Naming and semantic processing of action-related stimuli following right versus left hemispherectomy

Previous neuroimaging research has shown left hemisphere dominance during the semantic processing of embodied action-related stimuli. The goal of our research was to examine how action-related stimuli are processed in individuals after right or left hemispherectomy. S.M. (right hemispherectomy), J.H. (left hemispherectomy), and healthy control participants completed naming and semantic generation tasks with picture and word stimuli with referents that are used by arms or legs. Our results showed evidence of a dissociation for pictures of objects used by legs. Specifically, the naming task showed that, relative to controls, S.M. is impaired on accuracy, whereas J.H. performs closer to normal levels. For the semantic generation task, the opposite result was obtained and is consistent with the response time data. Our results suggest that the right hemisphere is critical for normal picture naming, whereas the left hemisphere is critical for normal semantic generation of action-related knowledge.

► For semantic generation tasks, only the remaining right hemisphere shows impairment on accuracy. ► For naming tasks, the remaining left hemisphere shows greater impairment on accuracy. ► For semantic generation tasks, the remaining right hemisphere shows greater impairment on response time. ► For naming tasks, the remaining left and right hemispheres show similar impairment on response time.