Discourse information content in non-aphasic adults with brain injury: a pilot study

Background: The functional evaluation of discourse informativeness is widely used in both clinical practice and research, and impoverished and confused discourse has been described in individuals with traumatic brain injury (TBI). These symptoms have been related to language processing deficits at the macrolinguistic level. However, the functional counterpart of these deficits, i.e. poor informativeness in standardized analysis of elicited speech samples, has been less explored. Methods and procedures: In this pilot study, samples of narrative discourse from 10 non-aphasic TBI adults and 28 healthy adults were examined to study the relationship between standardized measures of informativeness (i.e. Correct Information Unit analysis) and language processing errors at the macrolinguistic level and to compare performance of the two groups. Main outcomes and results: The participants with TBI did not produce relevant within-sentence errors and information content of their narratives was not different from that of the healthy participants. However, their production of errors of cohesion, local coherence and global coherence was significantly greater. These macrolinguistic errors corresponded to reduced levels of information efficiency (% CIUs score). Conclusions: Functional measures of speech informativeness such as the CIU scores may be useful for the clinical assessment of discourse processing deficits in TBI individuals without aphasic symptoms.