Differential processing of implicature in individuals with left and right brain damage

To evaluate the processing ability of implicature , especially indirect request and indirect refusal, the Four Scenes Test was administered to 20 left hemisphere damaged (LHD) subjects, 20 right hemisphere damaged (RHD) subjects and 15 normal control subjects. The results showed first, that the performances of the brain-damaged subjects was inferior to that of the control subjects in processing implicature; second, that indirect request understanding was easier than indirect refusal understanding in the brain-damaged subjects, and the third that indirect refusal understanding in of the left hemisphere damaged subjects was inferior to that of the right hemisphere damaged subjects. There was no group difference in indirect request understanding though the ability of brain-damaged subjects was poorer than that of the normal controls. These findings suggest that LHD and RHD subjects were not the same in implicature processing and their responses depended on the implicature's modularity (refusal and request).