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 Pattern 2: Word-meaning deafness – can repeat but not understand; can repeat words (80%) better than nonwords (7%); can understand written 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) Pure Word Deafness Pattern 1: ORF Repeats words (85%) better than nonwords (39%), but can understand familiar words Components can be used in various combinations depending upon the situation so there are three routes between hearing a spoken word and saying it: Auditory Analysis system: phonemic processing Auditory Input Lexicon: contains information about spoken words known to the listener (not meaning); recognizes spoken words as familiar by activation of the appropriate word units Semantic System: contains word meanings Speech Output Lexicon: provides spoken forms of words Phoneme response buffer: provides distinctive speech sounds Speech and nonspeech sounds can be separately impaired: Impairment of auditory analysis system in left hemisphere produced PWD; damage to analogous area dealing with nonverbal sounds is an “auditory sound agnosia”, or dealing with prosody is an “aprosodia”.

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

Visual word recognition is automatic….. red green blue green yellow red blue green blue red yellow green yellow red blue red

Visual Word Identification: Models I Serial Letter Model . Parallel Letter Model Visual Processing Letter Detection Word Detection Visual Processing Letter Detectors Word Detectors

Visual Word Identification: Models II Direct Word Model Interactive Activation Model Letter Detection Visual Processing Word Detection Visual Input Feature Analysis Letter Analysis Word Analysis

McClelland & Rumelhart’s Interactive Activation Model

CAT FOG COMB PINT MANTINESS FASS 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

Language Comprehension Parsing: analysis of syntactical (grammatical) structure of the sentence Analysis of literal meaning (semantics) Analysis of intended meaning (pragmatics)

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” Global and local levels 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 Incorrect object: towel on its own Disambiguating context: presenting an apple on a towel and another on a napkin Proportion of eye movements to the incorrect target as a function of sentence type and context. Garden path would predict that “on the towel” should be used to determine where the apple should be put. Disambiguation: Context has an apple on a towel and an apple on a napkin. “Put the apple on the towel in the box” Based on data in Spivey et al. (2002).

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 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 Data from van Gompel et al. (2001).

Inference Drawing Rumelhart and Ortony (1977) Logical inferences Mary heard the ice-cream truck coming She remembered the pocket money 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

Bock & Levelt (1984) ERRORS Intended meaning Semantic substitution (“tennis bat”), blending (“sky is shining”), word-exchange errors (“let the bag out of the cat”) Selection of word concepts, grammatical construction Ordering parts of sentence, adding inflection Morpheme exchange errors (“trunked two packs”), spoonerisms (“hissed my mystery lectures”) within same clause Phonological and prosodic elements worked out

Deep Dysgraphia Phonological 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 A M Lichtheim’s Model

Arcuate fasciculus

Syndrome Symptom Deficit Lesion Contemporary anologues of Lichtheim’s (1885) Aphasic Syndromes 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

Additional Aphasia Syndromes 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

Wernicke description of “Cookie Theft Picture” 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.

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

Spontaneous Prosody Good Poor Ross & Monnot (2007) Brain and Language

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