Williams syndrome (WS) presents a unique window on the cognitive processes that support language processing. Despite the general cognitive impairment that characterizes the syndrome, people with WS show a remarkable preservation of language skills. Therefore, elucidation of the neuropsychological profile in WS may help to determine the minimal set of fundamental cognitive skills that are needed to support language processing. In this project, I propose to study working memory and implicit learning abilities in the WS population. Neuropsychological studies of normal and brain-damaged adults have led to the hypothesis that these two skills contribute to language processing. In particular, it is hypothesized that intact working memory is required for the comprehension of sentences containing complex grammatical constructions, such as embedded relative clauses. This proposal has four specific aims: (1) to determine whether phonological working memory is preserved in WS, relative to visual-spatial working memory, and to determine whether the functional properties of working memory are similar in WS and control subjects; (2) to determine whether implicit learning is preserved in WS, relative to explicit learning (memory); (3) to examine the relationship of working memory and implicit learning skills to language processing in the WS population; and (4) to develop a neurophysiologic probe for cortical activation during working memory and language processing. The first 3 of these aims will be addressed with a combination of experimental and standardized neuropsychological techniques. While my previous research has suggested that phonological working memory is indeed better preserved in WS than is visual-spatial working memory, the tasks proposed here will better isolate these skills and test them closely along theoretical lines. Implicit learning abilities will be tested for the first time in a genetically- defined population with neurodevelopmental abnormalities. The relationship between these skills and language processing also will be tested with neuropsychological techniques. In addition, I propose to develop a functional magnetic resonance imaging protocol to examine cortical activation during tasks of working memory and of grammatical processing. The application of this new technique will address whether these two cognitive functions share a common brain substrate. If evidence is found that working memory and language processing are both functionally and neurologically related, there may be important implications for the educational and medical remediation of children with language impairments.
