William’s Syndrome vs. Down’s Syndrome

1. William’s Syndrome vs. Down’s Syndrome Morphology

2. Morphology • Recap

3. Morphology • Smallest unit of meaning • Free morphemes-can stand alone- bat, cat, life, guard • Bound morphemes- must bind to free morphemes to change word meaning (Bat+ /s/=bats, bat+ing=batting) • “Morphology denotes the use of grammatical affixes that mark, for example, tense, number, and (in some languages) gender” (Brock, 2007, p.111)

4. William’s Syndrome and Down’s Syndrome • Vocabulary acquisition develops atypically (Nazzi & Karmiloff-Smith, 2002). • They have difficulty mastering the basic skills involved in lexical acquisition.

5. Cues for Vocabulary Acquisition • Typical developing children use multiple cues to determine the meanings of words • Ex: when adult names an object, he or she is referring to the object they are attending • However, younger children with William’s and Down’s have shown difficulty with matching object to verbal cue

6. Williams vs. Down’s • Acquisition of first words is severely delayed in those with Williams-delayed on average until about 28 months (typical children-12-13 months) • Lexical knowledge-children with either syndrome produced and understood similar numbers of words • However, slightly larger vocabularies in Williams (Brock, 2007).

7. Williams • In assessing grammatical complexity through the use of utterances, it was found that children with Williams have comparable utterances to typically developing children. • Children with Williams demonstrated a normal relationship between number of different words they used and the complexity of sentences they produced. • All in all, children with Williams showed a normal relationship between grammatical complexity, vocabulary knowledge, and mental age.

8. Down’s • Simpler utterances. • Children with Down’s showed poorer than predicted by their lexical repertoire (Brock, 2007).

9. Lexical Memory • Additionally, lexical memory is impaired. • This is evidenced from past tense elicitation • They have difficulty understanding the past tense of words as well as forming the past tense of regular and irregular words • Those with William’s syndrome have a higher performance in assessments of lexical and grammatical abilities than those with Down’s syndrome (Papaeliou et. Al, n.d.).

10. Williams vs. Downs • In a study conducted on infants and adults, it was found that individuals with Down’s syndrome have a greater vocabulary impairment as compared to those with Williams (Paterson, 2001). • Both were equally able to match a word to its referent between 24-36 months. • Both groups were equally delayed in language acquisition • As compared to adults with the syndromes, adult data suggests that vocabulary comprehension in those with Williams would be higher than those with Down’s.

11. Receptive Vocabulary • Older adults with Williams perform better on tasks than was expected on basis of overall mental age, nonverbal reasoning skills, or visuospatial reasoning abilities. • Receptive vocabulary of adolescents with Williams was better than predicted by their chronological age and nonverbal ability • However, those with Down syndrome had significantly poorer receptive vocabulary scores than predicted

12. Morphology • Overall, children with William’s syndrome perform better on vocabulary and grammatical tasks than those with Down’s syndrome. • In the early stages of childhood, children with William’s and Down’s syndrome both have delayed language acquisition, which affects how they attach sounds to letters (phonology), how they make meaning of new words (morphology), and how they use those new words in different contexts (semantics).