Modelling non-specific linguistic variation in cognitive disorders

Clinical linguistic diversity extends far beyond ‘specific language’ disorders, such as acquired aphasia or specific language impairment (SLI), to a large range of mental disorders that are not language-specific. As cognitive impairments are involved in the latter, models with an integrated approach to language and cognition can be useful for understanding and classifying the variation in question. The aim of this paper is to specify such a model, called the Bridge model, which views linguistic cognition as resting on two partially pre-linguistic pillars: (i) perceptual categorisation and (ii) social-communicative interaction. Grammar acting as a bridge crossing between them mediates the lexicalisation of perceptual categories and, based on these, new forms of social interaction and communication conveying thought structured by grammar. This model allows to conceptualise mental disorders as different ways in which this integrated linguistic-cognitive phenotype can deviate from its normal course. We illustrate our general model for the specific instance of language variation within autism spectrum disorder (ASD).