A Longitudinal Assessment of Diverging Verbal and Non-Verbal Abilities in the Williams Syndrome Phenotype

Using developmental trajectories to examine verbal and visuospatial short-term memory development in children and adolescents with Williams and Down syndromes

“…Verbal performance did not develop at a typical rate across time, but was faster to improve than non-verbal performance, with difference between the two domains increasing in line with verbal ability. Although these data were cross-sectional, and as such did not enable a direct inspection of skill development within individuals, a longitudinal investigation involving testing the same group six times over approximately forty months (Jarrold, Baddeley, Hewes, & Phillips, 2001) showed that verbal skills were again faster to develop. Further, the magnitude of verbal/non-verbal differences increased significantly over time.…”

“…The within-group analyses comprised planned comparisons between the verbal and visuospatial STM developmental patterns, within each group, to: (1) investigate differences in performance levels and/or developmental rate across STM domains; (2) assess whether a faster rate of verbal than visuospatial development found for general ability levels in individuals with WS (Jarrold et al, 2001) is also observed in STM performance; and (3) establish whether a corresponding pattern, whereby the development of visuospatial STM outstrips that of verbal STM, is evident in individuals with DS. These analyses were undertaken using MA, then CA, as the developmental index variable, in order to build as comprehensive a picture as possible by examining the influence of each in turn.…”

“…These analyses were undertaken using MA, then CA, as the developmental index variable, in order to build as comprehensive a picture as possible by examining the influence of each in turn. Plotting skill development against CA, the developmental variable employed by Jarrold et al (2001), enabled a direct assessment of whether the verbal/visuospatial chronological divergence suggested by those authors also applies to STM.…”

A Longitudinal Study of Cognitive Abilities in Williams Syndrome

“…Specific hypotheses included: (1) That individuals with WS will follow a typical developmental trajectory over time, showing similar standard scores for general intellect and more specific cognitive abilities at time 1 and time 2; (2) That raw scores will indicate no loss of previously acquired skills; and (3) That personal profiles of cognitive strength and weakness will remain consistent in individuals with WS over time. Given that some research indicates a relationship between cognitive ability and chronological age in WS (e.g., Jarrold et al, 2001), we will also take chronological age into account when considering these questions. Findings are discussed in relation to practical and theoretical implications.…”

Studying Interactions, Reactions, and Perceptions: Can Genetic Disorders Serve as Behavioral Proxies?

“…In Down syndrome, the pattern of visual-overauditory short-term memory becomes more pronounced as the child develops, particularly during the age period from 15 to 21 years (Hodapp & Ricci, 2002). In Williams syndrome, longitudinal evidence (6 testings over a 4-year period) shows that these children's relatively strong abilities in vocabulary develop at a much faster rate than their (already weaker) visuo-spatial skills (Jarrold, Baddeley, Hewes, & Phillips, 2001).…”