Production of procedural discourse in aphasia.

The abilities of a group of 15 moderately impaired aphasics and 15 normals to produce procedural discourse are described. The experimental tasks included producing four procedures of varying levels of complexity. The data were analyzed in terms of sentential grammar, discourse grammar, and subjective ratings of content and clarity of language. The results showed that aphasics produced well-structured discourse. The language of the aphasics' discourse was reduced in both complexity and amount, but was not qualitatively different from the language produced by the normals. The reduction of language in the procedures reflected selective reduction of hierarchically organized information. The investigation suggests that aphasics are capable of manipulating different types of information and that they might be helped in this by utilizing instrumental scripts which are representation of knowledge underlying procedures.