Atypical Cognitive Deficits in Developmental Disorders: Implications for Brain Function

Helen J. Neville The Salk Institute, and University of California, San Diego

Debra L. Mills Ursula Bellugi The Salk Institute

From the perspective of cognitive neuroscience, the great promise of studying populations like those with Williams syndrome is the opportunity to link the extreme degree of variability in their cognitive profiles (see chapter 2 of this volume) to concomitant and specific alterations in cerebral organization. In this endeavor, and in cognitive neurosciences generally, development can be a very powerful tool. In the adult, the brain is highly specified and behavior is optimal and so the amount of variability in both systems is typically low. In contrast the developing organism displays a high degree of change both in different neural systems and in cognition, and thus provides an important opportunity to link variability in one trajectory to variability in the other. In the case where more than one brain system and related cognitive abilities develop along a similar timecourse, populations with specific structural damage and, the topic of this volume, populations with specific patterns of deficient and spared cognitive functions, can contribute in important ways to the separation of cognitive processes and the identification of related brain systems.

Although the developmental perspective can significantly amplify the

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