Date of Award
Doctor of Philosophy (PhD)
Studies on the differential contributions of the cerebral hemispheres to human experience and behavior have demonstrated that the hemispheres are lateralized for cognitive strategies and, possibly, for emotional valance. Recently researchers have demonstrated that the hemispheres may also be lateralized for certain personality disorders and personality traits. Using lateral eye movements as a measure of hemispheric activation, Dawson, Tucker, and Swenson (in preparation) have shown that certain self-description questionnaires may serve to discriminate subjects who characteristically utilize one hemisphere over the other, regardless of the relative adaptiveness of the cognitive strengths of that hemisphere for the task at hand.
This study replicated the findings of the Dawson et al. study, using brain wave activity as an index of lateralized activation. Separating subjects on the basis of their scores on self-description personality measures, it was discovered that subjects who were unrealistically favorable in their self-descriptions (deniers) evidenced greater right hemisphere activation, regardless of the task being performed. Subjects who were overly critical in their self-descriptions (critics) evidenced symmetrical hemispheric activation with a tendency toward greater left hemispheric activation, particularly evident during the baseline and spatial tasks. These findings were evidenced in both the theta and alpha bands for average power, with comparisons in the theta band demonstrating the clearest personality related effects. Analyses on coherence data were performed and described without interpretation.
The results of this study were used to provide support for a theory of hemispheric personality. A model is built on the research findings on lateralized cognition and then extended to address some of the recent controversies in the lateralization literature. Implications for further research are discussed and suggestions of how such a model might be used in psychological/medical treatment and diagnoses are discussed.
Dawson, Steven L., "The Construct of Personality and Hemispheric Usage" (1983). Theses and Dissertations. 1161.