Dr. Jóhanna Einarsdóttir

Transcription

1 Stuttering in Preschool Children: Identification and Measurement Dr. Jóhanna Einarsdóttir University of Iceland

2 The thesis was based on following papers 1. Einarsdóttir, J., & Ingham, R.J. (2005). Have disfluency type measures contributed to the understanding and treatment of developmental stuttering? American Journal of Speech-Language Pathology, 14, Einarsdóttir, J., & Ingham, R.J. (2008). The effect of the Stuttering Measurement and Assessment Training (SMAAT-child) on preschool teachers ability to identify stuttering. Journal of Fluency Disorders, 33, Einarsdóttir, J., & Ingham.R.J. (2009). Does language influence the accuracy of judgments of stuttering in children? Journal of Speech, Language and Hearing Research, Einarsdóttir, J., & Ingham, R.J. (In press). Accuracy of parent identification of stuttering occurrence. International Journal of Language and Communication Disorders.

3 For consideration To investigate the nature and treatment of a disorder requires accurate identification of the behaviour or symptoms that define that disorder the identification of stuttering is based on perceptual judgments that speech fluency is recurrently abnormal.

4 The aim of this presentation What methods have we been using for measuring stuttering in preschool children What is the character of abnormal speech fluency based on video exemplars How did we develop a standardized system for training judges to identify and measure stuttering in three to five year old children How can we proceed in the future towards identification and measurement of stuttering in young children

5 Why is accurate identification and measurement of stuttering important? Because clinicians need to be able to distinguish between children who stutter (CWS) and children who do not stutter (CWNS), and between stuttering and normal speech. Because there are no physiological markers that can be used to identify stuttering other than perceptually abnormal speech Because there is no successful acoustic neural network program available that will reliably and accurately identify stuttering

6 How has stuttering been measured in preschool children? Two different methods are now used to measure stuttering in preschool children 1. Counts of different types of disfluencies usually stutterlike disfluencies (SLDs) or SLDs plus other disfluencies (ODs) 2. Counts of speech events that are perceived as moments of stuttering usually converted to the percentage of syllables that are moments of stuttering (%SS)

7 Stutter-like disfluencies (SLDs) and Other disfluencies (ODs) The use of disfluency categories, such as syllable repetitions or prolongations, have been used in the past to identify and measure stuttering in young children. It was critically reviewed in this paper Einarsdóttir, J., & Ingham, R.J. (2005). Have disfluency type measures contributed to the understanding and treatment of developmental stuttering? American Journal of Speech-Language Pathology, 14,

8 These studies reported data on Total disfluencies or SLD and OD Johnson et al. (1959) 2-8 yr. (words) Yairi & Lewis (1984) 2-3 yr. (syllables) Hubbard & Yairi (1988) 2-4 yr. (syllables) Ambrose & Yairi (1999) 2-5 yr. (syllables) Pellowsky & Conture (2002) 3-4 yr. (words) Zackheim & Conture (2003) 3-5 yr. (words) Logan (2003) 3-4 yr. (syllables)

9 Disfluency-type measurement Total disfluencies The studies showed that there was a difference between the two groups of children (CWS and CWNS) by measuring their total disfluencies per 100 words or syllables The difference between CWS and CWNS ranged from 6.3 to 16.6 (higher for CWS) SLDs-ODs

10 SLDs ODs Part-word repetitions Single-syllable word repetitions Prolongation, Dysrhythmic phonation (tense pause) Comparable categories Interjections Phrase repetitions Revisions Incomplete phrases Comparable categories

11 SLDs-ODs Stuttering like disfluencies (SLDs). Data shown from seven studies CWS CWNS Other Disfluencies (ODs). Data shown from seven studies CWS CWNS

12 Summary and Conclusions The difference between the CWS and CWNS is mainly within their SLDs rather than their ODs But SLDs may include stuttered and nonstuttered disfluencies so this is an ambiguous measure

13 Disfluency categories vary so much and there is no standardized system for coding disfluencies No standardized method for training judges for labelling the different disfluencies-types The number or the proportion of different types of disfluencies in the speech of a CWS or CWNS has not been shown to have any prognostic value

14 Reliability problems??? Three studies have investigated the validity and reliability of using disfluency type measures (Onslow, Gardner, Bryant, Stuckings and Knight, 1992; Cordes, 2000 and Bothe, 2008). All these studies reported lack of reliability by using disfluency type measurement for counting stuttering in young children and adults.

15 Counting stuttering (%SS) Based on the perceptual threshold measure of stuttering (Martin & Haroldson, 1981) Events that exceed judges perceptual threshold for normal speech are judged as stuttered But there are interjudge and interclinic reliability problems with this measure

16 Reliability problems? Young (1975) Curlee (1981) Martin & Haroldson (1981) Kully and Boberg (1988) Ingham and Cordes (1992) Cordes and Ingham (1995)

17 Test -count stutterings

18 Time interval procedure A method for improving the reliability of stuttering measurement Intervals are judged as Stuttered and Nonstuttered (usually 5-s intervals) Agreed Stuttered and Nonstuttered intervals can be identified and compared between and within judges Agreed Intervals can be used for training purposes

19 Test counting stuttered intervals

20 Time interval procedure 1) 20 children were videotaped (Each tape recording was min) 2) The tapes were transcribed 1-min samples selected where the child was speaking in sentences 3) Seven 1-min samples were selected from each child 4) Three SLPs identified at least one unambiguous stuttering on each tape The SLPs selected 9 children, 6 boys and 3 girls, who displayed different severities and characteristics of stuttered speech

21 5) Each recording was divided into 5-s intervals of speech separated by a 5-s silent interval for judgment 6) The 756 intervals (84 intervals for each child) were randomized, to form Random 1 and Random 2 7) Ten Icelandic SLPs judged all speech intervals as either Stuttered or Nonstuttered on two occasions, Random 1 and Random 2 Ten US-SLPs also judged all the speech intervals for comparation 8) From each child two 1-min samples were selected for the SMAAT-training program (SMAAT=Stuttering Measurement and Assessment Training)

22 Data analyses The data were analyzed interval by interval Intrajudge agreement was calculated for each SLP The number of intervals judged as stuttered was calculated for each child and for each SLP Interjudge agreement was the percentages of intervals that at least 80% of the judges agreed were either Stuttered or Nonstuttered

23 The number of Agreed/Disagreed intervals on Occasion 1 and 2 Agreed Intervals (80% agreement: the same interval judgment made for at least 16 out of 20 opportunities) Disagreed intervals were all other intervals (all below 80% agreement) Child Stuttered Nonstuttered Disagreed Total

24 TOTAL NUMBER OF INTERVALS JUDGED STUTTERED The number of Stuttered judgments assigned by each SLP 450 ICE SLPs ICE SLPs ICE 1 ICE 2

25 Investigating identification of Stuttering across languages To determine whether stuttering judgment accuracy is influenced by familiarity with the stuttering speaker s language To test whether there is a core set of exemplars of stuttering that exist regardless of whether they are identified by Icelandic or non-icelandic speaking judges Einarsdóttir & Ingham (2009).

26 Method 10 US-SLPs were selected who had no knowledge of the Icelandic language Comparable group to the Icelandic SLPs (gender, age, working experience) The US-SLPs had to pass a criterion test to show that they could identify stuttering in own language The same judgments procedure was used with both groups

27 Results for intrajudge agreement ICE-SLPs. Their mean intrajudge agreement was 89.6%: range =76.2% % US-SLPs. Their mean intrajudge agreement was 89.3%: range =72.6% % No significant differences were found between the ICE-SLPs and US-SLPs intrajudge agreement percentage scores (t(18) = 0.18, p=.857)

28 TOTAL NUMBER OF INTERVALS JUDGED STUTTERED The number of Stuttered judgments assigned by each SLP ICE SLPs US SLPs ICE 1 US 1 ICE 2 US 2

29 Mean number of intervals judged stuttered The mean number of Stuttered judgments assigned to each child ICE 1 ICE 2 US 1 US 2

30 Comparision between the ICE and the US SLPs on Agreed Intervals Occasion 1 Occasion 2 Occasion 1 and 2 ICE US ICE US ICE US ST DIS N-ST Agr percent 80.0% 85.4% 83.3% 85.3% 80.2% 81.7%

31 Number of intervals per child that ICE-SLPs and US-SLPs agreed were Stuttered (80% or greater) Child AGREED STUTTERED INTERVALS ICE- SLPs US-SLPs Identically Agreed Totals

32 Samples of Agreed Stuttered intervals

33 Number of intervals per child that ICE-SLPs and US-SLPs agreed were Nonstuttered (80% or greater) Child AGREED NONSTUTTERED INTERVAlS ICE- SLPs US-SLPs Identically Agreed Totals

34 Samples of Agreed Nonstuttered Intervals

35 Number of intervals per child that ICE-SLPs and US- SLPs agreed to be disagreed Child DISAGREED INTERVAlS ICE- SLPs US-SLPs Same Intv. Disagreed Totals

36 Samples of Disagreed Intervals

37 Summary and Conclusions The present findings show that experienced SLPs are generally able to recognize similar exemplars of stuttering and nonstuttering in young CWS who speak a foreign language The ICE-SLPs and the US-SLPs agreed on their judgments for approximately 90% of the same intervals There was no significant main effect between overall mean of stuttering judgments per child across the two judgment groups. (3-factor repeated measures ANOVA [F(1,18) =.15, p =.703]) There was a non significant Group effect for the Agreed Stuttered interval data (2-factor repeated measures ANOVA [F(1, 24) = 0.21, p =.65])

38 Summary and conclusion The number of intervals judged stuttered varied considerably within each group of SLPs The interval judgements for ICE-SLPs ranged from 161 intervals judged stuttered to 399 The interval judgements for US-SLPs ranged from 169 intervals judged stuttered to 331 The findings highlight the need for standardized training for clinicians to identify stuttering

39 Standardized training system There is a need for standardized training for clinicians to be able to identify stuttering reliably and accurately in children The standardized training for young children was based on a system known as the Stuttering Measurement Assessment and Training (SMAAT). It was developed by using video samples of 3-5 year old children and relied on Time-intervalprocedures

40 SMAAT-child training Assessment task Training task The judge presses the right mouse button on a computer each time he or she believes the child stuttered The assessment task - no feedback Training task provides feedback If the judge makes an incorrect judgment the monitor screen freezes and then replays the incorrectly judged 5 sec interval highlighting that it was either an Agreed Stuttered or Agreed Nonstuttered interval The effect of the training program was evaluated with 20 preschool teachers

41 The effect of the SMAAT-child training - preschool teachers 20 preschool teachers assessed the videotapes on two occasions (Approx. two hours of assessment ) The teachers were randomly allocated into two groups an experimental and a control group The experimental group was trained with the SMAAT-child training program

42 Percent stuttered interval judgment accuracy The result Occasion 1 Occasion 2 Experimental Control

43 Summary and Conclusions Even before training the preschool teachers were shown to be capable of identifying stuttering with satisfactory accuracy But the interval-based training program still significantly improved judgment accuracy within the experimental group of preschool teachers There was a significant difference between group [F(1,18) = 13.20; p <0.001] There was a significant difference between occasions [F(1,92) = 25.79; p <0.0001] There was a significant interaction effect [F(1,92) = 9.27; <0.001]. Cohen d was large (d=1.5) By using the time interval procedure it was possible to develop an effective training program for identifying agreed stuttered intervals

44 Final Conclusions 1. Investigating any disorder requires that it be accurately identified 2. The use of disfluency typologies such as syllable repetitions or prolongations for identify and measure stuttering in young children cannot form the basis of a valid stuttering measurement method

45 Final Conclusions 3. By using time interval as measurement method, inter-and intrajudge agreement is high for Agreed Stuttered and Nonstuttered intervals 4. A group of preschool teachers and parents showed high accuracy by identifying correctly Agreed Stuttered and Agreed Nonstuttered intervals

46 Final Conclusions 5. The SMAAT-child training program effectively improved the accuracy with which preschool teachers identified stuttered intervals 6. Knowing that preschool teachers and parents can be accurate and reliable judges of stuttering or trained to be - means they can provide trustworthy data and can add to the understanding and treatment of developmental stuttering

47 Final Conclusions 7. There were great similarities between the judgments ICE-SLPs and US-SLPs on the samples of Icelandic preschool children although interesting disagreements were found 8. The high number of language independent stuttering samples tends to support claims that stuttering is a speech-motor disorder rather than language disorder

48 Future implications of findings A standardized method of identifying stuttering occurrences makes it possible to conduct fundamental epidemiological research on developmental stuttering of young children makes it possible to evaluate the effects of treatment and adds to our understanding of unassisted recovery

49 Future implications of findings The use of intervals that are consistently judged as Stuttered or Nonstuttered by ICE-SLPs and by US- SLPs (583 out of 756) can make a major contribution to the common understanding of stuttering include a core set of language-independent stuttering exemplars may be used to develop a training material that can be used across languages for identifying stuttering accurately

50 The SMAAT-Child training

51 Acknowledgements Special thanks are to Roger J Ingham This work was supported by University Eimskipafélag Fund, Graduate Research Fund of The Icelandic Centre for Research, Educational Grant of Landsbanki Íslands, Reykjavik Educational Fund, Oddur Ólafsson Grant, Málbjörg (The Icelandic Stuttering Association)