We noted in Chapter 1 that experts have often internalized patterns of discourse behaviour characteristic of neurological disorders and their phases which inform their clinical judgements. However, these internalized patterns may not be explicitly recognized and consequently appear as ‘intuitive’ responses. Just as people can often recognize regional or social dialect variation without being able to say precisely what it is they recognize, so the patterns informing clinicians' impressions may not be explicit. Descriptions of discourse can make experts' tacit knowledge about discourse patterns associated with diagnostic groups explicit, in the same way that descriptions of dialect variation can aid dialect recognition. Such descriptions can also be used to model characteristic patterns for healthcare workers and families who may not have experts' breadth of experience.
Beyond explicitness, one role of clinical discourse analysis is to add tools to existing diagnostic resources where diagnosis is still a clinical decision. Another is to provide characterizations for diagnostic categories which are under-investigated. These may help with diagnostic clarification and planning for treatment. A third role for description of discourse is to track change over time both intra-individually and for group applications. There is potential for monitoring developmental and degenerative processes and tracking responses to treatments and interventions. There is also a fourth role which is to improve understanding of relationships between everyday discourse behaviours and neurocognitive function.
In relation to these roles, in this chapter we model study designs which address discourse correlates of diagnoses and monitoring.