PSYCHOLOGICAL DEFENSE-MECHANISMS AND ELECTROENCEPHALOGRAPHIC AROUSAL

The aim of this study was to examine the relationship between psycholo gical defense as measured by the Kragh tachistoscopic Defense Mechanis ms Test (DMT), and general arousal properties of the individual as mea sured with electroencephalogram (EEG). The DMT assesses defense by pre senting neutral and threatening pictures with very short exposure time s. EEG characteristics were measured in the 8-12 Hz EEG frequency band during DMT testing. Twenty-one male subjects participated in the stud y. All were US Air Force personnel on active duty. Personnel with high defense mechanisms, defined in this connection as slow perception of the threat, tended to have higher cortical arousal after Stimulus expo sure than the subjects with low defense mechanisms. The differences oc curred mainly with new stimulus material without any threatening conte nt. The differences in arousal response to novel stimuli may contribut e to an understanding of the relationships between the Kragh DMT test and performance in life-threatening situations.