Date of Award


Level of Access Assigned by Author

Open-Access Dissertation

Degree Name

Doctor of Philosophy (PhD)




Colin Martindale

Second Committee Member

Jonathan Borkum

Third Committee Member

Marie J. Hayes


This study examined the psychological correlates of asymmetric cerebral activation as measured by electroencephalograph (EEG) recordings. Five content areas were investigated in the context of EEG asymmetry: hierarchical visual processing, creative potential, mood, personality, and EEG asymmetry, and the effect of a mood induction procedure on cognition and EEG asymmetry. Undergraduate participants completed two experimental sessions separated by two to three weeks. Participants completed a comprehensive set of emotion, personality, and creative potential measures, a cognitive task assessing individual differences in hierarchical visual processing. and a short form of the Rorschach inkblot test. Additionally. each participant underwent either a happy or a sad mood induction procedure to examine the effects of mood on verbal and spatial fluency tasks and EEG asymmetry. EEG was measured in frontal, central. and parietal locations. The primary findings regarding the psychometrics of EEG asymmetry suggested that a large proportion of participants show relatively stable EEG asymmetry across two to three weeks. The results failed to replicate previous research suggesting a relationship between hierarchical visual analysis and mood using a Global-Local task. The results also failed to support the hypothesis that the Rorschach could be used as a measure of hierarchical visual analysis. However, Minor Detail location responses on the Rorschach correlated positively with negative affect and negatively with positive affect. Regarding creativity, the Rorschach was found to be a viable means of assessing individual differences in primary process cognition using the Regressive Imagery Dictionary (Martindale, 1975). Additionally, the results partially supported Martindale's (1 999) hypothesis that creative people show greater right-hemisphere activation. No support was found for the hypothesized relationships between frontal activation asymmetry and mood or personality. Regarding the effect of mood on verbal and spatial fluency, no support was found for the hypothesis that happy moods increase verbal fluency and decrease spatial fluency or that sad moods increase spatial tluency and decrease verbal fluency. Happy and sad mood also did not have a significant effect on EEG asymmetry in the predicted directions. The results are discussed in terms of the status of recent research on EEG asymmetry and its relation to cognition, creativity, emotion and personality.