Formulaic Language and Language Disorders

The importance of formulaic language is recognized by many branches of the language sciences. Second language learners acquire a language using a maturationally advanced neurological substrate, leading to a profile of formulaic language use and knowledge that differs from that of the prepuberty learner. Unlike the considerable interest in formulaic language seen in second language learning, attention paid to this theme in clinical communicative disorders has been limited. Historically, verbal expressions preserved in severe nonfluent aphasia, including counting, interjections, and memorized phrases, have been referred to as automatic speech. Closer examination of all forms of aphasic speech reveals a high proportion of formulaic expressions, while speech samples from persons with right hemisphere and subcortical damage show a significant impoverishment. These findings are supported by studies of persons with Alzheimer's disease, who have intact subcortical nuclei and abnormally high proportions of formulaic expressions, and Parkinson's disease, which is characterized by dysfunctional subcortical systems and impoverished formulaic language. Preliminary studies of schizophrenic speech also reveal a paucity of formulaic language. A dissociation between knowledge and use of the expressions is found in some of these populations. Observations in clinical adult subjects lead to a profile of cerebral function underlying production of novel and formulaic language, known as the dual processing model. Whereas the left hemisphere modulates newly created language, production of formulaic language is dependent on a right hemisphere/subcortical circuit. Implications of the dual process model for evaluation and treatment of language disorders are discussed.