The Emerging Behavioral Phenotype in Down Syndrome and Williams syndrome:

Transcription

1 The Emerging Behavioral Phenotype in Down Syndrome and Williams syndrome: Links to Intervention Deborah J. Fidler, Ph.D. Colorado State University

2 Behavioral Phenotypes Behavioral Outcomes (Cognitive, Linguistic, Social, Emotional, Psychopathology, Motor) Genetic Disorder

3 Behavioral Phenotypes Syndrome Etiology Phenotype Down syndrome Trisomy 21 Language deficits, social strengths, visual > verbal processing, motor deficits, poor problem solving, task persistence Williams syndrome 7q deletion Hypersociability, fears and anxieties, verbal > visuo-spatial, expressive language strengths Prader-Willi syndrome Smith-Magenis syndrome 15q deletion (paternal) 17p deletion Mild MR, hyperphagia, hoarding, compulsive behavior, tantrums, skin picking, simultaneous>sequential processing Moderate-severe MR, self-injury, hyperactivity, stereotypies, sleep disturbances 5p- syndrome deletion 5p Severe MR, atypical catlike cry, hyperactivity, stereotypies, self-injury

4 Down Syndrome Behavioral Phenotype Relative strengths or MA appropriate: Some aspects of visual processing Some aspects of socialemotional functioning Receptive language Relative weaknesses: Auditory, verbal processing Expressive language Motor development and motor planning ASD caveat

5 Williams Syndrome Behavioral Phenotype Relative strengths or MA appropriate: Verbal/auditory processing Some aspects of socialemotional functioning Expressive language Relative weaknesses: Visuo-spatial processing Some aspects of socialemotional functioning Receptive language Fine Motor skills Anxieties, fears, inattention

6 Developmental Considerations Most of what we know about syndromespecific outcomes: Based on cross-sectional studies Based on older children, adolescents, and adults Less is known about how syndromespecific outcomes emerge and develop over time

7 Neuroconstructivist approach Karmiloff-Smith: Limitations of crosssectional approach Atypical development catalogue of intact and impaired modules Static, may be inappropriate for understanding dynamic process of development in genetic disorders

8 Neuroconstructivist Approach Karmiloff-Smith (1998): Brains of children with genetic disorders develop atypically throughout prenatal and postnatal development developmental timing, gene dosage, neuronal formation, neuronal density, biochemical efficiency, variations in transmitter types, dendritic arborization, synaptogenesis, and pruning throughout neurodevelopment

9 Neuroconstructivist Approach Tiny variations in initial state become magnified throughout development, leading to domain-specific differences in end states (Karmiloff-Smith, 1998)

10 Neuroconstructivist Approach Studying the emergence and development of behavioral phenotypes helps us focus not only on modularized end states, but on the pathways leading to end states

11 Opportunities for Intervention Earlier points on the pathway may offer a crucial window of opportunity for intervention, as tiny variations have not yet snowballed into impairments in whole domains of functioning

12 Early development in DS Longitudinal study toddlers (time 1) preschoolers (time 2) and early middle childhood (time 3) Sponsored by the National Institutes of Child Health and Human Development, PO1# HD35468 to Dr. Sally Rogers & Dr. Bruce Pennington; Collaborative Programs for Excellence in Autism Program Project

13 Early Development in DS Participants: 18 toddlers with Down syndrome 19 toddlers with mixed/non-specific developmental delays 24 MA-matched typically developing infants and toddlers Disability groups equated on CA (M = 33 mos) All groups equated on MA (M = 21 mos), gender

14 Early development in DS All children had normal vision or vision corrected to within normal range No hearing impairments beyond those commonly associated with Down syndrome No impaired hand use, all were mobile No between disability group differences on premature births, degree of early intervention services received Parents of typical children were significantly younger, but no Educational or SES differences

15 Can we detect variations in initial behavioral state in toddlers with Down syndrome?

16 DS Toddler Profile: MSEL Fidler, Hepburn & Rogers, Visual Reception Fine Motor Gross Motor Receptive Language Expressive Language

17 DS Toddler Profile: VABS Fidler, Hepburn & Rogers, Socialization Communication Daily Living Motor

18 Personality-Motivation in DS Fidler, 2006 Is there a personality style associated with Down syndrome? Wishart: Children with Down syndrome as sociable, but poor learners What do the empirical studies say? Poor task persistence, overreliance on social strategies

19 Preschoolers: Early Development in DS (Ruskin, Kasari, Mundy & Sigman, 1994) Poorer task persistence than MA matched typically developing children Shorter sequences of goal-directed behavior (Pitcairn & Wishart, 1994) Use of switching out strategies in order to divert attention to a less cognitively demanding activity Use of party tricks

20 Early Development in DS 5-12 yrs (Kasari & Freeman, 2002) Overuse of social behaviors during challenging tasks compared with MAmatched children with DD and typically developing

21 Early Development in DS (Fidler, 2006) Is this split between instrumental and social functioning already emerging in toddlers with Down syndrome?

22 Early Development in DS Candidate behaviors: Requesting (instrumental) Joint attention (social)

23 Nonverbal requesting Nonverbal requesting: instrumental, involves means-end thinking used with intent to regulate another s behavior in order to obtain object, initiate action Associated with problem solving, cause and effect thinking (Baron-Cohen, 1991; Bates, 1979; Camaioni, 1993; Gomez, 1990; Berko-Gleason, 1993)

24 Joint attention Joint attention: Declarative, deictic Serving to direct and focus an adult s attention on an object or an event Linked with social cognition, receptive language (Harris, Kasari, & Sigman, 1996; Tomasello, 1988; Tomasello, Mannie, & Kruger, 1986)

25 This study Do toddlers with Down syndrome show a split between instrumental (requesting) behaviors and social (joint attention) behaviors?

26 ESCS Early Social Communication Scales (Mundy, Hogan & Doehring, 1996) Joint attention Eye contact, alternating, pointing, showing Requests Eye contact, reaches, gives, points

27 Joint attention Fidler, Philofsky, Hepburn & Rogers, Down syndrome Other developmental disabilities Typical 5 0 Joint attention Equivalent frequency of joint attention behaviors in all groups, F (2, 55) =.89

28 Nonverbal Requests Fidler, Philofsky, Hepburn & Rogers, Requests Down syndrome Other developmental disabilities Typical Cohen s d =.96 F (2,55) = 4.43, p <.05 DS < Typical

29 Summary Toddlers with Down syndrome performed fewer instrumental (requesting) behaviors, but equivalent amounts of social (joint attention) behaviors

30 Are requesting skills in Down syndrome actually associated with problem solving skills?

31 Early development in DS Object retrieval 15 trials prize placed under a plexiglass box with one opening, child instructed to retrieve the prize through the opening Coded for retrieval strategy

32 Problem solving in Down syndrome Fidler, Philofsky, Hepburn & Rogers, Down syndrome Other developmental disabilities Typical 1 Retrieval Strategy scores Cohen s d = 1.18 Brown-Forsythe s F (2,48) = 8.60, p <.001 DS> DD

33 Problem solving and requesting Fidler, Philofsky, Hepburn & Rogers, mean retrieval strategy r (17) =.59, p <.05 r (15) =.58, p <.05 with overall MA partialled out "Initiates Request" Total

34 Summary Study 1 The personality-motivation style observed in older children with Down syndrome may be related to an early split between instrumental and social functioning

35 CSU pilot intervention Specific aims: strengthen early instrumental thinking strengthening behavior chaining Replace quitting out behaviors with more adaptive behaviors

36 Aim 1: Means-End Thinking Targeting early instrumental requesting behavior when a toddler with Down syndrome reaches the mental age of 9-13 months

37 Instrumental Requests

38 Aim 2: Strengthening of behavior chaining real life problem solving tasks involve more than one behavior in a sequence in order to solve the problem effectively It may be that strategizing difficulties are compounded by the cognitive load involved in chaining together a sequence of behaviors Construct easy-to-solve problem solving tasks that require more than one step and encouraging practice in assisted settings

39 Aim 2: Behavior Chains

40 Aim 3: Targeting Quitting out Common behavior problem: quitting out in the form of throwing toys Missing opportunities for growth, development

41 Aim 3: Reduce quitting out

42 Early Development in Williams syndrome Early emergence of behavioral phenotype in 2-6 year-old children with Williams syndrome Project sponsored by the March of Dimes (Hepburn, Fidler & Philofsky, )

43 Early Development in WS Fidler, Hepburn, Most, Philofsky & Rogers, 2007 Williams syndrome, n = 23; nonspecific developmental delays, n = 30 All participants in WS group had genetic diagnosis of Williams syndrome via FISH test Mixed group: 19 children with other genetic abnormalities (Down syndrome, Velo-cardiofacial syndrome, Cochayne syndrome, Smith- Magenis syndrome, partial deletion on chromosome 18, Angelman s syndrome, abnormalities on chromosome 15) 11 children with developmental delays of unknown etiology Groups matched on MSEL overall MA Williams syndrome M = 25.94, Mixed M = 28.8; verbal MA Williams syndrome M = 32.45, Mixed M = 27.48

44 Williams Syndrome MSEL profile Gross Motor Visual Receptive Fine Motor Expressive language Receptive language

45 Williams syndrome VABS profile Communication Daily Living Socialization Motor Skills

46 WS Behavioral Phenotype Hypersociability Excessive interest in others Lack of inhibition with regard to approaching others in social contexts (Jones et al., 2000)

47 Williams syndrome Could this be related to emotional responsivity in early development? Emotion battery Yummy-yucky (Repacholi & Gopnik,1997) Surprise boxes (Rogers et al) Empathy (knee and finger bangs; Sigman, Kasari, Kwon & Yirmiya,1992)

48 Facial Affect Fidler, Hepburn, Most, Philofsky & Rogers, Williams syndrome Other DD 10 0 Mimic Imitate

49 Vocal Affect Fidler, Hepburn, Most, Philofsky & Rogers, Mimic Imitate Williams syndrome Other DD

50 Correct gives Fidler, Hepburn, Most, Philofsky & Rogers, Williams syndrome Other DD 20 0 Gives

51 Implications Evidence for a split between primary and secondary intersubjectivity in young children with Williams syndrome? Hepburn, Philofsky, Fidler & Rogers, under review; Fidler, Hepburn, Most, Philofsky & Rogers, 2007 Emotion contagion may make children with Williams syndrome vulnerable Strong motivation for social relatedness coupled with poor social decision making

52 Implications for Intervention Opportunities to practice solving basic social problems (role play, doll play), social stories Circle of friends (actively teach who is a friend, acquaintance, stranger; rules for behavior)

53 General implications Early emergence of behavioral phenotypes: should we wait for areas of strength and weakness to become pronounced? Would an anticipatory guidance approach improve intervention planning?

54 General Implications Emerging strengths and weaknesses Capitalize on areas of potential strength as a way in to target potential areas of weakness alternate activities by skill domain, beginning and ending with domains of strength Imbed challenging tasks in tasks that involve areas of strength (e.g. Down syndrome: imbed motor tasks in play and other social contexts)

55 Etiology-specific findings can help interventionists and educators make informed decisions about appropriate strategies Can anticipate specific areas of potential difficulty and monitor more closely

56 Acknowledgements Sally Rogers, Ph.D. Susan Hepburn, Ph.D. Amy Philofsky, Ph.D., CCC-SLP Ashley Cole, BS Galit Mankin, MS Beth Wehner, Ph.D. Renetta Anderegg, MA Joanna Pepin, BS Liz Ricker, BS Leah Kryloff, BS Developmental Psychobiology Research Group

57 Thank you! Contact information:

58 Early Development in DS Fidler, Most, Booth-LaForce & Kelly, in press Down syndrome, n = 23; nonspecific developmental delays, n = 25 All participants in DS group had genetic diagnosis of trisomy 21 All children in comparison group had idiopathic (nonspecific) developmental delays All children were assessed at 12 months (Time 1) and 30 months (Time 2) Groups matched on Bayley mental scale raw scores at Time 1, t (46) =.005, p =.99, (Down syndrome M = 71.35, SD = 7.38; Mixed M = 71.36, SD = 10.58)

59 Cognitive development in DS Fidler, Most, Booth-LaForce & Kelly, in press 30 Bayley,12 mo,mental scale develpmtl age Bayley,30 mo,mental scale develpmtl age Mental Age (months) mixed dd Diagnostic Group ds

60 Social development in Down syndrome Fidler, Most, Booth-LaForce & Kelly, in press 80 Bayley,12 mo, Orientatn/engagemt pctile Bayley,30 mo, Orientatn/engagemt pctile mixed dd ds

61 Early Development in DS Children with DS: greater gains than comparison group in the area of social development but lesser gains than comparison group in the area of cognitive development