The experimental method employed for this study of the effects of unconscious conflict on psychopathology consists of presentation of drive-related and neutral pictorial and verbal stimuli at a subliminal level and observing effects on ego functioning. The subjects were stutterers; the aim was to explore the psychoanalytic proposition that the symptom of stuttering includes a regression to areas of conflict involving anal and oral-aggressive impulses. The authors conclude that stutterers manifest an increase in their speech disturbances when anal drive derivatives are triggered without their awareness. A weaker but similar claim is justified: that oral-aggressive derivatives are implicated in intensifying stuttering. It is wisely pointed out that such conditions may be necessary but are not sufficient. Additional requisite conditions would include a high level of drive activation prior to external stimulation, a current state of ego weakness, and sufficient superego pressure.