Assessing Attention in Children with Williams Syndrome and Down's Syndrome Using a New Comprehensive Attention Battery: Do These Problems Relate to Visual Dorsal Cortical Stream Deficits?

• ¹ University College London, Visual Development Unit,, United Kingdom

Purpose: There are many anecdotal reports of attention problems in both Williams syndrome (WS) and Down’s syndrome (DS), with some recent studies suggesting difficulties on frontal lobe executive function tasks (e.g. Atkinson et al, 2003). However, for many children with WS and DS who have a mental age below 6 years, there has been no standardized single battery to assess the different components of attention (selective attention, sustained attention and attentional / executive control) which are thought to be underpinned by different neural networks of brain areas in the adult brain and in typically developing older children (e.g. Posner & Petersen, 1990; Manly et al, 2001). In the Visual Development Unit, we have recently devised and normalized a new battery designed to assess different attention components in children of 3-6 years mental age (MA), including children with developmental disorders. We report the results of a study using this battery to map profiles of attention in children with WS and DS and consider the relationship between attentional deficits and dorsal stream deficits, as manifested in the comparison of motion and form coherence thresholds (e.g. Atkinson et al, 1997; Braddick et al, 2003).

Methods: There were 8 short subtests in the battery, each test lasting between 2 and 10 minutes. These subtests included a visual search and a flanker task, intended to tap selective attention; vigilance-type sustained attention tasks in visual and auditory modalities; and tests of verbal inhibition, motor inhibition, and sorting with rule shifts to assess aspects of attentional / executive control. Children in the current study completed these new attention tasks, plus measures of verbal and non-verbal intelligence, dorsal and ventral stream processing (motion and form coherence computer game), and global vs. local level visual processing with Navon figures.

Results and discussion: Results to date confirm earlier preliminary data showing marked delays for both groups compared to chronological age and MA, and suggest that sustained attention is less affected than selective or executive attention in both syndrome groups. We will discuss how profiles of attention in these groups relate to (i) the changes in attention seen over the preschool years in typical development, (ii) vulnerability of the dorsal visual stream in developmental disorders, and (iii) known structural and functional brain abnormalities in these groups.