Inferential abilities of normal and right hemisphere damaged adults.

There were two aims of this study. The first was to compare indirect inferencing abilities by nine right hemisphere brain-damaged (RHD) adults with 18 matched normal controls. The second purpose was to determine the best condition in which to present information to the RHD individuals for the purpose of forming these inferences. Three conditions were evaluated: (1) Auditory-Only, (2) Orthographic-Only, and (3) Combined Auditory/Orthographic. It was hypothesized that right hemisphere damaged persons would perform most successfully when the materials (narrative paragraphs) were presented using the combined condition. Both groups performed significantly better in the combined Auditory/Orthographic condition. There were no significant differences in the performances of the RHD group as compared to the normal controls. This suggested that the RHD group did not exhibit an inference impairment on this type of linguistic task.