Marie Smith, EDL750 Language Acquisition

1. Down’s Syndrome and William’s Syndrome and Phonology Marie Smith, EDL750 Language Acquisition

2. Phonology • Phonology is the study of sounds and speech patterns that occur within language. Phonology describes the way sounds function within a given language.

3. Down’s Syndrome • Down’s Syndrome, also known as trisomy 21, is a chromosomal condition caused by having too many copies of the genes located on chromosome 21. • Down’s Syndrome is the most common chromosome abnormality in humans. • According to Martin (2009) Down’s Syndrome is the most common genetic cause of intellectual disability.

4. Down’s Syndrome • In Down’s Syndrome spoken language can be problematic sometimes due to differences in facial muscles and oral structure such as a larger tongue and smaller palette. • Narrow auditory canals result in a susceptibility to Otitis media – inflammation or infection of the middle ear. This can lead to fluctuations in clarity of hearing or in some caseshearing loss, which occurs in approximately two thirds of children with Down’s Syndrome. • These additional factors make it more difficult for individuals with Down’s Syndrome to develop clear well-articulated spoken language.

5. Down’s Syndrome and Phonology • Children with Down’s Syndrome are slow to acquire the phonological system of their mother tongue. • In spite of normal or nearly normal pre-linguistic development, these children are delayed in the use of meaningful speech and slow to acquire a productive vocabulary.

6. Down’s Syndrome and Phonology Factors affecting phonological acquisition • Cognitive deficit • Hearing loss • Differences in anatomy and physiology • Language learning environment

7. Down’s Syndrome and Phonology • In general, word productions of children with Down’s Syndrome have the same phonological characteristics as those of children with typical development (Dodd & Leahy, 1989; Rosenberg & Abbeduto, 1993). • In particular, stop, nasal and glide consonants tend to be produced accurately while fricatives, affricates and liquids are often in error (Bleile & Schwarz, 1984; B.L. Smith, 1984; Stoel-Gammon, 1980, 1981). • Phonological process analyses have also highlighted similarities between children with Down’s Syndrome and those with typical development with the following patterns occurring frequently: (1) consonant clusters are produced as singleton consonants; (2) word-final consonants are omitted; (3) target fricatives and affricates are produced as stops; (4) aspirated voiceless stops in initial position are deaspirated; (5) word-initial liquids are produced as glides and word-final liquids are produced as vowels or are omitted; and (6) word-final voiced obstruents are devoiced (Van Borsel, 1996; Cholmain, 1994; Dodd, 1976; Kumin, Councill & Goodman, 1994; Mackay & Hodson, 1982; B.L. Smith & Stoel-Gammon, 1983; Stoel-Gammon, 1980, 1981). • As might be expected, however, phonological acquisition in children with Down’s Syndrome proceeds more slowly than in their cognitively typical peers.

8. William’s Syndrome • William’s Syndrome is a rare neurodevelopmental disorder characterized by a distinctive "elfin" facial appearance, hypersensitive hearing, low muscle tone, cardiovascular problems, along with a low nasal bridge, a cheerful demeanor and ease with strangers. • It is caused by a deletion of about 26 genes from the long arm of chromosome 7. • The syndrome was first identified in 1961 by Dr. J. C. P. Williams of New Zealand.

9. William’s Syndrome Common features of Williams syndrome include: • Characteristic facial appearance : small upturned nose, long upper lip length, wide mouth, full lips, small chin, and puffiness around the eyes. Blue and green-eyed children with William’s Syndrome can have a prominent "starburst" or white lacy pattern on their iris. • Heart and blood vessel problems • Hypercalcemia(elevated blood calcium levels) • Low birth-weight/slow weight gain. Most children with Williams syndrome have a slightly lower birth-weight than their brothers or sisters. Slow weight gain, especially during the first several years of life, is also a common problem and many children are diagnosed as "failure to thrive". Adult stature is slightly smaller than average. • Feeding problems Many infants and young children have feeding problems. These problems have been linked to low muscle tone, severe gag reflex, poor suck/swallow, tactile defensiveness etc. Feeding difficulties tend to resolve as the children get older. • Irritability (colic during infancy) • Dental abnormalities • Kidney abnormalities • Hernias Inguinal (groin) and umbilical hernias are more common in William’s Syndrome than in the general population. • Hyperacusis (sensitive hearing) • Low muscle tone and joint laxity. • Overly friendly (excessively social) personality • Developmental delay, learning disabilities and attention deficit disorder • Young children with William’s Syndrome often experience developmental delays. Milestones such as walking, talking and toilet training are often achieved somewhat later than is considered normal.

10. William’s Syndrome and Phonology • Individuals with William’s Syndrome typically have strong language abilities despite mild to moderate mental retardation. • Overall brain volume is reduced in William’s Syndrome. • Brain cell size and density may contribute to the strengths in auditory phonology, language and music.

11. Language Development Down’s Syndrome & Language William’s Syndrome & Language Despite considerable individual variability, receptive language is typically stronger than expressive language, with particular challenges in phonology and syntax. Children with William’s syndrome often have developmental delays coupled with strong language skills. William’s syndrome has frequently been cited as evidence that language is independent of cognition.

12. William’s Syndrome and Phonology • Phonology refers to the processing of the sound system of a language, and is often considered to be a relative strength in William’s Syndrome. In particular, it has been widely argued that phonological short-term memory skills represent a peak ability. • Studies have also investigated whether phonological processing mechanisms develop atypically, with claims of a reduced influence of long-term phonological and semantic knowledge on phonological short-term memory.

13. William’s and Down’s • Most studies of phonology in William’s Syndrome have looked at performance on phonological short-term memory tasks such as immediate serial recall. • Individuals with William’s Syndrome consistently perform better on digit and word span tasks than individuals with Down’s Syndrome. • Down’s Syndrome is associated with severe deficits in phonological short-term memory.

14. Down’s and William’s • Studies looking in more detail at phonological short term memory have consistently failed to find evidence for atypical effects of phonological factors in William’s Syndrome such as word or nonword length and phonological similarity. • In contrast, a number of studies have reported evidence for reduced effects of long-term word knowledge. • Most prominently, Vicari (1996) observed a reduced effect of word frequency in William’s Syndrome, leading the authors to propose that individuals with William’s Syndrome arehyperphonologicalrelying excessively on phonological coding. • Complementary results were reported by Majerus et al. ~2003, who noted reduced effects of word frequency, lexical status, and phonotactic frequency ~the frequency of phoneme combinations in the native language on the performance of some individuals with William’s Syndrome. • Individuals with William’s Syndrome demonstrated entirely normal effects of lexical knowledge on phonological short term memory.

15. Down’s and William’s • Compared to other groups with developmental delays, individuals with William’s Syndrome appear to have relatively good speech production. • Their phonological short-term memory capabilities are better than those of individuals with Down’s Syndrome.

16. Down’s and William’s • Individuals with William’s Syndrome consistently outperform controls with Down’s Syndrome on tests of phonology and syntax. • An obvious and important question that remains unanswered is why language appears to develop relatively normally in William’s Syndrome but is severely impaired in Down’s Syndrome.

17. Down’s and William’s and Phonology • Very young children with Down’s Syndrome and William’s Syndrome both have delayed language acquisition, which affects how they initially attach sounds to letters which is phonology and how they understand new words which is morphology. • Please welcome Tara, she will be discussing morphology.