1. Verónica Martínez, Aránzazu Antón, Manuela Miranda, Vanesa Pérez,
IASCL-XIIth INTERNATIONAL CONGRESS FOR THE STUDY OF CHILD LANGUAGE
14-18 July 2014, Amsterdam, The Netherlands
ACCELERATED PHONOLOGICAL DEVELOPEMENT IN WILLIAMS SYNDROME: A TWO CASE CORPUS-BASED STUDY OF LATE PHONOLOGICAL PROCESSES
Verónica Martínez, Aránzazu Antón, Manuela Miranda, Vanesa Pérez,
Joaquín Fernández Toral & Eliseo Diez-Itza
Grupo de Logopedia y Lenguaje Infantil (LOGIN Group), University of Oviedo, Spain
INTRODUCTION
Williams syndrome is a genetic neurodevelopmental disorder caused by a hemizygous deletion on chromosome 7q11.23, characterized by mild intellectual disability and showing an atypical peak- and-valley neuropsychological profile.
Studies in adolescents showed a peak of strength in linguistic production, but in young children a late onset of language has been observed.
As most studies have focused on adolescents, studies on phonological development have been scarce. Although Williams syndrome is often presented as a case of preservation of language, speech development follows an atypical course, showing atypical phonological processing (Majerus, 2004).
METHOD
Subjects:
A boy and a girl with WS aged 5;2.
Two groups of 40 typically developing children (20 boys/20 girls) (Mean Chronological Age: years and 5;9 years respectively).
Procedure:
Subjects were videotaped in two sessions with an interval of six months interacting in spontaneous conversations with a researcher. Each conversation was transcribed and analyzed using CHILDES (MacWhinney, 2000).
Phonological errors were classified into five types: Syllable Structure (SS), Substitution (ST), Assimilation (AS), Omission (OM) and Addition (AD). An Error Index was obtained based on lexical production (Frequency of processes / tokens).
OBJECTIVES
To determine if, in the short term, phonological development in WS follows a similar trajectory to typically developing children (TD) for frequency of errors.
To observe if the type of processes in WS differs from TD.
RESULTS
Frequency of phonological processes and Error Index based on Tokens
Subjects
Age
Frequency of processes
Types
Tokens
Error Index
WS Boy
5;2
127
361
1494
8.50
5;8
100
509
2250
4.44
WS Girl
161
385
1399
11.50 27
424
1552
1.73
TD Children
5;3
1433
5060
64215
5.50
5;9
1001
5145
66054
3.25
Frequency of types of phonological processes
Group
Age
Total
Processes
Syllable Structure
Substitution
Assimilation
Omission
Addition TD
5;5.28
2434
55.75
22.14
4.56
11.42
5.87 WS
5;5.12
415
60.40
23.12
3.42
10.05
2.54
CONCLUSIONS
The two WS children studied initially show a delayed phonological development at age 5;2, but within a period of six months they reach the quantitative error levels of typically developing peers. These results indicate an atypically accelerated trajectory of phonological development and are consistent with the claim that specific developmental trajectories can be observed within the framework of atypical epigenesis (Karmiloff-Smith, 2007).
2) The acceleration of phonological development is extraordinary in the case of the girl with WS, and it points out important individual differences in the trajectories of phonological development in WS.
3) The types of processes observed in WS children are not specifically different from typical phonological development at age 5. These results are consistent with the final outcome of phonological development in WS, since WS children reach typical levels of phonological performance in speech despite of atypical phonological processing (Majerus, 2004).
EXAMPLES OF PHONOLOGICAL ERRORS
*CHI: jugá [*] [: jugar] a la tele de los dibufos [*].
%err: jugá=jugar $PHO:SS; dibufos= dibujos $PHO:ST;
*CHI: tene [*] colore [*].
%err: tene=tiene $PHO:ES:RG:VO:CC:SP; colore=colores $PHO:ES:CF;
*CHI: no está malo de la garanta [*].
%err: garanta = garganta $PHO:ES:RG:CT:HT:SP;
*CHI: y <la pentana [*] > [/] # la ventana eta [*] +...
%err: pentana=ventana $PHO:ST:ON:SR; eta = esta $PHO:ES:RG:CT:HT:SP;
*CHI: una punsera [*] [: pulsera]!
%err: punsera = pulsera $PHO:ES:RG:CT:HT:SU;
REFERENCES
Karmiloff-Smith, A. (2007). Atypical Epigenesis. Developmental Science 10, 84–88.
MacWhinney, B. (2000). The CHILDES Project.Tools for analyzing talk: Transcription format and programs. Mahwah, NJ: Lawrence Erlbaum.
Majerus, S. (2004). Phonological processing in Williams syndrome. In S. Bartke, & J. Siegmüller (Eds.), Williams syndrome across languages (pp. 125–142). Amsterdam: Benjamin Publishing Company.
Acknowledgments: This research was supported by grant FFI C03-03 from the Spanish Ministry of Economy and Competitiveness (MINECO).
Corresponding author: Eliseo Diez-Itza, Universidad de Oviedo, Dpto. de Psicología.