system reveals fractionated performance which serves to “isolate” each route to a greater or lesser degree

Route 1: accesses full representation of word, including meaning and spoken form

Route 2: same as route 1 without meaning

Route 3: involves phoneme-spoken form conversion (e.g., for repetition)

Pattern 1: ORFRepeats words (85%) better than nonwords (39%), but can understand familiar words

Pattern 2: Word-meaning deafness – can repeat but not understand; can repeat words (80%) better than nonwords (7%); can understand written words

Pure Word Deafness

Stages in Lexical Processing (Single Word Recognition)

• Contact of the analyzed waveform with the lexicon– Spectrographic (LAFS)– Motor theory– Phonemic theories

• Activation of specific lexical entries • Selection of appropriate lexical entry

from set of activated candidates• Access to the full information from the

lexical entry

Reading (Visual Word Comprehension)

• Similar processes likely, but entry into the system is a visual (graphemic), not an acoustic (phonemic) representation

• Transformation from graphemes to phonemes is critical

• Two routes to reading– Grapheme-phoneme conversion– Lexical (whole word) reading

How Reading is Studied

• Eye movement recordings• Reading aloud• RSVP (rapid serial visual

presentation)• Subject-controlled presentation• Word-identification techniques

– lexical decision– naming

Eye-Movement Research• Emphasizes a “word-recognition” vs. “meaning construction”

approach to reading• Asymmetric perceptual span (3-4 letters to the left of fixation

and 15 letters to the right)• Parafoveal preview allows for skipping words• Fixations may be affected by context and meaning

– predictable words receive less fixation– “garden path” sentences:

“The young man turned his back on the rock concert stage and looked across the resort lake. Tomorrow was the annual one-day fishing contest and fishermen would invade the place. Some of the best bass guitarists would come to this spot”

– derivation of meaning occurs early (parafoveally? instantaneously?)

Fixation data from a normal (PP) and a dyslexic (Dave) reader

Numbers immediately below the dots are the sequence of eye movements, and the lower numbers are fixation times

Visual Word Identification

• Rapid (200ms)• Automatic (e.g., Stroop effect)• Basic effects:

– word-letter effect: letters identified better if in words than if alone (e.g., TAKE v. _ _ K _)

– word-superiority effect: letters identified better when in real word (e.g., TAKE v. PAKE)

– These effects imply that “word environment” influences recognition

red green blue

green yellow red

blue green blue

red yellow green

yellow red blue red

Visual word recognition is automatic…..

Visual Word Identification: Models I

• Serial Letter Model

.

.• Parallel Letter Model

Visual

ProcessingLetter Detection Word Detection

Visual

Processing

Letter Detectors Word Detectors

Visual Word Identification: Models II

• Direct Word Model

• Interactive Activation Model

Visual Processing

Letter Detection

Word Detection

Visual

Input

Feature Analysis

Letter Analysis

Word Analysis

McClelland & Rumelhart’s Interactive Activation Model

Cognitive Neuropsychological Model of Processes

involved in Reading – the “Dual Route

Cascaded Model” (Coltheart, et al 2001)

Example from book:

CAT FOG COMB PINT MANTINESS

FASS

Route 1 (Grapheme–Phoneme Conversion)

• Converting spelling (graphemes) into sound (phonemes)

• Marshall and Newcombe (1973)– Surface dyslexia – poor reading of irregular

words; strong reliance on Route 1• McCarthy and Warrington (1984)

– KT read 100% of nonwords accurately, and 81% of regular words, but was successful with only 41% of irregular words

– Over 70% of the errors that KT made with irregular words were due to regularisation

• Significant variability in performance, suggesting that this is not a clear dissociation

Phonological Awareness

Route 2 (Lexicon Plus Semantic System)

• Event sequence– Representations of familiar words are stored

in an orthographic input lexicon; activation leads to…

– Meaning is activated by the semantic system and..

– Sound pattern is generated in the phonological output lexicon

• Beauvois and Dérouesné (1979)– Phonological dyslexia – impaired Route 1;

use Route 2; 100% real words; 10% nonwords

Route 3 (Lexicon Only)

• Like Route 2 but the semantic system is bypassed – printed words are pronounced but not understood

• Funnell (1983)– Phonological dyslexia with poor ability to

make semantic judgments about words• Coslett (1991)

– Reasonably good at reading irregular words, but had no understanding of them

Deep Dyslexia• Characteristics

– Particular problems in reading unfamiliar words

– An inability to read nonwords– Semantic reading errors (e.g., “ship” read as

“boat”)• Damage to the grapheme–phoneme

conversion and semantic systems• Patterson, Vargha-Khadem, and Polkey

(1989)– Studied left hemispheric removal, producing

all of these symtpoms; argued that reading is taking place in right hemisphere

• Laine et al. (2000) used MEG– Activation mainly in the left hemisphere

Parsing• Four major possibilities:

– Syntactic analysis generally precedes (and influences) semantic analysis

– Semantic analysis usually occurs prior to syntactic analysis

– Syntactic and semantic analysis occur at the same time, in parallel

– Syntax and semantics are very closely associated, and have a hand-in-glove relationship

Grammar/Syntax• Syntax – word order and combination critical

to meaning:– “He showed her the boys pants.”– “He showed her boys the pants.”

• An infinite number of sentences is possible in any language

• Sentences are nevertheless systematic and organised

• Chomsky (1957, 1959)– Rules to take account of the productivity and the

regularity of language– A grammar should be able to generate all the

permissible sentences in a given language

Syntactic Ambiguity• “They are flying planes”

– The grammatical structure is ambiguous• Global and local levels• Making use of prosodic cues

– Stress and intonation (illustrate with above example)• Allbritton, McKoon, and Ratcliff (1996)

– Doubts about the use of prosodic cues• Snedeker and Trueswell (2003)

– Listeners’ interpretation of ambiguous sentences was influenced by prosodic cues even before the start of the ambiguous phrase

Garden-Path Model• Frazier and Rayner (1982)

– Only one syntactical structure is initially considered for any sentence

– Meaning is not involved in the selection of the initial syntactical structure

– The simplest syntactical structure is chosen, making use of two general principles: minimal attachment and late closure

– According to the principle of minimal attachment, the grammatical structure producing the fewest nodes is preferred

– The principle of late closure is that new words encountered in a sentence are attached to the current phrase or clause if grammatically permissible

Evidence for the Garden-Path Model

“Put the apple on the towel in the box”

Based on data in Spivey et al. (2002).

Incorrect object: towel on its own

Disambiguating context: presenting an apple on a towel and another on a napkin

Constraint-based Theory• MacDonald et al. (1994) – all relevant information/constraints

are available – various possibilities influence comprehension to the extent they are activated– Grammatical knowledge constrains possible sentence interpretations– The various forms of information associated with any given word are

typically not independent of each other– A word may be less ambiguous in some ways than in others (e.g.,

ambiguous for tense but not for grammatical category)– The various interpretations permissible according to grammatical rules

generally differ considerably in frequency and probability on the basis of past experience

– As the woman edited the magazine amused all the reporters.– As the woman sailed the magazine amused all the reporters.

Unrestricted Race Model (combines features of GP and CB theories)

• Van Gompel, Pickering, and Traxler (2000) – combines aspects of GP and UR models– All sources of information are used to identify a

syntactic structure, as is assumed by constraint-based models

– All other possible syntactic structures are ignored unless the favoured syntactic structure is disconfirmed by subsequent information

– If the initially chosen syntactic structure has to be discarded, there is an extensive process of re-analysis before a different syntactic structure is chosen

Evidence for the Unrestricted Race Model

• Data from van Gompel et al. (2001).

Ambig: The burglar stabbed only the guy with the dagger during the night.

Verb-phrase: The burglar stabbed only the dog with the dagger during the night.

Noun-phrase: The burglar stabbed only the dog with the collar during the night.

GP: 2>3

UR: 2=3>1

Inference Drawing• Rumelhart and Ortony (1977)

1) Mary heard the ice-cream truck coming2) She remembered the pocket money3) She rushed into the house

WHAT’S HAPPENING HERE?

• Logical inferences– Depend on the meaning of the words

• Bridging inferences– Establish coherence between the current part of the

text and the preceding text• Elaborative inferences

– Serve to embellish or add details to the text

Drawing Inferences in Language Comprehension• “She took out an apple and ate it.”• Anaphora: “Bob told Bill about his

serious illness”– Bridging inference: “his” refers to

“Bob”• depends on distance between Bob and

“his” (probably not)• depends on “Bob” as topic of discourse

• Three models:– constructivist: full mental model formed– minimalist: only limited, constrained, inferences are

formed (automatic vs. strategic distinction)– search-after-meaning: meaning constructed ‘after

the fact’ in accordance to goals

• The types of inferences normally drawn, together with the predictions from the S-A-M and minimalist perspectives. Adapted from Graesser et al. (1994).

Speech/Language Production I

• Common Features of Models– extensive pre-planning– distinct stages of processing– general (intended meaning)-to-

specific (utterance) organization– most models use of speech errors as

data

Semantic substitution (“tennis bat”), blending (“sky is shining”), word-exchange errors (“let the bag out of the cat”)

Morpheme exchange errors (“trunked two packs”), spoonerisms (“hissed my mystery lectures”) within same clause

Bock & Levelt (1984)

ERRORS

Selection of word concepts, grammatical construction

Ordering parts of sentence, adding inflection

Phonological and prosodic elements worked out

Intended meaning

Phonological

Dysgraphia

Deep

Dysgraphia

Language Disorders

Types of Disorders

• Aphasia: acquired disorder of language due to brain damage

• Dysarthria: disorder of motor apparatus of speech

• Developmental language disturbances• Associated disorders

– Alexia– Apraxia– Agraphia

Major Historical Landmarks

• Broca (1861): Leborgne: loss of speech fluency with good comprehension

• Wernicke (1874): Patient with fluent speech but poor comprehension

• Lichtheim (1885): classic description of aphasic syndromes

C

M A

Lichtheim’s Model

Arcuate fasciculus

Syndrome Symptom Deficit Lesion

Broca’s Aphasia speech production;

sparse, halting speech, missing function words,

bound morphemes

Impaired speech planning and production

Posterior aspects of 3rd frontal convolution

Wernicke’s Aphasia

Auditory comprehension, fluent speech, paraphasia, poor repetion and naming

Impaired representation of sound structure of words

Posterior half of the first temporal gyrus

Pure motor speech disorder

Disturbance of articulation, apraxia of

speech, dysarthria, aphemia

Disturbance of articulation Outflow from motor cortex

Pure Word Deafness

Disturbance of spoken word comprehension,

repetition also impaired

Failure to access spoken words

Input tracks from auditory cortex to Wernicke’s area

Transcortical Motor Aphasia

Disturbed spontaneous speech similar to BA; relatively preserved

repetition, comprehension

Disconnection between conceptual word/sentence representations and motor

speech production

Deep white matter tracks connecting BA to parietal

lobe

Transcortical Sensory Aphasia

Disturbance in single word comprehension with

relatively intact repetition

Disturbed activation of word meanings despite normal recognition of

auditorily presented words

White matter tracks connecting parietal and

temporal lobe

Conduction Aphasia

Disturbance of repetition and spontaneous speech,

phonemic paraphasia

Disconnetion between sound patterns and speech production

mechanisms

Arcuate fasciculus; connection between BA

and WA

Contemporary anologues of Lichtheim’s (1885) Aphasic Syndromes

Additional Aphasia Syndromes

Syndrome Symptom Deficit Lesion

Anomic Aphasia single-word production,

marked for common nouns; repetition and comprehension intact

Impaired storage or access to lexical entries

Inferior parietal lobe or connections within

perisylvian language areas

Global Aphasia Performance in all language functions

Disruption of all/most language components

Multiple perisylvian language components

Isolation of the language zone

Spontaneous speech, comprehension, some

preservation of repetition; echolalia

common

Disconnection between concepts and both

representations of word sounds and speech

production

Cortex outside perisylvian association

cortex

Broca’s Aphasia

• Telegraphic, effortful speech• Agrammatism• Some degree of comprehension

deficit• Writing and reading deficits• Repetition abnormal – drops

function words• Buccofacial apraxia, right

hemiparesis

M.E. Cinderella ... poor ... um 'dopted her ... scrubbed floor, um, tidy ... poor, um ... 'dopted ... Si-sisters and mother ... ball. Ball, prince um, shoe ...

Examiner. Keep going.M.E. Scrubbed and uh washed and un...tidy, uh, sisters and

mother, prince, no, prince, yes. Cinderella hooked prince. (Laughs.) Um, um, shoes, um, twelve o'clock ball,

finished.Examiner. So what happened in the end?M.E. Married.Examiner. How does he find her?M.E. Um, Prince, um, happen to, um ... Prince, and Cinderalla

meet, um met um met.Examiner. What happened at the ball? They didn't get married at the

ball.M.E. No, um, no ... I don't know. Shoe, um found shoe ...

Wernicke’s Aphasia

• Fluent, nonsensical speech• Impaired comprehension• Grammar better preserved than in

BA• Reading impairment often present• May be aware or unaware of deficit• Finger agnosia, acalculia, alexia

without agraphia

C.B. Uh, well this is the ... the /dødøü/ of this. This and this and this and this. These things going in there like that. This is /sen/ things here. This one here, these two things here. And the other one here, back in this one, this one /gø/ look at this one.Examiner. Yeah, what's happening there?C.B. I can't tell you what that is, but I know what it is, but I don't now where it is. But I don't know what's under. I know it's you couldn't say it's ... I couldn't say what it is. I couldn't say what that is. This shu-- that should be right in here. That's very bad in there. Anyway, this one here, and that, and that's it. This is the getting in here and that's the getting around here, and that, and that's it. This is getting in here and that's the getting around here, this one and one with this one. And this one, and that's it, isn't it? I don't know what else you'd want.

Wernicke description of “Cookie Theft Picture”

Conduction Aphasia

• Fluent language• Naming and repetition impaired• May be able to correct speech off-

line• Hesitations and word-finding

pauses• May have good reading skills

Global Aphasia

• Deficits in repetition, naming, fluency and comprehension

• Gradations of severity exist• May communicate prosodically• Involve (typically) large lesions• Outcome poorest; anomic

Transcortical Aphasias

Transcortical Motor• Good repetition• Impairment in producing

spontaneous speech• Good comprehension• Poor naming

Transcortical Sensory• Good repetition• Fluent speech• Impaired comprehension• Poor naming• Semantic associations poor

Fundamental Lessons

• Language processors are localized• Different language symptoms can

be due to an underlying deficit in a single language processor

• Language processors are regionally associated with different parts of the brain in proximity to sensory or motor functions

What Language Disorders Reveal about Underlying Processes

• Pure Word Deafness: selective processing of speech sounds implies a specific speech-relevant phonological processor

• Transcortical Sensory Aphasia: repetition is spared relative to comprehension; selective loss of word meaning; some cases suggest disproportionate loss of one or more categories

What Language Disorders Reveal about Underlying Processes

• Aphasic errors in word production: reveal complex nature of lexical access– Phonological vs. semantic errors: independent vs.

interactive relationship?– Grammatical class: nouns vs. verbs (category

specificity)• Broca’s aphasia: syntax comprehension and production

– Central syntactic deficit; loss of grammatic knowledge

– Problems in “closed-class” vocabulary (preposition, tense markers)

– Limited capacity account– Mapping account (inability to map from parsing to

thematic roles)• Jargon Aphasia: can construct gramatically “better”

sentences than agrammatics, but can’t find words, producing neologisms; reinforces distinction between content and grammatical struture

Prosody

• Linguistic vs. nonlinguistic prosody• Evidence for hemispheric

differences• Clinical syndromes

– Disturbances of comprehension• Auditory affective agnosia• Phonagnosia

– Disturbances of prosodic output• Aprosodias

Ross & Monnot (2007) Brain and Language

Spontaneous Prosody

Good

Poor

Ross & Monnot (2007) Brain and Language

Semantic System

• System for storing meaning• Meaning stored separately from form• Models of representation in semantics

– Feature-based models (see categorization)– Nondecompositional meaning (lexicons)

• Modality-specific (fractionated) semantic deficits– Modality-specific deficts (e.g., optic aphasia)

Category-specific: e.g. living things, fruits

Two Example Models of Semantic Organization

One Semantic System

Multiple Semantic Systems