Theoretical Considerations for Understanding "Understanding" by Adults With Right Hemisphere Brain Damage.

This article reviews and evaluates leading accounts of narrative comprehension deficits in adults with focal damage to the right cerebral hemisphere (RHD). It begins with a discussion of models of comprehension, which explain how comprehension proceeds through increasingly complex levels of representation. These models include two phases of comprehension processes, broad activation of information as well as pruning and focusing interpretation of meaning based on context. The potential effects of RHD on each processing phase are reviewed, focusing on factors that range from relatively specific (e.g., how the right versus the left hemisphere activate word meanings; how the right hemisphere is involved in inferencing) to more general (the influence of cognitive resource factors; the role of suppression of contextually-irrelevant information). Next, two specific accounts of RHD comprehension difficulties, coarse coding and suppression deficit, are described. These have been construed as opposing processes, but a possible reconciliation is proposed related to the different phases of comprehension and the extent of meaning activation. Finally, the article addresses the influences of contextual constraint on language processing and the continuity of literal and nonliteral language processing, two areas in which future developments may assist our clinical planning.