Evoked potentials were averaged from different visual stimuli within the same class. Classes of stimuli were: Taboo words, Neutral words, Letters, and Blank flashes. Stimuli within classes were randomized and sequence of classes balanced within a group of six male and six female Ss. Estimates of spectral components showed that the frequencies 2–16 cps contributed significantly more to the averaged evoked response recorded from the class of neutral stimuli than it did any of the other classes when compared with all other classes. Differences between spectral components of other stimulus classes (Taboo, Letters, & Blank) were not significant. An interpretation of the results involving active suppression of the effects of Taboo words is discussed.