Background: In 1990, Hough conducted a study investigating the role of theme organization on discourse comprehension in adults with right hemisphere brain damage (RHD). She reported that participants with RHD performed significantly worse when the theme of a narrative was delayed until the end, compared to when the theme was at the beginning. RHD participants also performed significantly worse on these tasks compared to participants with left hemisphere brain damage and normal controls. However, manipulations to delay the theme also resulted in narratives that lacked coherence and violated the rules of narrative structure. Aims: The current study examined if controlling for differences in coherence between original and delayed-theme narratives would eliminate discrepancies in comprehension in the two conditions.Methods & Procedures: Participants were 10 adults with unilateral RHD and five without brain damage. Participants listened to experimental and filler narratives. Experimental narratives consisted of original-theme narratives and delayed-theme narratives that were manipulated to delay the theme while maintaining story coherence. Filler narratives consisted of original-theme narratives and delayed-theme narratives that were not controlled for coherence. All narratives were followed by three yes/no questions pertaining to main ideas and details. Several ancillary tasks were also included to further classify participants and to analyze alternative explanations for performance. Outcomes & Results: Accuracy data revealed that as predicted, there was no significant difference in performance on experimental original-theme and delayed-theme narratives for the RHD group. There was a trend towards poorer comprehension of filler delayed-theme narratives compared to original-theme narratives. These results support the hypothesis that poor comprehension on delayed-theme narratives in Hough's study was a result of differences in coherence rather than theme organization. However, analysis of ancillary tasks revealed a significant correlation between estimated capacity for auditory working memory and performance on delayed-theme narratives. These results imply that even with coherence accounted for, delaying the theme of a narrative is more taxing on mental processing, thus decreasing comprehension in RHD participants with particularly low working memory capacity
