Language `off-line'

Abstract

Individuals with the rare genetic disorder, Williams syndrome (WMS), are of particular interest to cognitive neuroscientists because of the well-known dissociation between intact language abilities and severely impaired spatial abilities[ 1 St George M. What studying genetically-based disorders can tell us about ourselves. Trends Cognit. Sci. 1998; 2: 203-204 Abstract Full Text Full Text PDF PubMed Google Scholar ]. This dissociation is often used to support claims of an innate, genetically determined grammar module. Some reports have challenged this view, however, and recently Karmiloff-Smith et al.[ 2 Karmiloff-Smith A. et al. Linguistic dissociations in Williams syndrome: evaluation of receptive syntax in on-line and off-line tasks. Neuropsychologia. 1998; 36: 343-351 Crossref PubMed Scopus (90) Google Scholar ]provided further evidence that might force a rethink of whether all aspects of language are intact in individuals with WMS. These authors used both `on-line' (implicit) and `off-line' (explicit) tasks to examine the processing of receptive syntax. The on-line task, which required monitoring sentences for target words, revealed an impairment in the processing of the specific syntactic construction called subcategorization. This particular syntactic construction is often acquired later in development than other aspects of syntax, and also causes difficulties for second-language learners. Two other aspects of syntax examined on-line were performed normally, whereas all seven types of syntactic construction examined off-line, which required matching sentences to appropriate pictures, were performed very poorly. This study reaches two important conclusions: that there is a need for both on-line and off-line tasks in the investigation of language disorders; and that at least one aspect of language processing in WMS is not intact.