Visuo‐spatial and linguistic abilities in a twin with Williams syndrome

Abstract

The present study reports a case of dizygotic twins, one boy with Williams syndrome (WS) and one typically developing girl, and compares their neuropsychological profiles. The goal of the present authors was to verify whether the child with WS displayed a cognitive profile which is unique to the syndrome. Several tests designed to assess visuo-perceptual, visuo-motor, linguistic and memory abilities were administered to both children when they were 10.9 years old. Compared to his sister, the boy with WS displayed a homogeneous developmental delay in both non-verbal and verbal abilities. He achieved a level of performance similar to his sister only in facial recognition, phonological word fluency and memory for phonologically similar words. Furthermore, despite the overall delayed performance of the boy, both the twins displayed a cognitive profile characterized by strength in lexical comprehension and relative weakness in visuo-motor abilities.

del (9p) syndrome: Proposed behavior phenotype

“…Individual case-studies and larger sample studies of linguistic and cognitive performances of WS children demonstrated that there is a wide individual variability Volterra et al, 1999]. The cognitive pro®le may change over time, as the early phases of development are often characterized by a delay of language and visuo-spatial acquisition, with language subsequently catching up at a faster rate than visuo-constructive skills [Jarrold et al, 1998].…”

“…The similarities are striking from a qualitative more than a quantitative point of view and are particularly evident in the language domain for the unusually¯uent and sophisticated mode of expression, in the light of rather poor cognitive resources. It is well known that WS children show, in general, better linguistic than visuospatial and visuo-praxic abilities, though the interpretation of the cognitive pro®le in terms of spared verbal and impaired non-verbal functions is over-simplistic [Capirci et al, 1996;Volterra et al, 1999]. What broadly characterizes most WS patients is, in fact, the presence of areas of serious de®cits and of relative strengths not only across but also within the verbal and the non-verbal domain [Bellugi et al, 1999].…”

“…What broadly characterizes most WS patients is, in fact, the presence of areas of serious de®cits and of relative strengths not only across but also within the verbal and the non-verbal domain [Bellugi et al, 1999]. In the verbal domain, vocabulary is usually better developed than morphosyntactic abilities and phonological working memory is normal [Vicari et al, 1996;Volterra et al, 1999]; within the non verbal domain, face processing is far advanced compared with visuo-constructive and visuo-graphic abilities and to visuo-spatial memory [Bellugi et al, 1990[Bellugi et al, , 1999Karmiloff Smith et al, 1995]. To better demonstrate similarities and differences between the behavioral phenotypes of the del (9p22) syndrome and WS, we selected three patients, from a group of WS children and adolescents followed at our Institute.…”

What atypical populations can reveal about language development: The contrast between deafness and Williams syndrome

“…These studies have been conducted in Great Britain and France as well as in the United States (Arnold, Yule, & Martin, 1985;Karmiloff-Smith, 1992;Rubba & Klima, 1991;Wang & Bellugi, 1993). Our group has contributed to this revised perspective with several studies of linguistic abilities of Italian children with WS Pezzini, Vicari, Volterra, Milani, & Ossella, 1999;Volterra, Capirci, Pezzini, Sabbadini, & Vicari, 1996;Volterra, Longobardi, Pezzini, Vicari, & Antenore, 1999), in order to answer the following questions:…”

Evidence for atypical categorical speech perception in Williams syndrome

“…Second, experimental investigations focused mainly on phonological fluency, phonological awareness and nonword repetition as estimators of phonological and metaphonological abilities. In phonological fluency tasks (e.g., the participant is asked to produce as many words as possible starting with a target phoneme), children and adults with WS generally perform at the same level as mental or even chronological age-matched controls (Barisnikov et al, 1996;Pezzini, Vicari, Volterra, Milani, & Ossella, 1999;Volterra, Capirci, & Caselli, 2001;Volterra et al, 1996;Volterra, Longobardi, Pezzini, Vicari, & Antenore, 1999). However, it must be noted that phonological fluency tasks can also be performed on the basis of acoustic similarity between the target phoneme and the onset of the words.…”