Perspectives on the dynamic development of cognitive capacities:  insights from Williams syndrome.
OBJECTIVE
This article identifies an increasing change from rather static approaches to neurodevelopmental disorders and the search for 'intact' and 'impaired' domain-specific modules, to more recent dynamic perspectives that take account of cross-domain interactions and changes over developmental time.


RESULTS
Research on Williams syndrome is taken as a model, used to demonstrate the static versus dynamic perspectives, covering new work on social cognition, spatial cognition, and sleep-related consolidation of memory in neurodevelopmental disorders, as well as hypothesis-driven cross-syndrome comparisons. Many previously considered 'intact' domains have now been shown to harbour subtle deficits because of the cross-domain interactions typical of early periods of infant development. Sleep architecture has been found to be atypical in all syndromes hitherto assessed, with consequent impact on learning. This has opened avenues for sleep intervention which may impact on subsequent cognitive development.


CONCLUSIONS
Cross-syndrome associations, and not merely cross-syndrome dissociations or comparisons with typical development, are shown to be particularly relevant for advancing theory and research. These comparisons reveal that clinical intervention strategies should aim at syndrome-specific remediation as early in the developmental trajectory as possible.
Birkbeck Centre for Brain & Cognitive Development, University of London, London, UK. a.karmiloff-smith@bbk.ac.uk
Annette
A
Karmiloff-Smith
D003072:Cognition Disorders / Q000209:etiology*; D002658:Developmental Disabilities / Q000150:complications* / Q000523:psychology; D006801:Humans; D012890:Sleep / Q000502:physiology; D012919:Social Behavior; D018980:Williams Syndrome / Q000150:complications* / Q000523:psychology*