Executive neuropsychological functioning in individuals with Williams syndrome.

The present study investigated executive neuropsychological functioning in individuals with the neuro-developmental disorder Williams syndrome (WS) using a set of validated standardized neuropsychological tasks. Relatively few studies have examined frontal lobe related executive functions within the cognitive phenotype associated with the disorder. The present study compared participants with WS to typically developing participants who were individually matched for (1) chronological age and (2) verbal mental age (N=19 each group) on tasks of attention-set shifting, planning and working memory from the Cambridge Neuropsychological Test Automated Battery (CANTAB). To address the specificity of executive function impairment, non-executive tasks of delayed short-term memory and short-term memory span were also administered. Individuals with WS (mean age 18 years) showed impaired executive functioning on tasks of attention set-shifting, working memory, and planning. Non-executive deficits were also observed in short-term delayed memory and memory span. Neuropsychological impairments were correlated with a range of behavioural problems assessed using parent-rated Questionnaires. Overall, these findings point to the role of a range of executive function impairments in WS but further suggest that cognitive impairments extend beyond executive dysfunction.