Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)




The hypothesis that frontal EMG levels measured by surface electrodes change as a function of the number of years of muscle contraction headache activity was tested. Three levels of muscle contraction headache chronicity ((GREATERTHEQ)20 years, (LESSTHEQ)10 years, and none) were examined under imagined stress and a quiz falsely presented as a measure of intelligence. The two stress conditions were counterbalanced across subjects. The three groups had 10 members each and were equivalent in age and subjects' ratings of the laboratory stressors. Psychophysiological recordings were done during a headache free period. An ANOVA indicated no group effect and no group x trials interaction. An ANCOVA showed that frequency of headache during the month prior to psychophysiological recording had no effect on the ANOVA results. Baseline frontal EMG levels, responses to laboratory stressors, and recovery from laboratory stress were not associated with either having a history of muscle contraction headaches nor the length of headache history. These findings suggest that structural changes do not occur as a result of muscle contraction headache. The assumption that increased muscular responses occur as a response to life stress, as stated in the standard definition of this type of headache, is questionable if there is a positive correlation between laboratory and life stressors. A further implication of these results is that decreased headache following frontal EMG biofeedback treatment is the result of factors other than learning to decrease frontal EMG levels. It remains possible that there are subgroups of muscle contractions headache sufferers. However, chronicity of the problem is not associated with frontal EMG levels. Furthermore, these findings add to the body of literature suggesting that EMG levels do not contribute to an understanding of the disorder.