Autism Spectrum Disorders: Core Symptoms and their Development

Rhea Paul, Ph.D., CCC-SLPSouthern Connecticut State University

Yale Child Study CenterFeb. 11-15, 2008

rhea.paul@yale.edu

Triad of symptoms

Severe, qualitative impairment in social interaction

Qualitative impairment in communication

Restrictive, repetitive or stereotyped behaviors interests or activities

Social Interaction Gaze

Attentional patterns Eye contact

Joint Attention Imitation Emotion and attachment Reciprocity Play Peer Relations

Eye Contact/Using Gaze to Share

Eye Contact

Toddler with autism Typically-developing toddler

2-year-olds with autism and typical development viewing video of child playing

Gaze Patterns

Gaze development in ASD Newborns show preference for faces

prefer eyes by 2 mo. Can detect direction of other’s gaze by 4

mo. Children with ASD fail to develop

these patterns Problems in gaze persist throughout

the life span, even in HFA Are resistant to intervention

Joint Attention (Intersubjectivity) Dyadic: infant looks at adult Triadic: Begins w/ gaze following (6 mo.) Progresses to following point (8-10 mo.) Then to initiation w/ smiling and pointing at

objects of interest (12 mo.) Lays basis for conversation Very low frequency in ASD, appears later

than TD Can increase with age

Joint Attention Video examples:

JA DD JA Autism Imitate JA

Imitation Emerges in infancy Basis of learning Fades in typical development Role of mirror neurons Less spontaneous imitation and less

in elicitation settings for children with ASD

Imitation In normal developmenthttp://www.youtube.com/watch?v=-rWKSTtM6Ys In ASDHaddia example

Emotion and attachment Social referencing Comfort seeking Sharing emotion with

gaze Children with ASD

Do show attachment Have difficulty recognizing

emotions: may be related to difficulties in face perception

Less likely to coordinate expression of emotion (smile) with gaze

Difficulties in empathy (hurt examiner experiment)

Decreased social referencing (robot experiment)

Sharing emotions

Sharing emotions

Reciprocity Turn-taking emerges before language Back-and-forth nature of social

interaction Deficits in reciprocity can be seen

in both verbal and nonverbal individuals

Reciprocity: Preverbal

Reciprocity: Verbal

PlayNormal development: 0-8 mo. All schemes to all objects 8-12 mo. Functional play 12-18 mo. Autosymbolic play 18-24 mo. Single scheme symbolic play 24-36 mo. Multischeme symbolic 3-5 Pretend, role play 5-12 games with rules

Play in ASD Favor exploratory, means-ends,

construction, stereotypical play over pretend play

Even symbolic play can be repetitive and stereotypic

May prefer solitary play May have difficulty w/ flexibility in

games w/ rules

Play

http://www.youtube.com/watch?v=zAu6ehEGMQc&feature=related

Peer Relations TD children move from family-centered to

peer-centered social relations Children with ASD may

Prefer to remain solitary Be ineffective in approaching and engaging peers

Make fewer approaches to peers Respond less often to peer bids

Those w/ HFA may prefer adults to peers Expand interest in peers during adolescence Become depressed over loneliness and lack of

friendships

Communication: Definitions

Communication Message Sender Receiver

Language Rule-governed Conventional Symbolic Culturally Determined Communication

Speech Vocal expression Sounds of language

Language Domains

Communication is a primary deficit in autism Of the triad of symptoms, communication is

directly involved in two Communication deficits are a primary

means of identifying and diagnosing autism Communication in autism involves both

delaydelay and deviancedeviance. Primary area of difficulty is in pragmaticspragmatics

BUT deficits in other areas can also be seen; sometimes are similar to those of children with specific language impairments (SLI).

Communication in Typical Development

Communication Development: Capacities at birth Vision best at face-to-face range Infants show preferences for

Faces over other visual stimuli Speech over other sounds Female voices over other voices Own mother’s voice over other female voices Motherese speech-style over adult directed style

Can discriminate phonemes of native and non-native languages

Typical Communication Development: Preverbal & Early Language

Perlocutionary Stage: 0-8 mo. 0-4 mo.: Preference for faces,

speech 4-8 mo.: Development of

vocal communication 6-10 mo.:

Emergence of preference for ambient language patterns

Emergence of speech-like sounds

Communication Development: Preverbal Form

Production 0-2 mo.: Vegetative

sounds 2-4: Cooing &

laughing 4-8 mo.: vocal play 6-10 mo.: canonical

babble 8-18 mo.: jargon

babble with prosodic contours of ambient language

Perception 0-6 mo.: general speech general speech

processing abilitiesprocessing abilities that are biologically determined and “generic;” can apply to any linguistic input (Eimas et al., 1971.)

7-12 mo.: Change in preferences from those that would apply to anyany language toward ones those closely tuned to the sound patterns of the environmentenvironment

Perlocutionary Communication

Illocutionary Stage: 8-12 mo.Use

• Development of intentional communication expressed through • Gestures, e.g., pointing• Vocalization• Gaze

• Small range of functions expressed• Proto-imperative• Proto-declarative

• 2.5 communicative acts/minute• Emergence of prosodic

patterns of ambient language.

Illocutionary Stage: Content and Form Expressive vocabulary starts slowly

12 mo: 1-3 words 15 mo.: 10 words 18 mo. 50-100 words; first word combinations

First 50 words include proper and common nouns, adjectives, verbs, social terms

Receptive vocabulary is larger: 50 words at 15 mo.

Most words have CV shape, one syllable Sounds used are same as those found in

babble: /b/, /p/ /m/, /n/, /d/, /h/, /w/.

Illocutionary Stage: Gestures used to express intents: Contact Point

Illocutionary Stage: Gestures used to express intents: Reach

Illocutionary Stage: Gestures used to express intents: Distal Point

Illocutionary Stage: Gestures used to express intents: Show

Illocutionary Stage: Other Conventional Gestures

Illocutionary Communication

Locutionary Communication: 12-18 mo.

First words spoken

First words comprehended outside of routines

Rapid increase in spoken vocabulary:

–15 mo: 3 words

–18 mo.: 50-100 words (+/-100)

–24 mo.: 300 words (+/-150)

Word combinations begin when vocabulary=50

Same intents expressed with gestures, vocalization now expressed with words

New discourse-related intentions expressed

•request information•answer•acknowledge

5-7 communicative acts/minute on average

Locutionary Development: Content

Early two-word utterances express a small range of meanings Agent, action, object combinations Possession Location Attributes Meanings related to

object permanence

Locutionary Communication

Communication Development: 18-24 mo.

Repertoire of speech sounds increase CVC and multisyllabic words increase; many still single syllable Average child is 50% intelligible Average expressive vocabulary size at 18 mo. Is 100 words

(+/- 100)• Multiword utterances increase in frequency; vocabulary grows• Understanding of sentences is not far ahead of production• Pragmatic developments:

New discourse-related communicative functions: Discourse management

Turns: increasing awareness of conversational obligation

Topics: 1-2 turns/topic Register variation

18-24 mo. Communication

Limitations in Communication is ASD: Prelinguistic Level

Delayed onset of speech (Stone et al., 1994) Atypical preverbal vocalizations (Sheinkopf et al., 2000) Depressed rate of preverbal communication (Wetherby,

Prizant & Hutchinson, 1998) Restricted range of communicative behaviours, limited

primarily to regulatory functions (Mundy & Stella, 2000) Low responsiveness to speech (Osterling & Dawson,

1994) Delayed and deviant use of gestures (Dawson et al.,

1998; Stone, et al., 1997) Dearth of pretend and imaginative play (Stone et al.,

1994) Laci of imitation orally, vocally, and verbally (Volkmar

et al., 1997)

TD: Comment

ASD: Comment

Developing Language

Communication Development: 24-36 mo. Form and Content Average expressive vocabulary size at 24 mo. Is

300 words (+/-150); word classes include Object & action words Kinship terms Spatial terms Question words Color, shape words

Grammatical morphemes, verb phrase marking emerges; some overgeneralization

Grammatical forms for sentences such as questions, negatives are emerging

Sentence length is 3-5 words Intelligibility increases from 50% to 70%

Communication Development: 48-60 mo.: Form & Content Vocabulary at school entry=6000 words Basic grammatical forms mastered

expressively and receptively; few grammatical errors are heard Overgeneralization may persist

Average 4 year is 100% intelligible Speech errors may persist, but speech

can be understood Residual errors in /s/, /l/, and /r are last

to resolve

Background: Pragmatics of Language

Pragmatic domains: Communicative functions Discourse management Register variation Presupposition Prosody

Communication Development: 48-60 mo.: UseCommunicative functions• Increase in range of functions• New genre: narration• Increase in decontextualized talkDiscourse management• Requires less support from

adults; still needs some• Longer turns; more turns/topic

Communication Development: 48-60 mo.: Use Register variation

• New polite forms: • permission requests, permission

directives, some indirect requests• 4-7: hints

• Ability to use ‘motherese’

Preschool Conversation

Early Verbal Communication in ASD

Pronoun reversals Idiosyncratic word use Use of immediate and delayed

echolalia (communication strategy) Perseverative conversation Atypical voice and prosodic features

Echolalia

http://www.youtube.com/watch?v=sniGZoVB0R4&feature=related

Conversation in ASD

Communication Development in Later Childhood and Adolescence Syntax/Semantics

Increases in oral and written forms Increases in figurative, nonliteral

language Pragmatics

Discourse Genres Narration Persuasion/negotiation Exposition Ambiguity/sarcasm

Register variation Slang Figurative language

Communication in Youth

Impairments in Higher Level Language Skills in ASD

Reduced topic management skills appropriate topic termination Responding to cues to change topic Commenting contingently; say something

relevant Reduced presuppositional skills due to “theory of

mind” (ToM) deficits Poor ability to share topics infer other’s informational state

Obsessive, circumscribed interests Sparse conversation OR overly

talkative about special interests Gaze and prosodic deficits persist

Discourse Management Example

Presupposition Example

Prosody Example

Circumscribed Interest Example

Repetitive behaviors http://www.youtu

be.com/watch?v=-6blmKiPe9c&feature=related

http://www.youtube.com/watch?v=MB9UDDLJfKM&feature=related

Controversial Treatments

Promise to cure the core symptoms of ASD Definition of the core deficits often lacks

solid empirical evidence (e.g., metabolic problems, exposures, ‘visual processing’)

Offer vague benefit (e.g., improve focus) Lack of empirical evidence

Reliance on uncontrolled studies, single-case testimonials

Claim that ‘they cannot be studied ‘ Often claim persecution form the scientific

establishment Staying open-minded

Gluten- Free & Cassien-Free Diet (GFCF) “Leaky gut” -> peptides crossing blood-

brain barrier -> disrupted neurotransmitter breakdown -> increase of opiotoids -> activity-autism.

“Leaky gut” could be caused by: yeast overgrowth, gastrointestinal disease due to immunization, etc.

No evidence for these causal relationships

Systematic study of GFCF diet initiated at University of Rochester

Ethyl Mercury (Thimerosal) Exposure

1. Danish “Natural Experiment”• 1970 – 1992 petrussis vaccine contained

Thimerosal• 1992-1997: same vaccine w/o Thimerosal• 1997: different petrussis vaccine w/o Thimerosal

2. Danish Psychiatric Register Data: contrary to prediction, no difference in rates of autism was found between groups who received Thimeraosal and those who did not

Chelation Therapy

Hypothesized toxic effects of mercury exposure, mercury accumulates in internal organs (hair trace analysis)

Chelation: introduction into the blood stream agents that bond with specific metals in the body

Purely hypothetical connection between mercury poisoning and autism

No empirical evidence supporting the claim, no reports of curing autism or improving symptoms following chelation

Possible side-effects of chelation: washes out valuable minerals, very costly diagnostic process

Two children have died following chelation.

Supplements

Assumption that developmental disabilities may be caused by innate biochemical errors

E.g., B6+magnesium supplements

Lack of well-controlled, long-term follow up studies

Possible side effects: high dose of B6: possible neuromotor side effects in adults, magnesium: potentially toxic metal in high doses

Secretin Pancreatic hormone assisting digestion “Cure” of autism (Horvath et al., 1998)

after single injection of the hormone Controlled studies: secretin has the same

effect as placebo (Carey et al., 2002; Chez et al., 2000; Owley et al., 1999)

Positive effect on children with autism and diarrhea, but no reduction in aberrant behaviors; no effect on those w/o diarrhea (Kern et al., 2002)