Correct information unit analysis for determining the characteristics of narrative discourse in individuals with chronic traumatic brain injury

Primary objective: To investigate differences between individuals with traumatic brain injury (TBI) and a control group regarding quantitative characteristics of narrative discourse including correct information units (CIUs). The secondary objective was to explore cognitive correlations with narrative discourse measurements. Research design: Case-control study. Methods: Twenty-six individuals with TBI and 24 age-, gender- and education-matched subjects without brain injury were examined. Four-frame comic strips were used for elicitation of narrative discourse. Six variables of discourse measurements (total time, total number of units and CIUs, units per time, CIUs per time and CIUs per unit) were calculated. The relationships between the 6 discourse measurements and results of standard cognitive tests were also examined, including logical memory, working memory and executive functions. Main outcomes and results: The time efficiency for narrative discourse (i.e. total time, units per time and CIUs per time) was significantly decreased in the TBI group. Moreover, time efficiency was significantly related to measurements of working memory and executive function. The TBI group did not differ from the control group with regard to total number of units and CIUs and CIUs per unit. Conclusion: Decreased time efficiency is the most critical characteristic of narrative discourse in individuals with TBI.